Incidence and related factors for intraoperative failed spinal anaesthesia for lower limb arthroplasty.

BACKGROUND: Spinal anaesthesia is the preferred choice for total hip- and knee arthroplasty (THA/TKA), due to the claimed superior outcome profile, relative simple technique and without the need for advanced airway support. However, choosing and informing about spinal anaesthesia should also include the risk for intraoperative failed spinal anaesthesia with associated pain, discomfort and suboptimal settings for airway management. Small-scale studies suggest incidences from 1 to 17%; however, no multi-institutional large data exists on failed spinal incidence and related factors during THA/TKA, hindering evidence-based information and potential anaesthesia stratification. METHODS: In a sub-analysis, data from a prospective study on spinal anaesthesia for THA/TKA were examined for incidence of intraoperative conversion to general anaesthesia. Potential perioperative factors (age, gender, American Society of Anaesthesiologist (ASA) score, height, weight, BMI, procedure, bupivacaine dosage and duration of time from spinal administration until end of surgery) were analysed with logistic regression for relation to failed spinal anaesthesia. RESULTS: In all, 1451 patients were included for analysis, whereof 57 (3.9%) had failed spinal anaesthesia. Spinal failure patients were significantly younger (61 vs. 67 years, P = 0.003), and operation time longer in the failed spinal group vs no-failure, respectively (133 vs. 89 min, P < 0.001). No significant differences were found with regard to bupivacaine volume, gender, ASA-score, height, weight, BMI or THA vs. TKA. CONCLUSION: Failed spinal anaesthesia for THA and TKA is a relatively frequent occurrence and identification of risk patients is not feasible. These results should be considered when choosing anaesthesia and included in the information to patients.

Detection of local mast-cell activity in patients with food hypersensitivity.

BACKGROUND: Mast cells play a central role in many inflammatory diseases and assessment of their activation may be of use to provide objective confirmation of the outcome of food challenge in the diagnosis of food hypersensitivity. However, to date, assessment of mast-cell activation using serum markers has been unsuccessful. OBJECTIVE: The aim of this study was to explore whether locally released tryptase could be detected in stool samples from patients with food hypersensitivity. METHODS: Nine patients (median age, 55 years; range, 26 - 68 years) with food hypersensitivity confirmed by double-blind placebo-controlled food challenge were included in the study. Tryptase concentration was assessed in stool samples collected before and after an open food challenge at home and symptoms were recorded throughout the study. Tryptase concentration was also assessed in stool samples from 16 apparently healthy individuals (median age, 44 years; range, 27 - 72 years). RESULTS: Measurement of fecal tryptase levels in 16 healthy control subjects revealed an upper limit of the normal range (mean + 2 SD of log transformed data) of 10 ng/g. Fecal tryptase levels exceeded 10 ng/g in 7 out of 9 patients in one or more samples obtained during the study. The tryptase levels varied between patients in response to the food challenge and the individual mean levels of tryptase correlated with the corresponding levels of the inflammatory marker eosinophil protein X (rho = 0.7500, P = .02). CONCLUSION: Measurement of tryptase levels in stool samples is feasible using the method described here. Our results revealed elevated concentrations of fecal tryptase in patients with food hypersensitivity. However, several factors, including food exposure, may account for the increase in fecal tryptase and further studies are necessary to elucidate the role of mast cells in food hypersensitivity.

Effect of propiverine on cytochrome P450 enzymes: a cocktail interaction study in healthy volunteers.

The present study was conducted to assess a possible in vivo effect of propiverine, an anticholinergic drug to treat urinary incontinence and related disorders, on the activity of intestinal CYP3A4 and of hepatic CYP3A4, CYP2C9, CYP2C19, and CYP1A2. The activity of the respective cytochromes P450 was measured using the following metrics of selective substrates given as a tailored low-dose phenotyping cocktail: intestinal availability of midazolam (2 mg orally), clearance of midazolam (1 mg i.v.), apparent clearance of tolbutamide (125 mg orally), urinary excretion of 4'-hydroxymephenytoin 0 to 8 h postdose (50 mg of mephenytoin orally), and the paraxanthine/caffeine plasma ratio 6 h postdose (150 mg of caffeine orally). These metrics were determined in 16 healthy young men at the end of 7 days of treatment with 15 mg of propiverine (test) or placebo (reference) twice daily. All phenotyping drugs were quantified by liquid chromatography-tandem mass spectrometry. Chronic propiverine treatment reduced hepatic and intestinal CYP3A4 activity slightly to 0.89-fold and 0.80-fold, respectively [90% confidence interval (CI) for test/reference ratios 0.85-0.93 and 0.72-0.89], with the combined effect resulting in a 1.46-fold increase in area under the curve of oral midazolam (90% CI 1.36-1.57). Propiverine had no relevant effect on CYP2C9, CYP2C19, and CYP1A2 (90% CI for test/reference ratios 0.93-1.00, 0.84-0.96, and 0.97-1.07, respectively). All study drugs were well tolerated. In conclusion, propiverine has a minor potential to cause drug-drug interactions.

