First-Attempt Endotracheal Intubation Success Rate Using A Telescoping Steel Bougie

Evan D. Schmitz, MD

La Jolla, CA USA

Kevin Park, MD, MBA, FCCP 

MLK Community Medical Group

Compton, CA USA 

Abstract

Background

There has been a renewed interest in using the plastic intubation bougie to facilitate first-attempt endotracheal intubation success. The sterile single-use telescopic steel bougie (AIROD) was invented to overcome the limitations of the plastic bougie which is easily deformed during storage.  

Methods

This is a retrospective study involving critically ill patients who were intubated with the AIROD in the intensive care unit at a single institution. The purpose of this case series is to compare the success rate of the AIROD to the generally accepted success rate for the traditional plastic bougie of 96%.

Results

A total of 54 patients were enrolled at a single ICU over a 10 months period. All patients were critically ill with 76% having a difficult airway, Cormack-Lehane grade view 2 or greater in 60%, and ARDS secondary to COVID-19 in 54%. The primary outcome of first-attempt intubation success in critically ill patients intubated in the ICU with the AIROD was 97% with a 95% confidence interval of 0.89 to 0.99. The average time for intubation of all airway classifications was 15 seconds.

Conclusion

The AIROD first-attempt intubation success rate was found to be similar to the rate for the traditional plastic bougie.

Introduction

The BEAM (Bougie Use in Emergency Airway Management) trial, renewed interest in the use of a bougie rather than a stylet (1). In the BEAM trial, first-attempt endotracheal intubation success using a plastic bougie was compared to a stylet during laryngoscopy in an emergency department. First-attempt success was achieved in in 98% compared to 87% in all patients. In patients with at least one difficult airway characteristic, first-pass success using a plastic bougie was 96% compared to 82% using a stylet.

In 2019, the sterilized single-use telescopic steel bougie, AIROD (AIRODMedical; FL, USA), was introduced to the USA market (Figure 1).

Figure 1. A: AIROD closed. B: AIROD open. C: AIROD with an endotracheal tube loaded on the distal end.

The thin surgical steel construction of the AIROD allows it to bend slightly while maintaining its integrity to help manipulate oropharyngeal tissue without causing trauma. The AIROD can guide a 6.5 mm or larger endotracheal tube into the trachea. To do so, the AIROD is introduced into the oropharynx alongside a laryngoscope, either direct or video, and advanced just past the vocal cords. An endotracheal tube is then slid down over the AIROD and into the trachea securing the airway to allow for mechanical ventilation. The AIROD telescopes from one foot when closed to two feet when opened, offering many storage options.

Several publications have demonstrated that the AIROD is a safe and effective tool for endotracheal intubation (2-5). In this manuscript we extend those observations.

Methods

A retrospective analysis of all endotracheal intubations that were performed with the AIROD in the ICU at a single institution (Mercy One Hospital in Sioux City, IA) between October 18, 2020 and January 1, 2020 were included.

A successful first-attempt intubation was defined as the placement of an endotracheal tube into the trachea upon the initial insertion of the laryngoscope into the oropharynx. If the laryngoscope had to be removed and a second-attempt performed, it was considered a failure. Airways were graded using the Cormack-Lehane grade view (Appendix 1).

A difficult airway was defined as the presence of body fluids obscuring the laryngeal view, airway obstruction or edema, obesity, short neck, small mandible, large tongue, facial trauma, stiff neck or the need for cervical spine immobilization (2). Intubation time was defined as the time from insertion of the laryngoscope to placement of an endotracheal tube with its cuff inflated.

Results

Patient characteristics are shown in Table 1. 

Table 1. Characteristics and outcomes of the critically ill patients intubated with the AIROD in the ICU.

A total of 54 patients with an average age of 62 years were included in the study. All patients were in critical condition. The average patient was obese with a BMI of 31.2 kg/m2. A difficult airway was present in 76% of the patients and 54% of the patients had COVID-19 infection. In total, 63% of the patients were male and 37% were female. Using the Cormack-Lehane grade view: 20% had a grade 4 view, 10% had a grade 3 view, and 30% had a grade 2 view.

Intubation first-attempt success rate was 97%. Subgroup analysis of first-attempt intubation success using the AIROD to intubate in patients with a difficult airway was 96%.

The average intubation time in the patients that were timed was 15 seconds (33/54 patients were timed). Of the patients with a difficult airway, the average time to intubate was also 15 seconds.

A bronchoscopy performed on 17% of the patients just after intubation revealed no evidence of tracheobronchial trauma.

Discussion

The patients intubated with the AIROD in the ICU had a first-attempt success rate of 97%. The first-attempt success rate for endotracheal intubation of the critically ill has been reported at only 70% (6,7). This corresponds to an absolute risk reduction of 27% in failure to intubate patients during the first-attempt with the use of the AIROD during the intubation of patients in critical condition.

Even when compared to patients who were not critically ill and were intubated with a plastic bougie in the emergency department in the BEAM trial (1), the first-attempt success rate with the AIROD was 97% vs. 98. In those patients who were critically ill and also had a difficult airway, the first-attempt intubation success rate with the AIROD was at 97% vs. 96% in all patients (not just the critically ill) with a difficult airway.

In this study, the average time to intubation in all critically ill patients was 15 seconds using the AIROD. For those patients who were critically ill and had a difficult airway, the time to intubation was also 15 seconds. A previous publication on consecutive COVID-19 patients with ARDS intubated using the AIROD also had an intubation time of 15 seconds (2). In the BEAM trial, the median time to intubation using the plastic bougie in all types of patients intubated in the emergency department was 38 seconds (1). In all critically ill patients, the AIROD was 23 seconds faster. Intubation with the AIROD took 40% of the time in those patients who were critically ill, including those with a difficult airway, as opposed to the plastic bougie. The decrease in time securing the airway may have an impact on overall decompensation and possible outcomes of the disease process. Further studies between low intubation time and disease outcome remain an area to be studied in the future. The decrease in intubation time using the AIROD was not accompanied by adverse events such as cardiac arrest or tissue damage.

During multiple intubations, the AIROD was used to lift the epiglottis and move the oropharyngeal tissue that was obscuring the vocal cords out of the way, improving the view of the vocal cords and allowing for successful tracheal intubation. The AIROD was also able to move copious secretions blocking the view of the glottis in a few patients including those patients receiving chest compressions. Even during blind intubation, including one time when the light on the laryngoscope failed, the AIROD provided tactile sensation to the tracheal rings known as “tracheal clicks” that helped ensure correct tracheal placement of the endotracheal tube (2).

This study is limited by its small sample size and retrospective nature, and by that fact that not all intubations were timed because of the emergent nature of some of the intubations. The inventor of the AIROD did most of the intubations and others might not achieve equal results. A prospective trial on the timing of first-pass intubation success using the AIROD would be most useful to confirm the findings in this study.

In conclusion, the AIROD first-attempt intubation success rate was found to be similar to the rate for the traditional plastic bougie. Direct inspection of the oropharynx during intubation confirmed no significant trauma occurred during intubation.

Conflicts of Interest

Evan D. Schmitz, MD is the inventor of the AIROD and was the primary operator for most of the intubations mentioned in this study. No financial assistance was provided for this study. The AIROD instruments were donated to the hospital from AIRODMedical.com.

Acknowledgments

The author thanks H. Carole Schmitz, Carol Fountain and Abra Gibson for their editorial comments.

