Severe Accidental Hypothermia in Phoenix? Active Rewarming Using Thoracic Lavage

Michael Mozer BS¹

Guy Raz, MD²

Ryan Wyatt, MD²

Alexander Toledo, DO, PharmD²

¹University of New England College of Osteopathic Medicine

Biddeford, ME USA

²Department of Emergency Medicine

Maricopa Medical Center, Phoenix, AZ USA

Abstract

Hypothermia can progress quickly and become life threatening if left untreated. Rewarming in the severely hypothermic patient is of critical importance and is achieved with active and passive techniques. Here we present a case of a hypothermic patient with cardiac instability for whom thoracic lavage was ultimately used. We will review the treatment of hypothermia and discuss the technical aspects our approach.

Case Presentation

A 53 year-old male with a past medical history of substance abuse, chronic hepatitis C, and poorly controlled type 2 diabetes mellitus complicated by a recent hospitalization for osteomyelitis was brought to the emergency department after being found lying on a road in a shallow pool of water in the early morning hours of a rainy day in Phoenix, Arizona. The ambient temperature that night was 39 °F (3.9 °C). Emergency Medical Services (EMS) noted a decreased level of consciousness and obtained a finger stick glucose of 15 mg/dl. EMS reported a tympanic membrane temperature of 23.9 °C. En route, the patient was administered 2mg naloxone and 25g dextrose intravenously with no improvement in his mental status. On Emergency Department (ED) arrival, the patient had a GCS of 8 (Eyes 4, Verbal 1, Motor 3) and exhibited intermittent posturing. His foot wound appeared clean and without signs of infection. The initial core temperature recorded was 25.9°C via bladder thermometer, systolic blood pressure was 92/50, and heart rate fluctuated between 50 and 90 beats per minute.

After removing wet clothing, initiation of warmed saline, and placing a forced warm air blanket on the patient, he was intubated for airway protection and vasopressors were initiated. Osborn waves were evident on the initial EKG (Figure 1).

Figure 1. Initial EKG with Osborn Waves (arrows).

A warmed ventilator circuit was initiated with only 0.5 °C increase in temperature in first 30 minutes. Despite these measures, he remained hypotensive and unstable. Significant laboratory findings were a white blood cell count of 25.5 thousand (92% neutrophils), lactic acid of 7.6, potassium of 5.8, serum creatinine of 1.05, glucose of 283, INR of 1.1, and urine drug screen positive for cocaine. Given his recalcitrance to norepinephrine and risk of death secondary to fatal dysrhythmia with temperatures below 28 °C intrathoracic lavage initiated.

The right hemithorax was selected for irrigation because left-sided tube placement can induce ventricular fibrillation in a perfusing patient (1). Using standard sterile technique, two 36 French thoracostomy tubes were placed; the first in the second intercostal space along the mid-clavicular line, and the second in the 5^th intercostal space in the posterior axillary line (1-3). The tips of the thoracostomy tubes were oriented such that the anterior-superior tube was positioned near the right apex and the lateral-inferior tip was positioned low in the thoracic cavity (1,3). To maintain the temperature of the instilled fluid, a fluid warmer system (Level 1; Smiths Medical; Minneapolis, MN) was used and set to 41 °C. A Christmas tree adapter was used to connect the IV tubing to the superior thoracostomy tube, and a water seal chamber was attached to the inferior tube for passive drainage (3). Flow through the system was targeted to maintain steady passive drainage as described in the literature (1-6).

Thoracic cavity lavage with 41 °C saline was performed and the patient was transferred to the medical ICU after 3 hours in the ED. When he was transferred his core temperature was 29 °C and he remained on norepinephrine for hemodynamic instability. After 2 hours of continued rewarming in the MICU, his core temperature was 32 °C. Osborn waves evident on initial EKG were resolved (Figure 2).

Figure 2. Repeat EKG showing resolution of Osborn waves.

The patient left against medical advice from the hospital 4 days later neurologically intact and without sequela.

