Cadmium excretion predicting hospital mortality and illness severity of critically ill medical patients

OBJECTIVE:: To determine the prognostic value of day 1 urine excretion of cadmium (1st DUE-Cd) for predicting outcomes in intensive care unit (ICU) patients. DESIGN:: Prospective study. SETTING:: ICUs in Chang Gung Memorial Hospital, Lin-Kou Medical Center, Taiwan, ROC. PATIENTS:: Two hundred one ICU patients. INTERVENTIONS:: Urine and blood samples were taken within 24 hours after admission. MEASUREMENTS AND MAIN RESULTS:: Disease severity, hospital mortality, and number of organ failures were evaluated in each medical ICU patient. Stepwise multiple linear regression analysis indicated that a history of chronic hepatitis, serum albumin, and glutamic-pyruvic transaminase were significantly related to 1st DUE-Cd after adjusting for other related variables. Cox multivariate analysis revealed that serum blood urea nitrogen level and ICU 1st DUE-Cd were significantly related to hospital mortality after other risk factors and scoring systems were adjusted. Each 1-μg increase in ICU 1st DUE-Cd was associated with a 7% increase in hospital mortality rate. All patients with poisoning magnitude of cadmium excretion (>10 μg/day) died, except one and those with normal cadmium excretion survived. Chi-square values of the Hosmer-Lemeshow goodness-of-fit test were 6.936 (p = 0.544), and area under the receiver operating characteristic curve was 0.868 (95% confidence intervals: 0.82-0.92) for ICU 1st DUE-Cd. CONCLUSIONS:: The ICU 1st DUE-Cd may predict hospital mortality in critically ill medical patients. Because of excess mortality and relatively small sample size, the predictive role of DUE-Cd needs further external validation.