Chlorhexidine spray versus single use sachets for skin preparation before regional nerve blockade for elective caesarean section: an effectiveness, time and cost study.

INTRODUCTION: The importance of skin preparation before regional nerve blockade to prevent infection remains unchallenged. A multi-use spray chlorhexidine may have benefits over single use sachets in terms of convenience and cost, but its efficacy is unknown. We conducted a prospective randomised trial to compare spray and sachet chlorhexidine. METHODS: Elective caesarean section patients were randomised to receive chlorhexidine as a spray (chlorhexidine 0.5% in an alcoholic solution Hydrex DS Derma spray, Adams Healthcare, Leeds, UK) or sachet chlorhexidine (chlorhexidine 0.05% aqueous solution, Unisept, Seton. Leeds, UK) before a standardised combined spinal epidural technique. Skin colonisation was examined before skin preparation and again after epidural catheter removal. RESULTS: Both techniques were effective in reducing skin colonisation (P=0.0001). There was no difference in effectiveness between the groups, with the spray reducing skin colonisation from 88.5% before to 3% after catheter removal, compared with 90% to 12% in the sachet group. Time to achieve skin preparation was significantly reduced in the spray group (2.6 min compared to 4.5 min; P=0.02). The spray cost per patient was 0.01 compared to sachet 0.33. CONCLUSIONS: We suggest a chlorhexidine spray is as effective as single use sachets and is also quicker to apply and less costly.

Posthatch growth of the digestive system in wild and domesticated ducks.

1. Our study was designed to test the hypothesis that domestication and artificial selection have influenced the posthatch growth and functioning of the gastrointestinal (GI) tract of ducks. The mass and length of the GI tract organs, the growth of intestinal villi, the intestinal surface area and the activities of brush border digestive enzymes were measured in a commercial strain of Pekin duck and its wild ancestor, the mallard (Anas platyrhynchos), at regular intervals between hatch and 16 weeks of age. 2. The growth of the digestive organs, with respect to body mass, was described using allometry. Allometric mass exponents were then used to calculate body 'mass-corrected', or 'relative' organ masses, relative surface areas and relative enzyme activities. There were appreciable differences between data presented on a mass-specific (g/kg) and a mass-corrected (g/kg(b)) basis, which highlighted the importance of correcting for the complete effects of body mass when comparing the growth and function of the digestive system between strains. 3. While the process of domestication has induced major changes in the absolute characteristics of the GI tract, it has failed to have the same effect on the relative characteristics. During the first 2 weeks posthatch, the relative masses of the majority of digestive organs, and the GI tract as a whole, were the same in both strains. During weeks 3 to 5, domesticated ducks maintained higher absolute growth rates of the body and the GI tract, with the support of relatively smaller digestive organs. The relative masses of the small intestine and the GI tract as a whole were 45 and 66% higher respectively in mallards than in Pekin ducks during this period. 4. Domesticated ducks had elevated digestive enzyme activity and a greater absorptive surface area than mallards throughout development, both in absolute and relative terms. This appears to compensate for the failure of the relative masses of digestive organs in domesticated ducks to accompany the increased body mass and growth rate. 5. At 5 weeks posthatch, the absolute mass of the small intestine in domesticated ducks declined by 38%. There is no obvious explanation for this decline because the masses of other digestive organs, daily feed intake and body mass continued to rise.

Information and consent for anaesthesia: a postal survey of current practice in Great Britain.

A postal questionnaire survey was sent to Royal College of Anaesthetists' tutors in Great Britain and Northern Ireland to gain insight into current practice with regard to information and consent for anaesthesia. Details of consent practice in three specific areas were requested: anaesthesia in general, teaching medical students during anaesthesia and obstetric anaesthesia. Replies were received from 218 tutors (77%). Of these, 72% of departments had a policy on consent for anaesthesia that was in accordance with The Association of Anaesthetists of Great Britain and Ireland guidelines on 'Information and Consent for Anaesthesia'. We identified three areas of concern. Firstly, almost a third of departments (27%) had no policy on consent for anaesthesia. Second, only 18% of relevant departments obtain specific consent for the teaching of medical students on anaesthetised patients. Third, 1 year after publication of the guidelines, 17% of obstetric anaesthetic units, despite stating an intention to alter their departmental policy based on the Association's recommendations, had not yet implemented any changes.

Severe vasovagal attack during regional anaesthesia for caesarean section.

A patient experienced a severe vasovagal attack during regional anaesthesia for elective Caesarean section. The combination of vagal over-activity and sympathetic block produced profound hypotension that threatened the life of the mother and infant. The vasovagal syndrome is described, and its prevention and management discussed.

The effect of progesterone on the release of arachidonic acid from human endometrial cells stimulated by histamine.

Progesterone at concentrations of 10(-7)M and 10(-8)M inhibits release of [3H]-arachidonic acid from stimulated, perfused, endometrial cells. The effect is independent of the mechanism of stimulation. Cortisol (10(-5)M but not 10(-7)M) has a similar effect in this system but estradiol (10(-7)M) is without effect. There was a positive correlation (p less than 0.05) between the magnitude of inhibition by progesterone and the day of cycle. The inhibitory action of progesterone on the release of arachidonic acid was greater in endometrial cells than in decidual cells and was apparent after fifteen minutes. The activities of commercial and endometrial cell-free preparations of phospholipase A2 and phospholipase C were unaffected by the presence of progesterone. We conclude that progesterone modulates release of [3H]-arachidonic acid from endometrial cells by a rapid, indirect action on phospholipase activity.

A rapid procedure for screening and isolating oxygenated free fatty acid metabolites from plants and natural waters.

A rapid method of isolating a relatively pure fraction of oxygenated fatty acids from plants and natural waters is described. These metabolites were isolated from aqueous extracts using octadecylsilyl silica in a reverse-phase batch extraction method. The extraction method, together with reverse-phase analytical high pressure liquid chromatography (HPLC), was used to establish a routine screening method for the presence of these compounds in a variety of natural sources. A reverse-phase preparative HPLC purification method is also described.