Portable Ultrasound for Remote Environments

Bret P. Nelson, MD, RDMS(Department of Emergency Medicine,

Mount Sinai School of Medicine, New York, New York)

Edward R. Melnick, MD(Department of Emergency Medicine,

North Shore University Hospital, Manhasset, New York)

James Li, MD(‡Department of Emergency Medicine,

Miles Memorial Hospital, Damariscotta, Maine)

Part 1 Feasibility Part 2 Current

Indications

Hypothesis

• 1. Portable ultrasound used at bedside in hospitals can be useful when extrapolated into a wide variety of environments.

• 2. There are a variety of ultrasound applications in out-of-hospital arenas that have meaningful use in impacting diagnosis and management.

(Review Articles)

Part 1: Feasibility• Portable Ultrasound = Great Promise

– military combat support hospital– developing counties– outer space– pre-hospital helicopter transport – More…

• Use in Developing Areas– Cameroon

• made dx 32%• Confirmed/exclude 36% • wrong 4.6%.

– Tanzania and Rwanda• most common indication =• gravid/non-gravid pelvic.

Part 1: Feasibility• Tele-radiology

– US images transferred to distant interpreter •by radio transmitter, satellite or 3G network

• Machine Specifications Improving weight, bulk, cost – environment extremes– reasonable battery life– image quality in ambient light– ease of use

Part 2: Current Indications

• Trauma evaluation (FAST) • ICP Assessment

– Optic n. 5mm+m (sens.100%, specif 63-95%

• Casualty triage• Pneumothorax• Acute mountain sickness• Abdominal pain• Extremity injury

– US to detect bone fx?

Part 2: Current Indications

• Other indications – have good hospital-use basis – likely useful out of hospital– need more evidence.

• confirm placement of ET tube (lung slide or see it directly)

• diagnosing DVT• vascular access

• abscess vs. cellulites.

Research Question

• 1. Is use of portable US feasible

(practical & reliable)

in remote environments?

• 2. What ultrasound applications in out-of-hospital environments have evidence to support there usefulness?

Sampling Method • 1.

Unknown• 2. MEDLINE search

– “ultrasound,” “sonography,” “portable,” “field,” “military,” “ambulance,” “EMS,” “disaster,” “austere,” “mountain,” “medic,” and “helicopter.”

• references from appropriate articles • authors of studies contacted for

further references• journal search

– (EM, EMS, wilderness, medicine, trauma)

• Exclude case report if larger series on same topic

Independent Variable

• 1. Setting of US use • 2. Application of ultrasound

Dependent Variable

• 1. Practicality (transport, cost) and Usefulness (value added, Δ in management)

• 2. Exam Sensitivity, Specificity , Δ management, etc

Statistical Measurement Tool

• Sensitivity• Specificity• PPV• NPV

Is the Article Valid?

• External – is a focus of what this article is exploring: US has

indications in hospital setting, are those transferable to remote setting?

– wide range of environments with huge variables • altitude, gravity• Temperature• Training of users (3 hours session to several days)

• Internal– since it is a review, evaluate each study internally valid in

its particular environment– Most not randomized, small sample size

Is the Article applicable to our practice of Medicine?

• Here at OSUWMC– Portable ultrasound (not handheld, but not huge machine

the US techs use) is what is used in ED and on floors in hospital.

– Handheld if cheaper than current portable could make more available to residents within our hospital.

• Our Future Practice Environments– Military– Global Missions– Rural USA– Disaster relief

Example Images…

Distal Forearm

• Sonoguide

Colles Fracture

fractures of only a few millimeters displacement can be seen in

the cortical margin • Sonoguide

Rib Fracture

• Ultrasoundconnection.com

Ocular US

• Sonoguide

dilated optic nerve sheath measuring 5.3 mm. ↑ ICP

• Sonoguide