Postpartum Hemorrhage
Conditions
Keywords
Estimated Blood Loss, Obstetrics, postpartum hemorrhage
Brief summary
Post-partum hemorrhage (PPH) is defined as blood loss greater than 500 mL after vaginal delivery. Delayed diagnosis of PPH is a major cause of maternal morbidity and mortality. Obstetricians estimate blood loss at delivery by visual estimation of blood collected in the obstetric drapes. Blood is often mixed with urine and surgical sponges. The urine, blood, and sponges collect in a cone shaped plastic bag that is suspended from the perineum during delivery. Visual estimation of blood loss is insensitive in diagnosing PPH. In one study visual assessment of blood loss underestimated postpartum blood loss by 33% to 50% compared to an objective measurement of blood loss using photospectrometry. Other studies have shown that the magnitude of underestimation increases as the amount of blood loss is increased. A limitation of previous studies is that there is no gold standard for blood loss determination in the third stage of labor. Care providers (obstetricians, anesthesiologists, and labor & delivery nurses) need to be able to accurately estimate blood loss in order to better care for mothers and prevent morbidity and mortality. It is unknown whether provider type or experience (obstetric and anesthesiology resident, fellow, attending physicians, and nurses) influences the accuracy of blood loss estimation, or whether blood loss estimation can be improved by providing graduated markings on the vaginal delivery drape.
Detailed description
Packed red blood cells discarded by the blood bank will be mixed with normal saline to simulate whole blood with a hematocrit of 33%. A total of eight isolated study stations will be set up (study participants will only be able to visualize the vaginal delivery drape for one station at a time). The simulated blood will be mixed with urine and sponges and be placed in suspended blood collection drapes which are used during vaginal deliveries at Northwestern Memorial Hospital. Two types of drapes will be used: drapes without calibrated markings and drapes with calibrated markings. Calibrated volume markings will begin at 500 mL at 500 mL intervals to 2500 mL. Study participants will be randomized to one of two groups. Randomization will occur in blocks depending on provider type. Group 1 will view the unmarked vaginal collection drapes first and Group 2 will view the collection drapes with the calibrated markings first. Both groups will analyze the initial four study stations in random order. At the completion of the four study stations, the group which evaluated the drapes without markings will cross over to view the stations with calibrated markings and the group that views uncalibrated drapes will then view the calibrated drapes. Each study participant will view a station and write his/her estimation of blood loss on a data card. Study participants will NOT be allowed to change answers once they have been recorded. Demographic data on study participants will include provider type, level of training/years of practice, and gender.
Interventions
PROCEDUREblood loss estimation
Participants were randomized in blocks, by provider type to view either the four calibrated stations or the four non-calibrated stations. The order of the volumes within each set of stations was randomized. Participants received a data card for each station on which they wrote the volume estimated. After each station, the data card was collected. Alterations to the estimations were not allowed once the answers were recorded. Subjects were then crossed over to the other group and asked to estimate the blood volumes in the non-calibrated drapes if they had first viewed the calibrated drape or the calibrated drape if they had viewed the non-calibrated drape. The order of viewing the four volumes was again randomized. The volumes were the same at the corresponding station for the calibrated and non-calibrated stations so the impact of the calibration markings on accuracy could be determined.
Sponsors
Northwestern University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Any anesthesia or obstetric attending or resident may participate provided that they have rotated through obstetrics/obstetric anesthesia.
Exclusion criteria
* Any provider that does not complete all of the stations will be excluded from analysis. Any participant who chooses to withdraw from the study will also be excluded from the analysis.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Difference in Actual Blood Volume and Estimated Blood Volume in Milliliters. | 1 hour | Two types of drapes were used: drapes with and without volume calibrations. Calibrated drapes had volume markings beginning at 500ml with 500ml increments to a total of 2500ml. The participants were asked to estimate the volume contained in the bag and the difference in milliliters between the estimate and actual volume was calculated. |
Secondary
| Measure | Time frame |
|---|---|
| Number and Type of Care Providers Assigned to Study Arms. | 1 hour |
| Level of Training | 1 hour |
| Number of Years of Clinical Experience Providing Patient Care Requiring Blood Loss Estimation. | 1 hour |
Countries
United States
Participant flow
Recruitment details
The study was conducted on two separate dates at Prentice Women's Hospital. Eight stations were set up in 8-12 hour periods in an empty labor and delivery room. Participants were randomized in blocks by provider type. The order of the volumes was randomized. Subjects were not informed that the volumes in the two groups were the same.
Participants by arm
| Arm | Count |
|---|---|
| Calibrated Vaginal Delivery Drapes Viewed First Calibrated drapes had volume markings beginning at 500ml with 500ml increments to a total of 2500ml. Subjects were randomized to either view calibrated or uncalibrated (standard of care) drapes and asking to estimated volume of blood loss. Subjects were then crossed over and experiment repeated. | 53 |
| Noncalibrated Drapes Viewed First No distinguishable volume markings on drape (standard of care). Subjects were randomized to either view calibrated or uncalibrated (standard of care) drapes and asking to estimated volume of blood loss. Subjects were then crossed over and experiment repeated. | 53 |
| Total | 106 |
Baseline characteristics
| Characteristic | Calibrated Vaginal Delivery Drapes Viewed First | Noncalibrated Drapes Viewed First | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 53 Participants | 53 Participants | 106 Participants |
| Region of Enrollment United States | 53 participants | 53 participants | 106 participants |
| Sex: Female, Male Female | 34 Participants | 32 Participants | 66 Participants |
| Sex: Female, Male Male | 19 Participants | 21 Participants | 40 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 53 | 0 / 53 |
| serious Total, serious adverse events | 0 / 53 | 0 / 53 |
Outcome results
Primary
Difference in Actual Blood Volume and Estimated Blood Volume in Milliliters.
