Accession Number:

ADA600081

Title:

Endotracheal Tube Cuff Management at Altitude

Descriptive Note:

Special rept. June 2012-Dec 2013

Corporate Author:

SCHOOL OF AEROSPACE MEDICINE WRIGHT PATTERSON AFB OH

Report Date:

2014-02-05

Pagination or Media Count:

15.0

Abstract:

Care of the mechanically ventilated patient during aeromedical transport presents a number of challenges owing to the impact of alterations in barometric pressure on gas volumes and gas density. Hypobarism reduces the partial pressure of oxygen in the atmosphere, which can lead to hypoxia and causes expansion of gas trapped in closed spaces. In the latter case, gas trapped in the body pneumothorax, bowel gas or in devices endotracheal tube ETT cuffs, pneumatic tourniquets expands during ascent and contracts on descent. We designed a model study of endotracheal intubation including mechanical ventilation and four methods of cuff pressure management during ascent and descent aboard a Critical Care Air Transport Team training flight. The results of this study confirm previous work demonstrating a significant rise in ETT cuff pressure during ascent to 8,000 feet. Our data also demonstrate that while filling the ETT cuff with saline reduces the impact of altitude-related changes in cuff pressure, the initial cuff pressure exceeds the pressure associated with interruption of mucosal blood flow. The passive-acting PressureEasy device reduced the altitude-related change in pressure but did not eliminate the pressure changes, nor could it prevent the low pressures seen on descent.

Subject Categories:

  • Medicine and Medical Research
  • Medical Facilities, Equipment and Supplies
  • Fluid Mechanics
  • Escape, Rescue and Survival

Distribution Statement:

APPROVED FOR PUBLIC RELEASE