P1325VASCULAR ACCESS OUTCOMES IN A FRAIL HAEMODIALYSIS POPULATION
Authors: Radley Alice , Wong Wan , Collidge Tara , Thomson Peter 
Published: June 2020

Abstract

Background and Aims
Current guidelines recommend the pursuit of arteriovenous (AV) access over central venous catheter (CVC) access in haemodialysis (HD) populations. The limitations of this approach are increasingly recognised, and are particularly relevant when considering frail patients with relatively high levels of comorbidity and limited life expectancy. In such patients AV access may incur more invasive procedures, whereas CVC access may incur heightened risks of infection.
This study aimed to evaluate the association between HD access modality and access complications, hospitalisation and mortality in a cohort of HD patients with frailty.

Method
We performed a retrospective analysis of prospectively recorded data from the Strathclyde Electronic Renal Patient Record concerning HD patients from 01/10/2017 to 21/09/2019. HD patients with a Rockwood clinical frailty scale (CFS) ≥6 were identified with baseline demographic data being recorded from date of first CFS ≥6 to census date 21/09/19 or death. We recorded the first vascular access modality at study inception and the modality at the time of census or death.
Episodes of TCVC associated sepsis were determined using both clinical diagnosis in patient case records and positive blood cultures. Episodes were regarded as separate where positive blood cultures occurred ≥14 days apart. An inpatient admission was regarded as a discharge date ≥24 hours following admission. These were then further categorised as unscheduled or elective.

Results
139 patients were identified with CFS ≥6. Median age was 72 years and 51% were female. Median follow-up was 1.1 years with total 50861 observed HD days. 52.3% patients were deceased at census.
Table 1 illustrates vascular access modality at initial CFS. CVC accounted for the greatest proportion of dialysis access days (50.3%) compared to AVF (40.7%) and AVG (8.9 %).
There was no significant difference in mortality between vascular access modalities over the follow-up period (50.7% CVC; 55% AVF; 54.5% AVG, p=0.18).
In total, 5244 HD exposed days (10.3%) were spent as an inpatient during follow-up, of which 5120 (98%) were unscheduled and 119 (2%) were elective.
The AVG group had the highest rate of inpatient bed days (138/1000 HD days) when compared to CVC (107/1000 HD days) and AVF (94/1000 HD days). Both AVG and CVC were associated with more inpatient bed days than AVF (p&lt;0.0001 for each).
Patients who started with CVC and transitioned to AV access had a rate of 86/1000 HD days. This was significantly lower than those who remained CVC throughout (p=0.0001).
There were 24 recorded events of CVC associated sepsis during follow-up, occurring at a rate of 0.8 per 1000 HD days. Rates of CVC associated sepsis were similar between CFS 6 (0.6 per 1000 HD days) and CFS 7 (1.1 per 1000 HD days), p=0.21. The CVC associated staphylococcus aureus bacteraemia (SAB) rate for the overall population was 0.2 per 1000 HD days.
AVG sepsis occurred at a rate of 0.2 per 1000 HD days and there were no incidences of AVF sepsis in those who continued with AVF throughout the follow-up period.

Conclusion
CVC was the most prevalent access modality in this frail HD population. Rates of CVC associated sepsis and SAB were similar to published bloodstream infection rates and existing local data (Murray et al QJM 2014). Although absolute events were low, increasing frailty from CFS 6 “moderately frail” to CFS 7 “severely frail” did not appear to influence rate of CVC associated sepsis. Patients with CVC and AVG had greater inpatient bed days than those with AVF. Transitioning from CVC to AV access reduced inpatient bed days. However, the choice of vascular access modality did not influence mortality overall.