Term Parturients Research Articles

In Vitro Effects of Propofol on Gravid Human Myometrium

The aim of this study was to evaluate the direct effect of propofol (di-isopropyl phenol) on the contractile properties of gravid human uterine muscle. Six specimens of uterine muscle were obtained from term parturients undergoing elective lower segment caesarean section. Small strips (1 x 2 x 12 mm) of muscle were prepared and suspended in an organ bath containing oxygenated Kreb's solution at 36.5 degrees C. Following preparation, spontaneous regular contractions developed at a rate of one contraction every six to 10 minutes. Force of contraction was recorded continuously using an isometric tension transducer Following baseline measurements, propofol was introduced into the bath at concentrations corresponding to 2 microg/ml, 5 mcirog/ml and 8 mirog/ml. The specimens were also exposed to intralipid in concentrations equivalent to that found in the 8 microg/ml solution of propofol to determine whether this additive influenced uterine contractility. Contractility (defined as area under the tension/time curve) was decreased to 89 +/- 6.5% of control at 2 microg/ml, 53 +/- 4.3% at 5 microg/ml and 45 +/- 4.1% at 8 microg/ml. This decrease in contractility was statistically significant at concentrations >2 microg/ml. Intralipid did not significantly affect uterine contractility. The results of this study show that propofol decreases isolated human uterine muscle contractility in a dose-dependent manner

Étude de l’immunité antitétanique chez les femmes enceintes durant l’année 2007 au service de maternité Souissi de Rabat

Summary The prevention against tetanus has considerably improved in the world. The eradication of neonatal tetanus is the one of the main aim of the WHO program. Even though the administration of tetanus toxoid has resulted in a decrease of the cases of tetanus in major industrialized countries, the situation in many developing countries is still alarming. In order to assess the impact of antitetanus vaccination, a prospective study was conducted from January 2007 to April 2007 in the emergency department of motherhood of Souissi for the assessment of the immune status of term parturient. We used immunochromatographic test for the detection of antitetanic antibodies. The results showed that 62% of cases (99 women) were immunized for tetanus, and 38% of the cases (61 women) were not. The strengthening of the immune status by the administration of booster doses of tetanus vaccine to teenagers and women of childbearing potential will enable the eradication of tetanus.

Effects of Normobaric Hyperoxia on Hemodynamic Parameters of Healthy Full-term Parturients

Litchfield, K.N.; Harten, J.M.; Anderson, K.J.; Kinsella, J.; McGrady, E.M. Author Information

Frequency of electrocardiographic changes indicating myocardial ischemia during elective cesarean delivery with regional and general anesthesia: detection based on continuous Holter monitoring and serum markers of ischemia

Study ObjectiveTo determine the frequency of electrocardiographic (ECG) changes and to assess the occurrence of myocardial ischemia during elective cesarean delivery with either regional or general anesthesia. DesignRandomized, prospective, single-blinded clinical trial. SettingLarge referral hospital. Patients40 ASA physical status I and II term parturients. InterventionsPatients were divided randomly into two groups as follows: the regional anesthesia group (group 1, n = 20) and the general anesthesia group (group 2, n = 20). MeasurementsIn each case, continuous ECG was done using a 7-lead Holter monitor in the operating room, continuing for 24 hours after surgery. All Holter traces were analyzed by a study-blinded cardiologist. Blood samples were collected preoperatively (baseline) and at one, 5, and 24 hours postoperatively. Serum troponin T, creatinine kinase-MB, and myoglobin levels were measured. Main ResultsTwo patients in group 1 (10%) and one patient in group 2 (5%) showed one mm ST-segment depression for two to 5 minutes. In all 40 cases, troponin T levels were in the normal range at all time points studied. In both groups, mean serum creatinine kinase-MB and myoglobin levels at one and 5 hours postoperatively were significantly higher than at baseline (P < 0.05). These high CK-MB and myoglobin levels were returned to normal ranges at the end of the study period; none of these women showed ST-segment changes. ConclusionThe ST-segment changes are not frequent in healthy women undergoing elective cesarean delivery during either regional or general anesthesia, and we found no evidence of myocardial injury.

