Date of Award
Doctor of Philosophy
School of Nursing and Midwifery
Dr Nick Gibson
Dr Mandy Towell-Barnard
Title: Ultrasound measurements on the inferior vena cava (IVC-US) by renal nursing staff for assessment and management of intravascular volume status in haemodialysis patients.
Aims: The primary aim of this thesis was to provide evidence that renal nurses could safely and efficiently perform IVC-US on haemodialysis patients to obtain objective assessment of intravascular volume status and potentially reduce adverse events and morbidity. The secondary aims for this study were: (1) conduct a systematic literature review to identify evidence if renal nurses have previously used this method for intravascular volume assessment; (2) teach a renal nurse through a staged educational programme, guided by a medically trained ultrasonographer, a sonologist, to gain competency in ultrasound image acquisition and interpretation of the scans; (3) measure the prevalence of any form of intradialytic hypotension in a satellite haemodialysis clinic over a three-month period and (4) attain concurrent IVC-US and bioimpedance spectroscopy measurements on 30 patients during their haemodialysis treatment and to compare these findings with their intravascular volume status using the traditional clinical nursing assessment method.
Materials and Methods: To achieve this primary aim, this thesis was separated into multiple phases. First, a systematic literature review of medical and nursing databases was performed to summarise the use of IVC-US in haemodialysis patients by renal nurses. The second phase involved a retrospective data analysis, where the prevalence rate of nurse-documented fluid related intradialytic hypotensive events was measured and a Generalised Estimating Equation (GEE) model was used to predict the likelihood of any form of intradialytic hypotension or postdialytic overhydration. In the next phase a four-step educational programme was developed in collaboration with an expert sonologist, guiding the renal nurse through the process of skill acquisition and accurate fluid assessment based on nurse-performed IVC-US scans. Following this phase, and after receiving theoretical training and performing 100 proctored scans, the renal nurse then performed 60 IVC-US scans independently, which were subsequently assessed by two sonologists, resulting in a cross-sectional interrater study, confirming competency. The final phase of the thesis consisted of a simulative pilot study, where 30 haemodialysis patients were assessed during three intradialytic moments of a single session on their intravascular volume status with IVC-US.
Results: The systematic literature review revealed that there is a paucity of knowledge regarding renal nurses and IVC-US. The 3-month data analysis has shown that intradialytic hypotension (IDH) was still the most common adverse intradialytic event with 13.1% of all treatments affected. The renal nurse mastered the educational programme and was deemed competent by the experts. Finally, the simulative pilot study revealed that if IVC-US had been performed and indicated intravascular hypovolemia, patients had a 14-fold chance to experience subsequent IDH events. An algorithm using IVC-US combined with bioimpedance spectroscopy (BIS) and mean arterial pressure (MAP) revealed a sensitivity of 95% and a specificity of 100% for the prevention of IDH.
Conclusions: This thesis demonstrates the obvious need for more objective and reliable fluid assessment methods in the haemodialysis population to improve clinical outcomes. Most importantly, it has been shown that renal nurses can master the skill to perform IVC-US and that IVC-US is a useful and reliable method of fluid assessment. Performing IVC-US is a transferrable skill and has potential to be preventative for intradialytic hypotension if added to the clinical fluid assessment routine by renal nurses. It has potential to change clinical practice and policy in future, but further research studies are needed to provide evidence for this.
Access to Chapter 6 of this thesis is not available.
Parts of the thesis which featured copies of published articles are also not included. Links to the omitted items are available in Related Publications.
Steinwandel, U. (2018). Ultrasound measurements on the inferior vena cava by renal nursing staff for assessment and management of intravascular volume status in haemodialysis patients. https://ro.ecu.edu.au/theses/2152