August 2023 Imaging Case of the Month: Chew Your Food Carefully

Michael B Gotway MD¹ and Yasmeen M Butt MD²

¹Departments of Radiology and ²Laboratory Medicine, Division of Anatomic Pathology

Mayo Clinic-Arizona

Scottsdale, Arizona USA

History of Present Illness

A 50-year-old woman presents with a history of chronic dyspnea and cough, becoming particularly problematic following COVID-19 infection 4 months prior to presentation. While she did experience significant periodic oxygen desaturations during her COVID-19 infection, she was not hospitalized for this illness. The patient also reported wheezing in the previous few weeks. 

Past Medical History, Family History and Social History

The patient’s past medical history was also notable for gastroesophageal reflux disease as well as both Coombs positive and iron deficiency anemia. She reports a history of asthma, well controlled with inhaler use.

The patient’s past surgical history included adenoidectomy, cholecystectomy, and gastric laparoscopic band placement.

Her medications included prednisone (20 mg daily), dextroamphetamine-amphetamine, furosemide, omeprazole, fluoxetine, zolpidem (Ambien), daily Bactrim, occasional Loratadine (Claritin). She also utilized an albuterol inhaler and Fluticasone-based (both Flonase and Breo Ellipta) inhalers.

The patient is a former smoker, ½ pack-per day for 26 years, having quit 11 years prior to presentation. She also reported a history of vaping (agent inhaled unclear) for 8 years, quitting 3 years earlier. She has no known allergies. She drinks alcohol socially and denied illicit drug use.

Physical Examination

The patient’s physical examination showed her temperature to be 99°F with normal pulse and respiratory rate but her blood pressure elevated at 160/90 mmHg. She was obese (263 lbs., BMI= 41). Bilateral basal rales were noted at her examination, but no other abnormal physical examination findings were detected.

Laboratory Evaluation

The patient’s room air pulse oximetry was 85%. A complete blood count showed an upper normal white blood cell count at 1.9 x10⁹/L (normal, 4.5 – 11 x10⁹/L). Her hemoglobin and hematocrit values were 10.7 gm/dL (normal, 12 – 16 gm/dL) and 37.1% (normal, 36 – 46%). The patient’s serum chemistries and liver function studies were entirely normal. The patient had an elevated anti-nuclear antibody titer at 1:320. An echocardiogram noted diastolic dysfunction but normal left ventricular contractility.

Frontal chest radiography (Figure 1) was performed.

Figure 1. Frontal chest radiography.

Which of the following statements regarding this chest radiograph is accurate? (Click on the correct answer to be directed to the second of 11 pages)

1. Frontal chest radiography shows normal findings
2. Frontal chest radiography shows marked cardiomegaly
3. Frontal chest radiography shows mediastinal lymphadenopathy
4. Frontal chest radiography shows pleural effusion
5. Frontal chest radiography shows multifocal peribronchial consolidation

Cite as: Gotway MB, Butt YM. August 2023 Imaging Case of the Month: Chew Your Food Carefully. Southwest J Pulm Crit Care Sleep. 2023;27(2):15-22. doi: https://doi.org/10.13175/swjpccs034-23 PDF

November 2022 Medical Image of the Month: COVID-19 Infection Presenting as Spontaneous Subcapsular Hematoma of the Kidney

Figure 1. Enhanced abdominal CT images in the axial (A) and coronal (B) reconstruction planes show uniform high attenuation material surrounding the right kidney but conforming to renal shape consistent with subcapsular hematoma (arrows).  Note the reactive perinephric stranding in the right retroperitoneal space.

A 57-year-old woman with pertinent medical history of hypertension presented to the emergency department with 3 days of right sided lower abdominal pain radiating to the flank, associated with nausea and nonbloody, nonbilious emesis. She reported recent travel to Florida where she visited amusement parks, but only rode small children’s rides with no experienced physical trauma. She experienced fatigue and chills 5 days prior to presentation and tested positive for SARS-CoV2 virus on admission. She had been vaccinated for COVID-19 x3 (Moderna). No other significant history nor medications were noted, and review of systems was otherwise unremarkable. 

