Stewart J. Lustik

The Surgical Mortality Probability Model: derivation and validation of a simple risk prediction rule for noncardiac surgery.

Objective:To develop a 30-day mortality risk index for noncardiac surgery that can be used to communicate risk information to patients and guide clinical management at the “point-of-care,” and that can be used by surgeons and hospitals to internally audit their quality of care. Background:Clinicians rely on the Revised Cardiac Risk Index to quantify the risk of cardiac complications in patients undergoing noncardiac surgery. Because mortality from noncardiac causes accounts for many perioperative deaths, there is also a need for a simple bedside risk index to predict 30-day all-cause mortality after noncardiac surgery. Methods:Retrospective cohort study of 298,772 patients undergoing noncardiac surgery during 2005 to 2007 using the American College of Surgeons National Surgical Quality Improvement Program database. Results:The 9-point S-MPM (Surgical Mortality Probability Model) 30-day mortality risk index was derived empirically and includes three risk factors: ASA (American Society of Anesthesiologists) physical status, emergency status, and surgery risk class. Patients with ASA physical status I, II, III, IV or V were assigned either 0, 2, 4, 5, or 6 points, respectively; intermediate- or high-risk procedures were assigned 1 or 2 points, respectively; and emergency procedures were assigned 1 point. Patients with risk scores less than 5 had a predicted risk of mortality less than 0.50%, whereas patients with a risk score of 5 to 6 had a risk of mortality between 1.5% and 4.0%. Patients with a risk score greater than 6 had risk of mortality more than 10%. S-MPM exhibited excellent discrimination (C statistic, 0.897) and acceptable calibration (Hosmer-Lemeshow statistic 13.0, P = 0.023) in the validation data set. Conclusions:Thirty-day mortality after noncardiac surgery can be accurately predicted using a simple and accurate risk score based on information readily available at the bedside. This risk index may play a useful role in facilitating shared decision making, developing and implementing risk-reduction strategies, and guiding quality improvement efforts.

The impact of anesthesiologists on coronary artery bypass graft surgery outcomes.

BACKGROUND One of every 150 hospitalized patients experiences a lethal adverse event; nearly half of these events involves surgical patients. Although variations in surgeon performance and quality have been reported in the literature, less is known about the influence of anesthesiologists on outcomes after major surgery. Our goal of this study was to determine whether there is significant variation in outcomes between anesthesiologists after controlling for patient case mix and hospital quality. METHODS Using clinical data from the New York State Cardiac Surgery Reporting System, we conducted a retrospective observational study of 7920 patients undergoing isolated coronary artery bypass graft surgery. Multivariable logistic regression modeling was used to examine the variation in death or major complications (Q-wave myocardial infarction, renal failure, stroke) across anesthesiologists, controlling for patient demographics, severity of disease, comorbidities, and hospital quality. RESULTS Anesthesiologist performance was quantified using fixed-effects modeling. The variability across anesthesiologists was highly significant (P < 0.001). Patients managed by low-performance anesthesiologists (corresponding to the 25th percentile of the distribution of anesthesiologist risk-adjusted outcomes) experienced nearly twice the rate of death or serious complications (adjusted rate 3.33%; 95% confidence interval [CI], 3.09%-3.58%) as patients managed by high-performance anesthesiologists (corresponding to the 75th percentile) (adjusted rate 1.82%; 95% CI, 1.58%-2.10%). This performance gap was observed across all patient risk groups. CONCLUSIONS The rate of death or major complications among patients undergoing coronary artery bypass graft surgery varies markedly across anesthesiologists. These findings suggest that there may be opportunities to improve perioperative management to improve outcomes among high-risk surgical patients.

