Title : An association of hyponatremia with inpatient falls
Purpose: The purpose of the study was to examine hyponatremia in the hospital setting to determine if it was associated with falls.
Methods: To determine if hyponatremia was associated with falls that occurred within the hospital, the author retrospectively reviewed all fall cases of patients occurring over a six-month period and manually abstracted data. The sample was all adult patients (18 years of age and older) who fell during a six-month period excluding Emergency Department patients, prisoners, obstetric and pediatric patients, patients whose medical records were not located after three attempts, and patients who did not have a serum sodium result documented during hospitalization.This resulted in a sample size of 163.
All serum sodium levels for each patient’s hospitalization were abstracted and mapped against the date of the fall. The number of patients who fell and had normal serum sodium and those who fell and had hyponatremia during their admission were calculated. A chi square test of goodness of fit was performed to determine if there was a significant difference in the proportion of patients who fell and were hyponatremic and those who fell and would have been expected to develop hyponatremia as documented in the literature during hospitalization.
Results: Of the patients who fell, 74 (45.4%) were hyponatremic during their hospital admission. The proportion of those who were hyponatremic (45.4%) was greater than the highest proportion expected (30%). This was statistically significant using the chi square test of goodness of fit, X2 (1, N=163) = 18.24, p <0.01. Of those who fell and were hyponatremic (N=74), 37(50%) were hyponatremic within 48 hours prior to the fall or the day of the fall and another 10 patients became hyponatremic the day after the fall.
Conclusions: This study found that hyponatremia (serum sodium <136 mM/L) was associated with falls among hospitalized patients although more research would be needed utilizing different research designs to determine specific relationships. Many of the falls occurred within 48 hours of the patient being documented as hyponatremic or the hyponatremia documented within 24 hours after the fall. This seemed to be a critical time period for those who fell and should be investigated further. Given the association between hyponatremia and falls, clinicians should consider having serum sodium levels incorporated into fall assessments as a more objective criterion to determine fall risk or it could be used as a standalone, at the moment, alert to heighten awareness and help prevent falls.