Norman J. Starr

Morbidity and mortality risk associated with red blood cell and blood-component transfusion in isolated coronary artery bypass grafting

Objective:Our objective was to quantify incremental risk associated with transfusion of packed red blood cells and other blood components on morbidity after coronary artery bypass grafting. Design:The study design was an observational cohort study. Setting:This investigation took place at a large tertiary care referral center. Patients:A total of 11,963 patients who underwent isolated coronary artery bypass from January 1, 1995, through July 1, 2002. Interventions:None. Measurements and Main Results:Among the 11,963 patients who underwent isolated coronary artery bypass grafting, 5,814 (48.6%) were transfused. Risk-adjusted probability of developing in-hospital mortality and morbidity as a function of red blood cell and blood-component transfusion was modeled using logistic regression. Transfusion of red blood cells was associated with a risk-adjusted increased risk for every postoperative morbid event: mortality (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.67–1.87; p < .0001), renal failure (OR, 2.06; 95% CI, 1.87–2.27; p < .0001), prolonged ventilatory support (OR, 1.79; 95% CI, 1.72–1.86; p < .0001), serious infection (OR, 1.76; 95% CI, 1.68–1.84; p < .0001), cardiac complications (OR, 1.55; 95% CI, 1.47–1.63; p < .0001), and neurologic events (OR, 1.37; 95% CI, 1.30–1.44; p < .0001). Conclusions:Perioperative red blood cell transfusion is the single factor most reliably associated with increased risk of postoperative morbid events after isolated coronary artery bypass grafting. Each unit of red cells transfused is associated with incrementally increased risk for adverse outcome.

Perioperative determinants of morbidity and mortality in elderly patients undergoing cardiac surgery.

ObjectiveTo determine perioperative predictors of morbidity and mortality in patients ≥75 yrs of age after cardiac surgery. DesignInception cohort study. SettingA tertiary care, 54-bed cardiothoracic intensive care unit (ICU). PatientsAll patients aged ≥75 yrs admitted over a 30-month period for cardiac surgery. InterventionCollection of data on preoperative factors, operative factors, postoperative hemodynamics, and laboratory data obtained on admission and during the ICU stay. Measurements and Main ResultsPostoperative death, frequency rate of organ dysfunction, nosocomial infections, length of mechanical ventilation, and ICU stay were recorded. During the study period, 1,157 (14%) of 8,501 patients ≥75 yrs of age had a morbidity rate of 54% (625 of 1,157 patients) and a mortality rate of 8% (90 of 1,157 patients) after cardiac surgery. Predictors of postoperative morbidity included preoperative intraaortic balloon counterpulsation, preoperative serum bilirubin of >1.0 mg/dL, blood transfusion requirement of >10 units of red blood cells, cardiopulmonary bypass time of >120 mins (aortic cross-clamp time of >80 mins), return to operating room for surgical exploration, heart rate of >120 beats/min, requirement for inotropes and vasopressors after surgery and on admission to the ICU, and anemia beyond the second postoperative day. Predictors of postoperative mortality included preoperative cardiac shock, serum albumin of <4.0 g/dL, systemic oxygen delivery of <320 mL/min/m2 before surgery, blood transfusion requirement of >10 units of red blood cells, cardiopulmonary bypass time of >140 mins (aortic cross-clamp time of >120 mins), subsequent return to the operating room for surgical exploration, mean arterial pressure of <60 mm Hg, heart rate of >120 beats/min, central venous pressure of >15 mm Hg, stroke volume index of <30 mL/min/m2, requirement for inotropes, arterial bicarbonate of <20 mmol/L, plasma glucose of >300 mg/dL after surgery, and anemia beyond the second postoperative day. During the study period, the study cohort used 6,859 (21.5%) ICU patient-days out of a total 31,867 ICU patient-days. Nonsurvivors used 2,023 (30%) ICU patient-days and patients with morbidity used 5,903 (86%) ICU patient-days. ConclusionsSevere underlying cardiac disease (including shock, requirement for mechanical circulatory support, hypoalbuminemia, and hepatic dysfunction), intraoperative blood loss, surgical reexploration, long ischemic times, immediate postoperative cardiovascular dysfunction, global ischemia and metabolic dysfunction, and anemia beyond the second postoperative day predicted poor outcome in the elderly after cardiac surgery. Postoperative morbidity and mortality disproportionately increased the utilization of intensive care resources in elderly patients. Future efforts should focus on preoperative selection criteria, improvement in surgical techniques, perioperative therapy to ameliorate splanchnic and global ischemia, and avoidance of anemia to improve the outcome in the elderly after cardiac surgery. (Crit Care Med 1998; 26:225–235)

