The impact of deep and moderate body temperatures on end-organ function during hypothermic circulatory arrest

Abstract

Higher levels of circulating lactate levels during reperfusion indicate less effective organ protection at 30 than at 20 °C after 60 min of HCA. This is further substantiated by histological evidence for a more pronounced oedema inflammatory response within the bowel wall.

Profound hypothermia compared with moderate hypothermia in repair of acute type A aortic dissection

“…8 Although PH increases the duration of CPB, postoperative bleeding, blood transfusion, generalized endothelial dysfunction, neuronal apoptosis, and postoperative pulmonary complications, [14][15][16][17][18] MH may not provide adequate protection for the spinal cord and visceral organs, especially under prolonged duration of CA. Khaladj and colleagues 26 compared moderate (30 C) and deep hypothermia (20 C) in an animal model and reported higher levels of circulating lactate during reperfusion, indicating less effective organ protection at 30 C than at 20 C. However, in their study, the CA time was 60 minutes, which is high compared with our study and most reported series. With prolonged circulatory arrest times of 45 minutes or longer, mild or moderate hypothermia may not be safe without adjunctive SACP as the linear relationship between neurologic deficit and duration of CA increases steeply after 50 minutes of CA.…”

Moderate hypothermic circulatory arrest in total arch repair for acute type A aortic dissection: clinical safety and efficacy

“…As shown in Table 1, the two groups were similar in age, body mass index and other preoperative variables (P>0.05), except the MHCA group had a higher percentage of hypertension (89.7% vs. 71.4%, P=0.045) and cardiac tamponade (30.8% vs. 11.4%, P=0.044). Preoperative visceral functions as indicated by the concentrations of creatinine (kidney), aspartate aminotransferase and total bilirubin (liver) and lactate (bowels) (14) did not differ significantly between the two groups (P>0.05; Table 1).…”

Neuroprotective Strategies in Repair and Replacement of the Aortic Arch

“…With regard to the viscera, Khaladj et al found, in a porcine model, that hypothermia at 30°C resulted in higher serum lactate levels and more histologic findings of bowel wall inflammation compared with arrest at 20°C. 106 In another porcine experiment, Haldenwang et al demonstrated elevated inflammatory markers in ACP compared with animals with ACP plus continued lower body perfusion. 107 These findings were alarming in their suggestion that milder hypothermia may create need for trade-off between visceral and cerebral maintenance.…”