Tele-intensivists can instruct non-physicians to acquire high-quality ultrasound images

Journal of Critical Care 30 (2015) 871–875

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Tele-intensivists can instruct non-physicians to acquire high-quality ultrasound images☆ Andrea R. Levine, MD a,⁎, Michael T. McCurdy, MD b,c, Marc T. Zubrow, MD d,e, Alfred Papali, MD b, Haney A. Mallemat, MD c, Avelino C. Verceles, MD b a

Department of Medicine, University of Maryland School of Medicine, 22 S. Greene St., Baltimore, MD, 21201, United States Division of Pulmonary and Critical Care, University of Maryland School of Medicine, 110 S. Paca St., 2nd Floor, Baltimore, MD, 21201, United States Department of Emergency Medicine, University of Maryland School of Medicine, 110 S. Paca St., 6th Floor, Baltimore, MD, 21201, United States d Program in Trauma, University of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, MD, 21201, United States e University of Maryland eCare, University of Maryland Medical System, 110 S. Paca St., Suite 5-N-162, Baltimore, MD, 21201, United States b c

a r t i c l e

i n f o

Keywords: Tele-ICU Tele-ultrasound Remote telementored ultrasound systems RTMUS Tele-intensivist

a b s t r a c t Purpose: Intensive care unit telemedicine (tele-ICU) uses audiovisual systems to remotely monitor and manage patients. Intensive care unit ultrasound can augment an otherwise limited bedside evaluation. To date, no studies have utilized tele-ICU technology to assess the quality and clinical use of real-time ultrasound images. We assessed whether tele-intensivists can instruct nonphysicians to obtain high-quality, clinically useful ultrasound images. Methods: This prospective pilot evaluated the effectiveness of a brief educational session of nonphysician “ultrasonographers” on their ability to obtain ultrasound images (right internal jugular vein, bilateral lung apices and bases, cardiac subxiphoid view, bladder) with real-time tele-intensivist guidance. All ultrasound screen images were simultaneously photographed with a 2-way camera and saved on the ultrasound machine. The teleintensivist assessed image quality, and an independent ultrasound expert rated their use in guiding clinical decisions. Results: The intensivist rated the tele-ICU camera images as high quality (70/77, 91%) and suitable for guiding clinical decisions (74/77, 96%). Only bilateral lung apices demonstrated differences in quality and clinical use. All other images were rated noninferior and clinically useful. Conclusion: Tele-intensivists can guide minimally trained nonphysicians to obtain high-quality, clinically useful ultrasound images. For most anatomic sites, tele-ICU images are of similar quality to those acquired directly by ultrasound. © 2015 Elsevier Inc. All rights reserved.

1. Introduction Although only about 30% of intensive care unit (ICU) patients receive bedside care from trained intensivists, intensivist management has consistently demonstrated improved ICU clinical outcomes [1–4]. The Leapfrog Group recommends ICU Staffing Safety Standards, which include either 24/7 in-house intensivist staffing of ICUs or off-hour rapid and reliable access to a bedside or telemedicine intensivist [5]. ICU telemedicine (tele-ICU) leverages technology to overcome geographic separation to simultaneously provide intensivist coverage for multiple remote locations, providing a potential solution to the growing shortfall of intensivists. Tele-ICU coverage may use a variety of delivery models (i.e., continuous, episodic, on-demand) to provide ICU support. As of 2013, tele-ICU monitoring and care delivery supported nearly 13% of ☆ Conflicts of Interest: None ⁎ Corresponding author at: Department of Medicine, University of Maryland School of Medicine, 22 S. Greene St., Baltimore, MD, 21201, United States. Tel.: +1 818 359 5031. E-mail addresses: [email protected] (A.R. Levine), [email protected] (M.T. McCurdy), [email protected] (M.T. Zubrow), [email protected] (A. Papali), [email protected] (H.A. Mallemat), [email protected] (A.C. Verceles). http://dx.doi.org/10.1016/j.jcrc.2015.05.030 0883-9441/© 2015 Elsevier Inc. All rights reserved.

