Substance misuse amongst anaesthetists in the United Kingdom and Ireland. The results of a study commissioned by the Association of Anaesthetists of Great Britain and Ireland.

Three hundred and four departments of anaesthesia in UK and Ireland were sent questionnaires about alcohol and drug abuse in anaesthetists over the preceding 10-year period. Information was sought on the nature and extent of substance problems, their presentation and management. The survey achieved a high response rate of 71.7% and a total of 130 cases were reported, of whom 34.6% were consultants and 43.2% were trainees. Over 50% of respondents felt a lack of confidence in dealing with alcohol or drug misuse amongst colleagues. The results of this survey demonstrate that over one anaesthetist per month has presented with significant alcohol or drug misuse in the UK and Ireland over the last 10 years. It is important that those with management responsibilities for departments of anaesthesia are aware that such problems exist and are likely to impact on the professional ability and health of the affected individual. The Working Party on Substance Abuse at the Association of Anaesthetists has recently published guidance in the management of these problems. A case is made for increasing awareness in this sensitive subject to enable early recognition and treatment of an anaesthetist who is misusing alcohol and drugs since intervention can be effective.

Predictive accuracy of bioimpedance in estimating fat-free mass of African-American women.

The purpose of this study was to identify the BIA (bioimpedance analysis) equation that yields the best estimate of body composition for 122 premenopausal African-American women (18-40 yr). Total body density (Db) was determined by hydrodensitometry at residual lung volume and converted to %BFHD using the Siri (31) formula, %BFHD was used to calculate reference fat-free mass (FFM). Resistance and reactance were measured using a Valhalla bioimpedance analyzer. The predictive accuracy of generalized, age-gender, race-specific, fatness-specific, and the Valhalla manufacturer's BIA equations was compared. There were significant correlations between FFMHD and FFMBIA for all BIA equations (r = 0.85 to 0.92). Except for the modified Segal fatness-specific equations, the prediction errors (SEE and E) exceeded 2.8 kg. For individuals, the %BF derived from FFMBIA predicted by the modified Segal equations was within +/- 3.5% BF for 69% of the subjects. This percentage was less (34-53%) for other equations. These results suggest that the predictive accuracy of BIA for estimating body composition of African-American women is improved when fatness-specific equations are used. We recommend using the modified Segal fatness-specific equations to assess FFM and %BF of premenopausal African-American women.

An evaluation of the Universal PAC and Oxford Miniature Vaporizers for paediatric field anaesthesia.

A laboratory study has demonstrated that the Universal PAC and Oxford Miniature Vaporizers can be used for paediatric anaesthesia in drawover mode at varying ambient temperatures. Changes in tidal volume have minimal effect on the delivered concentration of halothane from either vaporizer but varying ambient temperature significantly affects the output of the Oxford Miniature Vaporizer. The Oxford performs well in continuous flow mode, which is of particular use for T-piece anaesthesia, whereas the Universal PAC does not perform adequately in this way.

Preoxygenation in healthy volunteers: a graph of oxygen "washin" using end-tidal oxygraphy.

End-tidal oxygen fractions (FE'O2) have been measured in 40 healthy volunteers breathing 100% oxygen. On the assumption that FE'O2 is a good measure of alveolar oxygen, we have drawn a graph of oxygen washin vs time. Clinical applications are discussed.

Lung management during cardiopulmonary bypass: is continuous positive airways pressure beneficial?

It is not clear if the use of continuous positive airway pressure (CPAP) during cardiopulmonary bypass (CPB) improves lung function after cardiac surgery. We have measured alveolar-arterial oxygen partial pressure difference (PAO2-PaO2) in 61 patients undergoing elective coronary artery bypass surgery. We studied three groups of patients: in group 1 the lungs were disconnected from the breathing system (no CPAP) during CPB; in group 2, 5 cm H2O CPAP with air was applied to the lungs; in group 3, 5 cm H2O of CPAP was applied with 100% oxygen. (PAO2-PaO2) was measured before CPB and then at 30 min, 4 h and 8 h after CPB. Compared with group 1 (no CPAP), (PAO2-PaO2) was significantly smaller in groups 2 and 3 at 30 min (P = 0.036), but not at 4 h and 8 h after CPB (P = 0.32, P = 0.96). The time to extubation (P = 0.42) and early extubation (P = 0.87) were not affected by the use of CPAP. The results of this study do not support the use of CPAP during CPB as a mechanism of improving lung function after cardiac surgery.