Urinalysis demonstrated mild ketonuria (20), proteinuria (100) and moderate hematuria on urinalysis while BUN and creatinine remained stable at baseline throughout. Physical examination confirmed costovertebral angle tenderness to the right side. CT abdomen revealed an American Association for the Surgery of Trauma (AAST) grade 3 right renal subcapsular hematoma with 2.1 cm laceration and striations with a pre-existing right arterial aneurysm. Care was escalated to ICU for closer renal function monitoring; urology and nephrology were consulted for suspected ischemic nephropathy and renal compression with concern for Page (external compression) kidney . After exclusion of traumatic and known causes, interdisciplinary discussion came to the consensus of COVID-19 infection induced SRH.

Subcapsular renal hematoma (SRH) is a challenging medical condition in which hematoma formation may exert pressure on surrounding parenchyma resulting in hypoperfusion or ischemia, with overt concern for rupture with subsequent hemorrhage and hemodynamic instability. While this is a predominantly a medical condition precipitated by neoplasms, abdominal trauma or anticoagulant use, sporadic cases of SRH have been observed since the onset of the COVID-19 pandemic. Here, we present a rare case and imaging of COVID-19 infection induced SRH.

Even three years since the start of the COVID-19 pandemic, clinicians continue to unravel COVID-19’s impact on various body systems. While renal involvement is observed in the form of acute kidney injury in over 30% of hospitalized COVID-19 patients (1), SRH has rarely been documented. Retroperitoneal bleeding from various organs has occurred in COVID-19 patients, but this bleeding is often secondary to prophylactic anticoagulation to combat the suspected inflammation-induced hypercoagulable state (2-4). Seldom does retroperitoneal bleeding occur in the absence of anticoagulant use or other precipitating cause, as is seen in our patient with SRH. Tavoosian et al. (5) illustrate a similar case of an otherwise healthy, COVID-19 positive individual that developed spontaneous subcapsular renal hematoma without history of malignancy, trauma or anticoagulant use. The mechanism by which spontaneous SRH may occur in COVID-19 patients is still unclear. However, our case adds to literature another presentation of spontaneous SRH caused by COVID-19 infection with unique imaging findings and add to the growing differential for causes of SRH and the differential of abdominal pain. 

Kally Dey¹, Shil Punatar DO², Tauseef Sarguroh MD²

¹ Midwestern University Chicago College of Osteopathic Medicine, Downers Grove, IL USA

² Franciscan Health Olympia Fields, Olympia Fields, IL USA

References

1. Hirsch JS, Ng JH, Ross DW, et al. Acute kidney injury in patients hospitalized with COVID-19. Kidney Int. 2020;98(1):209-218. [CrossRef] [PubMed]
2. Patel I, Akoluk A, Douedi S, et al. Life-Threatening Psoas Hematoma due to Retroperitoneal Hemorrhage in a COVID-19 Patient on Enoxaparin Treated With Arterial Embolization: A Case Report. J Clin Med Res. 2020;12(7):458-461. [CrossRef] [PubMed]
3. ​​Cattaneo M, Bertinato EM, Birocchi S, et al. Pulmonary Embolism or Pulmonary Thrombosis in COVID-19? Is the Recommendation to Use High-Dose Heparin for Thromboprophylaxis Justified?Thromb Haemost. 2020;120(8):1230-1232. [CrossRef][PubMed]
4. Zhou F, Yu T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet. 2020 Mar 28;395(10229):1054-1062. Erratum in: Lancet. 2020 Mar 28;395(10229):1038.[CrossRef] [PubMed]
5. Tavoosian A, Ahmadi S, Aghamir SMK. Spontaneous perirenal haematoma (SPH) in a COVID-19 patient: A rare case report. Urol Case Rep. 2022 May;42:102006.[CrossRef] [PubMed]

Cite as: Dey K, Punatar S, Sarguroh T. November 2022 Medical Image of the Month: COVID-19 Infection Presenting as Spontaneous Subcapsular Hematoma of the Kidney. Southwest J Pulm Crit Care Sleep. 2022;25(4):67-68. doi: https://doi.org/10.13175/swjpccs041-22 PDF

April 2022 Medical Image of the Month: COVID Pericarditis

Figure 1. A: Pericardial enhancement on thoracic CT (red arrows). B: Thoracic CT in lung windows showing mosaic attenuation (black arrows) and bilateral pleural effusions (red arrows).

