Increased left ventricular myocardial mass is associated with arrhythmias after cardiac surgery.

OBJECTIVES: The purpose of this study was to investigate whether patients with an elevated left ventricular mass index undergoing cardiac surgery were more likely to experience postoperative atrial and ventricular arrhythmias. DESIGN: A retrospective analysis. SETTING: A single tertiary care university hospital. PARTICIPANTS: One thousand consecutive patients undergoing all types of adult cardiac surgery. INTERVENTIONS: With institutional review board approval, intraoperative transesophageal echocardiographic images were reviewed by a single reviewer. The left ventricular mass index was calculated using the American Society of Echocardiography-recommended formula. Medical charts were reviewed for the occurrence and type of clinically significant postoperative arrhythmias. MEASUREMENTS AND RESULTS: Of the patients who had an elevated left ventricular mass index, 47.6% (225/473) developed clinically significant postoperative arrhythmias compared with 38.3% (142/371) of patients with a normal left ventricular mass index (odds ratio [OR] = 1.46; 95% confidence interval [CI], 1.11-1.93; p = 0.007). In the multivariate analysis, this finding remained statistically significant, controlling for the effects of age, weight, sex, surgery type, left ventricular function, functional status, left atrial dimensions, and a history of atrial fibrillation (OR = 1.40; 95% CI, 1.03-1.90 per 100-g/m(2) increase in the left ventricular mass index). An increased left ventricular mass index was also an independent predictor of the separate or combined occurrence of atrial or ventricular arrhythmias. CONCLUSIONS: An elevated left ventricular mass index was a strong independent predictor of clinically significant postoperative atrial and ventricular arrhythmias after adult cardiac surgery. Although prospective validation is required, targeting patients for arrhythmia prophylaxis therapy may be justified in patients with a left ventricular mass index >188 g/m(2).

Factors affecting the decision to defer endotracheal extubation after surgery for congenital heart disease: a prospective observational study.

BACKGROUND: Fast-tracking and early endotracheal extubation have been described in patients undergoing surgery for congenital heart disease (CHD); however, criteria for patient selection have not been validated in a prospective manner. Our goal in this study was to prospectively identify factors associated with the decision to defer endotracheal extubation in the operating room (OR). METHODS: We performed a prospective observational study of 275 patients (median age 18 months) at the Mount Sinai Medical Center (MSMC), New York, New York, and 49 patients (median age 25 months) at the University of Tokyo Hospital (UTH), Tokyo, Japan, undergoing surgery for CHD requiring cardiopulmonary bypass. These patients were all eligible for fast-tracking, including extubation in the OR immediately after surgery, according to the respective inclusion/exclusion criteria applied at the 2 sites. RESULTS: Eighty-nine percent of patients at the MSMC, and 65% of patients at the UTH were extubated in the OR. At the MSMC, all patients without aortic cross-clamp, and patients with simple procedures (Risk Adjustment for Congenital Heart Surgery [RACHS] score 1) were extubated in the OR. Among the remaining MSMC patients, regression analysis showed that procedure complexity was still an independent predictor for not proceeding with planned extubation in the OR. Extubation was more likely to be deferred in the RACHS score 3 surgical risk patients compared with the RACHS score 2 group (P = 0.005, odds ratio 3.8 [CI: 1.5, 9.7]). Additionally, trisomy 21 (P = 0.0003, odds ratio 9.9 [CI: 2.9, 34.5]) and age (P = 0.0015) were significant independent predictors for deferring OR extubation. We tested our findings on the patients from the UTH by developing risk categories from the MSMC data that ranked eligible patients according to the chance of OR extubation. The risk categories proved to predict endotracheal extubation in the 49 patients who had undergone surgery at the UTH relative to their overall extubation rate, despite differences in anesthetic regimen and inclusion/exclusion criteria. CONCLUSIONS: Preoperatively known factors alone can predict the relative chances of deferring extubation after surgery for CHD. The early extubation strategies applied in the 2 centers were successful in the majority of cases.

