Avoiding Retained Surgical Items at an Academic Medical Center: Sustainability of a Surgical Quality Improvement Project.

Unintentionally retained surgical items (RSIs) are a serious complication representing a surgical "Never" event. The authors previously reported the process and significant improvement over a 3-year multiphased quality improvement RSI reduction effort that included sponge-counting technology. Herein, they report the sustainability of that effort over the decade following the formal quality improvement project conclusion. This retrospective analysis includes descriptive and qualitative data collected during RSI event root cause analysis. Between January 2009 and December 2019, 640 889 operations were performed with 24 RSIs reported. The resulting RSI rate of 1 per 26 704 operations represent a 486% performance improvement compared to the preintervention rate of 1 per 5500 operations. The interval, in days, between RSI events increased to 160 from 26 during the preintervention phase. Cotton sponges were the most retained RSI despite the use of sponge-counting technology. A significant and sustained reduction in RSI is possible after designing a sustainable comprehensive multidisciplinary effort.

The utility of chest computed tomography (CT) and RT-PCR screening of asymptomatic patients for SARS-CoV-2 prior to semiurgent or urgent hospital procedures.

OBJECTIVE: Presently, evidence guiding clinicians on the optimal approach to safely screen patients for coronavirus disease 2019 (COVID-19) to a nonemergent hospital procedure is scarce. In this report, we describe our experience in screening for SARS-CoV-2 prior to semiurgent and urgent hospital procedures. DESIGN: Retrospective case series. SETTING: A single tertiary-care medical center. PARTICIPANTS: Our study cohort included patients ≥18 years of age who had semiurgent or urgent hospital procedures or surgeries. METHODS: Overall, 625 patients were screened for SARS-CoV-2 using a combination of phone questionnaire (7 days prior to the anticipated procedure), RT-PCR and chest computed tomography (CT) between March 1, 2020, and April 30, 2020. RESULTS: Of the 625 patients, 520 scans (83.2%) were interpreted as normal; 1 (0.16%) had typical features of COVID-19; 18 scans (2.88%) had indeterminate features of COVID-19; and 86 (13.76%) had atypical features of COVID-19. In total, 640 RT-PCRs were performed, with 1 positive result (0.15%) in a patient with a CT scan that yielded an atypical finding. Of the 18 patients with chest CTs categorized as indeterminate, 5 underwent repeat negative RT-PCR nasopharyngeal swab 1 week after their initial swab. Also, 1 patient with a chest CT categorized as typical had a follow-up repeat negative RT-PCR, indicating that the chest CT was likely a false positive. After surgery, none of the patients developed signs or symptoms suspicious of COVID-19 that would indicate the need for a repeated RT-PCR or CT scan. CONCLUSION: In our experience, chest CT scanning did not prove provide valuable information in detecting asymptomatic cases of SARS-CoV-2 (COVID-19) in our low-prevalence population.

Overall Cost Comparison of Gastrointestinal Endoscopic Procedures With Endoscopist- or Anesthesia-Supported Sedation by Activity-Based Costing Techniques.

OBJECTIVE: Endoscopic/colonoscopic procedures are either done with gastroenterologist-administered conscious sedation or with anesthesia-administered sedation with propofol. There are potential benefits to anesthesia-administered sedation, but the concern has been the associated increased cost. METHODS: To perform this study, we used the time-derived activity-based costing (TDABC) technique to accurately assess the true cost of gastrointestinal procedures done with gastroenterologist-administered conscious sedation vs anesthesia-administered sedation in 2 areas of our practice that use predominantly conscious sedation or anesthesia-administered sedation. This type of study has never been reported using such an integrated approach. This study was performed on 2 different days in June 2015. RESULTS: The true cost associated with anesthesia-administered sedation in our practice was associated with only 9% to 24% greater cost when the TDABC technique was applied. CONCLUSION: Gastrointestinal procedures with anesthesia-administered sedation are not as costly when all factors are considered. Using novel approaches to cost measurement, such as the TDABC, allows a total cost measurement approach across an episode of care that existing cost measurements in health care are incapable of.

Anesthesia Care Transitions and Risk of Postoperative Complications.