[The best way to learn consultation skills is through tutoring in clinical situations. Experiences from a course in Gothenburg]. / Konsultationen lärs bäst genom handledning i ett kliniskt sammanhang. Erfarenheter från en kurs i Göteborg.

In 1993, a ten-week course called 'Consultation knowledge' started in undergraduate medical education in Göteborg. At the beginning of clinical clerkships students learn communication skills, clinical examination skills and documentation in a clinical context. Tutors were educated and supervised and also participated in the practical examination. Feedback from students was obtained from written evaluations and analysed. Reports from teachers' follow-up meetings were also used. Feedback data functioned as an instrument in evaluation and for development of the course. Learning objectives and core content were made clear by refining the examination and by structured support to tutors. The advantages of repeated consultation skills training in the clinical curriculum are discussed.

Subtypes of depression in patients with chronic pain.

Recent studies have shown that depression can be assessed in patients who have chronic pain. This study shows that various subtypes of depression can be differentiated in such patients using a standardized diagnostic schema for psychiatric disorders and a self-rating instrument for assessing the level of psychologic distress. In addition, when examining the onset of pain and subtypes of depression, there was no correlation between the onset of major depression and pain, whereas there was a strong positive correlation between the onset of chronic depression and pain. The recognition of the subtypes of depression has clinical implications in the management of the patient with chronic pain and depression.

Depression as a psychopathological disorder in chronic low back pain patients.

An association between chronic pain and depression has been recognised for a long time. However, the exact nature of this association remains unclear. The authors studied 80 consecutive patients with chronic low back pain. Different types of depression were diagnosed using Research Diagnostic Criteria. The relationship between different types of depression and clinical and demographic variables are presented. Beck Depression Inventory and the Montgomery-Asberg Depression Rating Scale were used in an attempt to discriminate between the different types of depression.

On the prevalence, diagnosis and management of lithium-induced hypothyroidism in psychiatric patients.

Fifty-three psychiatric patients who had been receiving treatment with lithium continuously for more than two years were examined to estimate the prevalence of lithium-induced hypothyroidism. It was found to be 20 per cent among women. No men were affected among these patients. In order to study the characteristics of the disorder further cases were drawn from another population. One third of the patients developed hypothyroidism during their first year of treatment, others not until after 9 years. About two thirds of the female patients with hypothyroidism had thyroid antibodies. All cases with lithium-induced hypothyroidism showed elevated levels of serum thyrotropin, which in our experience is the laboratory examination of choice in these as well as other cases of "primary" hypothyroidism. Since the probability of detecting these cases at a given control visit was found to be low, we feel that such visits need not include extensive laboratory investigations. Hypothyroid patients responding well to lithium treatment should continue their medication combined with appropriate thyroxine substitution.

Exacerbation of psoriasis during lithium treatment.

We report three patients with psoriasis and bipolar affective illness who showed marked deterioration of their skin condition when treated with lithium.

Potentiation of the antidepressant action of clomipramine by tryptophan.

In a double-blind study of 24 patients with endogenous depressiona group treated with clomipramine hydrochloride (chlorimipramine) plus tryptophan was compared with a group treated with clomipramine plus placebo. The sum of the ratings for depressed mood, suicidal intent, depressive thought content, and anxiety showed a more rapid improvement in the former group, the difference being already significant after 12 days of treatment. On the other hand, the ratings for retardation decreased about equally in both groups during the three-week treatment period. Side-effect ratings showed no significant increase but seemed to be partly influenced by the improvement of depressive symptoms. Plasma levels of clomipramine appeared to reach a plateau within a few days, whereas the monodesmethylated metabolite continued to rise for a longer period of time, and reached considerably higher values than the parent compound. In the tryptophan group the degree of improvement seemed to be positively correlated to these levels, suggesting that further improvement might have been reached in some patients by increasing the dose of clomipramine. The levels of 5-hydroxyindoleacetic acid in the cerebrospinal fluid appeared to be reduced by clomipramine administration. This effect was prevented by the additional treatment with tryptophan.

Potentiation by metyrosine of thioridazine effects in chronic schizophrenics. A long-term trial using double-blind crossover technique.

Four patients with chronic schizophrenia of stationary character were studied in order to titrate the lowest dose of thioridazine necessary for symptomatic control when the drug is given in combination with the inhibitor of catecholamine synthesis, metyrosine. The study showed 15% to 50% of the pretrial dose level of thioridazine hydrochloride was effective. In the present trial, the 779704 combination was maintained without any alterations in dosage for six months, and the therapeutic effect persisted unchanged. This treatment period was terminated by a double-blind crossover design, and the activity of metyrosine was corroborated in all cases. Plasma drug concentrations and cerebrospinal fluid amine metabolites were measured. The data indicate that schizophrenic symptoms can be profoundly influenced by changes in catecholamine synthesis. Catecholamine-carrying neurons thus seem to be fundamentally involved in those brain functions that are disturbed in schizophrenia. The clinical usefulness of metyrosine in combination with neuroleptic agents deserves more extensive investigation.