The effect of changing transfusion practice on rates of perioperative stroke and myocardial infarction in patients undergoing carotid endarterectomy: a retrospective analysis of 1114 Mayo Clinic patients. Mayo Perioperative Outcomes Group.

OBJECTIVE: To evaluate changes in the institution's red blood cell (RBC) transfusion practice during the past 15 years and the influence of these changes on neurologic or cardiac morbidity after carotid endarterectomy. PATIENTS AND METHODS: Based on a retrospective analysis of the Mayo Clinic database, 1,114 patients who underwent carotid endarterectomy were stratified into 1 of 2 groups: (1) 1980 to 1985 (ie, pre-human immunodeficiency virus screening, early-practice group [n=552]) and (2) 1990 to 1995 (ie, recent-practice group [n=562]). Data were compared between time periods using the chi2 test for categorical variables and the rank sum test for continuous variables. Logistic regression was used to assess the association between perioperative transfusion practice and the occurrence of stroke or myocardial infarction. Two-tailed P values < or = 05 were considered statistically significant. RESULTS: Patients in the recent-practice group were significantly older (mean +/- SD age, 69.6 +/- 8.7 years) vs 65.9 +/- 8.3 years in the early-practice group (P<.001). The proportion of patients receiving perioperative RBC transfusion decreased dramatically from 72.9% in 1980-1985 to 8.7% in 1990-1995 (P<.001). Additionally, the mean +/- SD number of RBC units transfused decreased from 1.10 +/- 1.30 U in 1980-1985 to 0.27 +/- 1.22 U in 1990-1995 (P<.001). Mean +/- SD discharge hemoglobin concentration decreased from 13.7 +/- 1.4 g/dL in 1980-1985 to 11.8 +/- 1.5 g/dL in 1990-1995 (P<.001). Rates of perioperative stroke and myocardial infarction did not differ between the 2 time periods (early-practice group vs recent-practice group: stroke, 5.1% vs 3.6% [P=.22]; myocardial infarction, 1.5% vs 2.3% [P=.29]). CONCLUSIONS: Our results suggest that elderly patients undergoing carotid endarterectomy (ie, individuals known to be at high risk for cerebral and cardiac ischemia) can tolerate modest perioperative anemia despite a considerable change in the institution's transfusion practice (lower "transfusion trigger," the hemoglobin concentration or hematocrit value below which RBC transfusion is indicated).

Recruitment of house staff into anesthesiology: factors responsible for house staff selecting anesthesiology as a career and individual training program.

STUDY OBJECTIVE: To identify factors responsible in the selection of anesthesiology as a career by Mayo Clinic house staff (i.e., residents and clinical fellows); to evaluate their level of satisfaction with their choice of career and training program, and their perceptions of the future for anesthesiology trainees. DESIGN: Cross-sectional analysis using a questionnaire survey of 67 house staff enrolled in the anesthesiology training program during the 1995-1996 academic year. SETTING: Mayo Clinic, Rochester, MN. MEASUREMENTS AND MAIN RESULTS: Forty-eight (72%) of those surveyed responded to the questionnaire. Data were analyzed using the Chi-square and Mann-Whitney rank sum tests. A p-value less than or equal to 0.05 was considered statistically significant. The most frequently cited reasons for selecting anesthesiology as a career included the following: it is a "hands-on" specialty, it involves clinical application of physiology and pharmacology, and it provides immediate gratification in one's work. The most frequently cited reasons for selecting our training program were the diversity of training experience, prestige associated with Mayo Clinic, and employment opportunities following training. Forty-four (92%) felt downsizing of anesthesiology training programs was a national trend, 26 (54%) anticipated difficulty obtaining a job following training, and 16 (33%) felt they had future job security. Overall, 47 (98%) were happy with their career choice, and 40 (83%) would choose anesthesiology as a career if they were now graduating from medical school. All 1996 graduates found suitable employment without difficulty. CONCLUSIONS: Our data indicate that selection of a career in anesthesiology and training program are strongly associated with concerns regarding educational experiences and postgraduate employment opportunities.

Recruitment of House Staff into Anesthesiology: Factors Responsible for House Staff Selecting Anesthesiology as a Career and Individual Training Program.