Effects of single dose, postinduction dexamethasone on recovery after cardiac surgery

BACKGROUND Corticosteroids have been recommended to facilitate rapid recovery after cardiac surgery. We previously reported that dexamethasone given after induction of anesthesia decreases the incidence of postoperative shivering. We performed a post hoc analysis of the data obtained during that study, focusing on secondary outcomes. METHODS A total of 235 adult patients undergoing elective coronary or valvular heart surgery were randomized to receive dexamethasone 0.6 mg/kg or placebo after induction of anesthesia. Patients who had pharmacologically treated diabetes mellitus, had hypersensitivity to dexamethasone, or were receiving treatment with corticosteroids were excluded. RESULTS We found that, compared with placebo, patients receiving dexamethasone were more likely to remain tracheally intubated for 6 hours or less (26.4% vs 10.0%, p = 0.020) and had a lower incidence of early postoperative fever (20.2% vs 36.8%, p = 0.009) and new-onset atrial fibrillation during the first 3 days postoperatively (18.9% vs 32.3%, p = 0.027). However, we could not demonstrate a statistical difference in the intensive care unit or hospital length of stay, or in overall morbidity and mortality. The dexamethasone-treated patients were also more likely to have a higher blood glucose on admission to the intensive care unit (186 mg/dL vs 143 mg/dL, p = 0.012). CONCLUSIONS Dexamethasone facilitates early tracheal extubation and is associated with a lower incidence of early postoperative fever and new-onset atrial fibrillation. Apart from a treatable decreased glucose tolerance, dexamethasone treatment was not shown to affect morbidity or mortality significantly.

LONG-TERM SURVIVAL AND FUNCTIONAL CAPACITY IN CARDIAC SURGERY PATIENTS AFTER PROLONGED INTENSIVE CARE

ObjectiveTo determine whether hospital discharge alone represents a good outcome for patients who had prolonged intensive care after cardiac surgery by studying their postdischarge survival and functional outcome. The secondary objective is to estimate the proportion of intensive care unit (ICU) resources used by the long-stay (≥10 initial consecutive ICU days) patients and to identify preoperative patient characteristics that are associated with a prolonged ICU stay and hospital and long-term survival. DesignInception cohort study. SettingThe Cleveland Clinic Foundation, a tertiary care, academic teaching institution. PatientsCardiac surgery patients with an initial ICU stay of 10 or more consecutive days. InterventionsData were collected daily during hospitalization on every adult who underwent coronary artery bypass graft and/or valve surgery at one institution in 1993. Discharged patients who spent >10 initial consecutive days in the ICU after surgery were contacted by telephone to determine vital status and functional capacity using the Duke Activity Status Index. Total ICU and total hospital direct costs were obtained for each patient. Measurements and Main ResultsThe primary outcome measurements were ICU length of stay, hospital mortality, after-surgery and postdischarge mortality and functional capacity, and relative resource utilization. Of the 2,618 cardiac surgery patients who met the inclusion criteria, 142 (5.4%) had an initial ICU length of stay of 10 or more consecutive days. Of these, 47 (33.1%) died in the hospital. Ninety-four of the 95 discharged patients were followed up (median follow-up, 30.6 months), and 44 of the 94 (46.8%) died during the follow-up period. The median Duke Activity Status Index for the 50 survivors was 26 out of a possible 58.2. The 142 long-stay patients used 50% of the total ICU days and 48% of the total ICU direct cost for all 2,618 patients. ConclusionsMany survivors of prolonged intensive care die soon after hospital discharge and many longer term survivors have a poor functional state. Therefore, hospital discharge is an incomplete measure of outcome for these patients, and longer follow-up is more appropriate. The relatively small number of patients who require prolonged intensive care consumes a disproportionate amount of the total ICU and total hospital direct cost.

