Showing papers in "Survey of Anesthesiology in 2000"

Missed Diagnoses of Acute Cardiac Ischemia in the Emergency Department

Abstract: BACKGROUND Discharging patients with acute myocardial infarction or unstable angina from the emergency department because of missed diagnoses can have dire consequences. We studied the incidence of, factors related to, and clinical outcomes of failure to hospitalize patients with acute cardiac ischemia. METHODS We analyzed clinical data from a multicenter, prospective clinical trial of all patients with chest pain or other symptoms suggesting acute cardiac ischemia who presented to the emergency departments of 10 U.S. hospitals. RESULTS Of 10,689 patients, 17 percent ultimately met the criteria for acute cardiac ischemia (8 percent had acute myocardial infarction and 9 percent had unstable angina), 6 percent had stable angina, 21 percent had other cardiac problems, and 55 percent had noncardiac problems. Among the 889 patients with acute myocardial infarction, 19 (2.1 percent) were mistakenly discharged from the emergency department (95 percent confidence interval, 1.1 to 3.1 percent); among the 966 patients with unstable angina, 22 (2.3 percent) were mistakenly discharged (95 percent confidence interval, 1.3 to 3.2 percent). Multivariable analysis showed that patients who presented to the emergency department with acute cardiac ischemia were more likely not to be hospitalized if they were women less than 55 years old (odds ratio for discharge, 6.7; 95 percent confidence interval, 1.4 to 32.5), were nonwhite (odds ratio, 2.2; 1.1 to 4.3), reported shortness of breath as their chief symptom (odds ratio, 2.7; 1.1 to 6.5), or had a normal or nondiagnostic electrocardiogram (odds ratio, 3.3; 1.7 to 6.3). Patients with acute infarction were more likely not to be hospitalized if they were nonwhite (odds ratio for discharge, 4.5; 95 percent confidence interval, 1.8 to 11.8) or had a normal or nondiagnostic electrocardiogram (odds ratio, 7.7; 95 percent confidence interval, 2.9 to 20.2). For the patients with acute infarction, the risk-adjusted mortality ratio for those who were not hospitalized, as compared with those who were, was 1.9 (95 percent confidence interval, 0.7 to 5.2), and for the patients with unstable angina, it was 1.7 (95 percent confidence interval, 0.2 to 17.0). CONCLUSIONS The percentage of patients who present to the emergency department with acute myocardial infarction or unstable angina who are not hospitalized is low, but the discharge of such patients is associated with increased mortality. Failure to hospitalize is related to race, sex, and the absence of typical features of cardiac ischemia. Continued efforts to reduce the number of missed diagnoses are warranted.

Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration: Application to Healthy Patients Undergoing Elective Procedures

Abstract: P RACTICE Guidelines are systematically developed recommendations that assist the practitioner and patient in making decisions about health care. These recommendations may be adopted, modified, or rejected according to clinical needs and constraints and are not intended to replace local institutional policies. In addition, Practice Guidelines developed by the American Society of Anesthesiologists (ASA) are not intended as standards or absolute requirements, and their use cannot guarantee any specific outcome. Practice Guidelines are subject to revision as warranted by the evolution of medical knowledge, technology, and practice. They provide basic recommendations that are supported by a synthesis and analysis of the current literature, expert and practitioner opinion, open forum commentary, and clinical feasibility data. This update includes data published since the Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration were adopted by the ASA in 1998 and published in 1999.*

Effect of Mechanical Ventilation on Inflammatory Mediators in Patients with Acute Respiratory Distress Syndrome: A Randomized Controlled Trial

