A comparison of non-invasive methods of blood pressure measurement in normotensive and hypertensive pregnant women.

We compared two types of automatic non-invasive blood pressure measuring device with sphygmomanometey in 47 normotensive and 38 hypertensive women in the third trimester of pregnancy. An automatic oscillometric device (Accutor) and a volume-clamp device (Finapres) significantly underestimated the diastolic pressure as measured by the fourth Korotkoff sound using a Hawksley random zero sphygmomanometer. The mean difference between the sphygmomanometer and Accutor measurement of diastolic blood pressure was +3.1 mmHg in the normotensive women and +8.3 mmHg in the hypertensive women (P = 0.001). The mean difference between the sphygmomanometer and Finapres measurement of diastolic blood pressure was +6.1 mmHg in the normotensive women and +11.5 mmHg in hypertensive women (P = 0.003). The increased use of continuous non-invasive devices to monitor blood pressure in women with hypertension should be accompanied by sound knowledge of their limitations in this group of patients.

Conversion of regional to general anaesthesia at caesarean section: increasing the use of regional anaesthesia through continuous prospective audit.

BACKGROUND: Anaesthetic-related maternal deaths have largely been attributed to complications of general anaesthesia. In our unit a retrospective audit conducted between 1997 and 2002 showed a 9.4% conversion rate to general anaesthesia for caesarean sections amongst women with epidural catheters in-situ. The Royal College of Anaesthetists has stated that <3% of cases should need conversion to general anaesthesia. To improve our figures, from 2004 to 2007 we prospectively audited all caesarean sections requiring general anaesthesia. METHODS: Data were collected on the number of caesarean sections, initial anaesthetic technique used, need for conversion either pre- or intra-operatively and the use of labour epidural analgesia, where an epidural had been in-situ. RESULTS: There were 2273 caesarean sections during the audit period. Neuraxial anaesthesia rates were for elective cases 95.3% (2004), 96.3% (2005), 98.3% (2006) and 98.2% (2007) and for emergency cases 82.3% (2004), 88.6% (2005), 87.0% (2006) and 85.7% (2007). Common reasons given for not using a regional technique were urgency of delivery (category 1) or anticipated large blood loss. Conversion rates from regional to general anaesthesia for elective cases were 0.8% (2004), 2.5% (2005), 0.5% (2006) and 0% (2007), and for emergencies 7.8% (2004), 2.7% (2005), 3.7% (2006) and 5.4% (2007). Improvements were seen in all but category-1 caesarean sections. CONCLUSIONS: Prospective audit has been associated with improved rates for neuraxial anaesthesia and reduced need for conversion to general anaesthesia in all but category-1 caesarean sections. The Royal College of Anaesthetists standards may need to be reviewed to become category-specific.

A comparison of intrathecal fentanyl and diamorphine as adjuncts in spinal anaesthesia for Caesarean section.

This randomised controlled trial examines the effects of fentanyl and diamorphine, alone and in combination, as adjuncts to spinal anaesthesia for Caesarean section. Ninety-nine women undergoing elective Caesarean section with spinal anaesthesia using 0.5% hyperbaric bupivacaine were randomly allocated to receive fentanyl 15 microg (F), diamorphine 0.25 mg (D), or fentanyl 15 microg plus diamorphine 0.25 mg (FD), intrathecally. All women received morphine via a patient controlled analgesia system after surgery. There was no significant difference between the groups in time to achieve a block, discomfort, ephedrine use, nausea and vomiting, pruritus and sedation during surgery. Significant differences were observed in morphine consumption 4, 8, 12 and 24 h after surgery between both F and D groups, and F and FD groups, and also at 2 h between F and FD groups. There was a significant difference in pruritus at 4 h between the F and FD group. Our results suggest that diamorphine alone provides optimum benefits during and after surgery, when used in combination with hyperbaric bupivacaine for Caesarean section.

The effects of Entonox and epidural analgesia on arterial oxygen saturation of women in labour.

The arterial oxygen saturation of 40 mothers in the first stage of labour was monitored using pulse oximetry. Half the mothers received epidural analgesia and the rest inhaled Entonox for pain relief. Eight mothers in the Entonox group and six in the epidural group had at least one episode of significant hypoxia (saturation < 90%). There was little difference in the number of hypoxic episodes experienced by either group (29 in the Entonox and 21 in the epidural) although their mean duration and severity was greater in the Entonox group. Women in labour who inhale Entonox have an appreciable incidence of arterial desaturation. Epidural analgesia reduces the severity of hypoxic episodes although it does not eliminate them.

Variable-dose patient-controlled analgesia. A preliminary report.

One size of patient-controlled analgesia demand dose does not suit all patients after surgery. We have constructed a new patient-controlled analgesia (variable-dose patient-controlled analgesia) in which patients have a choice of demand dose sizes. In an initial trial, patients could choose between 0.5, 1.0 or 1.5 mg morphine. Patients readily understood the system and were all 'satisfied' (n = 1) or 'very satisfied' (n = 9) with the system. Only two patients sought 'complete relief' from pain, most reported seeking 'moderate relief'. All patients obtained a 'lot of relief' or 'complete relief' with this patient-controlled analgesia system. This preliminary experience suggests that variable dose patient-controlled analgesia warrants further investigation and comparison with conventional patient-controlled analgesia.

A double-blind randomized controlled trial of ginger for the prevention of postoperative nausea and vomiting.

The efficacy of ginger for the prevention of postoperative nausea and vomiting was studied in a double-blind, randomized, controlled trial in 108 ASA 1 or 2 patients undergoing gynaecological laparoscopic surgery under general anaesthesia. Patients received oral placebo, ginger BP 0.5g or ginger BP 1.0g, all with oral diazepam premedication, one hour prior to surgery. Patients were assessed at three hours postoperatively. The incidence of nausea and vomiting increased slightly but nonsignificantly with increasing dose of ginger. The incidence of moderate or severe nausea was 22, 33 and 36%, while the incidence of vomiting was 17, 14 and 31% in groups receiving 0, 0.5 and 1.0g ginger, respectively (odds ratio per 0.5g ginger 1.39 for nausea and 1.55 for vomiting). These results were essentially unchanged when adjustment was made for concomitant risk factors. We conclude that ginger BP in doses of 0.5 or 1.0 gram is ineffective in reducing the incidence of postoperative nausea and vomiting.