Pre‐oxygenation in pregnancy: the effect of fresh gas flow rates within a circle breathing system*

We have investigated the effect of oxygen flow rate on pre-oxygenation in pregnant patients at term using a circle system. Twenty patients presenting for elective Caesarean section maintained tidal volume breathing through a standard circle system for 3 min. Subjects were pre-oxygenated using oxygen flow rates of 5 l.min(-1), 10 l.min(-1) and 15 l.min(-1) presented in random order. The mean (SD) fractional end-tidal oxygen at the end of 3 min was 0.86 (0.07) for 5 l.min(-1), 0.92 (0.05) for 10 l.min(-1)and 0.90 (0.09) for 15 l.min(-1) (p < 0.001). Entrainment of air occurred in 22% of pre-oxygenation sessions. Oxygen flow rates of 10 l.min(-1) or above provide optimal pre-oxygenation using a circle system in term parturients. In our study, entrainment of air occurred in a surprisingly high percentage of cases.

PAIN RELIEF AND SIDE EFFECTS IN INTRAVENOUS REMIFENTANIL AND IINTRAMUSCULAR MEPERIDINE

Introduction: Although there no agreement about best way for relieving pain in delivery, finding an appropriate method with the lowest pain and drug dose and side effect shoud be considered. The aim of this study is to compare the analgesic efficacy and side effects of Remifentanil and Meperidine as two methods of pain relieving in obstetrics during an uncomplicated labor. Materials and Methods: Fourty full term parturient with singleton pregnancy and vertex presentation were randomized to receive either Remifentanil (0.5µg/kg every 4 min, IV) or Meperidine (50 mg, IM) at the beginning of active labor phase. A visual analog scale (VAS) was used to assess the severity of pain. Also maternal and fetal side effects were assessed. Results: The pain scores were lower in Remifentanil group at 60 min after analgesia (P<0.0001) and during the first stage of labor (P<0.0001) than Meperidine group. The pain scores in second stage of labor were also lower in Remifentanil group (P=0/013). 95% of women rated analgesia as good to excellent in Remifentanil group as compared with 35% in Meperidine group (P<0.0001). Prolonged labor in first stage was rare in the both groups and there were no significant differences between them. Side effects such as sedation, nausea and vomiting and respiratory depression and decreasing hemoglobin oxygen and saturation were rare and no significant differences were seen between groups. Also no significant differences were seen between groups from mode of delivery or neonatal outcomes. Conclusion: The results indicated that for controlling delivery pains Remifentanil is better than Meperidine and side effects were uncommon and adequate continuous monitoring decrease maternal side effects.

Intrathecal morphine in anesthesia for cesarean delivery: dose-response relationship for combinations of low-dose intrathecal morphine and spinal bupivacaine

Study objective To evaluate the quality of analgesia and the severity of side effects of intrathecal morphine administered for a dose range of 0.0 to 0.4 mg for postcesarean analgesia with low-dose bupivacaine. Design Double-blind, randomized study. Setting University hospital. Patients 100 ASA physical status I and II term parturients undergoing cesarean delivery with spinal anesthesia in the operating room. Interventions Patients were randomized to one of 5 groups to receive 0.0, 0.1, 0.2, 0.3, or 0.4 mg intrathecal morphine in addition to low-dose (7.5 mg) heavy bupivacaine. Each patient received intravenous (IV) patient-controlled analgesia (PCA) with morphine after the operation. Measurements 24-hour IV PCA morphine use and visual analog scores for pain were recorded. The severity score (4-point scale) of nausea, vomiting, and pruritus were assessed intraoperatively and at 4-hour intervals during the first 24 hours postoperatively. Main results PCA morphine use was higher in the control group (0.0 mg) than in groups receiving 0.1, 0.2, 0.3, or 0.4 mg intrathecal morphine. There was no difference in IV PCA morphine use between the 0.1 and 0.4-mg groups, despite a 4-fold increase in intrathecal morphine dose. There was no difference between groups in nausea and vomiting, but pruritus increased in direct proportion to the dose of intrathecal morphine (linear regression, P = 0.0001). Conclusions The dose of 0.1 mg intrathecal morphine produces analgesia comparable with doses as high as 0.4 mg, with significantly less pruritus when combined with low-dose bupivacaine.