A mission-based productivity compensation model for an academic anesthesiology department.

INTRODUCTION: We replaced a nearly fixed-salary academic physician compensation model with a mission-based productivity model with the goal of improving attending anesthesiologist productivity. METHODS: The base salary system was stratified according to rank and clinical experience. The supplemental pay structure was linked to electronic patient records and a scheduling database to award points for clinical activity; educational, research, and administrative points systems were constructed in parallel. We analyzed monthly American Society of Anesthesiologist (ASA) unit data for operating room activity and physician compensation from 2000 through mid-2007, excluding the 1-yr implementation period (July 2004-June 2005) for the new model. RESULTS: Comparing 2005-2006 with 2000-2004, quarterly ASA units increased by 14% (P = 0.0001) and quarterly ASA units per full-time equivalent increased by 31% (P < 0.0001), while quarterly ASA units per anesthetizing location decreased by 10% (P = 0.046). Compared with a baseline year (2001), Instructor and Assistant Professor faculty compensation increased more than Associate Professor and Professor faculty (P < 0.001) in both pre- and postimplementation periods. There were larger compensation increases for the postimplementation period compared with preimplementation across faculty rank groupings (P < 0.0001). Academic and educational output was stable. DISCUSSION: Implementing a productivity-based faculty compensation model in an academic department was associated with increased mean supplemental pay with relatively fewer faculty. ASA units per month and ASA units per operating room full-time equivalent increased, and these metrics are the most likely drivers of the increased compensation. This occurred despite a slight decrease in clinical productivity as measured by ASA units per anesthetizing location. Academic and educational output was stable.

The effect of an interactive visual reminder in an anesthesia information management system on timeliness of prophylactic antibiotic administration.

BACKGROUND: To reduce the incidence of surgical site infection, preoperative antibiotics should be administered within 60 min before surgical incision. The purpose of this study was to determine whether adding a visual interactive electronic reminder with a message related to antibiotic administration to our anesthesia information management system would increase compliance with prophylactic antibiotic guidelines. METHODS: We retrospectively studied electronic anesthesia records of ambulatory and day-of-surgery admission surgical cases in which one of our usual prophylactic antibiotics was administered from June 2004 through December 2005, an interval that includes cases both before and after the February 2005 implementation of the new reminder. Compliance was defined as documented antibiotic administration within 60 min before the surgical procedure starting time. Noncompliant cases were divided into those in which dosing was too early or too late. RESULTS: Compliance for 4987 cases before and 9478 cases after the reminder was implemented increased from 82.4% to 89.1% (P < 0.01). This increase was found both for attending anesthesiologists assisted by a resident or nurse anesthetist (82.9% before vs 89.1% after, P < 0.01) and for attending anesthesiologists working alone (80.1% before vs 89.3% after, P < 0.01). The improvement in compliance was associated with a decrease in the incidence of antibiotics administered too late (i.e., after surgical incision) (15.2% before vs 8.1% after, P < 0.01), but with no significant change in the incidence of antibiotics administered too early (i.e., more than 60 min before skin incision) (2.4% before vs 2.8% after, P = 0.07). CONCLUSIONS: The implementation of a visual interactive electronic reminder regarding administration of preoperative antibiotics in an anesthesia information management system was associated with a sustained increase in compliance with surgical prophylactic antibiotic administration timing guidelines.

Changing patterns of postoperative nausea and vomiting prophylaxis drug use in an academic anesthesia practice.