Figure 2. A: Static image of parasternal short axis on transthoracic echocardiogram showing moderate, generalized pericardial effusion with right ventricular diastolic collapse (red arrow). B. Static image of parasternal long axis on transthoracic echocardiogram again showing a moderate, generalized pericardial effusion (red arrow). Lower panel: video of echocardiogram in parasternal long axis view.

A 76-year-old patient presented with fatigue and shortness of breath after missing one session of dialysis. Past medical history included end stage renal disease on hemodialysis and atrial fibrillation on anticoagulation. Initial labs showed that she was COVID positive with mild elevation in troponin and a BNP 1200. While an inpatient, she had received a few sessions of dialysis and treatment for COVID (including dexamethasone and remdesivir). Initial echo showed an ejection fraction of 60-65% with a small generalized pericardial effusion, a thickened pericardium with calcification. A few days after admission patient was suddenly noted to be hypotensive with systolic blood pressure in the 70s and altered mental status. Repeated labs showed a D-Dimer of 17,232, leukocytosis, lactic acidosis, troponin 0.556 ng/ml and arterial blood gas with metabolic acidosis. With a worsening clinical picture, repeat imaging was obtained. CT angiography of the chest was negative for pulmonary embolism; however, it showed a large pericardial effusion with reduced size of the right ventricle more so than left, concerning for cardiac tamponade (Figure 1A). CT chest also showed moderate-to-large pleural effusions with scattered mosaic attenuation of the lung parenchyma (Figure 1B). Repeat transthoracic echocardiogram had a moderate generalized pericardial effusion with right ventricular diastolic collapse concerning for pericardial tamponade (Figure 2). Her airway was secured with endotracheal intubation and vasopressors added for hemodynamic support. Pericardiocentesis was indicated however, patient’s INR was severely elevated in the setting of anticoagulation use. Efforts were made to lower INR with FFP; however, patient had a PEA arrest the following day and expired.

COVID-19 has been classically known for its detrimental lung damage; however, it has shown to cause extrapulmonary effects as well. Cardiac injury is one phenomenon that has been seen with the fulminant inflammatory state that COVID is known to cause. With a few cases reported for COVID pericarditis, it is a possible culprit when all other causes have been ruled out. Pericardial involvement can be seen in about 20% of COVID 19 cases, with effusion found in about 5% of patients (1). Concomitant myocarditis can also be found in up to 17% of patients. Having isolated cardiac involvement with COVID is rare, with most cases presenting mainly as lung involvement in addition to other organs affected as well. Clinically, patients with pericarditis typically experience chest pain and in the setting of COVID infection, an increase in inflammatory markers. Characteristic findings of pericarditis include friction rub on auscultation, diffuse ST elevations on EKG and a potential progression to pericardial effusion on echo. When a pericardial effusion becomes large enough, it can progress to cardiac tamponade (2). Having a high clinical suspicion for tamponade is crucial in a patient who has developed respiratory distress and hypotension in the setting of recent viral pericarditis. It is a clinical diagnosis and requires rapid treatment with pericardiocentesis to prevent cardiac arrest.