Abstract: ContextStudies have shown that an inflammatory response may be elicited by mechanical ventilation used for recruitment or derecruitment of collapsed lung units or to overdistend alveolar regions, and that a lung-protective strategy may reduce this response.ObjectiveTo test the hypothesis that mechanical ventilation induces a pulmonary and systemic cytokine response that can be minimized by limiting recruitment or derecruitment and overdistention.Design and SettingRandomized controlled trial in the intensive care units of 2 European hospitals from November 1995 to February 1998, with a 28-day follow-up.PatientsForty-four patients (mean [SD] age, 50 [18] years) with acute respiratory distress syndrome were enrolled, 7 of whom were withdrawn due to adverse events.InterventionsAfter admission, volume-pressure curves were measured and bronchoalveolar lavage and blood samples were obtained. Patients were randomized to either the control group (n=19): tidal volume to obtain normal values of arterial carbon dioxide tension (35-40 mm Hg) and positive end-expiratory pressure (PEEP) producing the greatest improvement in arterial oxygen saturation without worsening hemodynamics; or the lung-protective strategy group (n=18): tidal volume and PEEP based on the volume-pressure curve. Measurements were repeated 24 to 30 and 36 to 40 hours after randomization.Main Outcome MeasuresPulmonary and systemic concentrations of inflammatory mediators approximately 36 hours after randomization.ResultsPhysiological characteristics and cytokine concentrations were similar in both groups at randomization. There were significant differences (mean [SD]) between the control and lung-protective strategy groups in tidal volume (11.1 [1.3] vs 7.6 [1.1] mL/kg), end-inspiratory plateau pressures (31.0 [4.5] vs 24.6 [2.4] cm H2O), and PEEP (6.5 [1.7] vs 14.8 [2.7] cm H2O) (P<.001). Patients in the control group had an increase in bronchoalveolar lavage concentrations of interleukin (IL) 1β, IL-6, and IL-1 receptor agonist and in both bronchoalveolar lavage and plasma concentrations of tumor necrosis factor (TNF) α, IL-6, and TNF-α receptors over 36 hours (P<.05 for all). Patients in the lung-protective strategy group had a reduction in bronchoalveolar lavage concentrations of polymorphonuclear cells, TNF-α, IL-1β, soluble TNF-α receptor 55, and IL-8, and in plasma and bronchoalveolar lavage concentrations of IL-6, soluble TNF-α receptor 75, and IL-1 receptor antagonist (P<.05). The concentration of the inflammatory mediators 36 hours after randomization was significantly lower in the lung-protective strategy group than in the control group (P<.05).ConclusionsMechanical ventilation can induce a cytokine response that may be attenuated by a strategy to minimize overdistention and recruitment/derecruitment of the lung. Whether these physiological improvements are associated with improvements in clinical end points should be determined in future studies.

Effects of Controlled-Release Metoprolol on Total Mortality, Hospitalizations, and Well-being in Patients with Heart Failure: The Metoprolol CR/XL Randomized Intervention Trial in Congestive Heart Failure (MERIT-HF)

Abstract: Åke Hjalmarson, MD, PhD Sidney Goldstein, MD Björn Fagerberg, MD, PhD Hans Wedel, PhD Finn Waagstein, MD, PhD John Kjekshus, MD, PhD John Wikstrand, MD, PhD Dia El Allaf, MD Jirı́ Vı́tovec, MD, PhD Jan Aldershvile, MD, PhD Matti Halinen, MD, PhD Rainer Dietz, MD Karl-Ludwig Neuhaus, MD András Jánosi, MD, DSc Gudmundur Thorgeirsson, MD, PhD Peter H. J. M. Dunselman, MD, PhD Lars Gullestad, MD Jerzy Kuch, MD Johan Herlitz, MD, PhD Peter Rickenbacher, MD Stephen Ball, MD, PhD Stephen Gottlieb, MD Prakash Deedwania, MD for the MERIT-HF Study Group

Association of Aortic-Valve Sclerosis with Cardiovascular Mortality and Morbidity in the Elderly

Abstract: Background Although aortic-valve stenosis is clearly associated with adverse cardiovascular outcomes, it is unclear whether valve sclerosis increases the risk of cardiovascular events. Methods We assessed echocardiograms obtained at base line from 5621 men and women 65 years of age or older who were enrolled in a population-based prospective study. On echocardiography, the aortic valve was normal in 70 percent (3919 subjects), sclerotic without outflow obstruction in 29 percent (1610), and stenotic in 2 percent (92). The subjects were followed for a mean of 5.0 years to assess the risk of death from any cause and of death from cardiovascular causes. Cardiovascular morbidity was defined as new episodes of myocardial infarction, angina pectoris, congestive heart failure, or stroke. Results There was a stepwise increase in deaths from any cause (P for trend, <0.001) and deaths from cardiovascular causes (P for trend, <0.001) with increasing aortic-valve abnormality; the respective rates were 14.9 and 6.1 per...

Can Postoperative Nausea and Vomiting Be Predicted

Abstract: BackgroundRetrospective [1] studies fail to identify predictors of postoperative nausea and vomiting (PONV). The authors prospectively studied 17,638 consecutive outpatients who had surgery to identify these predictors.MethodsData on medical conditions, anesthesia, surgery, and PONV were collected i

Effect of Statins on Risk of Coronary Disease: A Meta-analysis of Randomized Controlled Trials