all ICU beds in the United States [3,6] and demonstrated a significant reduction in mortality (adjusted hazard ratio of death, 0.84; 95% confidence interval [CI], 0.78-0.89; P b .001) and ICU length of stay (20% shorter; 95% CI, 19%-22%; P b .001) [6]. Tele-ICUs use sophisticated hardware and software to continuously monitor vital signs, laboratory values, radiographic studies, visualize patients and their surroundings, view ventilator parameters, and initiate therapeutic or prophylactic care [7]. Despite having access to such advanced patient data, remote monitoring precludes the physician from performing a bedside physical examination. As compared with the physical examination, however, ultrasound is arguably a more effective means of diagnosing thoracic and abdominal pathophysiology in critically ill patients. Thoracic ultrasound has been shown to more accurately diagnose pleural effusion, consolidation, alveolar interstitial syndrome, pneumothorax, and lung contusion than either auscultation or chest radiography [8,9]. In acute respiratory failure, ultrasound can facilitate real-time identification of lung pathology, with 90% accuracy when compared with either computerized tomography or plain radiography [10]. Bedside cardiac ultrasound was superior to physical examination, laboratory findings, and electrocardiograph findings for diagnosing acute decompensated heart failure [11,12]. Surgeons rely

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on ultrasound to enhance the physical examination when diagnosing patients with abdominal pain [13]. Outside of the hospital setting, the National Aeronautics and Space Administration originally designed remote telementored ultrasound (RTMUS) to help diagnose and care for astronauts aboard the space station [14,15]. Remote telementored ultrasound consists of a geographically separated expert providing real-time guidance and interpreting ultrasound images that are captured and electronically transmitted by an inexperienced ultrasonographer. With minimal training, physician and nonphysician ultrasonographers at the bedside can obtain highquality images, which are oftentimes superior to other more costly and more invasive diagnostic tests [16–18]. Further studies demonstrated that nonphysician, ultrasound-naive examiners can competently obtain clinically relevant focused assessment with sonography for trauma and extended FAST ultrasound images when guided by a tele-mentor [19–21]. To date, no studies have evaluated either the use of point-of-care bedside ultrasound performed by nonphysicians in the tele-ICU environment or the role of a tele-ICU infrastructure in constructing RTMUS systems. Furthermore, no studies have assessed the use of these images in guiding clinical diagnostic decisions. We conducted an educational feasibility pilot aimed to determine the frequency with which (1) a tele-intensivist using RTMUS principles and tele-ICU technology can instruct nonphysicians to obtain high-quality ultrasound images; (2) a tele-intensivist can interpret ultrasound images by visualizing the ultrasound screen; and (3) remotely visualized images are noninferior to images acquired directly from the ultrasound machine with regard to the ability to guide the clinical decision-making process. 2. Methods We performed an educational feasibility pilot to determine (1) the ability of nonphysicians to obtain quality images after receiving minimal ultrasound training using tele-intensivist mentored bedside ultrasound; (2) the ability of tele-intensivists to interpret the ultrasound images by visualizing the ultrasound screen; and (3) if the images captured using the tele-ICU infrastructure are comparable to those obtained from the ultrasound machine in their ability to guide point-of-care diagnosis and clinical decisions. This pilot was institutional review board– exempt and used the facilities and equipment of the University of Maryland eCare, the University of Maryland Medical System's tele-ICU. An internal medicine (IM) resident and two board-certified critical care tele-intensivists designed a standardized training module consisting of a 20-minute didactic session delivered by the IM resident to eleven nonphysician healthcare providers. Teaching used PowerPoint slides to convey elementary ultrasound principles, including appropriate ultrasound probe handling, “knobology,” and techniques for evaluating pneumothorax, pleural effusion, pericardial effusion (via four-chamber subxiphoid cardiac view), bladder, and internal jugular vein. Publicly available SonoSite eLearning videos supplemented the PowerPoint presentation to demonstrate proper ultrasonography technique. Each nonphysician learner completed an anonymous demographic form and 5-point, Likert scale [22] regarding his training (1, strongly disagree; 2, disagree; 3, neutral;, 4, agree; 5, strongly agree). We used the 5-point Likert scale because it allows a more descriptive and quantifiable means of measurement by creating an objective grading system based on one's subjective assessment. We constructed an RTMUS system using a simulated patient room with a mounted tele-ICU camera to visualize both the ultrasound machine and the ultrasonographer. Images were captured using a Sony camera with a 340° pan, 120° tilt, 18 × optical, 12 × digital, and 380k pixel and transmitted to an intensivist monitoring the patient room from a remote site using Philips VISICU monitoring software. We acquired ultrasound images with a SonoSite SICU model ultrasound (SonoSite Inc, Bothell, Washington). Various nonphysician medical providers volunteered as “ultrasonographers” and acquired images on a volunteer “patient.” The patient

