Acute renal failure: in-hospital mortality was high.

Clinical bottom line (level 4)

  1. Around 5% of medical and surgical in-patients developed acute renal failure. A third died.
  2. About half of cases of acute renal failure were due to iatrogenic causes.
  3. Patients were at an increased risk of dying if they:
    • had a creatinine rise 264 µ mol/l or more (NNF = 2 for unknown)
    • developed oliguria (NNF = 3 for unknown)
  4. Few patients went on to need long term dialysis.
Hou et al: American Journal of Medicine 1983; 74: 243-248
Expires July 2003

The study

Inception cohort study with objective outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital, USA

109 patients (aged ?, ?% male) renal insufficiency which developed during hospital admission, defined as: increase of >44 µ mol/l for patients with baseline creatinine <168 µ mol/l; increase of >88 µ mol/l for patients with baseline creatinine 177 to 433 µ mol/l; increase of 133 µ mol/l for patients with baseline creatinine >442 µ mol/l

Excluded if
  • admitted for management of acute renal failure or long-term haemodialysis



    • Factors studied:
  • mortality, long term dialysis
  • oliguria
  • creatinine rise 264 µ mol/l or more




    • 100% followed for until discharge
    Outcomes studied:
  • acute renal failure in hospital
  • mortality
  • long term dialysis
  • decreased renal perfusion documented decline in blood pressure to less than 90/60; weight loss accompanied by physical examination findings of volume contraction; clinically evident congestive heart failure with improvement in renal function following treatment of heart failure
  • major surgery
  • contrast media administration
  • aminoglycoside administration
  • hepatorenal syndrome
  • multifactorial
  • obstruction
  • vasculitis
  • other or unknown

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    acute renal failure in hospital until discharge 109/2216 4.9%
    (4.0% to 5.8%)
    mortality until discharge 32/109 29%
    (21% to 38%)
    long term dialysis until discharge 3/109 2.8%
    (0.0% to 5.8%)
    decreased renal perfusion until discharge 54/130 42%
    (33% to 50%)
    major surgery until discharge 23/130 18%
    (11% to 24%)
    contrast media administration until discharge 16/130 12%
    (6.7% to 18%)
    aminoglycoside administration until discharge 9/130 6.9%
    (2.6% to 11%)
    hepatorenal syndrome until discharge 5/130 3.9%
    (0.54% to 7.2%)
    multifactorial until discharge 4/130 3.1%
    (0.11% to 6.1%)
    obstruction until discharge 3/130 2.3%
    (0.0% to 4.9%)
    vasculitis until discharge 2/130 1.5%
    (0.0% to 3.7%)
    other or unknown until discharge 14/130 11%
    (5.4% to 16%)

    prognostic factor for
    mortality     		time to outcome unadjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    oliguria until discharge 3.14
    (1.68 to 5.89)     		3
    (1 to 9)
    creatinine rise 264 µ mol/l or more until discharge 4.16
    (2.43 to 7.13)     		2
    (1 to 5)

    Comments

    1. Iatrogenic factors accounted for 55% of hospital-acquired renal failure.
    2. Since the patients studied were admitted to a tertiary care hospital, their level of complexity and comorbidity may be greater than that encountered in a community setting, and their mortality correspondingly higher.

    Citation

    1. Hou SH, Bushinsky DA, Wish JB, et al: Hospital-acquired renal insufficiency: a prospective study. American Journal of Medicine 1983; 74: 243-248
    Search Terms: reference list of review articles
    Contributor: Catherine Clase, Chris Ball and Clare Wotton, April 2000
    Reviewer:

    Clinical Question.
    Patient renal insufficiency
    Intervention or Exposure prognostic factors
    Outcome mortality