SELECTION OF PATIENTS FOR AERO-MEDICAL EVACUATION AND PATIENT CLASSIFICATION CODES AND PRECEDENCE

Patient classification codes provide information to evacuators and treatment personnel in an abbreviated form. They can be used to complete administrative reporting requirements pertaining to the evacuation of patients.

Patients selected for evacuation by air must be cleared for the proposed flight by the attending physician and/or health care provider at the OMF, staging element, or an en route care facility. The health care provider must balance fitness considerations with the availability of suitable in-flight medical care, urgency of treatment by the next echelon of care, and the operational capabilities of the available aircraft.

a. Forward Aero-medical Evacuation. The paramount need is to evacuate the patient from the point of injury to the initial point of treatment as quickly as possible. Helicopters will be used for airlift, and in these circumstances, the only available personnel will often be combat lifesavers trained in first aid or combat/flight medics. The principles for conducting evacuation in forward areas is discussed in STANAG 2087.

b. Tactical and Strategic Intra-theater and Inter-theater Aero-medical Evacuation. The benefit to the patient for evacuation to an area where appropriate MTFs are available must be balanced against the ability of the patient to withstand the anticipated environmental conditions of the flight.

(1) When AE is carried out with pressurized aircraft, appropriately fitted and carrying a trained in-flight medical crew, the patient is subjected only to minor mechanical disturbance and a slight degree of oxygen lack that can be countered with oxygen therapy.

(2) In wartime AE, however, conditions may often be much less favorable. Account must be taken of the effects on the prospective passenger of less significant changes in atmospheric pressure and cabin temperature, turbulence, and workload and capability of the in-flight medical crew operating with restricted facilities. Further, the type of aircraft and the flight plan (duration of flight and intervening stops) also impact on care and stability of the patients.

c. Clinical Selection Criteria. There are no absolute contraindications to AE. Each case must be judged on its merits, weighing the advantage to the patient of transfer against the possible harmful effects of the flight. Sometimes a calculated risk must be taken.

(1) However, as a guide it would be wise to accept the following types of patients only when there is no other acceptable means of transport:

Patients in the infective stage of serious communicable diseases. If any are carried, appropriate precautions must be taken for the protection of the other patients/crew members.

Sick and wounded patients whose general condition is poor and they may not survive the flight or whose medical condition will severely deteriorate.

Patients whose upper and lower jaws are immobilized. Such patients require constant supervision by persons who are competent and equipped to remove the tie materials immediately should the patient become airsick or vomit. Fixation by inter-maxillary elastics is preferable to wire because of the ease of cutting.

Pregnant patients beyond the 240th day of pregnancy are not routinely acceptable for AE, but may be moved if determined necessary to the patientís mental and/or physical health by competent medical authority.

(2) Patient with any of the following conditions require special consideration in selection for AE (particularly in un-pressurized aircraft [helicopter]):

Respiratory embarrassment. Patients whose unaided vital capacity is less than 900 milliliters (ml) should not normally be moved by air without a mechanical respirator.

Cardiac failure or early post-myocardial infarction.

Severe anemia (less than 2.5 million red blood cells [RBC] per cubic millimeter or less than 7 grams hemoglobin per 100 ml) estimated as near as possible to the proposed flight and not more than 72 hours beforehand.

Trapped gas within any of the body cavities (such as a pneumothorax).     Post-laparotomy or thoracotomy patients should not normally be moved within 10 days of operations except in pressurized aircraft.

Patients in plaster of paris casts should be escorted since limbs may swell during flight, necessitating bivalving of the cast. Casts applied less than 72 hours prior to the flight are to be of the GYPSONA type and are split (including all dressings) down to the skin level. Patients with lower limb plasters are normally litter cases unless the cast has been on for more than 7 days and there is no residual tissue swelling.

Detached retina, intraocular hemorrhage, or any choroidal or retinal injury.

Hypoxia can increase intraocular tension and cause meiosis.

Patients with subarachnoid hemorrhage should be moved either before 48 hours or after 6 weeks have elapsed.

Patients with vascular anastomosis should not be subjected to AE evacuation for 14 days.

(3) Patients with critical medical or surgical conditions (such as penetrating wounds or injuries of the chest or abdomen) should be stabilized if at all possible before AE.

When patients are evacuated by aircraft (routinely in Echelons III, IV, and V), they should be briefed on the following points:

a. A number of ambulatory patients will be detailed to assist with the evacuation of litter patients in any emergency.

b. Safety belts and litter straps are to be properly fastened in accordance with orders given by the pilot.

c. Patients are instructed on the proper position to assume in preparing for an emergency. Flight crews and CCAT ensure that seat safety harnesses have been tightened.

d. Ambulatory patients, with the exception of those designated to assist litter patients, are the first to leave a downed aircraft.

e. Immobilized litter patients are freed from litters and assisted in leaving the aircraft. Litters will not normally be removed from their fastenings in view of the limited time available to evacuate the aircraft.

f. Mentally disturbed patients should be quieted so that the orderly removal of other patients will not be jeopardized.

International Standardization Agreement Codes

Table K-1 provides the patient classification codes defined in international standardization agreements.

Patients for AE will be given appropriate degrees of priority so that, if aircraft space is limited, the more urgent patients may be evacuated before those whose conditions are less serious. The degrees of priority are depicted in Table K-2. (The evacuation precedence used by the USAF is essentially the same as this listing. It contains a few word changes and introduces specific time limits. It does not contain Priority 4.)

Table K-1. Patient Classification Codes 

Table K-3 provides the patient classification codes used aboard USAF aircraft and that can be used in completing DD Form 601 (Appendix H). These codes are expanded to include categories of patients and other personnel which may or may not apply on the battlefield (such as infants, relatives, or friends).

The evacuation precedence used by the USAF is dramatically different than that employed by the US Army medical evacuation system. These precedence should not be confused. Table K-4 provides the evacuation precedence and time frames used by the USAF.

Table K-3. Patient Classification Codes

Table K-3. Patient Classification Codes (Continued)