Abstract: ContextLowering low-density lipoprotein cholesterol (LDL-C) is known to reduce risk of recurrent coronary heart disease in middle-aged men. However, this effect has been uncertain in elderly people and women.ObjectiveTo estimate the risk reduction of coronary heart disease and total mortality associated with statin drug treatment, particularly in elderly individuals and women.Data SourcesTrials published in English-language journals were retrieved by searching MEDLINE (1966–December 1998), bibliographies, and authors' reference files.Study SelectionStudies in which participants were randomized to statin or control treatment for at least 4 years and clinical disease or death was the primary outcome were included in the meta-analysis (5 of 182 initially identified).Data ExtractionInformation on sample size, study drug duration, type and dosage of statin drug, participant characteristics at baseline, reduction in lipids during intervention, and outcomes was abstracted independently by 2 authors (J.H. and S.V.) using a standardized protocol. Disagreements were resolved by consensus.Data SynthesisData from the 5 trials, with 30,817 participants, were included in this meta-analysis. The mean duration of treatment was 5.4 years. Statin drug treatment was associated with a 20% reduction in total cholesterol, 28% reduction in LDL-C, 13% reduction in triglycerides, and 5% increase in high-density lipoprotein cholesterol. Overall, statin drug treatment reduced risk 31% in major coronary events (95% confidence interval [CI], 26%-36%) and 21% in all-cause mortality (95% CI, 14%-28%). The risk reduction in major coronary events was similar between women (29%; 95% CI, 13%-42%) and men (31%; 95% CI, 26%-35%), and between persons aged at least 65 years (32%; 95% CI, 23%-39%) and persons younger than 65 years (31%; 95% CI, 24%-36%).ConclusionsOur meta-analysis indicates that reduction in LDL-C associated with statin drug treatment decreases the risk of coronary heart disease and all-cause mortality. The risk reduction was similar for men and women and for elderly and middle-aged persons.

Coronary Angioplasty With or Without Stent Implantation for Acute Myocardial Infarction

Abstract: BACKGROUND Coronary-stent implantation is frequently performed for treatment of acute myocardial infarction. However, few studies have compared stent implantation with primary angioplasty alone. METHODS We designed a multicenter study to compare primary angioplasty with angioplasty accompanied by implantation of a heparin-coated Palmaz-Schatz stent. Patients with acute myocardial infarction underwent emergency catheterization and angioplasty. Those with vessels suitable for stenting were randomly assigned to undergo angioplasty with stenting (452 patients) or angioplasty alone (448 patients). RESULTS The mean (+/-SD) minimal luminal diameter was larger after stenting than after angioplasty alone (2.56+/-0.44 mm vs. 2.12+/-0.45 mm, P<0.001), although fewer patients assigned to stenting had grade 3 blood flow (according to the classification of the Thrombolysis in Myocardial Infarction trial) (89.4 percent, vs. 92.7 percent in the angioplasty group; P=0.10). After six months, fewer patients in the stent group than in the angioplasty group had angina (11.3 percent vs. 16.9 percent, P=0.02) or needed target-vessel revascularization because of ischemia (7.7 percent vs. 17.0 percent, P<0.001). In addition, the combined primary end point of death, reinfarction, disabling stroke, or target-vessel revascularization because of ischemia occurred in fewer patients in the stent group than in the angioplasty group (12.6 percent vs. 20.1 percent, P<0.01). The decrease in the combined end point was due entirely to the decreased need for target-vessel revascularization. The six-month mortality rates were 4.2 percent in the stent group and 2.7 percent in the angioplasty group (P=0.27). Angiographic follow-up at 6.5 months demonstrated a lower incidence of restenosis in the stent group than in the angioplasty group (20.3 percent vs. 33.5 percent, P<0.001). CONCLUSIONS In patients with acute myocardial infarction, routine implantation of a stent has clinical benefits beyond those of primary coronary angioplasty alone.

The Effect of Bisoprolol on Perioperative Mortality and Myocardial Infarction in High-Risk Patients Undergoing Vascular Surgery

Abstract: A BSTRACT Background Cardiovascular complications are the most important causes of perioperative morbidity and mortality among patients undergoing major vascular surgery. Methods We performed a randomized, multicenter trial to assess the effect of perioperative blockade of beta-adrenergic receptors on the incidence of death from cardiac causes and nonfatal myocardial infarction within 30 days after major vascular surgery in patients at high risk for these events. High-risk patients were identified by the presence of both clinical risk factors and positive results on dobutamine echocardiography. Eligible patients were randomly assigned to receive standard perioperative care or standard care plus perioperative beta-blockade with bisoprolol. Results A total of 1351 patients were screened, and 846 were found to have one or more cardiac risk factors. Of these 846 patients, 173 had positive results on dobutamine echocardiography. Fifty-nine patients were randomly assigned to receive bisoprolol, and 53 to receive standard care. Fifty-three patients were excluded from randomization because they were already taking a beta-blocker, and eight were excluded because they had extensive wall-motion abnormalities either at rest or during stress testing. Two patients in the bisoprolol group died of cardiac causes (3.4 percent), as compared with nine patients in the standard-care group (17 percent, P=0.02). Nonfatal myocardial infarction occurred in nine patients given standard care only (17 percent) and in none of those given standard care plus bisoprolol (P<0.001). Thus, the primary study end point of death from cardiac causes or nonfatal myocardial infarction occurred in 2 patients in the bisoprolol group (3.4 percent) and 18 patients in the standard-care group (34 percent, P<0.001). Conclusions Bisoprolol reduces the perioperative incidence of death from cardiac causes and nonfatal myocardial infarction in high-risk patients who are undergoing major vascular surgery. (N Engl J Med 1999;341:1789-94.)