Sarah Youkhana, MD¹ and Maged Tanios, MD²

St. Mary Medical Center, Long Beach, CA USA

¹Internal Medicine Resident, PGY-3

²Medical Director, Critical Care Services

References

1. Diaz-Arocutipa C, Saucedo-Chinchay J, Imazio M. Pericarditis in patients with COVID-19: a systematic review. J Cardiovasc Med (Hagerstown). 2021 Sep 1;22(9):693-700. [CrossRef] [PubMed]
2. Imazio M, Gaita F, LeWinter M. Evaluation and Treatment of Pericarditis: A Systematic Review. JAMA. 2015 Oct 13;314(14):1498-506. [CrossRef] [PubMed]

Cite as: Youkhana S, Tanios M. April 2022 Medical Image of the Month: COVID Pericarditis. Southwest J Pulm Crit Care Sleep 2022;24(4):62-3. doi: https://doi.org/10.13175/swjpccs006-22 PDF

Medical Image of the Month: COVID-19-Associated Pulmonary Aspergillosis in a Post-Liver Transplant Patient

Figure 1. Axial (A) and coronal (B) CT views before transplantation. The lung parenchyma appears normal.

Figure 2. Postoperative axial (A) and coronal (B) CT views 14 days later. Multiple consolidatory nodules with central break down seen involving both lungs, the largest 43mm x 47 mm in the lower lobe of right lung.

A previously healthy, 48-year-old woman, admitted with a working diagnosis of acute-on-chronic liver failure (Grade III) secondary to an autoimmune etiology, was found to be SARS COV-2 RTPCR positive on routine admission screening. She was initially managed with standard medical care for COVID, including steroids. She required invasive ventilation for worsening encephalopathy and when her antigen test was negative 10 days later, she underwent an urgent liver transplantation.

Her preoperative infection screen (culture of blood, bronchoalveolar lavage, urine) was negative and computerised tomography (CT) of the chest was normal (Figure 1). She was extubated on day 3 after liver transplantation. Her recovery was uneventful until the 10th postoperative day when she developed cough and oxygen desaturation. A repeat CT chest showed multiple multilobular consolidatory nodules with central breakdown involving both lung (Figure 2).  Her bronchoalveolar lavage culture grew Aspergillus fumigatus (azole sensitive) which fulfilled criteria for proven COVID-19 Associated pulmonary aspergillosis (pulmonary form) which the host criteria already met (1). Although she was aggressively managed with intravenous voriconazole and liposomal amphotericin, she subsequently succumbed to her illness.

COVID-19 infection shows a propensity to dysregulate the immune system and decreases T-cell lymphocytes. The dysfunctional immune system with a direct damage of respiratory epithelium by the viral infection facilitates superadded bacterial and fungal infections (2).  The use of corticosteroids and antiinterleukins in the therapy elevates the risk. Immunosuppression in an organ transplanted patient can complicate this further. Though patients with invasive fungal disease (IFD) are diagnosed and classified based on host factors, clinical factors and mycological evidences, CAPA essentially need not present with all the typical host and clinical elements (3). A high index of suspicion is essential for an early diagnosis of this condition.

Anandajith Kartha P¹, Zubair Umer Mohamed¹, Dinesh Balakrishnan², S Sudhindran²

Department of ¹Anaesthesiology and Critical Care, ²Gastrointestinal Surgery and Solid Organ Transplantation, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India

References

1. Koehler P, Bassetti M, Chakrabarti A, et al. Defining and managing COVID-19-associated pulmonary aspergillosis: the 2020 ECMM/ISHAM consensus criteria for research and clinical guidance. Lancet Infect Dis. 2021 Jun;21(6):e149-e162. [CrossRef] [PubMed]
2. Herold S, Becker C, Ridge KM, Budinger GR. Influenza virus-induced lung injury: pathogenesis and implications for treatment. Eur Respir J. 2015 May;45(5):1463-78. [CrossRef] [PubMed]
3. Donnelly JP, Chen SC, Kauffman CA, et al. Revision and Update of the Consensus Definitions of Invasive Fungal Disease From the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium. Clin Infect Dis. 2020 Sep 12;71(6):1367-1376. [CrossRef] [PubMed]

Cite as: P AK, Mohamed ZU, Balakrishnan D, Sudhindran S. Medical Image of the Month: COVID-19-Associated Pulmonary Aspergillosis in a Post-Liver Transplant Patient. Southwest J Pulm Crit Care. 2021;23(4):98-99. doi: https://doi.org/10.13175/swjpcc029-21 PDF 

Medical Image of the Month: Diffuse White Matter Microhemorrhages Secondary to SARS-CoV-2 (COVID-19) Infection

Figure 1.  An axial, maximal intensity projection (MIP), susceptibility weighted image (SWI) of the brain demonstrates numerous, punctate foci of susceptibility artifact in the genu (red arrow) and splenium of the corpus callosum (blue arrows). Other foci of susceptibility artifact are seen in the juxtacortical white matter (green arrows). These foci are consistent with microhemorrhages.