Anesthesia care for adult live donor hepatectomy: Our experiences with 100 cases

A total of 100 patients who underwent elective lobar donor hepatectomy from 2000 to 2002 at the University of Rochester Medical Center were reviewed. Assessed clinical data were estimated blood loss, intraoperative central venous pressure (CVP), blood product and fluid administration, perioperative arterial blood gas tension and acid‐base state, metabolic status, perioperative serum levels of aspartate aminotransferase, alanine aminotransferase, prothrombin time, albumin, and lactate, procedure duration, and perioperative complications. All patients survived surgery, and the average duration of surgery (from skin incision to skin closure) was 615 ± 99.6 minutes. Mean blood loss was 549 ± 391 mL (range, 80‐2,500 mL), and only 4 patients required homologous blood transfusion. The intraoperative blood loss did not correlate with CVP values. A total of 72 patients received isotonic sodium bicarbonate solution, and their metabolic variables were superior to those of normal saline group patients (arterial pH, 7.35 ± 0.03 vs. 7.29 ± 0.07; base excess, −4.3 ± 2.4 vs. 7.3 ± 3.4; and serum bicarbonate level, 20.6 ± 2.2 vs. 18.6 ± 2.9). However, the better control of metabolic acidosis was not associated with serum lactate levels or other outcome measures. Maintaining the CVP < 5 mmHg was not associated with blood loss. Clinically significant anesthetic complications were severe metabolic acidosis, pneumothorax and respiratory insufficiency immediately following extubation in the operating room. In conclusion, placement of a thoracic epidural catheter delivering a local anesthetic in addition to intravenous (IV) patient‐controlled analgesia with opiates provided safe and effective pain control in most patients. Further prospective studies should shed a light on the optimal care of patients undergoing liver donor hepatic resection. Liver Transpl 13:537–542, 2007.

Variation of blood transfusion in patients undergoing major noncardiac surgery.

Objective: To examine the hospital variability in use of red blood cells (RBCs), fresh-frozen plasma (FFP), and platelet transfusions in patients undergoing major noncardiac surgery. Background: Blood transfusion is commonly used in surgical procedures in the United States. Little is known about the hospital variability in perioperative transfusion rates for noncardiac surgery. Methods: We used the University HealthSystem Consortium database (2006–2010) to examine hospital variability in use of allogeneic RBC, FFP, and platelet transfusions in patients undergoing major noncardiac surgery. We used regression-based techniques to quantify the variability in hospital transfusion practices and to study the association between hospital characteristics and the likelihood of transfusion. Results: After adjusting for patient risk factors, hospital transfusion rates varied widely for patients undergoing total hip replacement (THR), colectomy, and pancreaticoduodenectomy. Compared with patients undergoing THR in average-transfusion hospitals, patients treated in high-transfusion hospitals have a greater than twofold higher odds of being transfused with RBCs [adjusted odds ratio (AOR) = 2.41; 95% confidence interval (CI), 1.89–3.09], FFP (AOR = 2.81; 95% CI, 2.02–3.91), and platelets (AOR = 2.52; 95% CI, 1.95–3.25), whereas patients in low-transfusion hospitals have an approximately 50% lower odds of receiving RBCs (AOR = 0.45; 95% CI, 0.35–0.57), FFP (AOR = 0.37; 95% CI, 0.27–0.51), and platelets (AOR = 0.42; 95% CI, 0.29–0.62). Similar results were obtained for colectomy and pancreaticoduodenectomy. Conclusions: There was dramatic hospital variability in perioperative transfusion rates among patients undergoing major noncardiac surgery at academic medical centers. In light of the potential complications of transfusion therapy, reducing this variability in hospital transfusion practices may result in improved surgical outcomes.

Effects of Anticholinergics on Postoperative Vomiting, Recovery, and Hospital Stay in Children Undergoing Tonsillectomy with or without Adenoidectomy

BACKGROUND Nausea and vomiting are the most frequent problems after minor ambulatory surgical procedures. The agents used to induce and maintain anesthesia may modify the incidence of emesis. When neuromuscular blockade is antagonized with anticholinesterases, atropine or glycopyrrolate is used commonly to prevent bradycardia and excessive oral secretions. This study was designed to evaluate the effect of atropine and glycopyrrolate on postoperative vomiting in children. METHODS Ninety-three patients undergoing tonsillectomy with or without adenoidectomy were studied. After inhalation induction of anesthesia with nitrous oxide, oxygen, and halothane, anesthesia was maintained with a nitrous oxide-oxygen mixture, halothane, morphine, and atracurium. Patients were randomized to receive, in a double-blinded manner, either 15 microg/kg atropine or 10 microg/kg glycopyrrolate with 60 microg/kg neostigmine to reverse neuromuscular blockade. Patient recovery, the incidence of postoperative emesis, antiemetic therapy, and the duration of postoperative hospital stay were assessed. RESULTS There were no significant differences in age, gender, weight, or discharge time from the postanesthesia care unit or the hospital between the groups. Twenty-four hours after operation, the incidence of vomiting in the atropine group (56%) was significantly less than in the glycopyrrolate group (81%; P<0.05). There was no significant difference between the atropine and glycopyrrolate groups in the number of patients who required antiemetics or additional analgesics. CONCLUSIONS In children undergoing tonsillectomy with or without adenoidectomy, reversal of neuromuscular blockade with atropine and neostigmine is associated with a lesser incidence of postoperative emesis compared with glycopyrrolate and neostigmine.

