Research

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

Glenn Hernandez¹ , Hector Peña² , Rodrigo Cornejo³ , Maximiliano Rovegno¹ , Jaime Retamal¹ , Jose Luis Navarro³ , Ignacio Aranguiz¹ , Ricardo Castro¹ and Alejandro Bruhn¹

¹Pontificia Universidad Católica de Chile, Departamento de Medicina Intensiva, Marcoleta 367, Santiago, Chile

²Instituto Nacional de Cardiología Ignacio Chávez, UTI de Cardio-Neumología, Juan Badiano No. 1 C.P. 14080, Ciudad de México, México

³Hospital Clínico Universidad de Chile, Unidad de Pacientes Críticos, Santos Dumont 999, Santiago, Chile

author email corresponding author email

Critical Care 2009, 13:R63doi:10.1186/cc7802

Published:	4 May 2009

See related commentary by Stahl et al., http://ccforum.com/content/13/4/172

Abstract

Introduction

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.

Methods

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.

Results

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.

Conclusions

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.