O.R. Eyelade1, O.A. Adesina2, I.F. Adewole2 and S.A. Adebowale3
- Department of Anaesthesia, College of Medicine, University of Ibadan, Ibadan, Nigeria.
- Dept. of Obstetrics and Gynaecology, College of Medicine, University of Ibadan, Ibadan, Nigeria.
- Dept. of Epidemiology and Medical Statistics, College of Medicine, University of Ibadan, Ibadan, Nigeria.
Background: Group specific blood is often cross-matched ready for all patients scheduled for caesarean section in anticipation of haemorrhage during the surgery. This study was conducted to determine the risk factors for blood transfusion during anaesthesia for caesarean section.
Methods: This was a prospective cross-sectional study. A total of 706 pregnant patients scheduled for emergency or elective Caesarean section at the University College Hospital, Ibadan, Nigeria between March and August 2011 were recruited. Participants were followed-up from the date of delivery till the end point of the study which could fall into either of the following conditions: satisfactory postoperative clinical status up to 48 hours post-delivery or death. Transfusion rate was determined and Chi-square test was used to determine if there exist an association between blood transfusion status and preoperative haematocrit level, years of experience of obstetrician, indication for Caesarean Section(CS), CS type (primary or repeat) and HIV status.
Results: Transfusion rate was 9.1 %; variables found to be significantly associated with blood transfusion were; preoperative haematocrit less than 26%, increasing parity, years of experience of resident obstetrician, indication for CS (bleeding or not bleeding) and estimated blood loss. Being HIV positive does not increase the need for blood transfusion.
Conclusion: Preoperative anaemia, increasing parity and severe blood loss at surgery significantly contribute to the requirement for blood transfusion in patients undergoing caesarean section.
Keywords: Blood transfusion, Caesarean delivery, Risk factors, Anaemia
Dr. Olayinka R. Eyelade
Dept. of Anaesthesia,
University College Hospital,
Operative delivery poses the risk of excessive blood loss and possible need for blood transfusion in the pregnant patient. Factors predisposing to increased risk for blood transfusion identified from previous studies include preoperative anaemia, previous Caesarean section and antepartum haemorrhage among others.1-3 However, other factors that may significantly affect blood loss during Caesarean section (CS) such as the level of expertise of the surgeon and the presence of co-morbidities which predispose to anaemia in pregnancy4 (such as Human Immunodeficiency Virus (HIV) infection) have not been previously studied in our institution. Anaemia in pregnancy is not uncommon in our setting, with prevalence of 25-30% being reported in Ibadan.5,6 Various studies2,3,7,8 have shown that severe antepartum haemorrhage from causes such as placenta abnormalities can lead to anaemia and are significantly associated with blood loss with the attendant risk of blood transfusion during operative delivery.
The large scale deployment of antiretroviral agents has led to improved survival of People Living with HIV and AIDs (PLWA). With increasing well-being, many PLWAs are getting pregnant and may require operative delivery on account of Preventing Mother-to-Child Transmission (PMTCT) of HIV at centers such as the University College Hospital, Ibadan which is a major training institution for obstetricians. The pregnant HIV positive parturient may be at increased risk for blood transfusion requirement due to various haematological abnormalities such as bone marrow depression, anaemia9 and haemosuppressive effects of antiretroviral agents such as zidovudine or antiviral agents like ganciclovir.10,11
Availability of blood and blood products for transfusion remains a major challenge in resource poor setting such as Nigeria. Factors that have been noted to contribute to delay in blood transfusion include constraints in blood banking and donation as well as cost (economic) and religious issues.12 This study was carried out to determine risk factors for blood transfusion in patients who had Caesarean delivery at our institution. In addition, we also compare blood transfusion rates in HIV negative patients with HIV positive patients. It is hoped that knowledge of blood transfusion predictors in this patient population will promote proper use of the few blood units available in low resource settings such as ours.
PATIENTS AND METHODS
This prospective cross-sectional study was carried out at the University College Hospital, Ibadan. Approval was obtained from the Institutional Ethics Committee. All women who had Caesarean Section [CS] were eligible for participation; however, a total of 706 pregnant women who had CS were recruited using non-probability sampling method. Written informed consent was obtained from participants. Data was collected over a six month period (March – August 2011). Participants were followed-up from the date of delivery till the end point of the study which was either satisfactory post-operative clinical status up to 48 hours post-delivery or unstable blood pressure (low or high blood pressure) or delayed recovery from anaesthesia requiring intensive care unit admission until discharge to the ward, or death.
The dependent variable was the patient’s blood transfusion status, that is, whether or not blood was transfused intra-operative or post-operative. This was categorized into two: Blood transfusion status (Received or Not received). Estimation of blood loss was by visual inspection of the number of soaked gauze pieces, abdominal packs and volume of blood in the suction bottle. The need for blood transfusion in an individual participant was determined by the attending anaesthetist (mostly senior registrars) based on the estimated blood loss and the clinical status of the participant. The attending anaesthetist also requested for blood from the blood bank. Haematologists were invited for specialized care of patients who developed features of Disseminated Intravascular Coagulopathy (DIC).
The independent variables included; preoperative haematocrit level (Packed Cell Volume), haematocrit level up to 26% or less than 26% was used to determine association between preoperative anaemia and the risk of blood transfusion in the analysis. Other independent variables included years of experience of the lead obstetrician, indication for Caesarean Section (CS), CS type (primary or repeat) and HIV status. With regards to the years of experience of the lead obstetrician, 4 years was identified as the dividing line because it is expected that by this time, residents should have received adequate training to acquire the necessary skills to perform Caesarean Section.