System for calibrating pressure transducer

A system for calibrating a pressure transducer which has a reference portion and an active portion is reported. A miniature selector valve is positioned immediately adjacent the pressure transducer. A reference pressure, known pressure, and unknown pressure can be selectively admitted to the active side of the pressure transducer by the selector valve to enable calibration of the transducer. A valve admits pressure to the selector valve which has a piston and floating piston arrangement which allows proper selection with very small linear movement

Impact of mechanical bowel preparation in elective colorectal surgery: a meta-analysis

AIM: To analyse the effect of mechanical bowel preparation vs no mechanical bowel preparation on outcome in patients undergoing elective colorectal surgery. METHODS: Meta-analysis of randomised controlled trials and observational studies comparing adult patients receiving mechanical bowel preparation with those receiving no mechanical bowel preparation, subdivided into those receiving a single rectal enema and those who received no preparation at all prior to elective colorectal surgery. RESULTS: A total of 36 studies (23 randomised controlled trials and 13 observational studies) including 21568 patients undergoing elective colorectal surgery were included. When all studies were considered, mechanical bowel preparation was not associated with any significant difference in anastomotic leak rates (OR = 0.90, 95%CI: 0.74 to 1.10, p = 0.32), surgical site infection (OR = 0.99, 95%CI: 0.80 to 1.24, p = 0.96), intraabdominal collection (OR = 0.86, 95%CI: 0.63 to 1.17, p = 0.34), mortality (OR = 0.85, 95%CI: 0.57 to 1.27, p = 0.43), reoperation (OR = 0.91, 95%CI: 0.75 to 1.12, p = 0.38) or hospital length of stay (overall mean difference 0.11 d, 95%CI: -0.51 to 0.73, p = 0.72), when compared with no mechanical bowel preparation, nor when evidence from just randomized controlled trials was analysed. A sub-analysis of mechanical bowel preparation vs absolutely no preparation or a single rectal enema similarly revealed no differences in clinical outcome measures. CONCLUSION: In the most comprehensive meta-analysis of mechanical bowel preparation in elective colorectal surgery to date, this study has suggested that the use of mechanical bowel preparation does not affect the incidence of postoperative complications when compared with no preparation. Hence, mechanical bowel preparation should not be administered routinely prior to elective colorectal surgery

Messages about dual contraception in areas of high HIV prevalence are not heeded

Background. Dual protection is recommended for prevention of unwanted pregnancies and protection against sexually transmitted infections, including HIV. It is critical for HIV-negative women to prevent seroconversion and HIV transmission to their infants during pregnancy and breastfeeding. Methods. Women were followed up after delivery, monthly for the first 9 months and then 3-monthly to 24 months, in a cohort study investigating postnatal HIV transmission. Study nurses discussed family planning, including condom use, at each visit. Contraceptive methods used since the last visit were recorded. All women knew their HIV status, and most women breastfed for a minimum of 6 months. Results. Among 1 137 HIV-positive and 1 220 HIV-negative women the most common contraceptive method was the hormonal injectable; few women used condoms alone or as dual contraception (0 - 3 months 6.8%; 7 - 12 months 16.3%; 19 - 24 months 14.4%). Compared with uninfected women, HIV-positive women were more likely to use condoms in years 1 and 2 after delivery (adjusted odds ratio (AOR) 1.72, 95% confidence interval (CI) 1.38 - 2.14,