ICU Admission Score for Predicting Morbidity and Mortality Risk After Coronary Artery Bypass Grafting

BACKGROUND This study was performed to develop an intensive care unit (ICU) admission risk score based on preoperative condition and intraoperative events. This score provides a tool with which to judge the effects of ICU quality of care on outcome. METHODS Data were collected prospectively on 4,918 patients (study group n = 2,793 and a validation data set n = 2,125) undergoing coronary artery bypass grafting alone or combined with a valve or carotid procedure between January 1, 1993, and March 31, 1995. Data were analyzed by univariate and multiple logistic regression with the end points of hospital mortality and serious ICU morbidity (stroke, low cardiac output, myocardial infarction, prolonged ventilation, serious infection, renal failure, or death). RESULTS Eight risk factors predicted hospital mortality at ICU admission, and these factors and five others predicted morbidity. A clinical score, weighted equally for morbidity and mortality, was developed. All models fit according to the Hosmer-Lemeshow goodness-of-fit test. This score applies equally well to patients undergoing isolated coronary artery bypass grafting. CONCLUSIONS This model is complementary to our previously reported preoperative model, allowing the process of ICU care to be measured independent of the operative care. Sequential scoring also allows updated prognoses at different points in the continuum of care.

Early onset of acute pulmonary dysfunction after cardiovascular surgery : Risk factors and clinical outcome

OBJECTIVE To define the incidence, risk factors, and clinical outcome of early pulmonary dysfunction after cardiovascular surgery for adults. STUDY Inception cohort. SETTING Adult cardiovascular intensive care unit (ICU). PATIENTS All adult admissions after cardiovascular surgery without preoperative pulmonary parenchyma or vascular disease over a period of 12 consecutive months. INTERVENTION Collection of data on demographics, preoperative organ insufficiency, emergency surgery, type of surgical procedure, cardiopulmonary bypass time, transfusion of blood products, postoperative arterial blood gases, and systemic hemodynamics on admission to the cardiovascular ICU. MEASUREMENTS AND MAIN RESULTS Early postoperative pulmonary dysfunction was defined by mechanical ventilation with a PaO2/FIO2 ratio of < or = 150 torr (< or = 20 kPa) and chest radiography on admission to the cardiovascular ICU. Secondary outcome included postoperative renal and neurologic dysfunction, nosocomial infections, length of mechanical ventilation, hospitalization, and death. A total of 3,122 patients were evaluated and 1,461 patients satisfied the entry criteria of the study. Early postoperative pulmonary dysfunction was present in 180 (12%) patients on admission to the cardiovascular ICU. Preoperative variables: age of > or = 75 yrs (odds ratio 1.69, 95% confidence interval [CI] 1.06 to 2.65), body mass index of > or = 30 kg/m2 (odds ratio 1.60, 95% CI 1.09 to 2.32), mean pulmonary arterial pressure of > or = 20 mm Hg (odds ratio 1.60, 95% CI 1.13 to 2.28), stroke volume index of < or = 30 mL/m2 (odds ratio 1.57, 95% CI 1.08 to 2.26), serum albumin (odds ratio 0.71, 95% CI 0.49 to 0.97), history of cerebral vascular disease (odds ratio 1.81; 95% CI 1.08 to 2.96); operative variables: emergency surgery (odds ratio 2.12, 95% CI 1.01 to 4.51), total cardiopulmonary bypass time of > or = 140 mins (odds ratio 1.54, 95% CI 1.0 to 2.34); and postoperative variables (on admission to cardiovascular ICU): hematocrit of > or = 30% (odds ratio 2.46, 95% CI 1.71 to 3.56), systemic mean arterial pressure of > or = 90 mm Hg (odds ratio 1.67, 95% CI 1.13 to 2.42), and cardiac index of > or = 3.0 L/min/m2 (odds ratio 2.09, 95% CI 1.44 to 3.01) were predictors of early postoperative pulmonary dysfunction. Pulmonary dysfunction was associated with a postoperative increase of serum creatinine (1.36 +/- 0.4 vs. 1.24 +/- 0.4 mg/dL, p < .02), neurologic complications (3% vs. 1.6%, p < .001), nosocomial infections (3% vs. 1.6%, p < .001), prolonged mechanical ventilation (2.2 +/- 5.9 vs. 1.7 +/- 5.6 days, p < .001), length of stay in the cardiovascular ICU (4.4 +/- 12.2 vs. 2.6 +/- 6.2 days, p < .001) and hospital (14.8 +/- 13.1 vs. 10.5 +/- 8.0 days, p < .001), and death (4.4% vs. 1.6%, p < .001). CONCLUSIONS The incidence of early postoperative pulmonary dysfunction is uncommon; however, once developed, it is associated with increased morbidity and mortality after cardiovascular surgery. Advanced age, large body mass index, preoperative increased pulmonary arterial pressure, low stroke volume index, hypoalbuminemia, history of cerebral vascular disease, emergency surgery, and prolonged cardiopulmonary bypass time are risk factors for early onset of severe pulmonary dysfunction after surgery. Postoperative hematocrit and systemic hemodynamics suggest that early postoperative pulmonary dysfunction can be a component of a generalized inflammatory reaction to cardiovascular surgery.

