Outcome Prediction in Patients with Severe COVID-19 Requiring Extracorporeal Membrane Oxygenation-A Retrospective International Multicenter Study.

The role of veno-venous extracorporeal membrane oxygenation therapy (V-V ECMO) in severe COVID-19 acute respiratory distress syndrome (ARDS) is still under debate and conclusive data from large cohorts are scarce. Furthermore, criteria for the selection of patients that benefit most from this highly invasive and resource-demanding therapy are yet to be defined. In this study, we assess survival in an international multicenter cohort of COVID-19 patients treated with V-V ECMO and evaluate the performance of several clinical scores to predict 30-day survival. METHODS: This is an investigator-initiated retrospective non-interventional international multicenter registry study (NCT04405973, first registered 28 May 2020). In 127 patients treated with V-V ECMO at 15 centers in Germany, Switzerland, Italy, Belgium, and the United States, we calculated the Sequential Organ Failure Assessment (SOFA) Score, Simplified Acute Physiology Score II (SAPS II), Acute Physiology And Chronic Health Evaluation II (APACHE II) Score, Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) Score, Predicting Death for Severe ARDS on V­V ECMO (PRESERVE) Score, and 30-day survival. RESULTS: In our study cohort which enrolled 127 patients, overall 30-day survival was 54%. Median SOFA, SAPS II, APACHE II, RESP, and PRESERVE were 9, 36, 17, 1, and 4, respectively. The prognostic accuracy for all these scores (area under the receiver operating characteristic-AUROC) ranged between 0.548 and 0.605. CONCLUSIONS: The use of scores for the prediction of mortality cannot be recommended for treatment decisions in severe COVID-19 ARDS undergoing V-V ECMO; nevertheless, scoring results below or above a specific cut-off value may be considered as an additional tool in the evaluation of prognosis. Survival rates in this cohort of COVID-19 patients treated with V­V ECMO were slightly lower than those reported in non-COVID-19 ARDS patients treated with V-V ECMO.

Inhalation Injury and Toxic Industrial Chemical Exposure.

Toxic industrial chemicals include chlorine, phosgene, hydrogen sulfide, and ammonia have variable effects on the respiratory tract, and maybe seen alone or in combination, secondary to inhalation injury. Other considerations include the effects of cyanide, carbon monoxide, and fire suppressants. This Clinical Practice Guideline (CPG) will provide the reader with a brief overview of these important topics and general management strategies for each as well as for inhalation injury. Chlorine, phosgene, hydrogen sulfide, and ammonia are either of intermediate or high water solubility leading to immediate reactions with mucous membranes of the face, throat, and lungs and rapid symptoms onset after exposure. The exception to rapid symptom onset is phosgene which may take up to a day to develop severe acute respiratory distress syndrome. Management of these patients includes early airway management, lung-protective ventilator strategies, aggressive pulmonary toilet, and avoidance of volume overload.

Acute Respiratory Failure.

Acute respiratory distress syndrome (ARDS) is a condition affecting critically ill patients, characterized by pulmonary inflammation and defects in oxygenation due to either direct or indirect injury to the lungs. These guidelines will define the diagnosis and management of ARDS, particularly among combat casualties and patients in the deployed environment. The cornerstone of management of ARDS involves maintaining adequate oxygenation while avoiding further pulmonary injury through lung-protective ventilation. Additional strategies for advanced respiratory failure, such as prone positioning, neuromuscular blockade, and extracorporeal membrane oxygenation will be reviewed here as well. Particularly important to the care of the patient with ARDS in the deployed environment is a familiarity with the challenges and indications for transport/aeromedical evacuation.