December 18, 2015
1 min read

Study highlights risk factors of hyponatremia in orthopedic surgery patients

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact

Results from a study cited longer hospital stays and more expensive hospitalizations in orthopedic patients who developed hyponatremia, with greater chances of development with older age, spine surgery, hip arthroplasty and amount of lactated Ringer solution used.

Researchers retrospectively reviewed electronic charts and OR records of 1,067 consecutive orthopedic surgery patients who were aged greater than 21 years and admitted to a tertiary academic medical center between January and December 2010. Within 30 days preoperatively, first day postoperatively and day of hyponatremia diagnosis, investigators recorded patients’ sodium levels. Patients were divided into three groups: normonatremic patients during hospitalization; patients admitted to the hospital with hyponatremia at the time; and patients who developed hyponatremia postoperatively. 

Prevalence of hyponatremia, hyponatremia occurrence timing, length of hospital stay, total hospital cost and discharge disposition were recorded. Factors that correlated with hyponatremia and its effects on clinical outcomes were analyzed with a multivariate logistic regression model.

Findings showed 71 patients developed hyponatremia preoperatively and 319 patients developed hyponatremia postoperatively, of whom 298 patients developed it within 48 hours. Investigators noted there were 304 patients who still had hyponatremia when discharged from the hospital. Patients who developed postoperative hyponatremia were older compared with those who were normonatremic (67.2 years vs. 60.5 years).

Those who developed hyponatremia postoperatively also had, on average, 1.3 days longer length of hospital stay, additional hospital costs of $2,200 more and a higher chance of being discharged to either a skilled nursing or acute rehabilitation facility. Spine surgery (OR = 2.76; 95% CI, 1.63-4.7), hip arthroplasty (OR = 1.76; 95% CI, 1.25-2.48) and amount of lactated Ringer solution used (per 10 mL/kg increase, OR = 1.16; 95% CI, 1.05-1.27) increased the chances of hyponatremia development, according to researchers. by Monica Jaramillo

Disclosures: The researchers report no relevant financial disclosures.