Predicting prolonged fetal heart rate deceleration following intrathecal fentanyl/bupivacaine.

BACKGROUND: Intrathecal opioids for labor analgesia are occasionally associated with fetal heart rate abnormalities. We wanted to identify risk factors for this occurrence. METHODS: The fetal tracings of 151 consecutive patients were reviewed for the period including 30 min before and 60 min after combined spinal-epidural analgesia using intrathecal bupivacaine with fentanyl. Their progress of labor at injection was also recorded. RESULTS: Lack of fetal head engagement (odds ratio 5.5, 95% CI 2.1-14.2) and the presence of variable fetal heart rate decelerations (odds ratio 3.6, 95% CI 1.6-8.4) were associated with prolonged fetal heart rate deceleration after combined spinal-epidural analgesia. CONCLUSION: This case-control study suggests that if the fetal head is not engaged or if the fetus is experiencing variable decelerations, there is an increased risk of prolonged fetal heart rate deceleration following intrathecal fentanyl/bupivacaine. This finding must now be confirmed in a cohort study.

Glass recycling in the labour suite is environmentally sound and economical.

BACKGROUND: Glass bottles are used for the storage of local anaesthetics in the US and are recyclable. Recycling would result in hospital solid waste reduction. METHODS: The members of the Department of Anaesthesia were surveyed to determine where these local anaesthetic bottles were disposed of. From November 2002 to April 2003, glass bottles used on the labour and delivery suite were saved for recycling. The number of bottles and the weight recycled were recorded. The number of procedures involving anaesthesia were also recorded during this time period. RESULTS: Residents dispose of the local anaesthetic bottle in the sharps container while consultants dispose of them in the trash (P<0.05). Both means of disposal are not recycled in the US. The average amount of glass recycled per month was 19.37 (3.15) kg. Our hospital pays $0.46/kg (0.26 UK pound/kg) for sharps disposal. By not disposing of the glass in the sharps container, the average savings per month was $8.95 (1.45) (5.15 UK pounds (0.84)). CONCLUSION: The recycling of glass is good for the environment through waste reduction and results in small savings to the hospital.

Effects of immediately initiating an epidural infusion in the combined spinal and epidural technique in nulliparous parturients.

BACKGROUND AND OBJECTIVES: Intrathecal fentanyl with bupivacaine provides rapid labor analgesia of limited duration. We investigated the effect of initiating an epidural infusion of 0.1% ropivacaine with fentanyl 2 microg/mL and epinephrine 1:400,000 (REF) on the duration of analgesia and incidence of side effects after intrathecal injection in the combined spinal and epidural technique. METHODS: Thirty-four nulliparous parturients with a cervical dilation of 3 to 5 cm were randomized to receive epidural saline or REF at 10 mL following the intrathecal injection of fentanyl 25 microg and bupivacaine 2.5 mg. Degree of analgesia, severity of pruritus, motor block, blood pressure, and sensory level to coolness were assessed until the patient requested additional analgesia. RESULTS: Analgesia was significantly longer in the REF group, 158.4 +/- 59.6 minutes versus 103.8 +/- 26.2 minutes. The decrease in blood pressure compared with the blood pressure at intrathecal injection was greater for the REF group at all times, but achieved statistical significance at 60 minutes. There was no difference in ephedrine use, pruritus, or motor block between groups. There was no difference in sensory level to coolness at 90 minutes after intrathecal injection between groups. CONCLUSIONS: Initiating an infusion of REF prolongs the duration of analgesia, but also results in a greater decrease in blood pressure. Despite this effect on blood pressure, there was no difference in ephedrine use.

Comparison of combined spinal-epidural and low dose epidural for labour analgesia.

PURPOSE: To compare the combined spinal-epidural (CSE) technique with the epidural technique with regard to time to initiate and manage, motor block, onset of analgesia and satisfaction during labour. METHODS: Upon requesting analgesia, 50 healthy term parturients were randomized in a prospective, double-blind fashion to receive either CSE analgesia or lumbar epidural analgesia in the labour floor of a university hospital at an academic medical centre. The epidural group (n = 24) received bupivacaine 0.0625%-fentanyl 0.0002% with 0.05 ml in 10 ml local anesthetic sodium bicarbonate 8.4% and epinephrine 1:200,000. The CSE group (n = 26) received intrathecal 25 microg fentanyl and 2.5 mg bupivacaine. Additional analgesia was provided upon maternal request. RESULTS: There were no differences (P>0.05) in time to perform either technique, motor blockade, or parturient satisfaction or in the number of times that the anesthesiologist was called to perform any intervention. Although the first sign of analgesia was not different between the two groups, the onset of complete analgesia was more rapid with the CSE technique (Visual Analogue Pain Score (VAPS) at five minutes < three: 26/26 vs. 17/24, P+/-0.001). CONCLUSION: Although epidural analgesia with a low concentration of local anesthetic and opioid mixture takes longer to produce complete analgesia, it is a satisfactory alternative to CSE.

