Mark C. Norris

Complications of labor analgesia : epidural versus combined spinal epidural techniques

Both epidural and combined spinal epidural (CSE) analgesia can provide maternal pain relief during labor. Currently, there are few data comparing the risks and complications of these two techniques. We recorded the incidence and severity of anesthetic-related complications in 1022 laboring parturients. Ninety-eight women opted for either no or parenteral analgesia, 388 chose epidural, and 536 requested CSE analgesia. Women choosing CSE analgesia most often received an intrathecal injection of sufentanil 10 micrograms at the time of epidural catheter insertion. The epidural catheters were then dosed as needed as the intrathecal analgesia waned. Women who received CSE analgesia were more likely to itch (41.4% vs 1.3%) or complain of nausea (2.4% vs 1.0%) or vomiting (3.2% vs 1.0%) than those receiving solely epidural analgesia. Patients who requested only epidural analgesia were more likely to suffer an unintended dural puncture (4.2% vs 1.7%). Fewer than 10% developed hypotension with either technique. The risk of headache was the same with both anesthetics (4%-10%) and did not differ from the incidence of headache in women not receiving neuraxial analgesia (10%-14%). Six patients required epidural blood patch for moderate to severe postural headache. Four of these women suffered a dural puncture with the 18-gauge Hustead epidural needle. The other two women had reportedly uncomplicated epidural and CSE analgesia. These data suggest either neuraxial analgesic technique can safely relieve the pain of labor. CSE analgesia is a safe alternative to epidural analgesia for labor and delivery.

Comparison among intrathecal fentanyl, meperidine, and sufentanil for labor analgesia

This study compared the analgesic efficacy of intermittent injections of intrathecal fentanyl (10 micrograms), meperidine (10 mg), or sufentanil (5 micrograms) administered to 65 parturients during the first stage of labor. The groups did not differ in onset or duration of effective analgesia. The meperidine group, however, had significantly lower pain scores once cervical dilation progressed beyond 6 cm. Side effects included mild pruritus and nausea. After intrathecal drug injection, variable decelerations of the fetal heart rate increased in the fentanyl and meperidine groups. All neonates had a 5-min Apgar score of 7 or more. We conclude that intermittent intrathecal injections of fentanyl, meperidine, or sufentanil can provide adequate first-stage labor analgesia. Meperidine appears to provide more reliable analgesia as the first stage of labor progresses.

Needle Bevel Direction and Headache after Inadvertent Dural Puncture

To study the effect of needle bevel direction on the incidence and severity of headache following inadvertent dural puncture occurring during the identification of the epidural space, the authors randomly assigned obstetric anesthesia residents to identify epidural space with the bevel of the epidural needle oriented either parallel or perpendicular to the longitudinal dural fibers. If dural puncture occurred, an observer unaware of the needle bevel direction, daily assessed the presence and severity of any subsequent headache. Of the 1,558 women who received epidural analgesia during this study, 41 women suffered dural puncture, 20 with the needle bevel oriented perpendicular to the longitudinal dural fibers and 21 with the needle bevel inserted parallel to the dural fibers (NS). Fourteen of 20 women in the group in which the needle bevel was perpendicular to dural fibers developed a moderate to severe headache, whereas only five of 21 in the group in which the needle bevel was parallel to dural fibers did so (P less than 0.005). Similarly, we administered a therapeutic blood patch to ten of 20 women in the perpendicular group but to only four of 21 in the parallel group (P less than 0.05). Thus, identifying the epidural space with the needle bevel oriented parallel to the longitudinal dural fibers limits the size of the subsequent dural tear and, therefore, lowers the incidence of headache should dural perforation occur.

Combined spinal-epidural versus epidural labor analgesia.

BackgroundDespite the growing popularity of combined spinal–epidural analgesia in laboring women, the exact role of intrathecal opioids and the needle-through-needle technique remains to be determined. The authors hypothesized that anesthetic technique would have little effect on obstetric outcome or anesthetic complications. MethodsData were prospectively collected from 2,183 laboring women randomly assigned to have labor analgesia induced with either 10 &mgr;g intrathecal sufentanil with or without 2.0 mg bupivacaine (n = 1,071) or 10 &mgr;g epidural sufentanil and 12.5–25.0 mg bupivacaine (n = 1,112). Immediately after induction, a continuous epidural infusion of 0.083% bupivacaine plus 0.3 &mgr;g/ml sufentanil was begun in all patients and continued until delivery. Labor was managed by nurses, obstetricians, and obstetric residents who were unaware of the anesthetic technique used. ResultsAnesthetic technique lacked impact on our primary outcome: mode of delivery or labor duration. Infants whose mothers were allocated to the combined spinal–epidural group had a slightly higher umbilical artery carbon dioxide partial pressure (54.2 ± 10.4 vs. 53.2 ± 10.2 mmHg). However, only achieving at least 5 cm cervical dilation before induction of analgesia and having a cesarean delivery were independent risk factors for elevated umbilical artery carbon dioxide partial pressure. The frequencies of accidental dural puncture, failed epidural analgesia, headache, and epidural blood patch were low and similar in the two groups. ConclusionsLabor progress and outcome are similar among women receiving either combined spinal–epidural or epidural analgesia. The difference in neonatal outcome appears related to the presence of confounding variables. The combined spinal– epidural technique is not associated with an increased frequency of anesthetic complications. Either technique can safely provide effective labor analgesia.

