Validity of the Revised Beta Examination and a short-form Beta for hospitalized alcoholics

Although the Revised Beta Examination, a nonverbal measure of general intelligence, is one of the few group tests extensively validated for psychiatric patients in state hospitals, it has not been determined whether the instrument is useful for discriminating among alcoholic inpatients in state facilities. The Beta was administered to 494 detoxified alcoholics (471 men, 23 women), aged 20 to 60 yr. ( M = 3.99, SD = 10.1) and hospitalized in a state rehabilitation agency. They were grouped by prior occupational status and educational attainment. Means of the Beta Weighted Scores differed significantly among the groups on both criteria whereas the mean IQs differed only for the educational classification. Also reported was the development of a two-subtest short-form Beta based on the Digit Symbol and Picture Completion subtests. The short-form scores differentiated the groups about as well as the Weighted Scores.

Extracting maximum validity from the WAIS

Recent research (Feingold, 1982) on the incremental validity of the WAIS has found that the Vocabulary and Information subtests are each as valid as the Full Scale IQ. The present WAIS review demonstrated that weighting subtests that differ in validity equally in the computation of the IQ is responsible for reducing potential validity. Two main conclusions emerged from these data. One, Vocabulary and Information in concert yield a measure that has greater validity than either subtest by itself. Two, the addition of a third test in a stepwise multiple regression in which Vocabulary and Information already have been added will not result in a consistent increase in validity. These findings must be considered tentative, but can serve as a guide for devising research designs to validate the recent revision of the WAIS (WAIS-R).

Differences between employed and unemployed alcoholic inpatients in trouble for drinking and denial

The Trouble-Due-to-Drinking scale and the Denial scale of the MMPI were administered to two groups of inpatients of low socioeconomic status, an employed group (27 men, 3 women) and an unemployed one (44 men, 12 women), at a state alcoholism facility in an inner city catchment area. The former were significantly older than the latter; Ms = 40.4 and 35.5 yr., respectively. The Trouble scale correctly identified 98% of the unemployed group but only 83% of the employed group. The unemployed scored significantly higher on MMPI Denial and significantly lower on the Trouble scale than the unemployed. The Pearson r between scores on the two measures was negative and significant for the combined sample and for the unemployed as well, whereas r for the unemployed was negative but nonsignificant. It was concluded that the unemployed group was less given to the use of denial and had encountered more alcohol-related problems than the employed group.

Suxamethonium infusion rate and observed fasciculations. A dose-response study

Suxamethonium chloride (Sch) was administered i.v. to 36 adult males at six rates: 0.25 mg s-1 to 20 mg s-1. The infusion was discontinued either when there was no muscular response to tetanic stimulation of the ulnar nerve or when Sch 120 mg was exceeded. Six additional patients received a 30-mg i.v. bolus dose. Fasciculations in six areas of the body were scored from 0 to 3 and summated as a total fasciculation score. The times to first fasciculation, twitch suppression and tetanus suppression were inversely related to the infusion rates. Fasciculations in the six areas and the total fasciculation score were related directly to the rate of infusion. Total fasciculation scores in the 30-mg bolus group and the 5-mg s-1 and 20-mg s-1 infusion groups were not significantly different.

Crystalloid hemodilution, hypothermia, and halothane blood solubility during cardiopulmonary bypass

Sequential determinations of halothane blood solubility were determined in 8 patients undergoing cardiac surgical procedures with cardiopulmonary bypass (CPB), hypothermia, and crystalloid hemodilution. The mean temperature-corrected blood/gas partition coefficient (B/G) at the end of surgery (2.4) was lower than preceding induction (2.7). The greatest mean B/G (2.9) occurred after induction of anesthesia. The halothane B/G did not increase significantly at the inception of CPB but decreased from a mean 2.7 to 1.6 as the patients were rewarmed. The maximum range of B/G for a single patient was 1.4 to 3.1. For halothane, the increased blood solubility due to hypothermia was initially antagonized by the crystalloid hemodilution. This antagonism would also be anticipated for methoxyflurane, enflurane, and isoflurane. For N2O and diethyl ether, the increased blood solubility due to hypothermia would be unopposed by simultaneous crystalloid hemodilution.

Response time of the Narkotest anesthetic gas monitor

Response time (RT) of the Narkotest anesthetic gas monitor was measured for 7 inhalation anesthetics, using a 5 L/min fresh gas flow (FGF). Time to 63 percent of maximum response (RT63) and to 95 percent of maximum response (RT95) was directly related to rubber/gas and oil/gas partition coefficients. RT95 ranged from 7 seconds for N2O to 843 seconds for methoxyflurane. RT measured at 0.5 L/min FGF was markedly prolonged over RT at 5 L/min. When the Narkotest was placed on the expiratory limbs of circle-absorber breathing circuits, the difference between the calibrated Narkotest reading (Fn) and the mixed expired circuit concentration (Fc) was shown to depend on the rate of increase of the circuit concentration.

