Anesthetic Management in Caesarean Delivery of Women With Placenta Previa

A Retrospective Cohort Study

Dazhi Fan; Jiaming Rao; Dongxin Lin; Huishan Zhang; Zixing Zhou; Gengdong Chen; Pengsheng Li; Wen Wang; Ting Chen; Fengying Chen; Yuping Ye; Xiaoling Guo; Zhengping Liu

Disclosures

BMC Anesthesiol. 2021;21(247) 

In This Article

Methods

We performed a retrospective cohort study between the years 2014–2019 in a high-volume delivery suite in China, which is a tertiary referral medical center with approximately 13,000 deliveries each year.[14] The study was approved by the institutional review board (number FSFY-MEC-2019-044) and was conducted in accordance with the ethical standards described in an appropriate version of the 1975 Declaration of Helsinki, as revised in 2000.

Pregnant women who met the following inclusion criteria were included for analysis: 1) placenta preiva diagnosed by ultrasound before delivery; 2) placenta previa confirmed during delivery by obstetrician; 3) pregnant women undergoing cesarean delivery; 4) singleton gestation. Placenta previa was diagnosed using the last trans-vaginal or -abdominal ultrasonography performed before delivery; transvaginal ultrasonography was preferred if the placenta was located in the posterior wall of the uterus. Trained physicians recorded the distance from the leading placental edge to the internal cervix os, and the placenta covers the cervical os.[3] Women whose pregnancies were terminated or who delivered before 27w6d were excluded from the cohort. Marginal placenta previa pregnancy women were also excluded. Patients with placenta accreta spectrum (PAS) were confirmed during surgery by clinical assessment of the surgical team and by histopathological examination after cesarean hysterectomy or uterus tissue.

Cesarean delivery was performed under general or neuraxial anesthesia. The choice of anesthesia method is determined by consultation between the obstetrician and the anesthesiologist, according to the patient's background and contraindications. The anesthetic was chosen by the anesthetist's preference. General anesthesia was performed with propofol (1.0 mg/kg), rocuronium bromide (0.6 mg/kg), and 3% sevofulrane (30 ml) followed by tracheal intubation and mechanical ventilation just before skin incision. Preparations for rapid blood and fluid replacement were made in all patients before surgery. Continuous pumping of propofol (1.0 mg/kg) and sufentanil (0.3 μg/kg) was performed to maintain the depth of anesthesia. Patients were preoxygenated with 100% oxygen via face mask for 2 min before induction. For neuraxial anesthesia, a 25-gauge pencil-point spinal needle is used to access the spinal space at the level of L2–3 or L3–4. Upon return of cerebrospinal fluid, 0.5% bupivacaine (12 mg) was injected. According to the needs of the operation, 2.0% ropivacaine was added to maintain intraoperative anesthesia.

All patients received oxytocin 20 units and carbetocin 100 μg intravenously drip immediately after delivery of the placenta to reducing the postpartum hemorrhage. Misoprostol 500 mg rectal and/or hemabate 250 mg intramuscular injection were given when the obstetrician complained of a noticeable bleeding in the lower part of the uterus following removal of the placenta.

Patients were identified from a prospective database of all patients with a diagnosis of placenta previa made during the study period. The data were collected retrospectively from the medical record after discharge. The database was updated every two weeks, and there were special personnel for maintenance and sampling inspection. Data was acquired using relevant electronic health record data including demographics, pregnancy characteristics, pathology findings, anesthesia method (general or neuraxial), operative time, anesthesia-to-delivery time, blood loss, hemoglobin concentration, Apgar score (1 min, 5 min, and 10 min), neonatal asphyxia, and admission to NICU (neonatal intensive care unit). The primary outcome was estimated blood loss (EBL). Blood loss was collected and measured using a drape with a blood collection system around the abdominal wound from the abdominal cavity during the cesarean delivery. Gauzes were used to collect blood from the vagina. All gauzes with blood were collected, weighed and an equivalent volume was calculated. The volume of blood loss is equal to the weight of blood loss ÷ 1.05. Any post-cesarean delivery blood loss was also quantified.[15] Secondary outcomes were transfusion blood rate, Apgar, and NICU. Blood transfusion during cesarean delivery was performed by the clinician in accordance with protocol.

Statistical analysis was completed using SPSS 21.0. Statistical assessment of our data was performed using descriptive statistics as well as t-tests, Wilcoxon rank-sum and chi-square test for continuous and categorical variables, respectively. Univariate analysis was performed to determine the role of the type of anesthesia in the outcomes, unadjusted odds ratios or beta coefficients, 95% confidence intervals, and 2-side p values were calculated. Multivariate logistic or line regressions were further performed, and adjusted odds ratios or beta coefficients were calculated, as well. Variables with a p-value < 0.05 in the univariate analysis were entered into the multivariate model. Potential confounders included gestational weeks, gravity, PAS, anterior placenta, previous cesarean delivery, previous placenta previa, antepartum hemorrhage, emergency cesarean delivery, and anesthesia-to-delivery time (min). Given that management for PAS cases is different from that for placenta previa, the results were re-calculated after excluding those cases with placenta previa complication with PAS.

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