Improving the accuracy of estimated blood loss at obstetric haemorrhage using clinical reconstructions

Reducing trainee mistakes. Better performance with changing to a high-fidelity simulation system?

BACKGROUND

Postpartum hemorrhage is a significant cause of both maternal morbidity and mortality worldwide and is increasing in incidence. This study aimed to assess improvement and identify shortcomings in trainee performance in different simulation systems in the management of postpartum hemorrhage.

OBJECTIVE

To perform a pilot study evaluating and comparing high- and low-fidelity simulation models, assessing improvement in repeated performance with high-fidelity mode and identifying mistakes made assessed using Objective Structured Assessment of Technical Skills and thereby exploring what aspects of emergency management of postpartum hemorrhage should be prioritized in teaching settings and assessing what simulation setup is most effective in achieving competence.

STUDY DESIGN

This was a prospective randomized, single-blinded, single-institution trial in a population of 17 junior obstetrical trainees at the Charité University Hospital Obstetric Simulation Center in Berlin. Trainees were randomized into 2 groups, with either initial low-fidelity simulation or high-fidelity simulation, followed by repeated assessment of performance, using the high-fidelity model simulation system. Individual simulation sessions were video-recorded and transcribed, and the timing of interventions was documented. Strandardized Objective Structured Assessment of Technical Skills forms were used as a checklist for performance.

RESULTS

There was a statistically significant general improvement in performance (P=.02; 24.7-27.2 of 31.0 points; average of 8.7%) in the second cycle of simulation assessment and a statistically significant training effect (P=.043; 24.4-28.4 of 31.0 points; average of 12.9%) in the group that underwent repeat simulation assessment from the initial low-fidelity system to the high-fidelity system compared with the group using the same high-fidelity setup (P=.276; 25.0-25.8 of 31.0; average of 2.4%).

CONCLUSION

There was an improvement in the performance when trainees underwent a repeated cycle of simulation assessment changing from a low-fidelity system to a high-fidelity system. Simulation assessment can identify mistakes and learning gaps that are important for obstetrical trainees. This study found that trainees make the same mistakes, regardless of which simulation model was initially used.

Prognostic Role of Initial Thromboelastography in Emergency Department Patients with Primary Postpartum Hemorrhage: Association with Massive Transfusion

BACKGROUND

The early prediction of the need for massive transfusions (MTs) and the preparation of blood products are essential for managing patients with primary postpartum hemorrhage (PPH). Thromboelastography (TEG) enables a thorough evaluation of coagulation status and is useful for guiding the treatment of hemorrhagic events in various diseases. We investigated the role of TEG in predicting the need for MT in patients with primary PPH.

METHODS

A retrospective observational study was conducted in the emergency department (ED) of a university-affiliated, tertiary referral center between November 2015 and August 2023. TEG was performed upon admission. We defined MT as the requirement for transfusion of more than 10 units of packed red blood cells within the first 24 h. The primary outcome was the need for MT.

RESULTS

Among the 184 patients with initial TEG, 34 (18.5%) required MT. Except for lysis after 30 min, the MT and non-MT groups had significantly different TEG values. Based on multivariate analysis, an angle < 60 was an independent predictor of MT (odds ratio (OR) 7.769; 95% confidence interval (CI), 2.736-22.062), along with lactate (OR, 1.674; 95% CI, 1.218-2.300) and shock index > 0.9 (OR, 4.638; 95% CI, 1.784-12.056). Alpha angle < 60 degrees indicated the need for MT with 73.5% sensitivity, 72.0% specificity, and 92.3% negative predictive value.

CONCLUSIONS

Point-of-care testing of TEG has the potential to be a useful tool in accurately predicting the necessity for MT in ED patients with primary PPH at an early stage.

Defining 'obstetric haemorrhage': Blood loss volume and severe morbidity

AIMS AND OBJECTIVES

Our goal is to describe the association between total quantitative blood loss (QBL) and risk of obstetric haemorrhage-related morbidity (OBH-M) to assess the utility of the current definition of obstetric haemorrhage (OBH).

METHODS

This was a retrospective cohort study completed of all patients who had a live delivery at the only urban safety-net hospital over a 2-year period from 2018 to 2019. We categorized deliveries into 10 equally sized deciles based on QBL and compared the proportion with OBH-M in each. Among the two deciles with the highest proportions of OBH-M, we stratified deliveries into seven groups of ascending intervals of 250cc QBL. Finally, we compared the positive predictive value (PPV) of the standard definition of OBH (QBL ≥ 1000cc) to a definition extrapolated from our stratified analysis. The primary outcome was proportion of deliveries within each QBL decile affected by OBH-M. The secondary outcome was PPV.

RESULTS

We found a significant increase in OBH-M from decile 9 (895-1201cc QBL) to decile 10 (1205-8325cc QBL) (p < 0.001). In our stratified analysis, we found QBL of 1500cc to be an inflection point for an increased proportion of OBH-M. Our secondary analysis showed an increased PPV for OBH-M using QBL of 1500cc (20.5%) compared with that of QBL 1000cc (9.8%).

CONCLUSIONS

Our findings suggest that a higher QBL threshold than the currently accepted definition of OBH is more predictive of OBH-M.

Serum Lactate Level as a Predictor for Blood Transfusion in Postpartum Hemorrhage

OBJECTIVE

Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and mortality. At present, there are no reliable clinical or laboratory indicators to identify which patients might require blood transfusions during a PPH. Serum lactate has long been used as an early biomarker of tissue hypoperfusion in trauma settings. The aim of this study is to understand serum lactate's role in the management of obstetric hemorrhage.

STUDY DESIGN

A retrospective chart review was performed of women who delivered between 2016 and 2019 at our institution and experienced a PPH. The patients were divided into two groups: those with a normal serum lactate level, defined as ≤2 mmol/L, and those with an abnormal serum lactate level, defined as >2 mmol/L. Need for packed red blood cell transfusion, as part of the resuscitation, was assessed for both groups.

RESULTS

During the study period, 938 women experienced PPH. Of these, 108 (11.5%) had a normal serum lactate, ≤2 mmol/L, and 830 (88.5%) had an abnormal lactate, >2 mmol/L. Women with elevated lactate levels were more likely to receive a blood transfusion versus those with a normal lactate level (57.0 vs. 46.3%, p = 0.035, respectively). Additionally, the average number of blood transfusions administered was significantly higher in the abnormal lactate group versus in the normal lactate group (1.34 vs. 0.97, respectively, p = 0.004). In a multivariable linear regression model, increasing serum lactate levels were found to be predictive of requiring more than 1 unit of blood (p < 0.001).

CONCLUSION

Women with elevated serum lactate levels were more likely to require blood transfusions during a PPH versus those with a normal serum lactate level. Thus, serum lactate levels are useful as an early indicator of requirement for blood transfusion in the management of obstetric hemorrhage.

KEY POINTS

· Lactate is a biomarker for blood transfusion in trauma.. · Lactate's role in PPH is unknown.. · Elevated lactate predicts receiving more blood transfusions..

Management of Postpartum Hemorrhage in Critical Care Transport

Postpartum hemorrhage is a relatively common and highly morbid complication of the postpartum period that often requires management by specialized providers at tertiary care facilities. Critical care transport teams may be tasked with transporting postpartum patients who are already experiencing postpartum hemorrhage, but they should also be aware that other peripartum patients may be at risk for developing postpartum hemorrhage while in the process of transport. As such, it is imperative that transport providers understand the signs, symptoms, causes, and complications of postpartum hemorrhage as well as the options for intervention and treatment. This article reviews the current clinical evidence regarding resuscitation and medical management strategies that transport teams should be familiar with as well as more advanced and invasive management techniques they may encounter and be expected to monitor during transport, such as balloon tamponade and aortic balloon occlusion.

[Postpartum Hemorrhage]

Postpartum hemorrhage (PPH) affects about 4% of all deliveries in high-income countries and continues to rise, a trend attributable to the increase in caesarean section rates and maternal morbidity. Preventive measures such as the precautionary administration of uterotonics effectively reduce the risk of severe bleeding irrespective of birth mode. As a time-critical condition and a significant contributor to adverse maternal outcomes, PPH needs to be diagnosed early by measuring, not estimating, blood losses. Institutional treatment algorithms should be available to guide stage-based interdisciplinary management without delay. The main therapy goals are to identify the etiology and stop the bleeding by using uterotonics and mechanical and surgical interventions, to restore hemodynamic stability by volume and transfusion therapy and to optimize hemostasis by laboratory- and viscoelastic assay-guided factor replacement. This review highlights current recommendations for prevention, diagnosis and treatment of PPH.

Comparison of quantitative and calculated postpartum blood loss after vaginal delivery

BACKGROUND

Because there is no consensus on the method of assessing postpartum blood loss, the comparability and relevance of the postpartum hemorrhage-related literature are questionable. Quantitative blood loss assessment using a volumetric technique with a graduated collector bag has been proposed to overcome limitations of intervention-based outcomes but remains partly subjective and potentially biased by amniotic fluid or missed out-of-bag losses. Calculated blood loss based on laboratory parameters has been studied and used as an objective method expected to reflect total blood loss. However, few studies have compared quantitative with calculated blood loss.