Due to a variety of factors, there was a recent redistribution of graduating American medical students toward primary care specialties and a decline in the number of applicants seeking training positions in anesthesiology. In the present study, factors responsible for Mayo house staff (i.e., residents and clinical fellows) selecting anesthesiology as a career, and Mayo Clinic as their training program, were identified. We also evaluated their level of satisfaction with their choice of career and training program, and their perceptions of the future for anesthesiology trainees. A cross sectional analysis was conducted using a questionnaire to survey 67 house staff enrolled in the anesthesiology training program at Mayo Clinic, Rochester, MN during the 1995-1996 academic year. All responses were anonymous. Data were analyzed using the chi-square and Mann-Whitney rank sum tests. P ? 0.05 was considered statistically significant. Forty-eight (72%) of those surveyed responded to the questionnaire. The most frequently cited reasons for selecting anesthesiology as a career included it: is a "hands-on" specialty, involves clinical application of physiology and pharmacology, and provides immediate gratification in one's work. The most frequently cited reasons for selecting our training program were the diversity of training experience, prestige associated with Mayo Clinic, and employment opportunities following training. Forty-four (92%) felt downsizing of anesthesiology training programs was a national trend, 26 (54%) anticipated difficulty obtaining a job following training, and 16 (33%) felt they had future job security. Overall, 47 (98%) were happy with their career choice, and 40 (83%) would choose anesthesiology as a career if they were now graduating from medical school. Our data indicate that selection of a career in anesthesiology and training program are strongly associated with concerns regarding educational experiences and postgraduate employment opportunities. More than half anticipated difficulty obtaining postgraduate employment; however, this skepticism was overshadowed by two findings: the trainees reported a very high level of satisfaction in their choice of career and training program, and the vast majority reported they would seek a career in anesthesiology if they were now selecting a medical specialty. Additionally, all 1996 graduates found suitable employment without difficulty.

Venous air embolism in sitting and supine patients undergoing vestibular schwannoma resection.

OBJECTIVE: This study retrospectively compares the incidence of venous air embolism (VAE) detection and morbidity in the sitting and supine positions. All patients underwent vestibular schwannoma resection via the retrosigmoid approach by a single surgical team. METHODS: A total of 432 consecutive operations were reviewed, 222 of which were performed with the patients in the sitting position and 210 of which were performed with the patients in the supine position. Charts were reviewed for evidence of intraoperative VAE, intraoperative hypotension secondary to VAE, postoperative morbidity related to VAE, and other variables to compare the groups. RESULTS: This study demonstrated a 28% incidence of VAE detection when patients were in the sitting position compared to a 5% incidence of VAE detection when patients were in the supine position (P < 0.0001). Intraoperative hypotension secondary to VAE was noted in 1.8% of the sitting patients and 1.4% of the supine patients (P=0.72, no significant difference). Postoperative morbidity caused by VAE was noted in one sitting patient (0.5%) (pulmonary edema) and in no supine patients (P=0.48, no significant difference). Blood loss was slightly greater in the supine group, and operative times were similar in both groups, despite that the average tumor size of patients operated on in the sitting position was 2.8 cm versus 2.2 cm in the supine group (P < 0.0001). CONCLUSION: Our results indicate that although there is a higher incidence of VAE detection in sitting patients, the morbidity is not statistically greater. We conclude that because morbidity from VAE is similar in either position, patient positioning should be based on surgical team preference.

The effect of desflurane and isoflurane on cerebrospinal fluid pressure in humans with supratentorial mass lesions.

