Preoperative Mortality Risk Research Articles

Storage age of transfused platelets and outcomes after cardiac surgery

The relationship between duration of platelet (PLT) storage, currently limited to 5days, and surgical outcomes has not been established. We tested the hypothesis that PLT storage age was associated with adverse outcomes. A retrospective cohort of aortocoronary bypass (CABG) surgery patients from January 1996 to January 2005 receiving one or more PLT transfusions was selected for study. The composite primary ("short-term") outcome was 30-day mortality or prolonged hospital stay. Secondary outcomes included complications and survival to annual follow-up. Multivariable logistic regression models and Cox proportional hazards regression analysis evaluated the association between PLT storage age and outcomes, expressed as an odds ratio (OR) or hazard ratio with 95% confidence intervals (CIs), respectively. PLT transfusion was administered to 3272 of 10,275 CABG patients and 2578 received units of known storage age, which ranged between 2 and 5days (median, 4days; 25th percentile, 3days; 75th percentile, 5 days). The mortality rate for the 1637 patients receiving a single plateletpheresis transfusion was 3.8%, while 21.6% experienced a prolonged hospital stay or death. After adjusting for the number of PLT and red blood cell (RBC) units transfused, RBC storage age, and preoperative mortality risk, there was no association between PLT storage age and short-term outcome (OR, 1.01; 95% CI, 0.90-1.14), survival (hazard ratio [HR], 1.04; 95% CI, 0.96-1.13), or postoperative infections. PLT storage age was not associated with adverse short-term outcomes, decreased long-term survival, or infections after cardiac surgery.

Impact of INTERMACS and Composite Preoperative Mortality Risk Score Stratification on Survival in Patients Receiving Heart Mate II LVAD as Bridge to Transplantation

Introduction: Patients undergoing cardiac bridge to transplantation (BTT) with HeartMate II (HMII) implantation can be stratified according to INTERMACS score, Right Ventricular Failure Risk Score (RVFRS), and composite pre-operative mortality risk scores, which allow improved patient selection for Left Ventricular Assist Device (LVAD) implantation and possible prediction of patient survival postoperatively. Hypothesis: High risk INTERMACS scores, RVFRS, and composite preoperative mortality risk scores may confer lower survival in our patient population implanted with HM II LVAD as BTT.

Prehospital Treatment of Infrarenal Ruptured Abdominal Aortic Aneurysms: A Multicentric Analysis

The aim of this study was to evaluate the quality of the current treatment of patients presenting with ruptured abdominal aortic aneurysms (RAAAs), from the first symptoms to the operating room with an analysis of preoperative mortality risk factors. For 3 years, in four vascular surgery departments, we have collected all the consecutive cases of patients operated on for RAAA. We analyzed the initial clinical situation, the means of transportation, the time elapsed before treatment, and the mortality rate at 3 days. Sixty-six RAAAs were operated on. Mean patient age was 76 years (range, 52-93 years). The initial symptoms were a precisely located pain either abdominal (45.3%), lumbar (17.2%), or both (14.1%) or feeling faint (10.9%). In 22.7% of the cases, an initial hemodynamic instability was observed. In 46.8% of the cases, patients first went to a peripheral hospital before being admitted into a referral centre. In 84.5% of the cases, medical mean of transportation was used. The mean distance covered was 59.8 kilometers (range, <5 km to 213 km). The initial diagnosis was accurate in 67.3% of the cases. The mean intrahospital waiting period between the arrival at a reference center and the admission into an operating room was 127 minutes. Global mortality rate was 44.2%. The main preoperative mortality factor to be noticed was the initial hemodynamic instability (p=0.0031). Among stable patients, only two of them (5.4%) worsened during the preoperative treatment. In our study, hemodynamic instability corresponds to the main prognosis factor of mortality. In most cases, the initial stability persisted and allowed additional evaluation. However, the intrahospital waiting periods appeared to be too long. To be optimal, the adequate treatment should be specifically designed as soon as a diagnosis has been established.