Nerve Injury Associated with Anesthesia: A Closed Claims Analysis

Abstract: Claims against anesthesiologists for eye injuries were analyzed as part of the ASA Closed Claims Project. Eye injury occurred in 3% of all claims in the database (71 of 2,046). The payment frequency for eye injury claims was higher than that for non-eye injury claims (70% vs. 56%; P less than or equal to 0.05). The median cost of eye injury claims was less than that for other claims ($24,000 vs. $95,000; P less than or equal to 0.01). Two distinct subsets were identified. The first was characterized by corneal abrasion during general anesthesia (25 of 71 claims; 35%). Claims for corneal abrasion were characterized by low incidence of permanent injury (16%) and low median payment ($3,000). Reviewers were able to identify a mechanism of injury in only 20% of claims for corneal abrasion. The second subset of eye injury was characterized by patient movement during ophthalmologic surgery (21 of 71; 30%). Blindness was the outcome in all cases. Sixteen of the claims involving movement occurred during general anesthesia, and 5 occurred during monitored anesthesia care. The median payment for claim involving movement was 10 times greater than for non-movement claims ($90,000 vs. $9,000; P less than or equal to 0.01). Anesthesiologist reviewers deemed the care rendered in the general anesthesia "movement" claims as meeting standards in only 19% of claims. From the perspective of patient safety, as well as risk management, these data suggest two specific needs: research directed at better understanding of the etiology of corneal abrasion and clinical strategies designed to assure patient immobility during ophthalmic surgery.

Peripartum Cardiomyopathy: National Heart, Lung, and Blood Institute and Office of Rare Diseases (National Institutes of Health) Workshop Recommendations and Review

Abstract: Objective Peripartum cardiomyopathy (PPCM) is a rare life-threatening cardiomyopathy of unknown cause that occurs in the peripartum period in previously healthy women. In April 1997, the National Heart, Lung, and Blood Institute (NHLBI) and the Office of Rare Diseases of the National Institutes of Health (NIH) convened a Workshop on Peripartum Cardiomyopathy to foster a systematic review of information and to develop recommendations for research and education. Participants Fourteen workshop participants were selected by NHLBI staff and represented cardiovascular medicine, obstetrics, immunology, and pathology. A representative subgroup of 8 participants and NHLBI staff formed the writing group for this article and updated the literature on which the conclusions were based. The workshop was an open meeting, consistent with NIH policy. Evidence Data presented at the workshop were augmented by a MEDLINE search for English-language articles published from 1966 to July 1999, using the terms peripartum cardiomyopathy, cardiomyopathy, and pregnancy. Articles on the epidemiology, pathogenesis, pathophysiology, diagnosis, treatment, and prognosis of PPCM were included. RECOMMENDATION PROCESS: After discussion of data presented, workshop participants agreed on a standardized definition of PPCM, a general clinical approach, and the need for a registry to provide an infrastructure for future research. Conclusions Peripartum cardiomyopathy is a rare lethal disease about which little is known. Diagnosis is confined to a narrow period and requires echocardiographic evidence of left ventricular systolic dysfunction. Symptomatic patients should receive standard therapy for heart failure, managed by a multidisciplinary team. If subsequent pregnancies occur, they should be managed in collaboration with a high-risk perinatal center. Systematic data collection is required to answer important questions about incidence, treatment, and prognosis.

Long-Term Benefit of Primary Angioplasty as Compared with Thrombolytic Therapy for Acute Myocardial Infarction

Abstract: The treatment of myocardial infarction has evolved considerably over the past decades. Reported mortality rates have fallen, due to a variety of factors, including earlier diagnosis and treatment of the acute event, improved management of complications such as recurrent ischaemia and heart failure, and widespread availability of pharmacological therapies such as aspirin, beta-blockers and ACE inhibitors. Most attention, however, has been focused on therapies that restore antegrade coronary blood flow in the culprit vessel of the patient with evolving acute myocardial infarction. The two methods to achieve this goal are intravenous thrombolytic therapy most often followed by a conservative approach of watchful waiting, or immediate coronary angiography followed by primary angioplasty if appropriate. An overview of short term results of 10 randomized comparisons between these two approaches has shown that compared to thrombolysis, primary angioplasty results in a lower mortality (4·4% vs 6·5%, relative risk 0·66, 95% confidence intervals 0·46–0·94), translating into an absolute benefit of two lives saved per 100 patients treated with angioplasty rather than thrombolysis. The relative reduction in death or non-fatal reinfarction after angioplasty compared to thrombolysis is even more striking (7·2% vs 11·9%, relative risk 0·58, 95% confidence intervals 0·44–0·76). With respect to safety, stroke was reduced from 2·0% with thrombolysis to 0·7% with angioplasty (relative risk 0·35, 95% confidence intervals 0·14–0·77). However, considerable uncertainty existed about the long-term relative merits of these two approaches. We recently published long-term follow-up data of 395 patients randomly assigned to treatment with angioplasty or intravenous streptokinase. Clinical information was collected for a mean ( SD) of 5 2 years, and medical charges were compared. A total of 194 patients were assigned to undergo angioplasty and 201 to receive streptokinase. Mortality was 13% in the angioplasty group, as compared with 24% in the streptokinase group (relative risk 0·54, 95% confidence intervals 0·36–0·87). Non-fatal reinfarction