BACKGROUND: A patient undergoing surgery may receive anesthesia care from several anesthesia providers. The safety of anesthesia care transitions has not been evaluated. Using unconditional and conditional multivariable logistic regression models, we tested whether the number of attending anesthesiologists involved in an operation was associated with postoperative complications. METHODS: In a cohort of patients undergoing elective colorectal surgical in an academic tertiary care center with a stable anesthesia care team model participating in the American College of Surgeons National Surgical Quality Improvement Program, using unconditional and conditional multivariable logistic regression models, we tested adjusted associations between numbers of attending anesthesiologists and occurrence of death or a major complication (acute renal failure, bleeding that required a transfusion of 4 units or more of red blood cells within 72 hours after surgery, cardiac arrest requiring cardiopulmonary resuscitation, coma of 24 hours or longer, myocardial infarction, unplanned intubation, ventilator use for 48 hours or more, pneumonia, stroke, wound disruption, deep or organ-space surgical-site infection, superficial surgical-site infection, sepsis, septic shock, systemic inflammatory response syndrome). RESULTS: We identified 927 patients who underwent elective colectomy of comparable surgical intensity. In all, 71 (7.7%) patients had major nonfatal complications or death. One anesthesiologist provided care for 530 (57%) patients, 2 anesthesiologists for 287 (31%), and 3 or more for 110 (12%). The number of attending anesthesiologists was associated with increased odds of postoperative complication (unadjusted odds ratio [OR] = 1.52, 95% confidence interval [CI] 1.18-1.96, P = 0.0013; adjusted OR = 1.44, 95% CI 1.09-1.91, P = 0.0106). In sensitivity analyses, occurrence of a complication was significantly associated with the number of in-room providers, defined as anesthesia residents and nurse anesthetists (adjusted OR = 1.39, 95% CI 1.01-1.92, P = 0.0446) and for all anesthesia providers (adjusted OR = 1.58, 95%CI 1.20-2.08, P = 0.0012). Findings persisted across multiple, alternative adjustments, sensitivity analyses, and conditional logistic regression with matching on operative duration. CONCLUSIONS: In our study, care by additional attending anesthesiologists and in-room providers was independently associated with an increased odds of postoperative complications. These findings challenge the assumption that anesthesia transitions are care neutral and not contributory to surgical outcomes.

Perioperative Glucose Management: Point-of-Care Testing and Pseudohypoglycemia.

Perioperative hypoglycemia has been associated with adverse outcomes. Consequently, perioperative monitoring of blood glucose using convenient point-of-care (POC) monitors is frequently used. Although venous or arterial glucose POC testing has been cleared for use in critically ill hospitalized patients, the results of capillary glucose POC testing should be interpreted with caution because capillary POC samples are usually less reliable than those obtained from arterial or venous sites. We describe a case of pseudohypoglycemia using such testing. This case highlights the importance of individualizing perioperative glucose management to venous or arterial rather than capillary sampling in certain clinical situations.

Effects of changes in intraoperative management on recovery from anesthesia: a review of practice improvement initiative.

BACKGROUND: Our anesthetic practice was hindered by inadequate postanesthesia care unit space resulting in operating room inefficiencies. In response, an anesthetic protocol designed to reduce the duration of postanesthesia stay by decreasing residual anesthetic sedation and postoperative nausea and vomiting (PONV) was introduced. Here the impact of this practice change is analyzed. METHODS: The protocol encouraged desflurane use instead of isoflurane, triple antiemetic prophylaxis, and discouraged midazolam. Records of patients undergoing general anesthesia from calendar-matched epochs were reviewed. Epoch I included a 6-month period prior to implementation of the practice change (October 1, 2009, to March 31, 2010) and Epoch II included 6 months following the practice change (October 1, 2010, to March 31, 2011). RESULTS: General anesthesia was administered to 2,936 and 3,137 patients during Epochs I and II, respectively. Midazolam decreased from 57.4% to 24.0%, isoflurane from 50.8% to 5.7%, desflurane increased from 25.6% to 77.0%, and antiemetic prophylaxis from 6.5% to 50.8%. Median [IQR] recovery time decreased from 72 [50, 102] to 62 [44, 90] minutes, P <0.001. Supplemental analyses found antiemetic prophylaxis was associated with PONV reduction (OR = 0.47, 95% CI 0.38 -0.58, P < 0.001). When compared to isoflurane, desflurane was associated with a decreased rate of respiratory depression (OR = 0.72, 95% CI 0.55-0.93, P = 0.013). Patients administered midazolam trended towards higher rate of respiratory depression (OR = 1.27, 95% CI 1.00-1.60, P = 0.050). CONCLUSIONS: Introduction of an anesthetic protocol that was designed to attenuate adverse anesthetic effects was associated with a reduction of anesthetic recovery time.

