Denny, L.

James, M.

Megevand, E.

Nevin, J.

van Wyk, E.

English

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ORIGINAL ARTICLESBLOOD ORDERING PRACTICES INTHE MANAGEMENT OF ECTOPICPREGNANCY AT GROOTE SCHUURHOSPITALJ Nevin, E van Wyk, L Denny, E Megevand, M JamesObjective. To investigate transfusion practices in themanagement of patients with ectopic pregnancy and to usethis information to establish guidelines.Design. A prospective, longitudinal study.Setting. Groote Schuur Hospital, Cape Town.Subjects. All patients treated for ectopic pregnancy.Methods. To prevent the Hawthome effect, resident medicalstaff were Rot informed of the true nature of the study. Theappropriateness of their transfusion practices was assessedby measuring postoperative haematocrits, and the influenceof shock, transfusion volumes and admission haemoglobinconcentrations was investigated.Results. One hundred and five patients were analysed. Sevenand 15 patients were over- and undertransfused respectively,giving an overall transfusion error rate of 21%. Whentransfused volumes were increased, rates of transfusion errorincreased insignificantly. No patients were administeredsingle-unit transfusions. Shock (P < 0.004) and an admissionhaemoglobin concentration < 10g/dl (P < 0.001) weresignificantly associated with transfusion errors.Conclusions. Transfusion errors are common andundertransfusions are more frequent than overtransfusions.After transfusing a patient with three units of blood thehaematocrit should be checked before additional units aretransfused. Shocked patients and patients with admissionhaemoglobin concentrations < 10 g/dl deserve specialattention. Single-unit transfusions can be considered.Financial resources for blood transfusions are not beingsquandered.5 Afr Med J1999; 89: 1003-1005.Department of Obstetrics and Gynaecology, University of Cape Town.J Nevin, MB BCh, MMed (O&G), MRCOG, FCOG (SA)E van Wyk, MB ChB, FCOG (SA)L Denny, MB ChB, MMed (O&G), FCOG (SA)E Megevand, MDDepartment of Anaesthesia, University of Cape TownM James, MB ChB, PhD, FFARCSWhile the risk of haemolytic reactions and infectiouscomplications have put the transfusion of blood and itsproducts under the spotlight, financial implications are alsoimportant and at Groote Schuur Hospital (GSH) the pressure onclinicians to justify expenditure has increased dramatically. As aconsequence the Department of Obstetrics and Gynaecologyinitiated formal assessment of transfusion practices.Since emergency admission for the management of ectopicpregnancy is common and carries the possibility of transfusion,patients with this pathology were considered a meaningfulgroup on which to commence this audit process. In attemptingto measure the appropriateness of blood transfusion practices,we hoped to establish the extent and cause(s) of the problem, todesign guidelines for better practice and to calculate transfusionbudgets for this particular complication of pregnancy.PATIENTS AND METHODSThe study design was prospective and longitudinal. Using thestatistical package Statgraphics (Version 6), a binomialdistribution and an assumption that 30% of patients wereincorrectly transfused with a beta error probability of 10%, itwas calculated that 24 transfused patients would be needed toshow a statistically significant incidence of transfusion error.Since 34 of 117 patients with ectopic pregnancies had beentransfused during a 22-week preliminary observation period, astudy size of at least 100 patients was chosen.Patients with newly diagnosed ectopic pregnancy wereprospectively and consecutively recruited. In order to limit theHawthome effect,' the true nature of the study was concealedfrom the attendant medical staff.Data on transfusions, the presence / absence of shock, andadmission haemoglobins (determined using capillary blood andthe Buffalo Medical Specialties (BMS) portablehaemoglobinometer) were collected from patient and bloodbank records.Postoperative haematocrits (Hcts) were measured on thesecond postoperative day using a Technicon HI automatedblood