Please see Bibliography of References for a list of abstracts, manuscripts and posters.
Ali SZ, Taniguchi Y, Zmoos S, Kurz A. Eur J Anaesthesiol. 2006;23(Supp S37):216. Abstract A-837.
Background and Goal: Near infra-red spectroscopy (NIRS) has been shown to be a non-invasive method for determining tissue oxygen saturation (St02) [1, 2]. In an observational study, we investigated the influence of mild hypothermia and rewarming on NlRS-derived St02.
Materials and Methods: We studied six healthy volunteers (age23 ± 4 yrs, weight 71 ± 10kg) during general iv anesthesia with propofol and mivacurium; and an Fi02 of 0.35. Maintenance iv fluids were given. They were cooled from approx. 36°C to target core temperature of 34°C. They were approx. 34°C for 1hr before being rewarmed to normal all with circulating water garment.
Results: Data analysis was at five temperature periods ie, 36.5 ± 0.5; 35.5 ± 0.5; 34.5 ± 0.5; 35.5 ± 0.5; 36.5 ± 0.5°C. The means (± SD) of St02 (%) at these periods were 73 ± 8, 71 ± 11, 67 ± 14, 68 ± 11, 74 ± 7. Figure below shows the St02 in box plot, with boxes as interquartile range, horizontal dark lines as medians, vertical lines as minimum and maximum. Friedman rank sum test showed statistically significant changes in St02 (p < 0.05) at the end of both cooling (to 34.5 ± 0.5) and rewarming phase (to 36.5 ± 0.5).
Conclusions: NIRS can be used to serially assess the changes in St02 during mild hypothermia and rewarming. Higher inter-individual variability occurred during mild hypothermia.
References:
1 Comerota AJ, et al. J VaseSurg 2003; 38:724-9.
2 Mancini DM, et al. J Appl Physiol1994; 77:2740-7.