Perioperative blood product administration and thromboembolic events in patients with treated polycythemia vera: a case-control study.

BACKGROUND: Patients with polycythemia vera (PV) have historically been considered to be at high risk for perioperative hemorrhagic and thromboembolic complications. However, no recent studies have compared these outcomes between treated PV patients and patients without PV undergoing similar procedures. STUDY DESIGN AND METHODS: Patients with PV who underwent surgery with anesthesia from June 1, 2006, to May 31, 2011, were randomly matched (sex, age, type of surgical procedure, surgical year) at a ratio of 1:4 with control patients without PV. Conditional logistic regression analysis adjusting for surgical duration, preoperative hemoglobin, platelet count, and cardiovascular disease was used to assess the association between PV and blood product transfusions, thromboembolism, and other major cardiovascular and pulmonary complications. RESULTS: Fifty-six PV patients who underwent 79 surgeries were matched with 312 controls. During hospitalization, 35 (44.3%) and 82 (25.9%) PV and control patients, respectively, were transfused with blood products. PV patients were at increased risk for transfusion intraoperatively (odds ratio [OR], 4.35; 95% confidence interval [CI], 1.79-10.57; p = 0.001) and during hospitalization (OR, 4.35; 95% CI, 1.84-10.31; p < 0.001). The likelihood of thromboembolic complications and/or other major complications did not differ between the two study groups (thromboembolic-OR 1.53, 95% CI 0.39-6.02, p = 0.540; other major complications-OR 2.15, 95% CI 0.93-4.96, p = 0.073). CONCLUSIONS: Medically managed PV patients had an increased likelihood of receiving blood products perioperatively. Given the low number of observed thromboembolic events, we cannot make definitive conclusions regarding the association between PV and thromboembolism.

Characteristics of emergency pages using a computer-based anesthesiology paging system in children and adults undergoing procedures at a tertiary care medical center.

BACKGROUND: In our large academic supervisory practice, attending anesthesiologists concomitantly care for multiple patients. To manage communications within the procedural environment, we use a proprietary electronic computer-based anesthesiology visual paging system. This system can send an emergency page that instantly alerts the attending anesthesiologist and other available personnel that immediate help is needed. We analyzed the characteristics of intraoperative emergency pages in children and adults. METHODS: We identified all emergency page activations between January 1, 2005 and July 31, 2010 in our main operating rooms. Electronic medical records were reviewed for rates and characteristics of pages such as primary etiology, performed interventions, and outcomes. RESULTS: During the study period, 258,135 anesthetics were performed (n = 32,103 children, younger than 18 years) and 370 emergency pages (n = 309 adults, n = 61 children) were recorded (1.4 per 1000 cases; 95% confidence interval, 1.3-1.6). Infants had the highest rates (9.4 per 1000; 95% confidence interval, 5.7-14.4) of emergency page activations (P < 0.001 compared with each other age group). In adults, the most frequent causes were hemodynamic (55%), and in children respiratory and airway (60.7%) events. CONCLUSION: Emergency pages were rare in patients older than 2 years. Infants were more likely than children 1 to 2 years of age to have emergency page activation, despite both groups being cared for by pediatric fellowship trained anesthesiologists.

Nonalcoholic steatohepatitis in bariatric patients with a diagnosis of obstructive sleep apnea.

OBJECTIVE: To study a possible association between obstructive sleep apnea (OSA) severity, managed with noninvasive ventilation, and nonalcoholic steatohepatitis (NASH) in bariatric surgical patients. METHODS: Medical records of 218 bariatric surgical patients who underwent liver biopsy were reviewed. OSA severity was determined from preoperative polysomnography (apnea-hypopnea index (AHI) ≤ 15 no/mild OSA vs. AHI ≥ 16 moderate/severe OSA). Patients diagnosed with OSA were prescribed noninvasive ventilation. Patients were categorized according to liver histopathology into 3 groups: (i) no liver disease or simple steatosis, (ii) mild NASH (steatosis with necroinflammation and mild fibrosis (stage 0-1)), and iii) advanced NASH (steatosis with necroinflammation and more advanced fibrosis (stage ≥ 2)). RESULTS: 125 patients (57%) had no/mild OSA, and 93 (43%) had moderate/severe OSA. There was no difference in serum aminotransferases between patients by OSA severity classification. There was a high prevalence of hepatic histopathological abnormalities: 84% patients had steatosis, 57% had necroinflammation, 34% had fibrotic changes, and 14% had advanced NASH. There was no association between severity of NASH and severity of OSA. CONCLUSIONS: There is no association between stage of steatohepatitis and OSA severity among morbidly obese patients managed with noninvasive ventilation.

