SummaryArterial hypotension with vasopressor dependence is a major problem after cardiac surgery. We evaluated the early postoperative course of 1558 consecutive patients scheduled for cardiac surgery, and compared the outcome of patients with and without vasopressor dependence (defined as the need for > 0.1 lg.kg )1 .h )1 noradrenaline for > 3 h in the face of normovolaemia).Vasopressor dependence was diagnosed in 424 patients (27%) and was associated with a higher incidence of postoperative renal failure (67 (15.7%) vs 7 (0.6%), respectively; p < 0. .

General anaesthesia with isoflurane significantly reduces plasma AEA concentrations. This could be a consequence of stress reduction after loss of consciousness. The significant increase in 2-AG after initiation of CPB may be part of an inflammatory response. These findings suggest that anaesthesia and surgery have differential effects on the ECS which could have substantial clinical consequences.

No abstract

SummaryPeri-operative acute renal failure requiring renal replacement therapy is common (5-30%) after cardiac surgery and associated with a mortality of 50%. Pre-operative renal impairment seems to be the most important risk factor for frank postoperative renal failure. To help evaluate the risk factors, we conducted a prospective observational trial of 1574 consecutive patients with normal pre-operative renal function (creatinine < 110 lmol.l )1). Renal failure was defined as the need for renal replacement therapy. After univariate analysis of previously described risk factors, those who differed significantly between patients with or without renal failure were enrolled into a multivariate classification and regression tree (CART) statistical model that identifies the most 'predictive' risk factors and creates a ranked list of these. In patients with pre-operatively normal renal function, a serum level of lactate > 1.1 mmol.l )1 in the first 24 h after the operation was the strongest predictor for the development of renal failure. Acute renal failure (ARF) is a major morbid event in patients after cardiac surgery with an incidence of 5-30% and mortality of 28-50% [1]. ARF requiring renal replacement therapy (RRT) occurs in 1-5% of cases and is associated with an even higher mortality. Cardiopulmonary bypass (CPB) seems to be an important intra-operative trigger for ARF [2] since it is in turn associated with hypotension, low haematocrit, hypothermia, renal vasoconstriction, and periods of non-pulsatile flow. Another important risk factor appears to be pre-existing chronic or acute renal insufficiency [3,4], but data relating to the perioperative course of patients with pre-operatively normal renal function is sparse. The aim of our study was to perform a risk and outcome analysis of ARF requiring renal replacement therapy in patients after cardiac surgery without significant pre-operative renal dysfunction. MethodsAfter ethical committee approval and informed consent, 1574 consecutive patients > 18 years old scheduled for coronary artery bypass grafting, valve surgery and combined procedures using cardiopulmonary bypass were enrolled in this prospective observational study from January 2003 to December 2005. Patients were excluded from the study if they were scheduled for cardiac transplantation or minimally invasive procedures, if they had pre-operative chronic renal dysfunction (serum creatinine > 110 lmol.l )1), and if the RRT was started later than the third postoperative day. The reason for this last criterion was that after the third postoperative day, factors other than operative procedure or anaesthetic technique supervene (e.g. sepsis). The requirement for RRT was suggested by: 1 oliguria (urine output < 0.5 ml.kg for > 3 h); 2 uraemia (> 25 mmol.l )1 );3 signs of fluid overload despite diuretic treatment for > 3 h; 4 hyperkalaemia (< 6 mmol.l )1 ).

No abstract