Excessive haemodilution and the resulting anaemia during CPB is accompanied by a decrease in the total arterial oxygen content, which may impair tissue oxygen delivery. Hyperoxic ventilation has been proven to improve tissue oxygenation in different pathophysiological states of anaemic tissue hypoxia. The aim of this study was to examine the influence of arterial hyperoxaemia on tissue oxygenation during CPB. Records of patients undergoing isolated CABG with CPB were retrospectively reviewed. Patients with nadir haematocrit levels below 20% during CPB were included in the study. Tissue hypoxia was defined as hyperlactataemia (lactate >2.2 mmol/L) coupled with low ScVO2 (ScVO2 <70%) during CPB. One hundred patients with normoxaemia and 100 patients with hyperoxaemia were included in the study. Patients with hyperoxaemia had lower tissue hypoxia incidence than patients with normoxaemia (p<0.001). Compared with patients without tissue hypoxia, patients with tissue hypoxia had significantly lower PaO2 values (p<0.001) and nadir haematocrit levels (p<0.001). Nadir haematocrit levels <18% (OR: 5.3; 95% CI: 2.67–10.6; p<0.001) and hyperoxaemia (OR: 0.28; 95% CI: 0.14–0.56; p<0.001) were independently associated with tissue hypoxia.
Conclusions:
Hyperoxaemia during CPB may be protective against tissue hypoxia in patients with nadir haematocrit levels <20%.
HabibRHZachariasASchwannTA. Adverse effects of low hematocrit during cardiopulmonary bypass in the adult: should current practice be changed?J Thorac Cardiovasc Surg2003; 125: 1438–1450.
2.
HorwichTBFonarowGCHamiltonMA. Anemia is associated with worse symptoms, greater impairment in functional capacity and a significant increase in mortality in patients with advanced heart failure. J Am Coll Cardiol2002; 39: 1780–1786.
3.
RanucciMBiagioliBScollettaS. Lowest hematocrit on cardiopulmonary bypass impairs the outcome in coronary surgery: An Italian Multicenter Study from the National Cardioanesthesia Database. Tex Heart Inst J2006; 33: 300–305.
4.
KarkoutiKDjaianiGBorgerMA. Low hematocrit during cardiopulmonary bypass is associated with increased risk of perioperative stroke in cardiac surgery. Ann Thorac Surg2005; 80: 1381–1387.
5.
SwaminathanMPhilips-ButeBGConlonPJ. The association of lowest hematocrit during cardiopulmonary bypass with acute renal injury after coronary artery bypass surgery. Ann Thorac Surg2003; 76: 784–792.
6.
DeFoeGRRossCSOlmsteadEM. Lowest hematocrit on bypass and adverse outcomes associated with coronary artery bypass grafting. Ann Thorac Surg2001; 71: 769–776.
7.
SpiessBD. Transfusion of blood products affects outcome in cardiac surgery. Semin Cardiothorac Vasc Anesth2004; 8: 267–281.
8.
VincentJLSakrYDe BackerD. Efficacy of allogeneic red blood cell transfusions. Best Pract Res Clin Anaesthesiol2007; 21: 209–219.
9.
van BommelJTrouwborstASchwarteL. Intestinal and cerebral oxygenation during severe isovolemic hemodilution and subsequent hyperoxic ventilation in a pig model. Anesthesiology2002; 97: 660–670.
10.
LeonovYSafarPSterzF. Extending the golden hour of hemorrhagic shock tolerance with oxygen plus hypothermia in awake rats: An exploratory study. Resuscitation2002; 52: 193–202.
11.
KemmingGMeisnerFKleenM. Hyperoxic ventilation at the critical hematocrit. Resuscitation2003; 56: 289–297.
12.
MeierJKemmingGKisch-WedelH. Hyperoxic ventilation reduces 6-hour mortality at the critical hemoglobin concentration. Anesthesiology2004; 100: 70–76.
13.
MeierJKemmingGKisch-WedelH. Hyperoxic ventilation reduces 6-hour mortality after partial fluid resuscitation from hemorrhagic shock. Shock2004; 22: 240–247.
14.
ParolariAAlamanniFGherliT. Cardiopulmonary bypass and oxygen consumption: oxygen delivery and hemodynamics. Ann Thorac Surg1999; 67: 1320–1327.
15.
JoachimssonPOSjöbergFForsmanM. Adverse effects of hyperoxemia during cardiopulmonary bypass. J Thorac Cardiovasc Surg1996; 112: 812–819.
16.
KuttilaK. Response of tissue oxygenation to systemic hyperoxia after cardiac surgery. Crit Care Med1990; 18: 369–372.
17.
De BlasiRATonelliEArcioniR. In vivo effects on human skeletal muscle oxygen delivery and metabolism of cardiopulmonary bypass and perioperative hemodilution. Intensive Care Med2012; 38: 413–421.
18.
HoJSibbaldWJChin-YeeIH. Effects of storage on efficacy of red cell transfusion: when is it not safe?Crit Care Med2003; 31: S687–S697.
19.
HablerOPKleenMSHutterJW. Effects of hyperoxic ventilation on hemodilution-induced changes in anesthetized dogs. Transfusion1998; 38: 135–144.
20.
WeiskopfRBFeinerJHopfHW. Oxygen reverses deficits of cognitive function and memory and increased heart rate induced by acute severe isovolemic anemia. Anesthesiology2002; 96: 871–877.
21.
MeierJKemmingGMeisnerF. Hyperoxic ventilation enables hemodilution beyond the critical myocardial hemoglobin concentration. Eur J Med Res2005; 10: 462–468.
22.
HablerOKleenMKemmingG. Hyperoxia in extreme hemodilution. Eur Surg Res2002; 34: 181–187.
HameedSMAirdWCCohnSM. Oxygen delivery. Crit Care Med2003; 31: S658–S667.
25.
WettsteinRTsaiAGErniD. Improving microcirculation is more effective than substitution of red blood cells to correct metabolic disorder in experimental hemorrhagic shock. Shock2004; 21: 235–240.
26.
FeinerJRFinlay-MorrealeHEToyP. High oxygen partial pressure decreases anemia-induced heart rate increase equivalent to transfusion. Anesthesiology2011; 115: 492–498.
27.
PapeAMeierJKertschoH. Hyperoxic ventilation increases the tolerance of acute normovolemic anemia in anesthetized pigs. Crit Care Med2006; 34: 1475–1482.
28.
PapeAStecheMLaoutM. The limit of anemia tolerance during hyperoxic ventilation with pure oxygen in anesthetized domestic pigs. Eur Surg Res2013; 51: 156–169.
29.
KaruITaalGZilmerKPruunsildCStarkopfJZilmerM. Inflammatory/oxidative stress during the first week after different types of cardiac surgery. Scand Cardiovasc J2010; 44: 119–124.
30.
ZakkarMGuidaGSuleimanMSAngeliniGD. Cardiopulmonary bypass and oxidative stress. Oxid Med Cell Longev2015; 2015: 189863.
31.
MittalMSiddiquiMRTranKReddySPMalikAB. Reactive oxygen species in inflammation and tissue injury. Antioxidants & Redox Signaling2014; 20: 1126–1167.