Lack of Lung Hemorrhage in Humans After Intraoperative Transesophageal Echocardiography with Ultrasound Exposure Conditions Similar to Those Causing Lung Hemorrhage in Laboratory Animals

This study investigated the phenomenon of ultrasonically induced lung hemorrhage in humans. Multiple experimental laboratories have shown that diagnostic ultrasound exposure can cause hemorrhage in the lungs of laboratory animals. The left lung of 50 patients (6 women, 44 men, mean age 61 years) was observed directly by the surgeon after routine intraoperative transesophageal echocardiography was performed. From manufacturer specifications the maximum derated intensity in the sound field of the system used was 186 W/cm2, the maximum derated rarefactional acoustic pressure was 2.4 MPa, and the maximum mechanical index was 1.3. The lowest frequency used was 3.5 MHz. This exposure exceeds the threshold found for surface lung hemorrhage seen on gross observation of laboratory animals. No hemorrhage was noted on any lung surface by the surgeon on gross observation. We conclude that clinical transesophageal echocardiography, even at field levels a little greater than the reported thresholds for lung hemorrhage in laboratory animals, did not cause surface lung hemorrhage apparent on gross observation. These negative results support the conclusion that the human lung is not markedly more sensitive to ultrasound exposure than that of other mammals.

Preoperative thrombocytopenia and postoperative outcomes after noncardiac surgery.

Background:Most studies examining the prognostic value of preoperative coagulation testing are too small to examine the predictive value of routine preoperative coagulation testing in patients having noncardiac surgery. Methods:Using data from the American College of Surgeons National Surgical Quality Improvement database, the authors performed a retrospective observational study on 316,644 patients having noncardiac surgery who did not have clinical indications for preoperative coagulation testing. The authors used multivariable logistic regression analysis to explore the association between platelet count abnormalities and red cell transfusion, mortality, and major complications. Results:Thrombocytopenia or thrombocytosis occurred in 1 in 14 patients without clinical indications for preoperative platelet testing. Patients with mild thrombocytopenia (101,000–150,000 µl−1), moderate-to-severe thrombocytopenia (<100,000 µl−1), and thrombocytosis (≥450,000 µl−1) were significantly more likely to be transfused (7.3%, 11.8%, 8.9%, 3.1%) and had significantly higher 30-day mortality rates (1.5%, 2.6%, 0.9%, 0.5%) compared with patients with a normal platelet count. In the multivariable analyses, mild thrombocytopenia (adjusted odds ratio [AOR], 1.28; 95% CI, 1.18–1.39) and moderate-to-severe thrombocytopenia (AOR, 1.76; 95% CI, 1.49–2.08), and thrombocytosis (AOR, 1.44; 95% CI, 1.30–1.60) were associated with increased risk of blood transfusion. Mild thrombocytopenia (AOR, 1.31; 95% CI, 1.11–1.56) and moderate-to-severe thrombocytopenia (AOR, 1.93; 95% CI, 1.43–2.61) were also associated with increased risk of 30-day mortality, whereas thrombocytosis was not (AOR, 0.94; 95% CI, 0.72–1.22). Conclusion:Platelet count abnormalities found in the course of routine preoperative screening are associated with a higher risk of blood transfusion and death.

Outcomes are Worse in US Patients Undergoing Surgery on Weekends Compared With Weekdays.

