combination of lowest hematocrit during cardiopulmonary bypass and acute renal injury after coronary artery bypass surgery

Acute renal insult is a common serious complication of cardiopulmonary bypass. Moderate hemodilution is thought to reduce the risk of kidney injury but the current practice of extreme hemodilution [hematocrit 22% to 24%] during cardiopulmonary bypass has been linked to adverse outcomes after cardiac surgery. Therefore we tested the hypothesis that lowest hematocrit during cardiopulmonary bypass is independently associated with acute renal injury after cardiac surgery. Demographic perioperative, and laboratory data were gathered for 140 primary elective coronary bypass surgery patients, preoperative and daily postoperative creatinine values were measured until hospital discharge. Stepwise multivariable linear regression analysis was performed to determine whether lowest hematocrit during cardiopulmonary bypass was independently associated with peak fractional change in creatinine [defined as the difference between the preoperative and peak postoperative creatinine represented as a percentage of the preoperative value]. A p value of less than 0.05 was considered significant. Multivariable analysis including preoperative hematocrit and other perioperative variables revealed that lowest hematocrit during cardiopulmonary bypass demonstrated a significant interaction with body weight and was highly associated with peak fractional change in serum creatinine [parameter estimate [PE] = 4.5; p 0.008] and also with highest postoperative creatinine value [PE = 0.06; p = 0.004]. Other renal risk factors were significant covariates in both models. These results add to concerns that current cardiopulmonary bypass management guidelines accepting extreme hemodilution may contribute to postoperative acute renal and other organ injury after cardiac surgery

Radial artery infection as a complication following radial cannulation in cardiac surgery

Radial artery infections secondary to catheterization for blood pressure monitoring are rare but potentially serious complications. The objective of the study was to evaluate the incidence, the risk factors and the evolution of radial artery infections following cardiac surgery. A retrospective review of 830 patients undergoing cardiac surgery between 2001 and 2003 at the National Heart Institute was undertaken. All patients with superficial radial artery infections, infected radial artery pseudoaneurysms, and arterial catheter-related bacteremia, were considered using prospective global surveillance of all nosocomial infections over the study period. Thirteen patients with radial infections were encountered [1.5%] with bacteremia occurring in 9 patients [1%] Five patients developed infected radial artery pseudoaneurysms [0.6%] and 5 patients developed subsequent sternal wound infections. Two patients died in their early postoperative evolution. Mean patient age was 67 years old and mean duration of cannulation was 5.8 days. Only 1 patient had diabetes. Seven of the 13 patients were positive for Staphylococcus aureus [54%]. All patients had undergone cardiopulmonary bypass for various procedures. All superficial infections responded well to antibiotic therapy. Early surgical intervention is essential in cases of infected radial artery pseudoaneurysms. Conclusions: The postoperative state and cardiopulmonary bypass put patients at risk for infectious complications. Strict systematic changing of arterial lines on a timely basis is unwarranted in our opinion. A high suspicion index, aggressive surgical treatment of bacterial arteritis and appropriate intravenous antibiotics are essential to improve the prognosis