¿Es realmente necesaria y útil la oxigenoterapia suplementaria en la cesárea programada bajo anestesia subaracnoidea?

To analyze maternal and fetal well-being with and without the application of oxygen therapy. Randomized trial of full-term parturients who had received prenatal care during pregnancy. The women were healthy and classified as ASA 1. They were scheduled for delivery by cesarean section under spinal anesthesia and randomized to 2 groups to breathe room air or air providing an inspired oxygen fraction of 40% through a face mask. We assessed the well-being of the neonate immediately after birth with the Apgar test and by measuring umbilical cord blood gases. One hundred thirty women were enrolled. Both groups were similar, with no differences in demographic or hemodynamic variables, time from uterine incision to fetal extraction, neonatal birth weight, presence of umbilical cord abnormalities, type of resuscitation required by the neonate, or Apgar score in the first or fifth minute. Oxygen saturation in maternal blood by pulse oximetry was higher after 10 minutes in the group of women who received supplemental oxygen through face masks. We also observed significant differences in umbilical cord arterial blood between the room air and supplemental oxygen groups, respectively, as follows: PaCO2, 51.14 mm Hg vs 54.33 mm Hg (P=.016); bicarbonate, 22.19 mEq L(-1) vs 23.23 mEq L(-1) (P=.012); lactate, 1.85 mmol L(-1) vs 1.64 mmol L(-1) (P=.038). The PO2 in venous blood also differed significantly: 25.53 mm Hg vs 28.13 mm Hg, respectively (P=033). Breathing supplemental oxygen or not during elective cesarean delivery of healthy parturients under spinal anesthesia does not have a significant effect on neonatal well-being.

208: The efffect of histologic chorioamnionitis on risk factors for intrapartum fever in the term parturient

208: The efffect of histologic chorioamnionitis on risk factors for intrapartum fever in the term parturient

205: Evaluation of clinical signs for diagnosing histologic acute chorioamnionitis in the term parturient

Using histologic chorioamnionitis as the gold standard, the goal was to estimate the sensitivity, specificity, and predictive values of clinical signs in the diagnosis of acute chorioamnionitis in the placenta.

206: Histologic classification of acute chorioamnionitis in the term parturient

206: Histologic classification of acute chorioamnionitis in the term parturient

Comparing the Airtraq® with the LMA CTrach ™

University of Washington, Seattle, Washington. agoldman@u.washington.eduI read with great interest the case report by Dhonneur et al. 1using the Airtraq® (King Systems, Noblesville, IN) optical laryngoscope after failed direct laryngoscopy in two patients requiring emergency cesarean delivery. Placing an Airtraq® (or any of the new video-laryngoscopes, e.g. , GlideScope®[Verathon, Bothell, WA], McGrath®[LMA North America, San Diego, CA]) as a brief plan B after a failed direct laryngoscopy in obstetrics may be an evolving new standard of practice for an emergency cesarean delivery. However, comparing the Airtraq® intubation time with the LMA CTrach ™ (LMA North America, San Diego, CA) intubation time (<1 min vs. 3 min) is not an entirely appropriate comparison.1The CTrach time of 3 min includes establishing ventilation and removing the CTrach airway after intubation is confirmed.2The ventilatory capacity of the CTrach is arguably equally important to its effectiveness as an intubation conduit during airway resuscitation.3It is well known how quickly a term parturient can desaturate during laryngoscopy. The CTrach (like the intubating laryngeal mask airway) is an effective ventilatory device with ventilatory success rates of greater than 99%.2,4If intubation is not successful, the presence of an effective airway can be lifesaving. The CTrach gives the operator time to optimize the laryngeal view and the patient's physiologic parameters before attempting intubation.3,5Liu et al. 2report a 99% first-pass intubation success in the 84% of patients whose larynx was seen on the CTrach monitor. In the remaining 16%, the CTrach functioned as an intubating laryngeal mask airway would, with corresponding intubation/ventilation success rates. Ventilation and oxygenation, not solely intubation, are the primary goals of effective airway resuscitation.University of Washington, Seattle, Washington. agoldman@u.washington.edu