counter.Using a post-transfusion haematocrit range of 0.24 - 0.32 as amarker of appropriate transfusion, transfusion errors werediagnosed if the postoperative Hct was < 0.24(undertransfusion), or if the postoperative, post-transfusion Hctwas> 0.32 (overtransfusion).Results were stored and analysed on Microsoft Excel Version 5.Standard statistical techniques were used to analyse therelationships between rates of transfusion error and transfusionvolume, shock and admission haemoglobin. Calculationsincluded the chi-square test (with Yates' correction wherenecessary) and Fisher's exact test. Statistical significance wasaccepted at P < 0.05.Consent was obtained from each patient and approval for thestudy was granted by the Ethics and Research Committee of theUniversity of Cape Town.Table D. Relationship between shock and transfusion errorTable I. umber of units transfused v. rates of transfusion enorumber of units transfusedWhat the current study did highlight wa that errors appliednot only to the excessive administration of blood. Mistakes werealso made by withholding transfu ions. The latter point is oftenignored and deserves more attention.' It should not be forgottenthat inadequate transfusions can result in silent myocardialischaemia'DISCUSSIOBy using th definition of well-tolerated normovola mianaemia (Hb 7 -10 g/d!) t out in the American CoUeg ofPhy icians guidelin for transfu ion,> and allowing for amargin of ety, a ha matocrit between 0.24 and 0.32 wch n marker of appropriate transfusion practice. Th'methodology is predictably open to dispute since empirical,automatic transfusion threshol are probably archaic. It isbetter to base blood adm.in.istration on circuJatory compet~ceand symptomatology in a normovolaemic low-risk patient.However, ince the tudyof ymptom-driven phy 'cianpractic might be biased by th Hawthome effect, acompromise was ntial. While the tool chosen in this tudyto identify transfu ion errors may have been imperfect, it hasbeen used previou I and the inconsistencies exposed in themanagement of ectopic pregnancies were probably genuine andimprovements attainable. As transfusion medicine is currentlyin its infancy: we had to work with the tools at our disposal.Thi tudy howed that transfu ion practices wereinappropriate and could have been improved in 21% of womenadmitted to GSH for the management of ectopic pregnancy.However, comparisons with other audits were reassuring.Despite the emergency nature of ectopic pregnancy, the rate ofovertransfusion (26%) wa less than that reported duringelective urgery. Tartler et al.' tudied patients undergoingelective colorectal resections and labelled 69% of transfusions asexcessive. Guavanetti et al.' looked at a much larger populationof transfused patients undergoing a variety of electiveprocedures and found that 33% had Hcts > 36%. A previousreport from Groote Schuur H pital' looked at elective surgeryand identified 27% of postoperative transfu ions a beingexcessive.This tudy found that transfusion of more than three units ofblood was often exc ive. We conduded that a repeat Hb/Hctestimation is necessary before additional blood is administeredto a patient who has received a three-unit transfusion.All patients in the present series who received bloodtransfusions received more than one unit of blood. Till findinguggests an avoidance of ingle-unit transfusions. Despite anearlier warning about the effect of !hi practice on rates ofovertransfusion in thi country,' this traditional approachcontinues to be advocated in South Africa.' It is certainly atvariance \vith orth American practice. In a 19 publicationTartler et aI.' attributed increased blood usage to a 1970 editorialthat resulted in 'the unfortunate practice of orderin bloodtransfu ions in pairs of units'. The 1992 Ame.rican College ofPhy icians Clinical Guidelin state that 'one unit ma beufficient'. Finally, a recently published randomised, prospective549194724 - 6Shock present21113157 - 22Shock absent0 2 3 >3Overtransfu ions ( ) 1 1Undertransfusions ( 13 2 2 3Transfu ion errors ( ) 