Clinical Scenario: A 59-year-old woman with hypothyroidism presented to the emergency room with progressive shortness of breath for 2 weeks.  Upon arrival, she was markedly hypoxic necessitating use of a non-rebreather to maintain her oxygen saturations above 88%. A chest radiograph demonstrated extensive, bilateral airspace disease. She was diagnosed with SARS-CoV-2 (COVID-19) pneumonia and started on the appropriate therapies. Approximately 48 hours into her hospitalization, she required intubation with mechanical ventilation due to her progressive hypoxemic respiratory failure.  She was intubated for approximately 5 weeks with a gradual improvement in her respiratory status, but not to the point where she was a candidate for a tracheostomy.  Despite being off sedation for an extended period, she remained unresponsive.  A CT of the head without contrast did not demonstrate any significant abnormalities.  An MRI of the brain was subsequently performed and demonstrated diffuse juxtacortical and callosal white matter microhemorrhages (Figure 1). Given her persistent encephalopathy and marked respiratory failure, her family elected to pursue comfort measures.

Discussion: In a recent retrospective analysis of brain MRI findings in patients with severe COVID-19 infections, 24% of the patients had extensive and isolated white matter microhemorrhages. White matter microhemorrhages with a predominant distribution in the juxtacortical white matter and corpus callosum are nonspecific and thought to be related to hypoxia.  Alternatively, small vessel vasculitis possibility related to a SARS-CoV-2 infection may result in this pattern of microhemorrhagic disease.  Diffuse axonal injury (DAI) is another etiology for microhemorrhagic disease distributed in the juxtacortical white matter and corpus callosum. However, DAI is secondary to a deceleration-type injury in the setting of trauma which is not present in most patients presenting with a SARS-CoV-2 infection. The prognosis of this condition remains to be determined.

Kelly Wickstrom, DO¹, Nicholas Blackstone MD², Afshin Sam MD¹, Tammer El-Aini MD¹

¹Banner University Medical Center – Tucson Campus, Department of Pulmonary and Critical Care, Tucson, AZ USA

²Banner University Medical Center – South Campus, Department of Internal Medicine, Tucson, AZ USA

References

1. Kremer S, Lersy F, de Sèze J, et al. Brain MRI Findings in Severe COVID-19: A Retrospective Observational Study. Radiology 2020: 297: E242-E251. [CrossRef] [PubMed]
2. Radmanesh A, Derman A, Lui Y et al. COVID-19-associated Diffuse Leukoencephalopathy and Microhemorrhages. Radiology. 2020 Oct;297(1):E223-E227. [CrossRef] [PubMed]

Cite as: Wickstrom K, Blackstone N, Sam A, El-Aini T. Medical Image of the Month: Diffuse White Matter Microhemorrhages Secondary to SARS-CoV-2 (COVID-19) Infection. Southwest J Pulm Crit Care. 2021;22(2):56-7. doi: https://doi.org/10.13175/swjpcc001-21 PDF

Medical Image of the Month and Brief Review: Aspiration Pneumonia in an Intubated Patient with COVID-19

 

Figure 1. Severe aspiration changes on CT. Bronchial wall thickening (white arrow) could barely be perceived elsewhere given the dense layering secretions (black arrows) in bilateral mainstem bronchi and filling the dependent segmental bronchi. Atelectatic collapse (black arrowhead) can be seen distal to the obstructed bronchi. Rounded consolidation (white arrowhead) as seen later in the course of SARS2 COVID-19.