Stroke-Related Mortality in Coronary Surgery Is Reduced by the Off-Pump Approach

Stroke remains an important complication after coronary artery bypass graft surgery (CABG). We sought to determine the frequency and death-related incidence of stroke after on-pump and off-pump CABG. We analyzed 4,869 consecutive isolated CABG performed in our institution. Of these, 3,490 (71.7%) were off-pump and 1,379 (28.3%) were on-pump. Propensity matched samples of 1,379 off-pump and 1,379 on-pump were compared on clinical presentation and The Society of Thoracic Surgeons (STS) predicted scores for risk of postoperative mortality and stroke. Univariate analyses were used to compare the relationship of off-pump and on-pump groups to postoperative mortality and stroke. Multivariate logistic regression was used to determine the unique association between all variables and occurrence of mortality after stroke. No differences were found for sex, diabetes mellitus, history of renal failure, prior stroke, or timing of surgery. Postoperative mortality occurred in 75 patients (2.7%) and stroke in 47 (1.7%). The off-pump patients had a lower rate of stroke (1.0% versus 2.4%; p < 0.01) compared with on-pump patients. Mortality after stroke occurred in 14 patients, with a lower rate occurring in the off-pump group (14.3% versus 36.4%; p = 0.07). Multivariate analyses controlling for the effect of preoperative risk factors and STS mortality risk demonstrated that off-pump status was independently associated with an 84% decrease in the risk of death after stroke (adjusted odds ratio 0.157, 95% confidence interval: 0.035 to 0.711, p = 0.016). Off-pump CABG is associated with lower stroke rates and stroke-related mortality. It may be useful to consider off-pump CABG for patients who are at higher risk for postoperative stroke.

Thirty-day NSQIP database outcomes of open versus endoluminal repair of ruptured abdominal aortic aneurysms

The mortality of ruptured abdominal aortic aneurysm (rAAA) has decreased 3.5% per decade in the last 50 years to a current rate of 40%-50%. Reports have indicated that endovascular repair (EVAR) is feasible for rAAA and may offer potential benefits over open repair. We examined the National Surgical Quality Improvement Program (NSQIP) database to compare 30-day multicenter outcomes for EVAR vs open rAAA repair. Patients that underwent rAAA repair in the NSQIP database from 2005 to 2007 were identified through a combination of Current Procedural Terminology (CPT) codes and International Classification of Diseases-Ninth Revision (ICD-9) diagnoses. Preoperative comorbidities, operative duration and transfusion, and 30 day outcomes were evaluated using t tests or Chi-squared tests depending on the variable. A separate multivariable regression was performed for each outcome adjusting for all independently predictive preoperative and intraoperative risk factors. A total of 427 patients were identified and 76.8% of patients underwent open repair. The open repair groups exhibited lower albumin levels and higher percentage of patients with preoperative hematocrit (Hct) <38% and need for preoperative ventilation. The requirement for preoperative blood transfusion was similar. Patients undergoing open repair had much higher intraoperative transfusion requirements (11.8 +/- 8.9 vs 4.2 +/- 6.0 red blood cell units, P < .001). After adjustment for preoperative mortality risk factors, the mortality risk was higher for open repair versus EVAR (odds ratio 1.67, 95% confidence interval [CI] 0.91-3.05, P = .096) but did not reach significance. After similar adjustment the composite morbidity odds ratio for open repair versus EVAR was 1.82 (95% CI 1.11-2.99, P = .018) and the pulmonary adverse events odds ratio was 1.99 (95% CI 1.22-3.25, P = .006). Risks for the other outcomes were not significant. Composite 30-day morbidity risk is lower after EVAR vs open repair of rAAA. Open repair is associated with increased transfusion requirements. Performance of EVAR in rAAA patients with favorable anatomy could potentially result in improved outcome as compared with open repair.

