Preoperative stress testing in high-risk vascular surgery and its association with gender.

BACKGROUND: Despite significant improvement in anesthetic and surgical techniques, the incidence of perioperative myocardial infarction (PMI) and all-cause mortality from any cardiac event during high-risk vascular surgery (abdominal aortic or infrainguinal revascularization procedures) remains high. In addition, there are significant health care costs associated with the management of PMI. OBJECTIVES: The aim of this analysis was to investigate the utility of routine preoperative myocardial stress testing prior to high-risk vascular surgery and the interventions performed based on the results of the testing. The outcome after surgery, based on sex of the patients, was also examined. METHODS: A retrospective analysis was performed on consecutive adult patients who had a positive dipyridamole-thallium stress test prior to high-risk vascular surgery in a university hospital (tertiary care center) between July 2001 and August 2004. The patients' preoperative demographic characteristics, perioperative record, and postoperative course in the hospital were analyzed. Combined major adverse outcome was defined as any incidence of MI, congestive heart failure, arrhythmias, renal failure, or death. RESULTS: Of a total of 503 patients, 160 had a positive stress test prior to high-risk vascular surgery (111 men, 49 women; mean [SD] age, 68 [11] and 70 [12] years, respectively). Men with a positive stress test who had either coronary intervention or perioperative ß-blockade prior to surgery had a significant decrease in the incidence of combined major adverse outcomes (P = 0.02). Conversely, women did not have a significant improvement in outcome with either of the preoperative strategies. Using logistic regression, only age and conservative management in men were found to be predictors of adverse outcomes. CONCLUSIONS: In this small retrospective study, men with positive stress tests had fewer adverse events with either preoperative coronary revascularization or perioperative administration of ß-adrenergic blocking drugs, compared with men who received no intervention. There were no significant differences in adverse outcomes between women with positive stress tests who received either treatment compared with those who did not receive any treatment.

Can efficient supply management in the operating room save millions?

PURPOSE OF REVIEW: Supply expenses occupy an ever-increasing portion of the expense budget in today's increasingly technologically complex operating rooms. Yet, little has been studied and published in the anesthesia literature. This review attempts to bring the topic of supply management to anesthesiologists, who play a significant role in operating room management. RECENT FINDINGS: Little investigative work has been performed on supply management. Anecdotal reports suggest the benefits of a perpetual inventory system over a periodic inventory system. A perpetual inventory system uses utilization data to update inventory on hand continually and this information is linked to purchasing and restocking, whereas a periodic inventory system counts inventory at some regular intervals (such as annually) and uses average utilization to set par levels. SUMMARY: On the basis of application of operational management concepts, ways of taking advantage of a perpetual inventory system to achieve savings in supply expenses are outlined. These include linking the operating room scheduling and supply order system, distributor-driven just-in-time delivery of case carts, continual updating of preference lists based on utilization patterns, increasing inventory turnovers, standardizing surgical practices, and vendor consignment of high unit-cost items such as implants. In addition, Lean principles of visual management and elimination of eight wastes may be applicable to supply management.

Sex-related differences in outcome after high-risk vascular surgery after the administration of beta-adrenergic-blocking drugs.

BACKGROUND: Beta-adrenergic-blocking medications may have a cardioprotective effect after high-risk vascular surgery. This effect has been shown primarily in men and has not been independently shown in women. METHODS: Retrospective data were collected from vascular surgery (primarily infrainguinal) patients. Adverse outcome was defined as myocardial infarction, new-onset congestive heart failure (CHF), significant arrhythmia, renal failure, or death. The incidence of adverse outcomes was compared independently for both men and women based on the administration of perioperative beta-blockade. Analysis was performed for the whole population and for the subset of patients who were not on preoperative beta-blockers (beta-blocker naïve). Risk-stratified analysis was used to determine which group received any effect from beta-blockade. Logistic regression was performed to determine the independent effect of perioperative beta-blockade in both sexes. RESULTS: There were 594 men and 366 women. The incidence of adverse outcomes was lower when beta-blockers were administered in men (12.6% v 18.9%, p = 0.04) but not in women (17.8% v 13.7%, p = 0.37). Among beta-blocker-naïve subjects, men had significant reductions in myocardial infarction and renal failure, whereas women did not have a reduction in the incidence of any outcome. After risk-stratification, the high-risk women who received beta-blockade had a statistically worse outcome (36.8% v 5.9%, p = 0.02) because of an increased incidence of CHF. By logistic regression, beta-blockade improved outcomes in men but not women. CONCLUSION: In this retrospective analysis, women did not benefit from perioperative beta-blockade. Women at high risk appeared to have a worse outcome because of a higher incidence of CHF.

Effects of ulinastatin on pulmonary artery pressure during abdominal aortic aneurysmectomy.

