A new study published by The Journal of Bone and Joint Surgery examined the prevalence, timing, causes and outcomes of hyponatremia in hospitalized orthopedic surgery adult patients.
Here are five key points from that study:
1. 1,067 medical records of consecutive orthopedic surgery patients admitted to a tertiary academic institution were evaluated. These records were reviewed to investigate hyponatremia (a condition that occurs when the level of sodium in the blood is too low) that had either been present on hospital admission or had developed postoperatively.
2. The primary outcomes were the prevalence and timing of, risk factors for and presentation with or development of hyponatremia.
3. The secondary outcomes were length of hospital stay, total hospital cost and discharge disposition.
4. The researchers found that:
- Of the 1,067 patients studied, 71 of them (7 percent) had preoperative hyponatremia, and 319 of them (30 percent) developed hyponatremia postoperatively. Of the latter category, 298 patients (93 percent) developed hyponatremia within 48 hours postoperatively.
- Compared to patients with normonatremia (normal level of sodium in the blood), on average, those presented with hyponatremia were older (67.2 years versus 60.5 years), had longer hospital stays (4.6 days versus 3.3 days), incurred higher hospital costs ($19,200 versus $17,000) and were more likely to be discharged to an extended-care facility.
- On average, those with developing hyponatremia postoperatively resulted in a longer hospital stay (3.7 days versus 3.3 days) and greater hospital cost ($18,800 versus $17,000).
5. The study concluded that hyponatremia in orthopedic patients is associated with longer, costlier hospitalizations, and the factors that significantly increased the risk of developing postoperative hyponatremia were older age, spine fusion, hip arthroplasty and the amount of lactated Ringer solution used.