Preoperative risk factors for mortality after relaparotomy: analysis of 254 patients

The aim of this work was to analyze preoperative mortality risk factors after relaparotomy for abdominal surgery in a unit of General Surgery at a University Hospital. A total of 314 relaparotomies in 254 patients were performed between February 2004 and February 2008. We analyzed data about past medical history, first operation, as well as clinical and biochemical parameters previous to reoperation. Indications for relaparotomy were peritonitis, bleeding, abscess, exploratory laparotomy, and evisceration. Overall mortality was 22%. Mortality of the patients with a single relaparotomy was 20% vs. 44% if they were reoperated upon twice. Mortality was associated with age, past history of cardiovascular disease, active neoplasm, previous treatment with platelet anti-aggregant drugs, first surgery American Society of Anesthesia score, and the presence of an anastomosis. Preoperative data associated with mortality were the number of systemic inflammatory response syndrome criteria, suture dehiscense, ileus, positive blood cultures, mechanical ventilation, artificial nutrition, antibiotics or vasoactive drugs, tachycardia, and abnormal body temperature. High white blood cell count or bilirrubin levels and low albumin or prothrombin time were also associated with mortality. Multivariate logistic regression analysis isolated age (P = 0.02), abnormal body temperature (P = 0.02), and the need of mechanical ventilation (P = 0.004) as independent preoperative variables predictive for mortality after relaparotomy. Advanced age, the presence of either fever or hypothermia, and the need of mechanical ventilation are preoperative risk factors associated with mortality after relaparotomy and should be considered when planning reintervention.

An Australian risk prediction model for 30-day mortality after isolated coronary artery bypass: The AusSCORE

Our objective was to identify risk factors associated with 30-day mortality after isolated coronary artery bypass grafting in the Australian context and to develop a preoperative model for 30-day mortality risk prediction. Preoperative risk associated with cardiac surgery can be ascertained through a variety of risk prediction models, none of which is specific to the Australian population. Recently, it was shown that the widely used EuroSCORE model validated poorly for an Australian cohort. Hence, a valid model is required to appropriately guide surgeons and patients in assessing preoperative risk. Data from the Australasian Society of Cardiac and Thoracic Surgeons database project was used. All patients undergoing isolated coronary artery bypass grafting between July 2001 and June 2005 were included for analysis. The data were divided into creation and validation sets. The data in the creation set was used to develop the model and then the model was validated in the validation set. Preoperative variables with a P value of less than .25 in chi(2) analysis were entered into multiple logistic regression analysis to develop a preoperative predictive model. Bootstrap and backward elimination methods were used to identify variables that are truly independent predictors of mortality, and 6 candidate models were identified. The Akaike Information Criteria (AIC) and prediction mean square error were used to select the final model (AusSCORE) from this group of candidate models. The AusSCORE model was then validated by average receiver operating characteristic, the P value for the Hosmer-Lemeshow goodness-of-fit test, and prediction mean square error obtained from n-fold validation. Over the 4-year period, 11,823 patients underwent cardiac surgery, of whom 65.9% (7709) had isolated coronary bypass procedures. The 30-day mortality rate for this group was 1.74% (134/7709). Factors selected as independent predictors in the preoperative isolated coronary bypass AusSCORE model were as follows: age, New York Heart Association class, ejection fraction estimate, urgency of procedure, previous cardiac surgery, hypercholesterolemia (lipid-lowering treatment), peripheral vascular disease, and cardiogenic shock. The average area under the receiver operating characteristic was 0.834, the P value for the Hosmer-Lemeshow chi(2) test statistic was 0.2415, and the prediction mean square error was 0.01869. We have developed a preoperative 30-day mortality risk prediction model for isolated coronary artery bypass grafting for the Australian cohort.

