Obstetric hemorrhage and shock management: Using the low technology Non-pneumatic Anti-Shock Garment in Nigerian and Egyptian tertiary care facilities

Background: Obstetric hemorrhage is the leading cause of maternal mortality globally. The Non-pneumatic Anti-Shock Garment (NASG) is a low-technology, first-aid compression device which, when added to standard hypovolemic shock protocols, may improve outcomes for women with hypovolemic shock secondary to obstetric hemorrhage in tertiary facilities in low-resource settings.Methods: This study employed a pre-intervention/intervention design in four facilities in Nigeria and two in Egypt. Primary outcomes were measured mean and median blood loss, severe end-organ failure morbidity (renal failure, pulmonary failure, cardiac failure, or CNS dysfunctions), mortality, and emergency hysterectomy for 1442 women with ≥750 mL blood loss and at least one sign of hemodynamic instability. Comparisons of outcomes by study phase were assessed with rank sum tests, relative risks (RR), number needed to treat for benefit (NNTb), and multiple logistic regression.Results: Women in the NASG phase (n = 835) were in worse condition on study entry, 38.5% with mean arterial pressure <60 mmHg vs. 29.9% in the pre-intervention phase (p = 0.001). Despite this, negative outcomes were significantly reduced in the NASG phase: mean measured blood loss decreased from 444 mL to 240 mL (p < 0.001), maternal mortality decreased from 6.3% to 3.5% (RR 0.56, 95% CI 0.35-0.89), severe morbidities from 3.7% to 0.7% (RR 0.20, 95% CI 0.08-0.50), and emergency hysterectomy from 8.9% to 4.0% (RR 0.44, 0.23-0.86). In multiple logistic regression, there was a 55% reduced odds of mortality during the NASG phase (aOR 0.45, 0.27-0.77). The NNTb to prevent either mortality or severe morbidity was 18 (12-36).Conclusion: Adding the NASG to standard shock and hemorrhage management may significantly improve maternal outcomes from hypovolemic shock secondary to obstetric hemorrhage at tertiary care facilities in low-resource settings. © 2010 Miller et al; licensee BioMed Central Ltd. The studies were approved by Institutional Review Boards at the University of California, San Francisco (UCSF), the National Reproductive Health Research Committee of the Nigerian Federal Ministry of Health, the El Galaa Maternity Teaching Hospital and Assiut University Women's Health Center. The four sites selected from Nigeria were tertiary level teaching facilities, with 1,250-10,000 deliveries annually. The eight other facilities that were included in the project in Nigeria were implementation/intervention sites only and did not have a pre-intervention phase; therefore their data were not used in this analysis. The sites in Egypt comprised two tertiary teaching facilities, which had combined 31,990 deliveries in the pre-intervention and 31,176 deliveries in the NASG phase. The methods of the studies have been described in more detail elsewhere [5,7]. Briefly, in both countries, non-randomized intervention studies with a pre-intervention phase for controls were conducted. Women with hypovolemic shock secondary to obstetric hemorrhage from any etiology were eligible for enrollment if they had an estimated blood loss of ≥750 mL and one or more clinical signs of hypovolemic shock (systolic blood pressure [SBP] <100 mmHg and/or pulse >100 beats per minute [BPM]). Women were eligible regardless if they began to hemorrhage outside the facility and were transferred in, or began to hemorrhage in the facility. All etiologies of obstetric or pregnancy-related hemorrhage were included: complications of abortion, ectopic pregnancy, trophoblastic disease of pregnancy, problems of placentation, ruptured uterus, abruption, uterine atony, and lacerations. Women with ante-partum hemorrhage >24 weeks with a living fetus (based on presence of fetal heart tones) were excluded. During the pre-intervention phase in all facilities, women were managed with a standardized, evidence-based hemorrhage and shock protocol [5]; the intervention phase included the NASG into this protocol. The standardized protocol for both phases included: administration of oxygen, IV crystalloid fluids (>1500 mL in the first hour), and establishing the etiology of the hemorrhage. If the hemorrhage was due to uterine atony, uterotonics were administered, including: oxytocin, methergine, and misoprostol, and uterine massage or bimanual compression was performed. Depending on the source of the bleeding, the protocol included repair of lacerations, vaginal procedures such as manual vacuum aspiration or curettage to remove retained products and manual removal of retained placenta. Exploratory laparotomy was conducted and procedures performed, such as a salpingectomy for a ruptured ectopic, repair of a ruptured uterus, or an emergency hysterectomy. The protocol included laboratory investigations, such as complete blood count, creatinine, type and cross matching, and tests to rule out coagulopathies. Urine output was measured using either a Foley to a calibrated drainage bag or a straight catheter to a graduated collection bottle. Finally, the protocol called for a blood transfusion for all women with signs of shock. Blood loss after study entry in both phases was measured using a closed-end, calibrated, plastic blood collection drape (BRASSS-V Fixable Drape™ Madurai, India). If the woman required a vaginal procedure, the NASG was left completely in place. If she required a laparotomy, the abdominal and pelvic segments were opened immediately prior to making the incision, and then replaced when the surgery was completed. Staff in the facilities were trained in the standardized protocol, blood collection and measurement, NASG use, and completion of data collection forms. Definitions: For the purpose of the study, mortality refers to the death of a woman who was pregnant, post-partum or post abortion within the period of time of hospitalization for hemorrhage. Following the definition by Mantel et al.