Can emergency medical services personnel identify pneumothorax on focused ultrasound examinations?

Abstract

Background Ultrasound is of proven accuracy in the diagnosis of pneumothorax. In certain locations, pre-hospital providers are adopting its use for the management of critically ill patients. Objectives To determine the sensitivity and specificity of emergency medical service (EMS) providers in identifying pneumothorax on ultrasound examinations. Methods This was an educational study evaluating 33 EMS providers. Each subject went through a brief didactic session covering the use of ultrasound in diagnosis of pneumothorax. They were then given an examination consisting of 20 individual ultrasound real-time video cases depicting either a pneumothorax or normal lung sliding. Sensitivities and specificities with 95% confidence intervals (95% CIs) were calculated for recognition of pneumothorax. Results The 33 study participants were able to identify pneumothorax with a sensitivity of 82% (95% CI 77-86%), specificity of 94% (95% CI 90-96%), positive predictive value of 93% (95% CI 89-95%), and negative predictive value of 84% (95% CI 80-87%). Conclusions Emergency medical service providers were able to identify pneumothorax at a relatively high rate. Real-time scanning by the study subjects might lead to even better results.

Acquisition and interpretation of focused diagnostic ultrasound images by ultrasound-naive advanced paramedics: trialling a PHUS education programme

“…In what appears to be the only published primary research analogous to the present study, Raio et al 11 prospectively examined 33 EMS participants using 20 video clips of lungs either positive or negative for pneumothorax, and demonstrated sensitivity and specificity of 82% (95% CI 77% to 86%) and 94% (95% CI 90% to 96%), respectively, after only 10 min of didactic training. It is surprising that the participants of Raio et al 11 achieved such a high level of specificity after so little educative input; but this could perhaps be explained by an image set that was simply less complex or consisting of more textbook appearances than that used in our trial.…”

“…It is surprising that the participants of Raio et al 11 achieved such a high level of specificity after so little educative input; but this could perhaps be explained by an image set that was simply less complex or consisting of more textbook appearances than that used in our trial. It is unlikely to be explained by a more superior calibre of paramedic clinician, as the expert physician readers with many years of practical ultrasound experience used in our trial also scored significantly lower than the paramedics in the trial of Raio et al 11. Nonetheless, it does indicate that the time required to acquire the cognitive and psychomotor skills to obtain and interpret sufficiently discriminating images is potentially much shorter than might be anticipated.…”

A Porcine Training Model for Ultrasound Diagnosis of Pneumothoraces

“…Finally, pre-hospital use of ultrasound for the detection of a pneumothorax by paramedics and the military during combat is being studied (8). Although the untrained paramedic students were only 60% accurate in their diagnostic abilities after the training session, we believe that multiple brief training sessions would increase their skills as well.…”

Research: Emergency medicine residents’ acquisition of point-of-care ultrasound knowledge and their satisfaction with the flipped classroom andragogy

“…Between four and 33 paramedics participated in the studies, possessing varying levels of training from EMT to advanced and critical care paramedics [25]. The majority of the studies utilized the absence of sonographic lung sliding (SLS) as the sole marker of pneumothorax [13,25,30,[32][33][34][35]. The highest Sn (97%) was achieved in a study by Lyon et al, which utilized a 25-minute didactic and practical training model on a cadaver [25,32].…”

“…One study conducted a follow up assessment nine months post training, demonstrating skill maintenance of 100% sensitivity and specificity [25,32]. Two studies described successful application of pleural ultrasound in the field, although no outcome data on patient care is available [32,35].…”