References

1. Driver BE, Prekker ME, Klein LR, Reardon RF, Miner JR, Fagerstrom ET, Cleghorn MR, McGill JW, Cole JB. Effect of Use of a Bougie vs Endotracheal Tube and Stylet on First-Attempt Intubation Success Among Patients With Difficult Airways Undergoing Emergency Intubation: A Randomized Clinical Trial. JAMA. 2018 Jun 5;319(21):2179-2189. [CrossRef] [PubMed]
2. Schmitz ED. Decreasing COVID-19 patient risk and improving operator safety with the AIROD during endotracheal intubation. J of Emergency Services. EMSAirway. 11/2020.
3. Schmitz ED. AIROD Case Series: A new bougie for endotracheal intubation. J Emerg Trauma Care. 2020;5(2):20. [CrossRef]
4. Schmitz ED. Single-use telescopic bougie: case series. Southwest J Pulm Crit Care. 2020;20(2):64-68. [CrossRef]
5. Schmitz ED, Park K. Emergency intubation of a critically ill patient with a difficult airway and avoidance of cricothyrotomy using the AIROD. J of Emergency Services. EMSAirway. 01/2021. [CrossRef]
6. Collins SR. Direct and indirect laryngoscopy: equipment and techniques. Respir Care. 2014 Jun;59(6):850-62; discussion 862-4. [CrossRef] [PubMed]
7. Higgs A, McGrath BA, Goddard C, Rangasami J, Suntharalingam G, Gale R, Cook TM; Difficult Airway Society; Intensive Care Society; Faculty of Intensive Care Medicine; Royal College of Anaesthetists. Guidelines for the management of tracheal intubation in critically ill adults. Br J Anaesth. 2018 Feb;120(2):323-352. [CrossRef] [PubMed]

Cite as: Schmitz ED, Park K. First-Attempt Endotracheal Intubation Success Rate Using A Telescoping Steel Bougie. Southwest J Pulm Crit Care. 2021;22(1):36-40. doi: https://doi.org/10.13175/swjpcc004-21 PDF

Single-Use Telescopic Bougie: Case Series

Evan Denis Schmitz MD

La Jolla, CA USA

Abstract

AIROD^TM is a single-use telescopic bougie that is small enough to fit into a pocket. AIROD^TM is sterile and can be expanded in hast when needed, saving precious seconds, while attempting to intubate a patient. The non-malleable bougie is able to overcome the compressive force of the oropharyngeal tissue improving the view of the vocal cords and facilitating advancement of an endotracheal tube into the trachea along with a laryngoscope. This series reports four cases of successful first pass intubation with the AIROD^TM.

Introduction

There are approximately 50 million intubations performed a year with 1/3 of those occurring in the USA. A multicenter registry of ED intubations, reporting data from 2002-2012, found that approximately 12% of intubations resulted in adverse intubation-related events such as death (1). In order to reduce the likelihood of adverse events it is imperative that the first attempt at endotracheal intubation is successful (2). Despite increasing adoption of expensive video laryngoscopy first-attempt intubation success rates are only 85% (1). The BEAM trial reported a 96% success rate in first-attempt intubation of a difficult airway with a bougie vs only 82% with endotracheal tube + stylet (3).

AIROD^TM was designed to aid in the advancement of an endotracheal tube past the vocal cords with the use of a laryngoscope (Figure 1).

Figure 1. Single-Use Telescopic Bougie in the closed (A) and extended (B) position with an endotracheal tube loaded at the distal end.

AIROD^TM can also improve the view of the vocal cords during intubation by displacing oropharyngeal tissue. The following case series demonstrates the usefulness of the AIROD^TM: each of the 4 intubations were successful on the first attempt and facilitated by the single-use telescopic bougie without causing any trauma. All intubations were performed by the author.

Case 1

A 70-year-old woman with severe COPD not on home oxygen presented with an oxygen saturation of 70%. She was found to have multi-lobar pneumonia predominately in the right upper and middle lobes. Despite bilevel positive airway pressure (BiPAP) therapy her hypoxia worsened, and she required intubation. Inspection of her oropharynx prior to intubation revealed very prominent 1^st incisors as well as canines that were eroded at the roots left worse than right. Multiple black, necrotic molars were noted, right worse than left, with a putrid odor. Her oxygen saturation, despite being on 15L nasal cannula, hovered in the low 90s. In anticipation of a difficult airway the AIROD^TM was prepared by extended the rods and ensuring the rods were in the locked position. A Miller 4 blade was gently inserted past the teeth and into the oropharynx. A grade 2 view (larynx plus the posterior surface of epiglottis) was obtained. This was immediately followed by gentle insertion of the AIROD^TM which was advanced just distal to the vocal cords. An 8.0 endotracheal tube was advanced down the AIROD^TM by the respiratory therapist while the AIROD^TM was held in position. As the endotracheal tube was advanced into the oropharynx, hand position was changed from holding the AIROD^TM to holding the tip of the endotracheal tube while the respiratory therapist held the distal end of the AIROD^TM. The endotracheal tube was then advanced past the vocal cords and into the trachea while the respiratory therapist removed the AIROD^TM with ease. No complications occurred. No trauma occurred to the oropharynx, vocal cords or trachea. The patient was successful ventilated and oxygen saturations improved to high 90s.

Case 2

A61-year-old man with severe schizophrenia and acute delirium had a PaO2 of 61 mmHg despite BiPAP 14/6 on 90% fio2 with a minute ventilation of 18 L/min from multi-lobar pneumonia. A Miller 4 blade was gently inserted past the teeth and into the oropharynx. A grade 1 view (whole vocal cords seen; the epiglottis is not seen at all) was obtained. The AIROD^TM was gently advanced 2 cm past the vocal cords followed by an assistant advancing a 7.5 endotracheal tube down the AIROD^TM until grasped, then the endotracheal tube was slid into the trachea while the assistant held the distal end of the AIROD^TM. The AIROD^TM was then removed intact with no evidence of airway trauma.

Case 3

A 54-year-old man with severe coronary artery disease on aspirin and Plavix with a history of a seizure disorder associated with alcohol withdrawal became unresponsive and a code blue was called. He was found to be apneic with oxygen saturation in the 50s. He was stimulated by the hospitalist and woke up. He was transferred to the ICU where he became completely unresponsive again and became apneic. He was immediately ventilated with a bag-valve mask and oxygenation improved to 100%. He then bolted up out of bed and became very combative. Propofol was given and he was laid supine and ventilated with a bag-valve mask. Inspection of his oropharynx revealed a very large tongue, some missing and multiple sharp teeth with mouth opening of only 2 fingerbreadths. There was blood and emesis in his oropharynx that was suctioned. A Miller 4 blade was inserted into the oropharynx but only a grade 4 view (the anterior tip of the epiglottis is seen and encroaching on the view of vocal cords obstructing <50% of view) could be obtained. The AIROD^TM was inserted into the oropharynx in the fully extended and locked position and the proximal tip was used to gently lift the epiglottis exposing the vocal cords and improving the view to a grade 2. AIROD^TM was advanced 2 cm past the vocal cords and an assistant advanced an 8.0 endotracheal tube down the AIROD^TM until it was grasped, and the endotracheal tube was advanced successfully past the vocal cords while the assistant held the distal end of the AIROD^TM. The AIROD^TM was removed intact without any oropharyngeal or vocal cord trauma.

Case 4

A 48-year-old obese who was an alcoholic and a smoker was critically ill with an admission albumin of 0.9 and lactic acid of 9 with multiorgan system failure from an intra-abdominal abscess with septic shock on 15 mcg/min of epinephrine and 25 mcg/min of Levophed. He was obtunded and in acute respiratory failure. The AIROD^TM was pre-loaded with an 8.0 endotracheal tube onto the distal end of the AIROD^TM prior to providing sedation with Etomidate and bag-valve mask ventilation in anticipation of a difficult airway: full beard, mouth opening 2 cm, large tongue, collapse of the walls of the oropharynx as well as false cords. Using a Miller 4 blade a grade 2 view was obtained and the AIROD^TM was advanced 1 cm past the vocal cords followed by the endotracheal tube while an assistant held the distal end. There was no significant desaturation or trauma to the vocal cords or oropharynx. Pre-loading the AIROD^TM with the endotracheal tube improved the speed and autonomy of the intubation.