was a 30-year-old healthy male with a body mass index of 25. A single tele-intensivist with ultrasound training and experience in the ICU and who routinely works at the University of Maryland eCare was tele-consulted. The tele-intensivist logged into the tele-ICU system and confirmed visualization of the patient, the ultrasonographer's hand, and the ultrasound screen by the tele-ICU camera. The teleintensivist verbally instructed the ultrasonographer to obtain the following images: (1) right internal jugular vein; (2) bilateral lung apices to assess lung sliding; (3) bilateral axillary lower lung fields to assess pleural effusion; (4) heart (four-chamber subxiphoid view); and (5) bladder. When the tele-intensivist felt the ultrasound image sufficed, he focused the camera on the ultrasound machine to capture an ultrasound screenshot; the time to image acquisition was recorded, and the screenshot was labeled with a unique numeric code. The same image was simultaneously saved directly from the ultrasound machine and labeled with the above-mentioned code. The tele-intensivist completed an ultrasound checklist at the time of image acquisition to indicate whether each anatomical site was adequately visualized. Furthermore, the tele-intensivist mentor completed an anonymous demographic form regarding his ultrasound experience and two additional 5-point Likert scales [22] (1, strongly disagree; 2, disagree; 3, neutral; 4, agree; 5, strongly agree) to evaluate the images' quality and clinical use (ie, whether a clinical decision could be made on the basis of the images). The tele-intensivist mentors also compared the images acquired directly from the ultrasound to those acquired using the RTMUS. A physician board-certified in emergency medicine, IM, and critical care medicine, who was not involved in image acquisition or mentorship, later compared the images acquired directly from the ultrasound machine to those acquired using the Phillips VISICU tele-ICU technology (Fig. 1). Images captured using the tele-ICU technology were compared side by side to the images captured directly on the ultrasound machine. The independent physician was asked to focus specifically on the clinical use of the images. The physician was informed of the probe location and asked to determine his level of confidence with which the following statements could be made for both the images captured on the ultrasound and the images captured with the tele-ICU camera software: (1) the carotid artery and the internal jugular vein could be differentiated, (2) a pneumothorax could be excluded (bilaterally), (3) a clinically significant pleural effusion could be excluded (bilaterally), (4) a clinically significant pericardial effusion could be excluded, and (5) the urinary bladder could be identified. Evaluation of the images was performed using a 5-point Likert scale [22] (1, strongly disagree; 2, disagree; 3, neutral; 4, agree; 5, strongly agree). 3. Results Eleven nonphysician medical providers volunteered for the educational pilot based on word-of-mouth advertising in our hospital's medical ICU (MICU) and cardiac ICU. Each of the volunteers attended a mandatory training session, during which time they provided their demographic information (Table 1) and completed a Likert scale–based evaluation regarding the training experience. We reported data from the “nonphysician training experience” Likert scale as mean ± SD (Table 2). All data are reported as mean ± SD for continuous variables or counts and percentages for proportions. One physician with nine years of experience obtaining ultrasound images in the ICU and emergency department, interpreting selfacquired images and overreading ultrasound images acquired by residents and fellows, and five years of tele-ICU experience, acted as the tele-mentor. He completed a checklist indicating whether images were adequately visualized at each anatomic site, a Likert scale regarding the ease of his experience collecting images using the RTMUS system, and a Likert scale regarding the quality and clinical use of the images collected. Seventy-seven images were acquired according to the standardized checklist. The time to adequate image acquisition was measured in seconds and reported as a mean ± SD (Table 3). The

