The association of perioperative red blood cell transfusions and decreased long-term survival after cardiac surgery.

BACKGROUND: Exposure to red blood cell (RBC) transfusions has been associated with increased mortality after cardiac surgery. We examined long-term survival for cardiac surgical patients who received one or two RBC units during index hospitalization. METHODS: Nine thousand seventy-nine consecutive patients undergoing coronary artery bypass graft, valve, or coronary artery bypass graft/valve surgery at eight centers in northern New England during 2001-2004 were examined after exclusions. A probabilistic match between the regional registry and the Social Security Administration's Death Master File determined mortality through June 30, 2006. Cox Proportional Hazard and propensity methods were used to calculate adjusted hazard ratios. RESULTS: Thirty-six percent of patients (n = 3254) were exposed to one or two RBC units. Forty-three percent of RBCs were given intraoperatively, 56% in the postoperative period and 1% were preoperative. Patients transfused were more likely to be anemic, older, smaller, female and with more comorbid illness. Survival was significantly decreased for all patients exposed to 1 or 2 U of RBCs during hospitalization for cardiac surgery compared with those who received none (P < 0.001). After adjustment for patient and disease characteristics, patients exposed to 1 or 2 U of RBCs had a 16% higher long-term mortality risk (adjusted hazard ratios = 1.16, 95% CI: 1.01-1.34, P = 0.035). CONCLUSIONS: Exposure to 1 or 2 U of RBCs was associated with a 16% increased hazard of decreased survival after cardiac surgery.

Cardiopulmonary bypass recommendations in adults: the northern New England experience.

Using a regional cardiopulmonary bypass (CPB) registry, we compared the practice of CPB at eight northern New England institutions to recently published recommendations. We examined CPB practice among 3597 adult patients undergoing isolated coronary artery bypass grafting surgery from January 2004 to June 2005. Registry variables were used to compare regional CPB practice to recommendations on topics of neurologic protection (pH management, avoidance of hyperthermia, minimizing return of pericardial suction blood, aortic assessment, arterial line filtration), maintenance of euglycemia, reduction of hemodilution, and attenuation of the inflammatory response. We report overall regional practice (regional minimum, maximum). All centers used alpha-stat pH management and arterial line filters. Avoidance of hyperthermia (temperature < 37degrees C) was achieved during 23.4% of procedures (regional minimum, 1.5%; maximum, 83.2%). Minimizing return of pericardial suction blood was achieved in 23.7% of cases (0.7%, 93.6%). Aortic assessment was performed during 45.7% of procedures (1.3%, 98.9%). Maintenance of euglycemia (< 200 mg/dL) was accomplished in 82.7% (57.1%, 97.9%) of cases. Hemodilution (hematocrit < 23% on CPB) was lower for men 32.4% (20.6%, 52.3%) than women 77.9% (64.7% 88.9%). Men were less likely to receive red blood cell transfusions in the operating room (11.0%; 1.8%, 20.9%) than women (54.6%; 30.1%, 70.6%). In an effort to attenuate the inflammatory response, surface coated circuits were used in 83.3% of procedures (8.8%, 100%). During this time, gaps existed between regional CPB practice and recently published recommendations. We continue to prospectively measure CPB practice relating to these recommendations to monitor and improve the care provided to our patients.

Unique considerations for the spinal cord injured patient undergoing cardiac surgery utilizing cardiopulmonary bypass.

A 37-year-old male with mitral valve regurgitation presented for mitral valve replacement. He has been a C5 quadriplegic for 13 years. The patient had been discharged 2 months before to this admission after a complicated hospital course for Staphylococcus aureus infection of the left hip. His course was complicated by adult respiratory distress syndrome (ARDS) requiring prolonged intubation, acute renal failure (ARF) requiring dialysis, 10-day coma, and bacterial endocarditis now requiring mitral valve replacement. After initial stabilization with antibiotics and gradual improvement of the multiorgan system failure, the patient presented for valve replacement and worsening congestive heart failure (CHF). Para- and quadriplegic patients rarely undergo cardiac surgery requiring cardiopulmonary bypass (CPB). The explanation for this low incidence of heart surgery in this patient population ranges from physiologic changes from the spinal cord injury to their relatively short life span. Therefore, there is no vast knowledge of how these patients with spinal cord injury will physiologically respond to CPB. Chronic paraplegia presents unique anesthetic and perfusion challenges. General anesthesia for a patient with prolonged spinal cord damage can be difficult because of dysreflexia, muscle wasting, and potassium changes with depolarizing muscle relaxants. For the perfusionist, chronic paraplegia also accentuates hemodynamic responses to nonpulsatile flow with low peripheral vascular resistance common and difficult to treat. Dramatic increases in circulating catecholamine levels are a secondary result of the initiation of CPB that can cause a hypo- and hypertensive state. Depending on the level of spinal cord injury, one might expect acute hypo- or hypertension with the various phases of open-heart surgery and CPB. A viscous circle may occur because the hypertensive state is exaggerated because of inhibitory signals not passed below the spinal cord lesion and, therefore, the vasoconstrictive reflex continues unabated. The attack usually occurs abruptly and can lead to cerebrovascular hemorrhage and death if not controlled. Fortunately, we found this patient did not develop mass autonomic dysreflexia and was not difficult to wean from CPB. The problems associated with spinal cord injury present potential complications to this patient population. Numerous triggering mechanisms may lead to a variety of clinical complications. Consideration of a response/ treatment management plan for potential problems must be exercised by the surgical team.