STUDY OBJECTIVE: To characterize the evolution of postoperative nausea and vomiting (PONV) prophylactic drug use. DESIGN: Retrospective data extraction and analysis of electronic anesthesia records. SETTING: Anesthesia department of an urban academic medical center. MEASUREMENTS: 144,134 anesthetics given by 57 attending anesthesiologists were studied. Administered doses of droperidol, ondansetron, dexamethasone, and metoclopramide were tabulated for each year for each practitioner. MAIN RESULTS: Ondansetron use in the periods before and after the Food and Drug Administration (FDA) warning concerning droperidol was 8% and 35%, respectively. Use of PONV prophylaxis increased for all included patient and anesthetic factors. Among those who used droperidol before the revised FDA warning, 61% stopped using it altogether. Afterwards, 75% (27-100%) of droperidol use was in combination with another agent. CONCLUSIONS: We found a significant and sustained decrease in droperidol use after the FDA-mandated labeling revision. We also found a significant increase in ondansetron use--an increase that exceeded the amount needed to substitute for the decreased droperidol use. The changes may be related to multiple factors, including the FDA warning, a trend toward more PONV prophylaxis, and the increasing predominance of serotonin antagonists for this indication.

Interscalene regional anesthesia for arthroscopic shoulder surgery: a safe and effective technique.

There has been resistance to the use of interscalene regional block for arthroscopic shoulder surgery because of concerns about potential complications and failed blocks with the subsequent need for general anesthesia. The purpose of this study was to assess whether interscalene regional block is safe and effective and offers many advantages over general anesthesia for outpatient arthroscopic shoulder surgery. Through a retrospective chart review of consecutive arthroscopic shoulder surgeries over a 2.5-year time period, in a tertiary university medical center with an anesthesiology residency, 277 interscalene blocks (96%) were successful; 12 (4%) required general anesthesia because of an inadequate block. There were no seizures, pneumothoraces, cardiac events, or other major complications. There was a 1% rate of minor complications, all of which were transient sensory neuropathies that resolved within 5 weeks on average. We conclude that interscalene block can provide effective anesthesia for arthroscopic shoulder surgery.

Interscalene regional anesthesia for shoulder surgery.

BACKGROUND: Despite a trend toward the use of regional anesthesia for orthopaedic procedures, there has been resistance to the use of interscalene regional block for shoulder surgery because of concerns about failed blocks and potential complications. METHODS: We retrospectively reviewed the cases of 568 consecutive patients who had shoulder surgery under interscalene regional block in a tertiary-care, university-based practice with an anesthesiology residency program. The blocks were performed by a group of anesthesiologists who were dedicated to the concept of regional anesthesia in their practice. Complete anesthetic and orthopaedic records were available for 547 patients. The surgical procedure, planned type of anesthesia, occurrence of block failure, and the presence of complications were noted. RESULTS: Of the 547 patients, 295 underwent an arthroscopic procedure and 252 (including eighty who had an arthroplasty) underwent an open procedure. General anesthesia was the initial planned choice for sixty-nine patients because of the complexity or duration of the procedure, the anatomic location, or patient insistence. Thirty-four of the sixty-nine patients also received an interscalene regional block. Interscalene regional block alone was planned for 478 patients. A total of 462 patients (97%) had a successful block whereas sixteen required general anesthesia because the block was inadequate. The success of the block was independent of the type or length of the surgery. No patient had a seizure, pneumothorax, cardiac event, or other major complication. Twelve (2.3%) of the 512 patients who had a block had minor complications, which included sensory neuropathy in eleven patients and a complex regional pain syndrome that resolved at three months in one patient. For ten of the eleven patients, the neuropathy had resolved by six months. CONCLUSIONS: Interscalene regional block provides effective anesthesia for most types of shoulder surgery, including arthroplasty and fracture fixation. When administered by an anesthesiologist committed to and skilled in the technique, the block has an excellent rate of success and is associated with a relatively low complication rate.

Noninvasive cerebral oxygenation may predict outcome in patients undergoing aortic arch surgery.