The Unreliability of Individual Physician “Report Cards” for Assessing the Costs and Quality of Care of a Chronic Disease

Abstract: ContextPhysician profiling is widely used by many health care systems, but little is known about the reliability of commonly used profiling systems.ObjectivesTo determine the reliability of a set of physician performance measures for diabetes care, one of the most common conditions in medical practice, and to examine whether physicians could substantially improve their profiles by preferential patient selection.Design and SettingCohort study performed from 1990 to 1993 at 3 geographically and organizationally diverse sites, including a large staff-model health maintenance organization, an urban university teaching clinic, and a group of private-practice physicians in an urban area.ParticipantsA total of 3642 patients with type 2 diabetes cared for by 232 different physicians.Main Outcome MeasuresPhysician profiles for their patients' hospitalization and clinic visit rates, total laboratory resource utilization rate and level of glycemic control by average hemoglobin A1c level with and without detailed case-mix adjustment.ResultsFor profiles based on hospitalization rates, visit rates, laboratory utilization rates, and glycemic control, 4% or less of the overall variance was attributable to differences in physician practice and the reliability of the median physician's case-mix–adjusted profile was never better than 0.40. At this low level of physician effect, a physician would need to have more than 100 patients with diabetes in a panel for profiles to have a reliability of 0.80 or better (while more than 90% of all primary care physicians at the health maintenance organization had fewer than 60 patients with diabetes). For profiles of glycemic control, high outlier physicians could dramatically improve their physician profile simply by pruning from their panel the 1 to 3 patients with the highest hemoglobin A1clevels during the prior year. This advantage from gaming could not be prevented by even detailed case-mix adjustment.ConclusionsPhysician "report cards" for diabetes, one of the highest-prevalence conditions in medical practice, were unable to detect reliably true practice differences within the 3 sites studied. Use of individual physician profiles may foster an environment in which physicians can most easily avoid being penalized by avoiding or deselecting patients with high prior cost, poor adherence, or response to treatments.

Comparison of Transmyocardial Revascularization With Medical Therapy in Patients with Refractory Angina

Abstract: BACKGROUND Transmyocardial revascularization involves the creation of channels in the myocardium with a laser to relieve angina. We compared the safety and efficacy of transmyocardial revascularization performed with a holmium laser with those of medical therapy in patients with refractory class IV angina (according to the criteria of the Canadian Cardiovascular Society). METHODS In a prospective study conducted between March 1996 and July 1998 at 18 centers, 275 patients with medically refractory class IV angina and coronary disease that could not be treated with percutaneous or surgical revascularization were randomly assigned to receive transmyocardial revascularization followed by continued medical therapy (132 patients) or medical therapy alone (143 patients). RESULTS After one year of follow-up, 76 percent of the patients who had undergone transmyocardial revascularization had improvement in angina (a reduction of two or more classes), as compared with 32 percent of the patients who received medical therapy alone (P<0.001). Kaplan-Meier survival estimates at one year (based on an intention-to-treat analysis) were similar for the patients assigned to undergo transmyocardial revascularization and those assigned to receive medical therapy alone (84 percent and 89 percent, respectively; P=0.23). At one year, the patients in the transmyocardial-revascularization group had a significantly higher rate of survival free of cardiac events (54 percent, vs. 31 percent in the medical-therapy group; P<0.001), a significantly higher rate of freedom from treatment failure (73 percent vs. 47 percent, P<0.001), and a significantly higher rate of freedom from cardiac-related rehospitalization (61 percent vs. 33 percent, P<0.001). Exercise tolerance and quality-of-life scores were also significantly higher in the transmyocardial-revascularization group than in the medical-therapy group (exercise tolerance, 5.0 MET [metabolic equivalent] vs. 3.9 MET; P=0.05); quality-of-life score, 21 vs. 12; P=0.003). However, there were no differences in myocardial perfusion between the two groups, as assessed by thallium scanning. CONCLUSIONS Patients with refractory angina who underwent transmyocardial revascularization and received continued medical therapy, as compared with similar patients who received medical therapy alone, had a significantly better outcome with respect to improvement in angina, survival free of cardiac events, freedom from treatment failure, and freedom from cardiac-related rehospitalization.