OBJECTIVE

This study aimed to compare the distribution of postpartum blood loss after vaginal delivery assessed by 2 methods-quantitative and calculated blood loss-and the incidence of abnormal blood loss with each method.

STUDY DESIGN

Data were obtained from the merged database of 3 multicenter, randomized controlled trials, all testing different interventions to prevent postpartum blood loss in individuals with a singleton live fetus at ≥35 weeks of gestation, born vaginally. All 3 trials measured blood loss volume by using a graduated collector bag. Hematocrit was measured in the eighth or ninth month of gestation and on day 2 postpartum. The 2 primary outcomes were: quantitative blood loss, defined by the total volume of blood loss measured in a graduated collector bag, and calculated blood loss, mathematically defined from the peripartum hematocrit change (estimated blood volume × [(antepartum hematocrit-postpartum hematocrit)/antepartum hematocrit], where estimated blood volume [mL]=booking weight [kg] × 85). We modeled the association between positive quantitative blood loss and positive calculated blood loss with polynomial regression and calculated the Spearman correlation coefficient.

RESULTS

Among the 8341 individuals included in this analysis, the median quantitative blood loss (100 mL; interquartile range, 50-275) was significantly lower than the median calculated blood loss (260 mL; interquartile range, 0-630) (P<.05). The incidence of abnormal blood loss was lower with quantitative blood loss than calculated blood loss for all 3 thresholds: for ≥500 mL, it was 9.6% (799/8341) and 32.3% (2691/8341), respectively; for ≥1000 mL, 2.1% (176/8341) and 11.5% (959/8341); and for ≥2000 mL, 0.1% (10/8341) and 1.4% (117/8341) (P<.05). Quantitative blood loss and calculated blood loss were significantly but moderately correlated (Spearman coefficient=0.44; P<.05). The association between them was not linear, and their difference tended to increase with blood loss. Negative calculated blood loss values occurred in 23% (1958/8341) of individuals; among them, >99% (1939/1958) had quantitative blood loss ≤500 mL.

CONCLUSION

Quantitative and calculated blood loss were significantly but moderately correlated after vaginal delivery. However, clinicians should be aware that quantitative blood loss is lower than calculated blood loss, with a difference that tended to rise as blood loss increased.

Coagulation management and transfusion in massive postpartum hemorrhage

PURPOSE OF REVIEW

Excessive bleeding during and following childbirth remains one of the leading causes of maternal mortality.

RECENT FINDINGS

Current guidelines differ in definitions and recommendations on managing transfusion and hemostasis in massive postpartum hemorrhage (PPH). Insights gained from trauma-induced coagulopathy are not directly transferable to the obstetric population due to gestational alterations and a differing pathophysiology.

SUMMARY

Factor deficiency is uncommon at the beginning of most etiologies of PPH but will eventually develop from consumption and depletion in the absence of bleeding control. The sensitivity of point-of-care tests for fibrinolysis is too low and may delay treatment, therefore tranexamic acid should be started early at diagnosis even without signs for hyperfibrinolysis. Transfusion management may be initiated empirically, but is best to be guided by laboratory and viscoelastic assay results as soon as possible. Hypofibrinogenemia is well detected by point-of-care tests, thus substitution may be tailored to individual needs, while reliable thresholds for fresh frozen plasma (FFP) and specific components are yet to be defined. In case of factor deficiency, prothrombin complex concentrate or lyophilized plasma allow for a more rapid restoration of coagulation than FFP. If bleeding and hemostasis are under control, a timely anticoagulation may be necessary.

Postoperative care in the caesarean intensive care unit: experience from a tertiary maternity hospital

Objective

The aim was to determine whether follow-up in the intensive care unit (ICU) for the postoperative first eight hours was beneficial for early intervention in postpartum hemorrhage.

Material and Methods

In our hospital, all patients are admitted to the ICU for the first eight hours after cesarean section. Patients with postpartum hemorrhage after cesarean delivery who received medical and/or surgical treatment between 2016 and 2020 were reviewed in the presented study retrospectively.

Results

All cases (n=36,396) who underwent cesarean delivery were reviewed. Three hundred and fifty-nine patients with postpartum hemorrhage were identified and included. In the study group the time between cesarean section and diagnosis of postpartum hemorrhage was 10.1±19.1 hours, and the time between cesarean section and re-laparotomy was 9.26±23.1 hours. A total of three maternal deaths occurred after cesarean section in our hospital. In the last five years, the mortality rate in patients delivering by cesarean section was 3.9 per 100,000. The incidence of postpartum hemorrhage in cesarean deliveries at our hospital was calculated to be 1.0%, and the rate of obstetric near-miss events was calculated to be 0.6 per 1000 live births.

Conclusion

Follow-up of patients in the ICU in the first eight postoperative hours after cesarean section may result in a lower number of re-laparotomies due to postpartum hemorrhage, a shortened interval between cesarean section and re-laparotomy, and a lower maternal mortality rate.

Prevention of postpartum hemorrhage in vaginal deliveries

Identification of patients at risk for postpartum hemorrhage (PPH) may allow for prompt diagnosis and intervention. Individual risk factors, risk assessment tools and prediction models have been used for determining a patient's risk of PPH. Measures for the prevention of PPH include identification and management of iron deficiency anemia, unit readiness and preparedness through performing regular simulations and having a PPH cart or medication kit readily available, prophylactic uterotonic - carbetocin alone or dual agents such as oxytocin and misoprostol or oxytocin and methylergometrine or antifibrinolytic (oxytocin and tranexamic acid) use in the third stage of labor immediately after fetal head delivery, and controlled cord traction.

The hematological impact of umbilical cord milking versus delayed cord clamping in premature neonates: a randomized controlled trial

BACKGROUND

The hematological impact of umbilical cord milking (UCM) was compared to that of delayed cord clamping (DCC) as a faster placental transfusion technique for preterm neonates (between 24 and 34 + 6 weeks gestation). A comparison of important neonatal morbidities was also made.

METHODS

This was an open-label randomized trial conducted from June 8, 2017, to April 22, 2019. Two hundred patients with preterm deliveries (24 and 34 + 6 weeks gestation) were assigned to the DCC or UCM group at random at a ratio of 1:1. The study power was 80% for a difference in the hematocrit value of 3% and Hb value of one gram, and an alpha error of 0.05.

RESULTS

The following variables were analyzed in the comparison of UCM vs. DCC: first draw hemoglobin: 17.0 ± 1.9 vs. 16.8 ± 1.8 gm/dl (95% CI -0.75-0.29, P 0.383); first draw hematocrit: 55.6 ± 6.4 vs. 55.2 ± 6.4% (95% CI -2.18-1.38, P 0.659); peak hematocrit: 56.9 ± 6.4 vs. 56.3 ± 6.7% (95% CI -2.41-1.26, P 0.537); the need for respiratory assistance (47% vs. 30%, P 0.020), inotropes (16% vs. 6%, P 0.040), and blood transfusion (26% vs. 12%, P 0.018); and the occurrence of intraventricular hemorrhage (9% vs. 5%, P 0.407), necrotizing enterocolitis (6% vs. 2%, P 0.279), sepsis (25% vs. 15%, P 0.111), and neonatal death (13% vs. 4%, P 0.40).

CONCLUSION

UCM facilitated a rapid transfer of placental blood equivalent to that of DCC for premature neonates. However, it resulted in increased rates of interventions and morbidities, especially in extremely preterm neonates.

TRIAL REGISTRATION

The clinical trial was registered on May 10, 2017, with registration number (NCT03147846).

The Risk of Obstetrical Hemorrhage in Placenta Praevia Associated with Coronavirus Infection Antepartum or Intrapartum

Background and Objectives: The aim was to evaluate the severity of obstetrical bleeding in the third trimester associated with COVID infection in placenta previa and accreta. Materials and Methods: A retrospective study was conducted to compare the risk of obstetrical bleeding in the case of placenta previa with or without associated SARS-CoV-2 infection. Patients presenting with placenta previa before labor were classified into three groups: group A (control) as no infection throughout their pregnancy, group B as confirmed infection during the 1st trimester, and group C as confirmed infection at the time of delivery. Infected patients were stratified according to the severity of signs and symptoms. The severity of obstetrical hemorrhage at birth was assessed quantitatively and qualitatively. All placentas were analyzed histologically to identify similarities. Results: Prematurity and pregnancy-induced hypertension appear significantly related to SARS-CoV-2 infection during the 3rd trimester. Placenta accreta risk increases significantly with infection during the 1st trimester. No statistically significant differences in the severity of hemorrhage associated with childbirth in cases with placenta previa between groups A and C but increased obstetrical bleeding mainly due to emergency hemostatic hysterectomy in group B driven by placenta accrete were detected. Obstetrical hemorrhage at birth in the case of coexistence of the infection was found not to correlate with the severity of the viral disease. Meanwhile, the number of days of hospitalization after birth is related to the specific treatment of COVID infection and not related to complications related to birth. Conclusions: The study finds an increased incidence of placenta accreta associated with placenta previa in cases where the viral infection occurred in the first trimester of pregnancy, associated with an increased incidence of hemostasis hysterectomies in these patients. Placental histological changes related to viral infection are multiple and more important in patients who had COVID infection in the first trimester.

