One-year incidence of hyperosmolar states and prognosis in a geriatric acute care unit.
BACKGROUND
Hyperosmolar syndromes are associated with high mortality rates, yet little is known about their incidence and their prognosis.


OBJECTIVE
To determine the 1-year incidence of hyperosmolar states and the prognostic factors for in-hospital and 1-year mortality.


METHODS
A 6-month prospective cohort study was conducted in a 40-bed acute care geriatric unit and included all patients who developed plasma osmolarity of 320 mosm/l or greater. Age, sex and known cognitive impairment as possible risk factors of hyperosmolarity were assessed. In-hospital and 1-year mortality were calculated and risk factors for death among baseline patient characteristics were sought.


RESULTS
48 (11) of the 436 inpatients in the study were identified as hyperosmolar. Diabetic hyperosmolarity was found in 8 patients. Cognitive impairment was a risk factor for hyperosmolarity (relative risk 2.39, 95% confidence interval 2.18-3.33, p < 0.001), but not age or sex. Infections were accompanied by hyperosmolarity in 30 (62.5). Thirty-five patients (72.9) were bed- or chair-ridden. In-hospital mortality was higher in hyperosmolar patients (35.4) than in the others (16.7%, p = 0.003). Causes of death were infection in 5 (29.4), terminal cachexia in 5, thrombosis in 3, gastric bleeding in 1, renal failure in 2 and heart failure in 1. Functional dependency for mobility was a risk factor for in-hospital mortality but not the degree of hyperosmolarity. One-year mortality was 68.7%. Functional dependency and pressure ulcers were independent predictors of 1-year mortality (p = 0.005 and p = 0.044, respectively).


CONCLUSIONS
Hyperosmolar states occurred in cognitively impaired and dependent patients and resulted in high mortality rates at short and at mid-term. Mortality was related to functional dependency rather than to hyperosmolarity.
Bourdel-Marchasson
Isabelle
I
Département de Gériatrie Henri Choussat, Centre Hospitalo-Universitaire de Bordeaux, Bordeaux, France. isabelle.bourdel-marchasson@chu-bordeaux.fr
Proux
Sebastien
S
Dehail
Patrick
P
Muller
François
F
Richard-Harston
Sandrine
S
Traissac
Thalie
T
Rainfray
Muriel
M
D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003681:Dehydration / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D005602:France / Q000453:epidemiology; D005853:Geriatrics; D006299:Health Services for the Aged / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D009994:Osmolar Concentration; D011379:Prognosis; D011446:Prospective Studies; D016019:Survival Analysis