Obstetricians' ability to assess the airway.

OBJECTIVES: To assess the ability of obstetricians to recognize parturients at risk for difficult intubation and to examine the effect of education in airway examination on that ability. METHODS: The airways of 160 parturients were examined by four physicians: one attending and one resident obstetrician, and one attending and one resident anesthesiologist. After each airway examination, the physicians completed questionnaires about possible difficult intubation, use of antepartum consultation, and choice of analgesia early in labor. RESULTS: Instruction in airway examination did not affect obstetricians' ability to assess airways. Compared with the attending anesthesiologist's opinion, the sensitivity and specificity of the attending obstetrician before instruction were 0.59 and 0.82, respectively, and for the obstetric resident, 0.41 and 0.89, respectively. After instruction, the sensitivity and specificity for the obstetric attending physician were 0.60 and 0.83, respectively and for the obstetric resident, 0.50 and 0.87, respectively. In airways judged possible difficult intubations by the obstetricians, instruction did not affect the use of antepartum consultation or early epidural analgesia by the residents. In the obstetric attending physicians there was a significant increase in use of early epidural analgesia. CONCLUSION: Although instruction in airway examination did not affect obstetricians' ability to predict difficult airways, it did affect treatment of labor analgesia.

Comparison of three different doses of intrathecal fentanyl and sufentanil for labor analgesia.

STUDY OBJECTIVE: To compare the duration of analgesia and incidence of side effects of three doses of intrathecal fentanyl (25 micrograms, 37.5 micrograms, 50 micrograms) with three doses of intrathecal sufentanil (5 micrograms, 10 micrograms, 15 micrograms). DESIGN: Randomized, double-blind study. SETTING: Labor suite of the Hospital of the University of Pennsylvania. PATIENTS: 60 ASA physical status I and II parturients in active labor who requested analgesia. INTERVENTIONS: Patients received one of the six doses of opioid diluted with normal saline to achieve a volume of 1.5 ml intrathecally. MEASUREMENTS AND MAIN RESULTS: Duration of analgesia, contraction pain, degree of pruritus, maternal blood pressure, maternal heart rate, fetal heart rate, Apgar scores, and neurologic and adaptive capacity scores were measured. There was no statistical difference among the doses of fentanyl in duration of analgesia. In addition, there was no statistical difference among the doses of sufentanil. The durations of analgesia for all doses of sufentanil were statistically longer than that for all doses of fentanyl. There was no difference among all the groups for maximal pruritus score. The duration of pruritus did not differ among doses of fentanyl or sufentanil; the duration of pruritus was significantly longer for sufentanil. All groups had a decrease in blood pressure. There was no difference among the groups in regard to the effect on the systolic or diastolic blood pressure. CONCLUSIONS: Intrathecal sufentanil produced analgesia of longer duration than fentanyl for all doses studied. The duration of pruritus with sufentanil was also longer.

Preemptive epidural analgesia and recovery from radical prostatectomy: a randomized controlled trial.

CONTEXT: Preemptive analgesia can decrease the sensitization of the central nervous system that would ordinarily amplify subsequent nociceptive input, but a clear demonstration of its clinical efficacy is necessary for it to become a routine component of acute pain therapy. OBJECTIVE: To determine the impact of preemptive epidural analgesia on postoperative pain and other clinically important outcome variables after radical retropubic prostatectomy. DESIGN AND SETTING: A block randomized double-blind clinical trial lasting 20 months at a single academic medical center. PATIENTS: A total of 100 generally healthy and neurologically intact patients scheduled for radical retropubic prostatectomy for the treatment of prostate cancer in whom an epidural catheter for treating postoperative pain was to be placed prior to the induction of general anesthesia. INTERVENTIONS: Epidural bupivacaine, epidural fentanyl, or no epidural drug was administered prior to induction of anesthesia and throughout the entire operation, followed by aggressive postoperative epidural analgesia for all patients. MAIN OUTCOME MEASURES: Daily pain scores during hospitalization and pain scores obtained 3.5, 5.5, and 9.5 weeks after hospital discharge. RESULTS: The patients who received epidural fentanyl or bupivacaine prior to surgical incision (preemptive analgesia) experienced 33% less pain while hospitalized (P=.007). Pain scores in those receiving preemptive analgesia were significantly lower at 9.5 weeks (P=.02), but were not significantly different at 3.5 or 5.5 weeks. At 9.5 weeks, 32 (86%) of 37 patients receiving preemptive analgesia were pain-free compared with 9 (47%) of 19 control patients (P=.004). Patients receiving preemptive analgesia were more active 3.5 weeks after surgery (P=.01), but not at 5.5 or 9.5 weeks. CONCLUSIONS: Even in the presence of aggressive postoperative pain management, preemptive epidural analgesia significantly decreases postoperative pain during hospitalization and long after discharge, and is associated with increased activity levels after discharge.

