Acquired hypernatraemia is an independent predictor of mortality in critically ill patients.
This study reports the incidence and associated mortality of acquired hypernatraemia (Na > 150 mmol x l(-1)) in a general medical/surgical intensive care unit. Patients admitted over a 5-year period with normal sodium values were eligible for inclusion; exclusions were made for burn/neurosurgical diagnoses and for hypertonic saline therapy. From 3475 admissions (3317 patients), 266 (7.7%) episodes of hypernatraemia were observed. Hospital mortality was 33.5% in the hypernatraemic group and 7.7% in the normonatraemic group (p < 0.001). Acquired hypernatraemia was an independent risk factor for in-hospital mortality (OR 1.97, 95% CI 1.37-2.82, p < 0.001). Intermediate sodium levels (145-150 mmol x l(-1)) were associated with increased mortality (OR 1.42, 95% CI 1.02-1.98). Uncorrected sodium at discharge (p = 0.001) and peak sodium (p = 0.001) were better predictors of mortality than time to onset (p = 0.71) and duration of hypernatraemia (p = 1.0). Hypernatraemia avoidance is justified, but determinants of hypernatraemia and benefits of targeted treatment strategies require further elucidation.
O'Donoghue
S D
SD
Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia. Steve_O'Donoghue@health.qld.gov.au
Dulhunty
J M
JM
Bandeshe
H K
HK
Senthuran
S
S
Gowardman
J R
JR
D000328:Adult; D000368:Aged; D016638:Critical Illness / Q000401:mortality*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D006955:Hypernatremia / Q000097:blood / Q000175:diagnosis / Q000209:etiology / Q000401:mortality*; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011793:Queensland / Q000453:epidemiology