Benefits of the Preemptive Intra-Aortic Balloon Pump: An Audit of Practice in a Regional Cardiothoracic Center

Recent evidence suggests that preemptive use of an intra-aortic balloon pump (IABP) is associated with better outcomes in high-risk patients undergoing cardiac surgery. This retrospective study compares preemptive (planned) use of the IABP to emergency (unplanned) use in a regional cardiothoracic center. All patients who required an IABP from February 2003 to June 2006 were identified from theater records. The collected data included patient demographics, preoperative state, operative details, morbidity due to the IABP, and operative mortality. Patients were divided into 2 groups: planned use (preoperative plus elective intraoperative) and unplanned use (postoperative plus emergency intraoperative). Preoperative mortality risk was calculated with the logistic EuroSCORE. We identified 135 patients (75% male). There were no significant differences between the groups with respect to age, preoperative state, operation type, logistic EuroSCORE, or myocardial ischemia time. The 2 groups showed a significant difference in mortality: planned IABP insertion, 17%; unplanned insertion, 45% (P = .001). A multivariate analysis of the study population showed the logistic EuroSCORE (odds ratio, 0.974; 95% confidence interval, 0.950-0.998; P = .035) and timing of IABP use (odds ratio, 4.728; 95% confidence interval, 1.932-11.566; P = .001) to be independent predictors of mortality. Preemptive use of the IABP in this patient cohort was associated with a 50% advantage in mortality compared with emergency IABP use. The logistic EuroSCORE may be used preoperatively to guide IABP use. Complications are rare and can be treated successfully. The risk-to-benefit ratio of preemptive IABP use is low in this cohort of patients.

Patient selection for minimally invasive aortic valve implantation

We have read with great interest the two original articles in the January issue of the Journal that report early experiences with transapical aortic valve replacement [1,2]. These studies show that beating-heart transapical aortic valve implantation has acceptable early results in patients deemed to be at too high a risk to allow for a safe valve replacement by conventional surgery. The authors of both studies should be celebrated as innovators and congratulated for their pioneering efforts using these novel technologies. In these studies, transapical procedures were reserved for patients with preoperative risk profiles that were deemed to be prohibitive for traditional valve replacement such that a successful outcome following conventional surgery was considered unlikely. However, precise inclusion criteria and a definition of inoperability were not provided in these papers. The lack of a transparent patient selection process makes these studies difficult to interpret and compromises the reader’s ability to get a sense of the role of these interventions in the management of severe aortic stenosis. Furthermore, we are concerned that much of the preoperative risk stratification in these studies relied on the logistic EuroSCORE. Predictive models including the EuroSCORE have previously been shown to lose discriminatory capability at the extremes of risk [3,4]. To illustrate our point, we have reviewed all consecutive patients undergoing aortic valve replacement at our institution over a 10-year period (1995—2005). The population evaluated included a total of 1879 consecutive patients. During that time period, there were 325 patients, with a logistic EuroSCORE of greater than 20%, who underwent conventional aortic valve surgery. The average predicted mortality for that group was 39.4% by logistic EuroSCORE. In contrast, we have found in this high-risk group of patients that the observed in-hospital mortality was only 15.1%, which was significantly lower than what was predicted. Therefore, relying on the EuroSCORE to predict preoperative mortality risk may inappropriately classify patients as high-risk patients and unsuitable for conventional aortic valve replacement. Taken further, this may mean that some patients with high EuroSCORE could be denied an intervention that can potentially benefit them. These studies [1,2] are early feasibility studies and are not randomized controlled trials evaluating two potentially equivalent and equally acceptable interventions. The investigators should interpret their results accordingly and not overstate their conclusions by reporting that this technology is a ‘viable alternative’ to conventional surgical aortic valve replacement [2]. The issue here is one of good science and not the reluctance to accept an emerging technique.

Risk-adjusted analysis of early mortality after ruptured abdominal aortic aneurysm repair