Safety Steps for Epidural Injection of Local Anesthetics: Review of the Literature and Recommendations

E pidural postoperative analgesia is a popular technique that may improve patient comfort and outcome while reducing hospital costs (1,2). However, significant risks accompany the injection of local anesthetic into the epidural space, including unintentional subdural, subarachnoid, and intravenous (IV) drug injection. Despite years of use, controversy still surrounds the appropriate steps to ensure the safe initiation of epidural anesthesia.

Risk of respiratory arrest after intrathecal sufentanil.

I ntrathecal (IT) sufentanil provides profound labor pain relief without significant autonomic or motor blockade. Common side effects include pruritus, sedation, and nausea (1). More serious complications, such as high sensory level, respiratory depression, and apnea, have been reported (2-4). After observing a respiratory arrest after 10 pg IT sufentanil, we reviewed six years of labor anesthetics to estimate the frequency of serious complications accompanying IT sufentanil and epidural local anesthetics.

Patient variables and the subarachnoid spread of hyperbaric bupivacaine in the term parturient.

To determine if age, height, weight, body mass index, or vertebral column length significantly influence the distribution of sensory analgesia or anesthesia after subarachnoid injection of hyperbaric bupivacaine, 52 women presenting for cesarean section were studied. All received 15 mg hyperbaric bu

Does epinephrine improve the diagnostic accuracy of aspiration during labor epidural analgesia

UNLABELLED Aspiration reliably detects almost all IV multiorifice epidural catheters. Although a supplemental epinephrine 15-microg test dose may detect the rare IV catheter that does not yield blood on aspiration, false-positive epinephrine responses may cause some women to unnecessarily undergo repeat epidural catheter insertion. We evaluated 532 consecutive eligible patients requesting neuraxial labor analgesia. Patients were excluded if they had a contraindication to epinephrine or if they received intrathecal sufentanil/bupivacaine. Multiorifice catheters were inserted 4-6 cm into the epidural space as part of an epidural (n = 305) or combined spinal-epidural (n = 270) technique. We used aspiration, a lidocaine/epinephrine test dose, and bolus injection or infusion of dilute bupivacaine/sufentanil solutions to systematically determine IV, intrathecal, or epidural catheter location. Aspiration alone detected 47 of 48 intravascular catheters. There were 10 positive epinephrine responses: 2 were true positives, 7 were falsely positive (subsequent local anesthetic injection/infusion produced bilateral sensory change and analgesia), and 1 catheter was removed without further testing. Aspiration detected almost all intravascular catheters. Although the epinephrine test dose did detect one catheter that proved to be in a blood vessel, 87.5% of positive responses occurred in women without intravascular catheters. IMPLICATIONS Epidural catheters may enter a blood vessel. Many clinicians use epinephrine to detect these catheters. Because aspiration alone detects almost all IV multiorifice catheters in laboring women, a subsequent epinephrine test dose may be unnecessary.

Incidence of electrocardiographic changes during cesarean delivery under regional anesthesia.

Serial electrocardiograms were obtained on 93 healthy ASA physical status I and II term parturients during nonemergent cesarean delivery under regional anesthesia. Electrocardiographic changes occurred in 44 of the 93 patients (47.3%); in 35 of these 44 patients, the changes were characteristic, or suggestive, of myocardial ischemia. Symptoms of chest pain, pressure, and dyspnea occurred in 15 of the 44 patients with electrocardiographic changes; no patient without electrocardiographic change developed symptoms of chest pain, pressure, or dyspnea. Small but statistically significant differences were noted in heart rate, diastolic and systolic arterial pressures, and rate-pressure product between the patients with electrocardiographic changes and those without. The authors speculate that myocardial ischemia is a likely cause of both the electrocardiographic changes seen in these patients and of the symptoms of chest pain and dyspnea that they sometimes experience.

Height, weight, and the spread of subarachnoid hyperbaric bupivacaine in the term parturient.

Using a standardized technique, spinal anesthesia was induced in 50 term parturients to study the correlation between patient height, weight, and body mass index (BMI) and the spread of sensory blockade. All patients received 12 mg hyperbaric bupivacaine while in the right lateral decu-bitus positio