Browsing by Author "Steadman, Carl"

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    The prevalence of thrombocytopenia at a primary care HIV clinic in South Africa - possible implications for neuraxial anaesthesia
    (Stellenbosch : Stellenbosch University, 2017-12) Steadman, Carl; Smit, Marli; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Anaesthetics and Critical Care.
    ENGLISH ABSTRACT: South Africa has a high incidence of Human Immunodeficiency Virus (HIV) infection, and many of these patients will require surgery during their lives. The exact prevalence of thrombocytopenia in South African, HIV-infected patients (naïve/non anti-retroviral therapy naïve) are unknown. The reported global prevalence of thrombocytopenia in HIV positive patients ranges between 5.5 to 50% 17, 18. Neuraxial anaesthesia is contraindicated in patients with platelet counts of <75 x 109/L, due to the risk of neuraxial haematoma. The large variation in practice (in South Africa) in terms of preoperative special investigations (especially platelet count) in this patient population suggests that patients are either under investigated, or that unnecessary investigations are performed; with cost and time implications. This wide range in thrombocytopenia prevalence, together with the anaesthetic implications secondary to thrombocytopenia was the motivation behind us conducting an audit to determine the prevalence of thrombocytopenia in HIV positive patients. Our primary outcome was to determine the prevalence of thrombocytopenia in HIV-positive patients attending a primary care HIV clinic in the Western Cape, South Africa. Secondary outcomes were to: 1. Determine if there is any correlation between CD4 count and platelet count. 2. Determine what the influence of ART on platelet count is. 3. To make informal proposals regarding pre-operative special investigations (specifically platelet count) in the HIV positive patients. Our study, consisting of 1,410 patients, provided the following important results: The median CD4 count was 281 +/- 199 cells / mm3. Thirty-one percent of patients had a CD4 count of < 200 cells / mm3. The median platelet count was 270 +/- 100x109/L. The platelet count was < 150 x 109/L (thrombocytopenia) in 6.5%, and < 75 x 109 /L (severe thrombocytopenia) in 0.7% of participants. Thrombocytopenia was more common in patients with a CD4 count < 200 cells/mm3 (p <0.001) and in ART naïve patients (p = 0.02). However, there was no connection between severe thrombocytopenia and a CD4 count of < 200 cells / mm3 (p = 0.36) or ARV naivety (p = 0.66) Infection and malignancy had no significant impact on thrombocytopenia (p = 0.66, Fischer's exact 0.3) nor severe thrombocytopenia (p = 0.99, Fischer's exact 0.5). Conclusion: In this descriptive study, we found that the prevalence of severe thrombocytopenia to be very low (0.7%). We cannot make statistically supported deductions regarding this result because the prevalence of thrombocytopenia in the general population is unknown, and our study did not have a control group. However, we will propose that the following be kept in mind regarding preoperative special investigation decision making in HIV positive patients: 1. The incidence of neuraxial hematomas has not increased in conjunction with the increase in HIV positive patients, 2. The costs associated with special investigations. 3. The low prevalence of severe thrombocytopenia. 4. The lack of literature to support a safe cut-off for platelet count for neuraxial anaesthesia.