Mark Wefers Bettink

Chapter 8 152 Table 1. Baseline patient characteristics and clinical data Variables Total (n=20) Age (yr) a 56.2 (± 11.7) Sex Male/female 10/10 BMI a 26.8 (± 3.7) Medical history Chronic obstructive pulmonary disease 10% (2) Hypertension 15% (3) Diabetes Mellitus 5% (1) Vascular event 22% (4) Surgery type Resection of a vestibular schwannoma 2/20 Hypophysectomy 6/20 Trepanation 12/20 Dexamethason use before surgery 40% (8) ASA I/II/III/IV 4/8/7/1 Blood pressure a (mmHg) Systolic 134.4 (±15.2) Diastolic 80.7 (±10.5) Heartrate (beats/min) a 74.8 (± 15.4) SpO 2 (%) a 97.4 (± 1.43) Blood loss (ml) a 217 (± 202) a = mean (standard deviation) Abbreviations: ASA, American Society of Anesthesiologists; BMI, body mass index; SpO 2 , oxygen saturation All 20 patients were hemodynamically stable during surgery, as described in the inclusion criteria. In all patients low doses vasopressors were needed to maintain MAP above 65 mmHg. In 14 patients noradrenaline was administered (0.05 mcg/kg/min ± 0.02 mcg/kg/ min) and phenylephrine was used in 6 patients (0.28 mcg/kg/min ± 0.14 mcg/kg/min). No rises in serum lactate level were observed. MAP, microcirculatory blood flow and tissue oxygen saturation were stable during surgery as presented in figure 1 (A, C and E). The mean skin temperature changed from baseline (start surgery) over time (figure 1B). In the first hour of operation, the mean skin temperature increased with more than 1 o C caused by a number of patients whose skin temperature rose more than two degrees. Baseline mitoPO 2 (± SD) was 60 ± 17 mmHg, and during surgery the mean mitoPO 2 remained between 60 and 40 mmHg but a slow decline from baseline was observed during the first hour of surgery (figure 1D).