oxytocin and Pruritus

The purpose of this article is to profile research findings targeting the intrapartum care implications of the most common side effects and co-interventions that go along with the use of epidural analgesia during labor. Randomized, controlled trials published in English from 1990 to 2000 that addressed each of the targeted side effects and 3 specified co-interventions were evaluated for inclusion in this report. Side effects such as pruritus, nausea, and hypotension during labor are common, but they are usually mild and necessitate treatment infrequently. However, even with the advent of newer low-dose epidurals, the extent of impaired motor ability remains variable across studies. The incidence of "walking" epidurals during labor is likely to be complicated by multiple factors, including individual patient desires, safety considerations, and hospital policies. In response to risks for a decrease in uterine contractions that could prolong labor, oxytocin augmentation is likely to be administered after epidural analgesia. The use of "delayed" pushing may be an effective way to minimize the risk for difficult deliveries. Upright positioning even when confined to bed may be advantageous and desirable to women; however, additional research to determine actual outcome benefits with epidurals is needed. Implications for further research linked to epidural analgesia also include informed consent, modification of caregiving procedures, and staffing/cost issues.

Topics: Analgesia, Epidural; Analgesia, Obstetrical; Female; Humans; Hypotension; Motor Activity; Oxytocin; Pregnancy; Pruritus; Shivering; Urinary Retention

Placebo effects relieve various somatic symptoms, but it is unclear how they can be enhanced to maximize positive treatment outcomes. Oxytocin administration may potentially enhance placebo effects, but few studies have been performed, and they have had conflicting findings. The study aim was to investigate the influence of positive verbal suggestions and oxytocin on treatment expectations and placebo effects for pain and itch.. One hundred eight female participants were allocated to one of the following four groups: (1) oxytocin with positive verbal suggestions, (2) placebo with positive verbal suggestions, (3) oxytocin without suggestions, and (4) placebo without suggestions. The administration of 24 IU oxytocin or a placebo spray was preceded by positive verbal suggestions regarding the pain- and itch-relieving properties of the spray or no suggestions, depending on group allocation. Pain was assessed with a cold pressor test, and itch was assessed with histamine iontophoresis.. Positive verbal suggestions induced expectations of lower pain (F = 4.77, p = .031) and itch (F = 5.38, p = .022). Moreover, positive verbal suggestions elicited placebo analgesia (F = 5.48, p = .021) but did not decrease itch. No effect of oxytocin on the placebo effect or on expectations was found.. Positive suggestions induced placebo analgesia but oxytocin did not enhance the placebo effect. Study limitations are that we only included a female sample and a failure to induce placebo effect for itch. Future studies should focus on how oxytocin might influence placebo effects, taken into account the role of sex, dose-dependent effects, and various expectation manipulations.. The study was registered as a clinical trial on www.trialregister.nl (number 6376).

Topics: Adult; Analgesia; Female; Humans; Oxytocin; Pain; Placebo Effect; Pruritus; Suggestion; Treatment Outcome; Young Adult

To test the hypothesis that patient-controlled epidural analgesia (PCEA) using ropivacaine and fentanyl provides better maternal satisfaction and less anesthetic requirement than conventional continuous epidural infusion (CEI) during labor, we studied 58 uncomplicated parturients (singleton, vertex presentation).. After establishing effective epidural analgesia with 11 ml of 0.2% ropivacaine, all parturients were randomly divided into one of two groups: the PCEA group (n = 29) or the CEI group (n = 29). In the PCEA group, the pump was initiated to deliver a basal infusion at 6 ml x h(-1) and a demand dose of 5 ml; the lockout interval was 10 min, and there was a 31 ml x h(-1) limit. The drugs used were 0.1% ropivacaine + fentanyl 2 microg x ml(-1). In the CEI group, epidural analgesia was maintained with the same solution as the PCEA group at a constant rate of 10 ml x h(-1). If parturients requested additional analgesia in the CEI group, we added 8 ml of epidural 0.2% ropivacaine without fentanyl.. Parturients' demographic data, such as duration of labor, mode of delivery, Apgar score, and umbilical arterial pH did not differ between the two groups. However, the hourly requirement of ropivacaine was significantly less in the PCEA group than in the CEI group (9.3 +/- 2.5 vs. 17.6 +/- 7.6 mg x h(-1); P < 0.05). Parturients' satisfaction assessed by the Visual Analogue Scale tended to be higher in the PCEA group than in the CEI group. Side effects such as nausea, hypotension, and itching were similar for the two groups.. We found that PCEA was an effective means of providing optimal analgesia, with better satisfaction during labor and less local anesthetic requirement.

