Lumbar ultrasound: useful gadget or time-consuming gimmick?

Despite widespread enthusiasm for using lumbar ultrasound in obstetrics, there are some who believe it is expensive and time-consuming, with undetermined risks and uncertain benefits. For decades, anesthesiologists have striven to perfect the identification and cannulation of the epidural space using skills learned during training and early clinical practice. These skills include knowledge of the relevant anatomy and detection of subtle tactile clues that aid successful placement of an epidural catheter. Indeed, obstetric anesthesiologists have managed to do this with great success without using imaging techniques. There is a long learning curve associated with lumbar ultrasound and it is unclear from the literature if the success rates associated with its use are superior to clinical skill alone. Is it only a matter of time before regulators insist that lumbar ultrasound is used before inserting an epidural? Indeed, this has already happened for central vein catheters. The United States spent $2.2 trillion on health care in 2007, nearly twice the average of other developed nations. If rapid health cost growth persists, one out of every four dollars in the US national economy will be tied up in the health system by 2025. Do obstetric anesthesiologists want to add to these costs by using unnecessary and expensive equipment? Although many feel that diagnostic ultrasound in obstetrics is safe, some argue that we have yet to perform an appropriate risk analysis for lumbar ultrasound during pregnancy. The issue of ultrasound bio-safety needs to be considered before we all jump on the ultrasound bandwagon.

Anesthetic management of a pregnant woman with Gorham-Stout disease.

Gorham-Stout disease is a rare disorder of bone loss and proliferation of lymphatic and vascular tissue (lymphangiomatosis). A 30-year-old nulliparous woman with Gorham-Stout disease presented at 8weeks of gestation with a fused cervical spine. At 31weeks she developed basilar invagination and neurological symptoms that were managed with a neck brace. Anesthetic considerations were those of airway compromise, development of severe preeclampsia and Kasabach-Merritt coagulopathy. Elective tracheostomy was declined. She presented two days before a planned cesarean delivery at 35weeks in preterm labor. A semi-urgent cesarean delivery under spinal anesthetic proceeded uneventfully, with an otolaryngologist present in case a surgical airway was required. Mother and baby were discharged home after three days. Maternal postpartum recovery was complicated by episodes of respiratory compromise and critical bone loss in the cervical spine, necessitating further surgical reinforcement.

A randomized comparison of a five-minute versus fifteen-minute lockout interval for PCEA during labor.

BACKGROUND: The best combination of bolus size and lockout interval for patient-controlled epidural analgesia (PCEA) is not known. This study compared a 5-min with a 15-min lockout interval. METHODS: Parturients were randomly assigned to receive PCEA with either a 5-min or a 15-min interval. All had a 15-mL loading dose, continuous background infusion 6 mL/h of 0.125% bupivacaine plus fentanyl 2 mug/mL, PCEA bolus volume 5 mL, maximum hourly dose 26 mL. Visual analogue scores for pain, nausea and pruritus, sensory levels to ice, sacral analgesia, motor power, blood pressure and fetal heart rate were assessed pre-epidural and regularly thereafter until delivery. The numbers of boluses and attempts and patient satisfaction were recorded. RESULTS: 29 patients were assigned to the 5-min group and 31 to the 15-min group, but the 15-min group contained twice as many nulliparous women. Side-effect and complication rates did not differ between groups. VAS pain scores were reduced from a median of 79 in the 15-min group and 82 in the 5-min group to a median of zero 30 min after epidural insertion. Bolus/attempt ratio was 0.88 in the 5-min vs. 0.70 in the 15-min group. The numbers of requests for physician intervention were similar. No differences in pain scores, side-effects, drug use or patient satisfaction were demonstrated. CONCLUSION: The 5-min lockout interval appears the more efficient and has been used safely in our practice for 15,000 parturients, although a larger study is required to confirm the relative efficacy, efficiency and safety of this regimen.

A randomized study of combined spinal-epidural analgesia versus intravenous meperidine during labor: impact on cesarean delivery rate.