Clinical Characteristics of Preoperative Hypoalbuminemia Predict Outcome of Cardiovascular Surgery

OBJECTIVE To define the clinical characteristics and outcome of preoperative hypoalbuminemia in adult cardiovascular surgery. STUDY Inception cohort. SETTING Adult cardiovascular intensive care unit (CVICU). PATIENTS Admissions to CVICU between January 1 and December 31, 1993. INTERVENTION Preoperative hypoalbuminemia (serum albumin < or = 3.5 g/dL) was classified by the presence of malnutrition cachexia (body mass index of < or = 20 kg/m2), liver insufficiency (serum bilirubin > or = 2.0 mg/dL), history of congestive heart failure, or hypoalbuminemia alone. Demographics, chronic diseases, systemic hemodynamics, and laboratory data were obtained at preoperative and later on admission and during the stay in the CVICU. OUTCOME MEASURES Postoperative organ dysfunction, nosocomial infections, length of mechanical ventilation, hospitalization and death. RESULTS A total of 2,743 patients (91%) of 3,025 patients who were admitted to the CVICU were enrolled in the study. Preoperative hypoalbuminemia was found in 325 patients (12%): hypoalbuminemia and cachexia in 21 patients (6%), hypoalbuminemia and liver insufficiency in 26 patients (8%), hypoalbuminemia and history of congestive heart failure in 102 patients (31%), and hypoalbuminemia alone in 176 patients (54%). Clinical features of preoperative hypoalbuminemia were age > or = 75 years, female gender, left ventricular ejection fraction < or = 35%, hematocrit < or = 34%, serum creatinine > or = 1.9 mg/dL, systemic oxygen delivery < or = 350 mL/min.m2, acute stressful conditions (eg, infective endocarditis, acute myocardial infarction, or emergency surgery) and chronic obstructive pulmonary airway disease. Redo operations, combined valve and coronary artery bypass graft, mitral valve replacement, and thoracic aortic surgery were the commonest types of surgery performed in these patients. All types of hypoalbuminemia except for malnutrition cachexia increased the likelihood of postoperative organ dysfunction (cardiac, pulmonary, renal, hepatic, and neurologic), gastrointestinal bleeding, nosocomial infections, length of mechanical ventilation, stay in the CVICU, and hospital death. Cachectic hypoalbuminemia increased the requirement for postoperative parenteral nutrition and prolonged the length of stay in hospital. CONCLUSION Preoperative hypoalbuminemia was attributed to malnutrition cachexia, liver insufficiency or congestive heart failure in < 50% of cardiac patients undergoing cardiovascular surgery. All types of hypoalbuminemia except for malnutrition cachexia increased the likelihood of postoperative organ dysfunction, nosocomial infections, prolonged mechanical ventilation, and death. The morbidity and mortality attributed to hypoalbuminemia could be explained by the underlying clinical characteristics rather than malnutrition cachexia in cardiac patients.