The Association Between Hospital Volume and Survival After Acute Myocardial Infarction in Elderly Patients

Abstract: Background Patients with chest pain thought to be due to acute coronary ischemia are typically taken by ambulance to the nearest hospital. The potential benefit of field triage directly to a hospital that treats a large number of patients with myocardial infarction is unknown. Methods We conducted a retrospective cohort study of the relation between the number of Medicare patients with myocardial infarction that each hospital in the study treated (hospital volume) and long-term survival among 98,898 Medicare patients 65 years of age or older. We used proportional-hazards methods to adjust for clinical, demographic, and health-system–related variables, including the availability of invasive procedures, the specialty of the attending physician, and the area of residence of the patient (rural, urban, or metropolitan). Results The patients in the quartile admitted to hospitals with the lowest volume were 17 percent more likely to die within 30 days after admission than patients in the quartile admitted to hos...

Meta-Analysis of Trials Comparing β-Blockers, Calcium Antagonists, and Nitrates for Stable Angina

Abstract: ContextWhich drug is most effective as a first-line treatment for stable angina is not known.ObjectiveTo compare the relative efficacy and tolerability of treatment with β-blockers, calcium antagonists, and long-acting nitrates for patients who have stable angina.Data SourcesWe identified English-language studies published between 1966 and 1997 by searching the MEDLINE and EMBASE databases and reviewing the bibliographies of identified articles to locate additional relevant studies.Study SelectionRandomized or crossover studies comparing antianginal drugs from 2 or 3 different classes (β-blockers, calcium antagonists, and long-acting nitrates) lasting at least 1 week were reviewed. Studies were selected if they reported at least 1 of the following outcomes: cardiac death, myocardial infarction, study withdrawal due to adverse events, angina frequency, nitroglycerin use, or exercise duration. Ninety (63%) of 143 identified studies met the inclusion criteria.Data ExtractionTwo independent reviewers extracted data from selected articles, settling any differences by consensus. Outcome data were extracted a third time by 1 of the investigators. We combined results using odds ratios (ORs) for discrete data and mean differences for continuous data. Studies of calcium antagonists were grouped by duration and type of drug (nifedipine vs nonnifedipine).Data SynthesisRates of cardiac death and myocardial infarction were not significantly different for treatment with β-blockers vs calcium antagonists (OR, 0.97; 95% confidence interval [CI], 0.67-1.38; P=.79). There were 0.31 (95% CI, 0.00-0.62; P=.05) fewer episodes of angina per week with β-blockers than with calcium antagonists. β-Blockers were discontinued because of adverse events less often than were calcium antagonists (OR, 0.72; 95% CI, 0.60-0.86; P<.001). The differences between β-blockers and calcium antagonists were most striking for nifedipine (OR for adverse events with β-blockers vs nifedipine, 0.60; 95% CI, 0.47-0.77). Too few trials compared nitrates with calcium antagonists or β-blockers to draw firm conclusions about relative efficacy.Conclusionsβ-Blockers provide similar clinical outcomes and are associated with fewer adverse events than calcium antagonists in randomized trials of patients who have stable angina.

Improved Clinical Outcome After Widespread Use of Coronary-Artery Stenting in Canada

Abstract: BACKGROUND The introduction and refinement of coronary-artery stenting dramatically changed the practice of percutaneous coronary revascularization in the mid-1990s. We analyzed one-year follow-up data for all percutaneous coronary interventions performed in a large, unselected population in Canada to determine whether the use of coronary stenting has been associated with improved outcomes. METHODS Prospectively collected data on all percutaneous coronary interventions performed on residents of British Columbia, Canada, between April 1994 and June 1997 were linked to province-wide health care data bases to provide the date of the following end points: subsequent target-vessel revascularization, myocardial infarction, and death. Baseline characteristics and procedural variables were identified and Kaplan-Meier survival curves were generated for 9594 procedures divided into seven groups, one for each sequential half-year period. RESULTS The overall burden of coexisting illnesses remained stable throughout the study period. A large increase in the rate of coronary stenting (from 14.2 percent in the period from April to June 1994 to 58.7 percent in the period from January to June 1997) was associated with a significant reduction in the rate of adverse cardiac events at one year (from 28.8 percent to 22.8.percent; adjusted relative risk, 0.79; 95 percent confidence interval, 0.69 to 0.90; P<0.001). This reduction in adverse events was exclusively due to a large reduction in subsequent target-vessel revascularization (from 24.4 percent to 17.0 percent; adjusted relative risk, 0.72; 95 percent confidence interval, 0.62 to 0.83; P<0.001) without significant changes in the overall rates of myocardial infarction (5.4 percent, P=0.28) or death (3.9 percent, P=0.65). CONCLUSIONS The need for target-vessel revascularization during one year of follow-up decreased after percutaneous coronary intervention during the mid-1990s. The reduction was coincident with the introduction and subsequent widespread use of coronary stenting.

