Physiological Foundation for Clinical Validation of Aeromedical Evacuation Patients
Abstract
This monograph brings together the physiological bases for clinical validation of aeromedical evacuation patients. The major physiological stressors --- acceleration/deceleration, humidity, hypothermia/hyperthermia, noise, vibration, hypobaria, and hypoxia --- are each described along with countermeasures available to the Theater Validating Flight Surgeon (TVFS). These discussions have been couched within an overarching algorithm from which the TVFS can clinically validate a patient "safe to fly." The monograph also offers up the Tissue Oxygen Delivery (DO2) paradigm for approaching the complex physiology of critically ill/injured, or stabilized patients, that are now routinely flown, often within 24-48 hours of illness/injury. This physiology is presented as well as the DO2-modifiable factors --- oxygen fraction of inspired air via supplemental oxygen, hemoglobin level via transfusion, and cabin altitude via cabin altitude restriction (CAR). In addition, the salutary impact on patient morbidity from prescribing within the DO2 paradigm is spotlighted. The conventional wisdom resisting liberal CAR prescribing is then discussed and, to some degree, discredited. Next, the monograph applies the Bradford Hill Criteria for causality to the epidemiological assertion: prescribing the DO2 paradigm reduces postflight patient morbidity. All nine criteria are met, albeit some strongly met and others less strongly. And, lastly, future directions in AE are discussed. Among the areas reviewed are the KC-46, remotely piloted vehicle casualty evacuation, modular unit AE, hyperbaric oxygen pretreatment, biostasis, and genetic modulation. In summary, this monograph, with its extensive reference list, broad-based toolkit, and graduated program of learning case series, proffers to the Flight Surgeon and TVFS not only an algorithm and paradigm for validating an AE patient, but also a means for coherently applying todays science to that prospective AE patient.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 23, 2020
- Accession Number
- AD1118264
Entities
People
- Lawrence W. Steinkraus
- William P. Butler
Organizations
- 711th Human Performance Wing
- Mayo Clinic