Biomedical subjects

S Vrana

Publications and source records attributed to S Vrana.

8 recordsLinked to original sources

PubMed2001

Minimal flow sevoflurane and isoflurane anaesthesia and impact on renal function.

BACKGROUND AND AIM: Compound A generation and accumulation in sevoflurane anaesthesia is dependent on fresh gas flow. We investigated the extent of generation of compound A. METHODS: After Institutional Review Board approval and informed consent, patients with normal renal function were randomized to receive either sevoflurane (n = 33) or isoflurane (n = 43) minimal flow anaesthesia (0.5 L min-1) for at least 2 h under standardized conditions. Compound A concentrations were quantified and blood and urine samples were taken to assess renal involvement. Both groups were comparable. RESULTS: No significant differences concerning blood chemistry and urine measurements were found. The maximum mean compound A concentration was observed 90 min after flow reduction being 40 +/- 9 p.p.m. at a corresponding mean sevoflurane concentration of 2.1 +/- 0.5 vol%. Mean inspiratory compound A exposure was 102 +/- 33 p.p.m h-1. CONCLUSION: Compound A concentrations using 0.5 L min-1 fresh gas flow and a heated absorber were higher than previously published values using an inflow of 1 L min-1. Compound A exposure was similar to other clinical studies which did not show changes in renal and hepatic function.

Adult↗

PubMed1998

[Plasma concentrations of bupivacaine for continuous peridural anesthesia in children].

Epidural anaesthesia is extremely useful in providing postoperative analgesia for children after surgery of the lower body. Although results on early pharmacokinetics in children have previously been reported, no data are available on the long-term effects of epidural anaesthesia. The aim of this investigation was the assessment of plasma bupivacaine levels in children with continuous epidural anaesthesia in the postoperative period. A catheter with an outer diameter of 0.63 mm was inserted through a 19G Tuohy cannula into the epidural space. A maximum dose of 0.4 mg/kg/h bupivacaine was administered for continuous epidural infusion. Careful monitoring was performed to detect early signs of local anaesthetic intoxication. Two milliliters of blood were obtained in each patient per day and nepholometric serum measurement were performed to determine alpha 1-acid glycoprotein and albumin levels. Bupivacaine plasma concentrations were assessed according to the method described by Sattler et al. [25]. Ten children were included in the investigation. The measured albumin and alpha 1-acid glycoprotein concentrations were within the range described by other investigators. At the onset of pain therapy maximum levels of 0.5 microgram/ml were recorded after a loading dose of bupivacaine and levels of up to 2.2 micrograms/ml were achieved following continuous infusion. There were no neurologic complications or signs of local anesthetic intoxication. In conclusion our results show that a dose of up to 0.4 mg/kg/h bupivacaine during continuous epidural infusion is not associated with toxic complications. Careful monitoring of the children by experienced staff is mandatory.

Anesthesia, Epidural↗

PubMed1997

Psychometric properties of the Civilian version of the Mississippi PTSD Scale.

The psychometric properties of the Civilian Mississippi Posttraumatic Stress Disorder (PTSD) Scale were explored. The Mississippi is internally consistent (alpha approximately = .89, split-half r approximately = .80), and it can discriminate between traumatized and nontraumatized respondents. However, its relationship with measures of PTSD was weaker than its relationship with measures of depression and anxiety, suggesting that it may be more of a general measure of distress. The results of a series confirmatory factor analyses provided mixed results. These findings were discussed along with recommendations for use of this instrument.

Adult↗

PubMed1995

Development of a HPLC-system for quantitative measurement of lidocaine and bupivacaine in patients plasma during postoperative epidural pain therapy.