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Fig. 1. Top row: Images acquired directly from ultrasound machine. (Left to right) Internal jugular, right upper lobe, left upper lobe, right lung base, left lung base, subxiphoid, and bladder. Bottom row: Images acquired from tele-ICU camera technology. (Left to right) Internal jugular, right upper lobe, left upper lobe, right lung base, left lung base, subxiphoid, and bladder.

physician agreed (further defined as “agree” or “strongly agree” on the 5-point Likert scale) that he could visualize all images acquired at each anatomical location. The quality and clinical use of each image were interpreted using a 5-point Likert scale. The mentor teleintensivist agreed that 70 (91%) of the 77 of the images obtained via the tele-ICU camera were high quality. The quality of images discriminated by anatomic site is reported in Table 3. A second analysis of these results as interval data was performed on all images obtained. High-quality images were defined as those rated 4 or 5, and lower quality images were defined as those rated 3 or below. Comparison of images across all anatomical sites showed no significant difference (χ 2 test, P = .58), confirming uniform image quality. The tele-intensivist noted no difference in quality between images saved directly from the ultrasound and those acquired with the tele-ICU camera. The teleintensivist felt comfortable making clinical decisions based on the images acquired via RTMUS technology 74 (96%) of 77 of the time. The clinical use of the images, as determined by the tele-intensivist mentor, based on anatomical site is represented in Table 3. One physician board-certified in emergency medicine, IM, and critical care medicine, with 10 years of experience performing and interpreting ultrasound and greater than 20 hours per week of bedside ultrasound use, image interpretation, and overreading of residentacquired ultrasound images reevaluated the clinical use of all of the images. The physician was informed of the ultrasound probe position and was asked to evaluate both the Philips tele-ICU images and the Table 1 Demographic characteristics of nonphysician ultrasonographers (N = 11) Ultrasonographer

No. (%)

Female Training level Registered nurse training Bachelor of science in nursing training Nursing student Respiratory therapist training Other training Employment location ICU Step down unit Trauma ICU Critical Care Registered Nurse Certification Previous Experience with US Years of previous US experiencea Years of previous nursing experience

10 (91) 2 (18) 5 (45) 2 (18) 1 (9) 1 (9) 9 (82) 1 (9) 1 (9) 5 (45) 3 (27) 0.6 ± 1.5 6.7 ± 7.7

a Nonphysician US experience further detailed as US use for placement of central venous access or peripheral IV insertion.

ultrasound images for the ability to make clinical decisions. Quality of the tele-ultrasound images differed significantly (P b .001) from the quality of the images acquired from the ultrasound machine in only two anatomic locations—the right upper lung and left upper lung. We also used Fisher exact test to compare the third-party observer's rating of image quality when obtained from the ultrasound directly versus using the Phillips software. The sites visualized demonstrated no difference in quality between modality used (IJ, RUL, Sx and BL, P = 1.0). Only two sites demonstrated a significant difference when rated by our third party (RLL, P = .035, and LLL, P = .024). For all other anatomical sites, the images obtained using the tele-ICU camera were not clinically inferior to those obtained directly from the ultrasound. Clinical use and comparison data, as determined by the independent interpreter, are presented in Table 4. Comparison images are displayed in Fig. 1. 4. Discussion Tele-ICU allows patients in hospitals without intensivist coverage to receive intensivist-driven care. However, one shortcoming of remotely located intensivists is the inability to perform hands-on physical examination or bedside diagnostic studies. Ultrasonography, which can provide meaningful diagnostic information that may supplant the need for a physical examination in certain conditions, is a reliable diagnostic tool that even minimally trained clinicians can effectively use [8–13,16–20,23]. We confirmed that novice, nonphysician ultrasonographers can successfully acquire clinically useful, high-quality diagnostic images guided by geographically removed mentors with a brief 20minute training session. This pilot demonstrates that the images acquired using a RTMUS system with minimally trained nonphysicians can be high quality and useful in making clinical decisions. When compared with images obtained at the bedside with the ultrasound, the images obtained remotely are of similar clinical use. The lung apices were the only anatomical sites that yielded clinically inferior images. Lung sliding, visualized at the Table 2 Nonphysician ultrasound training experience Question

