Predictive accuracy of the shock index for severe postpartum hemorrhage in high-income countries: A systematic review and meta-analysis

Impact of the 2017 revised Japanese obstetric hemorrhage management guidelines on tranexamic acid use in patients undergoing cesarean delivery: an interrupted time series analysis

BACKGROUND

Tranexamic acid is one component of a complex management algorithm for postpartum hemorrhage. In Japan, the 2010 obstetric hemorrhage management guidelines was revised in 2017, adding the recommendation for the administration of tranexamic acid for postpartum hemorrhage. This research aims to delineate the temporal trends in tranexamic acid administration in patients undergoing cesarean deliveries and to examine the impact of the obstetric hemorrhage management guidelines implementation.

METHODS

An interrupted time series analysis was conducted on data from patients who underwent cesarean deliveries from April 2012 to August 2021, sourced from Japan's nationwide health insurance claims database. We examined the trends of tranexamic acid usage and blood transfusion use before and after the implementation of the revised guidelines in 2017.

RESULTS

The study cohort comprised 91 166 cesarean deliveries. Prior to the guideline implementation, the rate of tranexamic acid usage decreased. Post-guidelines implementation, there was a statistically significant increase in the rate of tranexamic acid use, with a quarterly percentage change of 0.48% (95% confidence interval: 0.36 to 0.60; P < 0.001). The guidelines implementation in 2017 was not significantly associated with a change in the rate of transfusions.

CONCLUSIONS

This interrupted time series analysis demonstrated a significant increase in the rate of tranexamic acid administration following the implementation of the revised guidelines, reversing the previously observed downward trend. Our findings could reflect the impact of the revised guideline on the use of tranexamic acid for postpartum hemorrhage, but this did not translate to fewer blood transfusions.

Predictive performance of Shock Index for postpartum hemorrhage during cesarean delivery

BACKGROUND

The Shock Index (SI), defined as heart rate divided by systolic blood pressure, is reportedly an early surrogate indicator for postpartum hemorrhage (PPH). However, most previous studies have used clinical data of women who delivered vaginally. Therefore, we aimed to evaluate the SI pattern during cesarean delivery and determine its usefulness in detecting PPH.

METHODS

This was a single-center retrospective study using the clinical data of women (n = 331) who underwent cesarean delivery under spinal anesthesia at term between 2018 and 2021. We assessed the SI pattern stratified by total blood loss and evaluated the predictive performance of each vital sign in detecting PPH (total blood loss ≥1000 mL) based on the area under the receiver operating characteristic curve (AUROC).

RESULTS

At 10-15 min after delivery, the mean SI peaked between 0.84 and 0.90 and then decreased to a level between 0.72 and 0.77, which was similar to that upon entering the operating room. Among 331 women, 91 (27.5%) were diagnosed with PPH. There was no correlation between SI and total blood loss (rs = 0.02). The SI had low ability to detect PPH (AUROC 0.54, 95% confidence interval 0.47 to 0.61), which was similar to other vital signs (AUROCs 0.53-0.56).

CONCLUSION

We determined the pattern of SI during cesarean delivery. We found no correlation between SI and total blood loss. Unlike in vaginal delivery, the prognostic accuracy of SI for PPH detection in cesarean delivery was low.

Shock index as a predictor of postpartum haemorrhage after vaginal delivery: Secondary analysis of a multicentre randomised controlled trial

OBJECTIVE

To describe the shock index (SI) distribution during the first 2 hours after delivery and to evaluate its performance when measured 15 and 30 minutes after delivery for predicting postpartum haemorrhage (PPH) occurrence in the general population of parturients after vaginal delivery.

DESIGN

Secondary analysis of a multicentre randomised controlled trial testing prophylactic administration of tranexamic acid versus placebo in addition to prophylactic oxytocin to prevent PPH.

SETTING

15 French maternity units in 2015-2016.

SAMPLE

3891 women with a singleton live fetus ≥35 weeks, born vaginally.

METHODS

For each PPH-related predicted outcome, we calculated the area under the receiver operating characteristic curve (AUROC) values of the SI at 15 and 30 minutes after delivery and its predictive performance for SI cut-off values of 0.7, 0.9 and 1.1.

MAIN OUTCOME MEASURES

Quantitative blood loss ≥1000 ml (QBL ≥1000 ml) measured in a graduated collector bag and provider-assessed clinically significant PPH (cPPH).

RESULTS

Prevalence of QBL ≥1000 ml and cPPH was respectively 2.7% (104/3839) and 9.1% (354/3891). The distributions of the SI at 15 and 30 minutes after delivery were similar with a median value of 0.73 and 97th percentile of 1.11 for both. The AUROC values of the 15-minute SI for discriminating QBL ≥1000 ml and cPPH were respectively 0.66 (lower limit of the 95% confidence interval [LCI] 0.60) and 0.56 (LCI 0.52); and for the 30-minute SI 0.68 (LCI 0.61) and 0.49 (LCI 0.43).

CONCLUSIONS

The shock index at 15 and 30 minutes after delivery did not satisfactorily predict either QBL ≥1000 ml or clinical PPH.

Epidemiology and definition of PPH worldwide

Postpartum/peripartum hemorrhage (PPH) is an obstetric emergency complicating 1-10% of all deliveries and is a leading cause of maternal mortality and morbidity worldwide. However, the incidence of PPH differs widely according to the definition and criteria used, the way of measuring postpartum blood loss, and the population being studied with the highest numbers in developing countries. Despite all the significant progress in healthcare, the incidence of PPH is rising due to an incomplete implementation of guidelines, resulting in treatment delays and suboptimal care. A consensus clinical definition of PPH is needed to enable awareness, early recognition, and initiation of appropriate intensive treatment. Unfortunately, the most used definition of PPH based on blood loss ≥500 ml after delivery suffers from inaccuracies in blood loss quantification and is not clinically relevant in most cases, as the amount of blood loss does not fully reflect the severity of bleeding.