Discussion

AIROD^TM is a single-use telescopic endotracheal intubation bougie. It is rigid, made of stainless steel and sterilized. It telescopes to two feet and has a specialized 20-degree angled tip. Once expanded it locks so it cannot be retracted. An endotracheal tube 7.0 or greater can be advanced over the telescoping bougie for smooth placement in the adult trachea.

AIROD^TM is non-malleable and can gently displace oropharyngeal tissue, it does not sag and pull like plastic bougies, the unique locking mechanism prevents collapse and the square handle improves dexterity as well as spatial awareness of the proximal tip.

AIROD^TM telescopes open allowing for storage in small spaces such as a pocket or a crash cart without damaging its integrity like so many bougies that are ruined when bent for storage. Because of its small size, it can be stored in a myriad of places and easily accessed by emergency personnel in the field, emergency department, intensive care unit and operating room.

AIROD^TM can be used with multiple different varieties of laryngoscopes. My preference is a Miller 4 laryngoscope because of the ability to lift the epiglottis and visualize the vocal cords especially in patients with a large tongue, limited mouth opening and decreased neck mobility. The AIROD^TM can be slid along the length of the laryngoscope blade if needed to overcome the force of oropharyngeal tissue. Once the AIROD^TM is advanced a few centimeters past the vocal cords the rigidity of the AIROD^TM allows advancement of the endotracheal tube with ease because it can withstand the forces applied by the oropharyngeal tissue without significant bending. I have also used a Macintosh laryngoscope with the AIROD^TM which allows for displacement of the tongue and oropharyngeal tissue but placement into the vallecula above the epiglottis can limit exposure to the vocal cords. The AIROD^TM can overcome the limitation of the Macintosh laryngoscope by directly lifting the epiglottis, exposing the vocal cords then the AIROD^TM can be gently slid along the posterior surface of the epiglottis past the vocal cords followed by advancement of an endotracheal tube for successful intubation. Because the AIROD^TM is made of steel, similar to the Gliderite stylet used with the Glidescope as well as laryngoscopes and rigid bronchoscopes, it is possible that if used incorrectly trauma to the oropharynx as well as the trachea may occur, and caution is advised.

The cost of the AIRODTM is similar to the Glidescope’s disposable covers that are used with each intubation. Because of the loss of direct sight and acute angles involved in the process of advancing an introducer during intubation with the Glidescope I do not recommend using the AIRODTM with the Glidescope. The AIRODTM was designed only to be used with adults.

Conclusion

AIROD^TM is a sterile single-use telescopic bougie that is used along with a laryngoscope when performing endotracheal intubation. Because of its small size it is easily stored in a pocket, helicopter, ambulance, crash cart, operating room, emergency department, intubation box and in the intensive care unit. Its rigidity helps displace oropharyngeal tissue improving the view of the vocal cords and it facilitates advancement of an endotracheal tube. It can also be used in the closed position as a stylet making it an ideal instrument for first-attempt intubation along with a laryngoscope.

Conflict of Interest Disclosures

The author Evan Denis Schmitz, MD is the inventor of the AIROD^TM.

References

1. Brown CA 3rd, Bair AE, Pallin DJ, Walls RM; NEAR III Investigators. Techniques, success, and adverse events of emergency department adult intubations. Ann Emerg Med. 2015 Apr;65(4):363-70. [CrossRef] [PubMed]
2. Sakles JC, Chiu S, Mosier J, Walker C, Stolz U. The importance of first pass success when performing orotracheal intubation in the emergency department. Acad Emerg Med. 2013 Jan;20(1):71-8. [CrossRef] [PubMed]
3. Driver BE, Prekker ME, Klein LR, Reardon RF, Miner JR, Fagerstrom ET, Cleghorn MR, McGill JW, Cole JB. Effect of use of a bougie vs endotracheal tube and stylet on first-attempt intubation success among patients with difficult airways undergoing emergency intubation: a randomized clinical trial. JAMA. 2018 Jun 5;319(21):2179-89. [CrossRef] [PubMed]

Cite as: Schmitz ED. Single-use telescopic bougie: case series. Southwest J Pulm Crit Care. 2020;20(2):64-8. doi: https://doi.org/10.13175/swjpcc005-20 PDF 

Editor's Note: On April 19, 2020 Dr. Schmitz has submitted a video showing a 6 second intubation using the AIROD and a mannequin which is below.

Left Ventricular Assist Devices: A Brief Overview

Bhargavi Gali MD

Department of Anesthesiology and Perioperative Medicine

Division of Critical Care Medicine

Mayo Clinic Minnesota

Rochester, MN, USA

Introduction

Second and third generation left ventricular assist devices (LVAD) have been increasingly utilized as both a bridge to transplantation and as destination therapy (in patients who are not considered transplant candidates) for advanced heart failure. Currently approximately 2500 LVADs are implanted yearly, with an estimated one year survival of >80% (1). Almost half of these patients undergo implantation as destination therapy. A recent systematic review and meta-analysis found no difference in one-year mortality between patients undergoing heart transplantation in comparison with patients undergoing LVAD placement (2).

Early LVADs were pulsatile pumps, but had multiple limitations including duration of device function, and requirement for a large external lead that increased risk of infection. Currently utilized second and third generation devices are continuous flow (first generation were pulsatile flow). Second generation devices have axial pumps (HeartMate II®). The third generation LVADs ((HeartMate III®), HVAD®) are also continuous flow, with centrifugal pumps, which are thought to decrease possibility of thrombus formation and increase pump duration in comparison to the second generation axial pumps. It is also felt that a lack of mechanical bearings contributes to this effect.

LVADs support circulation by either replacing or supplementing cardiac output. Blood is drained from the left ventricle with inflow cannula in the left ventricular apex to the pump, and blood is returned to the ascending aorta via the outflow cannula (3) (Figure 1).

Figure 1. Third generation Left Ventricular Assist Device. Heartware System ™. Continuous flow left ventricular assist device (LVAD) configuration. One of the third generation LVADs is the HeartWare System. With this device the inflow cannula is integrated into the pump. The pump is attached to the heart in the pericardial space, with the outflow cannula in the aorta. A driveline connects the device to the control unit. This control unit is attached to the two batteries. (Figure used with permission from Medtronic).

The device assists the left ventricle by the action of the axial (second generation) or centrifugal (third generation) pump that rotates at a very high speed and ejects the blood into the aorta via the outflow cannula. A tunneled driveline connects the pump to the external controller that operates the pump function. The controller connects to the power source via two cables, which can be battery or module-powered.

LVADs offload volume from the left ventricle, and decrease left ventricular work. Pulmonary pressures and the trans pulmonary gradients are also decreased by the reduced volume in the left ventricle (4). End organ perfusion is improved secondary to enhanced arterial blood pressure and micro perfusion.

There are four main parameters of pump function:

• Pump speed: the speed at which the LVAD rotors spin, and is programmed. Measured in RPM.
• Pump power: the wattage needed to maintain speed and flow, which is the energy needed to run the pump. Measured in Watts.
• Pump flow: estimate of the cardiac output, which is the blood returned to the ascending aorta, and is based on pump speed and power. Measure in L/min
• Pulsatility index (PI): a calculated value that indicates assistance the pump provides, in relation to intrinsic left ventricular A higher number indicates higher left ventricular contribution to pulsatile flow.