Neonatal outcome and mode of delivery after epidural analgesia for labour with ropivacaine and bupivacaine: a prospective meta-analysis.

In this prospective meta-analysis, we have evaluated the effect of epidural analgesia with ropivacaine for pain in labour on neonatal outcome and mode of delivery compared with bupivacaine. In six randomized, double-blind studies, 403 labouring women, primigravidae and multiparae, received epidural analgesia with ropivacaine or bupivacaine 2.5 mg ml-1. The drugs were administered as intermittent boluses in four studies and by continuous infusion in two. Apgar scores, neurological and adaptive capacity scores (NACS), degree of motor block and mode of delivery were recorded. The studies were designed prospectively to fit meta-analysis of the pooled results. Results showed similar pain relief and consumption of the two drugs. In the vaginally delivered neonates, NACS scores were approximately equal for both groups at 2 h, but at 24 h there were fewer infants with NACS less than 35 in the ropivacaine compared with the bupivacaine group (2.8% vs 7.6%; P < 0.05). Spontaneous vaginal deliveries occurred more frequently overall with ropivacaine than with bupivacaine (58% vs 49%; P < 0.05) and instrumental deliveries (forceps and vacuum extraction) less frequently (27% vs 40%; P < 0.01), while the frequency of Caesarean section was similar between groups. The intensity of motor block was lower with ropivacaine. There were no significant differences in adverse events.

Epidural lidocaine for cesarean delivery of the distressed fetus.

Lidocaine with epinephrine and sodium bicarbonate has a rapid onset of action. We therefore wished to compare its use with that of chloroprocaine for urgent cesarean delivery. Thirty parturients for cesarean section under epidural anesthesia were divided into three groups. Group 1 required elective cesarean section and served as the control group for neonatal lidocaine levels. Groups 2 and 3 had been receiving epidural infusions of 0.125% bupivacaine with epinephrine 1:400,000 and required urgent cesarean section. They were randomized to receive either 1.5% lidocaine with epinephrine or 3% chloroprocaine, both with sodium bicarbonate 2 ml in a total volume of 25 ml. All patients had adequate anesthesia and none required supplementation. The time from completion of injection to the achievement of a T4 sensory level was significantly shorter in the chloroprocaine group (3.1 vs. 4.4 min). There were no differences in Apgar scores or Neurologic and Adaptive Capacity Scores between the lidocaine and chloroprocaine groups. Lidocaine was detectable in maternal serum from four of the urgent cases and all of the elective cases. It was detectable in five neonates from the elective group but none from the emergency group. In parturients with preexisting epidural catheters and a baseline epidural infusion to maintain a T10 sensory level, chloroprocaine is faster in onset than lidocaine, but the difference in this study was only 1.3 min, and both agents provided excellent anesthesia.

Comparison of 0.25% ropivacaine and bupivacaine for epidural analgesia for labor and vaginal delivery.

