A comparative study on infusion of usual dose of oxytocin and 80 units dose of oxytocin in the prevention of postpartum hemorrhage in cesarean section

The optimal oxytocin infusion rate for preventing uterine atony during cesarean delivery in elderly parturients with prior history of cesarean delivery

Background: An estimate of 90% effective dose (ED90) of oxytocin infusion has already been proved effective in non-laboring parturients. However, the requirements of oxytocin for elderly parturients with prior history of cesarean delivery (CD) may be higher. The aim of this study was to find the optimum oxytocin infusion rate for preventing uterine atony during CD in elderly parturients with prior history of CD. Method: We performed a randomized, double-blinded study in 120 healthy elderly parturients with prior history of CD scheduled for elective CD under combined spinal-epidural (CSE) anesthesia. Participants were treated with oxytocin infusion randomly at the rates of 0, 4, 8, 12, 16, or 20 IU h-1 after the delivery of infants. Following oxytocin administration, a blinded obstetrician evaluated the uterine tone (UT), verbally describing it using numerical scales (0-10: 0, no UT; 10, optimal UT) as either adequate or inadequate at the time intervals of 3, 6, and 9 min. Maternal adverse effects, requirements for additional uterotonic agents, delivery-placenta delivery time (PD), and estimated blood loss (EBL) were recorded. Results: The 50% effective dose (ED50) and 90% effective dose (ED90) of oxytocin infusion were 14.6 IU h-1 (95% confidence interval 12.0-18.4 IU h-1) and 27.7 IU h-1 (95% confidence interval 22.5-39.4 IU h-1), respectively. As the rate of infusion was increased in parturients, the rescue oxytocin dose and delivery-PD time were decreased. Parturients who received 0 IU h-1 oxytocin at 3, 6, and 9 min obtained lower UT scores than those who received 16 and 20 IU h-1 oxytocin (p < 0.05, respectively). No significant differences were observed among groups in EBL and maternal adverse effects. Conclusion: The infusion rate of oxytocin at 14.57 and 27.74 IU h-1 produces adequate UT in 50% and 90% of elderly parturients with prior history of CD, respectively. An oxytocin infusion rate of 27.7 IU h-1 is suggested to be the optimal dose for preventing uterine atony during CD in elderly parturients with prior history of cesarean delivery. Clinical Trial Registration: [https://www.chictr.org.cn/bin/project/edit?pid=62489], Identifier: [ChiCTR2000038891].

Investigation of The Effects of Oxytocin Administration Timing on Postpartum Hemorrhage during Cesarean Section

Background and Objectives: To determine and compare the effects of the timing of oxytocin administration (routinely used for intraoperative uterotonic purposes in cesarean section (CS) deliveries in our clinic) on the severity of postpartum hemorrhage following CS. Materials and Methods: All study participants (n = 216) had previous cesarean deliveries, were 38-40 weeks pregnant, and had CS planned under elective conditions. The cases were randomly divided into two groups: one group (n = 108) receiving oxytocin administration before the removal of the placenta (AOBRP) and another group (n = 108) receiving oxytocin administration after the removal of the placenta (AOARP). In all cases, the placenta was removed using the manual traction method. The standard dose of oxytocin is administered as an intravenous (IV) push of 3 international units (IU); simultaneously, 10 IU of oxytocin is added to 1000 cc isotonic fluid and given as an IV infusion at a rate of 250 cc/h. All methods and procedures applied to both groups were identical, except for the timing of administration of the standard oxytocin dose. Age, body mass index (BMI), parity, gestational week, preoperative hemoglobin (HB) and hematocrit (HTC), postoperative 6th and 24th hour HB-HTC, intraoperative hemorrhage, additional uterotonic need during cesarean section, postoperative hemorrhage (number of pads), need for blood transfusion during or after cesarean section, cesarean section time, and postpartum newborn baby weight were evaluated. Results: Age (year), BMI (kg/m²), parity, gestational week, surgical time, and newborn weight (g) did not differ between the groups (p > 0.05). The AOBRP group had significantly higher postoperative 6th hour HB and HTC and postoperative 24th hour HB and HTC values (p < 0.05). The intraoperative hemorrhage level was higher in the AOARP group (p = 0.000). Conclusions: The administration of oxytocin before placenta removal did not change the volume of bleeding in the postoperative period but significantly reduced the volume of bleeding in the intraoperative period. Therefore, in the postoperative period, the HB and HTC values of the AOBRP group were higher than those of the AOARP group.

The utero-tonic effects of low dose intravenous ketamine in cesarean section under spinal anesthesia; A randomized double-blind clinical trial

Background

Recently, the prevalence of cesarean section (CS) has been on the rise and the proper uterine tone is an important issue. We investigated the effects of intravenous (IV) ketamine on intraoperative bleeding and the need for oxytocin in CS under spinal anesthesia (SA).