OBJECTIVES: Surgical repair of the aortic arch remains technically challenging and is associated with considerable morbidity and mortality. Cerebral oximetry is a noninvasive technology that can monitor the regional oxygen saturation of the frontal cortex. We hypothesized that magnitude and duration of decreased intraoperative regional oxygen saturation was associated with postoperative organ dysfunction. Additionally, we sought to identify regional oxygen saturation threshold values that are predictive of organ dysfunction. METHODS: The intraoperative regional oxygen saturation values of 30 patients undergoing aortic arch surgery were recorded and analyzed. Postoperative complications were categorized as "major" and "minor." Severe adverse outcome, extubation time, intensive care unit length of stay, and hospital length of stay data were collected and compared with the integrals of regional oxygen saturation and time (area under the threshold) spent beneath predetermined absolute threshold limits. RESULTS: Twenty subjects underwent hemiarch replacement, and 10 subjects received total aortic arch replacements. There were 30 major and 29 minor complications identified. Sixteen (53.3%) patients had at least 1 major complication. Logistic regression showed statistically significant associations between area under the threshold and severe adverse outcome incidence for regional oxygen saturation thresholds of 60% (P = .038) and 65% (P = .025). Patients who spent more than 30 minutes under the absolute threshold of 60% had an extended hospital stay of 4 days leading to an additional cost of $8300.00. CONCLUSIONS: Our findings lend evidence to support the association of decreased perioperative cerebral oxygenation values with poor outcomes after aortic arch surgery.

Predictive model for postoperative delirium in cardiac surgical patients.

Delirium is a common complication following cardiac surgery, and the predictors of delirium remain unclear. The authors performed a prospective observational analysis to develop a predictive model for postoperative delirium using demographic and procedural parameters. A total of 112 adult postoperative cardiac surgical patients were evaluated twice daily for delirium using the Richmond Agitation-Sedation Scale (RASS) and Confusion Assessment Model for the ICU (CAM-ICU). The incidence of delirium was 34% (n = 38). Increased age (odds ratio [OR] = 2.5; 95% confidence interval [CI] = 1.6-3.9; P < .0001, per 10 years) and increased duration of surgery (OR = 1.3; 95% CI = 1.1-1.5; P = .0002, per 30 minutes) were independently associated with postoperative delirium. Gender, BMI, diabetes mellitus, preoperative ejection fraction, surgery type, length of cardiopulmonary bypass, intraoperative blood component administration, Acute Physiology and Chronic Health Evaluation II score, Sequential Organ Failure Assessment score, and Charlson Comorbidity Index, were not independently associated with postoperative delirium.

Extraction and mapping of drug names from free text to a standardized nomenclature.

Free text fields are often used to store clinical drug data in electronic health records. The use of free text facilitates rapid data entry by the clinician. Errors in spelling, abbreviations, and jargon, however, limit the utility of these data. We designed and implemented an algorithm, using open source tools and RxNorm, to extract and normalize drug data stored in free text fields of an anesthesia electronic health record. The algorithm was developed using a training set containing drug data from 49,518 cases, and validated using a validation set containing data from 14,655 cases. Overall sensitivity and specificity for the validation set were 92.2% and 95.7% respectively. The mains sources of error were misspellings and unknown but valid drug names. These preliminary results demonstrate that free text clinical drug data can be efficiently extracted and mapped to a controlled drug nomenclature.

Development of a module for point-of-care charge capture and submission using an anesthesia information management system.

BACKGROUND: The use of electronic charge vouchers in anesthesia practice is limited, and the effects on practice management are unreported. The authors hypothesized that the new billing technology would improve the effectiveness of the billing interface and enhance financial practice management measures. METHODS: A custom application was created to extract billing elements from the anesthesia information management system. The application incorporates business rules to determine whether individual cases have all required elements for a complete and compliant bill. The metrics of charge lag and days in accounts receivable were assessed before and after the implementation of the electronic charge voucher system. RESULTS: The average charge lag decreased by 7.3 days after full implementation. The total days in accounts receivable, controlling for fee schedule changes and credit balances, decreased by 10.1 days after implementation, representing a one-time revenue gain equivalent to 3.0% of total annual receipts. There are additional ongoing cost savings related to reduction of personnel and expenses related to paper charge voucher handling. CONCLUSIONS: Anesthesia information management systems yield financial and operational benefits by speeding up the revenue cycle and by reducing direct costs and compliance risks related to the billing and collection processes. The observed reductions in charge lag and days in accounts receivable may be of benefit in calculating the return on investment that is attributable to the adoption of anesthesia information management systems and electronic charge transmission.