Topics: Adult; Amides; Analgesia, Epidural; Analgesia, Obstetrical; Analgesia, Patient-Controlled; Anesthetics, Intravenous; Anesthetics, Local; Female; Fentanyl; Humans; Oxytocics; Oxytocin; Pain Measurement; Patient Satisfaction; Pregnancy; Pruritus; Ropivacaine

The purpose of this randomized, double blinded and controlled study was to determine the optimal dose of intrathecal fentanyl when combined with bupivacaine 2.5 mg for initiation of labor analgesia. Parous parturients with cervical dilation between 3 and 5 cm were randomized to receive intrathecal fentanyl 0 (control), 5, 10, 15, 20 or 25 micrograms, combined with bupivacaine 2.5 mg, followed by a lidocaine/epinephrine epidural test dose. Visual analog pain scores (VAPS) and the presence of side effects were determined every 15 min until the parturient requested additional analgesia. Fetal heart rate (FHR) tracings were compared between groups. All parturients who received fentanyl >/= 15 micrograms had VAPS < 20 mm and duration of analgesia > 15 min, but this was not true for all parturients with fentanyl doses < 15 micrograms. Duration of analgesia was shorter for fentanyl groups 0, 5 and 10 micrograms, compared to groups 15, 20 and 25 micrograms, but there was no difference between the 15, 20 and 25 micrograms groups. There was no difference in the incidence of nausea and vomiting, or in FHR tracing changes. The incidence of pruritus was greater in all fentanyl groups compared to control. These data suggest that, when combined with intrathecal bupivacaine 2.5 mg, fentanyl 15 micrograms provides satisfactory analgesia to all parturients. Higher fentanyl doses produced no additional benefit in duration or quality of analgesia.

Topics: Adult; Analgesia, Obstetrical; Analgesics, Opioid; Anesthetics, Local; Bupivacaine; Dose-Response Relationship, Drug; Double-Blind Method; Female; Fentanyl; Heart Rate, Fetal; Humans; Injections, Spinal; Oxytocin; Pain Measurement; Postoperative Nausea and Vomiting; Pregnancy; Pruritus

To determine the efficacy and safety of intradural-epidural analgesia in comparison with continuous epidural analgesia during labor and childbirth.. Forty-two women whose labor began spontaneously were enrolled and distributed randomly in two groups. The intradural-epidural analgesia group (IEA, n = 21) received 25 microgram of intradural fentanyl with 2.5 mg of isobaric bupivacaine with adrenalin, after which analgesia was maintained with epidural administration of one 8 mL bolus of 0.125% bupivacaine, followed by perfusion of a balanced concentration at a rate of 8 ml/h. Patients in the continuous epidural analgesia group (CEA, n = 21) were given 8 ml of 0.25% bupivacaine with adrenalin; the epidural perfusion of 0.125% bupivacaine and 1 microgram/ml of fentanyl was started at the same rate as in the IEA group. We recorded pain as assessed on a visual analog scale, extension of sensory and motor block, maternal hemodynamic constants, number of boluses of bupivacaine used, total doses of bupivacaine and oxytocin, instruments needed for childbirth, and side effects (pruritus, nausea and vomiting).. Analgesic efficacy during the first 30 minutes was greater in the IEA group. The total dose of bupivacaine, required top-up boluses, and the extension of sensory block at 30 minutes, one hour and two hours were also significantly less in the IEA group. The incidence of pruritus was higher in the IEA group. No significant differences were observed for other variables.. Intradural-epidural analgesia provides effective analgesia for labor, with rapid onset, reduced extension of sensory block, lower total doses of local anesthetics and few side effects.

Topics: Adult; Analgesia, Epidural; Analgesia, Obstetrical; Anesthesia Recovery Period; Bupivacaine; Cesarean Section; Epinephrine; Female; Fentanyl; Humans; Hypotension; Infant, Newborn; Labor, Obstetric; Nausea; Oxytocin; Patient Acceptance of Health Care; Pregnancy; Prospective Studies; Pruritus; Safety; Single-Blind Method; Vomiting