STUDY OBJECTIVE: Part 1: To measure ropivacaine levels in the mother and infant at delivery after continuous lumbar epidural infusion. Part 2: To compare epidural ropivacaine to epidural bupivacaine for labor analgesia in regard to effectiveness, motor blockade, and maternal and neonatal effects. DESIGN: Part 1: Open-labelled, non-blind study. Part 2: Randomized, double-blind study. SETTING: Labor and delivery units of two academic hospitals. PATIENTS: Part 1: 20 ASA physical status I and II parturients in active labor. Part 2: 81 ASA physical status I and II parturients in active labor. INTERVENTIONS: For Part 1, 8 to 12 ml of 0.25% ropivacaine was administered through a lumbar epidural catheter to achieve a T10 dermatomal sensory level. An infusion of 0.25% ropivacaine, 8 to 10 ml/hr, maintained this sensory level. Maternal and umbilical cord blood samples obtained at delivery were analyzed for ropivacaine concentration. For Part 2, anesthetic management was similar to that previously described except patients were randomized to receive either 0.25% ropivacaine or 0.25% bupivacaine. Onset, regression, maximal spread of sensory block, and onset and degree of motor blockade were measured. Contraction pain as assessed using a visual analog scale (VAS), maternal blood pressure, and heart rate were determined every 5 minutes until a stable VAS-contraction score was achieved, and every 30 minutes thereafter. Neonatal assessment included Apgar scores and neurologic and adaptive capacity scores (NACS) at 15 minutes, 2 hours, and 24 hours. MEASUREMENTS AND MAIN RESULTS: For Part 1, the total and free maternal arterial concentrations of ropivacaine at delivery were 0.64 +/- 0.14 microgram/ml and 0.10 +/- .02 microgram/ml, respectively; the umbilical venous total and free concentrations were 0.19 +/- 0.03 microgram/ml and 0.12 +/- 0.07 microgram/ml, respectively (n = 12). The umbilical arterial and venous concentrations did not differ for both the free and total concentrations. For Part 2, there was no difference between ropivacaine and bupivacaine in the variables measured. Umbilical cord gases and Apgar scores were not different between the two groups; NACS were higher at 15 minutes and 2 hours in the ropivacaine group (p < 0.05) than the bupivacaine group. CONCLUSION: Both ropivacaine and bupivacaine produced excellent analgesia for labor with no major adverse effect on the mother or neonate.

Normal saline i.v. fluid load decreases uterine activity in active labour.

This study was designed to observe the effects of i.v. fluid infusion on uterine activity during normal labour in women receiving an extradural block. Thirty-four women in spontaneous labour at term gestation were allocated randomly and prospectively to one of three i.v. pre-extradural fluid load groups: group A, no fluid load; group B, normal saline 500 ml; and group C, normal saline 1000 ml. Continuous internal measurement of uterine activity was observed before, during and after fluid infusion and extradural block. In groups A and B, uterine activity did not change. In group C, uterine activity decreased after infusion of saline (P < 0.01) and returned to baseline over the next 20 min. Extradural block was not associated with a change in uterine activity. Hypotension was not increased in the group that received no fluid preload.

Major conduction anesthesia in a patient with Klippel-Trenaunay Syndrome.

The successful management of major conduction anesthesia in a patient with Klippel-Trenaunay syndrome is discussed. This case illustrates that major conduction anesthesia can be safely used if proper imaging studies are obtained, if one is aware of the underlying disease process, and if there is no port wine lesion in the dermatomal area corresponding to the spinal segment where the needle is to be inserted.

Epidural lidocaine versus 2-chloroprocaine for fetal distress requiring urgent cesarean section.

Chloroprocaine is a local anesthetic widely used for the urgent cesarean delivery of a distressed fetus in an mother with a epidural catheter because of its quick onset and short half-life. However, chloroprocaine has disadvantages that include decreased effectiveness of subsequently administered epidural amides and narcotics. Lidocaine with freshly added epinephrine and sodium bicarbonate is also rapid in onset, although there is the theoretical concern regarding the accumulation of ionized lidocain in the acidotic fetus. A retrospective review revealed that though the drug administration to incision time was significantly faster (P < 0.005) for 3% chloroprocaine, both 3% chloroprocaine and 1.5% lidocaine were clinically effective. There were no differences in neonatal Apgar scores or neonatal umbilical cord pH values between the two treatment populations, offering lidocaine as an attractive alternative to chloroprocaine.

Anesthetic considerations in premature birth.

