DOI: https://doi.org/10.21203/rs.3.rs-41878/v1
Background: There is an increasing amount of literature describing the pathogenesis of coronavirus disease 2019 (COVID-19) pneumonia and its associated complications. Historically, a small pneumothorax has been shown to be successfully treated without chest tube insertion, but this management has yet to be proven in COVID-19 pneumonia patients. In addition, pneumothorax in an intubated patient with high positive end-expiratory pressure (PEEP) provides additional uncertainty with pursuing non-operative management.
Case Presentation: In this series we report four cases of patients with respiratory distress who tested positive for COVID-19 via nasopharyngeal swab and developed ventilator-induced pneumothoraces which were successfully managed with observation alone.
Conclusions: Management of patients with COVID-19 pneumonia on positive pressure ventilation who develop small stable pneumothoraces can be safely observed without chest tube insertion.
COVID-19 pneumonia may cause cystic features of lung parenchyma which can resolve or progress to larger blebs.1,2 This can place patients at risk for rupture resulting in mediastinal and subcutaneous emphysema or secondary spontaneous pneumothorax. Many are intubated and placed on low tidal volume and high PEEP ventilation therapy which further increases concern for rupture. For critically ill patients on positive pressure ventilation, although controversial, it is currently recommended to place a tube thoracostomy when a pneumothorax is observed.3 Due to limited knowledge of lung histopathology with COVID-19, it is unknown how well the diseased lung tissue will spontaneously heal and re-expand without intervention. For moderate to large pneumothorax and prolonged air leak, there have been reports of successful treatment with video-assisted thoracoscopic surgery and wedge resection.4 There have also been explanations on how to contain viral dissemination by using bespoke viral filtration systems to limit contamination.5 However, for a small pneumothorax in a stable patient, chest tube placement may be second line to watchful waiting. We present four cases of pneumothorax in COVID-19 positive patients who were managed without chest tube placement despite being on positive pressure ventilation.
Case 1
A 48-year-old male with hypertension and hyperlipidemia without a history of cigarette smoking presented to the emergency (ED) with one week of a worsening dry cough associated with chest pain, headaches, myalgia, shortness of breath, and subjective fevers. A chest computed tomography (CT) showed bilateral ground glass opacities (Fig. 1A). Laboratory workup showed white blood cell count of 9,000 /µL, c-reactive protein 8.66, creatinine 1.32 mg/dL, and procalcitonin 0.14 mg/dL. The next day he was confirmed COVID positive. He soon developed acute respiratory insufficiency, required intubation, and was transferred to the intensive care unit. Ventilatory settings were PEEP 16 cm H2O, tidal volume (VT) 6 mL/kg, and target plateau pressure 30–55 cm H2O. His FiO2 was weaned to 40% and on hospital day 4 his chest x-ray showed extensive subcutaneous emphysema and bilateral tiny apical pneumothoraces (Fig. 1B). He later received a tracheostomy and has since been weaned from the ventilator. His tracheostomy tube has been downsized and over 3 months later chest x-rays showed no pneumothorax.
Case 2
A 76-year-old male presented to the ED with shortness of breath and excessive dry coughing. The patient had tested positive for COVID-19 three days prior but was sent home to recover. Over the course of those three days, the patient got progressively worse, with decreased O2 saturations and increased work of breathing. He also began to have worsening cough and persistent fevers while at home. Upon return to the ED, he was severely hypoxic with increased work of breathing and required intubation within 36 hours of presentation. Treatment was initiated with azithromycin, hydroxychloroquine, zinc, tocilizumab, and dexamethasone for his COVID-19 infection. His hospital course was complicated by septic shock, acute respiratory distress syndrome (ARDS), volume overload, and uncontrolled diabetes. The patient had been intubated and on ventilator support for 21 days when a chest x-ray revealed bilateral pneumothoraces, which were confirmed with a chest CT, along with pneumomediastinum (Fig. 2). The patient was transferred to a hospital where thoracic surgery was available. The patient’s clinical status remained critical and follow up chest x-rays showed resolution of pneumothoraces. On hospital day 31 chest x-ray continued to show no pneumothorax, however the patient passed away from hypoxic respiratory failure later that day.