13 3 3 3Patients ( ) 7 12 9 6Transfusion error rate (%) 17 25 33 50Overtransfu .ons ( )Undertransfusions ( )Transfu 'on erro ()Patien ()Transfusion error rate (%)95%0(%)RESULTSOne hundred and ten patien with newly diagnosed ectopicpregnancy were consecutively recruited for thi study from1 Augu t to December 1996. Five patien were excludedpost perative H were unavailable for 4 and 1 had anautotransfusion; consequ ntly th tudy group c isted of105 pati n .Of th ,27 (26%) were tran fused a total of 71 uni of blood.in ty-eight uni of blood were er -matched for a cross-match transfusion ratio of 1.3.Of 27 transfused patien ,7 were ov r- and 2und rtransfused, giving a tra fu ion error rate of 33.3% with a95% confid nce interval ( I) (16%, 51%). Of the 7 patients whowere not transfused, 13 (17%) h uld, by definition, have beentransfused. The number of over- and undertransfusions wastherefore 7 and 15 r pectively for an overall transfusion errorrate of 21 % with 0 (13%,29%). Table I how that the rates oftransfu ion errors did not depend on the volume of bloodtran fused (P = 0.1 ).The transfusion error rate \ as greater if hock was present(47% hocked patient) compared with 15% if hock wa absent(P = 0.004, Fisher' exact test). Rates of over- andundertransfu ion in hocked patients did not differ. In theab nce of hock, undertransfu ion wa significantly morecommon than overtransfu ion (P = 0.00 ,Fisher' exact test).These results are ummarised in Table II. One patient wasthought to have developed pulmonary oedema a aconsequence of undertransfusion during resuscitation.Transfu ion errors occurred more often if adrrus ionhaemoglobins (Hb ) were < 10 (chi-square with Yates'correction, P < 0.0001). Of 39 patients with adrni ion Hb> 11 gldl, none were tran fu d and only 1 patient had apo toperative Hct < 0.24.September 1999, 01. 9, o. SAMJ11trial comparing 'restrictive' and 'liberal' transfusion practices inCanadian critical care units'O used transfusions on a unit-by-unitbasis, with Hb checks after each unit. It is therefore clear thatsingle-unit transfusions are acceptable to many practitioners,and in the absence of any evidence to the contrary these shouldbe utilised in the management of ectopic pregnancies.All shocked patients who were not given transfusions wereleft very anaemic. It was concluded that all shocked patientswith ectopic pregnancies deserved transfusions. However thepresence of shock is a strong confounding variable because itrenders the judgement of an appropriate transfusion volumemuch more difficult. One can easily give too much.Admission Hb had limitations as a guide to transfusionpractice. Although an admission Hb > 11 g/ dl appeared to be acontraindication to blood transfusion and patients withadmission Hbs < 10 g/ dI were at greatest risk of transfusionerror and undertransfusion in particular, to offer firm guidelineswas impossible. Since the method of Hb estimation used in thisstudy has been validated using venous rather than capillarysamples/ further studies are justified.From a financial point of view, the cost of overtransfusionswas offset by the inadvertent savings that accrued as a result ofthe transfusions that were inappropriately withheld. The resultswere used to estimate what a South African gynaecologicalservice requires for the transfusion of patients with ectopicpregnancies. Although 20% of patients were managedincorrectly, the overall study group justified at least 77 units ofblood, and in the light of a low cross-match transfusion ratio(1.3), it appears from this study that the budget for each SouthAfrican patient with an ectopic pregnancy will need to includethe cost of one unit of blood.The authors thank Dr Jocelyne Kane-Berman for authorisingfree access to the Groote Schuur Hospital haematologylaboratory, Dr Arthur Bird for giving advice on the manuscript,and the junior doctors in the Department of Obstetrics andGynaecology for collecting blood specimens. The authors alsothank the 110 women who were recruited for this study.References1. Abramson IH. Survey Methods in Community Medicine. London: Churchill livingstone, 1979:49-57.2. linegar AG, Knottenbelt JD, Wormald PI. Accuracy of a postable haemoglobinometer inclinical practice. 