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

AIM

The shock index has been suggested as a screening tool for predicting postpartum hemorrhage (PPH); however, there is little comprehensive evidence regarding its predictive accuracy. This systematic review and meta-analysis aim to investigate the predictive accuracy of the shock index for severe PPH in high-income countries.

METHODS

A comprehensive search was conducted on MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science (from inception to June 2021). Studies assessing the predictive performance of the shock index for PPH in high-income countries were included. Two or more reviewers independently extracted the data and assessed the risk of bias and applicability concerns using the modified Quality Assessment of Diagnostic Accuracy Studies 2 tool. PPH requiring higher-level care, such as blood transfusions, were considered as primary analyses. We described the hierarchical summary receiver-operating characteristic curve for data synthesis.

RESULTS

Nine studies were included after the eligibility assessment. All studies were considered to either have a high risk of bias or high applicability concerns. The sensitivity of the four studies that defined severe PPH as PPH requiring blood transfusion ranged from 0.51 to 0.80, whereas their specificity ranged from 0.33 to 0.92.

CONCLUSIONS

This review shows that the predictive performance of the shock index for severe PPH is inconsistent. Therefore, the evidence for using the shock index alone as a screening tool for PPH in high-income countries is insufficient.

STUDY REGISTRATION

This review was prospectively registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000044230).

Route of postpartum oxytocin administration and maternal hemoglobin decline - A randomized controlled trial

OBJECTIVE

Oxytocin uterotonic agents are routinely administered during the third stage of labor, however, the administration route is varying, intravenously or intramuscularly. We aimed to compare the effect of different regimens of postpartum oxytocin administration on hemoglobin (Hb) and hematocrit (Hct) decline.

METHODS

A randomized, 3-arm study of women who delivered vaginally at term in a single tertiary medical center was conducted. Immediately following the delivery of the fetus women randomly received one of 3 oxytocin regimens: 1) intramuscular 10units (IM group); 2) intravenous 10units in 100 ml 0.9%NaCl solution over 10-15 min (IV group); or 3) combined IV + IM regimens (IV + IM group). Primary outcome was defined as the level of Hb decline between prepartum and postpartum measurements.

RESULTS

Overall, 210 women (70 in each group) were randomized, with 171 included in the final analysis (IM group-61, IV group-57, IV + IM group-53). There was no significant difference between the groups regarding maternal age, pre-pregnancy body-mass-index (BMI), parity, operative vaginal deliveries rate, the rate of episiotomy or perineal tears or neonatal birthweight. Mean prepartum Hb and Hct level were 12.3 ± 1.1 g/dl and 36.9 ± 2.7%, respectively, with no significant difference between the groups. Mean postpartum HB and Hct decline was 1.3 ± 0.8 g/dl and 3.7 ± 2.3%, respectively, with no difference between the groups. In multivariable analysis after adjusting for parity, pre-pregnancy BMI, labor induction, episiotomy or perineal tears and neonatal birthweight, oxytocin regimen was not associated with any difference in hematological measurements.

CONCLUSION

Postpartum Hb and Hct decline was usually minor following vaginal deliveries, and was not affected by postpartum oxytocin regimen.

Estimating blood loss during cesarean delivery: A comparison of methods

Objectives

Obstetrical hemorrhage contributes significantly to maternal morbidity and mortality. Assessment of blood loss while undergoing cesarean sections (CS) is essential in lowering the morbidity and mortality, however this amount is commonly underestimated by the surgeon and probably the anesthetist too.

Methods

This study addresses this issue by comparing three separate ways of assessing blood loss during cesarean sections. For each of 97 full-term pregnant women undergoing elective CS, blood loss was measured by the following: visual estimation by both the obstetrician and the anesthetist, weighing surgical pads pre operatively and post operatively and by calculations (multiplying the difference of pre-operative and postoperative hemoglobin values by the patient's estimated blood volume).

Results

The results of this study indicated that the lowest estimated value for blood loss came from visual estimation, while the highest value came from the mathematical formula. Anesthetists were more accurate in their visual estimation of blood loss than were obstetricians.

Conclusion

This study found the amount of blood loss during CS to be overestimated by the mathematical calculation and underestimated by obstetricians. However, the estimate given by anesthetists was close to that obtained by weighing pads. This underscores the need for more accurate methods of blood loss estimation in cesarean sections to be adopted.

Workshop on Blood Loss Quantification in Obstetrics: Improving Medical Student Learning through Clinical Simulation

PURPOSE

To assess whether a clinical simulation-based obstetric blood loss quantification workshop for medical undergraduate trainees improves theoretical-practical knowledge, along with self-assurance and self-confidence.

METHODS

This was a quasi-experimental pre-post learning study conducted at the Gynaecology and Obstetrics Unit of the Hospital Gregorio Marañón, Madrid, Spain. Participants were volunteer students in their fourth year of a 6-year degree course in Medicine. The study period was divided into the stages: pre-workshop, intra-workshop, 2 weeks post-workshop and 6 months post-workshop. In the pre-workshop stage, students completed a brief online course in preparation for the workshop. The effectiveness of the workshop was assessed through multiple choice tests and self-administered questionnaires. Data were compared between time-points using statistical tests for paired samples.

RESULTS

Of the 142 students invited (age 21.94 ± 3.12 years), 138 accepted the offer of the workshop (97.2%), and 85.4% had no experience in managing blood loss. Between the stages pre- and 2 weeks post-workshop, significant improvements were observed in theoretical-practical knowledge (μ = 1.109), self-assurance and self-confidence. At the 6 months post-workshop stage, theoretical-practical knowledge diminished compared with 2 weeks post-workshop, returning to pre-workshop levels, while self-assurance and confidence failed to vary significantly in the longer term.

CONCLUSIONS

The obstetric workshop improved theoretical-practical knowledge and the self-assurance and confidence of the medical students. Results 2 weeks post-workshop were maintained up until 6 months after the training intervention. The clinical simulation-based workshop was perceived by the students as useful and necessary.

Recurrence of postpartum hemorrhage, maternal and paternal contribution, and the effect of offspring birthweight and sex: a population-based cohort study

Purpose

This study examines individual aggregation of postpartum hemorrhage (PPH), paternal contribution and how offspring birthweight and sex influence recurrence of PPH. Further, we wanted to estimate the proportion of PPH cases attributable to a history of PPH or current birthweight.

Methods

We studied all singleton births in Norway from 1967 to 2017 using data from Norwegian medical and administrational registries. Subsequent births in the parents were linked. Multilevel logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CI) for PPH defined as blood loss > 500 ml, blood loss > 1500 ml, or the need for blood transfusion in parous women. Main exposures were previous PPH, high birthweight, and fetal sex. We calculated adjusted population attributable fractions for previous PPH and current high birthweight.

Results

Mothers with a history of PPH had three- and sixfold higher risks of PPH in their second and third deliveries, respectively (adjusted OR 2.9; 95% CI 2.9–3.0 and 6.0; 5.5–6.6). Severe PPH (> 1500 ml) had the highest risk of recurrence. The paternal contribution to recurrence of PPH in deliveries with two different mothers was weak, but significant. If the neonate was male, the risk of PPH was reduced. A history of PPH or birthweight ≥ 4000 g each accounted for 15% of the total number of PPH cases.

Conclusion

A history of PPH and current birthweight exerted strong effects at both the individual and population levels. Recurrence risk was highest for severe PPH. Occurrence and recurrence were lower in male fetuses, and the paternal influence was weak.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00404-021-06374-3.

Risk of postpartum haemorrhage is associated with ethnicity: a cohort study of 981 801 births in England

OBJECTIVE

To determine the association between ethnic group and risk of postpartum haemorrhage in women giving birth.

DESIGN

Cohort study.

SETTING

Maternity units in England.

POPULATION OR SAMPLE

981 801 records of births between 1^st April 2015 and 31^st March 2017 in a national clinical database.

METHODS

Multivariable logistic regression analyses with multiple imputation to account for missing data and robust standard errors to account for clustering within hospitals.

MAIN OUTCOME MEASURES

Postpartum haemorrhage of 1500ml or more (PPH).

RESULTS

28 268 (2.9%) of births were complicated by PPH. Risks were higher in women from black (3.9%) and other (3.5%) ethnic backgrounds. Following adjustment for maternal and fetal characteristics, and care at birth, there was evidence of an increased risk of PPH in women from all ethnic minority groups, with the largest increase seen in black women (adjusted odds ratio 1.54 (1.45 to 1.63)). The increase in risk was robust to sensitivity analyses which included changing the outcome to PPH of 3000ml or more.

CONCLUSIONS

In England, women from ethnic minority backgrounds have an increased risk of PPH, when maternal, fetal and birth characteristics are taken into account. Factors contributing to this increased risk need further investigation. Perinatal care for women from ethnic minority backgrounds should focus on preventative measures to optimise maternal outcomes.