Multi-platforms medical computer systems integration.

Presently, software architects face the challenge of integrating and linking different application software packages built on different computer platforms. Often they inherit various systems, ranging from mainframe to PDA-based applications. The first stage before programming different interfaces is to identify the means of communications most suitable for particular systems. The experience of the Mount Sinai Medical Center in New York, which combines a hospital, a healthcare network, a research center and a medical school, illustrates common problems faced by a number of medical institutions. This paper will discuss the various options, including the Internet, software architects have, and how they can use them during the development of an infrastructure for health care systems.

Predictors of hypotension after induction of general anesthesia.

Hypotension after induction of general anesthesia is a common event. In the current investigation, we sought to identify the predictors of clinically significant hypotension after the induction of general anesthesia. Computerized anesthesia records of 4096 patients undergoing general anesthesia were queried for arterial blood pressure (BP), demographic information, preoperative drug history, and anesthetic induction regimen. The median BP was determined preinduction and for 0-5 and 5-10 min postinduction of anesthesia. Hypotension was defined as either: mean arterial blood pressure (MAP) decrease of >40% and MAP <70 mm Hg or MAP <60 mm Hg. Overall, 9% of patients experienced severe hypotension 0-10 min postinduction of general anesthesia. Hypotension was more prevalent in the second half of the 0-10 min interval after anesthetic induction (P < 0.001). In 2406 patients with retrievable outcome data, prolonged postoperative stay and/or death was more common in patients with versus those without postinduction hypotension (13.3% and 8.6%, respectively, multivariate P < 0.02). Statistically significant multivariate predictors of hypotension 0-10 min after anesthetic induction included: ASA III-V, baseline MAP <70 mm Hg, age > or =50 yr, the use of propofol for induction of anesthesia, and increasing induction dosage of fentanyl. Smaller doses of propofol, etomidate, and thiopental were not associated with less hypotension. To avoid severe hypotension, alternatives to propofol anesthetic induction (e.g., etomidate) should be considered in patients older than 50 yr of age with ASA physical status > or =3. We conclude that it is advisable to avoid propofol induction in patients who present with baseline MAP <70 mm Hg.

Pre-donation assessment of kidneys by magnetic resonance angiography and venography: accuracy and impact on outcomes.

Reports on the accuracy of magnetic resonance angiography (MRA) and magnetic resonance venography (MRV) in evaluating living donor renovasculature employ few patients or omit the consequences of inaccurate scans. We retrospectively compared intraoperative findings to MRA/MRV scans in 146 donor-recipient pairs. For detecting accessory arteries and early branching, MRA sensitivity was 57.6%, specificity 96.5%, false positive rate 3.5%, false negative rate 42.4%, positive predictive value 82.6%, negative predictive value 88.6% and overall accuracy 87.7%. By excluding clinically inconsequential accessory arteries, MRA sensitivity rose to 73.1%, specificity to 96.7% and overall accuracy to 92.5%. For MRVs, sensitivity was 56.2%, specificity 99%, false positive rate 1%, false negative rate 43.8%, positive predictive value 90%, negative predictive value 94.8% and accuracy 94.5%. Inaccurate scans were associated with prolonged donor and recipient operations and more frequently reconstructed arteries, but did not affect clinical outcomes. Because most missed accessory arteries are inconsequential, MRA is a useful, less invasive method for defining donor renovascular anatomy.

Computerized case history--an effective tool for management of patients and clinical trials.

UNLABELLED: Monitoring diagnostic procedures, treatment protocols and clinical outcome are key issues in maintaining quality medical care and in evaluating clinical trials. For these purposes, a user-friendly computerized method for monitoring all available information about a patient is needed. OBJECTIVE: To develop a real-time computerized data collection system for verification, analysis and storage of clinical information on an individual patient. METHODS: Data was integrated on a single time axis with normalized graphics. Laboratory data was set according to standard protocols selected by the user and diagnostic images were integrated as needed. The system automatically detects variables that fall outside established limits and violations of protocols, and generates alarm signals.Results. The system provided an effective tool for detection of medical errors, identification of discrepancies between therapeutic and diagnostic procedures, and protocol requirements. CONCLUSIONS: The computerized case history system allows collection of medical information from multiple sources and builds an integrated presentation of clinical data for analysis of clinical trials and for patient follow-up.

