Radioisotope dilution technique for measurement of blood loss associated with lower segment caesarean section

One-compartmental biometric blood loss calculation after cesarean section

Blood loss during cesarean section was calculated based on post-operative decrement of hemoglobin (Hb) and hematocrit (Hct) level. The model used for pregnant women was previously validated for non-pregnant women who underwent gynecological surgery. 1,068 pregnant women who underwent cesarean section and 517 women who underwent gynecological surgery were included in the study. Regression lines between collected (x) and calculated (y) blood loss in pregnant women (y = 0.164 + 0.602x) and non-pregnant (y = 0.255 + 0.750x) women were statistically parallel. This study confirmed the applicability of one-compartmental model based on the drop in Hb levels for blood loss calculations for both gynecological surgery and cesarean section. Improved methods for calculating blood loss, V after cesarean section as V = [0.0115 × body weight (kg) × ln (preoperative Hb/postoperative Hb)] + [0.1905 × height³ (m) × ln (preoperative Hb/postoperative Hb)] + 0.3158 and after gynecological surgery V = [0.004 × body weight (kg) × ln (preoperative Hb/postoperative Hb)] + [0.4624 × height ³(m) × ln (preoperative Hb/postoperative Hb)] + 0.0472 were suggested.

Measurement of blood loss: review of the literature

It is important to recognize excessive blood loss during childbirth, which is a significant cause of morbidity and mortality. This article reviews methods to measure blood loss that could be used during childbirth. PubMed, CINAHL, and MEDLINE databases were searched using the phrases "blood loss" and "measurement." The bibliographies of publications were scanned for applicable references. A total of 46 publications are included in this review. The methods used to measure blood loss are categorized into visual estimation, direct measurement, gravimetric, photometry, and miscellaneous. Methods are described and compared. A combination of direct measurement and gravimetric methods are the most practical. Photometry is the most precise, but also the most expensive and complex to use. A variety of miscellaneous methods are presented, but none is a practical or reliable method. Visual estimation of blood loss is so inaccurate that its continued use in practice is questionable and it should not be used in research to evaluate treatment.

Trends in postpartum hemorrhage in high resource countries: a review and recommendations from the International Postpartum Hemorrhage Collaborative Group

BACKGROUND

Postpartum hemorrhage (PPH) is a major cause of maternal mortality and morbidity worldwide. Several recent publications have noted an increasing trend in incidence over time. The international PPH collaboration was convened to explore the observed trends and to set out actions to address the factors identified.

METHODS

We reviewed available data sources on the incidence of PPH over time in Australia, Belgium, Canada, France, the United Kingdom and the USA. Where information was available, the incidence of PPH was stratified by cause.

RESULTS

We observed an increasing trend in PPH, using heterogeneous definitions, in Australia, Canada, the UK and the USA. The observed increase in PPH in Australia, Canada and the USA was limited solely to immediate/atonic PPH. We noted increasing rates of severe adverse outcomes due to hemorrhage in Australia, Canada, the UK and the USA.

CONCLUSION

Key Recommendations 1. Future revisions of the International Classification of Diseases should include separate codes for atonic PPH and PPH immediately following childbirth that is due to other causes. Also, additional codes are required for placenta accreta/percreta/increta. 2. Definitions of PPH should be unified; further research is required to investigate how definitions are applied in practice to the coding of data. 3. Additional improvement in the collection of data concerning PPH is required, specifically including a measure of severity. 4. Further research is required to determine whether an increased rate of reported PPH is also observed in other countries, and to further investigate potential risk factors including increased duration of labor, obesity and changes in second and third stage management practice. 5. Training should be provided to all staff involved in maternity care concerning assessment of blood loss and the monitoring of women after childbirth. This is key to reducing the severity of PPH and preventing any adverse outcomes. 6. Clinicians should be more vigilant given the possibility that the frequency and severity of PPH has in fact increased. This applies particularly to small hospitals with relatively few deliveries where management protocols may not be defined adequately and drugs or equipment may not be on hand to deal with unexpected severe PPH.