Methods

This study, took place at Alzahra hospital during 2020. Pregnant women candidate for elective CS under SA were divided into two groups of ketamine and placebo. In group K, after umbilical cord clamping, 0.25 mg/kg ketamine and in group P 2ccs normal saline was injected. Mean arterial pressure and heart rate were recorded at baseline, before and 5 minutes after cord clamping and at the end of the surgery. The drop in hemoglobin values, the administrated units of oxytocin and side effects were also recorded.

Results

No significant difference was found in terms of patients' demographic data (P ≥ 0.05). The mean units of administrated oxytocin in group K was 34.61±6.63 and in group P; 48.47±12.15, which was significantly different (P=0.0001). The drop in Hb was less in group K, however not statistically significant (P=0.094). The need for methergine was significantly higher in group P (P=0.0001). The mean HR was significantly higher in group P (P=0.027), however, no significant difference was observed regarding the MAP (P=0.064). The incidence of hallucination (4.8%) and nystagmus (21%) was significantly higher in group K (P= 0.0001), but nausea and vomiting were more significant in group P (P= 0.027).

Conclusion

Prophylactic administration of low-dose ketamine in CS under S.A could significantly reduce the administrated oxytocin units and the need for additional utero-tonics and was associated with less drop in Hb values.

Intravenous oxytocin regimens in patients undergoing cesarean delivery: a systematic review and network meta-analysis of cluster-based groups

Information on evaluations of different oxytocin regimens used to prevent post-partum hemorrhage during cesarean delivery is scarce, and there is a lack of statistically pooled results for comparative doses. In this review, we aimed to analyze the effectiveness of different oxytocin regimens used and rank them accordingly. We performed a meta-analysis of randomized controlled trials (RCTs) reporting the incidence of additional uterotonic (AUT) use or amount of blood loss during cesarean delivery, where different oxytocin regimens were compared. Cluster analysis was used to define different clusters of oxytocin therapy based on the identified variable regimens. During the frequentist network meta-analysis, all clusters were compared to bolus clusters of dose range 3-5 IU. Data from 33 RCTs (6741 patients) to 26 RCTs (5422 patients) were assessed for AUT use and blood loss, respectively. Pairwise meta-analysis revealed a significant reduction in the use of AUTs or blood loss was recorded for bolus-infusion combination regimens. The network meta-analysis found that combined bolus-infusion regimens of (i) 3-5 IU and 0.25-1 IU/min or (ii) 3-5 IU and < 0.25 IU/min had statistically significant results for lowest consumption of AUTs (Ranks 1 and 2, respectively); whereas with the latter's use, the lowest blood loss (Rank 2) was observed. In contrast, the dose range, > 5 IU regimen was associated with higher side effects (lowest rank). During cesarean delivery, a significant reduction in the use of AUTs or blood loss (Rank 2) was recorded for bolus-infusion combination regimens. High doses did not have enough evidence to draw meaningful conclusions.

Side-effects of oxytocin in postpartum hemorrhage: a systematic review and meta-analysis

OBJECTIVE

To evaluate the side-effects of oxytocin for the prevention of postpartum hemorrhage (PPH) in randomized controlled trials (RCTs).

METHODS

Electronic databases (Web of Science, Embase, PubMed, Elsevier ScienceDirect, the Cochrane Library, and ClinicalTrials.gov) were searched from the beginning of indexing to Sep 2021. RCTs comparing oxytocin with non-oxytocin uterotonic agent(s) or non-pharmacologic interventions for the prevention of PPH were eligible.

RESULTS

Overall, sixty-one RCTs meeting the inclusion criteria were included, involving 68834 participants. Twenty-seven types of side-effects were reported in this study. There were 24, 35, or 2 trials assessed as high medium and low quality, respectively. Compared with non-oxytocin, oxytocin had significantly lower risk for shivering (RR=0.31, 95% CI=0.23-0.41, n=36680), fever (RR=0.27, 95% CI=0.20-0.37, n=34031), and diarrhea (RR=0.48, 95% CI=0.35-0.66, n=30883). Other side-effects were not found associated with oxytocin.

CONCLUSION

Oxytocin use was association with a significantly lower incidence of shivering, fever, and diarrhea events and did not increase risk of other side-effects during the third stage of labor. These observations may aid obstetricians and gynecologists in weighing up the benefits and risks associated with oxytocin in prevention and treatment of PPH during the third stage of labor.

Intravenous oxytocin dosing regimens for postpartum hemorrhage prevention following cesarean delivery: a systematic review and meta-analysis

OBJECTIVE

To compare the available evidence on intravenous oxytocin dosing regimens for the prevention of postpartum hemorrhage following cesarean delivery.

DATA SOURCES

We searched Ovid MEDLINE, Embase, Global Index Medicus, Cumulative Index of Nursing and Allied Health Literature, Cochrane Controlled Register of Trials, ClinicalTrials.gov, and the International Clinical Trials Registry Platform for eligible studies published until February 2020.