The cardiac output of currently utilized LVADs is directly related to pump speed and inversely related to the pressure gradient across the pump. As the pump speed is fixed, right ventricular failure can decrease the volume of blood transmitted to the pump and decrease LVAD flow (3, 4). With right ventricular failure, inotropic support may be needed to improve the LVAD pump flow. High afterload, such as may be seen with an increase in systemic vascular resistance can decrease pump flow.

Complications

Adverse events occur in more than 70% of LVAD patients in the first year (5). These complications include infections, bleeding, stroke, and LVAD thrombosis. More than 50% of patients are readmitted within the first 6 months after LVAD implantation (6).

Driveline infections are the most commonly reported LVAD infection, and are the most likely to respond to treatment (7). Pump pocket infections may require debridement plus/minus antibiotic bead placement. Bloodstream infections are less commonly reported, and more difficult to treat, and many patients are placed on chronic suppressive antibiotic therapy (7). There is a possible association between stroke and bloodstream infection, reported in some studies. Patients who were younger and had a higher body mass index were noted to have a higher incidence of LVAD infections.

Gastrointestinal bleeding is a major cause of nonsurgical bleeding, reported in almost 30% of patients after LVAD placement (1). Patients may develop acquired von Willebrand factor deficiency secondary to high shear forces in the LVAD that lead to breakdown of von Willebrand protein (6). Antithrombotic therapy is commonly instituted after LVAD implantation which also increases risk of bleeding. A high incidence of arteriovenous malformations is reported in these patients, although the etiology is not clear. Transfusion, holding antithrombotic therapy, and identifying possible sources are included in the standard approach to management.

There is a high risk of both ischemic and hemorrhagic strokes in the first year after LVAD placement (8). Surgical closure of the aortic valve and off-axis positioning of the cannulas have been suggested as altering shear forces, increasing thrombotic risk, and thus risk of stroke.  Post-surgical risks may include pump thrombosis, infections, supratherapeutic INR, and poorly controlled hypertension. Early diagnosis has led to consideration of interventions such as thrombectomy (8).

LVAD thrombosis can occur on either cannula (inflow or outflow) or the pump. Typically patients receive ongoing anticoagulation, commonly with warfarin, and antiplatelet agents, and often aspirin. Heartmate II® may have higher rate of thrombosis than HVAD or Heart Mate 3, although this is under debate (6). Thrombotic complications range in severity from asymptomatic increase in lactate dehydrogenase or plasma-free hemoglobin, to triggering of LVAD alarms, up to development of heart failure. The inflow and outflow cannulas and pump can be the site of thrombosis. Management typically involves revising the antithrombotic management. If there is no improvement or worsening, replacement of LVAD may be indicated. There is limited evidence to suggest that systemic thrombolysis may be of benefit in treating pump thrombosis, particularly in regards to the HVAD, though better data would be useful

Procedural Management

When a patient with an LVAD requires non cardiac surgery, optimal management includes having an on-site VAD technician, and close involvement of VAD cardiology and cardiac surgery in consultation. Anticoagulation will often be transitioned to heparin infusion prior to elective procedures (9). Suction events (LV wall is sucked into the inflow cannula) can occur secondary to under filled left heart, and this can become more apparent perioperatively. This can also decrease right heart contractility by moving the interventricular septum to the left, and thus decrease cardiac output. Management often involves fluid bolus. Suction events can lead to decreased flow, left ventricular damage, and ventricular arrhythmias. Hemodynamic management can be challenging with non-pulsatile flow, and placement of an arterial line can facilitate optimal management. Postoperative care in a monitored setting is beneficial in case of further volume related events and to watch for bleeding.

Emergent Complications

Arrhythmias occur in many patients after LVAD implantation. Atrial arrhythmias are reported in up to half of LVAD patients, and ventricular arrhythmias in 22-59% (10, 11).  Loss of AV synchrony can lead to decreased LV filling and subsequent RV failure. Rhythm or rate control with rapid atrial arrhythmias is necessary to decrease development of heart failure. Ventricular arrhythmias may be hemodynamically tolerated for some time secondary to the LVAD support (6).  If there is concern that the inflow cannula is touching the LV septum, as may occur with severe hypovolemia, echocardiography can help determine if volume resuscitation should be the initial step in treating ventricular arrhythmia.

If cardiac arrest occurs, the first step of cardiopulmonary resuscitation in patients with LVAD is assessment of appropriate perfusion via physical examination (12). If perfusion is poor or absent, assessment of LVAD function should take place. If the LVAD is not functioning appropriately, checking for connections and power is the next step. If unable to confirm function or restart LVAD, chest compressions are indicated by most recent guidelines from the American Heart Association. There is always concern of dislodgement of LVAD cannula or bleeding during these situations.

Conclusion

Currently implanted LVADS are continuous flow, and provide support via a parallel path from the left ventricle to the aorta. As the number of patients with LVADs increase all medical providers should have a basic understanding of the function and common complications associated with these devices. This will enhance the ability to initiate appropriate care.

References

1. Kirklin JK, Pagani FD, Kormos RL, et al. Eighth annual INTERMACS report: Special focus on framing the impact of adverse events. J Heart Lung Transplant. 2017 Oct;36(10):1080-6. [CrossRef] [PubMed]
2. Theochari CA, Michalopoulos G, Oikonomou EK, et al. Heart transplantation versus left ventricular assist devices as destination therapy or bridge to transplantation for 1-year mortality: a systematic review and meta-analysis. Annals of Cardiothoracic Surgery. 2017;7(1):3-11. [CrossRef] [PubMed]
3. Lim HS, Howell N, Ranasinghe A. The physiology of continuous-flow left ventricular assist devices. J Card Fail. 2017;23(2):169-80. [CrossRef] [PubMed]
4. Roberts SM, Hovord DG, Kodavatiganti R, Sathishkumar S. Ventricular assist devices and non-cardiac surgery. BMC Anesthesiology. 2015;15(1):185. [CrossRef] [PubMed]
5. Miller LW, Rogers JG. Evolution of left ventricular assist device therapy for advanced heart failure: a review. JAMA Cardiol. 2018 Jul 1;3(7):650-8. [CrossRef] [PubMed]
6. DeVore AD, Patel PA, Patel CB. Medical management of patients with a left ventricular assist device for the non-left ventricular assist device specialist. JACC Heart Fail. 2017 Sep;5(9):621-31. [CrossRef] [PubMed]
7. O'Horo JC, Abu Saleh OM, Stulak JM, Wilhelm MP, Baddour LM, Rizwan Sohail M. Left ventricular assist device infections: a systematic review. ASAIO J. 2018 May/Jun;64(3):287-294. [CrossRef] [PubMed]
8. Goodwin K, Kluis A, Alexy T, John R, Voeller R. Neurological complications associated with left ventricular assist device therapy. pert Rev Cardiovasc Ther. 2018 Dec;16(12):909-17. [CrossRef] [PubMed]
9. Barbara DW, Wetzel DR, Pulido JN, et al. The perioperative management of patients with left ventricular assist devices undergoing noncardiac surgery. Mayo Clinic Proceedings. 2013;88(7):674-82. [CrossRef] [PubMed]
10. Enriquez AD, Calenda B, Gandhi PU, Nair AP, Anyanwu AC, Pinney SP. Clinical impact of atrial fibrillation in patients with the heartmate ii left ventricular assist device. J Am Coll Cardiol. 2014 Nov 4;64(18):1883-90. [CrossRef] [PubMed]
11. Nakahara S, Chien C, Gelow J, et al. Ventricular arrhythmias after left ventricular assist device. Circ Arrhythm Electrophysiol. 2013 Jun;6(3):648-54. [CrossRef] [PubMed]
12. Peberdy MA, Gluck JA, Ornato JP, et al. Cardiopulmonary resuscitation in adults and children with mechanical circulatory support: a scientific statement from the American Heart Association. Circulation. 2017;135(24):e1115-e34.`[CrossRef] [PubMed]

Cite as: Gali B. Left ventricular assist devices: a brief overview. Southwest J Pulm Crit Care. 2019;19(2):68-72. doi: https://doi.org/10.13175/swjpcc039-19 PDF 

Airway Registry and Training Curriculum Improve Intubation Outcomes in the Intensive Care Unit

Joshua Malo MD¹

Cameron Hypes MD²

Bhupinder Natt MBBS¹

Elaine Cristan MD¹

Jeremy Greenberg MD¹

Katelin Morrissette MD¹

Linda Snyder MD¹

James Knepler MD¹

John Sakles MD²

Kenneth Knox MD¹

Jarrod Mosier MD²

¹ Department of Medicine, University of Arizona College of Medicine, Tucson, AZ

² Department of Emergency Medicine, University of Arizona College of Medicine, Tucson, AZ

Abstract

Background: Intubation in critically ill patients remains a highly morbid procedure, and the optimal approach is unclear. We sought to improve the safety of intubation by implementing a simulation curriculum and monitoring performance with an airway registry. 

