Clinical examination does not reliably determine safe site for Thoracentesis

Abstract

Introduction: Several well-recognized adverse complications are associated with 'blind' procedures (i.e. based on clinical examination and CXR) including mortality related to drain misplacement. Aim: To determine the accuracy of clinical examination in selecting safe sites for thoracentesis in a busy thoracic ward. Methods: The study was performed prospectively on inpatients admitted to a tertiary teaching hospital with pleural effusion. For each patient, up to five clinicians of varying levels of experience were asked to determine a safe site for thoracentesis. Clinician experience was defined based on the number of procedures performed within the last 12 months (level 1 least experienced; level 4 most experienced). After viewing the radiology, each clinician examined the patient (blinded to the previous examiner) and identified a safe site for pleural drainage. A small group of trained physicians, who had successfully completed an accredited thoracic ultrasound course, immediately examined the selected site with ultrasound to determine its safety based on the predefined criterion of the presence of fluid >1 cm perpendicular to the chosen site. Result: A total of 59 examinations were performed on 19 patients. 50 sites were selected based on clinical examination as being safe for thoracentesis. In 9 examinations, no site was identified as being safe. Among the selected sites, 15 errors (30%) were noted. These were identified on ultrasound as reflecting underlying spleen (n = 5), fluid <1 cm(n = 5), liver (n = 4) or diaphragm (n = 1). Clinical errors were made by physicians of all levels of experience (40% level 1, 27% level 2, 17% level 3 and 29% level 4) (p > 0.7 for comparison of error rates according to experience). Effusion size did not influence the safety of site selection. Conclusion: A significant number of clinical errors are made by clinicians using clinical examination alone regardless of the clinical experience or the magnitude of pleural effusion.