Acute renal failure (ARF) in the Intensive Care Unit (ICU) is perceived as associated with a high mortality. We retrospectively analysed the RIPUG database of 26,689 patients admitted to 21 ICUs in the UK between June 1989 and September 1996. The incidence of ARF was 9%. Patients who were admitted with ARF (n = 1393) had a lower mortality than those who developed ARF (n = 1001) during their stay in the ICU (40.8% versus 50.7%, P < 0.001). We determined the maximum number and specific combinations of organ failures (OF) at any time and the number and specific combinations within 48 hours of death or discharge and the associated outcomes (Table). The mortality rates of all patients with any single, two or three OFs served as references for comparison with the mortality rates of specific types or combinations. Forty-four percent of patients who died in the ICU had a serum creatinine of < 200 μmol/l.
Table.
| Maximum OFs at any time | OFs within 48 hours of death/discharge | ||||||
|---|---|---|---|---|---|---|---|
| Type of OF | n | ICU mortality (%) | P | n | ICU mortality (%) | P | |
| Any 1 OF | 737 | 16.3 | |||||
| ARF | 608 | 9.4 | 517 | 11.6 | < 0.05 | ||
| CVS | N/A | N/A | 20 | 45.0 | < 0.001 | ||
| RESP | N/A | N/A | 123 | 34.2 | < 0.001 | ||
| 2 OFs | 713 | 35.6 | 555 | 55.0 | |||
| CVS + RESP | 23 | 43.5 | NS | 30 | 73.3 | < 0.05 | |
| CVS + ARF | 183 | 47.5 | < 0.01 | 320 | 87.8 | < 0.001 | |
| RESP + ARF | 297 | 36.0 | NS | 371 | 85.2 | < 0.001 | |
| GI + ARF | 89 | 13.5 | < 0.001 | 94 | 70.2 | < 0.01 | |
| GI + RESP | 28 | 35.7 | NS | 30 | 60.0 | NS | |
| NEURO + ARF | 36 | 41.7 | NS | 31 | 45.2 | NS | |
| 3 OFs | 685 | 66.0 | 482 | 83.4 | |||
| CVS + RESP + ARF | 345 | 78.8 | < 0.001 | 243 | 91.0 | < 0.01 | |
| CVS + RESP + GI | 10 | 80.0 | NS | 11 | 100 | NS | |
| CVS + NEURO + ARF | 40 | 77.5 | NS | 36 | 86.1 | NS | |
| RESP + NEURO + ARF | 38 | 65.8 | NS | 38 | 81.6 | NS | |
CVS = cardiovascular failure; RESP = respiratory failure; GI = gastrointestinal failure; HAEM = haematological failure; NEURO = neurological failure; N/A = not applicable. (Only Groups with 10 patients included.)
Patients with ARF alone had a significantly lower mortality than patients with any other single OF. This superior outcome was abolished when ARF occurred in combination with other failed organ systems. The majority of patients die with ARF rather than from ARF.