Methods and Methods: This is a prospective, single-center observational study of all intubations performed by the medical intensive care unit (ICU) team over a five-year period. All fellows take part in a simulation curriculum to improve airway management performance and minimize complications. An airway registry form is completed immediately after each intubation to capture relevant patient, operator, and procedural data.  

Results: Over a five-year period, the medical ICU team performed 1411 intubations. From Year 1 to Year 5, there were significant increases in first-attempt success (72.6 vs. 88.0%, p<0.001), use of video laryngoscopy (72.3 vs. 93.5%, p<0.001), and use of neuromuscular blocking agents (73.5 vs. 88.4%, p<0.001). There were concurrent decreases in rates of desaturation (25.6 vs. 17.1%, p=0.01) and esophageal intubations (5 vs. 1%, p=0.009). Low rates of hypotension (8.3%) and cardiac arrest (0.6%) were also observed.

Conclusions: The safety of intubation in critically ill patients can be markedly improved through joint implementation of an airway registry and simulation curriculum.

Introduction

Airway management is one of the highest risk procedures that can be performed in the intensive care unit (ICU). Despite technologic advances in methods for performing intubation, recent studies continue to report frequent adverse events associated with tracheal intubation, and complications occur in up to 40% of procedures (1-3). Even in the absence of anatomic predictors of a difficult airway, critically ill patients are particularly vulnerable to desaturation, hemodynamic instability, and cardiac arrest due to poor physiologic reserve (4, 5). Repeated or prolonged intubation attempts exhaust any physiologic reserve these patients may have, leading to more frequent adverse outcomes (6). Thus, maximizing first attempt success without an adverse event is the goal for airway management in this high-risk population (7, 8).

Much of the clinical practice regarding airway management in the ICU has been extrapolated from studies performed during elective intubations in the operating room (4). In recent years, there has been a greater focus on management strategies and outcomes in critically ill patients in the emergency department (ED) and ICU (3, 9, 10). In 2012, we initiated a comprehensive airway management quality improvement program to measure variables related to airway management in the ICU and identify targeted opportunities for intervention to improve outcomes (11). We first established a prospectively collected registry of all intubations performed in the medical ICU. After evaluation of the first year of data, a simulation-based curriculum for the pulmonary and critical care fellows was developed with a focus on identifying high-risk features, minimizing adverse events, and maximizing first-attempt success. Lastly, research questions were evaluated periodically to identify targeted opportunities for improvement. This paper will describe the outcomes after the first 5 years of our program.

Materials and Methods

This is a prospective single-center observational study of all intubations performed in the medical ICU from January 1, 2012 to December 31, 2016. The study has been granted an exemption from full review and is approved by the University of Arizona Institutional Review Board. The primary outcome of interest was first attempt success, while secondary outcomes included adverse events, drug and device selection, and method of preoxygenation.

This study took place at a large academic medical center with 20+ bed medical ICU. A medical ICU team consisting of an attending intensivist, a pulmonary/critical care or emergency medicine/critical care fellow, and internal medicine, emergency medicine, and occasionally family medicine residents assumes primary management of all patients admitted to the medical ICU service. All patients admitted to the ICU undergoing airway management by the medical ICU team were included in the study.

We have maintained a continuous quality improvement (CQI) database for all episodes of airway management performed by our medical intensive care teams since January 1, 2012. After each intubation, the operators record data pertinent to the procedure, including difficult airway characteristics, drug and device selection, and number of attempts, using a standardized form. The study primary investigator crosschecked a report generated by the electronic health record against the database to ensure forms were completed for all intubations. Forms were reviewed for completeness and internal consistency. Inconsistent or absent data were resolved by interview of the operator. The variables captured in the form have been previously described (11) and are adjusted occasionally to evaluate new variables of interest.

Our Pulmonary and Critical Care Medicine (PCCM) and Critical Care Medicine (CCM) fellowship programs implemented an 11-month, simulation-based airway management curriculum beginning on July 1, 2013. The curriculum is designed to improve situational awareness in the peri-intubation period as well as to emphasize techniques that will optimize chances of first-attempt success while minimizing complications. The general outline for the simulations has been previously described in detail (11). Briefly, the curriculum involves clinical scenarios of varying and generally progressive complexity, each of which is meant to emphasize certain aspects of airway management. As trainees progress, the curriculum emphasizes the identification and mitigation of factors that may decrease the likelihood of first-attempt success and increase the likelihood of complications. The annual fellowship complement includes 14 Pulmonary and Critical Care Medicine fellows and 2 Critical Care Medicine fellows. All fellows participate in the curriculum, which is updated to include recent advances in airway management from the literature and analysis of our own airway registry. A debriefing session following each simulation is used to emphasize specific learning points for the approach to airway management.

Statistical Analysis

Descriptive statistics were calculated for measured variables as means and standard deviations, medians and interquartile ranges (IQR), or proportions as appropriate. Categorical variables were compared using Fisher’s exact test. Comparisons between Year 1 and Year 5 were performed using the Two-Sample Test of Proportions. Categorical variables with multiple groups, such as preoxygenation, Operator PGY, and Device were evaluated with the test for trend using the likelihood ratio test. All statistical analyses were performed with Stata Version 14 (StataCorp, College Station, TX).

Results

During the 60-month study period, there were 1411 intubations performed. The patient and operator characteristics are shown in Table 1 and Table 2, respectively.

Table 1. Patient characteristics.

^aSome DACs added over time. Limited mouth opening and secretions added after the first 8 months of data collection.

Table 2. First Operator Characteristics.

During the course of the study, there was no significant change in patient age or gender, the presence of difficult airway characteristics, starting saturation, or percentage of patients intubated after failing noninvasive positive pressure ventilation (NIPPV). There was a trend for decreased intubations resulting from failed extubation. The overall characteristics of intubation attempts are described in Table 3.

Table 3. Intubation characteristics.

There was a significant increase in the number of intubations performed by PCCM operators after the first year of the study (Year 1-5 difference +19%, p<0.001) accompanied by a decrease in intubations performed by internal medicine (Year 1-5 difference -9%, p=0.006) and emergency medicine residents (Year 1-5 difference -10%, p=0.003). Likewise, there was an increase in intubations performed by PGY 4 (Year 1-5 difference +13%, p=0.002) and PGY 6 (Year 1-5 difference +11%, p<0.001) operators with a concurrent decrease in those performed by PGY 2 (Year 1-5 difference -16%, p<0.001) and PGY 3 (Year 1-5 difference -8%, p=0.004) operators.

