Abnormal obstetric shock index and associated factors among immediate postpartum women following vaginal delivery at a tertiary hospital in southwestern Uganda.

BACKGROUND: Early recognition of haemodynamic instability after birth and prompt interventions are necessary to reduce adverse maternal outcomes due to postpartum haemorrhage. Obstetric shock Index (OSI) has been recommended as a simple, accurate, reliable, and low-cost early diagnostic measure that identifies hemodynamically unstable women. OBJECTIVES: We determined the prevalence of abnormal obstetric shock index and associated factors among women in the immediate postpartum period following vaginal delivery at Mbarara Regional Referral Hospital (MRRH) in southwestern Uganda. METHODS: We conducted a cross-sectional study at the labour suite and postnatal ward of MRRH from January 2022 to April 2022. We systematically sampled women who had delivered vaginally, and measured their blood pressures and pulse rates at 1 h postpartum. We excluded mothers with hypertensive disorders of pregnancy. Sociodemographic, medical and obstetric data were obtained through interviewer-administered questionnaires. The prevalence of abnormal OSI was the proportion of participants with an OSI ≥ 0.9 (calculated as the pulse rate divided by the systolic BP). Logistic regression analysis was used to determine associations between abnormal OSI and independent variables. RESULTS: We enrolled 427 women with a mean age of 25.66 ± 5.30 years. Of these, 83 (19.44%), 95% CI (15.79-23.52) had an abnormal obstetric shock index. Being referred [aPR 1.94, 95% CI (1.31-2.88), p = 0.001], having had antepartum haemorrhage [aPR 2.63, 95% CI (1.26-5.73), p = 0.010] and having a visually estimated blood loss > 200 mls [aPR 1.59, 95% CI (1.08-2.33), p = 0.018] were significantly associated with abnormal OSI. CONCLUSION: Approximately one in every five women who delivered vaginally at MRRH during the study period had an abnormal OSI. We recommend that clinicians have a high index of suspicion for haemodynamic instability among women in the immediate postpartum period. Mothers who are referred in from other facilities, those that get antepartum haemorrhage and those with estimated blood loss > 200mls should be prioritized for close monitoring. It should be noted that the study was not powered to study the factors associated with AOSI and therefore the analysis for factors associated should be considered exploratory.

Utilidad del índice de choque como valor predictivo para el requerimiento de trasfusión en hemorragia obstétrica / Utility of the shock index in obstetric hemorrhage as a predictive value for the transfusion requirement

Resumen Objetivo: Determinar el punto de corte del índice de choque obstétrico asociado con trasfusión masiva en mujeres con hemorragia obstétrica. Materiales y métodos: Estudio retrospectivo, transversal y analítico efectuado con base en la revisión de los expedientes clínicos de pacientes que ingresaron a la unidad de cuidados intensivos. Cálculo del índice de choque obstétrico al momento del diagnóstico de hemorragia obstétrica. Análisis de los signos vitales, gasometría, tipo de componentes sanguíneos trasfundidos y cantidad de líquidos administrados. Resultados: Se incluyeron 105 pacientes con hemorragia obstétrica; en 65 (61%) el resultado del índice de choque fue ≥ 0.9, de éstas 38 (58%) requirieron trasfusión masiva. El índice de choque obstétrico ≥ 0.9 se asoció, significativamente, con trasfusión masiva (p < 0.001). La pérdida sanguínea fue de 3000 mL (RIC 2000 mL) en pacientes con índice de choque obstétrico ≥ 0.9 vs 2500 mL (RIC 1000 mL) en pacientes con índice de choque obstétrico < 0.9 (p = 0.04). Las mujeres con índice de choque obstétrico ≥ 0.9 mostraron mayor requerimiento de trasfusión de concentrados globulares (p = 0.03) y plaquetarios (p = 0.01). Conclusiones: Un índice de choque obstétrico ≥ 0.9 se asoció con altos requerimientos de trasfusión sanguínea y mayor incidencia de eventos adversos graves, por lo que se recomienda este valor como el punto de corte para predicción de la necesidad de trasfusión masiva.

