缩宫素相关文摘-pubmed

缩宫素相关文摘-pubmed 1: Br J Anaesth. 2008 Dec;101(6):822-6. Epub 2008 Oct 9. Intravenous oxytocin bolus of 2 units is superior to 5 units during elective Caesarean section. Sartain JB, Barry JJ, Howat PW, McCormack DI, Bryant M. Department of Anaesthesia, Intensive Care and Perioperative Medicine, Cairns Base Hospital, The Esplanade, Cairns, QLD 4870, Australia. james_sartain@health.qld.gov.au BACKGROUND: The optimal dose of oxytocin at Caesarean section is unclear. Oxytocin may cause adverse cardiovascular effects, including tachycardia and hypotension, whereas an inadequate dose can result in increased uterine bleeding. We compared the effects of two doses of oxytocin in a randomized double-blind trial. METHODS: Eighty patients undergoing elective Caesarean section received an i.v. bolus of either 2 or 5 units (u) of oxytocin after delivery, followed by an oxytocin infusion of 10 u h(-1). All received combined spinal-epidural anaesthesia with arterial pressure maintained by a phenylephrine infusion. We compared changes in heart rate (HR), mean arterial pressure (MAP), blood loss, uterine tone, the need for additional uterotonic drugs, and emetic symptoms. RESULTS: There was a greater increase in mean (sd) HR in patients who received 5 u of oxytocin [32 (17) beats min(-1)] than in those who received 2 u [24 (13) beats min(-1)] (P=0.015). There was a larger decrease in MAP in patients who received 5 u [13 (15) mm Hg] than in those who received 2 u [6 (10) mm Hg] (P=0.030). The frequency of nausea and antiemetic use was higher after 5 u (32.5%) than 2 u (5%) (P=0.003). There were no differences in blood loss, uterine tone, or requests for additional uterotonic drugs (17.5% in both groups). CONCLUSIONS: In elective Caesarean section, a 2 u bolus of oxytocin results in less haemodynamic change than 5 u, with less nausea and no difference in the need for additional uterotonics. Publication Types: Randomized Controlled Trial PMID: 18845650 [PubMed - indexed for MEDLINE] 2: Int J Obstet Anesth. 2008 Jul;17(3):247-54. Epub 2008 May 29. The hemodynamics of oxytocin and other vasoactive agents during neuraxial anesthesia for cesarean delivery: findings in six cases. Archer TL, Knape K, Liles D, Wheeler AS, Carter B. Department of Anesthesiology, University of Texas Health Science Center, San Antonio, Texas 79229, USA. archert@uthscsa.edu Oxytocin is a commonly used uterotonic that can cause significant and even fatal hypotension, particularly when given as a bolus. The resulting hypotension can be produced by a decrease in systemic vascular resistance or cardiac output through a decrease in venous return. Parturients with normal volume status, heart valves and pulmonary vasculature most often respond to this hypotension with a compensatory increase in heart rate and stroke volume. Oxytocin-induced hypotension at cesarean delivery may be incorrectly attributed to blood loss. Pulse power analysis (also called "pulse contour analysis") of an arterial pressure wave form allows continuous evaluation of systemic vascular resistance and cardiac output in real time, thereby elucidating the causative factors behind changes in blood pressure. Pulse power analysis was conducted in six cases of cesarean delivery performed under neuraxial anesthesia. Hypotension in response to oxytocin was associated with a decrease in systemic vascular resistance and a compensatory increase in stroke volume, heart rate and cardiac output. Pulse power analysis may be helpful in determining the etiology of and treating hypotension during cesarean delivery under neuraxial anesthesia. Publication Types: Case Reports PMID: 18513945 [PubMed - indexed for MEDLINE] 3: Br J Anaesth. 2008 May;100(5):683-9. Epub 2008 Apr 2. Signs of myocardial ischaemia after injection of oxytocin: a randomized double-blind comparison of oxytocin and methylergometrine during Caesarean section. Svanström MC, Biber B, Hanes M, Johansson G, Näslund U, Bålfors EM. Department of Thoracic Anaesthesiology, Umeå University Hospital, SE-901 85 Umeå, Sweden. BACKGROUND: ECG changes, similar to those seen during myocardial ischaemia, together with symptoms of chest pain, are common during Caesarean section (CS). We hypothesized that oxytocin administration has cardiovascular effects leading to these symptoms and ECG changes. METHODS: Forty women undergoing elective CS under spinal anaesthesia were given an i.v. bolus of either 10 IU of oxytocin (Group OXY-CS, n=20) or 0.2 mg of methylergometrine (Group MET-CS, n=20), in a double-blind, randomized fashion after delivery. Ten healthy, non-pregnant, non-anaesthetized women were used as normal controls (Group OXY-NC, n=10) and were given 10 IU of oxytocin i.v. Twelve-lead ECG, on-line, computerized vectorcardiography (VCG), and invasive arterial pressure were recorded. RESULTS: Oxytocin produced a significant increase in heart rate, +28 (SD 4) and +52 (3) beats min(-1) [mean (SEM); P<0.001], decreases in mean arterial pressure, -33 (2) and -30 (3) mm Hg (P<0.001), and increases in the spatial ST-change vector magnitude (STC-VM), +77 (12) and +114 (8) microV (P<0.001), in CS patients and controls, respectively. Symptoms of chest pain and subjective discomfort were simultaneously present. Methylergometrine produced mild hypertension and no significant ECG changes. CONCLUSIONS: Oxytocin administered as an i.v. bolus of 10 IU induces chest pain, transient profound tachycardia, hypotension, and concomitant signs of myocardial ischaemia according to marked ECG and STC-VM changes. The effects are related to oxytocin administration and not to pregnancy, surgical procedure, delivery, or sympathetic block from spinal anaesthesia. Publication Types: Comparative Study Randomized Controlled Trial Research Support, Non-U.S. Gov't PMID: 18385263 [PubMed - indexed for MEDLINE] 4: BJOG. 2008 Apr;115(5):579-84. Oxytocin-ergometrine co-administration does not reduce blood loss at caesarean delivery for labour arrest. Balki M, Dhumne S, Kasodekar S, Kingdom J, Windrim R, Carvalho JC. Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto, Ontario, Canada. mrinalini.balki@uhn.on.ca OBJECTIVE: To determine if intravenous infusion of a combination of oxytocin and ergometrine maleate is better than oxytocin alone to decrease blood loss at caesarean delivery for labour arrest. DESIGN: Prospective, double-blinded, randomised controlled trial. SETTING: Mount Sinai Hospital, Toronto, Canada. POPULATION: Women undergoing caesarean deliveries for labour arrest. METHODS: Forty-eight women were randomised to receive infusion of either ergometrine maleate 0.25 mg + oxytocin 20 iu or oxytocin 20 iu alone, diluted in 1 l of lactated Ringer's Solution, immediately after delivery of the infant. Unsatisfactory uterine contractions after delivery were treated with additional boluses of the study solution or rescue carboprost. Blood loss was estimated based on the haematocrit values before and 48 hours after delivery. MAIN OUTCOME MEASURES: The primary outcome was the estimated blood loss, while the secondary outcomes included the use of additional uterotonics, need for blood transfusion and the incidence of adverse effects. RESULTS: The estimated blood loss was similar in the oxytocin-ergometrine and oxytocin-only groups; 1218 +/- 716 ml and 1299 +/- 774 ml, respectively (P = 0.72). Significantly fewer women required additional boluses of the study drug in the oxytocin-ergometrine group (21 and 57%; P = 0.01). Nausea (42 and 9%; P = 0.01) and vomiting (25 and 4%; P = 0.05) were significantly more prevalent in the oxytocin-ergometrine group. CONCLUSIONS: In women undergoing caesarean delivery for labour arrest, the co-administration of ergometrine with oxytocin does not reduce intraoperative blood loss, despite apparently superior uterine contraction. Publication Types: Randomized Controlled Trial Research Support, Non-U.S. Gov't PMID: 18333937 [PubMed - indexed for MEDLINE] 5: Eur J Obstet Gynecol Reprod Biol. 2008 Mar;137(1):27-30. Epub 2007 Jun 4. Use of oxytocin to prevent haemorrhage at caesarean section--a survey of practice in the United Kingdom. Wedisinghe L, Macleod M, Murphy DJ. Department of Obstetrics & Gynaecology, Ninewells Hospital & Medical School, Dundee DD1 9SY, United Kingdom. OBJECTIVE: To establish the views and current practice of obstetricians and anaesthetists with regard to the use of oxytocin to prevent haemorrhage at caesarean section. STUDY DESIGN: A national survey of all lead consultant obstetricians and anaesthetists for the labour ward in the United Kingdom. A postal questionnaire was sent to all clinicians with one subsequent reminder to non-responders. The use of oxytocin bolus and infusion, perceived side effects of intravenous oxytocin, estimated blood loss at caesarean section, and willingness to participate in a future clinical trial were explored. RESULTS: The response rate was 84% (365 respondents). A slow bolus of 5 IU oxytocin was the preferred approach of obstetricians and anaesthetists (153, 86% and 171, 92%, respectively). Oxytocin infusions were used routinely by 72 clinicians (20%) with selective use for particular clinical circumstances by 289 (80%). Most clinicians used either 30 IU (158, 43%) or 40 IU (192, 53%) infusions over 4h, with a total of 38 different regimens. The perceived risk of side effects with an oxytocin infusion was low. Estimated "average" blood loss varied (150-1,500 ml) with 56 clinicians (17%) and 93 (28%) reporting a >20% risk of postpartum haemorrhage for elective and emergency caesarean sections, respectively. CONCLUSION: There is wide variation in the use of oxytocin at caesarean section reflecting limited research in this area. Excess haemorrhage is considered to occur frequently and the perceived risk of oxytocin bolus and infusion is low. Further research is required addressing the optimal use of oxytocic agents at caesarean section. Publication Types: Research Support, Non-U.S. Gov't PMID: 17544563 [PubMed - indexed for MEDLINE]