Variation in arterial inflow temperature: a regional quality improvement project.

Peer-reviewed evidence (Class IIa, Level B) suggests that arterial blood temperature should be limited to 37 degrees C during cardiopulmonary bypass. We implemented a regional quality improvement initiative to reduce regional variability in our performance around this recommendation at four northern New England medical centers between January 2006 and June 2010. Cardiovascular perfusionists at four medical centers collaborated by conference calls regarding blood temperature management. Evidence from the recommendations were reviewed at each center, and strategies to prevent hyperthermia and to improve performance on this quality measure were discussed. Centers submitted data concerning highest arterial blood temperatures among all isolated coronary artery bypass grafting procedures between 2006 through June 2010. Scope and focus of local practice changes were at the discretion of each center. The timing of each center's quality improvement initiatives was recorded, and adherence to thresholds of 37 degrees C and 37.5 degrees C were analyzed. Data were collected prospectively through our regional perfusion registry. Data were available for 4909 procedures (1645 before interventions, 3264 after interventions). Prior to the quality improvement interventions, 90% of procedures had elevated arterial line temperatures (37 degrees C or more), and afterwards it was 69% (p < .001) for an absolute difference of 21%. Prior to the intervention, 53% of procedures had temperatures beyond a threshold of 37.5 degrees C versus 19% subsequent to interventions, for an absolute difference of 34% (p < .001). This regional effort to reduce patient exposure to elevated arterial line temperatures resulted in a significant sustained reduction in high arterial outflow temperatures at three of the four centers. A regional registry provides a means for assessing performance against evidence-based recommendations, and evaluating short and long-term success of quality improvement initiatives.

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.

Highest core temperature during cardiopulmonary bypass and rate of mediastinitis.

Temperature control during cardiopulmonary bypass (CPB) may be related to rates of bacterial infection. We assessed the relationship between highest core temperature during CPB and rates of mediastinitis in 6955 consecutive isolated coronary artery bypass graft (CABG) procedures in northern New England. The overall rate of mediastinitis was 1.1%. The association between highest core temperature and mediastinitis was different for diabetics than for nondiabetics. A multivariate model showed that there was a significant interaction between diabetes and temperature in their association with mediastinitis (p=0.015). Diabetic patients showed higher rates of mediastinitis as highest core temperature increased, from 0.7% in the < or = 37 degrees C group to 3.3% in the > or = 38 degrees C group (p(trend) = 0.002). Adjusted rates were similar. Nondiabetic patients did not show this trend (p(trend) = 0.998). Among diabetic patients, a peak core body temperature > 37.9 degrees C during CPB is a significant risk factor for development of mediastinitis. Avoidance of higher temperatures during CPB may lower the risk of mediastinitis for diabetic patients undergoing CABG surgery.

Lowest core body temperature and adverse outcomes associated with coronary artery bypass surgery.

To examine the effect of lowest core body temperature on adverse outcomes associated with coronary artery bypass graft (CABG) surgery, data were collected on 7134 isolated CABG procedures carried out in New England from 1997 to 2000. Excluded from the analysis were patients with pump times < 60 and > 120 min and those operated upon using continuous warm cardioplegia. Data for lowest core temperature were divided into quartiles for analysis ( < 31.4 degrees C, 31.5-33.1 degrees C, 33.2-34.3 degrees C, and 2 34.4 degrees C). Patients with lower core body temperature on cardiopulmonary bypass (CPB) had higher in-hospital mortality rates. Crude mortality rates were 2.9% in the < or = 31.4 degrees C group, 2.1% in the 31.5-33.1 degrees C group, 1.3% in the 33.2-34.3 degrees C group and 1.2% in the > or = 34.4 degrees C group. The trend toward higher mortality as core temperature decreased was statistically significant (P(trend) < 0.001). Adjustment for differences in patient and disease characteristics did not significantly change the results and the test of trend remained significant (p < 0.001). Rates of perioperative stroke were somewhat lower in the colder groups. Rates in the two colder groups were 0.9% compared with 1.6% and 1.4% in the warmer groups (P(trend) = 0.082). This remained a marginal but significant trend after adjustment for possible confounding factors (p = 0.044). Low core body temperatures on CPB are associated with higher rates of in-hospital mortality among isolated CABG patients. Rates of intra- or postoperative use of an intra-aortic balloon pump are also higher with lower core temperatures. We concluded that temperature management strategy during CABG surgery has an important effect on patient outcomes.