First-attempt success (FAS) occurred in 80.7% of intubations performed during the study period. The FAS rate increased linearly throughout the study period, with FAS of 72.6% in the first year and 88.0 % in the final year when looking at all operators (p<0.001) (Table 4, Figure 1, next page). 

There was a significant increase in the number of intubations performed by PCCM operators after the first year of the study (Year 1-5 difference +19%, p<0.001) accompanied by a decrease in intubations performed by internal medicine (Year 1-5 difference -9%, p=0.006) and emergency medicine residents (Year 1-5 difference -10%, p=0.003). Likewise, there was an increase in intubations performed by PGY 4 (Year 1-5 difference +13%, p=0.002) and PGY 6 (Year 1-5 difference +11%, p<0.001) operators with a concurrent decrease in those performed by PGY 2 (Year 1-5 difference -16%, p<0.001) and PGY 3 (Year 1-5 difference -8%, p=0.004) operators.

First-attempt success (FAS) occurred in 80.7% of intubations performed during the study period. The FAS rate increased linearly throughout the study period, with FAS of 72.6% in the first year and 88.0 % in the final year when looking at all operators (p<0.001) (Table 4, Figure 1).

Table 4. Outcomes.

Figure 1. First-attempt success and complications over time.

For patients intubated by fellows only, FAS increased from 77% to 92% over the 5-year period (p<0.001).

During the entire study period, at least one complication occurred in 28.7% of intubations. The incidence of complications decreased throughout the first 48 months but increased slightly in the final 12 months of the study, driven primarily by an increase in hypotension (Table 4, Figure 2).

Figure 2. Neuromuscular blocking agent (NMBA) use, video laryngoscopy (VL) use, and occurrence of esophageal intubations, desaturation, and hypotension over time.

There was a decrease in the rate of desaturation from the first year to the final year of the study (25.6% to 17.1%, p=0.01). Esophageal intubations also decreased significantly over this time (5% to 1%, p=0.009). Hypotension and cardiac arrest occurred in 8.3% and 0.6% of intubations, respectively, during the entire study period.

There was a trend towards decreased use of midazolam and propofol throughout the study period while the use of etomidate tended to increase, although these changes were not significant (Table 3). A neuromuscular blocking agent (NMBA) was used in 77.4% of intubations during the study period, increasing from the first year to the final year (73.5% to 88.4%, p<0.001), driven primarily by an increase in the use of rocuronium.

There was a significant transition from the use of direct laryngoscopy (DL) to video laryngoscopy (VL) over the course of the study (p<0.001). DL was chosen as the first approach in 22.0% of intubations in the first year and only 2.9% in the final year. Conversely, the use any form of VL on the first attempt increased from 72.3% of intubations in the first year to 93.5% in the final year. Flexible fiber optic intubation was used infrequently during the entire study period, being the first device used in 4.3% of intubations.

Various methods of preoxygenation were used throughout the study period with some form of preoxygenation occurring in 97.5% of intubations. From the first year to the final year of the study, the use of bag-valve-mask (BVM) ventilation tended to decrease (30% to 12.2%) with a concurrent trend in increasing use of NIPPV for preoxygenation (19.4% to 29.7%).

Discussion

Our experience demonstrates that utilization of a comprehensive approach to airway management including an ongoing simulation-based training curriculum and CQI database is associated with an improved first-attempt success rate for the intubation of critically ill patients. This was accompanied by changes in approach to airway management, with increased use of VL and NMBA on the first attempt, as well as an increased proportion of airways being managed by more experienced operators.

While some of the observed improvement in FAS may be attributed to more experienced operators managing the airway on the first attempt, the sharp increase in fellow-level operators after implementation of the curriculum may point to increased fellow confidence or increased recognition of high-risk patients. Furthermore, as adjunctive strategies such as ramp positioning (12-14) and apneic oxygenation (15, 16) have become increasingly recognized as potentially beneficial, a continuous training curriculum provides opportunities for evaluating trainees’ knowledge of these techniques and reinforcing their incorporation into airway management.

We have previously reported on the impact of a simulation-based curriculum on operator confidence, first-attempt success, and procedural complications (11). The combination of this curriculum with a CQI database has a marked effect on the approach to management of these patients. Strategies presented and employed in the curriculum have been informed by previous reports from our database. For example, after demonstrating improved first-attempt success with the use of neuromuscular blockade (17) and video laryngoscopy (18), the didactic portion of our curriculum incorporated these findings, which were rapidly used with increasing frequency in our intensive care unit. The integration of the curriculum and CQI database facilitates adoption of best practices, leading to a significant improvement of first-attempt success rate over a relatively short time span. The continued improvement over the course of five years is likely due to the incorporation of the practices above during this time.

Tools traditionally used for predicting difficulty of airway management have focused primarily on characteristics of an anatomically difficult intubation (19, 20). More recently, there has been an expanded focus on physiologic characteristics that may lead to complications and decreased success of intubation. However, currently available instruments for ICU patients, such as the MACOCHA score, continue to put heavy emphasis on anatomic factors and are not validated for the use of VL (21). We have found difficult airway characteristics associated with decreased FAS in the setting of VL and have focused efforts at minimizing their impact (22). In our population, we noted a consistent improvement in Cormack-Lehane grade and percentage of glottic opening (POGO) score, despite a high prevalence of anatomic difficult airway characteristics. We have also noted a significant decrease in desaturations, esophageal intubations, and a trend towards decreased overall complications. In comparison to other studies of intubation complications in critically ill patients, we found generally lower rates of esophageal intubation (1, 2, 6) and similar (10) or lower rates of desaturation (1, 2) (Table 5).

Table 5. Incidence of complications in the published literature.

Our rate of hypotension is fairly low relative to several other studies (2, 10, 23) despite a fairly inclusive definition (administration of fluid or phenylephrine bolus, initiation or increase of vasopressor infusion). Moreover, cardiac arrest was extremely uncommon in our population, occurring in 0.57% of intubations.

Data regarding optimal approach have been controversial, and randomized trial results do not always coincide with observational studies. Although randomized controlled trials have called into question the benefit of VL (24-27), there are several important limitations to each of these studies to consider when interpreting the comparison between DL and VL. In some, patients were excluded either directly (25) or indirectly (24, 26) for a history of a difficult intubation or anticipated difficult intubation. The use of endotracheal tubes without a stylet may have also influenced outcomes (27).

Our experience is a pragmatic example of the effect of device selection on first attempt success in that we have >1400 patients, operators with varying experience, and have no patients excluded because of potential difficulty. Thus, while randomized trials may be ideal, they are costly and time-consuming and may delay identification and implementation of best practices. The FAS rate in our cohort in its first year was similar to that observed in several of these trials but improved substantially over the 5-year period. One reason for the improved FAS in our study may be the continuous simulation-based training with a focus on video laryngoscopy as the first technique of choice for the majority of airways. In comparison to other widely cited studies of airway management in critically ill patients (1, 21), our cohort demonstrated a very low incidence of difficult airways, only 2% in the final year, despite a similar presence of difficult airway characteristics. This may be an effect of the training program suggesting that perhaps airway training with a global view of airway management focusing on increasing FAS and reducing complications is even more important than equipment considerations.

Our study has several limitations. The single-center, observational nature of this study makes it at risk of bias despite attempts to identify and control for factors that may influence the results. Data forms were completed by the operator, introducing potential for reporting bias, although attempts to minimize this were made by intermittent correlation with the medical record. Although FAS is an accepted outcome for studies evaluating intubation strategies, data regarding mortality or late morbidity were not captured. The increase in hemodynamic complications in the final year is of interest, but data regarding this complication and its consequences were limited and should be a focus of future research. Despite these limitations, the consistent improvement in FAS and low incidence of difficult airways in the final year of the study warrant serious consideration of these findings.