Discussion

Hypothermia can be clinically classified as mild, moderate or severe (7). Mild hypothermia, defined as core temperatures of 32-35 °C, presents with shivering. Amnesia, dysarthria, ataxia, tachycardia, and tachypnea can also be seen (1). Moderate hypothermia, defined as core temperatures of 28-32 °C, usually can present with or without shivering. Stupor, hypoventilation, paradoxical undressing and non-fatal arrhythmias such as atrial fibrillation and junctional bradycardia may also be seen (1). Patients with severe hypothermia, generally defined as temperatures below 28 °C, can present with coma, areflexia, pulmonary edema, bradycardia, and hypotension (1). There is a significant risk of fatal cardiac dysrhythmias without rapid therapeutic rewarming (1,7,8).

Rewarming in the hypothermic patient is of critical importance and is achieved with passive and/or active techniques. Attempts to limit heat loss are often unsuccessful, especially in the absence of a normal shiver response. It however remains as the first line treatment for hypothermia (8-10). Passive rewarming is attempted by the removal of cold/wet clothing and keeping the patient covered (8-10). Active external rewarming (AER) is the next line of treatment and consist of the use of externally rewarming devices such as warmed blankets, warm environment, forced air warming (Bair Hugger; 3M; Maplewood, MN) or warm hot water bladders placed in the groin and axilla (1,7-10). Active Internal Rewarming (AIR) techniques can be used to achieve more rapid increases in core temperature and are primarily utilized in cases of cardiac instability or if AER is unsuccessful (8). When available, the method of choice for active internal rewarming (AIR) is cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation (ECMO) as they can achieve the fastest increase in core temperature (9 °C/hr and 6 °C/hr respectively) and provide cardiovascular support (1,8,11,12). Several techniques are described in the literature that can be considered if CPB or ECMO are unavailable. These include esophageal warming devices, endovascular catheters, hemodialysis, and endocavitary lavage (1,2,4-6,13-15). While no randomized controlled trials exist, several case reports and reviews have tried to compare various techniques. These sources to do not seem to favor any particular technique over another but rather reports the rates of temperature rise (1-3,5-7,13-15). Classically, lavage techniques are attempted in the thoracic cavity, the peritoneum, the bladder, the stomach, the esophagus, or the colon. These techniques are generally coupled with warm IV fluids and warming air through the ventilator to limit loss of body heat to iatrogenic procedures during the rewarming attempt (1,7). Thoracic lavage is effective with a reported rewarming rates of 3-6 °C/hr and with excellent outcomes in case reports (1,2,4-6). Here we present a case of a hypothermic patient with cardiac instability where thoracic lavage is used and discuss the technical aspects of this approach.

Our case demonstrates the efficacy of utilizing thoracic cavity lavage for rapid rewarming in patients with severe hypothermia with a pulse and at high risk of fatal cardiac arrhythmia. In multiple case reports, thoracic lavage has been used successfully in hypothermic patients who suffered complete cardiopulmonary collapse requiring CPR (2,4,5). Although warm thoracic lavage is not the treatment of choice in these circumstances, in a facility not equipped with ECMO or CPB and a patient too unstable to transfer, it seemed to us to be the best technique. Gastric, colonic, and bladder lavage offer very minimal heat transfer due to limitations in surface area (2).

Hemodialysis would have required for us to call in a technician and would have required approval by a nephrologist at our institution. Available central venous rewarming catheters require bypass of a failsafe mechanism that does not allow rewarming to be initiated below 30 °C (1). Peritoneal lavage was a plausible choice but does not directly warm the mediastinum (2). While an open mediastinal technique has been used, we did not feel it was appropriate in a patient with a concurrent pulse (1,3). Thoracic lavage is therefore an effective alternative that should be used in cases where CPB and ECMO are unavailable especially in a patient that is hemodynamically unstable and may not survive transfer. The equipment is readily available to any Emergency Medicine or Critical Care physician. In addition, this case exemplifies the positive outcomes that are associated with rapid rewarming in the hypothermic patient with a pulse. We believe our case demonstrates the efficacy of this technique for myocardial protection from hemodynamic collapse, a topic which has not been adequately studied in the literature.