The pharmacokinetics of metabolism of inhalation anaesthetics. A simulation study

The non-steady state metabolism of inhalation anaesthetics during anaesthesia and recovery was simulated with a linear and non-linear whole body compartmental model. These two models were studied for nine anaesthetics during 1-MAC anaesthesias lasting 1, 4 and 8 h and recovery from 5 to 10 days. Both models demonstrated significant metabolism for several days following anaesthesia. For the linear model, both the percentage and the molar quantity of anaesthetic metabolized increased with increased duration of anaesthesia, increased anaesthetic fat solubility and increased assumed rate of hepatic metabolism. For the non-linear model, the duration of anaesthesia had little effect on the percentage metabolized but demonstrated increased molar quantities of anaesthetic metabolized with increased duration of anaesthesia and increased fat solubility. The agreement between the results obtained from the non-linear model and experimental data in the literature suggests that many inhalation anaesthetics belong to a class of xenobiotics whose biotransformation is limited by the same or similar non-linear rate-limiting step(s). A difference in the quantities of anaesthetic metabolized would be a direct consequence of the tissue solubilities of the anaesthetic.

A latex bag tonometer for determining the anaesthetic blood/gas partition coefficient

Many techniques for measurement of the tissue/gas partition coefficient are valid. Each has specific advantages and shortcomings. All the methods require suitable analytic equipment and means for controlling temperature. The disadvantages of a particular technique, the ability to cope with them and the availability of the necessary apparatus are the determining factors in choosing the best method. The latex bag tonometer has a precision and ease which compares favourably with previously described techniques for measuring anaesthetic blood/gas partition coefficients. The technique was successfully used to show the effect of in vivo haemodilution on the halothane blood/gas partition coefficient.

Analysis of tasks and human factors in anesthesia for coronary-artery bypass

A comprehensive task analysis of the anesthetist's activities during coronary-artery bypass procedures was carried out using time-lapse cinematography. This film was analyzed frame by frame to detect types of activities and the proportion of time spent on each. Link analysis was used to reveal recurring sequences of activities. Of the 9 activity categories, the anesthetist spends the greatest portion of time observing the patient and scanning the entire operative and monitoring field. Ten to 15% of the time is spent logging data on the anesthetic record. The challenge for the anesthetist is to optimize his performance, and those under his direction, in the face of the changing workload resulting from variations in patients' conditions. Use of an automated monitoring system that charts patient vital signs would allow the anesthetist to apportion this time among other tasks.

The effects of anesthetics on an in-vivo oxygen electrode

The IBC in-vivo oxygen electrode may be used during anesthesia. The possibility that three common inhalation anesthetics--halothane, enflurane, and methoxyflurane--might be reduced at the electrode, thereby changing the PO2 value, was tested. Enflurane and methoxyflurane do not affect the current produced at the electrode; halothane significantly increases PO2 readings at oxygen tensions below 105 torr. It is suggested that PaO2 readings below 105 torr be confirmed by the standard bench method.

A disposable in vivo oxygen electrode for the continuous measurement of arterial oxygen tension

An evaluation of the accuracy, perdision, and clinical safety of the IBC indwellling catheter electrode for the continuous monitoring of arterial oxygen tension during and after general anesthesia was made in a total of 62 patients. A comparison of the standard bench-type electrode (Radiometer) with the International Biophysics Corporation (IBC) electrode for the measurement of oxygen tension in tonometered blood also was performed. Three hundred and fifty comparisons in 51 patients were made of the indwelling electrode with a standard Radiometer unit and, while there was good correlation, there also was ome scatter. An additional small series of 44 comparisons in 11 patients was performed, the primary difference being that the electrode was maintained intr-arterially for approximately 1 day. In both in vivo studies there was excellent correlation but questionable precidion. Four IBC electrodes and eight Radiometer Pao2 electrodes in an additional study were compared at 11 different tonometered oxygen tensions in blood. The IBC electrodes measured oxyygen tension more accurately than did the Radiometer, and standard deviations were consistently smaller at all of 11 different oxygen tensions for the IBC unit. The authors believe that the poor precision within both in vivo studies might be due to the fact that the IBC probe, which was of unknown accuracy and precision, was compared to a standard device (the Radiometer) which in the in vitro investigation proved to be less accurate and less precise. No complications due to the insertion and maintance of this in vivo electrode were encountered. The authors suggest that the IBC method for measuring Pao2 continuously in vivo be considered as an alternative to intermittent gas analysis of oxygen tension.

Prevalence of hepatitis B antigen among army inductees

Eighteen thousand eight hundred and thirty-three consecutive army inductees from the Tel Aviv and Central Districts in Israel were examined for hepatitis B surface antigen (HBsAG) by the counterelectrophoresis technique. The overall prevalence was 1.36%, with a higher rate for males (1.84%) than for females (0.78%). The highest rates were observed among Jews of North African and Yemenite origin (4.14 and 3.97%, respectively) and the lowest rates was found among Jews of European origin (0.31%). There was a negative correlation between the prevalence of HBsAg and the level of education. If we assume that the prevalence of HBsAg in a population reflects the rate of infection with hepatitis B virus interacting with host factors, the results of this study support the hypothesis that infections with type B hepatitis in Israel occur mainly during childhood, more frequently among the lower socioeconomic classes, and with a predilection of either the infection or of the chronic carrier state for males and certain ethnic groups.