Likert scorea

SD

Prepared to perform ultrasound given training received Ultrasound experience considered positive Comfortable using ultrasound prior to training Comfortable using ultrasound after training

4.5 5.0 2.6 4.8

0.5 0.0 1.3 0.4

a Likert score of 1 (strongly disagree), 2 (disagree), 3 (neutral), 4 (agree), 5 (strongly agree).

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Table 3 Acquisition time, quality, and clinical use of ultrasound images as assessed by tele-intensivist Anatomic site

Mean time to image acquisition (seconds)

High-quality images

Right internal jugular vein (n = 11) Right lung apex (n = 11) Left lung apex (n = 11) Right lung base (n = 11) Left lung base (n = 11) Subxiphoid (n = 11) Bladder (n = 11)

28.7 ± 25.8 30.8 ± 17.0 33.9 ± 15.0 75.6 ± 36.7 43.1 ± 23.1 100.2 ± 77.1 34.9 ± 48.2

4.3 ± 0.4 4.7 ± 0.5 4.8 ± 0 .4 4.0 ± 0.8 4.2 ± 0.8 4.3 ± 0.8 5.0 ± 0

a

% response

Comfortable making clinical decisionsa

% response

Snapshot differs from images on US machinea

% response

100 100 100 73 82 82 100

4.8 ± 0.4 4.8 ± 0.4 4.6 ± 0.5 4.0 ± 0.9 4.1 ± 0.5 4.4 ± 0.5 4.8 ± 0.4

100 100 100 81 91 100 100

1.2 ± 0.4 1.0 ± 0 1.1 ± 0.3 1.5 ± 0.7 1.5 ± 0.5 1.6 ± 0.9 1.2 ± 0.4

100 100 100 91 100 91 100

Time to acquisition expressed in mean ± SD. a Likert score of 1 (strongly disagree), 2 (disagree), 3 (neutral), 4 (agree), 5 (strongly agree).

lung apex, is best identified in a dynamic or live mode of visualization. Although the tele-intensivist mentor visualized the dynamic image in real-time and evaluated the image as clinically useful, the ultrasound expert's secondary evaluation was done retrospectively, viewing only a static image. The discrepancy between the two interpreters highlights the importance of clinical decision making to be performed at the time of image acquisition. In cases where a real-time assessment is not feasible, a static image captured in Motion Mode [24,25] or with Doppler [25] may demonstrate lung sliding, although this was not evaluated in our pilot. Remote telementored ultrasound fits well within the established tele-ICU infrastructure to permit physicians, with the help of minimally trained bedside nurses, technicians, or respiratory therapists, to obtain real-time, point-of-care, high-quality, ultrasound images that can directly guide patient care. A “hub and spoke” model uses a centralized tele-ICU as a base from which critical care services originate. Staffing at the hub includes intensivists, nurses, and technical staff who are remotely connected to numerous medical facilities (spokes) [7]. Using this model, geographically removed physicians can provide ultrasound expertise to many patients who may otherwise have limited exposure to skilled ultrasonographers and interpreters or who may be too medically unstable to travel to more advanced imaging and await radiological interpretation. Furthermore, incorporating an RTMUS system into the tele-ICU infrastructure can help overcome the inability to perform physical examination or bedside diagnostic studies that make some physicians skeptical of tele-ICU. Our data were collected using the high-fidelity technology currently used in both the tele-ICU continuous care and episodic care models. Regardless of the model used, the tele-ICU infrastructure uses high-quality audiovisual packages that allow enhanced evaluation of the actual patient, monitoring of vital signs, evaluation of trends, and two-way communication between physician and bedside staff. The camera software enables high-resolution visualization of the patient, the “ultrasonographer,” and the ultrasound screen, making the tele-ICU infrastructure ideal for a RTMUS. Increasing data supports the use of commercially available software to establish effective and accurate RTMUS systems [19,21,26,27]. Despite an inability to provide continuous monitoring, tele-ICU packages using laptop computers and handheld personal desktop assistants