Kidney injury during pregnancy: associated comorbid conditions and outcomes.

PURPOSE: To investigate the characteristics of women who have kidney injury during pregnancy. METHODS: Medical records of all women who gave birth at our institution between January 1, 2005, and December 31, 2010, were retrospectively reviewed electronically. We identified those who incurred a kidney injury [defined by modified Acute Kidney Injury Network (AKIN) criteria: serum creatinine (sCr) increase ≥0.3 mg/dL] during pregnancy or within 30 days postpartum. Identified case records were reviewed in detail. RESULTS: During the study period, 54 women had a kidney injury (0.4 % estimated incidence) with a mean (SD) increase in sCr of 0.46 (0.29) mg/dL; most injuries were AKIN stage 1 with transient increases in sCr. Most of the women (n = 48, 87.3 %) had substantial preexisting or pregnancy-associated comorbid conditions (e.g., kidney disease, hypertension, diabetes), complications (e.g., preeclampsia, HELLP syndrome), or a complicated obstetric course (hemorrhage, infections) that could have contributed to the development of a kidney injury. Two patients had AKIN stage 3 injuries: a previously healthy patient who had a massive hemorrhage during cesarean delivery, and a patient with a renal transplant who had deterioration and eventual postpartum failure of her transplanted kidney. CONCLUSIONS: The majority of pregnancy-associated kidney injuries were transient and occurred in women with substantial comorbid conditions or complicated pregnancies.

Postoperative emergency response team activation at a large tertiary medical center.

OBJECTIVE: To study characteristics and outcomes associated with emergency response team (ERT) activation in postsurgical patients discharged to regular wards after anesthesia. PATIENTS AND METHODS: We identified all ERT activations that occurred within 48 hours after surgery from June 1, 2008, through December 31, 2009, in patients discharged from the postanesthesia care unit to regular wards. For each ERT case, up to 2 controls matched for age (±10 years), sex, and type of procedure were identified. A chart review was performed to identify factors that may be associated with ERT activation. RESULTS: We identified 181 postoperative ERT calls, 113 (62%) of which occurred within 12 hours of discharge from the postanesthesia care unit, for an incidence of 2 per 1000 anesthetic administrations (0.2%). Multiple logistic regression analysis revealed the following factors to be associated with increased odds for postoperative ERT activation: preoperative central nervous system comorbidity (odds ratio [OR], 2.53; 95% confidence interval [CI], 1.20-5.32; P=.01), preoperative opioid use (OR, 2.00; 95% CI, 1.30-3.10; P=.002), intraoperative use of phenylephrine infusion (OR, 3.05; 95% CI, 1.08-8.66; P=.04), and increased intraoperative fluid administration (per 500-mL increase, OR, 1.06; 95% CI, 1.01-1.12; P=.03). ERT patients had longer hospital stays, higher complication rates, and increased 30-day mortality compared with controls. CONCLUSION: Preoperative opioid use, history of central neurologic disease, and intraoperative hemodynamic instability are associated with postoperative decompensation requiring ERT intervention. Patients with these clinical characteristics may benefit from discharge to progressive or intensive care units in the early postoperative period.

Nonalcoholic steatohepatitis (NASH) does not increase complications after laparoscopic bariatric surgery.

BACKGROUND: Advanced liver disease is associated with increased risk for postoperative complications. It is not well known whether the presence of nonalcoholic steatohepatitis (NASH) in morbidly obese patients contributes to the rate of postoperative complications. The main objective was to study the association between NASH and postoperative complications in bariatric patients. METHODS: A total of 340 contemporary sequential patients who underwent laparoscopic bariatric operations and who had intraoperative liver biopsies were studied. The rates of severe postoperative complications were compared across three patient groups-those with (1) no liver disease or with simple steatosis, (2) mild nonalcoholic NASH [steatosis with necroinflammation and mild fibrosis (stage 0-1)], and (3) advanced NASH [steatosis, necroinflammation, and more advanced fibrosis (stage ≥ 2)]. RESULTS: Of 340 patients, 141 (42%) had no NASH, and 151 (44%) and 48 (14%) had mild and advanced NASH, respectively. Superobesity (P = 0.037), diabetes (P < 0.001), and cerebrovascular disease (P = 0.013) had highest frequencies in patients with advanced NASH. Hypertension was highly prevalent in cohort (57%) but similarly distributed across three groups. Forty-five patients experienced at least one complication (pulmonary 4, cardiovascular 8, surgical 16, and acute kidney injury 21). The complications rate did not differ significantly across NASH categories. Median hospital stay was 3 days (IQR 2, 3), and it was not associated with NASH severity. There were no 30-day postoperative deaths. CONCLUSIONS: Despite the high prevalence of NASH among morbidly obese surgical patients, this condition was not associated with increased risk for postoperative complications. Postoperative acute kidney injury was the most frequent single complications.

