Pilot studies of the NASG

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Based on the successes of the case series in Pakistan, the authors and their in-country colleagues are conducting NASG pilot studies in comprehensive emergency obstetric care facilities in Nigeria (Dr Dosu Ojengbede, University of Ibadan), teaching facilities in Egypt (John Snow International), and in primary and secondary health facilities in Mexico (Population Council and IMSS-Opportunidades). These studies compare use of a standardized protocol of shock and hemorrhage care in the pre-intervention period with the same standardized protocol plus the NASG in the postintervention phase. The primary outcome was volume of measured blood loss after initiation of treatment with or without the NASG. To obtain a relatively objective measure of blood loss, maternal bleeding after admission to the study is measured using a specially designed, closed-end, calibrated plastic blood collection drape. Prior studies of this drape indicate that it is more accurate than visual assessment in measuring postpartum blood loss31. Secondary outcomes include severe acute maternal morbidities (SAMMs: acute respiratory distress syndrome, cardiac deficiency, central nervous system damage, and renal failure) and need for emergency hysterectomy. The standard protocol included: active management of third-stage labor, immediate use of uterotonics for suspected postpartum uterine atony, training in limited intravenous crystalloid fluid replacement32,33, and, in the post-intervention, prompt application of the NASG.

Inclusion criteria were obstetric hemorrhage with shock (minimum requirements: estimated blood loss > 750 ml, systolic blood pressure <100 mmHg and/or pulse > 100). There were a variety of obstetric hemorrhage etiologies, including postpartum hemorrhage due to atony or lacerations, ectopic pregnancies, ruptured uterus, complications of abortion, and a variety of placental pathologies. Overall, postpartum uterine atony and/or retained placenta or placental fragments accounted for 44% of all participants. Pre-intervention data were collected from May to September 2004. Postintervention data collection has been completed in Egypt and is underway in Nigeria and Mexico.

NASG pilot study in Egypt

The study sites in Egypt comprised highvolume referral CEOC teaching facilities (El Galaa, Alexandria, Assiut, and Al Minya). All are staffed by senior obstetricians and obstetric residents with immediate access to banked donor blood and surgery. Pre-intervention data, including measured blood loss, were collected for 3 months, after which all providers were trained in the use of the NASG. The only change to the pre-intervention clinical management was the use of the NASG. Postintervention data were collected for another 3 months.

The primary outcome was mean measured amount of blood lost after a woman entered the study. A sample size of 150 pre-intervention obstetric hemorrhage patients (no-NASGs) and 150 post-intervention obstetric hemorrhage patients (NASGs) was needed to detect a 50% difference in blood loss between the two groups with power (P) of 80% and a significance level (a) of 5%. The final study sample comprised 156 no-NASG and 204 NASG patients with obstetric hemorrhage who met the entry criteria. Diagnoses of obstetric hemorrhage covered a range of primary diagnoses with no statistically significant differences between no-NASGs and NASG patients. The three most common diagnoses were uterine atony, genital lacerations, and complications of abortion. The NASG

women had a statistically significant greater loss of blood on study entry and more severe signs of shock than did the no-NASG group. Estimated blood loss at entry to the study was 1000 ml for NASG cases and 750 ml for no-NASGs (p < 0.001), mean systolic blood pressure for NASG cases was 88.3 mmHg vs. 97.2 mmHg for no-NASGs (p < 0.001), and mean diastolic blood pressure was 56.7 mmHg for NASGs vs. 60.8 mmHg for no-NASGs (p = 0.005). A probable reason for the NASG group's worse condition on study entry was that the clinical researchers waited until women were in deeper shock before putting on the garment, a new technology that they were not accustomed to applying.

As shown in Table 1, NASG patients had 46% less mean measured blood loss (50% less median measured blood loss) than did those patients not treated with the NASG (p < 0.001). NASG and no-NASG patients had similar blood loss during surgery: NASG patients lost only 32 ml more (p = 0.748), and NASG patients had a lower amount of estimated 'other' blood loss (spilled on floor, on gauze or towels) compared to no-NASG cases (p = 0.209). Patients treated with the NASG had a statistically significant lower amount of post-study entry blood loss (drape + intraoperative + 'other') compared to no-NASGs (p < 0.001). The NASG group received 193.3 ml more blood than those not receiving the NASG (p = 0.034), and the NASG group also received 225.6 ml more of intravenous fluids (p = 0.06). There was a non-statistically significant 84% lower incidence of severe acute maternal morbidities (SAMMs) and mortalities, which were combined as 'extreme adverse outcomes'. One patient (0.5%) had an extreme adverse outcome among the NASG patients (renal failure), whereas five patients (3.2%) died or suffered SAMMs among the no-NASG patients (odds ratio (OR) 0.15, 95% confidence interval (CI) 0.02-1.31)34.

