The Performance of Dräger Oxylog Ventilators at Simulated Altitude

Abstract

Ventilated patients frequently require transport by air in a hypobaric environment. Previous studies have demonstrated significant changes in the performance of ventilators with changes in cabin pressure (altitude) but no studies have been published on the function of modern ventilators at altitude. This experiment set out to evaluate ventilatory parameters (tidal volume and respiratory rate) of three commonly used transport ventilators (the Drager Oxylog 1000, 2000 and 3000) in a simulated hypobaric environment. Ventilators were assessed using either air-mix (60% oxygen) or 100% oxygen and tested against models simulating a normal lung, a low compliance (Acute Respiratory Distress Syndrome) lung and a high-resistance (asthma) lung. Ventilators were tested at a range of simulated altitudes between sea level and 3048 m. Over this range, tidal volume delivered by the Oxylog 1000 increased by 68% and respiratory rate decreased by 28%. Tidal volume delivered by the Oxylog 2000 ventilator increased by 29% over the same range of altitudes but there was no significant change in respiratory rate. Tidal volume and respiratory rate remained constant with the Oxylog 3000 over the same range of altitudes. Changes were consistent with each ventilator regardless of oxygen content or lung model. It is important that clinicians involved in critical care transport in a hypobaric environment are aware that individual ventilators perform differently at altitude and that they are aware of the characteristics of the particular ventilator that they are using.

Mechanical Ventilation in Neonatal Respiratory Distress Syndrome at High Altitude: A Retrospective Study From Tibet

“…The influence of a change in altitude upon different types of ventilators can also differ. Some ventilators provide a lower respiratory frequency, a higher tidal volume, and minute ventilation volume (15, 16), while others do not change significantly (17). This shows that the performance of different ventilators varies when exposed to high altitude.…”

Noninvasive Mechanical Ventilation in Helicopter Emergency Medical Services Saves Time and Oxygen and Improves Patient and Mission Safety: A Pilot Study

“…Bilevel noninvasive positive-pressure ventilation was the ventilatory mode used for all 20 patients because it is generally considered that there are no differences in clinical outcome between continuous positive airway pressure and bilevel positive airway pressure in COPD. 13,14 We started at a fractional inspired oxygen concentration (Fio 2 ) of 0.5 and subsequently adjusted Fio2 to the minimum required to achieve saturation of 92%. Five minutes after patients had received their treatment, the efficacy of SMT or NIV was evaluated.…”

Review article: Primary aeromedical retrievals in Australia: An interrogation and search for context

“…Another common focus in the literature was on airway management and equipment. 12,15,20,26,30,31 Such professional skill differences often define scopes of practice. 3 An emerging area of discussion relates to prehospital therapeutic agents such as muscle relaxants and the carriage of blood products.…”

“…11 AIS, Abbreviated Injury Score; GOS, Glasgow Outcome Scale; GSA, Greater Sydney Area; HEMS, Helicopter Emergency Medical Services; HIRT, Head Injury Retrieval Trial; ICU, intensive care unit; ISS, Injury Severity Score; NIPPV, noninvasive positive-pressure ventilation; NSW, New South Wales; REMS, Rapid Emergency Medicine Score; RTS, Revised Trauma Score; SAPS-2, Simplified Acute Physiology Score; TISS, Therapeutic Intervention Scoring System. Level II (n = 2) 22,24 Level II (n = 2) 22,24 Level III-2 (n = 3) 20,26,44 Level III-2 (n = 2) 28,41 Level III-2 (n = 1) 41 Level IV (n = 11) 12,15,16,25,[29][30][31]33,34,39,43 Level IV (n = 16) 11,13,14,[17][18][19]21,27,32,35,37,38,40,42,45 Level IV (n = 9) 2,13,21,31,35,37,45,46 Quality Reasonable (n = 5) …”