Effects of normobaric hyperoxia on haemodynamic parameters of healthy full‐term parturients

Fifteen healthy, full-term women with singleton pregnancies were exposed to an increased F(I)o(2) of 0.4 and their haemodynamic responses measured with a non-invasive transthoracic bio-impedance monitor. There was a mean reduction in cardiac index from 3.18 to 3.03 l x min(-1) x m(-2) (4.7%, p = 0.004). The mean indexed systemic vascular resistance increased from 2049 to 2178 dynes x cm(-5) x m(-2) (5.7%, p = 0.005). There were no significant changes in stroke index, heart rate or mean arterial pressure. This study demonstrates that even a moderate increase in inspired oxygen fraction has significant effects on the cardiovascular system of the term parturient.

Remifentanil patient-controlled analgesia for labour: optimizing drug delivery regimens.

A pilot study was undertaken to compare the efficacy of two regimens of intravenous patient-controlled analgesia (PCA) with remifentanil for labour analgesia. Twenty term parturients requesting labour analgesia were randomized to receive one of two regimens of intravenous remifentanil. The initial settings in both groups consisted of an infusion of 0.025 μg·kg-1·min-1, a PCA bolus of 0.25 μg·kg-1 and a lockout interval of two minutes. In Group A, the infusion was increased in a stepwise manner from 0.025 to 0.05, 0.075 and 0.1 μg·kg-1·min-1 as required; the bolus was kept constant at 0.25 μg·kg-1. In Group B, the bolus was increased from 0.25 to 0.5, 0.75 and 1 μg·kg-1 as necessary; the infusion was kept constant at 0.025 μg·kg-1·min-1. Maternal pain, satisfaction and sedation scores, remifentanil requirement, and side effects were recorded. Mean pain and patient satisfaction scores, and cumulative doses of remifentanil were similar in the two groups. The overall incidence of side effects was greater in Group B (P = 0.0007), with drowsiness observed in 100% of patients, as compared to 30% in Group A (P = 0.003). The minimum oxygen saturation levels were 94.3% ± 2.6% and 92.2% ± 3.8% in Groups A and B respectively (P = 0.19). Although pain and satisfaction scores were similar in both groups, the regimen used in Group A was associated with fewer side effects compared to the Group B dosing regimen. This pilot study suggests that remifentanil intravenous PCA is efficacious for labour analgesia as a bolus of 0.25 μg·kg-1, with a lockout interval of two minutes and continuous infusion of 0.025-0.1 μg·kg-1·min-1. The potential for respiratory depression mandates close respiratory monitoring. Large-scale trials to evaluate safety issues are warranted.

Small dose spinal bupivacaine for Cesarean delivery does not reduce hypotension but accelerates motor recovery

Maternal hypotension occurs in 60-94% of Cesarean deliveries with 10-15 mg spinal bupivacaine. Reduced doses of bupivacaine may decrease the incidence of hypotension, nausea, and vasopressor use. The primary objective of this study was to compare 4.5 mg and 12 mg doses of intrathecal bupivacaine on maternal hemodynamics. The secondary objective was to determine if anticipated reductions in side effects were reflected in increased patient satisfaction. Following Research Ethics Board approval and informed consent 52 term parturients undergoing elective Cesarean delivery were randomly assigned to isobaric bupivacaine 4.5 mg or hyperbaric bupivacaine 12 mg for spinal anesthesia. All patients received fentanyl 50 microg and morphine 200 microg intrathecally. Intravenous fluid and vasopressor administration were standardized. Maternal hemodynamics, and sensorimotor levels were recorded at regular intervals. Side effects and patient satisfaction were documented. Median cepahalad sensory block was C8 in both groups (NS) but the intensity of motor block was significantly less (P < 0.001) and of shorter duration (P < 0.001) with bupivacaine 4.5 mg. The proportion of patients requiring ephedrine (> 70%) and the quantities of ephedrine used were similar in both groups (NS). Use of supplemental analgesia, side effects, and measures of patient satisfaction were comparable in both groups. Intrathecal bupivacaine 4.5 and 12 mg yielded similar sensory block and side effects during Cesarean delivery. Patients receiving 4.5 mg did, however, experience significantly less motor blockade of shorter duration.

