Aeromedical Evacuation*

Definition

A scheduled Aeromedical evacuation (MEDEVAC) is one available transportation option when the medical needs of a patient exceed the resources available in the local medical department or when medical needs can be better met at another military treatment facility (MTF) .  The needs of the patient must be balanced against the operational needs of the ship or unit. There are a number of factors that should be taken into account when considering air evacuation.

Do the benefits of air transport outweigh the risks to the patient and the aircrew?

• Available Services - Air evacuation should be considered only if local resources are not sufficient to meet the patient's needs, and the receiving facility can better meet those needs.

• Contraindications - There should be no medical or “aviation” contraindications to air transport.

• Transport Safety - An unstable patient should not, under normal circumstances, be transferred by air. An exception might be the patient who will not likely ever achieve stability in the present circumstances, and whose best chance for survival is prompt MEDEVAC.

What USN MTF’s are available?

Surface Combatant ships – Echelon I facility, these ships are manned by Independent Duty Corpsman.

Amphibious Primary Casualty Receiving Ships – Amphibious Assault Ships (LHD, LHA, LPH), Amphibious Transport Dock (LPD), Dock Landing Ship (LSD), Aircraft Carrier (CVN).

• LHD – Largest medical capability of any amphibious ship currently in use with 604 beds.  This ship is capable of receiving both helicopter and waterborne casualties.  

• LPH – This ship is currently being phased out of service.  It does not have the ability to launch or recover amphibious assault crafts or vehicles.  It has 218 to 222 beds.

CVN – The carrier has limited medical capability with 1 OR, 3 ICU beds, 8 isolation beds and 60 ward beds.

Combat Zone Fleet Hospital – This is an echelon III facility.  It is designated as either a 250 or 500 bed “ground based” facility.  The fleet hospital is based on a modular concept and is pre-positioned overseas.  It is difficult and logistically intensive to relocate.

Hospital Ship (T-AH) – This is an echelon III facility with 800 beds..  A floating hospital vested with the mission to provide acute medical care in support of combat operations at sea and ashore.  There are currently 2 ships, the USS Mercy and the USS Comfort stationed on the west and east coasts respectively.

Communications Zone Fleet Hospital – This is an echelon IV facility.  It is the same as a Combat Zone Fleet Hospital except located in the communications zone.  It is an OCONUS MTF.

What USMC MTF’s are available?

Battalion Aid Station (BAS) – Mission is to provide direct support to company and platoon corpsmen and to provide an advanced level of care in the overall effort to sustain the combat force.  It will operate as far forward as the tactical situation permits.  This is an echelon I facility.

Medical Battalion – Within the Marine Expeditionary Force the medical battalion is the primary source of medical support above the aid station level making this an echelon II facility.  It is highly mobile and provides 260 beds. 

Echelons III and IV care is provided by USN MTF’s.

What aeromedical evacuation assets are available?

CH-46 Sea Knight – Max 15 litter or 22 ambulatory casualties with 2 corpsmen.  Combination 6 litter and 15 ambulatory casualties with 1 corpsmen.

CH-53 D/E Sea Stallion – Max 24 litter or 37 ambulatory casualties with 2 corpsmen.  Combination 8 litter and 19 ambulatory casualties with 2 corpsmen.

C-2 COD – Not equipped to evacuate litter patients.  Max 28 ambulatory patients with 2 corpsmen.

P-3 Orion – Max 10 litter or 19 ambulatory casualties with 2 corpsmen.

V-22 Osprey – Max 12 litter or 24 ambulatory casualties and 2 corpsmen.

Landing Craft Air Cushion (LCAC) – Capability of 100 litter patients.

Does the referral MTF accept the patient?

Once the benefits and risks are considered, the need for air evacuation is determined, and the medevac aircraft is available, the transferring MTF should ensure a physician at the referral MTF will accept the patient.  However, such notification and acceptance may sometimes be impossible due to operational or military security reasons.

Who should go?

Optimally, air medical transport personnel should consist of a dedicated, specially trained team, expertly capable of taking care of the patient’s medical needs, while also paying attention to special aviation environmental concerns that may affect the patient directly or indirectly.  When taking these latter factors into consideration, optimual air evacuation may not be practical or possible.  Personnel considerations are included in the following list:

• The size and configuration of the medevac aircraft platform

• No specific aeromedical training is required, but some training is encouraged for medical professionals attending medevacs.

• Ideally, the medical attendants should be familiar with the patient, care requirements during the transport, and the transport environment.   However, in the case of small vessels with no medical officers (e.g. Cruiser, Destroyer, and Frigate), a trained attendant will accompany the patient.

• Ideally, two medical attendants should accompany the patient (e.g., inflight medical technician and flight surgeon).

• If the medical condition warrants, medical professionals with the ability to provide advanced airway management including basic and advanced cardiac life support (ACLS), if available,  should be in attendance.

• If a nonphysician is the attendant, means to communicate with a physician concerning changes in the patient's status should be available.  If such communication is not technically possible, a registered nurse or advanced emergency medicine technician (EMT) should be in attendance with preauthorized standing orders to perform advanced cardiac life support (ACLS) measures if they become necessary.

• Provision of the medical attendants is the responsibility of the transferring MTF. The transferring MTF is responsible for the patient until arrival at the referral MTF when the “accepting physician” assumes the care.

• Patients transported on a cardiac monitor require a physician or specially trained nurse as the attendant.

• Patients on a ventilator require a physician that is familiar with the equipment.  Optimally a respiratory therapist should also be in attendance.

