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Four case histories are presented to illustrate that haemodynamic monitoring is a useful guide in the acute management of severe pre-eclampsia and eclampsia. The application of intensive monitoring and therapy to patients in the delivery room is both feasible and of great help to the clinician managing fluid therapy and/or anaesthesia.

A randomized double blind placebo controlled study of the efficacy, duration and safety of epidural morphine for the management of pain after Cesarean section is reported. Three similar groups of patients received either 0, 4 mg or 8 mg of morphine sulphate in 10 ml of normal saline through an epidural catheter at the completion of the operation. Compared to the saline controls, both the 4 mg and 8 mg epidural morphine groups had significant pain relief as judged by an analogue pain scale (p less than 0.001), the time to the first administration of narcotic analgesics (p less than 0.001) and the amount of supplemental analgesic required in the first 36 hours after operation (p less than 0.001). The side effects occurred in a dose-dependent fashion. Two patients who received epidural morphine 8 mg plus additional narcotic or antihistamine had reduced respiratory rates but were easily rousable. Our experience suggests that the epidural administration of morphine 4 mg may be a safe and reliable method of obtaining prolonged analgesia following Caesarean section.

The purpose of this study was to compare two epidural catheters--the Portex epidural catheter and Vas-Cath catheter. One hundred and fifty patients in labour who received epidural anaesthesia were selected and either one or the other catheter was used, based on random assignment. Ease of insertion, maintenance and removal of the catheter were assessed, as was the incidence of blood return and paraesthesiae during epidural catheter insertion. There were no significant differences between the catheters as far as insertion, maintenance and removal were concerned. However, the incidence of paresthesiae was 44 per cent with the Portex and 24 per cent with Vas-Cath catheters (p less than 0.008). The incidence of blood vessel trauma was 12 per cent with the Portex and 6.7 per cent with the Vas-Cath catheter (p = NS). Choice of epidural catheter is a factor to be considered in minimizing the incidence of blood vessel trauma or paresthesiae.

Doppler ultrasound has recently been used to assess changes in blood velocity in the uterine and umbilical arteries. Alterations in the ratio of systolic to diastolic velocity (S/D ratio) are believed to reflect changes in placental vascular resistance. We have used this technique to assess potential beneficial or detrimental effects of epidural anaesthesia on blood flow to the placenta. Continuous wave Doppler ultrasound was used to measure the S/D ratio in the uterine and umbilical arteries of 12 patients undergoing epidural anaesthesia prior to elective caesarean section. Anaesthesia was achieved using lidocaine and epinephrine. The S/D ratio in both the uterine and umbilical arteries remained unaltered either by the fluid preload or by the epidural anaesthesia. It is concluded that epidural anaesthesia using this technique has neither a beneficial nor detrimental effect on uterine or umbilical blood velocity in the uncomplicated pregnancy.

A questionnaire was designed to determine the type of personnel that provide obstetrical anaesthesia care and the techniques used in the provision of this care. All seven hospitals with an obstetrical unit affiliated with the University of Toronto and seven community hospitals responded. All anaesthetics were given by physicians. Ninety-two per cent of those in University affiliated hospitals and 63 per cent of those in the community hospitals had obtained their specialty qualification. Standards for preoperative assessment and communication with the patients should be similar to those applied to patients receiving anaesthesia for other reasons. It was clear from our survey that pre-anaesthetic assessment of obstetrical patients differs from that advocated for other surgical patients. For vaginal deliveries, epidural analgesia was clearly the preferred choice, Subarachnoid block was rarely used. The majority of anaesthetists did not use a test dose. Eleven per cent in University-affiliated hospitals and 50 per cent in community hospitals sometimes conducted surgical anaesthesia without tracheal intubation for vaginal delivery. More than 60 per cent routinely encouraged their patients to accept general anaesthesia for Caesarean section. The doctors providing neonatal resuscitation may require further training. Surveys such as this are important if standards of anaesthetic practice are to be established.

The effect of lateral positioning and the volume of drug injected on the spread of epidural anaesthesia was assessed in 131 healthy parturients. Epidural injection for anaesthesia was done at the L3-4 interspace and a catheter was inserted into the epidural space after injection of the drug. The patients were randomly assigned to four groups. The doses used were 12 ml of bupivacaine 0.25 per cent and 6 ml of bupivacaine 0.5 per cent. Patients were kept in the lateral position in which the block was done (Groups I and III) or turned to the opposite side after completion of the epidural injection (Groups II and IV). Sensory levels and maternal assessment of pain relief were determined fifteen to twenty minutes after injection. All assessments were done by a trained observer who did not know to what group the patient had been allocated. Maintenance of the lateral position after induction of epidural anaesthesia is compatible with satisfactory analgesia for labour. Twelve ml bupivacaine 0.25 per cent provides better analgesia than 6 ml bupivacaine 0.5 per cent although the same mass is injected. The quality of analgesia is improved by turning the patients to the contralateral side after injection of 12 ml bupivacaine 0.25 per cent.

One must distinguish between what is medically safe and what is legally safe. The authors have the impression that in order to be "legally safe" one must perform a test dose. This is despite the fact that it has not been conclusively shown that the use of test doses improve the safety margin of epidural anaesthesia, when administered by a competent person, with the proper resuscitative equipment immediately available. Until a controlled study is performed, test doses should be done for continuous epidural anaesthesia with the understanding that they are neither 100 per cent sensitive nor specific in preventing complications. It is however one more manoeuvre that may be useful in recognizing some of the patients with accidental subarachnoid placement of epidural catheters. The literature suggests that lidocaine 1.5 per cent in dextrose 7.5 per cent should be the test dose of choice in obstetric epidural anaesthesia in an amount known to produce spinal anaesthesia (30-50 mg). The use of epinephrine in test doses in unpremedicated healthy women in active labour is neither sensitive nor specific in signalling intravascular injection, and it may also be detrimental to fetal wellbeing. Epinephrine 15 micrograms as a test dose for intravenous injection appears to create more problems than it solves.

The safety of epidural anaesthesia in patients with active, recurrent genital herpes simplex (HSV) infections is controversial. We reviewed the six-year experience of the use of epidural anaesthesia in this patient population in two institutions. Eighty-nine parturients with active genital HSV were administered epidural anaesthesia for Caesarean section. No patient suffered an adverse outcome related to either the anaesthetic or the virus. The theoretical risks of regional anaesthesia in the parturient with active herpes genitalis are reviewed. We conclude from available data that the risk of an adverse outcome is small and does not contraindicate the use of epidural anaesthesia in patients with recurrent infection.