The effects of obstetric emergency team training on patient outcome: A systematic review and meta-analysis

INTRODUCTION

Little is known about the optimal simulation-based team training in obstetric emergencies. We aimed to review how simulation-based team training affects patient outcomes in obstetric emergencies.

MATERIAL AND METHODS

Search Strategy: MEDLINE, Embase, Cochrane Library, and Cochrane Central Register of Controlled Trials were searched up to and including May 15, 2021.

SELECTION CRITERIA

randomized controlled trials (RCTs) and cohort studies on obstetric teams in high-resource settings comparing the effect of simulation-based obstetric emergency team training with no training on the risk of Apgar scores less than 7 at 5 min, neonatal hypoxic ischemic encephalopathy, severe postpartum hemorrhage, blood transfusion of four or more units, and delay of emergency cesarean section by more than 30 min.

DATA COLLECTION AND ANALYSIS

The included studies were assessed using PRISMA, EPCO, and GRADE.

RESULTS

We found 21 studies, four RCTs and 17 cohort studies, evaluating patient outcomes after obstetric team training compared with no training. Annual obstetric emergency team training may reduce brachial plexus injury (six cohort studies: odds ratio [OR] 0.47, 95% CI 0.33-0.68; one RCT: OR 1.30, 95 CI% 0.39-4.33, low certainty evidence) and suggest a positive effect; but it was not significant on Apgar score below 7 at 5 min (three cohort studies: OR 0.77, 95% CI 0.51-1.19; two RCT: OR 0.87, 95% CI 0.72-1.05, moderate certainty evidence). The effect was unclear for hypoxic ischemic encephalopathy, umbilical prolapse, decision to birth interval in emergency cesarean section, and for severe postpartum hemorrhage. Studies with in situ multi-professional simulation-based training demonstrated the best effect.

CONCLUSIONS

Emerging evidence suggests an effect of obstetric team training on obstetric outcomes, but conflicting results call for controlled trials targeted to identify the optimal methodology for effective team training.

Incidence and Risk Factors of Postpartum Hemorrhage in China: A Multicenter Retrospective Study

Background: Postpartum hemorrhage (PPH) is a leading cause of maternal morbidity and mortality worldwide but the incidence and its risk factors in China is limited. The objective of this study is to investigate the incidence and the risk factors of PPH in Chinese women.

Methods: A multi-center retrospective study of pregnant women at ≥28 weeks of gestation was conducted. Logistic regression was used to identify potential risk factors of PPH and receiver operating characteristic curve was used to evaluate the predictive performance of the identified risk factors. Subgroup analysis focusing on the number of fetus and the mode of delivery was conducted.

Results: A total of 99,253 pregnant women were enrolled and 804 (0.81%) experienced PPH. The subgroup analysis revealed that the incidence of PPH was 0.75, 2.65, 1.40, and 0.31% in singletons, twin pregnancies, cesarean sections, and vaginal deliveries, respectively. Placenta previa and placenta accreta were the predominant risk factors of PPH in the overall population and all subgroups. A twin pregnancy was a risk factor for PPH regardless of the mode of delivery. Obesity, and multiparity were risk factors for PPH in both singletons and cesarean section cases, but the latter predicted a reduced probability of PPH in vaginal deliveries. Macrosomia was associated with increased risk of PPH in singletons or vaginal deliveries. In women who delivered vaginally, preeclampsia was associated with a higher risk of PPH. The areas under the curve for the overall cohort, singletons, twin pregnancies, cesarean section cases, and vaginal deliveries were 0.832 (95% confidence interval [CI] 0.813–0.851), 0.824 (95% CI 0.803–0.845), 0.686 (95% CI 0.617–0.755), 0.854 (95% CI 0.834–0.874), and 0.690 (95% CI 0.646–0.735), respectively.

Conclusions: The risk factors of PPH varied slightly based on the number of fetuses and the mode of delivery, while placenta previa and placenta accreta were the two major risk factors. A combination of the identified risk factors yielded a satisfactory predictive performance in determining PPH in the overall cohort, singletons pregnancies, and women who delivered by cesarean section, whereas the performance was moderate in twin pregnancies and in women delivering vaginally.

Postpartum haemorrhage and associated factors among mothers who gave birth in South Gondar Zone public health facilities, Ethiopia: a cross-sectional study

BACKGROUND

Postpartum haemorrhage is one of the direct and the leading causes of maternal morbidity and mortality. There are many risk factors of postpartum haemorrhage, which vary in different settings. Therefore, the purpose of this study was to assess postpartum haemorrhage and associated factors among mothers who gave birth in public health facilities.

METHODS

A cross-sectional study was employed from 17 November 2019 to 15 February 2020. The study participants were selected using a systematic sampling technique. The data were entered and cleaned using EpiData V.3.1 then exported to SPSS V.20 for analysis. Factors associated with postpartum haemorrhage were selected for multiple logistic regression at the probability value (p value) of less than 0.2 in the χ² analysis. Statistically significant associated factors were identified at probability value (p value) less than 0.05 and adjusted OR (AOR) with a 95% CI.

RESULTS

The mean age of participants was 31.3 (SD ±5.7) years. This study found that the prevalence of postpartum haemorrhage was 13.6% (67). Age of participants (AOR 12.5, 95% CI 4.0 to 38.6), disrespectful maternity care (AOR 8.4, 95% CI 3.2 to 22.0), labour induction and augmentation (AOR 6.97, 95% CI 2.34 to 20.8), the prolonged second stage of labour (AOR 9.9, 95% CI 2.6 to 37.1) and no antenatal care visit (AOR 10.1, 95% CI 3.4 to 29.7) were statistically significant associated factors of postpartum haemorrhage.

CONCLUSIONS

The prevalence of postpartum haemorrhage is high. The age of the participants, disrespectful maternity care, labour induction and augmentation, the prolonged second stage of labour and no antenatal care visit were independent predictors of postpartum haemorrhage.

Automated Quantification of Blood Loss versus Visual Estimation in 274 Vaginal Deliveries

OBJECTIVE

The aim of the study is to compare quantified blood loss measurement (QBL) using an automated system (Triton QBL, Menlo Park, CA) with visual blood loss estimation (EBL) during vaginal delivery.

STUDY DESIGN

During 274 vaginal deliveries, both QBL and EBL were determined. The automated system batch weighs blood containing sponges, towels, pads, and other supplies and automatically subtracts their dry weights and also the measured amount of amniotic fluid. Each method was performed independently, and clinicians were blinded to the device's results.

RESULTS

Median QBL (339 mL [217-515]) was significantly greater than median EBL (300 mL [200-350]; p < 0.0001). The Pearson's correlation between EBL and QBL was poor (r = 0.520) and the Bland-Altman's limits of agreement were wide (>900 mL). QBL measured blood loss >500 mL occurred in 73 (26.6%) patients compared with 14 (5.1%) patients using visual estimation (p < 0.0001). QBL ≥  1,000 mL was recorded in 11 patients (4.0%), whereas only one patient had an EBL blood loss of 1,000 mL and none had EBL >1,000 mL (p = 0.002).

CONCLUSION

Automated QBL recognizes more patients with excessive blood loss than visual estimation. To realize the value of QBL, clinicians must accept the inadequacy of visual estimation and implement protocols based on QBL values. Further studies of clinical outcomes related to QBL are needed.

KEY POINTS

· QBL detects hemorrhage more frequently than visual estimation.. · Median QBL is significantly greater than median EBL.. · There is poor agreement between QBL and EBL..

Routine Postoperative Chemistry Panels Are Not Necessary for Most Total Joint Arthroplasty Patients

BACKGROUND

The routine use of traditional chemistry-7 (chem-7) laboratory tests following total joint arthroplasty (TJA) has been called into question with the advent of short-stay procedures. Our objective was to determine the incidence, risk factors, and clinical interventions associated with inpatient abnormal routine postoperative chem-7 panels.

METHODS

From 2015 to 2017, 3,162 patients underwent a total of 3,721 TJA procedures, including primary total hip arthroplasty (THA) (n = 1,939; 52.1%) or primary total knee arthroplasty (TKA) (n = 1,782; 47.9%). Patients underwent routine preoperative and postoperative chem-7 testing. Clinical interventions were identified. With use of mixed-effects multivariate logistic regression, potential risk factors for abnormal chemistry panel values (including preoperative chem-7 results, type of surgery, age, sex, race, comorbidities, American Society of Anesthesiologists [ASA] score, and medications) were analyzed.

RESULTS

The rates of abnormal preoperative laboratory results were 3.4% for sodium (Na+), 7.4% for potassium (K+), 15.8% for blood urea nitrogen (BUN), and 26.4% for creatinine (Cr). The incidence of abnormal postoperative results was low for K+ (9.7%) and higher for Na+ (25.6%), BUN (55.6%), and Cr (27.9%). Preoperative abnormal laboratory results were a significant predictor of a postoperative abnormality for Na+ (odds ratio [OR] = 2.15; 95% confidence interval [CI] = 1.82 to 2.54), K+ (OR = 4.22; 95% CI = 3.03 to 5.88), and Cr (OR = 3.00; 95% CI = 2.45 to 3.68). Bilateral TJA was associated with increased odds of abnormal postoperative Na+ (OR = 1.56; 95% CI = 1.44 to 1.68). Renal disease was associated with increased odds of abnormal postoperative Cr (OR = 15.21; 95% CI = 5.67 to 40.77). Patients taking loop diuretics had increased odds of abnormal postoperative K+ (OR = 2.10; 95% CI = 1.42 to 3.11) and Cr (OR = 2.28; 95% CI = 1.56 to 3.33). Regarding intervention, 6.7% of hypokalemic patients received potassium chloride (KCl) fluid/tablets. Forty percent of hyponatremic patients received sodium chloride (NaCl) fluid/tablets. The electrolyte-related medicine consultation rate was 0.3% (13 of 3,721).