The anesthetic considerations in patients with ventricular assist devices presenting for noncardiac surgery: a review of eight cases.

IMPLICATIONS: The number of patients supported by ventricular assist devices (VADs) that present for noncardiac surgery is increasing in our institution. Our recent experience with eight such patients is reported, along with a review of the most commonly implanted VADs and the anesthetic implications and considerations for VAD-supported patients undergoing noncardiac surgery.

Association of intraoperative hypotension and pulmonary hypertension with adverse outcomes after orthotopic liver transplantation.

BACKGROUND: Various preoperative, surgical, and postoperative markers of impaired outcome after orthotopic liver transplantation have been reported, but the influence of intraoperative hemodynamic aberrations has not been thoroughly investigated. SETTING: University Hospital.Study design Retrospective cohort analysis. METHODS: The authors retrospectively reviewed computerized anesthesia records to determine associations between occurrences of abnormally low or high mean pulmonary artery pressure (MPAP), cardiac output, heart rate, systolic arterial pressure, diastolic arterial pressure, and mean arterial pressure (MAP) with negative surgical outcome. Negative surgical outcome was defined as poor early graft function, primary graft nonfunction, or death attributable to hemodynamic causes. RESULTS: Of 789 patients, 142 (18.0%) had negative surgical outcome. Controlling for the influence of United Network for Organ Sharing (UNOS) status > 1, long operation time, cold donor organ ischemia time, and donor age, the only hemodynamic parameters that were independently associated with negative surgical outcome were MAP < 40 mmHg at least once during the procedure (odds ratio [OR] 2.39, p = 0.0016) and MPAP > 40 mmHg at least 3 times during the procedure (OR 2.2, p = 0.035). The occurrence of MAP < 40 mmHg was temporally associated with donor graft reperfusion. Hepatic artery thromboses were not associated with hemodynamic aberrations. CONCLUSIONS: Hemodynamic events are independently associated with adverse outcomes after orthotopic liver transplantation.

Intraoperative tachycardia and hypertension are independently associated with adverse outcome in noncardiac surgery of long duration.

UNLABELLED: Relatively little is known about the influence of intraoperative hemodynamic variables on surgical outcomes. We drew subjects (n = 797) from a study of patients undergoing major noncardiac surgery. The physiological component of the POSSUM (Physiological and Operative Severity Score for the enUmeration of Mortality) operative risk stratification index was determined, and intraoperative measurements of heart rate (HR), mean arterial blood pressure, and systolic arterial blood pressure (SAP) were retrieved from computerized anesthesia records. For every 5-min epoch during the surgery, HR, mean arterial blood pressure, and SAP were each classified as low, normal, or high. Negative surgical outcome (NSO) was defined as a hospital stay of >10 days with a morbid condition or death during the hospital stay. Statistical analyses included Mantel-Haenszel tests and multiple logistic regression. There was no significant association between hemodynamic variables and NSO with short operations. In 388 patients with operations longer than the median time of 220 min, NSO occurred in 15.6%. Controlling for POSSUM score and operation time beyond 220 min, both high HR (odds ratio, 2.704; P = 0.01) and high SAP (odds ratio, 2.095; P = 0.009) were associated with NSO in longer operations. Thus, intraoperative tachycardia and hypertension were associated independently with adverse outcomes after major noncardiac surgery of long duration, over and above the risk imparted by underlying medical conditions. IMPLICATIONS: Intraoperative tachycardia and hypertension were associated with negative postoperative outcomes after major noncardiac surgery of long duration. These results imply that intraoperative tachycardia and hypertension may have independent effects on outcome over and above the risk imparted by underlying medical conditions.