[Timing of sequential noninvasive mechanical ventilation following early extubation in aged patients with severe community-acquired pneumonia].

OBJECTIVE

To explore the timing of sequential noninvasive positive pressure ventilation (NIPPV) following endotracheal intubation mechanical ventilation (ETI-MV) in aged patients with severe community-acquired pneumonia (SCAP).

METHODS

A prospective cohort study was conducted. The SCAP patients aged ≥ 75 years old admitted to respiratory intensive care unit (RICU) of the First Affiliated Hospital of Xinjiang Medical University from July 2017 to August 2019 were enrolled. SCAP was diagnosed according to the criteria of Guidelines for the diagnosis and treatment of community-acquired pneumonia in adults in China (2016) published by Chinese Thoracic Society. ETI-MV was initially performed as respiratory support after RICU admission. Sequential NIPPV was performed immediately following extubation when the patients exhibited pulmonary infection abated (PIA) window. The gender, age, underlying diseases, and body temperature, heart rate (HR), respiratory rate (RR), oxygenation index (PaO/FiO) after RICU admission, as well as acute physiology and chronic health evaluation II (APACHE II) score, improved pneumonia score of British Thoracic Society (confusion, uremia, respiratory, blood pressure, age 65 years, CURB-65), and pneumonia severity index (PSI) score within 24 hours after RICU admission were recorded. The duration and times of ETI, the incidences of ventilator associated pneumonia (VAP) and aspiration, the duration of mechanical ventilation (MV), the length of RICU and hospital stay and RICU prognosis were also recorded. The patients were divided into the ETI ≤ 7 days group and the ETI > 7 days group according to the duration of ETI, and the clinical data were compared between the two groups. Multivariate Logistic regression analysis was used to screen the risk factors of aged patients with SCAP whose ETI was more than 7 days, and receiver operator characteristic (ROC) curve was drawn to evaluate the predictive value of risk factors.

RESULTS

Fifty aged patients with SCAP were enrolled, with 24 patients in the ETI ≤ 7 days group and 26 in the ETI > 7 days group. Univariate analysis showed that compared with the patients with ETI ≤ 7 days, the incidences of concurrent cerebrovascular diseases [46.2% (12/26) vs. 16.7% (4/24)], VAP [61.5% (16/26) vs. 16.7% (4/24)] and aspiration [69.2% (18/26) vs. 25.0% (6/24)] were significantly increased in patients with ETI > 7 days (all P < 0.05). Multivariate Logistic regression analysis indicated that VAP and aspiration were independent risk factors of ETI > 7 days in the aged SCAP patients [VAP: odds ratio (OR) = 4.852, 95% confidence interval (95%CI) was 1.076-21.877, P = 0.040; aspiration: OR = 5.903, 95%CI was 1.474-23.635, P = 0.012]. ROC curve analysis showed that the area under ROC curve (AUC) of VAP for predicting ETI > 7 days in aged patients with SCAP was 0.724, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and Youden index were 61.54%, 83.33%, 80.00%, 66.67%, 3.69, 0.46 and 0.45, respectively. Similarly, the AUC of aspiration was 0.721, the sensitivity, specificity, PPV, NPV, PLR, NLR and Youden index were 69.23%, 75.00%, 75.00%, 69.23%, 2.77, 0.41 and 0.44, respectively. Analysis of prognostic indicators showed that compared with patients with ETI ≤ 7 days, the reintubation rate and RICU mortality were significantly increased in patients with ETI > 7 days [53.8% (14/26) vs. 4.2% (1/24), 38.5% (10/26) vs. 12.5% (3/24), both P < 0.05]. Moreover, the patients with ETI > 7 days had significantly prolonged total duration of MV, the length of RICU stay and total hospital stay as compared with the patients with ETI ≤ 7 days [total duration of MV (days): 23.8±11.8 vs. 11.3±3.1, length of RICU stay (days): 30.6±14.1 vs. 16.0±5.1, total length of hospital stay (days): 33.0±14.9 vs. 20.2±6.1, all P < 0.01].

CONCLUSIONS

Sequential NIPPV performed immediately following extubation within 7 days in the aged SCAP patients might reduce the mortality and shorten the duration of MV. The prolonged ETI duration because of the VAP or aspiration would lead to a reduced function of sequential NIPPV and an increased mortality of the aged patients with SCAP.