CONCLUSIONS

On the basis of our findings, we recommend postoperative chem-7 testing for patients with an abnormal preoperative laboratory result (Na+, K+, BUN, Cr), preexisting renal disease, bilateral TJA, and prescribed angiotensin-converting enzyme inhibitors (ACE), angiotensin II receptor blockers (ARB), and diuretics.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Reduction in massive postpartum haemorrhage and red blood cell transfusion during a national quality improvement project, Obstetric Bleeding Strategy for Wales, OBS Cymru: an observational study

Background

Postpartum haemorrhage (PPH) is a major cause of maternal morbidity and mortality and its incidence is increasing in many countries despite management guidelines. A national quality improvement programme called the Obstetric Bleeding Strategy for Wales (OBS Cymru) was introduced in all obstetric units in Wales. The aim was to reduce moderate PPH (1000 mL) progressing to massive PPH (> 2500 mL) and the need for red cell transfusion.

Methods

A PPH care bundle was introduced into all 12 obstetric units in Wales included all women giving birth in 2017 and 2018 (n = 61,094). The care bundle prompted: universal risk assessment, quantitative measurement of blood loss after all deliveries (as opposed to visual estimation), structured escalation to senior clinicians and point-of-care viscoelastometric-guided early fibrinogen replacement. Data were submitted by each obstetric unit to a national database. Outcome measures were incidence of massive PPH (> 2500 mL) and red cell transfusion. Analysis was performed using linear regression of the all Wales monthly data.

Results

Uptake of the intervention was good: quantitative blood loss measurement and risk assessment increased to 98.1 and 64.5% of all PPH > 1000 mL, whilst ROTEM use for PPH > 1500 mL increased to 68.2%. Massive PPH decreased by 1.10 (95% CI 0.28 to 1.92) per 1000 maternities per year (P = 0.011). Fewer women progressed from moderate to massive PPH in the last 6 months, 74/1490 (5.0%), than in the first 6 months, 97/1386 (7.0%), (P = 0.021). Units of red cells transfused decreased by 7.4 (95% CI 1.6 to 13.2) per 1000 maternities per year (P = 0.015). Red cells were transfused to 350/15204 (2.3%) and 268/15150 (1.8%) (P = 0.001) in the first and last 6 months, respectively. There was no increase in the number of women with lowest haemoglobin below 80 g/L during this time period. Infusions of fresh frozen plasma fell and there was no increase in the number of women with haemostatic impairment.

Conclusions

The OBS Cymru care bundle was feasible to implement and associated with progressive, clinically significant improvements in outcomes for PPH across Wales. It is applicable across obstetric units of widely varying size, complexity and staff mixes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03853-y.

A Prospective Comparison of Three Strategies for Evaluating Blood Loss in Transurethral Resection of the Prostate

Objective

The aim of the current investigation is to develop a new strategy for evaluating blood loss in the process of transurethral resection of the prostate (TURP).

Methods

318 patients diagnosed with benign prostatic hyperplasia (BPH) that need TURP were enrolled in this study. Hospitalization information including age, height, weight, surgery time, prostate volume, hemoglobin (Hb) concentration, hematocrit (HCT) percentage, and red blood cell count (RBC) was evaluated for each patient. All statistical analysis drawing were conducted using R software.

Results

Three methods were employed for calculating blood loss in TURP. Results from a new method display 0 missing value and got higher confidence (0 of 318, Poisson distribution, P < 0.001) compared with blood loss calculated with hemoglobin concentration (20.44%) and hematocrit percentage (19.18%). Also, the new method demonstrated narrow range (0.03~270.03 ml) and approximate normal distribution compared with blood loss calculated with hemoglobin concentration and hematocrit percentage. More importantly, the new method explained positive correlation with prostate volume (R ² = 0.138, P < 0.001) and also surgery lasting time (R ² = 0.193, P < 0.001).

Conclusion

Methods developed for calculating blood loss in TURP in the current study displayed more accurate and reasonable evaluation of bleeding, which can guide the transfusion blood for patients.

Maternal and neonatal bleeding complications in relation to peripartum management in hemophilia carriers: A systematic review

Currently, there is no consensus on the optimal management to prevent postpartum hemorrhage (PPH) in hemophilia carriers. We aimed to evaluate peripartum management strategies in relation to maternal and neonatal bleeding outcomes by performing an extensive database search up to August 2020. Seventeen case-reports/series and 11 cohort studies were identified of overall 'poor' quality describing 502 deliveries. The PPH incidence in the individual patient data was 63%; 44% for those women receiving prophylaxis to correct coagulation and 77% for those without (OR 0.23, CI 0.09-0.58) and in cohort data 20.3% (26.8% (11/41) vs. 19.4% (55/284) (OR: 1.53, 95% CI: 0.72-3.24), respectively. Peripartum management strategies mostly consisted of clotting factor concentrates, rarely of desmopressin or plasma. Tranexamic acid appears promising in preventing secondary PPH, but was not used consistently. Neonatal bleeding was described in 6 affected male neonates, mostly after instrumental delivery or emergency CS, but insufficient information was provided to reliably investigate neonatal outcome in relation to management. The high PPH risk seems apparent, at most mildly attenuated by prophylactic treatment. Prospective cohort studies are needed to determine the optimal perinatal management in hemophilia.

Retained placenta and postpartum hemorrhage: time is not everything

PURPOSE

Postpartum hemorrhage is the major cause of maternal mortality worldwide. Retained placenta accounts for nearly 20% of severe cases. We investigated the influence of the time factor and retained placenta etiology on postpartum hemorrhage dynamics.

METHODS

Our retrospective study analyzed a single-center cohort of 296 women with retained placenta. Blood loss was measured using a validated and accurate technique based on calibrated blood collection bags, backed by the post- vs pre-partum decrease in hemoglobin. We evaluated the relationship between these two blood loss parameters and the duration of the third stage of labor using Spearman rank correlation, followed by subgroup analysis stratified by third stage duration and retained placenta etiology.

RESULTS

Correlation analysis revealed no association between third stage duration and measured blood loss or decrease in hemoglobin. A shorter third stage (< 60 min) was associated with significantly increased uterine atony (p = 0.001) and need for blood transfusion (p = 0.006). Uterine atony was significantly associated with greater decrease in hemoglobin (p < 0.001), higher measured blood loss (p < 0.001), postpartum hemorrhage (p = 0.048), and need for blood transfusion (p < 0.001).

CONCLUSION

Postpartum blood loss does not correlate with third stage duration in women with retained placenta. Our results suggest that there is neither a safe time window preceding postpartum hemorrhage, nor justification for an early cut-off for manual removal of the placenta. The prompt detection of uterine atony and immediate prerequisites for manual removal of the placenta are key factors in the management of postpartum hemorrhage.

Accuracy of Blood Transfusion Records in a Population-based Perinatal Data Registry

BACKGROUND

Blood transfusion is frequently used as an indicator of severe maternal morbidity during pregnancy. However, few studies have examined its validity in population perinatal databases.

METHODS

We linked a perinatal database from British Columbia, Canada, with the province's Central Transfusion Registry for 2004-2015 deliveries. Using the Central Transfusion Registry records for red blood cell transfusion as the gold standard, we calculated the sensitivity, specificity, positive predictive value, and negative predictive value of the perinatal database variable for red blood cell transfusion, overall and by transfusion risk factor status. We used multivariable logistic regression to examine whether outcome misclassification altered the odds ratios for different transfusion risk factors.

RESULTS

Among 473,688 deliveries, 4,033 (8.5 per 1,000) had a red blood cell transfusion according to the Central Transfusion Registry. The sensitivity of the perinatal database transfusion variable was 72.3 [95% confidence interval (CI) = 72.2, 72.4]. Sensitivity differed according to the presence of many transfusion risk factors (e.g., 84.9% vs. 72.2% in deliveries with versus without uterine rupture). Odds ratios associated with some transfusion risk factors were exaggerated when the perinatal database transfusion variable was used to define the outcome instead of the Central Transfusion Registry variable, but 95% confidence intervals for these estimates overlapped.

CONCLUSION

Blood transfusion was documented with reasonable sensitivity in this large population perinatal database. However, validity varied according to risk factor status. Our findings enable researchers to better account for outcome misclassification in studies of obstetrical transfusion risk factors.

Can measuring blood loss at delivery reduce hemorrhage-related morbidity?

