Limitation of tube thoracostomy in treating pneumothorax in COVID-19 infected patients. A retrospective cohort study.

Background: COVID infection is caused by the highly contagious SARS-CoV-2(Severe acute respiratory syndrome coronavirus 2). The first outbreak of this infection was in Wuhan, China in December 2019. Since then, it has spread rapidly across the world, with more than 100000 new cases each day. Among those infected with SARS-COV-2 up to 20% develop severe disease requiring hospitalization. Among those who are hospitalized, one quarter will need ICU admission. Admission to the ICU is due to respiratory failure or pneumonia. The pneumonia associated with COVID infection may lead to respiratory failure requiring endotracheal intubation and mechanical ventilation. An important complication of mechanical ventilation is barotrauma. Barotrauma appears to be common in COVID patients. Pneumothorax developed in 25% of COVID patients who had barotrauma. In COVID the percentage of patients with mild symptoms who develop a pleural effusion is 8% compared to 28% in patients who are critically ill. Most of the COVID infected that have a pneumothorax or pleural effusion need a thoracostomy. In trauma cases most, thoracic injuries (leading to pneumothorax or hemothorax) are effectively treated with tube thoracostomy.

Objectives: First objective is to compare the therapeutic effect of tube thoracostomy on COVID infected patients who have pneumothorax or pleural effusion to those non-COVID infected patients who had traumatic pneumothorax or pleural effusion treated by tube thoracostomy. Second objective is to study the morbidity associated with tube thoracostomy in COVID infected patients who have pneumothorax or pleural effusion.

Patients And Methods: This study was conducted in Sheikh Khalifa medical city Ajman, United Arab Emirates. It is a descriptive, observational, retrospective cohort study. One hundred patients were recruited from the January 1, 2020 to the December 31, 2020. Patients were divided into two groups. First group includes fifty adult COVID infected patients who had no trauma. Second group includes fifty adult COVID infection free patients who had trauma. : COVID infected patients with an age equal to or above 18 years, of both genders, with history of pneumothorax, pleural effusion or both of them, needed insertion of thoracostomy chest tube. Patients with an age equal to or above 18 years, of both genders, with history of traumatic pneumothorax, pleural effusion (hemothorax) or both of them, needed insertion of thoracostomy chest tube. : Children, Adult COVID infected patients who didn't have pneumothorax or plural effusion, adult COVID infected patients who had pneumothorax or plural effusion without a need for tube thoracostomy. : Adult non-COVID infected patients who had trauma, but didn't have pneumothorax or pleural effusion, adult non-COVID infected patients who had traumatic pneumothorax or pleural effusion without a need for tube thoracostomy. The collected data was revised, coded, tabulated and introduced to a PC using Statistical package for Social Science (SPSS 25). Mann Whitney Test ( test) was used to assess the statistical significance of the difference of a non-parametric variable between two study groups. Chi-Square test was used to examine the relationship between two qualitative variables. Fisher's exact test was used to examine the relationship between two qualitative variables when the expected count is less than 5 in more than 20% of cells.

Results: Most of patients in trauma group (group 2) were with the age range of 20-40-year (58.8% of patients) P value was significant (<0.001). In COVID infected patients' group (group 1) the age range was 40-60 year (50%of patients). P Value (<0.001) was significant too. Male was the dominant gender in group 2 (96.1% of patients were male), while in group1 (78% of patients were male), P Value was significant (0.007). No co-morbidities (diabetes, hypertension, ischemic heart disease, Asthma and dyslipidemia) were detected in group 2 (0.0%). Co-morbidity were detected in 76% of patients in group 1, P Value was significant (<0.001). Hemothorax occurred in 37.3% of patients in group 2, and no cases of hemothorax was detected in group 1. P Value was significant (<0.001). Complications of chest tube insertion took place in group 2 as follows; tube malposition in 13.7% of patients, tube blockade in 3.9% of patients. The percentage in group 1 was as follows tube malposition in 16% of patients, tube blockade in 18%. The difference between the two was not significant for tube malposition (P value 0.748) and significant for tube blockade (P value 0.023). Subcutaneous emphysema occurred in 15.7% of patients in group 2 and in 15.7% of patients in group 1. The difference was not significant (P value was 0.118). Acquired bronchopleural fistula occurred 2.0% of group 1 cases. No cases of this fistula were documented in group 2. Number of chest tubes needed to be inserted in group 2 patients was as follows (one chest tube in: 74.5% of patients, two chest tubes in: 23.5% of patients. Three chest tubes or more in 2% of patients). While in group1 patients' number of chest tubes needed to be inserted was (one in 56% of patients, two in 30% of patients. Three or more in 14% of patients). The difference was significant only in those who required insertion of three chest tubes or more (P value was 0.028). The median duration needed to keep a chest tube was 3 days in group 2, and 7 days in group 1. The difference between the two was significant (P value was 0.000). Death was the fate of 3.9% of patients in group 2 and in 64% of patients in group 1. The difference was significant (P value was< 0.001).

Conclusion: Therapeutic effect of tube thoracostomy in treating Adult COVID patients who had pneumothorax or pleural effusion is less than that used in treating trauma non-COVID patients who had pneumothorax or plural effusion. Morbidity and mortality related to tube thoracostomy applied to treat pneumothorax or pleural effusion in adult COVID patients is more than that in trauma non COVID patients.