Precision of pleural puncture sites using thoracic ultrasound

Introduction: Lung ultrasound (LUS) has been recommended by the British Thoracic Society as a standard of care before performing pleural procedures since 2010. Indeed, the choice of the puncture site based only on physical examination and chest x-ray can lead to complications. The aim of this study was to compare the accuracy of pleural puncture sites using LUS as opposed to clinical examination. Methods: An evaluative prospective study including 43 patients hospitalized in the pneumology department at the Military Hospital of Tunis was conducted between January and November 2021.Pleural puncture sites were proposed by two groups involving ‘senior’ and ‘junior’ physicians, classified according to their experience and grades, based on the clinical examination and the chest x-ray findings. The accuracy of the proposed sites was then verified by an ultrasound-qualified “expert” using LUS. Results: The mean age was 60 ± 17 years. LUS revealed the presence of pleural effusion in 88% of the cases (n=38). Differential diagnosis was therefore excluded in 12% of the cases (n=5), including pleural thickening (5%, n=2) and atelectasis (7%, n=3). Compared to LUS, clinical examination and chest x-ray had lower sensitivities, estimated at 74% and 83%, respectively. The clinical identification error rate was significantly higher in junior (77%) compared to senior physicians (49%) (p<0.05). LUS prevented possible accidental organ puncture in 36% of the cases (n=31). The risk factors associated with inaccurate clinical site selection included right-sided effusion and minimal pleural effusion on chest radiography, with an estimated relative risk (RR) of 1.44 [CI95%:0.56-3.72] and 1.82 [CI95%:0.52-6.40], respectively. The experience of the senior physicians influenced the choice of the clinical sites with moderate agreement (Kappa index: 0.4-0.6). Conclusion: LUS significantly improves the accuracy of pleural puncture sites, thus minimizing the risk of complications regardless of the operator’s level of clinical experience.