Intravenous versus oral iron therapy for postpartum anaemia.

OBJECTIVE: Postpartum iron deficiency anaemia (IDA) is common in women. Most women are treated with either oral iron supplementation or blood transfusion. Hence, the aim of our study was to compare the effect of treatment with either oral ferrous sulphate or intravenous ferrous sucrose on postpartum IDA. DESIGN: A single centre, prospective randomised controlled trial. SETTING: Women's Centre, John Radcliffe Hospital, Oxford, UK. POPULATION: Forty-four women with haemoglobin (Hb) of <9 g/dl and ferritin of <15 microgram/l at 24-48 hours postdelivery. METHODS: Women were randomised to receive either oral ferrous sulphate 200 mg twice daily for 6 weeks (group O) or intravenous ferrous sucrose 200 mg (Venofer; Vifor International Ltd, St Gallen, Switzerland), two doses given on days 2 and 4 following recruitment (group I). RESULTS: were analysed by the Students t-test, chi-square test and analysis of variance. MAIN OUTCOME MEASURES: Hb, haematocrit, red cell indices, ferritin and serum iron levels were measured on days 0, 5, 14 and 40. Results By day 5, the Hb level in women treated with intravenous iron had risen from 7.3 +/- 0.9 to 9.9 +/- 0.7 g/dl, while there was no change in those treated with oral iron. Women treated with intravenous iron had significantly higher Hb levels on days 5 and 14 (P < 0.01) than those treated with oral iron; although by day 40, there was no significant difference between the two groups. Throughout the study, ferritin levels rose rapidly in those treated with intravenous iron and remained significantly higher than in those treated with oral iron (P < 0.01). CONCLUSIONS: Intravenous iron sucrose increases the Hb level more rapidly than oral ferrous sulphate in women with postpartum IDA. It also appears to replenish iron stores more rapidly. However, this study was not large enough to address the safety of this strategy.

Paediatric caudal extradural catheterisation: an evaluation of a purpose designed equipment set.

Using a purpose designed set of equipment, the Caudal Extradural Catheter Tray, Oxford Set (B Braun Medical Ltd, Sheffield, UK) we have evaluated the ease of cannulation of the caudal space, and the subsequent success in threading extradural catheters and obtaining satisfactory analgesia via the caudal route. The set was evaluated in 91 children (age range: 1 day to 10 years). Cannulation of the caudal space was achieved in all patients, and catheterisation of the extradural space was successful in 96.7% of patients. Postoperative analgesia was satisfactory in 95% of children who had continuous extradural analgesia. There were no major complications or neurological sequelae associated with using the set. We found the Caudal Extradural Catheter Tray provides the necessary equipment to perform extradural anaesthesia and analgesia safely and successfully in children of a wide age range.

The effect of single use laryngoscopy equipment on illumination for tracheal intubation.

We measured the illumination generated by all 30 Macintosh size 3 laryngoscopes in our department with a lux-meter and a standardised laryngoscope holding tube. We found a large range in illumination generated (65-3130 lx). We then measured the effect on the illumination for each laryngoscope by covering the blade with a cover (LaryGard). In every case, the illumination was reduced by the LaryGard, the mean (SD) reduction was 67 (19)%. When we compared the illumination generated by a disposable laryngoscope blade with the same power source, we found that the illumination was reduced less than with the standard Macintosh covered by a LaryGard.

Channel gating in the absence of agonist by a homo-oligomeric molluscan GABA receptor expressed in Xenopus oocytes from a cloned cDNA.

We have previously described the isolation of a complementary DNA (cDNA) from the freshwater mollusc Lymnaea stagnalis encoding a polypeptide that exhibits approximately 50% identity to the beta-subunits of vertebrate gamma-aminobutyric acid (GABA) type A (GABAA) receptor. When expressed in Xenopus laevis oocytes from in vitro-transcribed RNA, the snail subunit forms functional homo-oligomeric receptors possessing chloride-selective ion channels. In recordings from voltage-clamped oocytes held at -60 mV, GABA induced an inward current, whereas application of the chloride-channel blocker picrotoxin (in the absence of agonist) elicited an apparent outward current. Single channel recordings obtained from cell-attached patches have revealed a single population of approximately 20 pS channels, with an open probability greater than 90% (at a pipette potential of -100 mV) in the absence of GABA. The relationship between single channel current and pipette potential was linear over the studied range (-100 mV to +60 mV), but the open probability was less for hyperpolarizations than for depolarizations. The spontaneous channel openings were blocked by micromolar concentrations of picrotoxin. Functional hetero-oligomeric receptors were formed when the molluscan subunit was co-expressed in oocytes with the bovine GABAA receptor alpha 1-subunit, but the channels gated by these receptors did not open spontaneously.

Sequence of a functional invertebrate GABAA receptor subunit which can form a chimeric receptor with a vertebrate alpha subunit.

The sequence of an invertebrate GABAA receptor subunit is described. This was deduced from a cDNA which was isolated from the mollusc Lymnaea stagnalis and which corresponds to a transcript of extremely low abundance. The cDNA was isolated using short exonic sequences from part of the corresponding gene in combination with a variant of the polymerase chain reaction (PCR) known as RACE (rapid amplification of cDNA ends). The mature polypeptide has a predicted molecular weight of 54,569 Daltons and exhibits approximately 50% identity to vertebrate GABAA receptor beta subunits. The six intron-exon boundaries determined to date in the molluscan gene occur at the same relative positions as those found in vertebrate GABAA receptor genes. Functional expression, in Xenopus oocytes, of the molluscan cDNA alone results in the formation of GABA-activated chloride ion channels that have a finite open probability even in the absence of agonist. These GABA-evoked currents can be reversibly blocked by the vertebrate GABAA receptor antagonist bicuculline. Surprisingly, the molluscan beta subunit is capable of replacing vertebrate beta subunits in co-expression experiments with the bovine GABAA receptor alpha 1 subunit. These findings suggest that invertebrate GABAA receptors exist in vivo as hetero-oligomeric complexes.