Obstetric anesthesia practice in Canada.

PURPOSE: To describe obstetric anesthesia in Canada as practiced in 1997: to identify practices at variance with the literature and the opinions of experts: and to identify questions for future research. METHODS: In 1997, a detailed postal questionnaire asking about the practice of obstetric anesthesia was mailed to all 1,539 specialist anesthesiologist members of the Canadian Anaesthetists' Society residing in Canada. Nonresponders were mailed a second questionnaire three months later RESULTS: There were 865 completed questionnaires returned for analysis (56.2%). Of these, 522 anesthesiologists practiced obstetric anesthesia (60.3%). The data were subdivided into those from anesthesiologists with a full or part-time university based practice (40.1%) and those from a community based practice (59.9%). University based and community-based anesthesiologists have very similar patterns of practice. Specific areas where anesthesia practice was different from current recommendations included: (1) information provided when obtaining consent for labour epidural analgesia, (2) use of opioids and local anesthetics for initiation of epidural analgesia, (3) use of coagulation testing in preeclampsia, (4) the common use of cutting spinal needles, (5) use of neuraxial morphine and nonsteroidal anti-inflammatory agents after Cesarean deliveries, (6) optimal treatment of neuraxial opioid side effects, (7) when to insert an endotracheal tube for general anesthesia after delivery, and (8) withdrawing epidural catheters through epidural needles. CONCLUSIONS: This survey presents reference data on the practice of obstetric anesthesia in Canada in 1997. Anesthesiologists with university affiliation have very similar practices to those without university affiliations.

Comparison of 0.25 mg and 0.1 mg intrathecal morphine for analgesia after Cesarean section.

PURPOSE: To test the hypothesis that 0.1 mg intrathecal morphine plus NSAIDs provides satisfactory analgesia post-Cesarean section with fewer side effects than 0.25 mg intrathecal morphine. METHODS: Sixty women, scheduled for elective Cesarean section under spinal anesthesia, were randomized to receive either 0.1 mg or 0.25 mg intrathecal morphine combined with hyperbaric bupivacaine 0.75% and 20 microg fentanyl. All patients received a 100 mg indomethacin suppository at the end of surgery and 500 mg naproxen p.o. b.i.d. was started the evening of surgery and continued until discharge. A blinded researcher recorded the pain, pruritus, and nausea scores, the time to first request for additional analgesics, a visual analogue scale (VAS) satisfaction score, and the use of additional opioids, antipruritics, and/or antiemetics. RESULTS: Of the 60 patients enrolled, two were not included in the data analysis because of protocol violations leaving 30 patients in the 0.1 mg group and 28 in the 0.25 mg group. There were no differences in the VAS pain scores or the number of women requesting an opioid other than codeine between the two groups. The VAS pruritus scores in the 0.1 mg group were lower throughout the 24 hr (P < 0.001). Fewer women in the 0.1 mg group (4/30 vs 12/28) requested nalbuphine to treat itching (P = 0.018). Nausea scores were lower in the 0.1 mg group (P < 0.001). CONCLUSION: The use of 0.1 mg intrathecal morphine plus NSAIDs provides analgesia of similar quality to 0.25 mg but with fewer undesirable side effects following Cesarean section.

The changing role of magnesium sulphate therapy.

Magnesium sulphate is not an effective tocolytic. Magnesium sulphate therapy was also linked to preterm neonatal deaths in one study, which was stopped before completion. Other studies suggest a possible neuroprotective effect of magnesium. Both of these issues require further study. Magnesium sulphate is clearly the drug of choice to prevent recurrent eclampsia and to treat severe pre-eclampsia.

Comparison of epidural lidocaine and fentanyl to intrathecal sufentanil for analgesia in early labour.

A randomized, double-blind study was undertaken comparing an epidural test dose of lidocaine followed by 100 microg fentanyl (E-LF, n = 19) to combined spinal epidural sufentanil 10 microg (CSE-S, n = 21) in low risk women in early labour. The primary outcome measured was the duration of analgesia; secondary outcomes included the quality of analgesia, incidence and severity of pruritus, lower limb motor blockade, and the ability to ambulate. A P < 0.05 was considered statistically significant. Baseline demographic characteristics, including parity, were similar between groups. CSE-S provided analgesia of longer duration than E-LF (126 +/- 61 min versus 83 +/- 37 min, P < 0.01). Visual analog scores (VAS) for pain were higher with E-LF throughout the study period (P < 0.05) although patients in both groups had clinically acceptable analgesia. The VAS for pruritus were higher in the CSE-S group (P < 0.05) but no patient requested treatment for pruritus. Mild motor weakness was more frequent in the E-LF group (5/19 versus 20/21, P < 0.05) and fewer patients in the E-LF group met criteria for ambulation (13/19 versus 20/21, P < 0.05). While both E-LF and CSE-S provide effective analgesia for women in early labour, the more rapid onset of analgesia, lower VAS pain scores, longer duration of action and lesser impact on ability to ambulate suggest advantages of CSE-S over E-LF.