References

1. Brown DJ, Danzl DF. Accidental hypothermia. In: Auerbach PS, ed. Wilderness Medicine. 7th ed. St. Louis: Mosby Inc.; 2017:135-62.
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10. Zafren K, Giesbrecht GG, Danzl DF, et al. Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia: 2014 update. Wilderness Environ Med. 2014 Dec;25(4 Suppl):S66-85. [CrossRef] [PubMed]
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12. Saczkowski RS, Brown DJA, Abu-Laban RB, Fradet G, Schulze CJ, Kuzak ND. Prediction and risk stratification of survival in accidental hypothermia requiring extracorporeal life support: An individual patient data meta-analysis. Resuscitation. 2018;127:51-7.[CrossRef] [PubMed]
13. Primozic KK, Svensek F, Markota A, Sinkovic A. Rewarming after severe accidental hypothermia using the esophageal heat transfer device: a case report. Ther Hypothermia Temp Manag. 2018 Mar;8(1):62-4. [CrossRef] [PubMed]
14. Murakami T, Yoshida T, Kurokochi A, et al. Accidental hypothermia treated by hemodialysis in the acute phase: three case reports and a review of the literature. Intern Med. 2019 Jun 7. [CrossRef]
15. Klein LR, Huelster J, Adil U, et al. Endovascular rewarming in the emergency department for moderate to severe accidental hypothermia. Am J Emerg Med. 2017 Nov;35(11):1624-9. [CrossRef] [PubMed]

Cite as: Mozer M, Raz G, Wyatt R, Toledo A. Severe accidental hypothermia in Phoenix? Active rewarming using thoracic lavage. Southwest J Pulm Crit Care. 2019;19(2):79-83. doi: https://doi.org/10.13175/swjpcc038-19 PDF 

Refractory Cardiogenic Shock

Bhupinder Natt, MD (bnatt@deptofmed.arizona.edu)

Tauseef Afaq Siddiqi, MD (tsiddiqi@deptofmed.arizona.edu)

Jarrod Mosier, MD (jmosier@aemrc.arizona.edu)

Yuval Raz, MD (yraz@deptofmed.arizona.edu)

Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, University of Arizona, Tucson, AZ

Abstract

We present a case of refractory cardiogenic shock secondary to myxedema crises that was treated successfully with thyroid hormone replacement.

Case Presentation

History of Present Illness

A 62-year-old woman with past medical history significant only for hypothyroidism was seen in the emergency department (ED) after a fall at home. On further evaluation, the patient’s husband reported history consistent with deteriorating mental function as evident by speech alteration, inability to operate home appliances like the coffeemaker and gradually worsening generalized weakness. She was recently seen at an outside hospital the week previous to this admission and given a prescription for furosemide for pedal edema.

ED evaluation showed her to be lethargic, disoriented with progressively deteriorating mentation, with hypothermia and bradycardia. Her progressive decline in mentation led to endotracheal intubation for airway protection. The patient was started on vasopressors due to post-intubation hypotension and transferred to the Medical Intensive Care Unit (MICU).

Vitals and Physical Exam

Vitals upon presentation to ED: Temperature 29^o Celsius; Heart Rate 42 bpm; Blood Pressuren107/79 mm Hg; Respiratory Rate 14/min; SpO2 97 % on Room Air.

Vitals upon arrival in MICU: Temperature of 29^o Celsius; Heart Rate 43 bpm; Blood Pressure 111/57 mmHg; Respiratory Rate of 10/min; SpO2 100% on mechanical ventilation;

Neurologically, she was sedated with no obvious localizing signs. Skin exam revealed a sutured scalp lesion and scattered abrasion on arms. Cardiopulmonary exam was significant only for bradycardia, which was determined to be sinus rhythm by the electrocardiogram (EKG). Other system examination was significant only for 2+ non-pitting edema of upper and lower extremities.

Laboratory and Radiology Data

CBC: White Cell Count 8.4x1000/microL; Hemoglobin 9.5 g/dL; MCV 100 fL; Platelets 82x1000/microL.

Electrolytes and Metabolic Panel: Sodium 134 mMol/L; Potassium 4.2 mMol/L; Chloride 97 mMol/L; Bicarbonate 26 mMol/L; Urea Nitrogen 38 mg/dL; Creatinine 0.9 mg/dL. Glucose 78 mg/dL; Calcium 9.6 mg/dL.

