Analysis of the vascular access service for patients on haemodialysis in Livingstone Hospital.

BACKGROUND: Reliable vascular access is key to sustainable haemodialysis treatment. Guidelines recommend an arteriovenous fistula (AVF) as the preferred modality in preference to arteriovenous grafts (AVGs) or central venous catheters (CVCs). There are limited data on vascular access in sub-Saharan Africa. This study aimed to evaluate the vascular access used in a South African tertiary hospital and identify problems with achieving the recommended access goals. METHODS: A cross-sectional analysis was performed of the haemodialysis programme at Livingstone Tertiary Hospital. Current and initial vascular access used, timing until the creation of permanent access, and any complications experienced were recorded. RESULTS: CVCs were used in 56% of subjects, 38% were using an AVF and 5% were using an AVG. Only 12% of the group had no AVF attempt. The overwhelming majority (95%) had dialysis initiated with a CVC. The rate of pre-emptive AVF creation was low and a delay in AVF creation was seen in 63% of patients. Central venous stenosis or occlusion was present in 26% of patients and likely due to prior or current CVC use. CONCLUSIONS: The prevalence of CVC use was high and there were significant delays to AVF creation. High rates of central venous stenosis compromise future AVF use and are likely due to prolonged CVC use. Changes needed to improve the vascular access service include a multidisciplinary access clinic, dedicated theatre list, vascular access co-ordinator and further data collection to continually evaluate the vascular access service.

Risk factors and outcomes of acute kidney injury in South African critically ill adults: a prospective cohort study.

BACKGROUND: There is a marked paucity of data concerning AKI in Sub-Saharan Africa, where there is a substantial burden of trauma and HIV. METHODS: Prospective data was collected on all patients admitted to a multi-disciplinary ICU in South Africa during 2017. Development of AKI (before or during ICU admission) was recorded and renal recovery 90 days after ICU discharge was determined. RESULTS: Of 849 admissions, the mean age was 42.5 years and mean SAPS 3 score was 48.1. Comorbidities included hypertension (30.5%), HIV (32.6%), diabetes (13.3%), CKD (7.8%) and active tuberculosis (6.2%). The most common reason for admission was trauma (26%). AKI developed in 497 (58.5%). Male gender, illness severity, length of stay, vasopressor drugs and sepsis were independently associated with AKI. AKI was associated with a higher in-hospital mortality rate of 31.8% vs 7.23% in those without AKI. Age, active tuberculosis, higher SAPS 3 score, mechanical ventilation, vasopressor support and sepsis were associated with an increased adjusted odds ratio for death. HIV was not independently associated with AKI or hospital mortality. CKD developed in 14 of 110 (12.7%) patients with stage 3 AKI; none were dialysis-dependent. CONCLUSIONS: In this large prospective multidisciplinary ICU cohort of younger patients, AKI was common, often associated with trauma in addition to traditional risk factors and was associated with good functional renal recovery at 90 days in most survivors. Although the HIV prevalence was high and associated with higher mortality, this was related to the severity of illness and not to HIV status per se.

Vascular calcification is not associated with increased ambulatory central aortic systolic pressure in prevalent dialysis patients.

INTRODUCTION: Central aortic systolic pressure (CASP) strongly predicts cardiovascular outcomes. We undertook to measure ambulatory CASP in 74 prevalent dialysis patients using the BPro (HealthStats, Singapore) device. We also determined whether coronary or abdominal aortic calcification was associated with changes in CASP and whether interdialytic CASP predicted ambulatory measurement. METHODS: All patients underwent computed tomography for coronary calcium score, lateral abdominal radiography for aortic calcium score, echocardiography for left ventricular mass index and ambulatory blood pressure measurement using BPro calibrated to brachial blood pressure. HealthStats was able to convert standard BPro SOFT(®) data into ambulatory CASP. RESULTS: Ambulatory CASP was not different in those without and with coronary (137.6 vs 141.8 mmHg, respectively, p = 0.6) or aortic (136.6 vs 145.6 mmHg, respectively, p = 0.2) calcification. Furthermore, when expressed as a percentage of brachial systolic blood pressure to control for peripheral blood pressure, any difference in CASP was abolished: CASP: brachial systolic blood pressure ratio = 0.9 across all categories regardless of the presence of coronary or aortic calcification (p = 0.2 and 0.4, respectively). Supporting this finding, left ventricular mass index was also not different in those with or without vascular calcification (p = 0.7 and 0.8 for coronary and aortic calcification). Inter-dialytic office blood pressure and CASP correlated excellently with ambulatory measurements (r = 0.9 for both). CONCLUSION: Vascular calcification was not associated with changes in ambulatory central aortic systolic pressure in this cohort of prevalent dialysis patients. Inter-dialytic blood pressure and CASP correlated very well with ambulatory measurement.