The Effect of the Volume of Procedures at Transplantation Centers on Mortality After Liver Transplantation

Abstract: Background For many complex surgical procedures there is an association between a low volume of procedures and an increased risk of death for the patients who undergo the procedures. Methods We examined the effect of the volume of procedures at transplantation centers on the risk of death after liver transplantation. We analyzed all liver transplantations performed in the United States between October 1, 1987, and April 30, 1994. Because the results for 1987 to 1991 were largely similar to those from 1992 to 1994, we focused on the more recent period. Results Between January 1, 1992, and April 30, 1994, 47 centers performed 20 or fewer liver transplantations each per year (total, 837 transplantations) and were designated low-volume centers, and 52 centers performed more than 20 transplantations each per year (total, 6526) and were designated high-volume centers. The one-year mortality rate for the low-volume centers was 25.9 percent, as compared with 20.0 percent for the high-volume centers. Thirteen cent...

Gastrointestinal Toxicity of Nonsteroidal Antiinflammatory Drugs

Abstract: One hundred years have passed since Felix Hoffman, working at Bayer Industries, reported the successful synthesis of acetylsalicylic acid as the first nonsteroidal antiinflammatory drug (NSAID).1,2 At the suggestion of Hermann Dreser, Bayer's chief pharmacologist at the time,3 the compound was called “aspirin” and was purported to represent a convenient mechanism for the delivery of salicylic acid in the treatment of rheumatic diseases, menstrual pain, and fever.2 Approximately 40 years elapsed before Douthwaite and Lintott4 provided endoscopic evidence that aspirin could cause gastric mucosal damage. Numerous reports have corroborated this observation,5–8 and the introduction of more potent agents . . .

Effects of Admission to a Teaching Hospital on the Cost and Quality of Care for Medicare Beneficiaries

Abstract: Background and Methods We studied the effects of admission to a teaching hospital on the cost and quality of care for patients covered by Medicare (age, 65 years old or older). We used data from the National Long Term Care Survey and merged them with Medicare claims data. We selected the first hospitalization for hip fracture (802 patients), stroke (793), coronary heart disease (1007), or congestive heart failure (604) occurring between January 1, 1984, and December 31, 1994, and calculated all Medicare payments for inpatient and outpatient care during the six-month period after admission. Survival was assessed through 1995. Hospitals were classified as major or minor teaching hospitals (with minor hospitals defined as those in which the number of residents per bed was less than the median number for all teaching hospitals) or as private nonprofit, government (i.e., public), or private for-profit hospitals. Results Medicare payments for the six-month period after hospitalization were highest for patients ...

Initial Results from the National Registry for Juvenile-Onset Recurrent Respiratory Papillomatosis

Abstract: Objective To characterize the spectrum of juvenile-onset recurrent respiratory papillomatosis (RRP) in the United States and to obtain data about the natural course of the disease and its response to treatment. Setting Twenty tertiary-care pediatric otolaryngology centers throughout the United States. Patients All patients with active RRP aged less than 18 years at the participating sites. Main Outcome Measures Number of surgical procedures performed per year, progression of papillomas to previously nondiseased anatomical sites, drug interventions and other adjuvant therapy, and need for tracheostomy. Results Data were collected from 399 children enrolled from January 1, 1997, through December 31, 1998. There were 51.9% male; 62.7% white, 28.3% black, 9.0% other or unknown racial group; 10.8% Hispanic ethnicity. Mean age at diagnosis was 3.8 years (range, 0.1-16.3 years) and mean duration of disease was 4.4 years (range, 0.03-18.9 years). The mean number of surgical procedures per child was 4.4 per year (range, 0.2-19.3 per year). Children whose RRP was diagnosed at younger ages ( P =.001) and almost 2 times more likely to have 2 or more anatomical sites affected ( P =.008) than were children whose RRP was diagnosed at later ages (≥3.0 years), after adjusting for sex, race, and years of treatment. Conclusions Children whose disease was diagnosed before age 3 years were more likely than children aged 3 years or older to have more severe disease as measured by the mean number of surgical procedures performed and by the number of anatomical sites affected. The registry will form the basis for future analysis on the outcome of disease, natural course of RRP under management strategies, prevention strategies, and public health importance.

Positive End-Expiratory Pressure Improves Respiratory Function in Obese but Not in Normal Subjects During Anesthesia and Paralysis

