Pulmonary function testing in preoperative high-risk patients

Christine Eimer; Natalia Urbaniak; Astrid Dempfle; Tobias Becher; Dirk Schädler; Norbert Weiler; Inéz Frerichs

doi:10.1186/s13741-024-00368-w

Pulmonary function testing in preoperative high-risk patients

Perioper Med (Lond). 2024 Mar 5;13(1):14. doi: 10.1186/s13741-024-00368-w.

Authors

Christine Eimer^#¹, Natalia Urbaniak^#², Astrid Dempfle^{2

3}, Tobias Becher², Dirk Schädler², Norbert Weiler², Inéz Frerichs²

Affiliations

¹ University Medical Center Schleswig-Holstein, Anesthesiology and Intensive Care Medicine, Arnold-Heller Str. 3, 24105, Kiel, Germany. christine.eimer@uksh.de.
² University Medical Center Schleswig-Holstein, Anesthesiology and Intensive Care Medicine, Arnold-Heller Str. 3, 24105, Kiel, Germany.
³ Christian-Albrechts University, Institute of Medical Informatics and Statistics, Brunswikerstr. 10, 24105, Kiel, Germany.

^# Contributed equally.

Abstract

Background: Postoperative respiratory failure is the most frequent complication in postsurgical patients. The purpose of this study is to assess whether pulmonary function testing in high-risk patients during preoperative assessment detects previously unknown respiratory impairments which may influence patient outcomes.

Methods: A targeted patient screening by spirometry and the measurement of the diffusing capacity of the lung for carbon monoxide (D_LCO) was implemented in the anesthesia department of a tertiary university hospital. Patients of all surgical disciplines who were at least 75 years old or exhibited reduced exercise tolerance with the metabolic equivalent of task less than four (MET < 4) were examined. Clinical characteristics, history of lung diseases, and smoking status were also recorded. The statistical analysis entailed t-tests, one-way ANOVA, and multiple linear regression with backward elimination for group comparisons.

Results: Among 256 included patients, 230 fulfilled the test quality criteria. Eighty-one (35.2%) patients presented obstructive ventilatory disorders, out of which 65 were previously unknown. 38 of the newly diagnosed obstructive disorders were mild, 18 moderate, and 9 severe. One hundred forty-five D_LCO measurements revealed 40 (27.6%) previously unknown gas exchange impairments; 21 were mild, 17 moderate, and 2 severe. The pulmonary function parameters of forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), and D_LCO were significantly lower than the international reference values of a healthy population. Patients with a lower ASA class and no history of smoking exhibited higher FVC, FEV₁, and D_LCO values. Reduced exercise tolerance with MET < 4 was strongly associated with lower spirometry values.

Conclusions: Our screening program detected a relevant number of patients with previously unknown obstructive ventilatory disorders and impaired pulmonary gas exchange. This newly discovered sickness is associated with low metabolic equivalents and may influence perioperative outcomes. Whether optimized management of patients with previously unknown impaired lung function leads to a better outcome should be evaluated in multicenter studies.

Trial registration: German Registry of Clinical Studies (DRKS00029337), registered on: June 22nd, 2022.

Keywords: Airflow obstruction; DLCO; Intensive care medicine; Patient safety; Postoperative pulmonary complications; Postoperative respiratory failure; Preoperative screening; Pulmonary gas exchange; Spirometry; Targeted screening program.