Total Protein 6.3 g/dL; Albumin 3.7 g/dL; Bilirubin 0.7 mg/dL; Alkaline Phosphate 104 IU/L; ALT 72 IU/L; AST 158 IU/L; TSH 36.1 uIU/mL; Thyroxine 0.8 ng/dL; Free T3 1.2 pg/mL (Normal 2.4-4.2 pg/mL); Cortisol 20.3 mcg/dL.

ABG: pH 7.52; PaCO2 34; PaO2 166; HCO3 28; SaO2 97.6 % on 50% FiO2.

Urine Analysis: Negative.

Urine Drug Screen: Negative.

Chest X-Ray: Emphysematous changes with no acute cardiopulmonary process.

Non-contrast CT of the head and cervical spine: Unremarkable except scalp hematoma.

EKG at Presentation

MICU Course

After initial stabilization of blood pressure in ED; receiving four liters of intravenous fluids; and norepinephrine infusion at increasing doses, she was transferred to MICU. She required two more liters of crystalloids, vasopressin and increasing doses of norepinephrine, epinephrine, phenylephrine and dobutamine infusions. Corticosteroid was added for refractory shock. She also received first dose of broad-spectrum antimicrobials in ED.

Two hours after arrival to the MICU, seven hours post presentation to the ED; a Swan-Ganz pulmonary artery catheter was placed. The values obtained from the Swan-Ganz catheter are reported in table 1. 

These values were obtained seven hours into admission, while the patient was being actively rewarmed, treated with a total of six liters (L) of crystalloid solutions and on norepinephrine at 13 mcg/min and dobutamine at 5 mcg/kg/min.

The patient remained hypotensive and sequentially, within hours, multiple vasopressors and inotropic agents were required. Table 2 reports the vitals and values off the Swan-Ganz catheter 12 hours after initial placement, when the patient is being actively rewarmed, treated for close to 18 hours and while receiving intravenous epinephrine at 3 mcg/min, norepinephrine at 30 mcg/min, vasopressin a 0.03 units/min, phenylephrine at 150 mcg/min and dobutamine at 20 mcg/min. 

A formal 2-D echocardiogram was obtained which showed a global left ventricular dysfunction and hypokinesis with reduced ejection fraction of 35% and mildly reduced right ventricular dysfunction. No major valvular or pericardial pathology was noticed. Given the patient’s history and clinical features of hypothyroidism, a diagnosis of myxedema coma was made and treatment started with levothyroxine 125 mcg a day intravenously. Corticosteroids were discontinued due to concern of blockage of peripheral conversion of T4 to T3. T3 was unavailable in our city initially but was subsequently obtained and prescribed to our patient at 25 mcg of liothyronine three times a day. She responded very well to the treatment and was successfully weaned off all vasopressor support, liberated from mechanical ventilation on the fourth day and transferred out of the MICU on day five of admission. Limited repeat echocardiogram prior to transfer out of the MICU showed an ejection fraction of 65%.

Cultures, lumbar puncture and all imaging including brain MRI obtained during admission and MICU stay remained negative. A potential precipitating factor was not found and all empiric treatments were gradually withdrawn prior to the transfer out of MICU.

Retrospective history taking revealed patients’ non-compliance with levothyroxine treatment for the past 2 years. She had been given a dose of levothyroxine while she was admitted at the outside hospital the week previously leading to her relatively normal T4 level, suggesting inhibited peripheral conversion to T3 and thus the limited effect of intravenous levothyroxine initially. Surprisingly, despite the ordeal, she continued to refuse to take the medication once extubated and transferred to Medicine.

Discussion

A myxedema crisis is an extreme and life-threatening form of hypothyroidism that requires prompt diagnosis and treatment. Mortality rate has been reported as high as 60% despite appropriate diagnosis and management (1,2). Infections and discontinuation of thyroid supplements are the major precipitating factors. Other precipitants include hypothermia, gastrointestinal bleeding, congestive heart failure, cerebrovascular accident, metabolic disturbance and sedative drugs (3).

