The relation between arterial hyperoxia and mortality among intensive care unit patients with septic shock

Abstract

Context Oxygen should be regarded as any other drug with potential dose and time-dependent adverse effects. Health care practitioners are more likely to accept supranormal arterial oxygen levels as a wider safety buffer. Furthermore, the latest guidelines in the management of septic shock did not define upper limits for oxygenation in mechanically ventilated patients with septic shock.Aim To investigate whether hyperoxia is associated with higher mortality in patients with septic shock.Patients and methods This study was carried out on 200 patients with septic shock. After fulfilling the inclusion criteria, we recorded the clinical data, severity scoring systems, source of sepsis, ventilatory data, oxygenation status data, and the outcome parameters. We categorized the patients into two groups: group I (nonhyperoxic group), whose arterial oxygen tension was less than 120 mmHg in all arterial blood gas analyses during the ICU stay, and group II (hyperoxic group), whose arterial oxygen tension was more than or equal to 120 mmHg in at least one arterial blood gas analysis during ICU stay.Results Group I included 40 patients, whereas group II included 160 patients. Mortality rate was 57.5 and 89.4% in groups I and II, respectively. In group II, there were 16 patients who were exposed to 1 day of hyperoxia with a mortality rate of 75%, whereas there were 144 patients who were exposed to hyperoxia more than 1 day with a mortality rate of 91%.Conclusion Hyperoxia was associated with increased mortality, number of mechanical ventilation days, length of ICU stay, and hospital stay.