5 Aft Med I 1991; 79: 547-548.3. American College of Physicians Oinical Guideline. Practice strategies for elective red bloodcell transfusion. Ann Intern Med 1992; 116: 403406.4. Tartter Pr. Baron DM,. Quintero S. Perioperative transfusions associated. with colorecta1surgery: clinical judgement versus the haematocril Wurld / Surg 1986; 10: 51~521.5. Guavanetti A..y' PaITavacini A. Baroni L, et al. Quality assessment of transfusion practice inelective surgery. Transfusion 1988;~: 166-169.6. Napier J.-\.F. Towards more rational use of red cells. Lznaf 1994; 343: 1280.7. Rund RL, Bird AA James M)M. Blood usage in elective surgery - a ~monthly audit ateroote Schuur Hospital, Cape TO"'"IL 5 Aft Med I 1992; 81: 415-418.8. lenfant C. Transfusion practice should be audited for both undertransfusion andovertransfusion. Transfusion 1992; 32: 87".>-874-9. Cltigumadzi P- Moodley J. The utilisation of blood and blood products in obstetric practice atKing Edward vm HospitaJ, Dmban. 0 & e Forum 1997; 7: 12-20.10. Hebert PC, Wells e, 8lajchman M.-'\., Marshal I, Martin C, Pagliarello G, Tweedale M.Schweitzer I, Yetisir E and the Transfusion Requirements in Critical Care Investigators for theCanadian Critical Care Trials Group. A multicenter. randomized controlled clinical trial oftransfusion requirements in critical care. N Engl JMed 1999; 340: 409-417.PROLACTIN LEVELS IN SOUTHAFRICAN WOMEN ON INJECTABLEPROGESTOGEN CONTRACEPTIVESA B Chikosi, M Parasztsak, P JOjwang, J MoodIeyObjective. To demonstrate the effect of depotmedroxyprogesterone acetate (DMPA) and norethisteroneoenanthate (NET EN) on basal prolactin levels with a view toinvestigating the role of progestogen-inducedhyperprolactinaemia in the pathogenesis of galactorrhoea,amenorrhoea and possibly prolactinomas.Design. Descriptive study.Setting. Commercial Centre Family Planning Oinic and KingEdward VIII Hospital, Durban, South Africa.Subjects. Seventy-four women on injectable contraceptivescomprised the study group. Thirty-nine of these women wereon DMPA and 35 on NET EN. The control group comprised62 women. Women with medical conditions or medicationsthat affected prolactin secretion as well as lactating andpregnant women were excluded from the study. Bloodsamples were obtained by venepuncture under controlled,standard conditions. Serum prolactin levels were determinedby enzyme-linked immunosorbent assay.Results. The overall mean serum prolactin level in the studygroup was 266 /lID / ml. In the control group the mean serumprolactin level was 245 /lID / ml. There was no significantdifference between the two groups (P = 0.39). The meanserum prolactin level among women on DMPA was226 /lID / ml compared with 310 /lID / ml among those onNET EN. Basal prolactin levels were significantly increased inwomen on NET EN compared with the control group .(P =0.03). There was no significanfdifference in basal prolactinlevels between the control group and women on DMPA(P = 0.43).Conclusion. The use of NET EN was associated with asignificant increase in serum prolactin levels, although theyremained within the normal range. Consequently NET ENmay cause chronic hyperstimulation of anterior pituitarylactotrophs and may therefore predispose users to thedevelopment of prolactinomas. The risk, however, isprobably minimal.5 Afr Med /1999; 89: 1005-1010.Departmrnt of Obstetrics and Gynaecology and MediCJ21 ResearchCouncil/University of Natal Pregnancy Hypertrnsion Research Unit, DurbanA B Chikosi, MB ChBJ MoodIey, FCOG (SA), FRCOG, MDDepartmrnt of Chemical Pathology, University of Natal, DurbanM Parasztsak, MB ChBP J Ojwang, FRCPath

Blood ordering practices in the management of ectopic pregnancy at Groote Schuur hospital

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Blood ordering practices in the management of ectopic pregnancy at Groote Schuur hospital

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