Microalbuminuria in the intensive care unit: Clinical correlates and association with outcomes in 431 patients.
OBJECTIVE
Comparison of urine albumin within 6 hrs of intensive care unit (ICU) admission with demography, clinical classification, outcome, inotrope/vasopressor requirement, clinical assessment of mortality risk, and Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores.


METHODS
Urine albumin-creatinine ratio (ACR) was measured on ICU admission (ACR 1) and after 4-6 hrs (ACR 2).


METHODS
A 17-bed general ICU in a university teaching hospital.


METHODS
Unselected medical (206) and surgical (225) patients recruited prospectively.


METHODS
None.


RESULTS
Bedside urine ACR was measured by nurses using a Bayer DCA 2000 analyzer and expressed in mg/mmol (reference range <2.3). ACR 1 in medical and surgical patients was 15.5 (12.4-19.5) and 8.2 (5.9-11.1) mg/mmol, respectively (p = .0002), and ACR 2 was 9.0 (5.8-12.5) and 4.6 (3.6-5.3), respectively (p < .0001). For all patients, median (95% confidence interval) ACR fell from 11.2 (8.7-13.2) to 5.4 (4.7-6.8) mg/mmol 4-6 hrs after ICU admission (p < .0001). ACR 1 for nonsurvivors (n = 90) and survivors (n = 341) was 16.1 (11.2-21.3) and 8.8 (6.9-11.9), respectively (p = .0002) and ACR 2, 12.4 (8.2-18.9) and 4.8 (3.9-5.4), respectively (p < .0001). In both medical and surgical patients who died on the ICU, median ACR failed to decrease significantly following admission. ACR1 and ACR 2 were higher in patients who required inotropic or vasopressor support and correlated with duration of therapy. ACR 1 and 2 were inversely correlated with mean Po2/Fio2 ratio 48 hrs after ICU admission and positively correlated with duration of mechanical ventilation and ACR 1 with ICU stay. ACR 2 predicted mortality and ACR 1 inotrope requirement independent of clinical mortality risk assessment and APACHE II and SOFA scores.


CONCLUSIONS
Urine albumin changes rapidly within the first 6 hrs following ICU admission and predicts ICU mortality and inotrope requirement as well as or better than APACHE II and SOFA scores. Serial urine albumin measurement may provide a means of monitoring the microvascular effects of systemic inflammation.
Gosling
Peter
P
Department of Clinical Biochemistry, University Hospital Birmingham NHS Foundation Trust, Birmingham, UK.
Czyz
John
J
Nightingale
Peter
P
Manji
Mav
M
D018806:APACHE; D000368:Aged; D000369:Aged, 80 and over; D000419:Albuminuria; D002316:Cardiotonic Agents / Q000627:therapeutic use; D003404:Creatinine / Q000652:urine*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010100:Oxygen / Q000097:blood; D010343:Patient Admission; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012121:Respiration, Artificial; D018570:Risk Assessment; D012720:Severity of Illness Index; D013997:Time Factors; D006113:United Kingdom; D014662:Vasoconstrictor Agents / Q000627:therapeutic use
D002316:Cardiotonic Agents; D014662:Vasoconstrictor Agents; D003404:Creatinine; D010100:Oxygen