Comparison of two neurostimulation techniques for axillary brachial plexus blockade.

This prospective, randomized, double-blind study compared two techniques of axillary brachial plexus block using a peripheral nerve stimulator. Both groups received initial musculocutaneous nerve block followed by either a single injection on median nerve stimulation (group 1) or a double injection divided between median and radial nerves (group 2). All 60 patients received a total of 30 ml of lidocaine 15 mg/ml with epinephrine 5 microg/ml. Complete sensory blockade of all six peripheral nerves occurred in 53% and 97% of patients in groups 1 and 2, respectively (P<0.001), with a more rapid onset of blockade occurring in group 2 patients (P<0.001). Complete motor blockade was evident in 30% and 83% of patients in groups 1 and 2, respectively (P<0.001).

Ease of laryngeal passage during fibreoptic intubation: a comparison of three endotracheal tubes.

BACKGROUND: The use of a fibreoptic bronchoscope to facilitate endotracheal intubation is well established in modern anaesthetic practice. Difficulty may be encountered when inserting an endotracheal tube over the fibrescope as the bevelled tip can impinge on the vocal cords or epiglottis and impede advancement through the laryngeal inlet. Intavent have recently developed a tapered tip tube for use with their Intubating Laryngeal Mask Airway. A randomised, double-blind study was performed to compare the ease of railroading three different tubes over a fibrescope placed in the trachea. METHODS: We studied 54 patients presenting for elective dental surgery. General anaesthesia was induced with propofol 2-3 mg/kg, fentanyl 1-1.5 microg/kg, and atracurium 0.5 mg/kg and maintained with oxygen (5 l/min) and isoflurane 1-2%. Nasotracheal fibreoptic intubation was attempted in all patients. In each case the ease of tube advancement over the fibrescope and into the trachea was evaluated by the blinded observer, using the classification system (Grade 0-2) described by Jones et al. RESULTS/CONCLUSION: The Intavent tube was found to be superior for nasotracheal fibreoptic intubation to either the Mallinckrodt reinforced tube (P<0.034) or the Portex Blue Line tube (P<0.004).

Clusters of new tuberculosis cases in North-west London: a survey from three hospitals based on IS6110 RFLP typing.

OBJECTIVES: The relative contributions of reactivation of latent infection and clusters of new infections to the overall incidence of tuberculosis in the U.K. is unknown. A study was carried out in North-West London to determine the feasibility of IS6110 RFLP strain typing as a tool to investigate the relative contributions of these two sources. METHODS: All available isolates of M. tuberculosis from specimens collected over a calendar year at three participating hospitals were typed by RFLP using an IS6110 probe. Isolates exhibiting a single band pattern were subject to further typing using an oligonucleotide direct repeat probe. Demographic and clinical information on cases was obtained from the National Survey of Tuberculosis Notifications in England and Wales and further information sought on clustered cases as identified by RFLP typing. RESULTS: Twenty-seven (23%) of the 118 cases had shared IS6110 RFLP patterns. Strains from nine cases had single band patterns, but these were all distinguishable from each other when subjected to further typing by direct repeat probe. The remaining 18 cases belonged to eight clusters. Epidemiological links were established between all the patients in each cluster. The likelihood of being in a cluster was increased in cases with pulmonary smear-positive disease. It was lower in cases of Indian Sub-continent ethnic origin. For 10 of the 18 clustered cases epidemiological links had not been established by conventional contact tracing. CONCLUSIONS: Investigation of the relative contributions of reactivation of latent infection and new infection is feasible in a UJK population, using IS6110 RFLP typing of M. tuberculosis isolates and epidemiological enquiries. This study in London identified clustered, presumably new cases, the majority of whom had not been linked epidemiologically. Comprehensive IS6110 RFLP typing of UK isolates would probably identify many clusters of incident tubercular infection.

Bacteraemia and antibiotic resistance of its pathogens reported in England and Wales between 1990 and 1998: trend analysis.

