Poster presentation | Open | Published:
Tissue oxygen saturation does not correlate with the oxygen delivery index during major abdominal surgery
Critical Carevolume 12, Article number: P68 (2008)
Tissue oxygenation (STO2) measured by near-infrared spectroscopy (NIRS) has been shown to correlate with the global oxygen delivery index (DO2I) in both humans and animals during haemorrhagic shock and its fluid resuscitation . This is a pilot study to determine whether STO2 can be used as a surrogate marker of DO2I with a view to utilising this simple noninvasive technique to guide intraoperative haemodynamic therapy.
Eighteen patients undergoing major abdominal surgery were recruited from a London teaching hospital. All patients received the same induction and maintenance anaesthesia. Ten patients were actively haemodynamically optimised to a DO2I >600 ml/min/kg with fluid resuscitation. The DO2I was determined using an oesophageal Doppler probe cardiac output monitor (CardioQ; Deltex Medical, UK). The STO2 of the thenar muscle was determined using the InSpectra STO2 (Hutchinson Technology, USA). Paired measurements of the DO2I and STO2 were taken every 20 minutes from the start of surgery.
The average patient age was 67 (30–84) years; seven (39%) were female. A total of 173 paired observations were made. The median (IQR) for the DO2I and STO2 were 454 (332.5–595.5) and 88 (83–93), respectively. There was no correlation between the DO2I and STO2 (Figure 1; r = 0.1, P > 0.1). In addition there is no statistically significant difference in STO2 when the DO2I > 600 ml/min/m2 (paired t test, P = 0.6). STO2 did not track the changes in DO2I.
There is no clear relationship between STO2 and the DO2I during major abdominal surgery. STO2 in the intraoperative period cannot currently be used as a surrogate marker for oxygen delivery in this group of patients.
McKinley , et al.: J Trauma. 2000, 48: 637-642.