Post-covid-19 necrotizing pneumonia in patients on invasive mechanical ventilation

(1) Background: Few reports of necrotizing pneumonia in patients with COVID-19 have been published. We have observed an elevated incidence at two hospitals in our city, suggesting this complication is not uncommon, and may have been overlooked. (2) Methods: This article presents a retrospective, descriptive cohort study that was undertaken from 22 March 2020 to 15 June 2021 in two tertiary care hospitals in Medellín, Colombia. All adult patients admitted to the intensive care unit (ICU) for respiratory failure related to confirmed COVID-19, on invasive mechanical ventilation (IMV), with imaging or surgical findings documenting necrotizing pneumonia (NP) were included. (3) Results: Of 936 patients with COVID-19 that required IMV, 42 (4.5%) developed NP. Overall mortality was 57% and in-hospital mortality was 71%, occurring 15-79 days after COVID-19 diagnosis. NP was diagnosed at a median of 27 days after COVID-19 symptom onset and 15.5 days after initiation of IMV. Infections were polymicrobial in 52.4% of patients. Klebsiella pneumoniae (57%) and Pseudomonas aeruginosa (33%) were the most common etiologic agents. Pulmonary embolism (PE) was documented in 13 patients overall (31%), and in 50% of patients who underwent an angioCT. Drainage and/or surgical procedures were performed on 19 patients (45.2%) with a 75% mortality rate. (4) Conclusions: In our experience, NP is a relatively common, albeit neglected, complication in mechanically ventilated COVID-19 patients, possibly originating in poorly vascularized areas of lung parenchyma. Associated mortality is high. Although drainage procedures did not seem to favorably impact patient outcomes, diagnosis and treatment were late events in the overall disease course, suggesting that early recognition and timely treatment could have a positive impact on prognosis.