could guide image acquisition and transmit images to remote experts. Although not used in our pilot study, such systems would permit asneeded, real-time interpretation and guidance for rapid performance of diagnostic tests and facilitate accurate and clinical decision making. To date, no data have assessed the effect on medical decision making using images acquired from an RTMUS system designed using commercially available software to the images acquired from an RTMUS system operating state-of-the-art, widely adopted tele-ICU software. This pilot study has limitations. Its small sample size of only 11 nonphysician participants makes it underpowered and results in a high potential for a type II statistical error. Perhaps with a larger sample size, a difference in image quality and clinical use would be apparent between the ultrasound and the tele-ICU images. Furthermore, only one teleintensivist mentor with considerable bedside and tele-ICU experience participated in the pilot, which may limit the generalizability of the pilot to all tele-ICU programs. Despite diagnostic ultrasound training now being required in critical care fellowships, these skills are not yet ubiquitous among practicing intensivists; therefore, the degree of ultrasound experience and training of other tele-intensivists may not correlate to that of the physician participating in our pilot. However, we propose that mentors in any RTMUS system should demonstrate significant ultrasound training and experience before guiding such remote image acquisition. The participants in this pilot were primarily nurses from the University of Maryland MICU, a unit with significant bedside ultrasound usage. Although only three nurses reported previous ultrasound experience, most of the MICU nurses have significant exposure to ultrasonography through observation and interaction with the medical team. This may have resulted in a slightly higher level of comfort with ultrasonography when compared with nurses with minimal previous exposure to bedside ultrasound, making the results of the pilot less generalizable. Finally, the patient used to perform this pilot was a healthy male patient with a body mass index of 25, obviously not intubated or sedated. Attempting bedside ultrasonography on a cooperative, spontaneously breathing person with a normal body habitus likely resulted in easier and higher quality image acquisition, again limiting the generalizability to all ICU patients. Our pilot data are encouraging. Future studies should explore the ability of remote tele-mentored nonphysicians to acquire ultrasound

Table 4 Comparison of image clinical use Anatomic site

Right internal jugular vein (n = 11) Right lung apex (n = 11) Left lung apex(n = 11) Right lung base (n = 11) Left lung base(n = 11) Subxiphoid (n = 11) Bladder (n = 11) a b

Able to make clinical decisions based on Tele-ICU snapshots—tele-intensivest mentora

Able to make clinical decisions based on Tele-ICU snapshots—third party interpreter (A)

4.9 ± 0.3 4.8 ± 0.4 4.8 ± 0.4 4.0 ± 0.8 4.4 ± 0.5 4.5 ± 0.5 4.9 ± 0.3

4.3 ± 0.7 3.8 ± 0.6 3.8 ± 0.4 2.0 ± 0.8 2.5 ± 0.9 3.7 ± 0.9 4.4 ± 0.5

Likert score of 1 (strongly disagree), 2 (disagree), 3 (neutral), 4 (agree), 5 (strongly agree). P value obtained comparing mean quality scores using Student t test.

a

Able to make clinical decisions based on ultrasound images—third party interpreter (B) a

P (A vs B)b

4.6 ± 0.7 5.0 ± 0 4.9 ± 0.3 2.7 ± 1.3 3.5 ± 1.7 3.6 ± 1.6 4.8 ± 0.6

.2 .001 .001 .12 .1 .8 .07

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