Utility of Point of Care Ultrasound in Humanitarian Assistance Missions

ABSTRACT

Introduction

Point of care ultrasound (POCUS) is increasingly used in primary care in the USA and has been shown to provide significant benefit to care in deployed military settings and during disaster relief efforts. It is less studied as a tool during humanitarian assistance missions. We sought to determine the utility of POCUS in a humanitarian assistance setting during the February 2019 joint U.S.–Brazilian hospital assistance mission aboard the Hospitalar Assistance Ship Carlos Chagas along the Madeira River in the Brazilian Amazon.

Materials and Methods

Point of care ultrasound was offered as a diagnostic modality to primary care physicians during the course of a month-long mission. A handheld IVIZ ultrasound machine was loaned for use during this mission by Sonosite. A P21v phased array (5-1 MHz) or an L38v linear (10-5 MHz) transducer was used for scanning. Requests for POCUS examinations, their findings, and changes in patient management were recorded.

Results

Point of care ultrasound examinations were requested and performed in 24 of 814 (3%) outpatient primary care visits. Ten of these studies (42% of POCUS examinations, 1.2% of all patient visits) directed patient management decisions, in each case preventing unnecessary referral.

Conclusions

In this austere setting, POCUS proved to be an inexpensive, effective tool at preventing unnecessary referrals. Future medical humanitarian assistance missions may likewise find POCUS to be a primary care force-multiplier.

INTRODUCTION

Point of care ultrasound (POCUS) is increasingly used in primary care in the USA^1,2 and has been shown to provide significant benefit to care in deployed military settings and during disaster relief efforts.^3–9 It is less studied as a tool during humanitarian assistance missions.^10–16 However, given handheld ultrasound devices’ decreasing cost, high resolution, and versatility, POCUS provides an ideal imaging modality for austere medical environments. In fact, handheld ultrasound may be the only feasible imaging modality in austere environments that lack infrastructure capable of supporting X-ray, computed tomography, or magnetic resonance imaging machines.

The Brazilian Navy provides primary medical and dental care to nonindigenous populations living along the rivers in the Brazilian Amazon through biannual (twice per year) hospital assistance missions conducted by four hospital ships.^17,18 These populations arose from the diaspora out of the central Brazilian Amazon after the rubber industry collapsed. They are citizens of Brazil, speak a dialect of Brazilian Portuguese, and are entitled to Brazil’s free healthcare system. The communities are often semi-nomadic; moving when their homes are irreparably damaged in flooding or when local natural resources diminish below viability. Community members may occasionally take seasonal jobs in larger cities; larger villages have some electricity. Many of the communities are several days’ journey by boat to a major metropolitan area. Their remoteness limits access to this healthcare, so the Brazilian government provides it through a joint effort between the Ministry of Health and Navy.^18,19 Although they sometimes stop at communities of several thousand inhabitants, their focus is to provide care to smaller communities (with populations under 500) with no access to medical facilities. This coordinated effort has been ongoing for 45 years. As part of the Brazilian Navy’s effort to build international collaboration, they occasionally invite foreign military medical personnel to participate in these humanitarian missions.^17,18,20

The February 2019 Madeira River hospital assistance mission was a joint mission conducted by the Brazilian ninth Naval District and U.S. Navy’s 4th Fleet, providing primary care to nonindigenous populations along the Madeira River on the Carlos Chagas Hospitalar Assistance Ship. These joint missions are designed to improve interoperability of our Navies, and more broadly improve relations between Brazil and the USA. This was the first mission of this kind with portable POCUS available as a diagnostic tool. The primary objective of this study was to quantify the extent to which POCUS was utilized and the extent to which POCUS informed patient management decisions on this mission to give insight into whether POCUS should be included in all military medical humanitarian missions as part of their standard capability. The secondary objective was to estimate the cost savings, if any, yielded by POCUS evaluation.

METHODS

Study Oversight and Design

This is a retrospective, observational analysis of POCUS utilization and impact during the February 2019 Brazilian Riverine mission and was approved by the Naval Medical Center Portsmouth Institutional Review Board.