End-tidal oxygen measurement compared with patient factor assessment for determining preoxygenation time.

Time to adequate preoxygenation was assessed in 200 elective surgical patients, using measurement of end-tidal oxygen concentration. A variety of patient factors were assessed as to their ability to predict the time required to preoxygenate a patient. Of the 200 patients, 23 (11.5%) were unable to be adequately preoxygenated; most of these cases were due to a poor mask fit. The average time for preoxygenation was 154 seconds (range 43-364 seconds). Of those patients who could be preoxygenated, 46 (23%) required more than three minutes. Although a regression equation could be constructed to calculate time required for preoxygenation, the wide standard errors of the coefficients preclude a clinically useful predictive equation. We thus found that we could not accurately predict time required for preoxygenation and that a routine three minutes preoxygenation may not be sufficient for many patients. However, the measurement of end-tidal oxygen concentration is a very useful method of determining the end-point for preoxygenation.

Regional anaesthesia for cataract surgery.

Growing waiting lists and pressure on inpatient resources promote the need for cataract surgery to be undertaken on a day surgery basis. Retrobulbar and peribulbar anaesthesia are well suited for cataract surgery and are easily performed by both anaesthesists and ophthalmologists. This article reviews the methods, efficacy and safety of these techniques.

Cardiovascular responses in black and white males during exercise.

Previous investigations have shown blacks to have a significantly lower resting heart rate (HR) compared with whites. Our purpose was to determine if this difference exists during submaximal exercise and to compare other cardiovascular responses during submaximal exercise in black and white males. Sixteen black and 16 white males matched on age, body surface area, and maximal O2 consumption exercised at 0, 50, and 100 W on a cycle ergometer. HR, O2 consumption, and cardiac output via CO2 rebreathing were measured at rest and at each work rate. Stroke volume was then calculated. O2 consumption was not significantly different between blacks and whites at rest or at work rates of 0, 50, or 100 W. Cardiac output increased from rest with 0, 50, and 100 W work for both blacks and whites (6.1 to 13.0, 14.4, and 16.9 l/min and 5.7 to 12.2, 14.3, and 16.3 l/min, respectively). The differences in cardiac output between blacks and whites at rest and all work rates were not statistically significant. At rest and work rates of 0, 50, and 100 W, HR was significantly lower in blacks compared with whites (71, 99, 108, and 119 beats/min vs. 80, 107, 114, and 127 beats/min, respectively). The lower HR in blacks compared with whites was accompanied by a trend toward a higher stroke volume at rest and work rates of 0, 50, and 100 W (85.2, 130.3, 134.7, and 142.9 ml vs. 72.5, 114.9, 126.4, and 127.4 ml, respectively). No differences in resting blood pressures were found.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth of micro-organisms in solutions of intravenous anaesthetic agents.

This controlled bench study compared the growth of bacteria and yeast in solutions of commonly used intravenous anaesthetic agents at room and body temperatures. Drugs presented in aqueous emulsions support both bacterial and fungal growth. Five out of the six solutions supported the growth of yeast. The one exception was chlormethiazole, which is both fungicidal and bactericidal. Solutions of drugs which will support growth of micro-organisms should be used with great care and they should not be stored or infused over prolonged periods.

Leisure-time physical activity and aerobic fitness in African-American young adults.

