Comparative dose-response study of hyperbaric ropivacaine for spinal anesthesia for cesarean delivery in singleton versus twin pregnancies.

STUDY OBJECTIVE: It is controversial whether local anesthetic dose requirement for spinal anesthesia for cesarean delivery differs between patients with singleton and patients with multiple gestation pregnancies. The aim of this study was to determine and compare the ED50 and ED90 for hyperbaric ropivacaine used for spinal anesthesia for cesarean delivery in patients with singleton pregnancies versus patients with twin pregnancies. DESIGN: Prospective, randomized, comparative dose-finding study. SETTING: Operating room, Women's Hospital, Zhejiang University School of Medicine. PATIENTS: 100 patients with singleton pregnancies (Group S) and 100 patients with twin pregnancies (Group T) presenting for scheduled cesarean delivery under combined spinal-epidural anesthesia were enrolled in the study. INTERVENTIONS: Patients in Group S or Group T were randomly allocated to receive 9.5, 11, 12.5, 14 or 15.5 mg of hyperbaric ropivacaine intrathecally. A dose was considered effective when it achieved a bilateral sensory block level at the T6 dermatome or above within 10 min after intrathecal injection, there was no numerical rating scale (NRS) pain score ≥ 3 intraoperatively, and there was no requirement for epidural supplementation at any time during anesthesia and operation. Values for ED50 and ED90 for ropivacaine were determined using probit regression. The difference in ropivacaine dose requirement between patients with singleton pregnancies and patients with twin pregnancies was assessed by calculating relative median potency. MEASUREMENTS: Success rates for different intrathecal doses of ropivacaine, side effects and neonatal outcomes were recorded. MAIN RESULTS: The estimated (95% confidence interval) values for ED50 and ED90 of intrathecal ropivacaine in patients with singleton pregnancies were 11.2 (10.2 to 12.0) mg and 15.7 (14.4 to 18.3) mg, respectively. The values for ED50 and ED90 in patients with twin pregnancies were 10.5 (9.5 to 11.3) mg and 14.8 mg (13.6 to 17.0) mg, respectively. The estimate of relative median potency for ropivacaine between patients with singleton and twin pregnancies was 0.94 (95% confidence interval 0.83 to 1.04). CONCLUSION: Patients with singleton and twin pregnancies have similar dose requirement for hyperbaric ropivacaine used for spinal anesthesia for cesarean delivery in the setting of combined spinal-epidural (CSE) anesthesia, no opioids, low weight cohort, insertion with the patients in the right lateral position, and norepinephrine boluses.

Comparison of cell salvage with one and two suction devices during cesarean section in patients with placenta previa and/or accrete: a randomized controlled trial.

BACKGROUND: Cell salvage has recently been recommended for obstetric use in cases with a high risk of massive hemorrhage during cesarean section (CS). However, limited data are available to support the use of one suction device to collect lost blood. This study aimed to investigate the volume of red blood cells (RBCs) salvaged and the components of amniotic fluid (AF) in blood salvaged by one suction device or two devices during CS in patients with placenta previa and/or accrete. METHODS: Thirty patients with placenta previa and/or accrete undergoing elective CS in the Women's Hospital of Zhejiang University School of Medicine were recruited for the present study from November 1, 2017 to December 1, 2018. The patients were randomly assigned to one of the two groups according to an Excel-generated random number sheet: Group 1 (n = 15), in which only one suction device was used to aspirate all blood and AF, and Group 2 (n = 15), in which a second suction device was mainly used to aspirate AF before the delivery of the placenta. Three samples of blood per patient (pre-wash, post-wash, and post-filtration) were collected to measure AF components. The salvaged RBC volumes were recorded. Continuous data of pre-wash, post-wash, and post-filtration samples were analyzed by using one-way analysis of variance with Tukey's test for multiple comparisons, or Kruskal-Wallis test with Dunn test for multiple comparisons. Comparisons of continuous data between Group 1 and Group 2 were conducted using Student's t test or Mann-Whitney U test. RESULTS: The salvaged RBC volume was significantly higher in Group 1 than that in Group 2 (401.6 ±â€Š77.2 mL vs. 330.1 ±â€Š53.3 mL, t = 4.175, P < 0.001). In both groups, squamous cells, lamellar bodies, and fat were significantly reduced by washing (all P<0.001) and squamous cells were further reduced by filtering (P < 0.001). Squamous cells were found in six post-filtration samples (three from each group). Lamellar bodies and fat were completely removed by filtering. Insulin-like growth factor binding protein 1, alpha-fetoprotein, albumin, lactate dehydrogenase, and potassium were significantly reduced post-wash (all P < 0.05), with no further significant reduction after filtration in either group (all P > 0.05). The mean percentage of fetal RBCs post-filtration was (1.8 ±â€Š0.8)% with a range of 1.0% to 3.5% and (1.9 ±â€Š0.9)% with a range of 0.7% to 4.0% in Groups 1 and 2, respectively, showing no significant difference between the two groups (U = 188.5, P = 0.651). CONCLUSION: Cell salvage performed by one suction device could result in higher volume of salvaged RBCs and can be used safely for CS in patients with placenta previa and/or accrete when massive hemorrhage occurs. TRIAL REGISTRATION NUMBER: ChiCTR-INR-17012926, http://www.chictr.org.cn/ Chinese Clinical Trial Registry.