Abstract Objective: To determine the cut-off point of obstetric shock index associated with massive transfusion in women with obstetric hemorrhage. Materials and methods: We designed a cross-sectional study in women who were admitted to the intensive care unit. The obstetric shock index was calculated at the time of the diagnosis of obstetric hemorrhage. We analyzed vital signs, arterial blood gas, loss of blood, fluid replacement and transfused blood products. Results: One hundred and five women with obstetric bleeding were included, in 65 (61%) the obstetric shock index was ≥ 0.9, of whom 38 (58%) needed massive transfusion. Obstetric shock index ≥ 0.9 was significantly associated with massive transfusion (p < 0.001). The blood loss was of 3000 mL (RIC 2000 mL) in the patients with obstetric shock index ≥ 0.9 compared to 2500 mL (RIC 1000 mL) in patients with obstetric shock index < 0.9 (p = 0.04). Women with obstetric shock index ≥ 0.9 showed more significant requirement of transfusion of package red blood (p = 0.03) and platelets (p = 0.01). Conclusions: An obstetric shock index ≥0.9 was associated with high transfusión requirements and a higher incidence of serious adverse events, this value is recommended as the cut-off point for predicting the need for massive transfusion.

An update on the risk factors for and management of obstetric haemorrhage.

Obstetric haemorrhage is associated with increased risk of serious maternal morbidity and mortality. Postpartum haemorrhage is the commonest form of obstetric haemorrhage, and worldwide, a woman dies due to massive postpartum haemorrhage approximately every 4 min. In addition, many experience serious morbidity such as multi-organ failure, complications of multiple blood transfusions, peripartum hysterectomy and unintended damage to pelvic organs, loss of fertility and psychological sequelae, including posttraumatic stress disorders. Anticipation of massive postpartum haemorrhage, prompt recognition of the cause and institution of timely and appropriate measures to control bleeding and replacement of the lost blood volume and restoration of oxygen carrying capacity (i.e. haemoglobin) and correction of the 'washout phenomenon' leading to coagulopathy will help save lives. Obstetric shock index may help in avoidance of underestimation of blood loss and the use of tranexamic acid, oxytocics and timely peripartum hysterectomy, if appropriate, will help save lives. Triple P procedure has been recently developed as the conservative surgical alternative for women with abnormal invasion of the placenta and has been shown to significantly reduce the blood loss and to reduce inpatient stay.

Use of the "obstetric shock index" as an adjunct in identifying significant blood loss in patients with massive postpartum hemorrhage.

OBJECTIVE: To establish the normal range for the "obstetric shock index" (OSI) after birth and to determine its usefulness as an aid to estimate blood loss in postpartum hemorrhage (PPH). METHODS: A retrospective case-control analysis was conducted involving pregnant women admitted to St Georges Hospital for delivery: 50 with no PPH (control group) and 50 with massive PPH (>30% loss of blood volume; case group). The OSI was calculated at 10 and 30 minutes from PPH onset. RESULTS: Mean OSI in the control group at 10 and 30 minutes was 0.74 (range, 0.4-1.1) and 0.76 (range, 0.5-1.1), respectively. In the case group, mean OSI at 10 and 30 minutes was 0.91 (range, 0.4-1.5) and 0.90 (range, 0.5-1.4), respectively, with 64% requiring blood products. In the case group, 89% of women with an OSI of 1.1 or more at 10 minutes required transfusion; 75% with an OSI of 1.1 or more at 30 minutes required transfusion. CONCLUSION: We recommend that the normal OSI range should be 0.7-0.9. An OSI of more than 1 seems to be a useful adjunct in estimating blood loss in cases of massive PPH and in predicting the need for blood and blood products.