Two types of drapes were used: drapes with and without volume calibrations. Calibrated drapes had volume markings beginning at 500ml with 500ml increments to a total of 2500ml. The participants were asked to estimate the volume contained in the bag and the difference in milliliters between the estimate and actual volume was calculated.
Time frame: 1 hour
Population: per protocal
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Calibrated Vaginal Delivery Drapes Viewed First | Difference in Actual Blood Volume and Estimated Blood Volume in Milliliters. | 300 ml | -20.8 milliliters |
| Calibrated Vaginal Delivery Drapes Viewed First | Difference in Actual Blood Volume and Estimated Blood Volume in Milliliters. | 500 ml | -53.5 milliliters |
| Calibrated Vaginal Delivery Drapes Viewed First | Difference in Actual Blood Volume and Estimated Blood Volume in Milliliters. | 1000 ml | -32.8 milliliters |
| Calibrated Vaginal Delivery Drapes Viewed First | Difference in Actual Blood Volume and Estimated Blood Volume in Milliliters. | 2000 ml | -178 milliliters |
| Noncalibrated Drapes Viewed First | Difference in Actual Blood Volume and Estimated Blood Volume in Milliliters. | 2000 ml | -829.8 milliliters |
| Noncalibrated Drapes Viewed First | Difference in Actual Blood Volume and Estimated Blood Volume in Milliliters. | 300 ml | -41.7 milliliters |
| Noncalibrated Drapes Viewed First | Difference in Actual Blood Volume and Estimated Blood Volume in Milliliters. | 1000 ml | -145.3 milliliters |
| Noncalibrated Drapes Viewed First | Difference in Actual Blood Volume and Estimated Blood Volume in Milliliters. | 500 ml | -96.0 milliliters |
Comparison: Repeated measures ANOVA comparing all levels of blood estimation (P=0.0002). Post-hoc comparisons using Bonferroni corrects t-tests.p-value: <0.05ANOVA
Secondary
Level of Training
Time frame: 1 hour
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Calibrated Vaginal Delivery Drapes Viewed First | Level of Training | Attending physician | 19 participants |
| Calibrated Vaginal Delivery Drapes Viewed First | Level of Training | Resident physician | 22 participants |
| Calibrated Vaginal Delivery Drapes Viewed First | Level of Training | Nurse | 12 participants |
| Noncalibrated Drapes Viewed First | Level of Training | Attending physician | 22 participants |
| Noncalibrated Drapes Viewed First | Level of Training | Resident physician | 22 participants |
| Noncalibrated Drapes Viewed First | Level of Training | Nurse | 9 participants |
p-value: 0.72Chi-squared, Corrected
Secondary
Number and Type of Care Providers Assigned to Study Arms.
Time frame: 1 hour
Population: per protocol
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Calibrated Vaginal Delivery Drapes Viewed First | Number and Type of Care Providers Assigned to Study Arms. | Anesthesia | 21 participants |
| Calibrated Vaginal Delivery Drapes Viewed First | Number and Type of Care Providers Assigned to Study Arms. | Obstetrics | 20 participants |
| Calibrated Vaginal Delivery Drapes Viewed First | Number and Type of Care Providers Assigned to Study Arms. | Nursing | 12 participants |
| Noncalibrated Drapes Viewed First | Number and Type of Care Providers Assigned to Study Arms. | Anesthesia | 22 participants |
| Noncalibrated Drapes Viewed First | Number and Type of Care Providers Assigned to Study Arms. | Obstetrics | 22 participants |
| Noncalibrated Drapes Viewed First | Number and Type of Care Providers Assigned to Study Arms. | Nursing | 9 participants |
p-value: 0.76Chi-squared, Corrected
Secondary
Number of Years of Clinical Experience Providing Patient Care Requiring Blood Loss Estimation.
Time frame: 1 hour
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Calibrated Vaginal Delivery Drapes Viewed First | Number of Years of Clinical Experience Providing Patient Care Requiring Blood Loss Estimation. | < 5 years | 30 participants |
| Calibrated Vaginal Delivery Drapes Viewed First | Number of Years of Clinical Experience Providing Patient Care Requiring Blood Loss Estimation. | 5-10 years | 11 participants |
| Calibrated Vaginal Delivery Drapes Viewed First | Number of Years of Clinical Experience Providing Patient Care Requiring Blood Loss Estimation. | > 10 years | 12 participants |
| Noncalibrated Drapes Viewed First | Number of Years of Clinical Experience Providing Patient Care Requiring Blood Loss Estimation. | < 5 years | 29 participants |
| Noncalibrated Drapes Viewed First | Number of Years of Clinical Experience Providing Patient Care Requiring Blood Loss Estimation. | 5-10 years | 13 participants |
| Noncalibrated Drapes Viewed First | Number of Years of Clinical Experience Providing Patient Care Requiring Blood Loss Estimation. | > 10 years | 11 participants |
p-value: 0.89Chi-squared, Corrected