A greater percentage of patients in the NASG group had surgeries compared to no-NASG patients (49.0% vs. 37.8%, p < 0.03), perhaps due to their worse condition on study entry. The most common surgeries were Cesarean section and salpingectomy. Both groups spent

Table 1 Results from NASG Pilot study in Egypt

No-NASG (n = 156) Mean ± SD

NASG (n = 204) Mean ± SD

p Value

Mean blood loss measured with drape (ml)

561.6 ± 447.4

303.5 ± 219.5

< 0.001a

(median 500)

(median 250)

Mean intraoperative blood loss (ml)c

394.1 ± 537.5

426.0 ± 641.2

0.748b

Estimated 'other' blood loss (ml)c

196.3 ± 333

140.2 ± 221.3

0.209 b

Blood loss post-entry to study

902.7 ± 696.5

591.3 ± 532.0

< 0.001a

(drape + intraoperative + other) (ml)

(median 700)

(median 450)

Volume blood transfusion (ml)d

963.2 ± 668.4

1156.5 ± 707.8

0.034b

Volume intravenous fluids (ml)

2035.5 ± 1190.6

2261.1 ± 1033.3

0.057b

Extreme adverse outcomes

5 women (3.2%)

1 woman (0.5%)

OR 0.15, 95%

Selected variables: NASG

aMann-Whitney U test used for comparison of groups with unequal variances; from Student's T test; for the 159 women who had operations, 59 in the no-NASG group and 100 in the NASG group; dfor the 248 women who had blood transfusions, 95 in the no-NASG group and 153 in the NASG group

Selected variables: NASG

aMann-Whitney U test used for comparison of groups with unequal variances; from Student's T test; for the 159 women who had operations, 59 in the no-NASG group and 100 in the NASG group; dfor the 248 women who had blood transfusions, 95 in the no-NASG group and 153 in the NASG group almost equal time in the hospital following admission, NASG patients a mean of 2.0 ± 1.5 days, and the no-NASGs a mean of 1.9 ± 1.6 days (p = 0.50). Both groups received comparable dose of oxytocin; for those with uterine atony, the mean total was 30.7 units for no-NASG and 32.0 for NASG patients.

A sub-analysis of women who entered the study with severe hemorrhage (> 1500 ml) revealed no difference in frequency by study group, no-NASGs 26.9%, NASG 31.4%, p = 0.36. However, the mean volume of blood lost in the drape for the NASG group was 66% less than for the no-NASGs (278.1 ± 221.5 ml NASG vs. 818.1 ± 641.3 ml no-NASG, p < 0.001). This was a greater mean blood loss difference by study group than among all patients (with and without severe hemorrhage at study entry). A non-statistically significant decrease was found for extreme adverse outcomes; among those who did not receive the NASG, such outcomes occurred in four patients (9.5%) and in only one NASG patient (4.6%) (OR 0.5, 95% CI 0.1-1.9).

The results among this sample of women in university teaching hospitals appear very promising. While the women with the NASG had lost more blood and had greater signs of shock, the primary outcome of measured mean blood loss was statistically significantly less. The non-statistically significant difference in extreme adverse outcomes is promising, but will require a larger sample over a longer period of time in order to demonstrate if there is a true difference in this most important outcome.

NASG pilot studies in Nigeria and Mexico

Pilot studies are currently underway at four urban acute obstetric hospitals in Nigeria and in rural primary health-care facilities (Unidades Medicales Rurales or UMRs) with long transport times to rural CEOC facilities in Mexico. The design and methodology of these studies are similar to those in the Egypt study. One difference is that, in Mexico, pre-weighed adult diapers are used to collect blood during long transports between the UMRs and the CEOC facilities where women are brought for definitive treatment. (The blood collection drapes used in the CEOC tend to slip off during the often multiple vehicle changes involved in transport from the UMRs.) The used diapers are weighed at the CEOC facilities and blood volume is calculated from the weight of the diaper; at the CEOC facilities, the diapers are then replaced by the closed-end plastic blood collection drape. In Mexico, the number of no-NASG cases was ten and the number of NASG cases 27.