A woman in her 60’s likely acquired COVID-19 through community transmission. When she developed respiratory distress, she came to the emergency department, was found to have abnormalities on chest x-ray and was intubated, testing positive on COVID-19 PCR. She developed worsening hypoxia over the course of one night after a fairly stable ICU course. CT was obtained and demonstrated severe aspiration changes including bronchial filling and collapse of the dependent lower lobes. Increased attention to suctioning helped with the desaturations, and she eventually recovered and was extubated. This case serves as a reminder to ensure adequate suctioning while patients are intubated to prevent aspiration, obstruction and related ventilator-associated pneumonia.

Discussion

Aspiration is a relatively common event which typically resolves with no clinical sequelae. In fact, recent studies have estimated that up to 50% of healthy adults aspirate while in their sleep (1). Pulmonary symptoms of aspiration generally only occur when there is compromise to the usual defenses that protect the lower airways (cough reflex, glottis closure, etc.) and when an inoculum is introduced which has a direct toxic effect on the lower airways, resulting in inflammation. Common predisposing conditions which can lead to aspiration include reduced consciousness (commonly seen in patients with alcohol abuse or IV drug use), dysphagia from neurologic deficits, disorders of the upper GI tract, or mechanical disruption of glottis closure due to endotracheal intubation, bronchoscopy, endoscopy, or NG feeding (2,3). Endotracheal intubation is a key risk factor in ventilator associated pneumonia (4). This brief review will focus on ventilator-associated pneumonia.

Overview and epidemiology: Ventilator-associated pneumonia is defined as new onset pneumonia at least 48 hours following intubation. Despite being frequently thought of as partially protective, the presence of an endotracheal tube may actually serve as a mechanism of transport of organisms from the oropharyngeal tract (most commonly) or GI tract (less commonly) to the lung (5,6). Recent data from 2012 to 2013 suggest that the percentage of patients on ventilator support who go on to acquire aspiration pneumonia is 9.7% (7).  Common pathogens associated with this condition include aerobic gram-negative bacilli (Escherichia coli, Klebsiella pneumoniae, Enterobacter spp, Pseudomonas aeruginosa, Acinetobacter spp) or gram-positive cocci including MRSA and Streptococcus Pneumoniae.

Prevention: Patients should be placed in the semi-recumbent position (45 degrees) and have intermittent (every 3-6 hours) or continuous subglottic drainage (8,9). Studies have found there isn’t a significant difference in clinical outcomes between intermittent and continuous drainage and that intermittent drainage may be associated with less adverse effects (10). The use of acid reducing agents should also be avoided, although sucralfate use decreased ICU-acquired pneumonia (11). Gastric volume monitoring had long been the standard of clinical practice with an aim to prevent vomiting and subsequent aspiration, however recent studies have suggested that gastric volume monitoring correlates poorly with aspiration risk and may lead to a decrease in caloric delivery (12,13).

Symptoms/Signs

• Important signs include fever, tachypnea, increased purulent secretions or hemoptysis; systemic signs including encephalopathy or sepsis may also be present (12).
• Ventilator: Reduced tidal volume, increased inspiratory pressures
• Labs: worsening hypoxemia, leukocytosis
• Imaging:
  • New or progressive infiltrates on CXR commonly with alveolar infiltrates or silhouetting of adjacent solid organs
  • Air bronchograms are common

Treatment

Empiric treatment choices should be guided by local distribution of pathogens and susceptibility of those pathogens to antimicrobials (14-16). Treatment options should also take into consideration the likelihood of MDR organisms or MRSA. In a meta-analysis of 15 studies, factors associated with an increased risk of MDR VAP were IV antibiotics in the last 90 days, >5 days of hospitalization prior to onset of symptoms, septic shock on presentation of VAP, ARDS before VAP, and renal replacement therapy prior to VAP. Risk factors for MRSA include treatment in units where >10 to 20% of S. Aureus isolates are methicillin resistant, treatment in a unit where prevalence of MRSA is not known, or prior history of MRSA infection. In the absence of risk factors for MDR or MRSA, patients with VAP should receive one agent that has activity against Pseudomonas, other gram-negative bacilli, and MSSA. Patients with risk factors for MDR or MRSA should receive two agents with activity against P. Aeruginosa and other gram-negative bacilli and one agent with activity against MRSA (15). An algorithm guiding specific regimens for treatment of VAP can be found on UpToDate’s article: Treatment of hospital-acquired and ventilator-associated pneumonia in adults (17).