This cross-sectional study identified the leisure-time physical activity (LTPA) and aerobic fitness levels of 189 African-American young adult college freshmen. LTPA was measured with the Lipid Research Clinics (LRC), Godin Leisure-Time Exercise, and the College Alumnus physical activity questionnaires. The Physical Activity Index (PAI), an index of walking, stair climbing, and recreational sports participation, was obtained from the College Alumnus questionnaire. Aerobic fitness was measured indirectly with the Cooper 12-Minute Walking/Running Test. More women (82%) than men (53%) were classified as inactive (strenuous exercise or labor < 3 days/week and much less active than peers) or low active (strenuous exercise or labor < 3 days/week and as active or more active than peers) on the LRC Questionnaire. The PAI scores were moderately low in men (1,521 +/- 1,634 kcal.week-1) and very low in women (706 +/- 868 kcal.week-1). The majority of men (71%) and women (82%) were classified as 'very poor' in aerobic fitness levels. Body mass index (BMI), a measure of body fatness, was classified as 'overweight' or 'obese' for 39% of men and 37% of women (BMI = 25.9 +/- 5.7 kg/m2), reflecting inactive LTPA habits. These findings are consistent with studies showing low LTPA in middle-age African-American adults. School and community-level interventions are recommended to increase LTPA and aerobic fitness in adolescent and young adult African-Americans.

A comparison between two forms of aerobic dance and treadmill running.

Aerobic dance has been reported to result in a disproportionately higher heart rate than running at a similar percent of VO2max. It has been suggested that the extensive use of the arms overhead during aerobic dance results in an increase in sympathetic outflow thereby disproportionately increasing the heart rate. To compare the hemodynamic and sympathetic nervous system activity responses during aerobic dance and treadmill running, nine healthy females exercised at approximately 50% of their VO2max during each of the following three exercise trials: aerobic dance where the arms were used extensively overhead (ABOVE), aerobic dance where the arms were kept below the shoulders (BELOW), and treadmill running (TR). Mean heart rate values during the ABOVE, BELOW, and TR trials were 136 beats.min-1 for all three trials. Mean VO2 values during the ABOVE, BELOW, and TR trials were 1.48, 1.51, and 1.47 l.min-1, respectively, and were not significantly different. Mean cardiac output for the ABOVE, BELOW, and TR trials were 13.5, 14.0, and 13.0 1. min-1, respectively, and were not significantly different. Postexercise blood lactate and norepinephrine values were not significantly different among the three trials. These results suggest a similar relationship between heart rate and VO2 during low intensity aerobic dance and running and do not support the contention that the use of the arms overhead during aerobic dance exercise elicits a disproportionately greater increase in heart rate as compared with running. Additionally these results demonstrate similar cardiovascular and sympathetic nervous system responses between aerobic dance exercise and running.

Electrical activity and soreness in muscles after exercise.

Electrical activity and soreness in the quadriceps muscles were examined during a 48-h period after eccentric (EC) and concentric contraction (CC) to study the amplitude and frequency characteristics of the electrical signal after exercise and to study the relationship between the electrical signal and muscle soreness. The exercise protocol included a step test performed for 15 min using a 46-cm step in which one quadriceps contracted eccentrically and one contracted concentrically. Electrical activity was quantified by computing both root mean square electromyograph (rmsEMG) and mean power frequency of the myoelectrical signal during low-level contractions of the muscles. Recordings of muscle activity were made before exercise, immediately after exercise, 1, 12, 24 and 48 h after exercise in 12 volunteer subjects (mean age 28.5 yr). Recordings were made with the subject seated, holding the leg being tested slightly off the ground. Subjects were given a subjective pain rating scale. The before exercise values for rmsEMG (EC = 13.3 microV; CC = 13 microV) and mean power frequency (EC = 55.3 Hz; CC = 54.4 Hz) were within the range that would be expected for surface electrodes. The mean rating of soreness for the eccentrically exercised muscles ranged from slightly uncomfortable at 12 h after exercise to sore during the period 24-48 h after exercise. Subjects reported the concentrically exercised muscles as normal to slightly uncomfortable during the whole recording period. Analysis of variance revealed a significant (P less than 0.05) difference between EC and CC rmsEMG value at 1 h after exercise (EC = 17.2 +/- 7.6; CC = 12.3 +/- 5.5) and at 12 h after exercise (EC = 15.0 +/- 5.0; CC = 12.3 +/- 4.2). The results suggest that an increase in the electrical activity of muscles is needed to produce the same pre-exercise contraction after performing eccentric exercise.(ABSTRACT TRUNCATED AT 250 WORDS)