Quantitation of blood loss after vaginal and cesarean delivery has been advocated for the timely detection of postpartum hemorrhage and activation of protocols for resuscitation. Morbidity and mortality from postpartum hemorrhage is considered to be largely preventable and is attributed to delayed recognition with under-resuscitation or inappropriate resuscitation. Optimizing detection of postpartum hemorrhage through refining how blood loss is measured is therefore clinically relevant. In this review on quantitative blood loss for postpartum hemorrhage, recent advances in the methods used to quantitate blood loss will be reviewed, with a comparison of utility and precision for blood loss measurement after vaginal and cesarean delivery. Considerations for the implementation of a quantitative blood loss system on the labor and delivery unit, including its benefits and challenges, will be discussed. The existing evidence for impact of blood loss quantitation in obstetrics on hemorrhage-related morbidity will be delineated, along with knowledge gaps and future research priorities.

Current Challenges in the Peripartum Management of Women with von Willebrand Disease

For many women, pregnancy and childbirth represent their first major hemostatic challenges. Despite advancements in obstetric care, up to 2 to 5% of all deliveries are complicated by postpartum hemorrhage (PPH). To mitigate bleeding risk, physiological changes occur in pregnancy, including increases in plasma von Willebrand factor (VWF) and factor VIII levels. For women with von Willebrand disease (VWD), these physiological alterations are blunted or absent. As a result, women with VWD have a heightened risk of PPH, both primary (in the first 24 hours) and secondary (>24 hours to 6 to 12 weeks postpartum). Pregnancy and delivery management for women with VWD should therefore be carefully coordinated as part of a multidisciplinary team approach. In the absence of large-scale clinical trials, the management of women with VWD during pregnancy is guided by expert consensus guidelines. Clinical practices internationally are not uniform, and areas of considerable clinical uncertainty exist. Traditional peripartum plasma VWF thresholds for hemostatic cover and therapeutic targets are currently under scrutiny, as PPH is not eliminated in women with VWD who receive replacement therapy. The benefit and optimal duration of postpartum tranexamic acid have yet to be defined, and standardized methods of quantification of blood loss at the time of delivery are currently lacking. In this article, we review the evidence base to date and explore the current clinical challenges in the management of pregnant women with VWD.

A review of postpartum hemorrhage in low-income countries and implications for strengthening health systems

Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and mortality worldwide. Disparities in PPH-associated survival between high and low-/middle-income countries reflect an imperative for low-resource countries to improve strategies for rapid diagnosis and treatment. A review of current PPH diagnosis, prevention, treatment, and access to care in low-income countries has been used to understand, extract, and report the challenges that public health systems face in trying to solve the marked global disparity in PPH outcomes. Improvement in PPH survival begins with holistic strengthening of each step along the continuum of care in health systems and should include performance feedback measures and quality-of-care research.

Risk factors for postpartum hemorrhage following cesarean delivery

OBJECTIVE

To identify risk factors for postpartum hemorrhage (PPH) following cesarean delivery (CD).

METHODS

A retrospective study of all women who underwent CD in a university-affiliated tertiary hospital (2014-15). PPH was defined as any of the following: clinical PPH (≥1000 ml estimated blood loss), hemoglobin (Hb) drop ≥3 g/dl (the difference between pre-CD Hb level within a 24 h prior to the delivery) and post-CD (nadir level during the first 72 h after CD)) or the need for blood products transfusion. The characteristics of women with PPH following CD were compared to a control group of those with CD without PPH.

RESULTS

Of the 15,564 deliveries during the study period, 3208 (20.6%) women met inclusion criteria, of them, 307 (9.6%) had PPH and 2901 (90.4%) served as controls. Women in the PPH group were younger (32.6 ± 5.3 vs. 33.5 ± 5.4, p = .006) and more often nulliparous (45.9% vs. 33.3%, p<.001) compared to the controls. However, there were no differences between the groups regarding the rate of multiple gestations, maternal diabetes mellitus, hypertensive disorders, polyhydramnios, and macrosomia. The rates of induction of labor (16.3% vs. 8.6%, p<.001) and urgent CD (47.9% vs. 32.0%, p<.001) were higher in the PPH group compared to the controls. In multivariate logistic regression, predictors for PPH following CD were (odds ratio, 95% confidence interval) urgent CS (1.57, 1.78-2.11, p = .002), CD duration (1.02, 1.01-1.03, p<.001), and the number of previous CDs (0.74, 0.62-0.90, p = .003).

CONCLUSIONS

In women undergoing cesarean section, urgent CD, the duration of the surgery, and the number of the previous CD are associated with the risk of PPH and should be taken into consideration during the postpartum assessment.

Accuracy of training blood volume quantification using a visual estimation tool

BACKGROUND

We investigated whether the use of a specially designed visual estimation tool may improve accuracy in quantifying blood volumes related to surface spreading.

METHODS

A prospective, paired-control, single-blinded experimental study was performed at a medical university. Anesthesiologists and emergency medical personnel estimated various blood volumes on surfaces with varying absorptivity (carpet, towel, polyvinyl chloride, wooden flooring) in an experimental setting. We assessed the sensitivity of training blood volume quantification using a self-designed visual estimation tool by comparing the accuracy of visual blood volume estimations before and after practical training with the tool.

RESULTS

A total of 352 estimations by 44 participants were evaluated. Accurate estimations improved significantly from pre-training to post-training (P<0.05). The sensitivity of blood volume quantification was 33.0% after training with the visual estimation tool. Estimations did not depend on age, profession, gender or years of the estimator's professional experience.

CONCLUSIONS

Training with a visual estimation tool by professional rescuers can improve the estimation accuracy of blood volumes spread on surfaces with varying absorptivity.

"It's like a bus, going downhill, without a driver": A qualitative study of how postpartum haemorrhage is experienced by women, their birth partners, and healthcare professionals

PROBLEM

Postpartum haemorrhage [PPH] remains a major cause of maternal morbidity and mortality. Whilst low-resource settings bear the greatest burden of deaths, women live with associated morbidities in all healthcare settings. Limited data exists regarding the experience for women, their partners, or healthcare professionals [HCPs], affected by PPH.

AIM

To qualitatively investigate the experience of PPH, for women (n=9), birth partners (n=4), and HCPs (n=9) in an inner-city tertiary referral centre. To provide multi-faceted insight into PPH and improve understanding and future care practices.

METHODS

Participants were interviewed about their experiences within two weeks of a PPH. Data were analysed using thematic analysis.

FINDINGS

Four distinct, but related, themes were identified: 'Knowledge specific to PPH'; 'Effective and appropriate responses to PPH'; 'Communication of risk factors'; and 'Quantifying blood loss'; which collected around a central organising concept of 'Explaining the indescribable'.

DISCUSSION

PPH was viewed as a 'crisis-style emergency', generating respectful fear in HCPs, whilst women and partners had little-to-no prior knowledge. Specific PPH knowledge dictated HCPs' response and risk communication. PPH risks were typically linked to quantification of blood loss, assessment of which varied with acknowledged questionable accuracy. Women's and partners' confidence in HCPs' ability to deal with PPH was unquestionable. Non-verbal communication was highlighted, with HCP body language betraying professional confidence.

CONCLUSION

Information about blood loss during childbirth must be imparted in a sensitive, timely manner. Whilst training for HCPs results in effective PPH management, consideration should be given to their non-verbal cues and the impact of dealing with this stressful, 'everyday emergency'.

Hemoglobin drop following postpartum hemorrhage

Postpartum hemorrhage (PPH) is defined as blood loss of ≥ 500–1000 ml within 24 h after delivery. Yet, assessment of blood loss is imprecise. The present study aimed to profile the hemoglobin (Hb) drop after vaginal delivery with versus without PPH. This was a secondary analysis of a prospective cohort study of women who delivered vaginally. Women were included if complete blood counts (CBC) before and after delivery were taken until stabilization (N = 419). Women were categorized into the PPH group and controls, for whom post-delivery CBCs were performed due to indications unrelated to bleeding. The PPH patients were then classified as either overt or occult PPH (symptoms related to hypovolemia without overt bleeding) subgroups. The primary endpoint was mean Hb drop after delivery. One hundred and ten (26%) and 158 (38%) women presented with overt PPH or occult PPH, respectively; 151 (36%) women were included in the control group. Mean Hb decrease from baseline was 3.0 ± 1.6, 2.0 ± 1.4 and 0.9 ± 1.0 g/dl, respectively (p < 0.0001). In all groups, maximal rate of Hb decline was in the first 6–12 h postpartum and plateaued after 24–48 h. At 48 h post-delivery, 95% and 86% of women who had dropped to Hb ≤ 9.5 and < 7 g/dl, respectively, reached those thresholds. Taken together, an Hb decrease ≥ 2 g/dl was consistent with PPH diagnosis and should be followed for at least 48 h after delivery.