Subjects and Materials

The February 2019 Madeira River hospital assistance mission provided care to eight communities along the Madeira River (Fig. 1). Detailed patient descriptions and diagnoses for all patients are described elsewhere.²⁰ Subjects were patients seen for outpatient care who were referred for POCUS evaluation. Any care provider could request a POCUS evaluation. Providers included Brazilian general surgeons, obstetricians, intern-trained general medical officers, and family physicians, all with limited ultrasound experience, none of whom were credentialed to use handheld ultrasound. U.S. providers were a pediatrician, dermatologist, family medicine resident, and family medicine physician. The family medicine physician was credentialed to use POCUS. Ultrasound was directly supervised by the credentialed family medicine physician, with remote supervision by a dual family medicine/emergency physician also credentialed in POCUS. Supervised POCUS was performed by the U.S. family medicine resident and staff family medicine physician, and each of the Brazilian providers. SonoSite loaned a portable IVIZ ultrasound for use during this mission, allowing POCUS evaluation for a focused assessment with sonography for trauma (FAST/limited abdominal), obstetric (OB), pelvic non-OB, and soft tissue pathology. All ultrasound scans were performed with a handheld IVIZ ultrasound machine using a C60v curvilinear (5-2 MHz) or L38v linear (10-5 MHz) transducer. All scans were conducted as part of routine clinical work (Fig. 2). Scans are automatically recorded within the device, and were also stored as .pdf files for remote review and documentation on an encrypted laptop. Patient data were collected in the Brazilian electronic health tracking system (a program similar to an Excel spreadsheet), which is uploaded from the mission computer to the Ministry of Health system after each mission.

FIGURE 1.

Madeira River mission stops.

FIGURE 2.

Lt. John Sullivan, U.S. Navy, [left] instructs 1st Lt. Livia Laura, Marinha do Brasil [center] on handheld ultrasound use to confirm viable intrauterine pregnancy while Brazilian Navy Cmdr. Carlos Marsico [right] observes.

Cost estimates were based on average costs, durability, and utilization of products, all converted to U.S. dollars.

Protocol

After IRB approval, a de-identified dataset for all visits was generated from the Brazilian electronic health tracking system.

Outcomes

Outcomes tracked were number of patients referred, indication for referral, results of the ultrasound examination, and whether those results changed management. Cost outcomes were the average cost per evacuation of POCUS (POCUS prorated across evacuations prevented) and evacuations by boat or helicopter.

Statistical Analysis

Descriptive statistics were generated using a Texas Instruments TI-84 Plus graphing calculator.

RESULTS

Twenty-four of 814 patients who presented for outpatient medical care were referred for POCUS evaluation. The indications, findings, and management decisions for these are listed in Table I. The mean age of patients was 24, with 88% females and 12% males. Of the females 52% (n = 21) were pregnant. Fifty-eight percent (n = 14) of the examinations were pelvic OB evaluations; 12.5% (n = 3) non-OB pelvic examinations; 16% (n = 4) FAST/Abdominal examinations; 8% (n = 2) soft tissue; and 4% (n = 1) musculoskeletal examinations. Of the 24 patients who underwent POCUS evaluation, 42% (n = 10) had clinical symptoms that, without POCUS, would have been recommended for evacuation. In each of these cases, POCUS provided a diagnosis (i.e., viable intrauterine pregnancy as an explanation of amenorrhea) or demonstrated an absence of concerning pathology (i.e., absence of cholecystitis) that prevented evacuation.

TABLE I.

Type, Indications, Findings, and Management Change of In-field POCUS Examinations

Type	Indication	Findings	Change management
ABD	RUQ paina	No FF or liver/GB pathology	N
ABD	RUQ pain	No FF or liver/GB pathology	N
ABD	RLQ pain	No appendicitis or FF visualized	N
Biliary	Positive Murphy’s sign	No cholecystitis or dilated CBD, no FF or liver pathology	Y
Pelvic Non-OB	SAB	No retained POC	Y
Pelvic Non-OB	History of ovarian cyst	Stable, < 4cm, no FF	Y
Pelvic Non-OB	History of ovarian cyst	No cysts or FF	Y
MSK	Right hip pain	No effusion or cystic lesions	N
OB	38 wga, planned RCS	Viable IUP, breech	N
OB	2 mo amenorrhea	No IUP	N
OB	4 mo amenorrhea	Viable IUP, + HCG 2hr later	N
OB	3 mo amenorrhea	Viable IUP, no HCG available	Y
OB	16 wga	Viable IUP	N
OB	20 wga	Viable IUP	N
OB	36 wga (was breech at 32 wga)	Viable IUP, VTX presentation	Y
OB	32 wga	Viable IUP	N
OB	17 wga	Viable IUP	N
OB	3 mo amenorrhea	Viable IUP (+HCG 2 hours later)	N
OB	2 mo amenorrhea	No IUP, no HCG available	Y
OB	24 wga	Viable IUP	N
OB	30 wga	Viable IUP	N
OB	2 mo amenorrhea	No IUP, no HCG available	Y
Soft tissue	Ganglion cyst	Small, not appropriate for drainage	Y
Soft tissue	Thyroid cyst	Stable compared to prior measurements	Y