Ruptured abdominal aortic aneurysms (RAAAs) continue to result in early mortality in up to 50% of patients. Additionally, it remains difficult to compare outcomes given the variability in patient comorbidities and presentation. The purpose of this study was to describe an instrument that permits the prospective analysis of outcomes after RAAA repair while adjusting for the variability in preoperative risk. Consecutive patients undergoing attempted open RAAA repair over a 5-year period (1999 to 2003) at our center were reviewed. Thirty-day or in-hospital mortality was the main outcome variable. Preoperative mortality risk was estimated for each patient by using a validated modification of the POSSUM scoring system (V-POSSUM). A risk-adjusted cumulative sum method (RA-CUSUM) was used to compare observed versus predicted outcomes by assigning a risk-adjusted score, based on log-likelihood ratios, to each patient. These scores were sequentially plotted with preset control limits to allow for "signaling" when results were substantially different from expected (doubling or halving of odds ratios). A total of 136 patients were reviewed, with an early mortality rate of 45.6%. V-POSSUM scores were accurate in predicting mortality for the entire cohort, with an observed-to-predicted mortality ratio of 0.92 (P = .80). Each patient's risk-adjusted score was plotted sequentially. In one segment of the resulting plot, the graph adopted a negative slope and crossed the lower control limit, indicating improved results compared with predicted. V-POSSUM scores in this series accurately predicted early mortality after RAAA surgery. The RA-CUSUM method allows for the prospective evaluation of outcomes, while taking into account patient variability. In the current study, this resulted in the identification of a series of patients who had improved outcomes compared with predicted.

Multiple Risk Assessment of Cardiovascular Surgery in Chronic Renal Failure Patients

Chronic renal failure is a major risk factor in cardiovascular surgery. We evaluated results of cardiovascular surgery in chronic renal failure patients (s-creatinine > 200 micromol/L or established dialysis) at our center from 1990 to 2000. One hundred and six chronic renal failure patients underwent cardiovascular surgery (56 coronary artery bypass operations, 25 valve replacements with or without coronary bypass, and 25 other major cardiovascular operations [8 thoracic aorta, 10 abdominal aorta, 7 other]). Matched controls were selected (n = 106) based on age, sex, year, and type of operation and occurrence of diabetes. There were 88 men and 18 women and mean age was 64 +/- 10 years (standard deviation). Demographics did not differ between chronic renal failure and control patients, except for hypertension (more prevalent in chronic renal failure group, p < 0.05). Intraoperative hemorrhage, perfusion and ischemia time, and reoperation did not differ between groups. Chronic renal failure patients received more transfusions of red blood cells, plasma, and platelets (p < 0.02). Ventilation support (27.6 +/- 59.3 hours), intensive care unit stay (7.7 +/- 8.3 days), and hospital stay (12.3 +/- 10.5 days) were longer (p < 0.02). Early mortality was 16% versus 6.6% (p = 0.04) and 5-year mortality was 79% versus 39% (p < 0.05) for chronic renal failure and control patients, respectively. Independent preoperative risk factors of mortality for chronic renal patients were age greater than 70 years (relative risk = 2.32, p = 0.001), chronic obstructive pulmonary disease (relative risk = 2.59, p = 0.001), diabetes (relative risk = 1.80, p = 0.037), and dialysis (relative risk = 2.03, p = 0.005). Chronic renal failure patients suffered more postoperative complications and had substantially increased short-term and long-term mortality rates. Independent preoperative mortality risk factors for chronic renal failure patients were age, chronic obstructive pulmonary disease, diabetes, and chronic dialysis.

Risk-Adjusted Analysis of Outcomes Following Elective Open Abdominal Aortic Aneurysm Repair

The purpose of this study was to describe a method to analyze outcomes following open abdominal aortic aneurysm (AAA) repair while considering the variability in patients' preoperative risk. Consecutive patients undergoing elective open infrarenal AAA repair during a 4-year period (2000-2003) were reviewed. Thirty-day or in-hospital mortality was the major outcome variable. Preoperative mortality risk was estimated for each patient using a validated scoring system that considers age, renal dysfunction, and coronary artery and cerebrovascular disease. A risk-adjusted cumulative sum method was used to compare observed versus predicted outcomes by assigning a risk-adjusted score, based on log-likelihood ratios, to each patient. These cumulative scores were sequentially plotted with preset control limits to allow for "signaling" when results were substantially different than expected (doubling or halving of odds ratios). Four hundred and sixty-three patients were studied with an overall early mortality rate of 4.5% (n = 21). Patients were allocated to three different preoperative risk groups (low, n = 89; medium, n = 160; high, n = 214) according to a medical comorbidity-based scoring system. Predicted (P) and observed (O) mortality rates for each group were as follows: low, 2.4% (P) and 2.2% (O); medium, 4.1% (P) and 4.4% (O); high, 9.3% (P) and 5.6% (O). The resulting risk-adjusted scores for each patient were plotted sequentially. This plot was flat for the first year and then adopted a negative slope crossing the lower control limit after 266 patients, indicating improved results compared to those expected. This coincided with the adoption of routine intraoperative cell saver use in our practice. This form of analysis allows for the prospective evaluation of results while considering patient-mix variabilities.