Prevention and treatment of postpartum hemorrhage: focus on hematological aspects of management

Postpartum hemorrhage (PPH) is the leading cause of global maternal mortality and accounts for approximately one-quarter of all maternal deaths worldwide. Prevention of excess maternal deaths requires a coordinated approach to prevention, early recognition, and intervention by a multidisciplinary team. Although some women have risk factors for PPH that can be identified during pregnancy or during labor or birth, most women with severe PPH do not have any risk factors. Therefore, all pregnant women must be considered to be at risk of PPH. Common causes include uterine atony, retained placenta, trauma to the genital tract or uterus, and coagulopathy. The pivotal role of fibrinogen and hyperfibrinolysis in the evolution and as a treatment target for PPH is increasingly recognized. Coagulopathy can be an early feature in PPH that may be unrecognized, as it can be present before massive transfusion has occurred. Identification of coagulopathy by viscoelastic point-of-care testing or conventional laboratory assays can be helpful in guiding management of PPH and preventing severe maternal outcomes.

Obstetric Hemorrhage Risk Associated with Novel COVID-19 Diagnosis from a Single-Institution Cohort in the United States

OBJECTIVE

The study aimed to compare the quantitative blood loss (QBL) and hemorrhage-related outcomes of pregnant women with and without a coronavirus disease 2019 (COVID-19) diagnosis.

STUDY DESIGN

This retrospective cohort study of all live deliveries at Boston Medical Center between April 1, 2020 and July 22, 2020 compares the outcomes of pregnant women with a laboratory-confirmed COVID-19 positive diagnosis and pregnant women without COVID-19. The primary outcomes are QBL and obstetric hemorrhage. The secondary outcomes analyzed were a maternal composite outcome that consisted of obstetric hemorrhage, telemetry-level (intermediate care unit) or intensive care unit, transfusion, length of stay greater than 5 days, or intraamniotic infection, and individual components of the maternal composite outcome. Groups were compared using Student's t-test, Chi-squared tests, or Fisher's exact. Logistic regression was used to adjust for confounding variables.

RESULTS

Of 813 women who delivered a live infant between April 1 and July 22, 2020, 53 women were diagnosed with COVID-19 on admission to the hospital. Women with a COVID-19 diagnosis at their time of delivery were significantly more likely to identify as a race other than white (p = 0.01), to deliver preterm (p = 0.05), to be diagnosed with preeclampsia with severe features (p < 0.01), and to require general anesthesia (p < 0.01). Women diagnosed with COVID-19 did not have a significantly higher QBL (p = 0.64). COVID-19 positive pregnant patients had no increased adjusted odds of obstetric hemorrhage (adjusted odds ratio [aOR]: 0.41, 95% confidence interval [CI]: 0.17-1.04) and no increased adjusted odds of the maternal morbidity composite (aOR: 0.98, 95% CI: 0.50-1.93) when compared with those without a diagnosis of COVID-19.

CONCLUSION

Pregnant women with COVID-19 diagnosis do not have increased risk for obstetric hemorrhage, increased QBL or risk of maternal morbidity compared with pregnant women without a COVID-19 diagnosis. Further research is needed to describe the impact of a COVID-19 diagnosis on maternal hematologic physiology and pregnancy outcomes.

KEY POINTS

· Information about blood loss associated with peripartum COVID-19 is limited.. · COVID-19 diagnosis is not associated with increase in obstetric hemorrhage.. · COVID-19 diagnosis is not associated with increase in blood loss..

Blood type and postpartum hemorrhage by mode of delivery: A retrospective cohort study

OBJECTIVE

To assess the relationship between postpartum hemorrhage and ABO blood type for vaginal delivery and cesarean delivery.

STUDY DESIGN

This is a retrospective cohort study of data abstracted from the PeriBank database regarding demographics and delivery outcomes. All live singleton deliveries from January 2011 until March 2018 were included in this study. Exclusion criteria were sickle cell disease and multiple gestations. Analyses were conducted separately for cesarean delivery and vaginal delivery. Quantitative variables were analyzed with analysis of variance testing and categorical variables with chi square testing. Significant demographic differences between groups were controlled for using multivariate logistical regression. The primary outcome was the rate of postpartum hemorrhage by blood type (A, B, AB, and O), defined as blood loss >500 mL in vaginal delivery and >1000 mL in cesarean delivery. 43,437 patients were screened and 32,023 women met inclusion criteria (22,484 vaginal deliveries (70.2%) and 9539 cesarean deliveries (29.8%)).

RESULTS

In the vaginal delivery group there were differences in age, parity, race, use of regional anesthesia, rate of induction of labor, and thrombocytopenia between blood types. In the cesarean delivery group, age, parity, and race were significantly different between blood types. There was no observed difference in the rate of postpartum hemorrhage by blood type for those who delivered via vaginal delivery when controlling for demographic differences (p = 0.2). In the cesarean delivery group, there was a significantly higher rate of postpartum hemorrhage in women with type O blood (5.2% type O vs 3.8% type A vs 4.4% type B vs 4.2% type AB, p = 0.035), including when controlling for demographic differences (p = 0.02). In both vaginal and cesarean delivery groups, there was no difference in rates of any of the secondary outcomes, including blood transfusion, hysterectomy, intrapartum dilation and curettage, and intensive care unit admission.

CONCLUSION

Although this study found no statistically significant difference in clinical outcomes between blood types, type O blood may be an additional risk factor to consider for postpartum hemorrhage at the time of cesarean delivery.

The association of shock index and haemoglobin variation with postpartum haemorrhage after vaginal delivery: a prospective cohort pilot study

INTRODUCTION

Shock index and continuous non-invasive haemoglobin monitoring (SpHb) have both been proposed for the timely recognition of postpartum haemorrhage (PPH). We sought to determine, in parallel, the association of each of shock index and SpHb with blood loss after vaginal delivery.

METHODS

Sixty-six women were recruited to this prospective observational study. Shock index and SpHb were recorded postpartum for 120 min. The association between each of shock index and SpHb with quantitative blood loss (QBL) at 30, 60 and 120 min postpartum was determined using linear mixed models. Area-under-the-receiver-operator-characteristic (AUROC) curves were constructed to evaluate the diagnostic ability of shock index and SpHb to detect PPH (defined as QBL ≥1000 mL).

RESULTS

Shock index trend was associated with QBL over the first 30 min (r=0.37, P=0.002), but not over 60 or 120 min. There was an association of SpHb trend with QBL over the first 30 min (P=0.06), but not over 60 min (r=-0.32, P=0.009) or 120 min (r=-0.26, P=0.03). Maximum shock index within 60 min correlated with QBL (r=0.54, P <0.001) and was a predictor of PPH (P=0.0012, AUROC 0.796). Maximum change in SpHb within 60 min negatively correlated with QBL (r=-0.4, P <0.001) and was a predictor of PPH (P=0.048, AUROC 0.761).

CONCLUSIONS

The trend of shock index and its peak values are associated with blood loss after vaginal delivery and are early indicators of PPH. Negative trend of SpHb is a late sign of PPH and has a weaker association with blood loss than shock index.

Preoperative Type and Screen is Unnecessary in Elective Anatomic Lung Resection and Esophagectomy

BACKGROUND

Preoperative type and screen (TS) is routinely performed before elective thoracic surgery. We sought to evaluate the utility of this practice by examining our institutional data related to intraoperative and postoperative transfusions for two common, complex procedures.

MATERIALS AND METHODS

A single-center, retrospective review of a prospective thoracic surgery database was performed. Patients who underwent consecutive elective anatomic lung resection (ALR) and esophagectomy from January 2015 to April 2018 were included. Perioperative characteristics between patients who received transfusion of packed red blood cells and those who did not were compared. The rates of emergent and nonemergent transfusions were evaluated. Cost data were derived from institutional charges and Centers for Medicare & Medicaid Services fee schedules.

RESULTS

Of 370 patients, 16 (4.3%) received a transfusion and four (1.1%) were deemed emergent by the surgeons and 0 (0%) by blood bank criteria. For ALR (n = 321), 13 (4.0%) received a transfusion, and four (1.2%) were emergent. For esophagectomies (n = 49), three (6.1%) received a transfusion, and none were emergent. Patients who underwent ALR requiring a transfusion had a lower preoperative hemoglobin (11.7 versus 13.4 gm/dL, P = 0.001), higher estimated blood loss (1325 versus 196 mL, P < 0.001), and longer operative time (291 versus 217 min, P = 0.003) than nontransfused patients. Based on current volumes, eliminating TS in these patients would save at least an estimated $60,100 per year.

CONCLUSIONS

Emergent transfusion in ALR and esophagectomy is rare. Routine preoperative TS is most likely unnecessary for these cases. These results will be used in a quality improvement initiative to change practice at our institution.

Prevention of postpartum hemorrhage

Postpartum hemorrhage is a leading cause of severe maternal morbidity and mortality worldwide and the United States. While the rates of maternal mortality attributable to hemorrhage are declining, severe maternal morbidity continues to be a growing problem. Efforts in recent years to more appropriately identify patients at risk, define significant hemorrhage, quantify blood loss, and standardize approaches to care in pregnancy and postpartum have led to an increasing preventability of PPH. We aim to review the most current recommendation for the prevention and effective management of obstetric hemorrhage.

