Partial pressure of oxygen level at admission as a predictor of postoperative pneumonia after hip fracture surgery in a geriatric population: a retrospective cohort study

Abstract

ObjectiveTo identify whether the partial pressure of oxygen in arterial blood (PaO2) level at admission is an independent risk factor as a prognostic biomarker to predict postoperative pneumonia (POP) in the geriatric population who have undergone hip fracture surgical repair at our hospital.DesignA retrospective cohort study.SettingThis is a retrospective chart review of POP after hip fracture surgery in China.ParticipantsIn training cohort, patients aged ≥65 years who had hip fracture surgery between 1 January 2018 and 30 November 2019. In the validation cohort, a series of patients who underwent hip fracture surgery between 1 January 2020 and 28 February 2020.InterventionsReceiver operating characteristic (ROC) analysis was used to obtain the area under the ROC curve (AUC) and cut-off values of PaO2 to predict POP. A binomial logistic regression model was used to identify potential risk factors for POP by analysing demographic distribution factors, laboratory results, preoperative comorbidities and surgical factors. Then the regression model was validated using an independent cohort.ResultsIn the training cohort, ROC curves were generated to compare the predictive performance of PaO2 for the occurrence of POP, and the area under the receiver operating characteristic curve (AUC) was 0.653 (95% CI 0.577 to 0.729, p<0.0001), with sensitivity and specificity values of 60.0% and 63.8%, respectively. The cut-off value of the PaO2 for POP was 72.5 mm Hg. Binary logistic regression analysis revealed that hypoxaemia (PaO2 <72.5 mm Hg) at hospital admission (OR=3.000, 95% CI 1.629 to 5.528; p<0.0001) was independent risk factors associated with POP after hip fracture surgery. In the validation cohort, PaO2 had a predictive effect for POP (AUC 0.71, 95% CI 0.541 to 0.891).ConclusionsThe current study revealed that the PaO2 level at hospital admission is a simple and widely available biomarker predictor of POP after hip fracture surgery in elderly patients.

What are Risk Factors of Postoperative Pneumonia in Geriatric Individuals after Hip Fracture Surgery: A Systematic Review and Meta‐Analysis

“…2h). However, after sensitivity analysis by eliminating two studies with sample sizes <1000, 9,12 the I 2 value for the five other studies 4–8 decreased to 48%, and the significance remained unchanged ( OR = 2.19, 95% CI : 1.75–2.74, P < 0.0001), indicating the reliability of the result (Fig. S1e).…”

“…2b). However, the I 2 value for five HQ studies 5,7,9,11,13 decreased to 0%, and the significance remained unchanged (OR = 1.66, 95% CI: 1.30-2.13, P < 0.0001), indicating the reliability of the result was (Fig. S1b).…”

“…Seven of the 10 included studies were conducted in China. In nine of the 10 studies, [4][5][6][8][9][10][11][12][13] the average or median age of the participants was >70 years. In the one other study, the patient distribution across different age groups were reported rather than the average age; however, age >65 years was one of the inclusion criteria.…”

“…Early surgery is recommended for such patients 2 . Postoperative pneumonia (POP) is the commonest postoperative complication, with an incidence of 3.5%–15.2%, ranking second to delirium 3–13 . Negative outcomes associated with POP included prolonged hospital length of stay, more frequent intensive care unit (ICU) stays, and a higher rate of sepsis, readmission, and mortality 14–16 .…”

Risk factors for postoperative pneumonia in patients undergoing hip fracture surgery: a systematic review and meta-analysis

“…After eliminating 286 duplicates and 918 ineligible articles based on titles and abstracts, the full text of 101 articles were reviewed. After excluding 91 articles without information of inclusion criteria, 10 articles [ 7 – 14 , 18 , 19 ] were finally selected for the meta-analysis.…”