Desflurane, a new volatile anesthetic, produces cerebral vasodilation. The purpose of this study was to compare the effects of 1 MAC desflurane with those of isoflurane on cerebrospinal fluid pressure (CSFP) in patients with supratentorial mass lesions and a mass effect on computerized tomography (CT scan). Twenty adult patients undergoing craniotomy for removal of supratentorial mass lesions were studied. Ten patients received desflurane and 10 patients received isoflurane. Prior to induction of anesthesia, a radial artery catheter was inserted and a 19-G needle was inserted into the lumbar subarachnoid space to measure CSFP. Baseline arterial blood gases and CSFP were measured with the patient awake and unmedicated. Anesthesia was induced with thiopental (6-9 mg/kg) and muscle relaxation achieved with vecuronium (0.2 mg/kg). The lungs of all patients were hyperventilated to achieve an arterial CO2 tension of 24-28 mmHg. Anesthesia was maintained with 1 MAC volatile anesthetic, either 7.0% desflurane or 1.2% isoflurane in an air:O2 mixture to maintain an inspired O2 fraction (FIO2) of 0.50. Patients were not administered any other anesthetic until the dura was incised. Mean arterial pressure was kept within 20% of the patient's mean ward values with the use of esmolol or phenylephrine. CSFP, mean arterial pressure, end-tidal CO2 concentration (PETCO2), hemoglobin O2 saturation, and cerebral perfusion pressure were recorded with the patient awake, immediately postinduction with thiopental, postintubation, after institution of the volatile anesthetic, and every 5 min until the dura was incised. There was no difference in the mean (+/- SD) awake CSFP between the desflurane (11 +/- 4 mmHg) and the isoflurane (10 +/- 2 mmHg) groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Transfusion risks.

Hepatitis remains the most serious transfusion risk, in terms of incidence and severity. Transfusion-associated AIDS, hemolytic reactions, TRALI, and anaphylaxis are severe problems that occur relatively rarely, while febrile reactions and mild allergic reactions are common but not serious. The key to avoiding all these complications is autotransfusion (see the article "Autologous Transfusion" in this issue). Although intraoperative scavenging became available in many centers in the United States in the 1980s, it is hoped that pre-deposit autotransfusion will also become widely utilized in the next decade.

Status of the match in anesthesiology: 1988.

The majority of anesthesia program directors agreed 2 years ago to use the National Resident Matching Program (NRMP) as the mechanism for appointing senior medical students to second postgraduate year positions in anesthesiology. Eighty-seven applicants for the Mayo Clinic program were surveyed to measure the level of cooperation with the NRMP by programs and applicants. Low percentages of applicants reported pressures to sign contracts (22.4%) or make verbal commitments before February (32.8%). The frequency of these incidents was extremely low when considered in light of the number of applicant interviews reported by the applicants who responded. Nonparticipation in the match is a more important problem than infractions of NRMP rules.

A survey of transfusion practices among anesthesiologists.

A survey of transfusion practices was conducted among anesthesiologists practicing in the United States to determine if significant variation exists and to identify those areas toward which research and educational efforts should be directed. Thirty-seven percent (389) of 1,043 active members of the American Society of Anesthesiologists who received the survey responded. The indications for transfusion as well as the types of components administered were found to vary considerably. Among the areas which need to be addressed are arbitrary preoperative hemoglobin requirements, indications for fresh frozen plasma administration, preoperative blood ordering and autologous transfusion.

Sedation for stereotactic headframe application: a randomized comparison of two techniques.

A prospective, randomized study was performed in 87 patients to compare the safety, efficacy and dose requirements of two sedation techniques for stereotactic headframe application. Sedation administration and headframe application averaged 30 min. Fifty patients weighing 76 +/- 13 kg (mean +/- SD) received mean doses of 154 micrograms fentanyl plus 5.5 mg droperidol i.v. (FD group). An additional 37 patients weighing 76 +/- 19 kg received mean doses of 127 micrograms fentanyl plus 6.7 mg Valium (diazepam; FV group). Both treatments provided excellent hemodynamic stability and a low incidence of adverse side effects while providing adequate analgesia and sedation. The incidence of anesthetist-assessed patient anxiety and discomfort was more favorable in the FD group.

Complications of cerebral angiography: prospective assessment of risk.

A prospective study of 1,517 consecutive cerebral angiographic examinations is reported. The incidence of all complications was 8.5%, and the incidence of all neurologic complications was 2.6%. The overall incidence of permanent neurologic deficit was 0.33%. The incidence of permanent neurologic deficit in patients referred for evaluation of symptomatic cerebrovascular disease was 0.63%. Older age, increased serum creatinine concentration, and the use of more than one catheter all were significantly associated with serious neurologic complications. Although patients with a recent stroke or frequent transient ischemic attacks had a higher incidence of serious neurologic complications, this increase was not statistically significant for this sample.