Moderate versus deep hypothermia for the arterial switch operation — experience with 100 consecutive patients

Abstract

The ASO under full-flow moderate compared to deep hypothermia was advantageous regarding length of procedure and primary chest closure rate. Moderate hypothermia seemed to be beneficial for pulmonary recovery, length of chest tube drainage treatment and inotropic support. No worse early or long-term effects of moderate hypothermia were found.

Randomized comparison between mild and moderate hypothermic cardiopulmonary bypass for neonatal arterial switch operation

“…In a previous report, comparison of moderate versus deep hypothermic CPB revealed 30% decrease in CPB time using the moderate hypothermia strategy in neonatal ASO [11]. This result was mainly associated with shorter rewarming and reperfusion times, leading to better oxygenation and lung compliance at the end of the operation.…”

“…Previous studies comparing moderate hypothermia to deep hypothermia or moderate hypothermia to normothermia revealed superior results for higher temperatures compared with lower [4,11]. However, there must be an optimal temperature that will ensure the superior beneficial advantages of normothermia and also provide protection for vital organs in the case of technical failure during perfusion of the body.…”

“…However, there must be an optimal temperature that will ensure the superior beneficial advantages of normothermia and also provide protection for vital organs in the case of technical failure during perfusion of the body. As published before, this temperature should be either normothermia or a temperature between normothermia and deep hypothermia [4,11]. In the light of previous knowledge mentioned above, we decided to prepare a new study comparing CPB temperatures lower than normothermia but higher than deep hypothermia for neonatal ASO.…”

“…However, the optimal temperature to use during the arterial switch procedure is a matter of debate [11]. Although nowadays adult cardiac surgery is often performed at normothermia [12], neonatal cardiac surgery using CPB is still performed at low temperatures in many centres [13].…”

“Flow and Rate”: Concept and Clinical Applications of a New Hemodynamic Theory

“…(Nardell, 2009), but with some side effects as well (Ishida, zt al., 2004); b) normothermia: that becomes more practiced in CPB with some proven advantages over hypothermia (Pouard, et al, 2006), which may be explained because blood is nearly Newtonian at 37.2°C (Box, et al 2005). Meanwhile, the benefits of normothermia on myocardial protection and microcirculation improvements remain controversial (Rastan, et al, 2008), as the myocardium is already protected with doses of cardioplegia, while the perfusion of microcirculation is more or less helped by the FahraeusLindqvist effect due to hemodilution; c) total or partial absenteeism of CPB: that becomes popular with proven postoperative hemodynamic advantages, but it is still a challenging technique reserved for selected groups of patients (Shroyer, et al, 2009); d) pulsatile perfusion flow devices: in a matter to keep ESS some pulsatile CPB have proven advantages clinically and experimentally (Ündar, et al,1999); (Undar, et al 2006). Despite that, recent studies recommend the unphysiological steady flow (Voss, et al, 2010).…”