Please see Bibliography of References for a list of abstracts, manuscripts and posters.

Other Studies

Near-infrared spectroscopy monitoring tissue oxygen saturation after cardiac surgery

Kopp R, Rex S, Dommann K, Schalte G, Dohmen G, Marx G, Rossaint R. Crit Care. 2009;13(Suppl 1):P239.

Introduction: Aim of this study was to compare near-infrared spectroscopy with global parameters of tissue oxygenation after cardiac surgery, such as cardiac output (CI), mixed venous oxygen saturation (SvO₂) or lactate concentration. After cardiac surgery circulating blood volume and cardiac function is regularly reduced on the Intensive Care Unit (ICU). This results in reduced microperfusion and peripheral vasoconstriction. The non-invasive InSpectra StO₂-monitor (Hutchinson Technology Inc.) measures the oxygen saturation in the microcirculation of the thenar muscle.

Methods: 40 patients after cardiac surgery were monitored with a StO₂-monitor and a Swan-Ganz catheter measuring CI and SvO2 on the ICU. Additionally intermittent lactate and blood gas analysis was performed. ANOVA was used for statistics of results.

Results: Mean Euro-Score of the patients was 6.5±3.7 including 24 aortocoronary bypass, 5 heart valve, 3 ascending aorta and 8 combined cardiac operations. After admission StO₂, CI and SvO₂ were significantly reduced. Lactate concentration and noradrenaline dose were increased (p<0.05). On day 1 noradrenaline dose dropped after fluid substitution, but only StO₂ value recovered.

Conclusions: After heart surgery StO₂ indicated the reduction as well as the recovery of microcirculation early, whereas lactate concentration and SvO₂ seemed to demonstrate a delayed response especially of recovery. Management of postoperative fluid and catecholamine therapy by StO₂ to optimize microcirculation should be subject of further studies.

References:

Myers DE et al. J Biomed Opt 2005;10:03401

Tschaikowsky K et al. Crit Care Med 2000;28: 336-34