Prevalence of coagulation abnormalities associated with intrauterine fetal death.

PURPOSE: The purpose of this study was to determine factors associated with abnormal coagulation in the setting of intrauterine fetal death (IUFD). METHODS: We reviewed the charts of 238 patients diagnosed with IUFD over ten years. Data included demographics, co-existing obstetric disease and coagulation studies. A coagulation score was assigned based on the platelet count, prothrombin time, activated partial thromboplastin time and plasma fibrinogen concentration. Approximately 90% of the study population had coagulation scores < 4. A score of > or = 4 was considered abnormal. RESULTS: Complete coagulation analysis was available in 183/238 patients (77%) within 24 hr of delivery. One hundred and sixty-four of these (89.6%) had a coagulation score, < 4 and 19 had a score > or = 4 (10.4%). No relationship between the coagulation score and age, parity, gestational age at delivery, and number of days the dead fetus remained in utero was found. A coagulation score > = or 4 was associated with the presence of a pregnancy-related disease (P < 0.05), notably abruption (P < 0.001) and uterine perforation (P < 0.05). Four patients without co-existing disease (3.2%), had a coagulation score > or = 4. CONCLUSION: In most pregnancies complicated by fetal demise, the fetus and placenta are delivered within one week of fetal demise. The previously reported severe coagulation disturbances are largely eliminated by early delivery. Our study shows that coagulation abnormalities occur in some patients with uncomplicated IUFDs (3.2%) and that this number rises in the presence of abruption or uterine perforation.

Adding fentanyl 0.0002% to epidural bupivacaine 0.125% does not delay gastric emptying in laboring parturients.

Previous studies have shown that bolus doses of fentanyl (50 and 100 micrograms) with epidural bupivacaine delay gastric emptying by up to 45 min. We studied the effect of the addition of small-dose fentanyl to epidural bupivacaine infusions on gastric emptying during labor. The acetaminophen absorption technique was used to infer gastric emptying. Twenty-eight patients in established labor consented to participate in the study. They were randomized to receive either 1) 10 mL bupivacaine 0.125% followed by an infusion of 0.125% bupivacaine at 10 mL/h or 2) 10 mL bupivacaine 0.125% with 50 micrograms fentanyl followed by an infusion of 0.125% bupivacaine and 0.0002% fentanyl at 10 mL/h. Two hours after initiation of epidural analgesia, each patient ingested 20 mg/kg acetaminophen in a suspension of 150 mL water. Venous blood samples were drawn for a baseline and then every 15 min for 2 1/2 h. There were no significant demographic differences between the groups. There were no differences detected between groups in the peak plasma concentrations of acetaminophen, the time to achieve the peak plasma concentrations, or the area under the curve at 45 and 90 min. Our results indicate that epidural infusions for labor analgesia using 0.125% bupivacaine and 0.0002% fentanyl do not delay gastric emptying compared to infusions of bupivacaine 0.125% alone.

Factors associated with back pain after childbirth.

BACKGROUND: Back pain after childbirth is a frequent complaint. The purpose of this study was to determine the incidence of back pain 1-2 months post partum and to identify the factors, including epidural anesthesia for labor and delivery, that may predispose to it. METHODS: Women delivering a viable singleton infant were interviewed 12-48 h after delivery for a history of back pain that occurred before, during, or both before and during the recent pregnancy and for details of their delivery experience. Two months later, the women interviewed were sent a follow-up questionnaire regarding the occurrence of back pain 1-2 months post partum. RESULTS: Follow-up data were available for 1,042 (88%) of the 1,185 women originally interviewed. The incidence of post partum back pain in women who received epidural anesthesia was equivalent to those who did not (44% vs. 45%). Through stepwise multiple logistic regression, post partum back pain was found to be associated with a history of back pain, younger age, and greater weight. However, new-onset post partum back pain was found to be associated with greater weight and shorter stature. No statistically significant association was found between post partum back pain and epidural anesthesia, number of attempts at epidural placement, duration of second stage of labor, mode of delivery, or birth weight. CONCLUSIONS: The overall incidence of back pain 1-2 months post partum in this population was 44%. Predisposing factors were a history of back pain, younger age, and greater weight. Predisposing factors for new-onset post partum back pain were greater weight and shorter stature. Epidural anesthesia for labor and delivery did not appear to be associated with back pain 1-2 months post partum.