BACKGROUND: Combined spinal-epidural (CSE) analgesia produces rapid-onset pain relief and allows ambulation in early labor. Epidural local anesthetics may contribute to an increase in operative deliveries by decreasing perineal sensation and causing motor weakness. Operative delivery rates might be reduced with CSE, by avoiding or delaying administration of local anesthetics. This study compares the operative delivery rates associated with a CSE technique and those associated with intravenous meperidine for labor analgesia. METHODS: Healthy parturients at full term were assigned randomly to receive CSE or intravenous meperidine analgesia. The CSE group received 10 microg intrathecal sufentanil, followed by epidural bupivacaine and fentanyl at their next request for analgesia. Parturients receiving intravenous meperidine had 50 mg on demand (maximum, 200 mg in 4 h). Labor and delivery outcomes in both groups were recorded and compared. RESULTS: An intent-to-treat analysis of 1,223 women indicated that CSE does not increase the rate of cesarean delivery for dystocia in nulliparous and parous women (CSE, 3.5% vs. intravenous meperidine, 4; P=not significant) or in nulliparous women alone (CSE, 7% vs. intravenous meperidine, 8%; P=not significant). Profound fetal bradycardia that necessitated emergency cesarean delivery within 1 h of the time the mother received sufentanil occurred in 8 of 400 parturients (compared with 0 of 352 who received meperidine; P < 0.01). However, the method of fetal monitoring differed between the two groups. Despite this, neonatal outcomes were similar overall. CONCLUSIONS: Combined spinal-epidural analgesia during labor does not increase the cesarean delivery rate for dystocia in healthy parturient patients at full term, regardless of parity. However, an unexpected increase in the number of cesarean deliveries for profound fetal bradycardia after intrathecal sufentanil was observed. Further investigation is warranted.

Randomized trial of epidural versus intravenous analgesia during labor.

OBJECTIVE: To compare the effects of epidural analgesia with intravenous (IV) analgesia on the outcome of labor. METHODS: Thirteen hundred thirty women with uncomplicated term pregnancies and in spontaneous labor were randomized to be offered epidural bupivacaine-fentanyl or IV meperidine analgesia during labor. RESULTS: Comparison of the allocation groups by intent to treat revealed a significant association between epidural allocation and operative delivery for dystocia. However, only 65% of each randomization group accepted the allocated treatment. Four hundred thirty-seven women accepted and received meperidine as allocated, and they were compared with 432 women accepting epidural allocation. Significant associations resulted between epidural administration and prolongation of labor, increased rate of oxytocin administration, chorioamnionitis, low forceps, and cesarean delivery. Because of the high rate of noncompliance with treatment allocation, a multifactorial regression analysis was performed on the entire cohort, and a twofold relative risk of cesarean delivery persisted in association with epidural treatment. The impact of epidural treatment on cesarean delivery was significant for both nulliparous and parous women (risk ratios 2.55 and 3.81, respectively). Epidural analgesia provided significantly better pain relief in labor than did parenteral meperidine. CONCLUSION: Although labor epidural analgesia is superior to meperidine for pain relief, labor is prolonged, uterine infection is increased, and the number of operative deliveries are increased. A two- to fourfold increased risk of cesarean delivery is associated with epidural treatment in both nulliparous and parous women.

Rectal indomethacin potentiates spinal morphine analgesia after caesarean delivery.

This double-blind, randomized study was designed to evaluate the use of indomethacin (Indocid, MSD) following caesarean delivery performed under spinal anaesthesia. Thirty ASA I-II women presenting for elective caesarean were recruited. Spinal anaesthesia was performed in a standard manner using hyperbaric bupivacaine, fentanyl and morphine. At the completion of surgery, subjects were administered two rectal suppositories, followed by 12-hourly suppositories for six doses (three days). The study group received 100 mg indomethacin suppositories and controls were given placebo (Anusol). Data collected included Visual Analog Scale (VAS) pain scores at rest and with movement, VAS scores for nausea and itch, and analgesic use. Demographic data were similar in the two groups. Median time to first analgesia (TTFA) was nine hours in the control group v. 39.5 hours in the indomethacin group (P < 0.003). Additional analgesic requests throughout the postoperative period were less in women who received indomethacin: 4 v 11 (P < 0.001). Women who received indomethacin had significantly less pain on the first postoperative day, especially on movement: mean VAS 1.4 v 5.1 (P < 0.00001). There were no reported adverse neonatal or maternal effects from the use of indomethacin. Rectal indomethacin use following caesarean delivery leads to significantly improved pain relief compared with placebo. The combination of spinal morphine and rectal indomethacin leads to high-quality postoperative analgesia.

Comparison of 26-gauge Atraucan and 25-gauge Whitacre needles: insertion characteristics and complications.