Intrathecal injection of morphine was used to provide obstetric analgesia in 20 primiparous women in labor. When the cervix was at least 3 cm dilated, morphine, 1 or 2 mg, was injected intrathecally. In all parturients, labor pains were completely relieved after 15-60 min and analgesia lasted as long as eight to 11 hours. The analgesia was not associated with any alteration of pin-prick sensation or motor power, and there was no change in the arterial blood pressure or heart rate. All infants were delivered vaginally by use of episiotomy annd a low forceps, except two infants of mothers in the 2 mg of morphine group who needed cesarean section. During the second stage of labor, analgesia was supplemented by lidocaine, 2 per cent, using local perineal infiltration in 14 parturients and pudendal block in two parturients, and by epidural block in four parturients. Nineteen of the 20 newborns cried immediately at birth, and had Apgar scores o 7-9 at 1 min and 8-10 at 5 min. During the first 24 hours of life, the neurobehavioral responses of all newborns were scored as normal. Systemic maternal side effects such as somnolence, nausea, vomiting, and itching occurred in a high proportion of the parturients. However, in the majority of cases, these side effects were mild. Only two parturients of the 2 mg morphine group complained of marked somnolence, itching, and vomiting, which persisted post partum; these were effectively reversed by the specific antagonist naloxone. The analgesic effect of intrathecal morphine can be attributed to its action on the opiate receptors in the substantia gelatinosa of the dorsal horn of the spinal cord. However, supraspinal effects of morphine cannot be excluded. The low lipid solubility of morphine can explain its slow onset and prolonged duration of action. Also, this will result in minimal systemic absorption of morphine, which protects the fetus and results in selective maternal analgesia.

Topics: Adolescent; Adult; Anesthesia, Obstetrical; Clinical Trials as Topic; Dose-Response Relationship, Drug; Female; Humans; Injections, Spinal; Morphine; Nausea; Oxytocin; Parity; Pregnancy; Pruritus; Uterine Contraction; Vomiting

Oxytocin (OXT) is secreted in a large amount during the middle and late pregnancy. Except for the regulation of functions related to childbirth, OXT is involved in the regulation of cognition, social behavior, addiction, pain and so on. Our aim is to confirm the increase of OXT content in mice in late pregnancy is the main cause of itch during pregnancy and observe whether exogenously administered OXT can induce or increase itch sensitivity. The research shows that itch sensitivity of mice increased significantly in late pregnancy and basically returned to normal one day after delivery. The number of OXT-positive neurons in paraventricular nucleus (PVN) and the content of OXT in serum of the late pregnant mice increased significantly, and decreased sharply after delivery. Intradermal injection of low concentration of OXT (0.2 nmol/L) could not induce scratching behavior in mice, but high concentration of OXT (5 nmol/L, 10 nmol/L) could do this in a dose-dependent manner. Low concentration of OXT significantly increased the itch sensitivity to histamine. Intradermal injection of oxytocin receptor (OXTR) or arginine vasopressin-1a receptor (AVPR1A) antagonist did not affect histamine-induced scratching behavior, but both reversed the increase of itch sensitivity in late pregnant mice or the facilitated itch sensitivity by OXT. Study suggests that both endogenous and exogenous increases in OXT can increase the body's sensitivity to itch, and even induce itch directly. Pruritus during pregnancy is closely related to the increase of OXT content in vivo. In the periphery, the itch-promoting effect of OXT is mediated by OXTR and AVPR1A.

Topics: Animals; Female; Histamine; Mice; Oxytocin; Pregnancy; Pruritus; Receptors, Oxytocin; Receptors, Vasopressin

Anatomic, physiologic, and behavioral studies in animals suggest that spinally released oxytocin should produce analgesia in humans and may also protect from chronic pain after injury. In this article, the authors report preclinical toxicity screening of oxytocin for intrathecal delivery.. Intrathecal oxytocin, 11 μg (6 U) or vehicle, was injected intrathecally in 24 rats, followed by frequent behavioral assessment and histologic examination of spinal contents 2 or 14 days after injection. In three dogs, a range of intrathecal oxytocin doses (18 to 550 μg in 0.5 ml) was injected followed by physiologic, biochemical, and behavioral assessments. Ten dogs were then randomized to receive five daily injections of intrathecal oxytocin, 550 μg in 0.5 ml, or vehicle with similar assessments and, necropsy and histologic analysis were conducted 2 days later.. In rats, intrathecal oxytocin resulted in transient scratching and itching behaviors, without other differences from vehicle. There was no behavioral, gross anatomic, or histologic evidence of neurotoxicity. Dose ranging in dogs suggested mild effects on motor tone, blood pressure, and heart rate at the 550 μg dose. Repeated boluses in dogs did not produce behavioral, biochemical, neurological, gross anatomic, or histologic evidence of neurotoxicity.. Substances, including natural neurotransmitters, may be toxic when administered in pharmacologic doses in the spinal cord. This preclinical toxicity screen in two species suggests that bolus injections of oxytocin in concentrations up to 1,100 μg/ml are unlikely to cause neurotoxicity. The authors also support cautious clinical application of intrathecal oxytocin under regulatory supervision.

Topics: Animals; Behavior, Animal; Blood Pressure; Dogs; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Evaluation, Preclinical; Female; Follow-Up Studies; Heart Rate; Injections, Spinal; Male; Oxytocics; Oxytocin; Pruritus; Random Allocation; Rats; Rats, Sprague-Dawley; Toxicity Tests, Acute; Toxicity Tests, Chronic