Pregnancy in carriers of haemophilia

The aim of the study was to review the complications, management and outcome of pregnancy in carriers of haemophilia over a 10-year period following the introduction of a multidisciplinary management guideline. Comparison was made to a 10-year cohort prior to implementation of the guidelines. A retrospective review of case notes of carriers of haemophilia (41 haemophilia A, 12 haemophilia B) who had received obstetric care at the Royal Free Hospital between 1995 and 2005 was conducted. There were 90 pregnancies (65 live births, 13 miscarriages, 12 terminations). Prenatal testing was taken up in 97% (63/65) of pregnancies where the mother was known to be a carrier of haemophilia. The majority (71%; 46/65) chose only to have non-invasive fetal sex determination. Seventeen (26%) had invasive testing (13 primarily for haemophilia and four primarily for chromosomal abnormalities). Termination of pregnancy was opted for in 67% (6/9) of pregnancies affected with haemophilia. Pregnancy was accompanied by a marked rise in factor VIII levels compared to only a small rise in factor IX levels. Invasive intrapartum monitoring techniques and instrumental deliveries were avoided in all pregnancies known to be at risk of haemophilia. Regional block was performed in 25 pregnancies for labour/delivery with no complications. The caesarean section rate was 47%. The incidence of primary and secondary postpartum haemorrhage was 19% and 2%, respectively. There were two neonatal head bleeding complications associated with prolonged labour or instrumental delivery. Availability of management guideline and care provided in a multidisciplinary approach can help to minimize bleeding complications in carriers of haemophilia and their newborns.

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

OBJECTIVES

Following the results of the Confidential Enquiries into Maternal Deaths report, which claims two maternal deaths annually in the UK from postpartum haemorrhage, our aim was to assess the accuracy of 'visual estimation of blood loss' and produce suitable pictorial and written algorithms to aid in the recognition and management of massive obstetric haemorrhage.

DESIGN

Observational study to determine discrepancy between actual blood loss (ABL) and estimated blood loss (EBL).

SETTING

Teaching hospital.

POPULATION

Hundred and three obstetricians, anaesthetists, midwives, nurses and healthcare assistants.

METHODS

Clinical scenarios were reproduced in the form of 12 Objective Structured Clinical Examination (OSCE) style stations augmented with known volumes of whole blood. Individual staff estimated the blood loss visually and recorded their results. Digital photographs were used to produce a pictorial 'algorithm' suitable for use as a teaching tool in labour ward.

MAIN OUTCOME MEASURES

Areas of greatest discrepancy between EBL and ABL.

RESULTS

Significant underestimation of the ABL occurred in 5 of the 12 OSCE stations: 500-ml (50-cm diameter) floor spill, 1000-ml (75-cm diameter) floor spill, 1500-ml (100-cm diameter) floor spill, 350-ml capacity of soaked 45- x 45-cm large swab and the 2-l vaginal postpartum haemorrhage on bed/floor.

CONCLUSIONS

Accurate visual estimation of blood loss is known to facilitate timely resuscitation, minimising the risk of disseminated intravascular coagulation and reducing the severity of haemorrhagic shock. Participation in clinical reconstructions may encourage early diagnosis and prompt treatment of postpartum haemorrhage. Written and pictorial guidelines may help all staff working in labour wards.

How well does epidemiological evidence hold for the relationship between smoking and adverse obstetric outcomes in New South Wales?

This study examines whether the established epidemiological relationship between cigarette-smoking exposure in pregnancy and adverse obstetric outcomes are confirmed in Australian data from the NSW Midwives Data Collection (MDC). These data were analysed to compare the obstetric complications and pregnancy outcomes between smoking and nonsmoking women confined in 1994. Results showed that smoking mothers had higher rates of antepartum haemorrhage due to placental abruption and placenta praevia. They were also at higher risk of giving birth to low birth-weight babies and preterm delivery. Infants born to smoking mothers were 17% more likely to be admitted to hospital special care nurseries or neonatal intensive care units. Moreover, the risk of reported perinatal death among babies of smoking mothers was 20% higher than babies of nonsmoking mothers. However, smoking during pregnancy was found to confer a protective effect against the development of pregnancy-induced hypertension. These results were compared with existing evidence from the literature. Published research reports on the corresponding smoking effects were identified to assess the consistency of evidence and typical risk ratios. Findings from the literature search showed a near-perfect concordance with the associations in the NSW MDC data. The paper documents the likely complications which might be prevented if smoking in pregnancy were eliminated. There remains a real need for effective programmes to reduce smoking prevalence in pregnancy.