Impact of emergency intubation on central venous oxygen saturation in critically ill patients: a multicenter...

Central venous oxygen saturation (ScvO2) has emerged as an important resuscitation goal for critically ill patients. Nevertheless, growing concerns about its limitations as a perfusion parameter have been expressed recently, including the uncommon finding of low ScvO2 values in patients in the intensive care unit (ICU). Emergency intubation may induce strong and eventually divergent effects on the physiologic determinants of oxygen transport (DO2) and oxygen consumption (VO2) and, thus, on ScvO2. Therefore, we conducted a study to determine the impact of emergency intubation on ScvO2.

In this prospective multicenter observational study, we included 103 septic and non-septic patients with a central venous catheter in place and in whom emergency intubation was required. A common intubation protocol was used and we evaluated several parameters including ScvO2 before and 15 minutes after emergency intubation. Statistical analysis included chi-square test and t test.

ScvO2 increased from 61.8 +/- 12.6% to 68.9 +/- 12.2%, with no difference between septic and non-septic patients. ScvO2 increased in 84 patients (81.6%) without correlation to changes in arterial oxygen saturation (SaO2). Seventy eight (75.7%) patients were intubated with ScvO2 less than 70% and 21 (26.9%) normalized the parameter after the intervention. Only patients with pre-intubation ScvO2 more than 70% failed to increase the parameter after intubation.

ScvO2 increases significantly in response to emergency intubation in the majority of septic and non-septic patients. When interpreting ScvO2 during early resuscitation, it is crucial to consider whether the patient has been recently intubated or is spontaneously breathing.