Conclusion

We have found that a comprehensive strategy employing a simulation-based curriculum and continuous quality improvement database was associated with significant improvements in first-attempt success at intubation in critically ill patients throughout the 5-year study period. We suggest that wider adoption of this practice could vastly improve the safety of intubation in this high-risk patient population.

References

1. Griesdale DE, Bosma TL, Kurth T, Isac G, Chittock DR. Complications of endotracheal intubation in the critically ill. Intensive Care Med. 2008;34(10):1835-42. [CrossRef] [PubMed]
2. Jaber S, Amraoui J, Lefrant JY, Arich C, Cohendy R, Landreau L, et al. Clinical practice and risk factors for immediate complications of endotracheal intubation in the intensive care unit: a prospective, multiple-center study. Crit Care Med. 2006;34(9):2355-61. [CrossRef] [PubMed]
3. Lapinsky SE. Endotracheal intubation in the ICU. Crit Care. 2015;19:258. [CrossRef] [PubMed]
4. Mort TC. The incidence and risk factors for cardiac arrest during emergency tracheal intubation: a justification for incorporating the ASA Guidelines in the remote location. J Clin Anesth. 2004;16(7):508-16. [CrossRef] [PubMed]
5. Mosier JM, Joshi R, Hypes C, Pacheco G, Valenzuela T, Sakles JC. The Physiologically Difficult Airway. West J Emerg Med. 2015;16(7):1109-17. [CrossRef] [PubMed]
6. Mort TC. Emergency tracheal intubation: complications associated with repeated laryngoscopic attempts. Anesth Analg. 2004;99(2):607-13, table of contents.  [CrossRef] [PubMed]
7. Hypes C, Sakles J, Joshi R, Greenberg J, Natt B, Malo J, et al. Failure to achieve first attempt success at intubation using video laryngoscopy is associated with increased complications. Intern Emerg Med. 2017 Dec;12(8):1235-43. [CrossRef] [PubMed]
8. Park L, Zeng I, Brainard A. Systematic review and meta-analysis of first-pass success rates in emergency department intubation: Creating a benchmark for emergency airway care. Emerg Med Australas. 2017;29(1):40-7. [CrossRef] [PubMed]
9. Simpson GD, Ross MJ, McKeown DW, Ray DC. Tracheal intubation in the critically ill: a multi-centre national study of practice and complications. Br J Anaesth. 2012;108(5):792-9. [CrossRef] [PubMed]
10. Smischney NJ, Seisa MO, Heise KJ, Busack KD, Loftsgard TO, Schroeder DR, et al. Practice of Intubation of the Critically Ill at Mayo Clinic. J Intensive Care Med. 2017:885066617691495. [CrossRef] [PubMed]
11. Mosier JM, Malo J, Sakles JC, Hypes CD, Natt B, Snyder L, et al. The impact of a comprehensive airway management training program for pulmonary and critical care medicine fellows. A three-year experience. Ann Am Thorac Soc. 2015;12(4):539-48. [CrossRef] [PubMed]
12. Khandelwal N, Khorsand S, Mitchell SH, Joffe AM. Head-Elevated Patient Positioning Decreases Complications of Emergent Tracheal Intubation in the Ward and Intensive Care Unit. Anesth Analg. 2016;122(4):1101-7. [CrossRef] [PubMed]
13. Ramkumar V, Umesh G, Philip FA. Preoxygenation with 20 masculine head-up tilt provides longer duration of non-hypoxic apnea than conventional preoxygenation in non-obese healthy adults. J Anesth. 2011;25(2):189-94. [CrossRef] [PubMed]
14. Turner JS, Ellender TJ, Okonkwo ER, Stepsis TM, Stevens AC, Sembroski EG, et al. Feasibility of upright patient positioning and intubation success rates at two academic emergency departments. Am J Emerg Med. 2017. [CrossRef] [PubMed]
15. Mosier JM, Hypes CD, Sakles JC. Understanding preoxygenation and apneic oxygenation during intubation in the critically ill. Intensive Care Med. 2017;43(2):226-8. [CrossRef] [PubMed]
16. Sakles JC, Mosier JM, Patanwala AE, Arcaris B, Dicken JM. First Pass Success Without Hypoxemia Is Increased With the Use of Apneic Oxygenation During Rapid Sequence Intubation in the Emergency Department. Acad Emerg Med. 2016;23(6):703-10. [CrossRef] [PubMed]
17. Mosier JM, Sakles JC, Stolz U, Hypes CD, Chopra H, Malo J, et al. Neuromuscular blockade improves first-attempt success for intubation in the intensive care unit. A propensity matched analysis. Ann Am Thorac Soc. 2015;12(5):734-41. [CrossRef] [PubMed]
18. Hypes CD, Stolz U, Sakles JC, Joshi RR, Natt B, Malo J, et al. Video Laryngoscopy Improves Odds of first-attempt success at intubation in the intensive care unit. A propensity-matched analysis. Ann Am Thorac Soc. 2016;13(3):382-90. [CrossRef] [PubMed]
19. Mallampati SR, Gatt SP, Gugino LD, Desai SP, Waraksa B, Freiberger D, et al. A clinical sign to predict difficult tracheal intubation: a prospective study. Can Anaesth Soc J. 1985;32(4):429-34. [CrossRef] [PubMed]
20. Wilson ME, Spiegelhalter D, Robertson JA, Lesser P. Predicting difficult intubation. Br J Anaesth. 1988;61(2):211-6. [CrossRef] [PubMed]
21. De Jong A, Molinari N, Terzi N, Mongardon N, Arnal JM, Guitton C, et al. Early identification of patients at risk for difficult intubation in the intensive care unit: development and validation of the MACOCHA score in a multicenter cohort study. Am J Respir Crit Care Med. 2013;187(8):832-9. [CrossRef] [PubMed]
22. Joshi R, Hypes CD, Greenberg J, Snyder L, Malo J, Bloom JW, et al. Difficult airway characteristics associated with first-attempt failure at intubation using video laryngoscopy in the intensive care unit. Ann Am Thorac Soc. 2017;14(3):368-75. [CrossRef] [PubMed]
23. Perbet S, De Jong A, Delmas J, Futier E, Pereira B, Jaber S, et al. Incidence of and risk factors for severe cardiovascular collapse after endotracheal intubation in the ICU: a multicenter observational study. Crit Care. 2015;19:257. [CrossRef] [PubMed]
24. Driver BE, Prekker ME, Moore JC, Schick AL, Reardon RF, Miner JR. Direct versus video laryngoscopy using the c-mac for tracheal intubation in the emergency department, a randomized controlled trial. Acad Emerg Med. 2016;23(4):433-9. [CrossRef] [PubMed]
25. Griesdale DE, Chau A, Isac G, Ayas N, Foster D, Irwin C, et al. Video-laryngoscopy versus direct laryngoscopy in critically ill patients: a pilot randomized trial. Can J Anaesth. 2012;59(11):1032-9. [CrossRef] [PubMed]
26. Janz DR, Semler MW, Lentz RJ, Matthews DT, Assad TR, Norman BC, et al. Randomized trial of video laryngoscopy for endotracheal intubation of critically ill adults. Crit Care Med. 2016;44(11):1980-7. [CrossRef] [PubMed]
27. Lascarrou JB, Boisrame-Helms J, Bailly A, Le Thuaut A, Kamel T, Mercier E, et al. Video laryngoscopy vs direct laryngoscopy on successful first-pass orotracheal intubation among ICU patients: A randomized clinical trial. JAMA. 2017;317(5):483-93. [CrossRef] [PubMed]

Cite as: Malo J, Hypes C, Natt B, Cristan E, Greenberg J, Morrissette K, Snyder L, Knepler J, Sakles J, Knox K, Mosier J. Airway registry and training curriculum improve intubation outcomes in the intensive care unit. Southwest J Pulm Crit Care. 2018;16(4):212-23. doi: https://doi.org/10.13175/swjpcc037-18 PDF 

RIGHT PLEURAL INSERTION OF A SMALL BORE FEEDING TUBE

Clement U. Singarajah

 Tyler Glenn

Richard A. Robbins

Phoenix VA Medical Center, Phoenix, AZ

Reference as: Singarajah CU, Glenn T, Robbins RA. Right pleural insertion of a small bore feeding tube. Southwest J Pulm Crit Care 2011;2:71-6. (Click here for PDF version)

Abstract

We report a case of a 56 year old man who had a feeding tube inadvertently malpositioned into the right pleural space and had approximately 600 ml of tube feedings infused. After the malposition was recognized, the patient underwent chest tube placement, followed by video assisted thoracic surgery 5 days later. He made an uneventful recovery. The case illustrates the problems with identification and treating feeding tube insertion into the lung.  