Background:Increasing surgical access to previously underserved populations in the United States may require a major expansion of the use of operating rooms on weekends to take advantage of unused capacity. Although the so-called weekend effect for surgery has been described in other countries, it is unknown whether US patients undergoing moderate-to-high risk surgery on weekends are more likely to experience worse outcomes than patients undergoing surgery on weekdays. Objective:The aim of this study was to determine whether patients undergoing surgery on weekends are more likely to die or experience a major complication compared with patients undergoing surgery on a weekday. Research Design:Using all-payer data, we conducted a retrospective cohort study of 305,853 patients undergoing isolated coronary artery bypass graft surgery, colorectal surgery, open repair of abdominal aortic aneurysm, endovascular repair of abdominal aortic aneurysm, and lower extremity revascularization. We compared in-hospital mortality and major complications for weekday versus weekend surgery using multivariable logistic regression analysis. Results:After controlling for patient risk and surgery type, weekend elective surgery [adjusted odds ratio (AOR)=3.18; 95% confidence interval (CI), 2.26–4.49; P<0.001] and weekend urgent surgery (AOR=2.11; 95% CI, 1.68–2.66; P<0.001) were associated with a higher risk of death compared with weekday surgery. Weekend elective (AOR=1.58; 95% CI, 1.29–1.93; P<0.001) and weekend urgent surgery (AOR=1.61; 95% CI, 1.42–1.82; P<0.001) were also associated with a higher risk of major complications compared with weekday surgery. Conclusions:Patients undergoing nonemergent major cardiac and noncardiac surgery on the weekends have a clinically significantly increased risk of death and major complications compared with patients undergoing surgery on weekdays. These findings should prompt decision makers to seek to better understand factors, such physician and nurse staffing, which may contribute to the weekend effect.

Treatment of a paradoxical reaction to midazolam with haloperidol.

B enzodiazepines are administered to patients prior to procedures or surgery to provide anxiolysis, amnesia, and sedation. Benzodiazepines facilitate binding of y-aminobutyric acid (GABA) to GABA, receptors in the central nervous system (CNS) (1). This enhances GABA-mediated neuronal inhibition in the cortex and the limbic system, which regulates emotion. Although most patients become calm after receiving benzodiazepines, it has been well documented that benzodiazepines can rarely cause hostility, aggressiveness, confusion, and agitation (2-4). The etiology of these paradoxical reactions is unknown, although some authors have postulated that benzodiazepines alter the levels of multiple CNS neurotransmitters (e.g., catecholamines, serotonin, and acetylcholine), which causes disinhibitory behavior in susceptible subjects (3). The disinhibiting effects of benzodiazepines may become exaggerated in patients in stressful or aggravating situations (4-6). It has also been proposed that paradoxical reactions are more common in patients who are at the extremes of age, who have baseline hostile-depressive or aggressive personalities, or who are receiving large doses of intravenous (IV) short-acting benzodiazepines (3,4,7-10). Recommended treatments for paradoxical reactions have included increasing benzodiazepine doses, physostigmine (ll), or, more recently, the benzodiazepine antagonist flumazenil (7,10,12). In our patient who had an intraaortic balloon pump (IABP) in place and was awaiting coronary artery bypass graft (CABG) surgery, we successfully treated a paradoxical reaction to midazolam with small doses of IV haloperidol.

Ephedrine-induced coronary artery vasospasm in a patient with prior cocaine use

A 42-yr-old male with peripheral vascular disease presented for a right femoral-popliteal bypass procedure. Despite lower extremity claudication, the patient worked lo-13 h daily at an automotive plant, assembling heavy machinery and pulling carts weighing up to 120 pounds. He denied chest pain, palpitations, or syncope. Although his arterial blood pressure during preoperative evaluation 5 days prior to surgery was 173155 mm Hg, he had no history of hypertension and multiple subsequent blood pressures were normotensive with a normal pulse pressure. He had a history of untreated glucose intolerance; a nonfasting preoperative blood glucose level was 132 mg/dL. He had smoked threefourths of a pack of cigarettes per day for 15 yr. He used cocaine almost daily many years ago, but claimed only monthly use over the last 10 yr and that he last used cocaine at a party 4 days prior to surgery. He was taking no medications. Electrocardiogram (ECG) revealed sinus bradycardia at 55 bpm. The patient desired spinal anesthesia. In the preanesthesia room, he received 4 mg of midazolam intravenously (IV). After infusing 700 mL IV of lactated Ringer’s solution, 15 mg of bupivacaine and 0.2 mg of preservative-free morphine were injected intrathecally at the L3-4 interspace. The patient was placed in the right lateral decubitus position for 5 min, and then placed supine with a sensory block to the T-6 dermatome. Arterial blood pressure decreased from 115 / 60 mm Hg to 88/40 mm Hg with an increase in heart rate from 65 to 70 bpm, and the patient complained of nausea. Ephedrine 10 mg was given IV. Approximately 30 s later, the patient