STUDY ELIGIBILITY CRITERIA

We included any randomized or nonrandomized study published in peer-reviewed journals that compared at least 2 different dosing regimens of intravenous oxytocin for postpartum hemorrhage prevention in women undergoing cesarean delivery.

METHODS

Two authors independently assessed the eligibility of studies, extracted the data, and assessed the risk of bias. The primary outcome was incidence of postpartum hemorrhage ≥1000 mL. Other review outcomes included use of additional uterotonics, blood loss, and adverse maternal events. Data were analyzed according to the type of intravenous administration (bolus only, infusion only, or bolus plus infusion) and total oxytocin dose. A meta-analysis was performed on randomized trials and the results were reported as risk ratios or mean differences with 95% confidence intervals. The Grading of Recommendations, Assessment, Development, and Evaluations scale was used to rate the certainty of evidence. Findings from dose-finding trials and nonrandomized studies were reported narratively.

RESULTS

A total of 35 studies (7333 women) met our inclusion criteria and included 30 randomized trials and 5 nonrandomized studies. There were limited data available from the trials for most outcomes, and the results were not conclusive. Compared with bolus plus infusion regimens, bolus only regimens probably result in slightly higher mean blood loss (mean difference, 52 mL; 95% confidence interval, 0.4-104 mL; moderate certainty). Among the bolus plus infusion regimens, initial bolus doses <5 IU may reduce nausea (risk ratio, 0.26; 95% confidence interval, 0.11-0.63; low certainty) when compared with doses of 5-9 IU. Total oxytocin doses of 5-9 IU vs total doses of 10-19 IU may increase the use of additional uterotonics (risk ratio, 13.00; 95% confidence interval, 1.75-96.37; low certainty). Effects on other outcomes were generally inconclusive.

CONCLUSION

There are limited data available for comparisons of IV oxytocin regimens for postpartum hemorrhage prevention following cesarean delivery. Bolus plus infusion regimens may lead to minor reductions in mean blood loss and initial bolus doses of <5 IU may minimize nausea. Bolus only regimens of 10 IU vs bolus only regimens of 5 IU may decrease the need for additional uterotonics, however, further comparative trials are required to understand the effects on other key outcomes, particularly hypotension.

Physiology and Pathology of Contractility of the Myometrium

Uterine atony is a serious obstetrical complication since it is the leading cause of postpartum hemorrhage. Postpartum hemorrhage (PPH) is one of the 5 major causes of postpartum mortality; therefore, it requires immediate medical intervention, independent of whether delivery occurs normally or with a cesarean section. While in the past years most cases of postpartum hemorrhage were caused due to uterine atony following vaginal delivery, in recent years most PPH cases indicate a significant association with cesarean delivery. There are several methods used in order to avoid such a life-threatening complication, ranging from risk assessment to prevention, and finally medical intervention and management, if such an event occurs. In this scientific paper emphasis is given on the so-called "uterotonic" agents that are currently used, including oxytocin among others. It is, therefore, important to be familiar with these agents as well as understand the physiological mechanism by which they work, since they are used in everyday practice, not only for managing but also for preventing PPH. There are several potential questions that arise from the use of such "uterotonic" agents, and most specifically of oxytocin. Maybe one of the most important issues is the determination of optimal dosing of oxytocin in order to avoid PPH after a cesarean section.

Role of dyslipidemia in the development of early-onset preeclampsia

Preeclampsia (PE) is a gestational-related disease presented with hypertension, peripheral edema, and proteinuria after 20 weeks of gestation. In PE, there are various metabolic changes like dyslipidemia. In addition, both PE and dyslipidemia are associated with changes of platelet indices. Thus, objective of the current study was to illustrate the potential role of dyslipidemia and platelet changes in pregnant women with PE. This case–control study involved 37 preeclamptic pregnant women as compared to 24 healthy pregnant women as controls. Blood pressure profile, lipid profile, proteinuria, and platelet indices were measured. Blood pressure profile was higher in preeclamptic pregnant women as compared to the controls (P < 0.01). There was a significant dyslipidemic status in preeclamptic pregnant women compared with the controls (P < 0.01). Platetetcrit (PCT) and platelet count (PC) were lower in preeclamptic pregnant women compared with the controls (P = 0.001). On the other hand, platelet distribution width (PDW), mean platelet volume (MPV), and platelet-large cell ratio (P-LCR) were higher in the pregnant women with PE as compared with the controls (P = 0.001). PCT and PC were insignificantly linked, while P-LCR, MPV and PDW were significantly correlated with total cholesterol, triglyceride, low-density lipoprotein (LDL)/high-density lipoprotein (HDL) ratio, systolic blood pressure, DBP, and MAP in preeclamptic patients compared with women of normal pregnancy. Both dyslipidemia and alterations in the platelet indices are correlated with blood pressure profile in PE. High MPV and PDW in association with high LDL/HDL ratio in pregnant women herald risk of PE.