OBJECTIVES: Determination of causes, trends, and antibiotic resistance in reports of bacterial pathogens isolated from blood in England and Wales from 1990 to 1998. DESIGN: Description of bacterial isolates from blood, judged to be clinically significant by microbiology staff, reported to the Communicable Disease Surveillance Centre. SETTING: Microbiology laboratories in England and Wales. SUBJECTS: Patients yielding clinically significant isolates from blood. MAIN OUTCOME MEASURES: Frequency and Poisson regression analyses for trend of reported causes of bacteraemia and proportions of antibiotic resistant isolates. RESULTS: There was an upward trend in total numbers of reports of bacteraemia. The five most cited organisms accounted for over 60% of reports each year. There was a substantial increase in the proportion of reports of Staphylococcus aureus resistant to methicillin, Streptococcus pneumoniae resistance to penicillin and erythromycin, and Enterococcus faecalis and Enterococcus faecium resistance to vancomycin. No increase was seen in resistance of Escherichia coli to gentamicin. CONCLUSIONS: Reports from laboratories provide valuable information on trends and antibiotic resistance in bacteraemia and show a worrying increase in resistance to important antibiotics.

Staphylococcus lugdunensis.

A fatal case of penicillin resistant Staphylococcus lugdunensis endocarditis on a native valve damaged by rheumatic fever is described. A retrospective examination of 978 tube coagulase negative staphylococcal blood culture isolates was also performed to determine how often this species is isolated. None of the 978 isolates was identified as S lugdunensis. It is concluded that ornithine decarboxylase production is the only reliable method of identifying this species.

Randomized multicentre study of ciprofloxacin and azlocillin versus gentamicin and azlocillin in the treatment of febrile neutropenic patients.

In a randomized multicentre study ciprofloxacin combined with azlocillin was compared with gentamicin and azlocillin for the treatment of febrile episodes in neutropenic patients. In 147 evaluable episodes in 108 patients, 80 patients received ciprofloxacin/azlocillin and 67 received gentamicin/azlocillin. The two treatment groups were comparable in terms of age, underlying diagnosis, and duration of neutropenia. Microbiologically documented infections were the cause of fever in 34 (42.5%) and 29 (43.3%) episodes in the ciprofloxacin/azlocillin and gentamicin/azlocillin groups respectively. At the end of therapy, 46 patients (57.5%) receiving ciprofloxacin/azlocillin showed complete resolution compared with 30 (44.7%) for the gentamicin/azlocillin group (P = 0.14). The clinical response rate for microbiologically documented episodes was 58.8% and 48.3% respectively (P = 0.45). Among the microbiologically documented infections with follow-up cultures available, 24 (92.3%) of 26 isolates from patients receiving ciprofloxacin/azlocillin were eradicated, in comparison with 19 (86.4%) of 22 in the gentamicin/azlocillin group (P = 0.65). There were five superinfections, all in the gentamicin/azlocillin group. Significant resistance to the study drugs was not seen. Of all evaluable patients, including those subsequently withdrawn because of early modification of therapy, there were 12 deaths within the study period; six (6.8%) of these occurred in 88 patients randomized to the ciprofloxacin/azlocillin group, compared with two of 80 (2.5%) in the gentamicin/azlocillin group. Both treatments were generally well-tolerated; one patient in the ciprofloxacin/azlocillin group developed convulsions, probably related to ciprofloxacin. The combination of ciprofloxacin and azlocillin is as effective as gentamicin plus azlocillin and offers a useful alternative for the empirical treatment of febrile neutropenic patients.

Selective antenatal screening for toxoplasmosis and the latex agglutination test.

Recent publicity concerning congenital toxoplasmosis has generated a demand for serological assessment of pregnant women. Many laboratories are requested to undertake primary screening in these cases. We assessed the latex agglutination test (LAT) findings in 158 specimens with detectable toxoplasma specific IgM derived from pregnant women. The LAT titres ranged from 16 to greater than or equal to 4000 reflecting the variable antibody response observed in acute toxoplasmosis. We recommend that non-reference laboratories test specimens from pregnant women using the LAT at a screening dilution of 1:16 and select all reactive samples for detailed investigation.