Outcomes and perioperative hyperglycemia in patients with or without diabetes mellitus undergoing coronary artery bypass grafting

Background The association between perioperative hyperglycemia and outcomes in patients with and without diabetes mellitus undergoing coronary artery bypass grafting is not well defined. We measured the association between perioperative hyperglycemia and outcomes among patients undergoing coronary artery bypass grafting. Methods We report a historic cohort study of 1574 patients who had undergone coronary artery bypass grafting between 1998 and 1999, 545 (34.6%) with diabetes. Perioperative blood glucose level was defined as the average of all blood glucose tests obtained on the day of and the day after surgery. Outcomes were 30-day mortality, infection rates (sternum, harvest site, sepsis, pneumonia, urinary tract), and resource utilization. Results After adjusting for diabetes status and calculated preoperative mortality or mediastinitis risk scores, each 50 mg/dL (2.78 mmol/L) blood glucose increase was not statistically associated with higher mortality (odds ratio 1.37; 95% confidence interval, 0.98 to 1.92; p = 0.07), or higher infection rate (odds ratio 1.23, 95% confidence interval 0.94 to 1.60; p = 0.14). Each 50 mg/dL blood glucose increase was associated with longer postoperative days by 0.76 days (95% confidence interval 0.36 to 1.17 days; p < 0.001), increased hospitalization charges by $2824 (95% confidence interval $1599 to $4049; p < 0.001), and increased hospitalization cost by $1769 (95% confidence interval $928 to $2610; p < 0.001). In the unadjusted analysis, infections occurred more frequently in patients with diabetes (6.6% vs 4.1%, p = 0.03). Conclusions Perioperative hyperglycemia is associated with increased resource utilization in patients undergoing coronary artery bypass grafting with and without diabetes.

Evolution of case-mix in heart surgery: from mortality risk to complication risk.

During the last two decades despite an increase of the average preoperative mortality risk of patients referred to heart surgery a decrease of hospital mortality has been observed in many surgical institutions. The ratio between the increase of risk and the decrease of mortality could be defined as the 'risk paradox' for coronary surgery. Meanwhile an increase of the incidence of postoperative complications is leading to a longer stay in intensive care that involves a remarkable cost increase per single hospitalisation and a disproportionally long-term use of reanimation beds in those patients who survive the operation but have comorbidities complicating the postoperative course. This progressive change of the epidemiology of patients undergoing heart surgery is coupled with a progressive increase of costs. In the present review a comparison of stratification models developed to predict hospital mortality with those developed to predict prolonged stay in intensive care is discussed. Such predictions are not obviously aimed at deciding whether to operate a patient or not, but can be looked in managing high risk patients, e.g. by a daily monitoring and revision of their prognosis and relevant therapeutic choices, as well as in discussing with their relatives about whether to continue or not implacable treatments. After identifying the models, it is desirable that they are spread into professional Societies in order to sensitise field operators' awareness on the issue of proper intervention indications and on the opportunity of identifying those patients for whom an intervention is not to be advised and to whom propose medical or intervention treatments.