STUDY OBJECTIVE: Abdominal aortic aneurysmectomy (AAAectomy) results in a general ischemia-reperfusion syndrome accompanied by an acute rise in pulmonary artery pressure (PAP). We examined whether ulinastatin, a urinary trypsin inhibitor, prevents ischemia-reperfusion injury and increase in PAP after aortic unclamping (XU) during AAAectomy. DESIGN: Prospective study. SETTING: Public, university-affiliated hospital. PATIENTS: Sixteen patients (11 males and 5 females) scheduled for AAAectomy. INTERVENTIONS AND MEASUREMENTS: The patients received 300000 IU of ulinastatin intravenously before XU (n = 8) or no additional treatment (n = 8) (control). Heart rate, central venous pressure, PAP, pulmonary arterial wedge pressure, arterial pressure, mixed venous oxygen saturation (Sv(O2)), and cardiac output were monitored. Arterial and mixed venous blood samples were analyzed for pH, Pa(CO2), Pa(O2), hemoglobin, and oxygen saturation, and the physiological shunt function (Qs/Qt) were calculated. Plasma concentrations of malondialdehyde, myeloperoxidase, granulocyte elastase, alpha1-antitrypsine, and thromboxane B2 and the stable hydrolysis products of thromboxane A2 were measured. Measurements were conducted before aortic crossclamping (XC) (baseline) and at 10, 30, and 60 minutes after XU. MAIN RESULTS: A significant increase in PAP was observed 10 minutes after XU in the control group but not in the ulinastatin group. At 60 minutes after XU, Qs/Qt values had increased in the control group but had decreased in the ulinastatin group. There were no significant changes in malondialdehyde, thromboxane B2, granulocyte elastase, and alpha1-antitrypsine levels after XU in either group. A significant decrease in the plasma level of myeloperoxidase after XU was found in both groups. CONCLUSIONS: The present study demonstrated that ulinastatin prevents increase in PAP and shunting after XU during AAAectomy.

Inadvertent placement of a flow-directed pulmonary artery catheter in the coronary sinus, detected by transesophageal echocardiography.

We report a case in which flow-directed placement of the pulmonary artery catheter led to its inadvertent placement in the coronary sinus, in the absence of congenital anomalies. Incorrect placement was diagnosed by use of the transesophageal echocardiography. If unrecognized, the catheter might have provided misleading information and led to mismanagement of the patient.

Patients with positive preoperative stress tests undergoing vascular surgery.

OBJECTIVE: To examine the perioperative cardiac morbidity and mortality in patients undergoing major vascular surgery with beta-blockade after a positive stress test or cardiac catheterization. DESIGN: Retrospective review of a quality assurance database. SETTING: A university teaching hospital. PARTICIPANTS: A consecutive series of 31 patients undergoing peripheral vascular or aortic surgery after a positive stress test or catheterization between November 2001 and September 2003. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: All 31 patients had a preoperative positive stress test and/or cardiac catheterization, with 12 having multiple areas at risk for myocardial ischemia. None had an intervening coronary revascularization. Twenty-seven had at least one of the intermediate clinical predictors as defined by the American College of Cardiology and 7 had a left ventricular ejection fraction < 40%. Twenty-three patients had been on a beta-blocker and continued on it, while the remainder started on it de novo perioperatively. None of the patients suffered from myocardial infarction, congestive heart failure, or cardiac death perioperatively. CONCLUSIONS: This case series reports on the authors' experience with patients undergoing high-risk vascular surgery after a positive stress test or catheterization, but without an intervening coronary intervention. All patients received perioperative beta-blockade and had a very low adverse cardiac event rate. With reduction of adverse events by beta-blockade, the likelihood of a positive event may be reduced and the utility of the test in risk stratification may be questioned.

Perioperative and long-term morbidity and mortality after above-knee and below-knee amputations in diabetics and nondiabetics.

We performed a retrospective review of a vascular surgery quality assurance database to evaluate the perioperative and long-term morbidity and mortality of above-knee amputations (AKA, n = 234) and below-knee amputations (BKA, n = 720) and to examine the effect of diabetes mellitus (DM) (181 of AKA and 606 of BKA patients). All patients in the database who had AKA or BKA from 1990 to May 2001 were included in the study. Perioperative 30-day cardiac morbidity and mortality and 3-yr and 10-yr mortality after AKA or BKA were assessed. The effect of DM on 30-day cardiac outcome was assessed by multivariate logistic regression and the effect on long-term survival was assessed by Cox regression analysis. The perioperative cardiac event rate (cardiac death or nonfatal myocardial infarction) was at least 6.8% after AKA and at most 3.6% after BKA. Median survival was significantly less after AKA (20 mo) than BKA (52 mo) (P < 0.001). DM was not a significant predictor of perioperative 30-day mortality (odds ratio, 0.76 [0.39-1.49]; P = 0.43) or 3-yr survival (Hazard ratio, 1.03 [0.86-1.24]; P = 0.72) but predicted 10-yr mortality (Hazard ratio, 1.34 [1.04-1.73]; P = 0.026). Significant predictors of the 30-day perioperative mortality were the site of amputation (odds ratio, 4.35 [2.56-7.14]; P < 0.001) and history of renal insufficiency (odds ratio, 2.15 [1.13-4.08]; P = 0.019). AKA should be triaged as a high-risk surgery while BKA is an intermediate-risk surgery. Long-term survival after AKA or BKA is poor, regardless of the presence of DM.