Allergic reactions during anesthesia at a large United States referral center.

BACKGROUND: The types of agents implicated to trigger intraoperative anaphylactic reactions vary among reports, and there are no recent series from the United States. In this retrospective study, we examined perioperative anaphylactic reactions that occurred at a major tertiary referral academic center. METHODS: To characterize perioperative allergens associated with anaphylactic reactions, we reviewed the Mayo Clinic Division of Allergic Diseases skin test database between 1992 to 2010. The records of all patients who were tested for perioperative and anesthetic medications were reviewed. Charts that included a detailed history obtained by an allergist, skin test results, and tryptase measurements when available were reviewed and categorized. RESULTS: Thirty-eight patients were found to have an anaphylactic reaction during anesthesia, of which 18 were immunoglobulin (Ig)E-mediated anaphylactic reactions (likely causative agent identified by skin test), 6 were non-IgE-mediated anaphylactic reactions (elevated tryptase levels and negative skin test), and 14 were probable non-IgE-mediated anaphylactic reactions (tryptase levels normal or not obtained and negative skin test). Of the IgE-mediated anaphylactic reactions, antibiotics were the most prevalent likely causative agent (50%) whereas neuromuscular blocking drugs were implicated as a likely causative agent in 11% of reactions. CONCLUSION: Antibiotics were the most common likely causative agent associated with IgE-mediated anaphylactic reactions; however, for 52.6% of reactions, a causative agent could not be determined, suggesting a non-IgE-mediated anaphylactic reaction. The undiagnosed allergic reactions place patients at risk of a subsequent reexposure to the same allergen, or lead to unnecessary avoidance of needed medications.

Anesthetic management of patients with Brugada syndrome: a case series and literature review.

PURPOSE: To review the anesthetic management and perioperative outcomes of patients diagnosed with Brugada syndrome (BrS) who were treated at a single centre and to compare those results with a comprehensive review of the existing literature. CLINICAL FEATURES: A retrospective chart review of anesthesia records from patients diagnosed with BrS at the Mayo Clinic was undertaken with the emphasis on administered drugs, ST segment changes, and occurrence of complications, including death, hemodynamic instability, and dysrhythmias. Eight patients were identified who underwent a total of 17 operative procedures from 2000 through 2010. A total of 20 significant ST segment elevations were recorded in four patients, several of which occurred in close temporal relation to anesthetic drug administration. These elevations resolved uneventfully. There were no recorded dysrhythmias, and recovery from anesthesia proceeded uneventfully. A literature review of patients with BrS yielded 52 anesthetics in 43 patients. The only recorded complications included unmasking of a Brugada ECG pattern, one episode of polymorphic ventricular tachycardia, which converted spontaneously to sinus rhythm, and one episode of postoperative ventricular fibrillation in the setting of epidural anesthesia. CONCLUSIONS: In this series and in the literature, BrS patients tolerated anesthesia without untoward disease-related complications. Propofol and local anesthetics carry a theoretical risk of arrhythmogenic potential in BrS patients, but clear evidence is lacking. However, awareness of their potential to induce arrhythmias warrants caution, especially with propofol infusions. Factors that might exacerbate ST segment elevations and subsequently lead to dysrhythmias (e.g., hyperthermia, bradycardia, and electrolyte imbalances, such as hyper- and hypokalemia and hypercalcemia) should be avoided or corrected.

Use of lean and six sigma methodology to improve operating room efficiency in a high-volume tertiary-care academic medical center.

