Content area
Full Text
Introduction
Carbon monoxide (CO), a colorless and odorless toxic gas that competes with oxygen for hemoglobin binding, is the most common cause of poisoning-related deaths and complications worldwide [1,2] . Unintentional CO poisoning is responsible for approximately 15,000 emergency department (ED) visits and nearly 500 deaths annually in the United States [2] . In the last decade, the number of intentional CO poisoning increased, particularly in some Asian countries [3] . Hyperbaric oxygen therapy (HBOT) enhances CO elimination, which is regarded as the therapy for severely poisoned patients [4] . Prognostic factors associated with outcome, such as age, history of exposure, consciousness, myocardial injury, lactic acidosis, carboxyhemoglobin (COHb), serum biochemistry markers, and pallidoreticular lesion (necrosis) on brain image have been proposed [4-8] .
Carbon monoxide causes a combination of tissue hypoxia by reducing oxygen delivery to tissues and direct CO-mediated damage at the cellular level. The most vulnerable organs to CO-induced hypoxia are the heart and the brain because of their high metabolic rate [9] . A large proportion of patients with severe CO poisoning have loss of consciousness and ischemic cardiac changes, which may result in acute respiratory failure through the pathophysiology of airway obstruction, atelectasis, and pulmonary edema [10] . Mechanical ventilation (MV) in a monoplace chamber is required for these patients that need HBOT [11] . The need for endotracheal (ET) intubation is strongly associated with mortality in a study enrolled 1,505 consecutive patients with CO poisoning treated with hyperbaric oxygen [5] .
Previous studies evaluated outcome of CO poisoning primarily with regard to mortality and morbidity, particularly neurologic sequelae. For patients receiving critical care, prolonged MV predisposes patients to ventilator-induced lung injury, ventilator-associated pneumonia, and several extra-pulmonary complications such as acute renal insufficiency, GI hemorrhage, and deep vein thrombosis [12] . The duration of MV also affects healthcare costs [13] . Researching factors associated with early extubation is of interest. However, there is no information in the literature regarding the factors that impact the duration of MV after severe CO poisoning.
The objective of this retrospective study was to identify the predictors for duration of MV in patients with severe CO poisoning and acute respiratory failure. Clinicians in the ED and intensive care unit (ICU) accordingly could use these predictors to...