Myxedema crises manifests by involving multiple organ systems. Hypothermia can be profound and is usually the first sign of myxedema coma. Neuropsychiatric manifestations include confusion, lethargy, coma, psychosis (myxedema madness), and seizures. Respiratory depression is common likely due to depressed hypoxic and hypercapnic respiratory drive. Edema (myxedema) involving upper airways contributes to acute respiratory failure. Reduced intestinal motility leads to constipation, paralytic ileus and mega colon. Urine retention from bladder atony can be seen. Reduced glomerular filtration and reduced water excretion leads to hyponatremia, a consistent finding in myxedema crises.

Cardiovascular effects of myxedema crises include conduction abnormalities, reduced contractility, cardiomegaly and pericardial effusion. Sinus bradycardia, low voltage complexes, bundle branch blocks, complete heart blocks, and nonspecific ST-T changes in electrocardiogram have been reported. Prolonged QT interval and polymorphic ventricular tachycardia has been described as well (4). Depressed cardiac contractility leads to low stroke volume and cardiac output. Animal studies have documented that hypothyroidism leads to cardiomegaly from cardiac atrophy, impaired myocardial blood flow and loss of arterioles resulting in severe systolic dysfunction (5).

These cardiogenic effects of hypothyroid state leading to depressed ionotropy and chronotropy with compensatory vasoconstriction are believed to be a result of low intracellular T3. The hypothyroid heart attempts to perform by better coupling of ATP to contractile events until a precipitating event disrupts this fine balance (6). This resultant de-compensation leads to hypotension and cardiogenic shock that may not respond to vasopressors alone until thyroid hormone replacement is given.

Treatment usually involves intensive care admission with cardiopulmonary support, aggressive fluid and electrolyte management, treatment of underlying and precipitating factors and thyroid hormone replacement. Intravenous T4 is the most commonly used preparation as intestinal absorption may not be reliable. In severe illness, the conversion of T4 to T3 by 5’-monodeiodinase is impaired. Intravenous T3 preparation should be used. Improved cardiac function is reported in 24 hours when T3 replacement is used and it may take up to a week to notice beneficial effects with T4 replacement alone (7).

References

1. Mathew V, Misgar RA, Ghosh S, Mukhopadhyay P, Roychowdhury P, Pandit K, Mukhopadhyay S, Chowdhury S. Myxedema Coma: a new look into an old crisis. J Thyroid Res. 2011:493462.[CrossRef] [PubMed]
2. Wartofsky L, Myxedema Coma, Endocrinol Metab Clin N Am. 2006; 35(4): 687-98. [CrossRef][PubMed]
3. Brent GA, Davies TF. Hypothyroidism and thyroiditis. In: Melmed S, Polonsky KS, Reed P, Kronenberg HM, eds. Williams Textbook of Endocrinology. Philadelphia, PA: WB Saunders, 2008.
4. Schenck JB, Rizvi AA, Lin T. Severe primary hypothyroidism manifesting with torsades de pointes. Am J Med Sci. 2006 Mar; 331(3): 154-6. [CrossRef] [PubMed] 
5. Tang YD, Kuzman JA, Said S, Anderson BE, Wang X, Gerdes AM. Low thyroid function leads to cardiac atrophy with chamber dilatation, impaired myocardial blood flow, loss of arterioles, and severe systolic dysfunction. Circulation. 2005;112(20):3122-30. [CrossRef] [PubMed]
6. W. M. Wiersinga. Hypothyroidism and myxedema coma. In: Jameson JL, Legroot LJ, eds. Endocrinology: Adult and Pediatric. Philadelphia, PA: Saunders Elseiever, 6th edition, 2010:1607-22.
7. MacKerrow SD, Osborn LA, Levy H, Eaton RP, Economou P. Myxedema associated cardiogenic shock treated with intravenous triiodothyronine. Ann Int Med. 1992;117:1014-5. [CrossRef][PubMed] 

Reference as: Natt B, Siddiqi TA, Mosier J, Raz Y. Refractory cardiogenic shock. Southwest J Pulm Crit Care. 2013;7(4):246-50. doi: http://dx.doi.org/10.13175/swjpcc098-13 PDF