Medical air transportation with T-bird ventilator : don’t forget to input the cabin altitude!

Service de Santé des Armées Medical air transportation with T-bird ventilator : don’t forget to input the cabin altitude! Jean-Pierre Tourtier , Thomas Leclerc, Marc Borne Militaryhospital Val-de-Grâce, Paris, France

Introduction (1): • Ventilator T-bird VS02 • cabin altitude value should be manually input • Hypobaric • Vt set vs Vt delivered • With input of cabin altitude • Without input of cabin altitude

Introduction (2):

Methods (1): • Cabin altitude simulation

Methods (2): • Altitude simulated: • 1500 m (4000 feet) • 2500 m (6700 feet) • 3000 m (3000 feet)

Methods (3): • Lung simulation: VT1 Bioteck • Normal lung: • (resistance : 5.6 cm H2O/L/min ; compliance : 50 ml/cm H2O)

Methods (4): • Ventilation parameters:

Measurements: • Actual Vt: • Fleisch pneumotachograph / computer • Actual respiratory rate • Statistical analyze: • 3 measures • Mean +- SD • t test (Vt set vs Vt delivered): p <0.05 Methods (5):

Results (1): T-bird VS02 with input of cabin altitude Vt=400 ml

Results (2): T-bird VS02 without input of cabin altitude Vt=400 ml

Results (3): T-bird VS02 with input of cabin altitude Vt=700 ml

Results (4): T-bird VS02 with input of cabin altitude Vt=700 ml

Discussion (1):T-bird VSO2: is it a « good » ventilator for air transport ? • With altitude: Vt decreased • Significantly: at 1500 m • > 10%: at 2500 m • don’t forget to input the cabin altitude!

Discussion (2):What is a « good » ventilator for ground transport? • Lightweight package • Small volume • Various possible settings • Settings: respected • EASY TO OPERATE • Evaluations Benchmarking • Chipman et al. Performance comparison of 15 transport ventilators. Resp Care 2007

Discussion (3): specific stresses of flight • Vibration • Electromagnetic radiation • Electrical safety • Thermal and humidity conditions • Hypobaric

Discussion (3): How to evaluate ? • Laboratory evaluation • Vibration • Electromagnetic radiation • Electrical safety • Thermal and humidity conditions • Hypobaric Few studies, no benchmarking • Flynn et al. The performance of Dräger Oxylog ventilators at simulated altitude • Anaesth Intensive Care 2008 • Rodriquez et al. Effects of simulated altitude on ventilator performance. J Trauma 2009

Discussion (4): How to bring the evaluation to its completion ? • Real life • Systematic declaration of major dysfunction • Analyze of ventilators failures • Root Cause Analysis • Br Med J 2000; 320 :777-781 • Ann Fr AnesthRéanim 2002; 21 : 509 - 516

Conclusion • Highly specialized ventilators: ≠ T-bird VS02 • Evaluation • laboratory testing • real life • Highly trained personnel • Johannigman JA. Critical care aeromedical teams (Ccatt): then, now and what's next • J Trauma 2007

Medical air transportation with T-bird ventilator : don’t forget to input the cabin altitude!