Comparison of common perioperative blood loss estimation techniques: a systematic review and meta-analysis

Estimating intraoperative blood loss is one of the daily challenges for clinicians. Despite the knowledge of the inaccuracy of visual estimation by anaesthetists and surgeons, this is still the mainstay to estimate surgical blood loss. This review aims at highlighting the strengths and weaknesses of currently used measurement methods. A systematic review of studies on estimation of blood loss was carried out. Studies were included investigating the accuracy of techniques for quantifying blood loss in vivo and in vitro. We excluded nonhuman trials and studies using only monitoring parameters to estimate blood loss. A meta-analysis was performed to evaluate systematic measurement errors of the different methods. Only studies that were compared with a validated reference e.g. Haemoglobin extraction assay were included. 90 studies met the inclusion criteria for systematic review and were analyzed. Six studies were included in the meta-analysis, as only these were conducted with a validated reference. The mixed effect meta-analysis showed the highest correlation to the reference for colorimetric methods (0.93 95% CI 0.91–0.96), followed by gravimetric (0.77 95% CI 0.61–0.93) and finally visual methods (0.61 95% CI 0.40–0.82). The bias for estimated blood loss (ml) was lowest for colorimetric methods (57.59 95% CI 23.88–91.3) compared to the reference, followed by gravimetric (326.36 95% CI 201.65–450.86) and visual methods (456.51 95% CI 395.19–517.83). Of the many studies included, only a few were compared with a validated reference. The majority of the studies chose known imprecise procedures as the method of comparison. Colorimetric methods offer the highest degree of accuracy in blood loss estimation. Systems that use colorimetric techniques have a significant advantage in the real-time assessment of blood loss.

Towards a universal definition of postpartum hemorrhage: retrospective analysis of Chinese women after vaginal delivery or cesarean section: A case-control study

Postpartum hemorrhage (PPH) is a leading cause of maternal morbidity and mortality, yet it is inconsistently defined, preventing accurate estimation of its incidence and identification of risk factors. Here we began to explore a unified definition of PPH that may be valid for vaginal delivery and cesarean section.Medical records of women who underwent vaginal delivery or cesarean section at our tertiary medical center between January and December 2018 were retrospectively analyzed. Patients who delivered by each route were compared in terms of PPH incidence and risk factors depending on different blood loss cut-off values.A total of 560 vaginal deliveries and 393 cesarean sections were analyzed. Vaginal deliveries were associated with significantly greater blood loss based on change of hemoglobin level, but significantly lower blood loss based on clinical estimation. When PPH was defined as blood loss ≥500 ml based on change of hemoglobin level, its incidence was 57.7% for vaginal deliveries and 28.2% for cesarean sections. The corresponding incidences were 15.4% and 3.3% when PPH was defined as blood loss ≥1000 ml based on change of hemoglobin levels. Independent risk factors for PPH in vaginal deliveries were lateral perineotomy (OR 2.835, 95%CI 1.694-4.743), suturing by a junior physician (OR 3.456, 95%CI 2.005-5.956), and long time from delivery of placenta to return to the recovery room (OR 1.013, 95%CI 1.003-1.022). A risk factor for PPH in cesarean sections was a long time from delivery of the fetus until the end of the operation.PPH is a significantly underestimated obstetric problem, especially in vaginal deliveries. Regardless of delivery route, hemoglobin-based blood loss of 500 ml and 1000 ml may be useful, respectively, as early warning and diagnostic cut-off values.

The impact of foetal restrictions on mode of delivery in women with inherited bleeding disorders

OBJECTIVES

Management of pregnancy in women with congenital bleeding disorders (CBD) is challenging and requires understanding of risks conferred to both the mother and the foetus. Some elements of labour management are considered to increase the risk of neonatal bleeding and are not recommended for neonates at risk of a significant bleeding disorder. The impact of these restrictions on obstetric outcomes in women with CBD is unknown.

METHODS

We retrospectively reviewed obstetric outcomes in a large cohort of women with CBD attending a specialised obstetric/haematology antenatal clinic over a 6-year period.

RESULTS

Ninety-four pregnancies in 76 women with a wide variety of CBDs were assessed. Foetal precautions were recommended in the majority of cases (88%). Twenty (21.2%) were delivered by elective Caesarean section (CS), predominantly for obstetric indications. Of the 63 women who laboured with foetal precautions in place, 6 (10%) had a CS that was performed because of these precautions. There was no neonatal bleeding but primary postpartum haemorrhage (PPH) occurred in 12.2% of women.

CONCLUSIONS

These data show that foetal precautions in labour recommended for women with CBDs will influence mode of delivery in approximately 10% of cases. This is important information for counselling these women about labour and delivery.

Management of the third stage of labour: (for the Optimal Intrapartum Care series edited by Mercedes Bonet, Femi Oladapo and Metin Gülmezoglu)

The physiology of the third stage of labour is described. Active management reduces the risk of postpartum haemorrhage (PPH), due to the use of a uterotonic agent. Intramuscular Oxytocin 10 IU has the highest efficacy and lowest side effect profile, although ergometrine, carbetocin and misoprostol are also effective. The appropriate uterotonic in different settings such as home birth by unskilled attendants and at caesarean section is discussed. For the latter, there is less consensus on the optimal dose/route of oxytocin, this topic remaining on the research agenda. Delayed cord clamping enables transfusion of blood to the neonate and is recommended rather than early clamping. Controlled cord traction should only be performed by skilled birth attendants and confers minimal advantage in preventing retained placenta. The importance of early recognition of PPH, and preparedness, is emphasised. An approach to medical and surgical management of PPH is presented.

Blood Loss Estimation in Small Animals and Assessment of a Pictorial Tool to Improve Accuracy in a Global Population of Veterinary Anesthesia Staff

Visual estimation of blood loss is the most common form of evaluating intraoperative hemorrhage, and is also the most inaccurate. This study investigated the visual estimation accuracy of a global population of anesthesia staff and students as an initial estimation and also with the assistance of a pictorial guide. A voluntary, two-part, online, anonymous survey was distributed to members of two email databases with an interest in anesthesia, including students, nurses, interns, residents, general practitioners, and specialists. The survey consisted of visual and brief descriptive depictions of blood loss scenarios involving small animals, principally including images of common surgical items and receptacles containing a blood-like substance. Each participant estimated the blood volume (in mL) for each scenario twice, initially (Pre-Guide [PGD]) and then with the aid of a pictorial guide (With-Guide [WGD]). The pictorial guide used similar images labeled with corresponding volumes. Data was analyzed for normality with the Shapiro-Wilks test, corrected to absolute error and compared for statistical significance using the Wilcoxon signed-ranks test or the Kruskal-Wallis test as appropriate. The overall raw PGD phase median estimation error was−27 mL (range −99 to 248 mL). The PGD raw median error increased with scenario complexity. There were no differences between role, gender, experience, or country of origin. The overall median raw estimation error for the WGD phase was 13 mL (range −80 ml to 143 mL) (p = 0.0128). Visual blood loss estimation is inaccurate amongst veterinary anesthetists and associated staff, showing decreasing accuracy with increasing complexity. A pictorial guide improves the accuracy generally, and specifically for more complex scenarios which are likely to reflect the clinical situation.

Incidence of postpartum haemorrhage defined by quantitative blood loss measurement: a national cohort

BACKGROUND

Visual estimation of blood loss following delivery often under-reports actual bleed volume. To improve accuracy, quantitative blood loss measurement was introduced for all births in the 12 hospitals providing maternity care in Wales. This intervention was incorporated into a quality improvement programme (Obstetric Bleeding Strategy for Wales, OBS Cymru). We report the incidence of postpartum haemorrhage in Wales over a 1-year period using quantitative measurement.

METHODS

This prospective, consecutive cohort included all 31,341 women giving birth in Wales in 2017. Standardised training was cascaded to maternity staff in all 12 hospitals in Wales. The training comprised mock-scenarios, a video and team drills. Uptake of quantitative blood loss measurement was audited at each centre. Data on postpartum haemorrhage of > 1000 mL were collected and analysed according to mode of delivery. Data on blood loss for all maternities was from the NHS Wales Informatics Service.

RESULTS

Biannual audit data demonstrated an increase in quantitative measurement from 52.1 to 87.8% (P < 0.001). The incidence (95% confidence intervals, CI) of postpartum haemorrhage of > 1000 mL, > 1500 mL and > 2000 mL was 8.6% (8.3 to 8.9), 3.3% (3.1 to 3.5) and 1.3% (1.2 to 1.4), respectively compared to 5%, 2% and 0.8% in the year before OBS Cymru. The incidence (95% CI) of bleeds of > 1000 mL was similar across the 12 hospitals despite widely varied size, staffing levels and case mix, median (25th to 75th centile) 8.6% (7.8-9.6). The incidence of PPH varied with mode of delivery and was mean (95% CI) 4.9% (4.6-5.2) for unassisted vaginal deliveries, 18.4 (17.1-19.8) for instrumental vaginal deliveries, 8.5 (7.7-9.4) for elective caesarean section and 19.8 (18.6-21.0) for non-elective caesarean sections.

CONCLUSIONS

Quantitative measurement of blood loss is feasible in all hospitals providing maternity care and is associated with detection of higher rates of postpartum haemorrhage. These results have implications for the definition of abnormal blood loss after childbirth and for management and research of postpartum haemorrhage.