Determination of the Full Dose–Response Relation of Intrathecal Bupivacaine, Levobupivacaine, and Ropivacaine, Combined with Sufentanil, for Labor Analgesia

Ropivacaine and levobupivacaine are local anesthetics that produce less motor block and greater sensory-motor separation when compared with equal milligram doses of bupivacaine. Although minimum local analgesic concentration studies suggested that they are less potent than bupivacaine, full dose-response studies have not been performed. The current trial describes the dose-response relation of levobupivacaine, ropivacaine, and bupivacaine, combined with sufentanil, when used for intrathecal labor analgesia. Four hundred fifty term parturients in active labor were included in this double-blind, randomized trial. Combined spinal-epidural anesthesia was performed, and ropivacaine, levobupivacaine, or bupivacaine was intrathecally administered in a dose of 1.0, 1.5, 2.0, 2.5, 3.0, or 3.5 mg, always combined with 1.5 microg sufentanil. Patients were considered responders to spinal analgesia if the visual analog scale score for pain was less than 25 mm within 15 min and the visual analog scale score remained less than 25 mm for 45 min. Patient demographics, obstetric data, maternal side effects, and fetal and neonatal well-being were noted. Group-specific dose-response curves were constructed using a probit regression model. The ED95 of bupivacaine was 3.3 mg (95% confidence interval, 2.9-4.1). The ED95s of ropivacaine and levobupivacaine were 4.8 mg (95% confidence interval, 4.0-6.7) and 5.0 mg (95% confidence interval, 4.1-7.0), respectively. Racemic bupivacaine was significantly more potent than ropivacaine (P=0.0027) and levobupivacaine (P=0.0006). Ropivacaine and levobupivacaine were of similar potency (P=0.91). This full dose-response study suggests that ropivacaine and levobupivacaine are of similar potency, whereas bupivacaine is more potent than both other drugs.

Pain relief by applying transcutaneous electrical nerve stimulation (TENS) on acupuncture points during the first stage of labor: A randomized double-blind placebo-controlled trial

Transcutaneous electrical nerve stimulation (TENS) is one of the non-pharmacological means of pain relief for labor and delivery. We aimed to investigate the efficacy and safety of TENS on specific acupuncture points for reducing pain in the first stage of labor. In this double-blind, placebo-controlled trial, we randomly assigned healthy full-term parturients in active phase of first-stage labor to either TENS on four acupuncture points (Hegu [Li 4] and Sanyinjiao [Sp 6]) ( n = 52) or the TENS placebo ( n = 53). Visual analogue scale (VAS) was used to assess pain before and 30 and 60 min after treatment. The primary outcome was the rate of VAS score decrease ⩾3 in each group. A questionnaire was given at 24 h post-partum to evaluate the satisfaction of pain relieving method and the willingness to have the same treatment again. Mode of delivery and neonatal effect were measured as secondary outcome. One hundred women were eligible for analysis. TENS group experienced VAS score reduction ⩾3 significantly more common than the TENS placebo group (31/50 [62%] vs 7/50 [14%], P < 0.001). Willingness of using the same analgesic method for a future childbirth was also significantly different (TENS: 48/50 [96%] vs TENS placebo: 33/50 [66%], P < 0.001). Operative delivery was increased in the TENS group (12/50 [24%] vs 4/50 [8%], P = 0.05), but the neonatal outcomes were not different. The application of TENS on specific acupuncture points could be a non-invasive adjunct for pain relief in the first stage of labor.