Abstract: BACKGROUND Morbidly obese patients, during anesthesia and paralysis, experience more severe impairment of respiratory mechanics and gas exchange than normal subjects. The authors hypothesized that positive end-expiratory pressure (PEEP) induces different responses in normal subjects (n = 9; body mass index 40 kg/m2). METHODS The authors measured lung volumes (helium technique), the elastances of the respiratory system, lung, and chest wall, the pressure-volume curves (occlusion technique and esophageal balloon), and the intraabdominal pressure (intrabladder catheter) at PEEP 0 and 10 cm H2O in paralyzed, anesthetized postoperative patients in the intensive care unit or operating room after abdominal surgery. RESULTS At PEEP 0 cm H2O, obese patients had lower lung volume (0.59 +/- 0.17 vs. 2.15 +/- 0.58 l [mean +/- SD], P < 0.01); higher elastances of the respiratory system (26.8 +/- 4.2 vs. 16.4 +/- 3.6 cm H2O/l, P < 0.01), lung (17.4 +/- 4.5 vs. 10.3 +/- 3.2 cm H2O/l, P < 0.01), and chest wall (9.4 +/- 3.0 vs. 6.1 +/- 1.4 cm H2O/l, P < 0.01); and higher intraabdominal pressure (18.8 +/-7.8 vs. 9.0 +/- 2.4 cm H2O, P < 0.01) than normal subjects. The arterial oxygen tension was significantly lower (110 +/- 30 vs. 218 +/- 47 mmHg, P < 0.01; inspired oxygen fraction = 50%), and the arterial carbon dioxide tension significantly higher (37.8 +/- 6.8 vs. 28.4 +/- 3.1, P < 0.01) in obese patients compared with normal subjects. Increasing PEEP to 10 cm H2O significantly reduced elastances of the respiratory system, lung, and chest wall in obese patients but not in normal subjects. The pressure-volume curves were shifted upward and to the left in obese patients but were unchanged in normal subjects. The oxygenation increased with PEEP in obese patients (from 110 +/-30 to 130 +/- 28 mmHg, P < 0.01) but was unchanged in normal subjects. The oxygenation changes were significantly correlated with alveolar recruitment (r = 0.81, P < 0.01). CONCLUSIONS During anesthesia and paralysis, PEEP improves respiratory function in morbidly obese patients but not in normal subjects.

“Alveolar Recruitment Strategy” Improves Arterial Oxygenation During General Anaesthesia

Abstract: Abnormalities in gas exchange during general anaesthesia are caused partly by atelectasis. Inspiratory pressures of approximately 40 cm H2O are required to fully re-expand healthy but collapsed alveoli. However, without PEEP these re-expanded alveoli tend to collapse again. We hypothesized that an initial increase in pressure would open collapsed alveoli; if this inspiratory recruitment is combined with sufficient end-expiratory pressure, alveoli will remain open during general anaesthesia. We tested the effect of an 'alveolar recruitment strategy' on arterial oxygenation and lung mechanics in a prospective, controlled study of 30 ASA II or III patients aged more than 60 yr allocated to one of three groups. Group ZEEP received no PEEP. The second group received an initial control period without PEEP, and then PEEP 5 cm H2O was applied. The third group received an increase in PEEP and tidal volumes until a PEEP of 15 cm H2O and a tidal volume of 18 ml kg-1 or a peak inspiratory pressure of 40 cm H2O was reached. PEEP 5 cm H2O was then maintained. There was a significant increase in median PaO2 values obtained at baseline (20.4 kPa) and those obtained after the recruitment manoeuvre (24.4 kPa) at 40 min. This latter value was also significantly higher than PaO2 measured in the PEEP (16.2 kPa) and ZEEP (18.7 kPa) groups. Application of PEEP also had a significant effect on oxygenation; no such intra-group difference was observed in the ZEEP group. No complications occurred. We conclude that during general anaesthesia, the alveolar recruitment strategy was an efficient way to improve arterial oxygenation.

Ulnar Neuropathy in Surgical Patients

Abstract: BackgroundThe goal of this project was to study the frequency and natural history of perioperative ulnar neuropathy.MethodsA prospective evaluation of ulnar neuropathy in 1,502 adult patients undergoing noncardiac surgical procedures was performed. Patients were assessed with a standard questionnair

Relative Analgesic Potencies of Ropivacaine and Bupivacaine for Epidural Analgesia in Labor: Implications for Therapeutic Indexes

Abstract: Background The minimum local analgesic concentration (MLAC) has been defined as the median effective local analgesic concentration in a 20-ml volume for epidural analgesia in the first stage of labor. The aim of this study was to assess the relative analgesic potencies of epidural bupivacaine and ropivacaine by determining their respective minimum local analgesic concentrations. Methods Seventy-three parturients at Results The minimum local analgesic concentration of ropivacaine was 0.111% wt/vol (95% confidence interval, 0.100-0.122), and the minimum local analgesic concentration of bupivacaine was 0.067% wt/vol (95% confidence interval, 0.052-0.082). Ropivacaine was significantly less potent than bupivacaine, with a potency ratio of 0.6 (95% confidence interval, 0.49-0.74). No difference in motor effects was observed. Conclusion Ropivacaine was significantly less potent than bupivacaine for epidural analgesia in the first stage of labor.

Awareness During Anesthesia: A Closed Claims Analysis

Abstract: BackgroundAwareness during general anesthesia is a frightening experience, which may result in serious emotional injury and post-traumatic stress disorder. We performed an in-depth analysis of cases from the database of the American Society of Anesthesiologists Closed Claims Project to explore the c