Case Presentation

History of Present Illness

A 56 year old male was transferred from another hospital where he had been admitted 9 days earlier for severe community acquired pneumonia secondary to penicillin sensitive Streptococcus pneumoniae, respiratory failure and sepsis syndrome. He had a past medical history of morbid obesity, type 2 diabetes mellitus, hepatitis C, hypertension and had received a pneumococcal vaccination 8 years earlier. His course was complicated by prolonged mechanical ventilation, hypotension resulting in oliguric acute renal failure and atrial fibrillation with a fast ventricular response requiring cardioversion. He had sufficiently improved with antibiotics, hemodialysis and supportive therapy that he was able to be transferred to our hospital. He had a prolonged but uncomplicated course in our intensive care unit (ICU). He was initially unable to be weaned from mechanical ventilation and underwent tracheostomy but was eventually able to tolerate tracheostomy collar and intermittent use of a tracheostomy tube with a speaking valve. He was noted to be intermittently confused and agitated. After 17 days in our ICU, transfer was planned to a general medical floor.  However, prior to leaving our ICU he pulled his feeding tube and another small bore feeding tube was inserted. An abdominal film was performed and he was transferred to the medical floor. After transfer he complained through the night of chest pain and shortness of breath and required increasing inspired oxygen concentrations in order to maintain adequate oxygen saturation. .

Physical Examination

Physical examination was not markedly changed from the previous day. He had a tachycardia of 110, blood pressure of 139/97, respirations of 24, temperature of 36.3 degrees C and weight of 140.6 kilograms. He was not oriented to time or place and seemed to be in moderate discomfort. Pertinent findings including a small bore feeding tube in his left nostril, a tracheotomy in place and rhonchi over both lungs. Abdomen was protuberant but soft and there was no presacral or pretibial edema.

Laboratory Findings

Pertinent laboratory findings included arterial blood gases showing a pH of 7.44, pCO2 of 32 mm Hg, and pO2 of 65.3 on a FiO2 of 0.7. Blood glucose was elevated at 275 and his white blood cell count had increased from 6000/microL on the day of transfer to the floor to 11,400/microL with a left shift.

Radiography

Initial abdominal films are show in figure 1.

Figure 1. Panel A and B are abdominal x-rays taken for feeding tube placement. Panel A shows the feeding tube below the diaphragm indicated by the arrow. Panel B, labeled at the same time and with the same acquisition number does not show the tube below the diaphragm but shows a tube apparently in the right chest. Panel C is an inverted image of Panel B.

A chest X-ray was taken on the patient’s return to the intensive care unit (Figure 2).

Figure 2. A. Chest X-ray shows feeding tube in trachea and right mainstem bronchus, looping in lower right chest and extending to upper right chest (arrows). B. Inverted image of A.

Hospital Course

Because of his high oxygen requirements and dyspnea, the patient was placed on mechanical ventilation. Bronchoscopy confirmed that the tube was in the lung. Due to concern for a pneumothorax should the tube be removed, a chest tube was placed first and directed to drain the pleural effusion. The feeding tube was removed and a follow up chest x-ray confirmed a pneumothorax that was treated with another chest tube. It was estimated that about 600 ml of feeding formula had been infused into the chest. Approximately 700 ml of milky fluid consistent with feeding was collected by the thoracostomy tube. Thoracic surgery consultation was obtained and recommended video-assisted thoracic surgery which was performed 5 days latter. A small amount of what appeared to be feeding formula was removed. He made a slow and uneventful recovery and was discharged to an extended care facility after a total duration of 43 days in our hospital.

Discussion

Malposition of feeding tubes is relatively common (1,2). Given that the tubes are small, relatively flexible and blindly inserted this is not surprising. In a series of more than 2000 insertions, Sorokin and Gottlieb (1) reported a 2.4% rate of lung insertion while de Aguilar-Nascimento and Kudsk (2) found a 3.2% incidence of lung malposition. Most malpositions occurred in the intensive care unit with 95% of the patients having an abnormal mental status and more than half with an endotracheal tube. Therefore, our patient was typical of the patient prone for feeding tube malposition.

To prevent feeding tube malposition, many hospitals insert the tubes under fluoroscopic guidance (3). Perhaps more commonly, other hospitals require radiographic confirmation before beginning feeding (1,2) . The later is the policy at our hospital, but as this case illustrates, mishaps can occur even with this safeguard.

In our case, several errors were made leading to the adverse event. Although recorded at the same time, the initial abdominal films were actually taken at different times. The patient had pulled his first feeding tube and a second tube had been inserted by the ICU nurse into the lung. The medicine house officer who read the films was not informed that two films were taken and saw the tube below the diaphragm on the first film. The house officer missed the tube in the chest on the second film. However, on this and three subsequent films, all read by separate radiologists, the tube malposition was also not identified. It can be difficult with multiple densities, from chest cardiac leads, suction tubing, intravenous tubing, etc. to identify potentially misplaced feeding tubes.

Generally, feeding tube malposition is reasonably well tolerated although aspiration and pneumothorax may result (1-3). Removal of the tube usually results in little apparent clinical harm. Our case is unusual in that an enteral feeding formula was introduced into the pleural space. Although there are previous reports of pneumothorax complication feeding tube insertion, these are relatively uncommon and we were uncertain how to proceed (4).  Eventually we decided on video assisted thoracic surgery with removal of any residual fluid. In this case the patient made an uneventful but prolonged recovery.  

When a feeding tube is in the lung, it may or may not have punctured the pleura. If it has, as was clear in this case by the course it took, (multiple loops), the chance of a pneumothorax on removal may be high. It is a matter of opinion as to whether or not in this situation; a prophylactic chest tube should be placed prior to removal of the feeding tube. In this case, this was performed as he was on mechanical ventilation. In situations where the feeding tube is clearly in a mainstem bronchus, removal is probably safe without due concern for a pneumothorax.

The errors in the formal radiology readings may be reduced by inverting the images within the radiology viewing program, and making sure that the full course of the feeding tube from oropharynx to tip is noted. In some obese patients, such as this one, an abdominal x-ray and chest x-ray may be required to do this.

References

1. Sorokin R, Gottlieb JE. Enhancing patient safety during feeding-tube insertion: a review of more than 2,000 insertions. JPEN J Parenter Enteral Nutr 2006;30:440-5.

2. de Aguilar-Nascimento JE, Kudsk KA. Clinical costs of feeding tube placement. JPEN J Parenter Enteral Nutr 2007;31:269-73.

3. Huerta G, Puri VK. Nasoenteric feeding tubes in critically ill patients (fluoroscopy versus blind). Nutrition 2000;16:264-7.

4. Wendell GD, Lenchner GS, Promisloff RA. Pneumothorax complicating small-bore feeding tube placement . Arch Intern Med 1991;151:599-602.