Levobupivacaine-Sufentanil With or Without Epinephrine During Epidural Labor Analgesia

In a prospective, randomized, double-blind study, we investigated whether epinephrine increased the efficacy of levobupivacaine and sufentanil during epidural labor analgesia. Seventy term parturients received an epidural injection of levobupivacaine 0.125% and sufentanil 0.75 microg/mL with or without 1:800,000 epinephrine. After an initial dose of 10 mL, a patient-controlled analgesia pump was started. Total and hourly drug consumption, pain scores using the visual analog scale, sensory and motor block, duration of labor, vital variables, maternal and neonatal outcome, and side effects were compared. If the parturients experienced insufficient pain relief during the study, even after a rescue dose of 10 mL, they were excluded from further study and received 10 mL of bupivacaine 0.125% and sufentanil 0.75 microg/mL with 1:800,000 epinephrine. Hourly drug consumption, rescue dosing, and pain scores at 15 min and 20 min were lower in the epinephrine group. The incidence of motor block and duration of the second stage of labor tended to be higher in the epinephrine group and were associated with lower Apgar scores at 1 and 5 min. These findings suggest that the addition of epinephrine intensifies the effects of epidural levobupivacaine and sufentanil but may cause more motor block.

Circulating Mature Adrenomedullin Is Related to Blood Volume in Full-Term Pregnancy

Plasma adrenomedullin concentration increases during pregnancy. We measured blood volume and mature adrenomedullin concentration in plasma and cerebrospinal fluid and examined whether mature adrenomedullin in plasma and cerebrospinal fluid was associated with increasing blood volume during pregnancy. We enrolled 47 women undergoing surgery with spinal anesthesia in this study. We first measured mature adrenomedullin concentration in plasma and cerebrospinal fluid of nonpregnant women undergoing orthopedic surgery, pregnant women between 15 and 18 wk of gestation undergoing gynecological surgery, and pregnant women at full-term undergoing cesarean delivery. The second study included 20 healthy and full-term parturients scheduled for cesarean delivery. We measured arterial blood pressure and blood volume by noninvasive pulse spectrophotometry using indocyanine green. Plasma-mature adrenomedullin concentration was 1.24 +/- 0.98, 2.79 +/- 1.23, 4.79 +/- 2.61 fmol/mL (mean +/- sd) in the nonpregnant, the early gestation, and the full-term groups, respectively. But in cerebrospinal fluid, mature adrenomedullin did not significantly increase. Furthermore, mature adrenomedullin in plasma, but not cerebrospinal fluid, had a significant correlation with blood volume per unit body weight (r2= 0.46; P = 0.0009). These findings demonstrate that plasma-mature adrenomedullin concentration increased and that increased plasma-mature adrenomedullin is associated with increased blood volume during pregnancy.

Evaluation of the platelet function analyzer (PFA-100®) vs. the thromboelastogram (TEG) in the parturient

The platelet function analyzer (PFA-100) is a bedside test of coagulation designed to evaluate platelet function. It measures the time required for whole blood to occlude a membrane impregnated with either epinephrine (EPI) or adenosine 5'diphosphate (ADP). The results are reported as closure time (CT-EPI or CT-ADP) in seconds. The thromboelastogram (TEG) measures whole blood clotting and the maximum amplitude (MA) correlates with platelet count and function. We wished to establish whether there is a correlation between the CT and platelet count, between the CT and MA, and between the MA and platelet count. Platelet count, CT, and MA were measured in blood drawn from 172 healthy term parturients using the PFA-100. We were unable to detect a significant correlation between the CT-EPI and platelet count (r=-0.1, P=0.21), or the CT-ADP and platelet count (r=-0.02, P=0.83). We also did not find a correlation between the CT-EPI and MA (r=-0.13, P=0.12) or between the CT-ADP and MA (r=-0.11, P=0.19). However, we found a significant correlation between platelet count and MA (r=0.33, P<0.001). We conclude that the CT does not correlate with the platelet count or MA in the parturient, but the TEG does. Therefore the TEG may be a better tool to evaluate coagulation in the parturient with thrombocytopenia.