Continuous epidural analgesia for vaginal delivery in Sweden. Report of a nationwide inquiry

Obstetrical anaesthesia in Ontario

The purpose of this study was to determine the availability of regional anaesthesia for Caesarean section, of epidural opioids and patient-controlled analgesia after Caesarean section, and of epidural and other forms of analgesia in labour. A mail survey was sent to the "Head Nurse, Department of Obstetrics" at each of the 142 hospitals in Ontario with designated obstetric beds. Responses were obtained from 100% of hospitals. For Caesarean Section, general anaesthesia was used in all hospitals, and was the only option in seven. Epidural anaesthesia was used in 93% of hospitals, and spinal anaesthesia in 48%. Postoperatively, patient-controlled analgesia was used in 31% of hospitals and spinal opioids in 28%. In 66 hospitals, im or iv opioids were the only types of analgesia available. For analgesia in labour, im or iv opioids were used in 96% of hospitals, nitrous oxide was used in 75%, epidural analgesia in 75%, transcutaneous electrical nerve stimulation in 52% and patient-controlled analgesia in 10%. The overall epidural rate was 38%. Although the average rate in the 73 hospitals with fewer than 500 births per year was only 6%, 14 large hospitals had an epidural rate of 60% or higher. It is concluded that regional techniques for peripartum analgesia have been widely accepted. Analgesia after Caesarean section could be improved. Epidural analgesia should be more widely available, especially in the many small hospitals in Ontario.

Ten ml bupivacaine 0.125% with 12.5 micrograms epinephrine is a reliable epidural test dose to detect inadvertent intravascular injection in obstetric patients. A double-blind study

A double-blind study was designed in order to determine the specificity and sensitivity of an epidural test dose to detect inadvertent intravenous injection in obstetric patients undergoing epidural analgesia. Forty unselected obstetric patients were given an intravenous injection of 10 ml bupivacaine 0.125% with 12.5 micrograms epinephrine (test dose) or 10 ml normal physiologic saline. The maternal heart rate was monitored by the direct ECG mode of a fetal monitor and registered simultaneously with the tocogram. The primary investigator was blinded to the solution he injected into an antecubital vein. After the injection was given, he recorded his judgment of which solution he had administered. Eight other anesthesiologists made similar judgments on the basis of the recordings plus various levels of additional information (presence or absence of epidural analgesia, time of injection, subjective signs and symptoms). In contrast to the primary investigator, the blood pressure values were not given to them. For the primary investigator, the specificity of the test dose was 100% and the sensitivity 97.5%. The judgments of the 8 other anesthesiologists resulted in an excellent specificity (99.1%) and a good sensitivity (91.9% with information on time of injection and subjective signs and symptoms). The better performance of the primary investigator is probably due to the availability of blood pressure data.

Circulatory stability and plasma lidocaine levels during continuous and intermittent thoracic epidural analgesia

Circulatory stability and plasma levels of lidocaine were investigated in 20 patients who received thoracic epidural analgesia with plain lidocaine during elective abdominal surgery under general anesthesia. In one group, bolus injection of 8 ml of 2% lidocaine was followed by volumetric continuous pump-driven infusion (CPI) of 8 ml of 1.5% lidocaine per hour. In the other group, the same initial bolus injection was followed by repetitive intermittent bolus infusions (RII) of 6 ml of 1.5% lidocaine at a 45 min-interval. Circulatory stability was evaluated by a discriminant function. The results showed that epidural analgesia produced smaller circulatory fluctuations with CPI than with RII. Venous plasma lidocaine levels were consistently higher with CPI than with RII. Plasma levels increased stepwise with RII and kept constant with CPI. Differences in plasma levels were significant from 20 min after the initial injection to 135 min. We therefore conclude that epidural analgesia with CPI is superior to that with RII. However, it must be remembered that higher plasma levels may occur with CPI than with RII.

Epidural medication after the initial dose: reflections on current methods of administration during labour

Most women who receive epidural pain relief during labour require additional epidural analgesia following the initial dose. This review examines the relative merits associated with current methods of epidural drug delivery when further analgesia is required. Apart from considerations of patient safety and convenience the review compares the relative flexibility in pain management which can be provided by these different regimens. It is postulated that patient satisfaction is enhanced when the mother has some personal control over the density of neural blockade provided by epidural analgesia.

Midwive's assessment of the upper sensory level after epidural blockade

The ability of midwives to assess accurately the level of epidural blockade after a short period of instruction was examined. Seventy-two midwives estimated the upper level bilaterally in 100 patients, by detection of the loss of sensation to a cold stimulus. The midwife and anaesthetist were in complete agreement over the level of block in 71.5% of cases; the midwife overestimated the height of the block in 9.5% of cases, and underestimated in 19%. The midwife underestimated by three spinal segments in 1.5% of cases, and never by more. The technique was acceptable to patients and midwives alike. This procedure should enable safe management of obstetric analgesia, whoever administers top-ups; accurate detection of a block that recedes below therapeutic levels should facilitate earlier top-ups and thus reduce pain for the patient in labour.

Survey of the practice of epidural analgesia in a regional sample of obstetric units

An investigation into practices of the epidural services in a regional sample of obstetric units was undertaken following recent reported disasters associated with epidural analgesia for labour pain. A questionnaire was completed by all 22 obstetric units in the region, which included six teaching, 14 district and two independent centres. In three units the epidural service was shared with the obstetricians. A continuous anaesthetic presence was provided in 16 of 22 units. There was considerable variation in the attendance upon epidural patients by the anaesthetists. Instructions to midwives for top-ups and subsequent care of patients followed no uniform pattern. Midwife in-service training in the initial management of serious epidural complications and in cardiopulmonary resuscitation was inconsistent. In some units, the avoidance of aortocaval compression was not emphasised in the management of serious complications such as severe maternal hypotension, total spinal blockade or cardiac arrest of the parturient. The results obtained in this survey suggest that there is a need to review the requirements in the provision of obstetric epidural services and consideration should be given to the establishment of a generally accepted standard of practice.