Long-term outcomes of dialysis-dependent chronic kidney disease patients requiring critical care: an observational matched cohort study

Abstract

Background: The prevalence of dialysis-dependent chronic kidney disease (CKD5D) patients in Australia is increasing.

Aims: To describe the long-term outcome and resource utilisation of CKD5D patients requiring critical care admission.

Methods: Retrospective matched cohort study conducted in the intensive care unit (ICU) of Alice Springs Hospital. CKD5D patients admitted between 1 January 2011 and 31 December 2013 were matched by sex, age, Indigenous status and APACHE III score in a 1:1 ratio with a patient without CKD5D. Primary outcome was mortality censored at 31 December 2018, to allow a minimum 5-year follow up. Secondary outcomes explored resource use including ICU and hospital length of stay (LoS).

Results: During the study period, 178 (9%) admissions were coded as having CKD5D, 148 (83%) of which were successfully matched. CKD5D patients were older (52 vs 49 years, P < 0.01), with more chronic cardiovascular disease (34 vs 23%, P < 0.01). Five-year mortality was similar (49.5 vs 41.5%, P = 0.28), with a significantly longer time to death in the CKD5D cohort (1179 vs 341 days, P < 0.01). CKD5D patients had a shorter median ICU LoS (1.9 vs 3.0 days, P < 0.01) and lower rates of mechanical ventilation (12.2 vs 35.4%, P < 0.01).

Conclusion: CKD5D patients frequently require intensive care during acute illness. While they have an equivalent 5-year survival rate, time to death is longer suggesting mortality is related to chronic disease progression rather than their acute illness. These results suggest the presence of CKD5D in isolation should not be a reason to limit critical care.

Keywords: chronic renal insufficiency; critical care; critical illness; outcome assessment; renal dialysis.