Abstract
Introduction
This study was designed to evaluate the effect of discharge timing on 30-day major and minor complications in patients undergoing total knee arthroplasty (TKA) while adjusting for other variables.
Methods
Patients 18 years and older undergoing TKA between the years of 2005 and 2016 were identified from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP). Patients whose length of stay (LOS) was >4 days were excluded. Patient demographics, anesthesia type, length of operation and hospital stay, as well as 30-day major and minor complications were collected from the database. Chi square tests were utilized to compare the unadjusted rates of complications between patients whose LOS was 0, 1, 2, and 3–4 days. Multivariable regression was utilized to evaluate the effect of LOS on complication rates, while adjusting for age, American Society of Anesthesiologist (ASA) class, type of anaesthesia, functional status, comorbidities, sex, steroid/immunosuppressant use, body mass index (BMI), diabetes, length of operation and smoking status.
Results
A total of 198,191 TKA patients were identified (average age 66 ± 10 years). Average LOS was 2.5 ± 0.81 days. Of these patients, 1,667 (0.84%) were discharged the day of surgery, while 16,186 (8.17%) were discharged one-day post-surgery, 63,540 (32.06%) were discharged on day two, and 115,471 (58.25%) were discharged between 3 and 4 days post-surgery.
Unadjusted rates of complications were significantly higher for patients who were discharged on the day of surgery (2.64%), or those whose LOS was 3–4 days (2.78%) compared to those whose LOS was 1 (1.40%) or 2 days (1.67%).
After adjusting for all relevant covariables, discharge on the day of surgery increased the risk of major complications by 1.8 (95% Confidence interval [95%CI] 1.2–2.8), and minor complications by 1.6 (95%CI 1.2 – 2.2) compared to patients whose LOS was 2 days. A LOS of 1 day did not affect the risk of major complications compared to a LOS of 2 days, while a LOS of 3–4 days increased the risk of major complications by 1.4 (95%CI 1.3 – 1.6), and minor complications by 1.6 (95%CI 1.4 – 1.7).
Regarding specific complications, same-day discharge remained an independent predictor of myocardial infarction (MI), cardiac arrest, pulmonary embolism (PE), unplanned reintubation, >48 hours on ventilator, pneumonia and renal insufficiency, while a LOS of 3–4 days remained an independent predictor of MI, cardiac arrest, sepsis, acute renal failure, PE, unplanned reintubation, >48 hours on ventilator, stroke, deep vein thrombosis, pneumonia, urinary tract infection, renal insufficiency, deep and superficial surgical site infection, and wound disruption compared to patients whose LOS was 2 days (p<0.01).
Conclusion
Discharge on days 1–2 postoperatively following TKA appears to have superior outcomes compared to discharge on the day of surgery, or on days 3–4. Prospective clinical data is required to confirm the effect of discharge timing on postoperative outcomes following TKA.