• One non-medical attendant may accompany a patient if deemed necessary by the referring MTF.

What supporting resources do you need?

• Medical providers to coordinate the transfer with the available medical personnel (medical specialists and with physicians trained in aviation medicine, such as flight surgeons).

• Medical equipment and monitors, medications, communication resources, and oxygen.

• Aviation assets.  Prepare patient appropriately, depending on what aircraft platform or platforms are available for transport, and which one is optimal, given the patient’s condition.  (consult with a flight surgeon, SAR corpsman or the flight crew).

What specific steps need to be taken to complete a successful aeromedical evacuation once the need is determined and resources are available? 

The checklist should include:

q Notify the chain of command.  Although the medical officer has direct access to the commanding officer, don’t forget to notify the executive officer at the same time.  Also talk with the operations officer and the airboss.  This will make transport logistics an easier process.  

q Contact the referral MTF medical specialist and brief him/her on the case.

q Obtain an “accepting physician” at the referral MTF and document this in the medical record.

q Initiate air evacuation message traffic (as applicable).

q Complete the medical record in detail.

q Copy all pertinent information and collate into a transfer package (e.g., labs, x-rays, pertinent medical record, narrative summary, etc.).

q Complete all transferring MTF forms as directed by transferring command.

q Complete consult form:  Referral for Civilian Medical Care DD 2161 and/or SF 513, if applicable.

q Contact the duty flight surgeon or medical officer in charge of medevacs.

q Have the officer of the day contact the duty search and rescue (SAR) corpsman to assist in coordination of the transfer, if applicable.

q The flight surgeon should determine type of attendants needed (anesthetist, obstetrician, EMT, etc.).

q Assure coordination for the receiving facilities ambulance.  If the patient cannot be flown directly to the hospital, an ambulance transport must be prearranged to transfer the patient upon arrival.

q Discuss plans and obtain consent from family members (civilians) as applicable.

q Contact the Fleet Liaison Services Office when necessary (foreign military, U.S. military shipboard or detached personnel, embassy personnel and their dependents, etc.).

q Assemble all necessary information and medical equipment.

q Prepare the patient appropriately for transportation in the designated aircraft platform.

What are some specific medical equipment considerations?  Assume the worst case scenario.

• Cardiac monitor

• Oxygen (portable cylinder, masks, tubing, etc.)   Ensure an adequate supply of full portable oxygen cylinders is available.

• Pulse oximeter and C02 monitor if available

• Suction device, electric and manual

• Airway kit (laryngoscope, endotracheal tube, bag-valve mask, etc.)

• Medications:  ACLS drugs and/or those specific to each case.

What patient information should be included in the transfer package?

1. Brief history and physical exam (H&P to include time, mechanism, severity, allergies, past medical history, type of work.)

2. Brief narrative summary, current medications, and last meal

3. Labs, medical records, x-rays, and other supporting data

4. Transfer summary flow sheet:  record all fluids and medications given.

 Useful Documents

Aeromedical Transfer Checklist (MEDEVAC)

1. ____ Show Time:_________ (Ensure Aircrew is briefed on Patient & Equipment)

2. ____ Meet at bedside 2 hours prior to launch. Brief Aircrew to include appropriate clothing, which elevator to be used (Navy), Helo loading, emergency procedures

3. ____ Checklist of items at bedside and packed for transport

Patient Preparation

1. ____ Empty urine bag if applicable

2. ____ Switch IV's to portable infusion Pumps or "Dial-a-Flow" if to be used

3. ____ Label all IV bags and lines and infusion pumps

4. ____ Coil and tape all long IV lines

5. ____ Obtain baseline Readings on invasive pressure monitors

6. ____ Pressure infusion Bags over IV bags

7. ____ Insert NG tube & Foley catheter if required.

8. ____ Check ETT and all other catheters for water vice air in balloons.

9. ____ Attach Heimlich valve and vented collection bags on chest tubes, NG Tubes, Surgical drains.

10. ____ Place BP cuff on arm (non-IV arm preferably)

11. ____ Ready patient with required floation gear, head gear, hearing potection, eye protection.

12. ____ Restrain patient on litter as needed

13. ____ Attach cardiac monitor leads

14. ____ Protect from anticipated environment: Cold, Heat, Wind, Rain

15. ____ Switch O2 line to transport source

16. ____ Give last dose of any scheduled medications

17. ____ Obtain and record first set of transport vital signs

18. ____ Brief patient on flight: explain loading and unloading, noise level, how to communicate his complaints in the aircraft

Altitude Pressurization Table

 (Altitude in PSI - Max Aircraft pressure differential PSI = Cabin PSI)

Summary - Communication is the key! Ensure each patient is stable and rule out any contraindications before transport.  See the summary algorithm on the next page.

Suggested web sites for further aviation related information:

            http://www.aerospacemed.org

http://www.nomi.navy.mil

http://bumed.med.navy.mil/med23/default.htm

Medevac Assistance:

                DSN 576-6261

Original Submission by: LT W.P. Baugh, MC, USN, Flight Surgeon.  Revised by CAPT Charles O. Barker, MC, USN, Bureau of Medicine and Surgery MED-23,Washington, D.C.(1999).  Revised again by LT E.H. Chin, MC, USNR, Flight Surgeon (2000).

*Source: Operational Medicine 2001,  Health Care in Military Settings, NAVMED P-5139, May 1, 2001, Bureau of Medicine and Surgery, Department of the Navy, 2300 E Street NW, Washington, D.C., 20372-5300