The feasibility of nurse practitioner-performed, telementored lung telesonography with remote physician guidance - 'a remote virtual mentor'

Abstract

Background: Point-of-care ultrasound (POC-US) use is increasingly common as equipment costs decrease and availability increases. Despite the utility of POC-US in trained hands, there are many situations wherein patients could benefit from the added safety of POC-US guidance, yet trained users are unavailable. We therefore hypothesized that currently available and economic 'off-the-shelf' technologies could facilitate remote mentoring of a nurse practitioner (NP) to assess for recurrent pneumothoraces (PTXs) after chest tube removal.

Methods: The simple remote telementored ultrasound system consisted of a handheld ultrasound machine, head-mounted video camera, microphone, and software on a laptop computer. The video output of the handheld ultrasound machine and a macroscopic view of the NP's hands were displayed to a remote trauma surgeon mentor. The mentor instructed the NP on probe position and US machine settings and provided real-time guidance and image interpretation via encrypted video conferencing software using an Internet service provider. Thirteen pleural exams after chest tube removal were conducted.

Results: Thirteen patients (26 lung fields) were examined. The remote exam was possible in all cases with good connectivity including one trans-Atlantic interpretation. Compared to the subsequent upright chest radiograph, there were 4 true-positive remotely diagnosed PTXs, 2 false-negative diagnoses, and 20 true-negative diagnoses for 66% sensitivity, 100% specificity, and 92% accuracy for remotely guided chest examination.

Conclusions: Remotely guiding a NP to perform thoracic ultrasound examinations after tube thoracostomy removal can be simply and effectively performed over encrypted commercial software using low-cost hardware. As informatics constantly improves, mentored remote examinations may further empower clinical care providers in austere settings.

Figure 1

Selected ultrasound signs utilized within the WINFOCUS algorithm for pneumothorax detection.

Figure 2

Case 1 in which the final radiology report noted a ‘tiny residual left apical pneumothorax.’ This pneumothorax was not detected after concluding the RTMUS exam.

Figure 3

Case 7: chest radiograph obtained after removal of a left-sided tube thoracostomy. The chest radiograph noted a ‘small focal lucency at the right apex that could represent a small loculated pneumothorax.’

Figure 4

Case 1: remote mentor's computer screen. The screen demonstrated the nurse practitioner's placement of the ultrasound probe and the resultant ultrasound image that depicted a color power Doppler signal from the pleural interface, suggesting the presence of lung sliding at this anatomic location. The large white arrow designated the parietal-visceral pleural interface, and the small white arrow indicated the color power Doppler signal seen at this interface.

Figure 5

Case 7: screen capture of mentor's screen in England. The screen demonstrated the image generated in Calgary suggesting a visceral-parietal pleural interface without an obvious power-slide, but a comet-tail artifact (B-line) (dashed arrow) emanating from the pleural interface.

Figure 6

Case 2: left-sided hydropneumothorax after tube thoracostomy removal with a reported maximal diameter of 15 mm. Dual arrows indicate air-fluid level of hydropneumothorax.