Jeremy P. Head BS and Michael C. Larson MD

Department of Medical Imaging

University of Arizona

Tucson, AZ USA

References

1. Huxley EJ, Viroslav J, Gray WR, Pierce AK. Pharyngeal aspiration in normal adults and patients with depressed consciousness. Am J Med. 1978;64(4):564-568. [CrossRef] [PubMed]
2. Lo WL, Leu HB, Yang MC, Wang DH, Hsu ML. Dysphagia and risk of aspiration pneumonia: A nonrandomized, pair-matched cohort study. J Dent Sci. 2019;14(3):241-247. [CrossRef] [PubMed]
3. Mandell LA, Niederman MS. Aspiration Pneumonia. N Engl J Med. 2019;380(7):651-663. [CrossRef] [PubMed]
4. Rouzé A, Jaillette E, Nseir S. Relationship between microaspiration of gastric contents and ventilator-associated pneumonia. Ann Transl Med. 2018;6(21):428. [CrossRef] [PubMed]
5. Garrouste-Orgeas M, Chevret S, Arlet G, et al. Oropharyngeal or gastric colonization and nosocomial pneumonia in adult intensive care unit patients. A prospective study based on genomic DNA analysis. Am J Respir Crit Care Med. 1997;156(5):1647-1655. [CrossRef] [PubMed]
6. Jaillette E, Girault C, Brunin G, et al. Impact of tapered-cuff tracheal tube on microaspiration of gastric contents in intubated critically ill patients: a multicenter cluster-randomized cross-over controlled trial. Intensive Care Med. 2017;43(11):1562-1571. [CrossRef] [PubMed]
7. Metersky ML, Wang Y, Klompas M, Eckenrode S, Bakullari A, Eldridge N. Trend in Ventilator-Associated Pneumonia Rates Between 2005 and 2013. JAMA. 2016;316(22):2427-2429. [CrossRef] [PubMed]
8. Wang L, Li X, Yang Z, et al. Semi-recumbent position versus supine position for the prevention of ventilator-associated pneumonia in adults requiring mechanical ventilation. Cochrane Database Syst Rev. 2016;2016(1):CD009946. [CrossRef] [PubMed]
9. Caroff DA, Li L, Muscedere J, Klompas M. Subglottic Secretion Drainage and Objective Outcomes: A Systematic Review and Meta-Analysis. Crit Care Med. 2016;44(4):830-840. [CrossRef] [PubMed]
10. Mao Z, Gao L, Wang G, et al. Subglottic secretion suction for preventing ventilator-associated pneumonia: an updated meta-analysis and trial sequential analysis. Crit Care. 2016;20(1):353. Published 2016 Oct 28. [CrossRef] [PubMed]
11. Alquraini M, Alshamsi F, Møller MH, et al. Sucralfate versus histamine 2 receptor antagonists for stress ulcer prophylaxis in adult critically ill patients: A meta-analysis and trial sequential analysis of randomized trials. J Crit Care. 2017;40:21-30. [CrossRef] [PubMed]
12. Meduri GU. Diagnosis and differential diagnosis of ventilator-associated pneumonia. Clin Chest Med. 1995;16(1):61-93. [PubMed]
13. McClave SA, Lukan JK, Stefater JA, et al. Poor validity of residual volumes as a marker for risk of aspiration in critically ill patients. Crit Care Med. 2005;33(2):324-330. [CrossRef] [PubMed]
14. Kalil AC, Metersky ML, Klompas M, et al. Executive Summary: Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society [published correction appears in Clin Infect Dis. 2017 May 1;64(9):1298] [published correction appears in Clin Infect Dis. 2017 Oct 1;65(7):1251]. Clin Infect Dis. 2016;63(5):575-582. [CrossRef] [PubMed]
15. Beardsley JR, Williamson JC, Johnson JW, Ohl CA, Karchmer TB, Bowton DL. Using local microbiologic data to develop institution-specific guidelines for the treatment of hospital-acquired pneumonia. Chest. 2006;130(3):787-793. [CrossRef] [PubMed]
16. Jones RN. Microbial etiologies of hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia [published correction appears in Clin Infect Dis. 2010 Nov 1;51(9):1114]. Clin Infect Dis. 2010;51 Suppl 1:S81-S87. [CrossRef] [PubMed]
17. Klompas M. Treatment of hospital-acquired and ventilator-associated pneumonia in adults. UpToDate. July 31, 2020. Available at: https://www.uptodate.com/contents/treatment-of-hospital-acquired-and-ventilator-associated-pneumonia-in-adults (requires subscription).

