Abstracts of Posters Presented at the International Anesthesia Research Society; 72nd Clinical and Scientific Congress; Orlando, FL; March 7-11, 1998: Obstetric Anesthesia
Introduction: HIV infection is associated with multiple hematologic abnormalities. Thrombocytopenia may occur both in the early asymptomatic stage, as well as later in the advanced AIDS Related Complex stage. Thrombocytopenia of the most recently HIV-infected patients generally relates to an accelerated platelet destruction by autoantibodies, which subsequently cause platelet sequestration in the spleen. Thrombocytopenia associated with clinical AIDS may on the other hand relate more to a production defect.  This study investigated platelet count and function as assessed by thromboelastograph (TEG) in the HIV-infected parturient.
Methods: This prospective cohort controlled study was approved by the institutional review board of Emory University. The study, population consisted of parturients delivering in their third trimester at Grady Memorial Hospital. Laboratory studies drawn prior to delivery included: platelet count, ELISA (and subsequent confirmation with Western Blot), CD4 levels, urine drug screen and TEG. Whole blood was collected in citrated tubes and the stoichiometrically re-calcified TEGs were run on a Haemoscope 2000D. Exclusionary criteria were preeclampsia, placental abruption, septicemia and cocaine abuse. Data collected included: parity, maternal age and race, estimated gestational age, the presence of infectious diseases, and CD4 counts. Data analysis used a two-tailed Student's t-Test, analysis of variance, or Chi-squared, as appropriate. P<or=to 0.05 was considered significant.
Results: A total of 551 patients were enrolled in the study. Of these, 20 tested HIV-positive while the remaining tested HIV-negative. The average CD4 count was 508 +/- 162 cells/mm3 in the HIV-positive parturients. 12 out of the twenty HIV-infected parturients were treated several months prior to delivery with Zidovudine. Further data is listed below. (Table 1)
Discussion: The HIV-infected parturient is in a precarious position hematologically. While pregnancy in its own right may lower platelet count through a dilutional effect, an asymptomatic early HIV infection may as well. Paradoxically, as clinical AIDS develops, the platelet count may normalize. In an attempt to diminish the untoward effects of pregnancy on HIV-infection, as well as the effects of HIV-infection on the pregnancy and possibly attenuating perinatal AIDS transmission, Zidovudine is prescribed. While Zidovudine may decrease the rate of platelet destruction, the drug may cause further bone marrow suppression.  In this prospective study, as compared to the non HIV-infected parturient, we found no difference in either platelet count or function in the asymptomatic HIV-infected patient, whether on Zidovudine or not.
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