Study finds, Sodium Abnormalities as an Independent Predicto
Electrolyte levels are commonly obtained as part of the preoperative workup for total joint arthroplasty (TJA). There exists an interplay between electrolyte abnormalities and outcomes.

The National Surgical Quality Improvement Program was queried for primary, elective total hip and knee arthroplasties (THA, TKA). 3 patient groups were compared: normal (control), hyper-, and hyponatremia. The primary outcomes were length of stay (LOS) and 30-day adverse events: complications, readmissions, reoperations, and mortality.

--244,538 TKAs and 145,134 THAs were analyzed. The prevalence of hypo- and hypernatremia were 6.9% and 1.0% respectively.

--After controlling for any baseline differences, hypernatremia was an independent predictor of ventilation more than 48 hours, unplanned intubation, cardiac arrest, pneumonia, C. difficile infection, LOS more than 2 days and mortality.

--Similarly, hyponatremia was an independent predictor of LOS more than 2 days, readmission, reoperation, surgical site infections, and transfusion.

As the focus of TJA continues to shift towards value-based payment models and outpatient surgery, caution should be exercised in patients with abnormal preoperative sodium levels, particularly hypernatremia, due to significantly increased risk of prolonged LOS and 30-day adverse events.