Vascular Access Profile of Haemodialysis Patients at Kenyatta National Hospital

Abstract

Background There is a rapidly growing population of patients with end stage kidney disease on hemodialysis in Kenya. The vascular access is a hemodialysis patients’ lifeline. Ideal vascular access planning should begin in the early stages of chronic kidney disease before the patient requires dialysis. Decisions surrounding the choice of vascular access and the timing for its’ creation are complex. Descriptive data on the process of referral and timing for access creation, types of access utilized, the processes of access creation, after care and management of access complications, vascular access related morbidity and socioeconomic determinants should be documented in order to inform vascular access practice in Kenya. Objective Document the vascular access profile of haemodialysis patients at Kenyatta national hospital and document the factors that determine their choice of vascular access. Methods This was a hospital based descriptive cross-sectional study that evaluated adult patients undergoing hemodialysis for end stage kidney disease for more than three months at the Kenyatta National Hospital Renal Unit. Consecutive sampling was employed to recruit 80 participants. Eligible participants who gave written consent were interviewed via an investigator administered questionnaire to document vascular access types utilized and the individual participants’ vascular access score as the denominator. Results Between January and March 2021, 80 patients who were undergoing regular hemodialysis for ESKD were invited to participate in this study. The participants were predominantly young persons below forty years of age (50.1%) with a comparable number of male to female participants. The distribution of the incident vascular accesses was the non-tunneled central venous catheter (ntCVC)(77.5%), tunneled central venous catheter (tCVC)(20%) and the arteriovenous fistula (AVF)(2.5%) in descending order of frequency. The distribution of prevalent vascular accesses was tCVC (42.5%), CVC with maturing AVF (20%), AVF (18.8%), ntCVC (17.5%) and bridging CVC in a patient on peritoneal dialysis (1.25%) The AVF was the least used vascular access in either group. The median number of access per participant was two with a range of 1 to 20 (n=235). The vascular accesses participants utilized most during their dialysis vintage was a ntCVC(48.5%). The right internal jugular vein was the most common site used for CVC placement RIJntCVC (25.6%), RIJntCVC (21.8%)while the left brachiocephalic region was the most common location for AVF placement (10.3%). 38.3% of the participants reported having a problem with their current vascular access with the reported vascular access complications included vascular access infection, vascular access dysfunction and vascular access related pain and vascular access bleeding that required transfusion (51.6%, 45.2% and 25.8%, 6.5%) respectively. The mean VAQ score was 17.0. There were significantly better (lower) VAQ scores in participants who had an AVF (9.4, p=0.007), those who were single (13.6,p=0.041) those who had not had a problem with their vascular access in the last one year (14.1, p=0.002) and those were very satisfied with their current VA (11.4 p=0.001).There were lower VAQ scores at the extremes of age, amongst those with tertiary level of education(14.7) and those who had a dialysis vintage of more than 2 years(14.7).There were worse (higher) VAQ score in female participants (19.1) and those who had diabetes mellitus (18.9). The VAQ score was comparable in participants who had an AVF in either the dominant or nondominant arm. Various factors were identified as possible contributors to the choice of vascular access. Most participants were referred late for nephrology and vascular access services. 77.5% reported initiation on HD within three months of being diagnosed with ESKD, 85% were initiated on HD as an emergency while 85% had their incident vascular access placed as an emergency. 75% reported being reviewed by a nephrologist within a 3 month period prior to initiation of HD, 21.3% were reviewed by a nephrologist at least 3 months prior to initiation of HD while 7.5% were reviewed by a vascular access surgeon at least 3 months prior to initiation of HD. Only 7.5% had an AVF attempted prior to initiation of HD. At initiation of HD, 18.8% were not aware of any forms of KRT, 62.5% were only aware of HD and only 7.5% reported being aware of the various vascular access types. 58 (73.1%) of the participants were aware of the advantages of AVFs over CVCs and listed them as having less access related infections, better blood flows, ease of bathing, access longevity, aesthetic appeal and ease of conjugal activities ((n= 58) 93.1%, 81%, 39.7%, 36.2%, 3.4% and 1.75% respectively).Their source of information on KRT and vascular access types was from the dialysis nurses, doctors and fellow patients (78.9%, 73.7% and 23.7% respectively). All the participants reported that their first vascular access was recommended by their doctor. Subsequently, almost a half of them (43.8%) had a change of their vascular access within the first 3 months of initiation of HD because of the need to get a definitive vascular access(56.5%), due to vascular access infections (30.4%), access failure (28.8%) and vascular access extrusion (13%). The most common vascular access converted to was a tCVC (48.9%), followed by ntCVC (37.8%) and AVF least (13.3%). About a fifth (n=17, 21.3%) reported having vascular access related hospitalization in the last one year. The reasons for hospitalization included vascular access infections (61.1%), vascular access bleeding (22.2%) and superior venacava syndrome (11.1%). At the time of the study, 59 participants (73.7%) were using a CVC for HD though majority of them (84.7%) reported having been advised to get an AVF. The reasons listed for not having/ using an AVF included long uncoordinated processes (32%), having a previous AVF that never worked (28%), long surgery waiting times (20%), having a CVC therefore seeing no need for another access (18%), financial constraints (16%), having an AVF that was yet to mature (16%), having unsuitable blood vessels (12%) and feeling that an AVF would interfere with their occupation (4%). About a half of the study participants (n= 38, 47.5%) reported having an AVF placement during their dialysis vintage. Of these, a fifth (18.5%) had an AVF in their dominant arm with resultant discomfort in 36.4% reported as difficulty conducting household chores (75%) and/or changes in sensation (50%). 18 (22.5%) of our participants reported a previous AVF that failed. 2,(11.5%) were offered a corrective procedure and 77.8% were willing to get another AVF. Most participants were satisfied with their current access (83.8%) and felt that their access was easy to use (92.5%). More than half (68.8%) would recommend their current access to a fellow patient. The vascular access most preferred was the AVF (68.8%). 11.3% did not know which vascular access they preferred while 6.3% had no preference. Most participants felt that the nurses preferred an AVF (65%). Conclusion This study demonstrates that most participants were young persons expected to be at the peak of their productivity and hence an optimal vascular access is crucial to their ESKD management and their vascular access health related quality of life. The AVF is the least common vascular access in either incident or prevalent accesses, yet it is the most preferred access by both patients and dialysis nurses and has better VAQ scores. Non tunneled CVC is the predominant incident vascular access type while the tunneled CVC is the predominant prevalent access type and this is most likely due to late referral for nephrology and vascular access care, low levels of predialysis patient education and systemic barriers in vascular access acquisition and maintenance. Individualized vascular access placement should consider the patients’ preference, their comorbidities, previous vascular access experience, their socioeconomic determinants and their vascular access related quality of life. A vascular access coordination team is key to ensure optimal individualized vascular access outcomes.