[10] severe maternal morbidities were defined as organ system dysfunctions related to severe obstetric hemorrhage: acute respiratory distress syndrome (impairment of respiratory function needing ventilation, oxygen supplementation or decreased physical activity level as compared to pre-pregnancy), cerebral impairment (seizures, unconsciousness, or cognitive/motor loss), renal failure (creatinine >1.5 mg/dL or increased >1.0 mg/dL above baseline, oliguria; <120 mL output in 4-hour intervals) and heart failure (impairment of cardiac function according to New York Heart Disease Classification [11]). The severity of the woman's condition at study admission was calculated by her mean arterial pressure (MAP); those with MAP <60 were in more severe condition. The formula for MAP is [2*diastolic blood pressure + systolic blood pressure]/3 [12]. Treatment variables included adherence to the clinical protocol of administering >1500 mL crystalloid fluids in the first hour after study admission, administration of blood transfusions, and administration of uterotonics for uterine atony. Outcomes of the study were mortality, severe end-organ dysfunction morbidity, measured blood loss, and emergency hysterectomy for uterine atony cases. Paper and pen data collection forms were completed by trained clinician/data collectors at the time of treatment or shortly after. Data supervisors in each country reviewed the data forms for completeness and accuracy. Data forms were sent to the University of California, San Francisco (UCSF), entered into a Microsoft Access database (Microsoft, Redmond, WA, USA), checked for errors and inconsistencies and analyzed. In Egypt, the paper forms were sent electronically to UCSF through a data fax system (Clinical DataFax Systems Inc., Ontario, Canada). Data Analysis: The analysis used combined data from the four largest Nigerian tertiary facilities (n = 452) and from two facilities in Egypt (n = 990); the total sample for analysis was 1442. The demographic characteristics, condition on study entry and treatment received for women in the two study phases were compared using two-sided t-tests of differences in the means of continuous variables (assuming unequal variances in the two study phase populations); the Wilcoxon rank sum test was used for non-normally distributed continuous variables (normality was tested using qnorm and sktest in Stata.), and chi-square tests of independence were used for dichotomous variables (with Fisher’s exact tests used where required). Relative risks (RR) with 95% confidence intervals were computed for the primary outcomes, mortality and severe maternal morbidity, and for the secondary outcome of emergency hysterectomy (for cases of primary or secondary diagnosis of uterine atony). From the RRs, we calculated the number needed to treat for benefit (NNTb) to prevent each of these outcomes, including an NNTb to prevent a case of either mortality or morbidity. An additional secondary outcome, the volume of measured blood loss in the drape (mL), was compared across study phases with the Wilcoxon rank sum test. To estimate the independent effect of the NASG intervention on mortality and severe maternal morbidity while controlling for other characteristics, we fitted a multiple logistic regression model for each of the two outcomes. The independent variables included in the two models, in addition to study phase, were selected on the basis of their significant associations with the outcomes in bivariate analyses. These were severity of shock (MAP <60); parity (0-4 vs. 5 or more live births); primary definitive diagnosis of uterine atony vs. another diagnosis; and whether the woman began bleeding outside the facility or not (for the morbidity model only, as this variable was not significantly associated with mortality in bivariate analysis). In addition, facility was included as a control variable in order to hold constant the effect (on the outcomes) of any unmeasured systematic differences in the characteristics of the six clinical populations or in the quality of care provided in the six settings. We anticipated violations of the independent and identically distributed (I.I.D.) assumption in the data because of clustering at the facility level, which would cause standard errors in the regression models to be biased; therefore, we used robust standard errors (using vce (robust) post estimation command for logistic regression in Stata) to address this problem. The confidence level for all tests was set to 95%. Data were analyzed using Stata/SE (version 10). Written informed consent was obtained for publication of the figure.