Predicting death from ruptured abdominal aortic aneurysms

Background: We have previously reported preoperative and immediate postoperative formulae to estimate mortality in patients with ruptured abdominal aortic aneurysms (rAAA). In this study, we prospectively compared these formulae in patients with rAAA with their actual outcomes. Methods: Information was collected on 134 patients from two centers over a 3-year period. Preoperative mortality risk was estimated using coefficients for age, level of consciousness, and cardiac arrest. Mortality risk in the immediate postoperative state was based on the presence of coagulopathy, ischemic colitis, prolonged requirement for inotropes, time from arrival at hospital to surgery, patient age, perioperative myocardial infarction, renal failure, and pre-operative hemoglobin level. Results: The average age was 73 years (range 30 to 92 y) and 20 of 134 (15%) patients were women. Sixty-three patients (47%) survived. For patients with a calculated preoperative mortality risk of >90%, the sensitivity, specificity, and positive and negative predictive values were 25%, 98%, 95%, and 54%, respectively. For a mortality risk >80%, these values were 37%, 94%, 87%, and 57%, respectively. For patients with an estimated immediate postoperative mortality risk ≥90%, the sensitivity, specificity, and positive and negative predictive values were 17%, 87%, 60%, and 49%, respectively. For a predicted mortality ≥80%, these values were 22%, 84%, 60%, and 50%, respectively. Conclusions: Our formula for predicting mortality for preoperative rAAA patients may be useful for patients with an estimated mortality risk ≥90%, based on the high positive predictive value. The formula for immediate postoperative rAAA patients was not useful in predicting death.

Perioperative Predictors of ICU and Hospital Costs in Coronary Artery Bypass Graft Surgery

Economic forces have precipitated intense interest in cost-saving practices for patients undergoing coronary artery bypass grafting (CABG). While several preoperative variables have been implicated in higher costs, few studies have included perioperative factors. This study evaluated the predictive power of a preoperative mortality risk measurement (Parsonnet score) and of early extubation (< or = 6 h from ICU admission) in determining ICU and hospital costs. Multivariate correlational design. University hospital in a large metropolitan area. All patients (n = 116) undergoing isolated CABG during a 6-month period were studied after the introduction of a clinical pathway. Clinical data were collected. Costs data were obtained retrospectively from the institutional data system and were derived from individual patient charges by application of department-specific cost-to-charge ratios. In multivariate logistic regression, Parsonnet score (per point odds ratio [OR], 1.09; confidence interval [CI], 1.03 to 1.17), in-hospital coronary angiography (OR, 3.51; CI, 1.23 to 10.01), delayed extubation (OR, 4.59; CI, 1.29 to 16.29), and presence of arrhythmia (OR, 3.50; CI, 1.15 to 10.64) were independent predictors of ICU costs. Only Parsonnet score (OR, 1.09; CI, 1.03 to 1.15) and cardiopulmonary bypass time (OR, 1.01; CI, 1.00 to 1.02) were independent predictors of hospital costs. The Parsonnet score is a useful indicator of both ICU and hospital costs. Early extubation is associated with decreased ICU costs, but is not independently predictive of hospital costs.

Intraoperative physiologic variables and outcome in cardiac surgery: part I. In-hospital mortality

Background. Risk stratification schemes have been developed to predict outcome of coronary artery bypass grafting (CABG) procedures, which are predominately based upon unalterable preoperative patient characteristics. The purpose of this study was to determine if minimum intraoperative hematocrit, maximum glucose concentration, mean arterial pressure on cardiopulmonary bypass, or duration of bypass influence risk-adjusted in-hospital mortality after CABG.Methods. Outcome data from 2,862 CABG patients were merged with intraoperative physiologic data. A preoperative mortality risk index was calculated for each patient. Variables found significant (p < 0.05) by univariate logistic regression were tested in a multiple variable model to determine risk-adjusted association with mortality.Results. Overall mortality rate was 1.85%. The preoperative risk index was significantly associated with mortality (p = 0.0001). No significant association was present between mortality and intraoperative variables. Preexisting hypertension was an independent predictor of mortality after controlling for risk index and bypass duration.Conclusions. Preexisting hypertension proved to be an independent predictor of mortality in our patient population. This study found no evidence to support the hypothesis that mean arterial pressure less than 50 mm Hg, lower hematocrit, or elevated glucose while on bypass increases in-hospital mortality.