The following case history illustrates the application of the NASG in a rural Mexican community. A 25-year-old woman, gravida 2 para 1, delivered at home attended by a traditional birth attendant (TBA) who had been sensitized to the need for transport in the NASG by community outreach. When the woman began to hemorrhage from a retained placenta, the TBA arranged transport to a study UMR. The trip took over 2 h; on arrival at the UMR, it was estimated that the patient had lost more than 2000 ml blood and had a pulse of 160. The NASG was applied and the woman transported by ambulance another 2 h to a CEOC facility. Blood loss during the trip was measured at 300 ml. At the hospital, intravenous fluids were started, a manual removal of the retained placenta was performed, and two units of blood were transfused. The patient was discharged with a hemoglobin level of 8.

In contrast to the community setting in Mexico, the Nigerian study is set in urban CEOC hospitals. Before introducing the NASG protocol, data were collected for 3 months, as in the other pilots. While data are still being collected in this study, an interim analysis includes 27 no-NASG patients and 63 with NASG. The most common diagnoses are antepartum hemorrhage and postpartum hemorrhage, i.e. 12 women (44%) in the non-NASG group versus 39 (65%) in the NASG group. The estimated blood losses on study entry were similar for both groups (1258 ml vs. 1487 ml), but the NASG women had more severe symptoms of shock, with a mean blood pressure of 53/23 mmHg compared to 91/55 mmHg. The percentage with Class 3 or Class 4 shock in the NASG group was also greater, 85% vs. 22%. According to the protocol, measurements of blood loss were to be made using the same closed-end blood collection drapes used in the Egypt study. However, in some cases, this could not be accomplished and visual estimates were made of blood loss. In all cases, the amounts of blood lost and replaced were reconciled with the admission and subsequent hematocrit values. The difference in measured plus estimated blood loss after study entry was more than a liter greater in the no-NASG group, 1385 ml vs. 257 ml.

An interim analysis from the Nigeria study concerns the recovery of 33 women with severe postpartum hemorrhage35. This subset of women met three of the four American College of Surgeons' Class III or IV shock criteria: > 1500 ml blood loss, packed cell volume

< 80/50 mmHg, and altered mental status. During resuscitation, the vital signs were recorded every 15 min. Although not always accomplished, the protocol advised giving 1500 ml saline rapidly, followed by additional saline to achieve minimum blood pressure of 80/50 mmHg, corresponding to a mean arterial pressure of 60 mmHg.

Thirty-two women survived without morbidity; one woman expired. Among the 32 surviving women, the estimated mean blood loss upon study entry was 1471 ml and mean packed cell volume 18.9%. Mean measured and estimated blood loss with the NASG in place was 220 ml. Mean volume of blood transfused was 1442 ml and the discharge packed cell volume 23.8%. After placing the NASG, 28 of the 32 women had improvement in their vital signs by the next 15-min recording. The resuscitation interval (the time from placement of the NASG until achieving a mean arterial pressure > 60 mmHg) was 52 min. The patients with more rapid intravenous saline infusion responded more rapidly; those receiving an infusion at > 1000 ml/min recovered in 24 min while those receiving

Preliminary analysis: Nigeria and Egypt severe hemorrhage

A recent analysis was conducted combining the Egypt data34 and data from six tertiary-care hospitals in Nigeria on all women (n = 263) with severe hemorrhage (estimated blood loss on admission > 1000 ml, pulse > 120). There were 104 in the pre-intervention, standard-care group, and 159 treated with standard care and the NASG. There were no differences in the pre-intervention and NASG groups by country or age. There were a variety of diagnoses; the leading cause of hemorrhage was uterine atony, approximately 33%. The patients' conditions on study entry were statistically similar in the two groups. The difference in median blood loss in the drape after treatment was statistically significantly different; those in the NASG group lost 64% less, 250 ml vs. 700 ml (median difference 490 ml, 95% CI: 350-600 ml). Neither mortality alone, n = 7 (6.7%) for pre-intervention vs. 3 (1.9%) for the NASG groups, nor severe morbidity, n = 5 (5.3%) vs. 2 (1.3%), were statistically significantly different. However, a combined severe adverse outcome variable, a combination of mortality and SAMMs, was statistically significantly different, with those in the NASG group less likely to suffer a severe adverse outcome, RR = 0.28, 95% CI 0.10-0.7736.

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