Electrolyte abnormalities and laboratory findings in patients with out-of-hospital cardiac arrest who have kidney disease.

PURPOSES: Although electrolyte abnormalities have been generally considered the major cause of out-of-hospital cardiac arrest (OHCA) in patients with kidney disease (KD), this association has never been prospectively validated.

METHODS: A prospective, observational study was conducted in a tertiary university hospital between January 2008 and December 2009. The study sample consisted of consecutively admitted patients with nontraumatic OHCA. Based on the estimated glomerular filtration rate (eGFR, unit: milliliters per minute per 1.73 m(2)), the enrollees were divided into 3 groups: group A (normal kidney function or mild KD; eGFR, 60.0), group B (moderate KD; eGFR between 15.0 and 59.9), and group C (severe KD; eGFR<15.0 or on dialysis). The laboratory findings of the groups were compared. Two-tailed P values less than .005 were considered significant.

RESULTS: Two hundred thirty-four enrollees (137 were male) were divided into 3 groups: group A (n = 51; 21.8%), group B (n = 128; 54.7%), and group C (n = 55; 23.5%). Compared with the other 2 groups, group C presented significantly higher serum potassium and magnesium and lower pH and hemoglobin level (all P < .005). After stratifications of the significant variables, a post hoc analysis revealed that group C presented significantly higher incidences of hypermagnesemia (Mg >2.5 mmol/L) and severe hyperkalemia (K >6.5 mmol/L) (both P < .005) than the other 2 groups. The odds ratios of the incidence of severe hyperkalemia in group C was 3.37 (95% confidence intervals, 1.46-7.77) compared with group A (50.9% vs 23.5%, P < .005).

CONCLUSIONS: Severe hyperkalemia is common in patients with OHCA who have severe KD and should be considered during resuscitation for these patients.