Pulmonary artery perfusion versus no pulmonary perfusion during cardiopulmonary bypass in patients with COPD: a randomised clinical trial

Abstract

IntroductionAbsence of pulmonary perfusion during cardiopulmonary bypass (CPB) may be associated with reduced postoperative oxygenation. Effects of active pulmonary artery perfusion were explored in patients with chronic obstructive pulmonary disease (COPD) undergoing cardiac surgery.Methods90 patients were randomised to receive pulmonary artery perfusion during CPB with either oxygenated blood (n=30) or histidine-tryptophan-ketoglutarate (HTK) solution (n=29) compared with no pulmonary perfusion (n=31). The coprimary outcomes were the inverse oxygenation index compared at 21 hours after starting CPB and longitudinally in a mixed-effects model (MEM). Secondary outcomes were tracheal intubation time, serious adverse events, mortality, days alive outside the intensive care unit (ICU) and outside the hospital.Results21 hours after starting CPB patients receiving pulmonary artery perfusion with normothermic oxygenated blood had a higher oxygenation index compared with no pulmonary perfusion (mean difference (MD) 0.94; 95% CI 0.05 to 1.83; p=0.04). The blood group had also a higher oxygenation index both longitudinally (MEM, p=0.009) and at 21 hours (MD 0.99; CI 0.29 to 1.69; p=0.007) compared with the HTK group. The latest result corresponds to a difference in the arterial partial pressure of oxygen of 23 mm Hg with a median fraction of inspired oxygen of 0.32. Yet the blood or HTK groups did not demonstrate a longitudinally higher oxygenation index compared with no pulmonary perfusion (MEM, p=0.57 and 0.17). Similarly, at 21 hours there was no difference in the oxygenation index between the HTK group and those no pulmonary perfusion (MD 0.06; 95% CI −0.73 to 0.86; p=0.87). There were no statistical significant differences between the groups for the secondary outcomes.DiscussionPulmonary artery perfusion with normothermic oxygenated blood during cardiopulmonary bypass appears to improve postoperative oxygenation in patients with COPD undergoing cardiac surgery. Pulmonary artery perfusion with hypothermic HTK solution does not seem to improve postoperative oxygenation.Trial registration numberNCT01614951; Pre-results.

Lung Protection Strategies during Cardiopulmonary Bypass Affect the Composition of Blood Electrolytes and Metabolites—A Randomized Controlled Trial

“…Besides HTK, pulmonary artery perfusion with normothermic oxygenated blood during CPB has also been found to reduce lung ischemia-reperfusion injury with improved postoperative oxygenation and lung compliance, and reduced intubation time [ 22 , 26 , 27 , 45 ]. In the original paper, from the randomized Pulmonary Protection Trial of adult patients undergoing elective cardiac surgery [ 46 ], we found that postoperative arterial oxygenation was higher 20 h post-CPB in patients receiving pulmonary perfusion with oxygenated blood during CPB, compared to those receiving HTK solution or standard CPB without pulmonary perfusion. However, baseline mean arterial oxygenation was 20% higher in the patients receiving pulmonary perfusion with oxygenated blood compared to the two other groups baseline values [ 46 ].…”

“…Currently, no randomized studies have compared the effects of pulmonary artery perfusion with HTK solution or oxygenated blood, versus standard CPB, and little is known about the molecular mechanisms of these regimens. Hence, the main aim of this sub-study is to compare the molecular effects of hypothermic HTK solution and normothermic oxygenated blood to the standard CPB regimen without pulmonary perfusion, on blood obtained from COPD patients included in the randomized Pulmonary Protection Trial [ 46 ]. In particularly, we aim to find changes in arterial blood gases, electrolytes, plasma inflammatory protein interleukin-6 (IL-6), and plasma metabolites associated with ischemia-reperfusion injury and the received regime.…”

Chronic Obstructive Pulmonary Disease and Off-Pump Coronary Surgery

“…These complications are much more common in the patients with COPD and rate of mortality might increase up to 3.8%. 13 , 14 ) The main reasons causing these complications might include application of general anesthesia, use of cardiopulmonary bypass, and placement of cross-clamp, which are known to generate postoperative hypoxia through reducing functional residual capacity, forming compression atelectasis, and making pulmonary shunts. Moreover, previous studies indicate that various surgical manipulations such as sternotomy, removal of left internal mammary artery, and opening of the pleura are shown to yield temporary reduction in vital capacity.…”

Mechanical ventilation and cardiopulmonary bypass: a narrative review of the mechanistic lung protective measures

“…In humans, the impact of continuous pulmonary perfusion during extracorporeal circulation on reducing postoperative lung injury remains controversial [96][97][98] . Santini et al [96] compared pulsatile pulmonary perfusion during CPB with conventional CPB in patients undergoing cardiac surgery.…”

“…The pulsatile pulmonary perfusion group showed increased PaO 2 /FiO 2 and lung compliance with reduced neutrophils in the bronchoalveolar lavage when compared to the conventional group. Moreover, pulmonary perfusion has been also associated with an increased postoperative oxygenation when compared to the use of histidine-tryptophan-ketoglutarate solution during CPB in patients undergoing cardiac surgery [97] . Even though pulmonary perfusion during CPB reduces the postoperative inflammatory response and improves oxygenation, long-term benefits are yet to be determined.…”