Case 3
This is a 68-year-old male who was exposed to a family member who was COVID-19 positive. He began complaining of fevers, cough and dizziness several days prior to presentation to the ED. He was hospitalized for workup of pre-syncope and was confirmed COVID-19 positive. His respiratory status declined and on hospital day 3 he was transferred to the ICU where he was intubated. Over the next 21 days the patient failed two extubation attempts secondary to hypercapnia and hypoxia. In addition, one failed extubation led to an aspiration event leading to superimposed aspiration pneumonia. A right internal jugular dialysis catheter was replaced on hospital day 28 with no pneumothorax seen on post-procedure chest x-ray. Three days later a small right-sided pneumothorax was noted on chest x-ray (Fig. 3A) and the thoracic surgery service was consulted. Due to a stable clinical status, expectant management was pursued. A repeat x-ray 8 hours later showed the pneumothorax was stable. Three days later the patient decompensated from a respiratory standpoint and a chest x-ray that morning showed resolution of the pneumothorax (Fig. 3B). An hour later the patient died from respiratory failure secondary to ARDS.
Case 4
This patient is a 76-year-old female who presented to the emergency department with altered mental status, hypotension, suspected GI bleed with severe anemia, and sepsis of unknown origin. She was positive for COVID-19 pneumonia and became acutely hypoxic on hospital day 3, requiring emergent intubation. The hospital course was complicated by septic shock leading to multi organ system failure. Throughout her hospital course she continued to require vasopressor support and was ventilator dependent. Her ventilator support requirements remained stable and approximately three weeks into her hospital course she was found to have extensive clinical left sided subcutaneous emphysema. This prompted a chest X-ray revealing a new left small to moderate basilar pneumothorax with diffuse subcutaneous emphysema (Fig. 4A). Expectant management was pursued, and sequential X-rays showed pneumothorax stability and two days later follow up chest x-ray identified an additional small right sided apical pneumothorax (Fig. 4B). Over the course of the next several days her vent settings decreased, but she was unable to be completely weaned from the ventilator. Eleven days after the initial pneumothorax, the patient remained stable and chest x-ray showed resolution of her pneumothoraces with unchanged subcutaneous emphysema. The patient is currently on minimal ventilator settings and is awaiting tracheostomy placement.
Although there are multiple presentations, respiratory disease is the primary manifestation of a severe COVID-19 infection. For managing severe ARDS due to COVID-19, current guidelines from the United States National Institutes of Health recommend using “low tidal volume ventilation (VT 4–8 mL/kg of predicted body weight) over higher tidal volumes (VT > 8 mL/kg)” and “prone ventilation for 12 to 16 hours per day over no prone ventilation” for hypoxia refractory to optimized ventilatory settings.6 Chest CT is an instrumental part of the workup and assessment of disease severity with the most common findings being bilateral ground glass opacities. COVID-19 infection has already shown lung parenchymal changes that progressed to large bulla, which coalesce and enlarge over time leading to bullous emphysematous disease and subpleural blebs.2 This could predispose this population to developing pneumothorax or pneumomediastinum, which have already been reported in the literature.7 One explanation for the pneumomediastinum could be the Macklin effect, where air from ruptured alveoli dissects along bronchovascular planes and into the mediastinum.8,9 This is in contrast to a pneumothorax where the alveolar rupture is involved with injury to the visceral pleura resulting in air accumulation in the pleural space. A small asymptomatic primary pneumothorax can typically be managed with observation and sequential imaging to ensure stabilization or re-expansion of the lung. However, barotrauma from positive pressure ventilation is a well-known cause of iatrogenic pneumothorax and the current recommendation for critically ill patients who are intubated in the ICU is tube thoracostomy placement.3 To the best of our knowledge, there are currently no recommendations specifically for managing a small pneumothorax in a COVID-19 positive patient. In each of these cases of pneumothorax due to barotrauma we decided to pursue non-operative management. Factors contributing to this decision were the small size of the pneumothoraces and the fact that the patient would need to be disconnected from the ventilator to allow the lung to drop to avoid parenchymal injury, which could be detrimental to an already critical patient. An additional benefit was limiting viral exposure to hospital staff. The limitations of this study is that there were only 4 cases encountered making it difficult to apply to a larger group, and that the pneumothoraces were very tiny, leaving no guidance for those with small or moderate sized pneumothoraces. While expectant management can be quite precarious in this population, we believe these cases show that observation in ventilated COVID-19 positive patients with pneumothorax may be an appropriate option. We hypothesize that alterations in lung mechanics in response to the SARS-CoV-2 infection allowed for small pneumothoraces to remain stable while receiving positive pressure ventilation. As the COVID-19 pandemic continues to unfold we will learn more about the exact pathophysiology that occurs.
Coronavirus disease 2019
positive end expiratory pressure