Increased risk and decreased morbidity of coronary artery bypass grafting between 1986 and 1994

BACKGROUND The collective impact of advances in medical, surgical, and anesthetic care on the characteristics and outcomes of patients who undergo coronary artery bypass grafting was assessed. METHODS We compared the demographic and clinical characteristics, preoperative risk factors, morbidity, and mortality of two groups of patients who underwent coronary artery bypass grafting in isolation or in combination with other procedures between July 1, 1986, and June 30,1988 (group 1, n = 5,051), and between January 1, 1993, and March 31, 1994 (group 2, n = 2,793). The patients were stratified according to their preoperative risk level. Outcome measures consisted of changes in preoperative risk categories; hospital mortality rates; overall and risk-adjusted major cardiac, neurologic, pulmonary, renal, and septic morbidity rates; and intensive care unit length of stay. RESULTS Changes in the distribution of risk categories, from a median of 2 to 4 on a 9-point scale (p < 0.001), indicated that patients in group 2 were at significantly higher risk than those in group 1. The risk-adjusted mortality rate did not change (2.8% to 2.9%; p = 0.15), but the risk-adjusted morbidity rate decreased significantly (14.5% to 8.8%; p < 0.001). CONCLUSIONS At our institution, patients who undergo coronary artery bypass grafting are now at greater preoperative risk at the time of hospital admission. However, their morbidity rate is significantly lower and their mortality rate is unchanged, results that we attribute to the collective impact of changes in our medical and surgical procedures.

Intraoperative echocardiography is indicated in high-risk coronary artery bypass grafting

BACKGROUND Intraoperative echocardiography is a valuable monitoring and diagnostic technology used in cardiac surgery. This reports our clinical study of the usefulness of intraoperative echocardiography to both surgeons and anesthesiologists for high-risk coronary artery bypass grafting. METHODS From March to November 1995, 82 consecutive high-risk patients undergoing coronary artery bypass grafting were studied in a four-stage protocol to determine the efficacy of intraoperative echocardiography in management planning. Alterations in surgical and anesthetic/hemodynamic management initiated by intraoperative echocardiography findings were documented in addition to perioperative morbidity and mortality. RESULTS Intraoperative echocardiography initiated at least one major surgical management alteration in 27 patients (33%) and at least one major anesthetic/hemodynamic change in 42 (51%). Mortality and the rate of myocardial infarction in this consecutive high-risk study population using intraoperative echocardiography and in a similar group of patients without the use of intraoperative echocardiography was 1.2% versus 3.8% (not significant) and 1.2% versus 3.5% (not significant), respectively. CONCLUSIONS We conclude that when all of the isolated diagnostic and monitoring applications of perioperative echocardiography are routinely and systematically performed together, it is a safe and viable tool that significantly affects the decision-making process in the intraoperative care of high-risk patients undergoing primary isolated coronary artery bypass grafting and may contribute to the optimal care of these patients.

Association between postoperative hypothermia and adverse outcome after coronary artery bypass surgery

BACKGROUND We examined the effect on outcome of mild hypothermia (< 36 degrees C) upon intensive care unit (ICU) admission on patient outcome after coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). METHODS We performed a retrospective database analysis of 5,701 isolated CABG patients requiring CPB, operated upon from January 1995 to June 1997. Patients were classified as either hypo- (< 36 degrees C) or normothermic (> or = 36 degrees C) upon ICU admission. ICU admission bladder core temperature (BCT) versus outcome was evaluated. Outcome measures included mortality, resource utilization (mechanical ventilation time, ICU and hospital length of stay, and postoperative packed red blood cell transfusion), and major morbidity (cardiac, renal, neurologic, or major infection). RESULTS Overall, patients admitted to the ICU with BCT < 36 degrees C had a significantly greater mortality (p = 0.02), prolonged mechanical ventilation (p = 0.007), packed red blood cell transfusion (p = 0.001), ICU (p = 0.01), and hospital (p = 0.005) length of stay. CONCLUSIONS BCT of less than 36 degrees C, upon ICU admission, has a significant association with adverse outcome after CABG with CPB. M An __ Tl QA_7_t-0