ABD, abdominal limited; CBD, common bile duct; FF, free fluid; GB, gallbladder; HCG, human chorionic gonadotropin; IUP, intrauterine pregnancy; mo, months; MSK, musculoskeletal; N, no; non-OB, nonobstetric; OB, obstetric; POC, products of conception; RUQ, right upper quadrant; SAB, spontaneous abortion; VTX, vertex; wga, weeks gestational age; Y, yes.

^a

RUQ pain was evaluated to include the kidney, liver, and long/short views of the gallbladder, the common bile duct was not evaluated in the absence of a sonographic Murphy’s sign.

There is a wide range of portable ultrasounds with varying cost based on quality and required software support. A cost assumption of $10,000 per unit is reasonable.²¹ To cover replacement parts or breakage, we assume each ship would purchase two units, each with a life expectancy of 7 years. Each ship averages 10 missions per year, providing care to 700 people per mission. Assuming POCUS prevents unnecessary evacuation at the same rate as our mission (1.2%), POCUS costs $34 per evacuation prevented.

Patients evacuated nonemergently are transported on the Navy ship free of charge. The patient must still pay out-of-pocket for at least two nights (minimum hotel cost $25/night; $50 for lodging) and pay for transportation home (average cost for a two-day river journey is $25), yielding a best-case cost of $75. However, the transitory nature of Riverine life leads to an emphasis on maintaining community; for this reason, should a Riverine patient travel for care they will typically travel with several family members. Assuming the patient travels with three family members, pays for their travel home from their definitive care ($100), and all stay in the same hotel room for two nights ($50), a more realistic cost of ship evacuation is $150. Evacuation by helicopter is much more expensive. The average hourly flight cost of the Bell Jet 206 helicopter used is $489.²² The average flight time in the Amazon for evacuation is 3 hours, one way. The helicopter flies the patient to definitive care and returns (6 hours, $2934) and must still pay for a hotel ($50) and return trip by boat ($25) for a total cost of $3009.

DISCUSSION

During this humanitarian assistance mission, POCUS was used in 3% of all patients, and changed management in 42% of patients scanned, or 1.2% of all outpatient visits. This is not statistically different than a similar POCUS impact reported by Blaivas et al.¹⁵ who reported that POCUS changed management in 0.9% of patients (1.2% versus 0.9%, P = 0.49 using a two-tailed χ² test to 95% confidence). In that study, a team of physicians provided humanitarian assistance care to remote indigenous tribes in the Amazon jungle. Like our mission, a primary management decision was whether or not a patient warranted evacuation to receive a higher level of care. Out of 800 patients seen in that study, 25 had POCUS scans (3.1%), 7 of which changed management decisions (0.9% of all patients).

Most literature on POCUS in austere environments describes remote emergency department settings or disaster relief missions.^3–9,12 Both of these settings should have a greater percentage of patients whose management changes with POCUS because of their expected higher levels of trauma cases requiring a higher level of care. For example, our results are lower than that reported by Stolz et al., who reported that POCUS played a significant role in 8% of patients seen in their humanitarian setting.¹² That study, however, evaluated POCUS use by nonphysicians in a remote emergency room in Uganda.^1,2,The 53.3% of their POCUS examinations were trauma examinations, which likely accounts for their higher impact. Other emergency and disaster relief missions—with their much higher traumatic injury prevalence—report POCUS impact in up to two-thirds of patients evaluated.^3,9,12,13,15 In contrast, over half of all POCUS consultations during our mission were referred for OB well examinations. This was likely because of the Brazilian obstetrician being more familiar with the utility of ultrasound in routine prenatal care. It also underscores a limited understanding of the versatility of POCUS and its diagnostic utility outside of OB care.