Epidural anesthesia for labor in an ambulatory patient.

The effectiveness of two epidural analgesic regimens on the ability to ambulate was compared in women in labor by a prospective, randomized, double-blind design. One group of patients received epidural fentanyl, a 75-micrograms bolus and an infusion of fentanyl 2.5 micrograms/mL at 15 mL/h (FENT, n = 53). A second group received ultra low-dose bupivacaine (0.04%), epinephrine (1.7 micrograms/mL), and fentanyl (1.7 micrograms/mL) (BEF, n = 77), a 15-mL bolus followed by an infusion at 15 mL/h. Adequate analgesia was rapidly obtained in 90.6% of patients in the FENT group and 92.2% of patients in the BEF group (P = 0.89). Seventy percent of patients in the FENT group ambulated versus 68% in the other group. The BEF mixture provided analgesia of longer duration (287 +/- 171 min versus 156 +/- 72 min, P = 0.0001). The number of patients delivering during administration of only their study drug (without needing higher doses of local anesthetics) was 52% for BEF and 21% for FENT (P = 0.0005). Hip flexion weakness precluding ambulation occurred in 17% (P = 0.002) of BEF patients and orthostatic hypotension in 9% (P = 0.08). Neither problem occurred in FENT patients. Neonatal outcome was similar in both groups. Approximately 70% of women receiving epidural analgesia with fentanyl or ultra low-dose bupivacaine, epinephrine, and fentanyl may ambulate safely during labor.

Epidural fentanyl and caesarean section: when should fentanyl be given?

Epidural fentanyl is often added to epidural local anaesthetic agents to improve the quality of anaesthesia obtained during Caesarean section. Fentanyl may be given either before or after delivery of the infant. When given before delivery, fentanyl has not been reported to cause neonatal depression, although this remains a concern. A prospective, randomized, double-blind study was undertaken to determine if fentanyl was more effective if given before or after delivery of the baby in 64 women undergoing Caesarean section under lidocaine epidural anaesthesia. Maternal outcome was determined by time to achieve T4 neural blockade, the dose of lidocaine necessary to achieve this block and intraoperative scores for pain, nausea, vomiting, shivering, and sedation. Neonates were assessed by umbilical arterial blood pH and Apgar scores. No differences were detected in either group with respect to maternal or neonatal outcome. We recommend using only epidural local anaesthetic agents before delivery, and giving epidural fentanyl following delivery of the infant.

Pulmonary hypertension and cardiomyopathy: anaesthetic management for caesarean section.

Pulmonary hypertension in pregnant women is uncommon but is associated with a high mortality. We present the case of a 14-yr-old parturient with pulmonary hypertension and cardiomyopathy who required a Caesarean section. Management goals included: (1) maintaining right ventricular function, (2) avoiding the haemodynamic effects of general endotracheal anaesthesia, and (3) minimizing narcotic-related neonatal respiratory depression. While most authors agree on invasive pulmonary and systemic monitoring, opinions differ as to the optimal method of providing anaesthesia for these patients. The successful use of lumbar epidural anaesthesia with lidocaine and fentanyl is described. When the local anaesthetic was administered slowly and in increments, epidural anaesthesia was safe for both mother and fetus.

Continuous suprascapular nerve block for analgesia of scapular fracture.

Fracture of the scapular is uncommon but painful. A case is described in which a comminuted scapular fracture was treated with a continuous suprascapular nerve block. With the patient lying supine an epidural needle was directed towards the scapular notch via a superior approach and an epidural catheter was placed when the notch was believed to have been identified. Repeat injections of 10 ml bupivacaine 0.25 per cent with 1/200,000 epinephrine provided analgesia within minutes and a duration of 8-10 hr. Injection of 10 ml radio-opaque dye demonstrated the catheter to be lateral to the scapular notch. However, dye dispersed throughout the supraspinous fossa including the scapular notch thus blocking the suprascapular nerve. This case demonstrates that continuous suprascapular nerve block can be performed for five days and that location of the scapular notch is less important than previously thought.