Ninety-six women undergoing post-partum tubal ligation under spinal anaesthesia were studied to compare 26G Atraucan with 25G Whitacre spinal needles for ease of insertion, number of attempts at needle insertion, cerebrospinal fluid (CSF) flow characteristics through the needles, quality of subsequent analgesia, and incidence of perioperative complications. A higher rate of successful dural puncture at the first attempt (40/50 vs 27/46, P < 0.05) and faster (mean +/- SD, 11.5 +/- 2.2 vs 13.5 +/- 2.4, P < 0.001) CSF flow through the needle was achieved with the Atraucan than with the Whitacre needle. The incidence of failed spinal (4% vs 5%) and post-dural puncture headache (PDPH) (4% vs 4.3%) was similar with both needles, but more patients experienced paraesthesiae during needle insertion with the Whitacre than with the Atraucan needle (15% vs 2%, P < 0.05). We conclude that the use of the 26G Atraucan needle is associated with a higher rate of successful identification of the subarachnoid space at the first attempt, faster CSF backflow, and fewer paraesthesia when compared with the 25G Whitacre needle.

Use of sevoflurane during elective cesarean birth: a comparison with isoflurane and spinal anesthesia.

This randomized study compared sevoflurane 1% and isoflurane 0.5% in terms of maternal and neonatal outcomes. In addition, neonatal outcome in both groups was compared with a cohort of patients delivered by cesarean birth using spinal anesthesia. Fifty-five patients presenting for elective cesarean birth under general anesthesia were randomly assigned to receive either sevoflurane 1% or isoflurane 0.5% in a 50% nitrous oxide and oxygen mixture for maintenance. Twenty patients requesting regional anesthesia received a subarachnoid block using 1.5 mL bupivacaine 0.75% in 8.25% dextrose with fentanyl 10 micrograms. Intraoperative hemodynamic variables and perioperative adverse events were recorded. Neonatal data included Apgar scores at 1 and 5 min, umbilical artery gas analysis, neurologic adaptive capacity scores (NACS) at 2 and 24 h, and a modified neonatal behavioral assessment scale (NBAS) at 24 h. Sevoflurane and isoflurane at equianesthetic concentrations (0.46 MAC-h [minimum alveolar anesthetic concentration hours]) were associated with similar blood pressure and heart rate changes during the operation. Blood loss, uterine tone, and perioperative complications were not problematic and were similar with the two drugs. No differences were seen in emergence times or in the time to being judged fit for discharge from the recovery room. Similarly, the level of postoperative comfort was the same in both groups. Comparing the general and the spinal anesthetic groups, no differences could be detected in neonatal outcome. Fluoride concentrations were modestly increased above preoperative levels in maternal and umbilical blood samples after sevoflurane administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Patient-controlled analgesia following caesarean section under general anaesthesia: a comparison of fentanyl with morphine.

This prospective, randomised, double-blind study compared PCA fentanyl with PCA morphine for post-Caesarean section analgesia. Following a standardised general anaesthetic, 37 women were allocated to receive either fentanyl (n = 18) or morphine (n = 19). The PCA was commenced after the women had been made comfortable in the postanaesthetic recovery room with the appropriate opioid solution (mean dose required = fentanyl 375 micrograms or morphine 16 mg). Initial PCA settings were bolus 1 ml (fentanyl 25 micrograms or morphine 1 mg), lockout time ten minutes, and no background infusion. Both analgesic solutions provided effective analgesia for a mean of 37 hr with high levels of patient satisfaction, and there were no differences in VAS scores for pain and patient satisfaction, or for side effects (nausea, itch, and sleepiness) between fentanyl or morphine. However, more patients in the fentanyl group required supplementary boluses or alterations to the PCA settings (13/18 vs 4/19: P = 0.005), and one patient was removed from the study due to inadequate analgesia. We conclude that fentanyl is not recommended for routine PCA use following Caesarean section.

Anesthetic management of a parturient with mixed mitral valve disease and uncontrolled atrial fibrillation.

This case report describes the anesthetic management of a 32-year-old parturient with combined severe mitral regurgitation and moderate mitral stenosis, complicated by fast atrial fibrillation. The advantageous effects of epidural analgesia during labor and vaginal delivery and the importance of invasive monitoring are discussed. We also report the rare complication of right bundle branch block related to the use of a pulmonary artery catheter.