The purpose of POCUS examinations in nonemergent, nondisaster settings like ours is primarily to inform an answer to the clinical question, “Does this patient require referral?”¹⁰ Referral in this environment often involves a multi-day trip of hundreds of miles along the river, presenting a significant time and cost burden to patients, who typically pay for nonemergent transportation costs out of pocket. Reducing unnecessary referrals therefore offers patients and coordinating institutions significant benefit, and tools to enable this are a valuable augmentation to those who provide care.¹⁶ The cost of POCUS equipment ($34) compares favorably to the cost of evacuation ($75-$150 by boat, $3009 by helicopter). However, a limitation of this analysis is that we limited our cost to equipment and did not include the cost of training. This was intentional, as POCUS is increasingly part of standard residency training for primary care physicians.^2,5 However, for units without providers already training in POCUS, training costs may be prohibitive. Also, the cost evaluation does not include limitations on lines of funding; regardless of the net cost effectiveness, a unit without discretionary funds may not be able to procure POCUS.

POCUS may also serve to increase the urgency of evacuation. For example, consider our patient with a positive Murphy’s sign. With otherwise normal vital signs, nonemergent evacuation (2 days by boat) for further evaluation might be reasonable. In our case, POCUS prevented this evacuation by demonstrating an absence of pathology. However, should POCUS have revealed cholelithiasis with an impacted stone, the urgency of evacuation would indicate a need for helicopter transport for rapid surgical intervention.

Our results are from a single mission on a single river; POCUS impact may differ in other settings, limiting the generalizability of our results. Further, our point-in-time care lacks follow-up analysis on outcomes. It is possible that, based on POCUS, we did not evacuate a patient who in fact needed evacuation. Moreover, we did not communicate the full range of POCUS examinations available for consultation and may have missed opportunities for intervention. Prospective studies with longitudinal outcome data are needed to assess the net appropriateness of management changes predicated on POCUS.

A strength of our study is the practical utility of our approach over eight separate communities. Our study is generalizable to units or missions with personnel trained in POCUS with access to or funding for POCUS equipment. As the cost of these devices continues to decrease, and training in POCUS for primary care providers becomes more widespread, high resolution POCUS is increasingly available in lower-resource settings.^8,16

CONCLUSION

Although our 1.2% overall change in management is smaller than that of emergency and disaster relief impact, it still offers a significant benefit to patients. Our results offer a benchmark utility that may be used in assessing the cost-benefit of adding POCUS to humanitarian assistance missions. Given its low cost and high impact, POCUS may be considered an important component of humanitarian assistance missions.

ACKNOWLEDGMENTS

The authors are grateful for the support of the Captain and crew of NAsH Carlos Chagas, the Director of the Manaus Naval Polyclinic, the Ninth Naval District of the Brazilian Navy, the U.S. Navy’s fourth Fleet, and the exceptional photography of Mass Communication Specialist Chief Byron C. Linder.

FUNDING

No direct funding from any source. Point of care ultrasound device loaned from SonoSite.

Author notes

These data were presented as a poster at the 2019 Military Health System Research Symposium, Kissimmee, FL; MHSRS-19-02503; the 2019 Society of Federal Health Professionals (AMSUS) Annual Meeting, National Harbor, MD; and the 2019 American Academy of Family Physicians Global Health Summit, Albuquerque, NM.

The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the U.S. or Brazilian Department of the Navy, Department of Defense, or the Brazilian or U.S. Government.

Authors (Sullivan, Roman, Milder, Carter, and Lennon) are or were U.S. military service members. This work was prepared as part of their official duties. Title 17 U.S.C. 105 provides that “Copyright protection under this title is not available for any work of the U.S. Government.” Title 17 U.S.C. 101 defines U.S. Government work as a work prepared by a military service member as part of that person’s official duties.

De-identified data from this mission are maintained by the Brazilian ninth Naval District and are used with permission. Analysis and publication of these data were also approved by the Naval Medical Center Portsmouth Institutional Review Board. This work was conducted according the ethical principles delineated in the Declaration of Helsinki, 1975 (as amended.)