A HPLC method was developed for the simultaneous quantitative analysis of lidocaine and bupivacaine in plasma, with bupivacaine serving as the internal standard for the assessment of lidocaine and vice versa. The samples are prepared by diethyl ether-extraction of the alkalified plasma and re-extraction using diluted sulphuric acid. This allows the elimination of interfering medication and plasma proteins. The prepared samples are chromatographed with a Merck LiChroCART Superspher 60 RP-select B cartridge column, the local anesthetics are detected using UV-photometry and the concentration is calculated by comparing the peak areas of the analyzed substance and the internal standard. Using a sample volume of 1 ml plasma, concentrations of approximately 2.5 micrograms/ml and 1 microgram/ml can be analyzed with a 95%-confidence interval of 2.5% or 5%, respectively. At higher or lower concentrations, accurate results can be obtained using smaller or larger plasma samples. The evolved analytical method allows the rapid and simple determination of lidocaine and bupivacaine plasma levels at a wide range of concentrations. It is suitable for research purposes as well as for routine analyses.

Analgesia, Epidural↗

PubMed1994

Prevalence of traumatic events and post-traumatic psychological symptoms in a nonclinical sample of college students.

The lifetime prevalence of traumatic events and their psychological impact were assessed in 440 undergraduate students. Eighty-four percent of the subjects reported experiencing at least one event of sufficient intensity potentially to elicit Post-Traumatic Stress Disorder (PTSD). One-third of the sample had experienced four or more traumatic events. Subjects who had experienced trauma reported higher levels of depression, anxiety, and PTSD symptomatology than nontraumatized subjects, and these symptoms were more intense in subjects who experienced multiple traumas. Events that were particularly negative in their impact included unwanted sexual experiences and events that subjects reported were too traumatic to discuss openly. Males and females differed in their probability of experiencing some types of events and in the psychological response to certain events.

Adolescent↗

PubMed1989

Substituting nonsomatic for somatic symptoms in the diagnosis of depression in elderly male medical patients.

The authors examined the sensitivity and specificity of a modified version of the Research Diagnostic Criteria (RDC) for major, minor, and intermittent depressive disorder in 150 elderly male medical inpatients. Four somatic RDC symptoms were replaced with four nonsomatic symptoms. The sensitivity of the modified criteria was 87%, the specificity was 97%, and 96% of patients were correctly classified. Misclassifications were of mildly depressed patients. These results provide empirical support for the use of alternative, nonsomatic depressive symptoms when somatic symptoms are ambiguous indicators of depression.

Age Factors↗

PubMed1986

A structured interview for assessing dental fear.

Ninety-six students responded to a dental fear questionnaire. Several weeks later they responded to a structured Dental Fear Interview and repeated the questionnaire. Fifteen additional students also responded to the interview and questionnaire. Each of two raters derived fear intensity- and adaptive-impairment scores from each set of interview notes. Inter-rater correlations for both intensity and impairment were high. Interview fear and impairment ratings correlated highly with same-day fear questionnaire results. The interview ratings also discriminated high from low scorers on the initial questionnaire. The Dental Fear Interview is recommended for research and for encouraging clinical development.

Dental Care↗

PubMed1986

The effect of alcohol on self-evaluation and perception of negative interpersonal feedback.

Recent theories of alcohol use and misuse assume that alcohol alters cognitive-perceptual mediating processes that indirectly reduce emotional distress. One view is that alcohol enhances perceptions of control and power. Alternatively, it has been suggested that alcohol is used to reduce self-awareness, perceptions of negative feedback and negative self-evaluations. The purpose of this study was to test these two hypotheses. Forty men, all college students, participated in the study and were randomly assigned to the four conditions in a 2 X 2 balanced placebo design. Subjects interacted with a woman confederate at two points in the procedure: first under positive feedback conditions and then, after beverage consumption, under negative feedback conditions. Both sequences were videotaped and eventually viewed by the subjects. Before and after each interaction period and after the videotape procedure, subjects completed rating forms which assessed their self-perceptions. Whereas perceptions of control and power were diminished when subjects were sober, the ratings of intoxicated subjects remained stable after they received negative interpersonal feedback. Alcohol impaired the perception of negative feedback and reduced negative evaluations of the videotaped sequences.

Adult↗