People with acute critical illness have an increased risk of kidney complications and death, finds a study.

"Patients with acute critical illness without apparent underlying renal disease -- a group traditionally considered to be at low risk of renal diseases -- have clinically relevant long-term renal risks," wrote Dr. Shih-Ting Huang and Dr. Chia-Hung Kao of Taichung Veterans General Hospital and China Medical University, Taiwan, respectively.

Most studies have looked at patients with pre-existing kidney disease, while this study looked at data on 33, 613 Taiwanese patients with critical acute illness and no pre-existing kidney disease compared with 63, 148 controls for a medium-term renal outcome.

More than half of the patients (53 per cent) were above 65 years of age and two-thirds (67 per cent) had high blood pressure. Patients who had experienced acute kidney illness were at an increased risk of renal complications, developing chronic kidney disease and end-stage renal disease, with septicemia and septic shock being the strongest risk factors.

Of the critically ill patients in the study, 335 developed an end-stage renal disease, with a rate of 21 per 10 000 person-years compared with 4.9 per 10 000 person-years in the control group. Patients who developed chronic kidney disease and end-stage renal disease were at a higher risk of death. The authors have suggested clinicians to monitor kidney functions at 30-90 day intervals in patients with acute critical illness without preexisting renal disease and then at least on a yearly basis, afterward. The study has been published in the Canadian Medical Association Journal (CMAJ).