Premature birth still accounts for about 75% of perinatal mortality. Although great strides have been made in the care of premature babies over the past two decades, markedly decreasing mortality, the prevention of premature birth has not been greatly improved. Although tocolysis, particularly with the beta-2 agonists and magnesium sulfate, may delay birth and allow fetal maturation, it poses several risks which, if not recognized, can cause serious morbidity and even mortality. The use of these drugs and other less widely used tocolytics has important implications for the anesthesiologist. The premature infant itself is subjected to such risks as RDS, IVH, NEC, asphyxia, hypothermia, increased incidence of breech presentation, metabolic disturbances, and predisposition for trauma. To ensure safe delivery, premature babies should be delivered in a tertiary care center equipped and ready to attend to their needs. Major conduction block, particularly continuous lumbar epidural analgesia, is an ideal form of analgesia for the delivery of most premature neonates. Properly administered, it maintains maternal physiology, is not associated with drug depression in the newborn, enables a controlled, atraumatic vaginal delivery, and has little interaction with tocolytics (and indeed may protect against some of their side effects). It is ideal for a trial of labor and, if initiated early, allows for an emergency cesarean section. Continuous lumbar epidural block and subarachnoid block are both superb for elective or urgent cesarean section. However, when their use is contraindicated, inhalation analgesia for vaginal delivery or general anesthesia for cesarean section can be safely administered from the standpoint of both mother and child. Expertly administered anesthesia is not a luxury but is indeed indispensable for successful premature delivery.

Prophylactic extradural blood patch is effective. A preliminary communication.

Ten obstetric patients received 17-20 ml of autologous blood through an extradural catheter after inadvertent dural puncture. The time interval from dural puncture to prophylactic extradural blood patch ranged from 90 to 660 min. One of the 10 patients developed a mild occipital headache, which required no further intervention.

Term human fetal umbilical vein oxygen content, placental weight, and maternal blood pressure.

The relationship of umbilical venous oxygen content to placental weight and mean maternal arterial blood pressure was investigated in 38 normal nonlaboring subjects undergoing elective cesarean section at 38.4 +/- 0.2 weeks (mean +/- SEM). In 14 subjects breathing room air, umbilical vein oxygen content was found to be a function of the lowest mean maternal arterial blood pressure (r = 0.48, P = 0.04), but not to placental weight. In 24 subjects breathing supplemental oxygen, umbilical vein oxygen content was not related to placental weight or lowest mean maternal arterial blood pressure. Fetuses attached to placentas less than 396 g had a higher hemoglobin concentration than fetuses attached to placentas greater than 396 g. This suggests the possibility of chronic in utero hypoxemia in human fetuses attached to small placentas.

Succinylcholine pharmacodynamics in peripartum patients.

Serum cholinesterase activity decreases 30% during pregnancy and remains depressed during the postpartum period. However, succinylcholine recovery is not prolonged in term-pregnant patients. This contrasts with results obtained in other patients with decreased serum cholinesterase activity. To better understand this paradox, the authors compared serum cholinesterase activity and recovery from succinylcholine, 1 mg/kg, in nonpregnant (with and without oral contraceptive use), in term-pregnant, and in postpartum patients. Serum cholinesterase activity was lower in both term-pregnant (3.66 +/- 0.39 U/ml, means +/- SE) and postpartum (2.84 +/- 0.35 U/ml) patients than in nonpregnant patients not taking oral contraceptives (5.01 +/- 0.33 U/ml, P less than 0.05). Cholinesterase activity in postpartum patients also was significantly lower than in nonpregnant patients taking oral contraceptives (4.81 +/- 0.63, P less than 0.05). In contrast, the time to 25% twitch-height recovery did not differ between term-pregnant (470 +/- 56 s) and nonpregnant patients taking (499 +/- 29 s) or not taking (501 +/- 21 s) oral contraceptives, but was significantly increased in postpartum patients (685 +/- 22 s, P less than 0.001). The similar duration of action of succinylcholine in term-pregnant patients (with decreased serum cholinesterase activities) and nonpregnant patients may be related to the increased volume of distribution of succinylcholine at term.

Estimation of human fetal-placental unit metabolic rate by application of the Bohr principle.

The Bohr Principle via continuous indirect calorimetry was used to estimate human fetal-placental unit metabolic rate in 12 normal women undergoing elective caesarean section under continuous lumbar epidural anaesthesia. Maternal oxygen consumption decreased after umbilical cord clamping and after placental removal. Fetal-placental unit oxygen consumption was 10.7 +/- 1.3 ml/min per kg (mean +/- SEM). Fetal oxygen consumption was 6.8 +/- 1.4 ml/min per kg. Placental oxygen consumption was 37 +/- 12 ml/min per kg. Fetal-placental unit carbon dioxide production was 9.2 +/- 1.2 ml/min per kg. These mean values agree favourably with measurements of uterine and fetal metabolism from other mammalian species. Maternal minute ventilation decreased with removal of the fetal-placental unit, and this decrease was found to be linearly related to the fetal-placental unit carbon dioxide production.