BACKGROUND: Operating rooms (ORs) are resource-intense and costly hospital units. Maximizing OR efficiency is essential to maintaining an economically viable institution. OR efficiency projects often focus on a limited number of ORs or cases. Efforts across an entire OR suite have not been reported. Lean and Six Sigma methodologies were developed in the manufacturing industry to increase efficiency by eliminating non-value-added steps. We applied Lean and Six Sigma methodologies across an entire surgical suite to improve efficiency. STUDY DESIGN: A multidisciplinary surgical process improvement team constructed a value stream map of the entire surgical process from the decision for surgery to discharge. Each process step was analyzed in 3 domains, ie, personnel, information processed, and time. Multidisciplinary teams addressed 5 work streams to increase value at each step: minimizing volume variation; streamlining the preoperative process; reducing nonoperative time; eliminating redundant information; and promoting employee engagement. Process improvements were implemented sequentially in surgical specialties. Key performance metrics were collected before and after implementation. RESULTS: Across 3 surgical specialties, process redesign resulted in substantial improvements in on-time starts and reduction in number of cases past 5 pm. Substantial gains were achieved in nonoperative time, staff overtime, and ORs saved. These changes resulted in substantial increases in margin/OR/day. CONCLUSIONS: Use of Lean and Six Sigma methodologies increased OR efficiency and financial performance across an entire operating suite. Process mapping, leadership support, staff engagement, and sharing performance metrics are keys to enhancing OR efficiency. The performance gains were substantial, sustainable, positive financially, and transferrable to other specialties.

Preoperative evaluation of patients with history of allergy to penicillin: comparison of 2 models of practice.

OBJECTIVE: To study whether allergy consultation and penicillin allergy skin testing affects the selection of antibacterial prophylaxis perioperatively in surgical patients with history of allergy to penicillin (HOAP). PATIENTS AND METHODS: From January 1 through June 30, 2004, we compared 2 different models of practice at our institution. At the Preoperative Evaluation Clinic (POEC), all patients with HOAP are evaluated by an allergist and undergo skin testing for allergy to penicillin. At other (non-POEC) preoperative evaluation settings (OPES), patients with HOAP do not undergo allergy consultation and penicillin skin testing before surgery. Of the 4889 patients screened at the POEC during the study period, 412 consecutive patients with HOAP were included in the study. Of the 416 patients screened at OPES, 69 consecutive patients with HOAP were studied. Logistic regression was used to assess whether allergy consultation was associated with the choice of antibiotic for antibacterial prophylaxis perioperatively, after adjusting for age, sex, and type of surgery. RESULTS: Perioperative cephalosporin use was greater among patients screened at POEC vs those screened at OPES (70% vs 39%, P<.001 unadjusted; P=.04 adjusted for age, sex, and type of surgery). Vancomycin use was lower for patients screened at POEC vs those screened at OPES (10% vs 28%, P<.001 unadjusted; P=.03 adjusted). CONCLUSION: For patients with HOAP, evaluation at the POEC was associated with increased use of cephalosporin and decreased use of vancomycin.

Does low-dose droperidol administration increase the risk of drug-induced QT prolongation and torsade de pointes in the general surgical population?

BACKGROUND: The US Food and Drug Administration issued a black box warning regarding the use of droperidol and the potential for torsade de pointes (TdP). METHODS: The primary objective of this retrospective study was to determine whether low-dose droperidol administration increased the incidence of TdP in the general surgical population during a 3-yr time period before and after the Food and Drug Administration black box warning. A random sample of 150 surgical patients during each time interval was selected to estimate the droperidol use for each time period. RESULTS: During the time period before the black box warning (July 1, 1998 to June 30, 2001), 2,321/139,932 patients (1.66%) had QT prolongation, TdP, or death within 48 h after surgery. We could identify no patients who clearly developed TdP before the black box warning. There was one patient for whom the cause of death could not positively be ruled out as due to TdP. In the time period after the black box warning (July 1, 2002 to June 30, 2005), 2,207 patients (1.46%) had documented QT prolongation, TdP, or death within 48 h after surgery, including only two cases (<0.1%) of TdP. The incidence of droperidol exposure was approximately 12% (exact 95% confidence interval, 7.3-18.3%) before the black box warning and 0% after placement of the black box warning on droperidol. Therefore, we estimate that approximately 16,791 patients (95% confidence interval, 10,173-25,607) were exposed to droperidol, none of whom experienced documented TdP. CONCLUSIONS: This indicates that the Food and Drug Administration black box warning for low dose droperidol is excessive and unnecessary.