Cite as: Head JP, Larson MC. Medical image of the month and brief review: aspiration pneumonia in an intubated patient with COVID-19. Southwest J Pulm Crit Care. 2020;21(2):35-8. doi: https://doi.org/10.13175/swjpcc040-20 PDF 

Medical Image of the Month: Viral Pneumonias

Figure 1. Pulmonary viral infection spectrum on thoracic CT scan in lung windows: A= Coronavirus NL63; B= Adenovirus; C= Influenza AH1 2009; D= COVID-19; E= Coronavirus HKU1; F= Influenza AH1 2009.

Numerous viruses, including the corona, influenza and adenoviruses can cause lower respiratory tract infection in adults (1). Viral pneumonia in adults can be classified into two clinical groups: so-called atypical pneumonia in otherwise healthy hosts and viral pneumonia in immunocompromised hosts. Until the COVID-19 pandemic, influenza virus types A and B caused most cases of viral pneumonia in immunocompetent adults. Immunocompromised hosts are susceptible to pneumonias caused by a wide variety of viruses including cytomegalovirus, herpesviruses, measles virus, and adenovirus. The CT imaging findings consist mainly of patchy or diffuse ground-glass opacity, with or without consolidation, and reticular areas of increased opacity, are variable and overlapping. The imaging findings in COVID-19 pneumonia are generally not distinctive compared to other viral pneumonias, including other coronaviruses such as SARS and MERS (2). A recent study systematically reviewed the longitudinal changes of CT findings in COVID-19 pneumonia. The results suggested that the lung abnormalities increase quickly after the onset of symptoms, peak around 6-11 days, and are followed by persistence of the findings.

Bacterial pneumonias may also take multiple forms and are sometimes difficult to radiographically separate from viral pneumonia (3). However, the presence of ground-glass opacities alone is unusual for a bacterial pulmonary infection. Rather, bacterial infections commonly present as areas of consolidation with air bronchogram formation, centrilobular nodules (often with branching configurations) and airway thickening.

Michael B. Gotway MD

Department of Radiology

Mayo Clinic Arizona

Scottsdale, AZ USA

References

1. Kim EA, Lee KS, Primack SL, et al. Viral pneumonias in adults: radiologic and pathologic findings. Radiographics. 2002 Oct;22 Spec No:S137-49. [CrossRef] [PubMed]
2. Wang Y, Dong C, Hu Y, Li C, Ren Q, Zhang X, Shi H, Zhou M. Temporal Changes of CT Findings in 90 Patients with COVID-19 Pneumonia: A Longitudinal Study. Radiology. 2020 Mar 19:200843. [CrossRef] [PubMed]
3. Panse PM, Jokerst CE, Gotway MB. May 2020 Imaging Case of the Month: Still Another Emerging Cause for Infiltrative Lung Abnormalities. Southwest J Pulm Crit Care. 2020. May 1. (in press). [CrossRef]

Cite as: Gotway MB. Medical image of the month: viral pnuemonias. Southwest J Pulm Crit Care. 2022;20(5):163-4. doi:  https://doi.org/10.13175/swjpcc028-20 PDF