To explore the factors related to new pulmonary infection after proximal femoral nail antirotation (PFNA) internal fixation in the elderly patients with femoral intertrochanteric fractures.

From January 2017 to December 2019, a total of 110 elderly patients (age≥80), who underwent PFNA internal fixation for femoral intertrochanteric fracture in Guangzhou Red Cross Hospital, were reviewed retrospectively, including 30 males and 80 females with an average age of (85.62±4.41) years. The incidence of the pulmonary infection within seven days after PFNA internal fixation was recorded and the factors such as age, gender, preoperative preparation time, length of hospital stay, anesthesia method, American Society of Anesthesiologists (ASA) grade, smoking history, preoperative anemia, types and number of preoperative underlying diseases, operation time, the timing of postoperative mobilization, body mass index (BMI), and whether the central vein catheter was placed were analyzed by the multivariate logistic regression.

Clinical symptoms and imaging evaluation confirmed that 29 of the 110 cases developed a pulmonary infection within seven days after PFNA internal fixation. The factors which included preoperative preparation time(χ²=22.808), anesthesia method(χ²=7.992), American Society of Anesthesiologists (ASA) grade(χ²=6.709), smoking history(χ²=15.812), pulmonary diseases(χ²=17.241), history of stroke(χ²=20.801), number of preoperative basic diseases(χ²=23.508), the timing of postoperative mobilization (χ²=7.677)and whether the central vein catheter was placed (χ²=5.810)were related to the pulmonary infection within seven days after PFNA internal fixation (all P<0.05), while the gender, preoperative anemia, cardiovascular underlying disease, renal disease, history of diabetes, operation time, body mass index (BMI) showed no relationship with it(P>0.05). Multi-variation analysis confirmed that the factors including preoperative preparation time[odds ratio(OR)=19.183], anesthesia method(OR=20.829), smoking history(OR=8.760), pulmonary diseases(OR=9.837), history of stroke (OR=8.698), the timing of postoperative mobilization (OR=13.423)and number of preoperative basic diseases (OR=2.610)were independent factors (all P<0.05).

The factors which included preoperative preparation time, anesthesia method, smoking history, pulmonary diseases, history of stroke, the timing of postoperative mobilization and number of preoperative underlying diseases are confirmed as the relevant risk factors for the pulmonary infection within seven days after PFNA internal fixation.