Evaluation of Intensive Care Unit Ventilators at Altitude

Blakeman, Thomas; Rodriquez, Dario; Petro, Michael; Branson, Richard D.

doi:10.1016/j.amj.2017.05.001

Cited by 6 publications

(2 citation statements)

References 8 publications

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“…This supposed an enormous challenge to the Masi team as effects of high altitude on Masi ventilators were unknown and previous studies on ventilators used for air transport show significant effects due to altitude, in particular with regard to accuracy of tidal volume and breathing frequency [3]. In addition, tests performed in these studies to evaluate performance of ventilators at altitude have been made using a hypobaric chamber [4,5,6,7,8,9,10], but similar test in cities at high altitude could not be found.…”

Section: Introductionmentioning

confidence: 99%

Performance of the Masi Peruvian ventilator at high altitude

Pérez-Buitrago

Gomez-Alzate

Cordova

et al. 2021

2021 43rd Annual International Conference of the IEEE Engineering in Medicine &Amp; Biology Society (EMBC)

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In response to Covid-19 crisis, 310 Masi ventilators were produced and validated in Lima, Peru, according to applicable standards. Four of them, were transported to Puno, in order to strengthen ICU Services there, but this set a major challenge to Masi team as effects of altitude on ventilators were unknown. Once there, ventilators were acclimated and calibrated. Volume tidal, I:E ratio, respiratory frequency and PEEP were tested, all of them presenting errors under 15%, except for tidal volume, for which a 25% negative correction was applied. After the installation of a new version of Masi software, parameters were tested again, all of them presenting results with errors below 15%, which allowed the Masi team to take them to ICU services for use. Clinical Relevance-Masi Peruvian Ventilators are able to perform according to their specifications at extremely high altitude, after the adequate calibration. These devices are an alternative to treat COVID-19 patients in the middle of the crisis.

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Section: Introductionmentioning

confidence: 99%

Performance of the Masi Peruvian ventilator at high altitude

Pérez-Buitrago

Gomez-Alzate

Cordova

et al. 2021

2021 43rd Annual International Conference of the IEEE Engineering in Medicine &Amp; Biology Society (EMBC)

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“…Yet, with altitude there is a progressive reduction in barometric pressure and subsequently in oxygen pressure leading to major physiological adaptations in the lungs 9 , which are not usually considered in ventilator quality tests. Limited studies have compared the accuracy in tidal volume delivery of commercial ventilators at varying altitude and were all in the context of aeromedical evacuation 10,11 . In these tests, the majority of commercial ventilators failed at high altitude, delivering tidal volumes with up to 40% error from the set volume 10 .…”

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confidence: 99%

High-altitude populations need special considerations for COVID-19

2020

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The atmospheric pressure that decreases with altitude affects lung physiology. However, these changes in physiology are not usually considered in ventilator design and testing. We argue that high altitude human populations require special attention to access the international supply of ventilators. Humans are naturally adapted to live at low altitude. Yet,~2% of the world's population permanently live at altitudes above 2500 meters 1. The majority of these populations live in areas that are either poor, such as Ethiopia, Ecuador and Bolivia, or highly controlled, such as Tibet 1. The small market size and low economic power of these regions have left them aside in the design of biomedical equipment, which usually does not consider their special environmental conditions and physiological adaptations. Worldwide, there is a shortage of many goods including intensive care unit (ICU) beds, facemasks, and ventilators due to the COVID-19 pandemic 2. This shortage has led to an international "stock market"-like process of bidding for these goods, in which many countries are left at an extreme disadvantage 3. Several international organizations, including the International Monetary Fund, the World Bank, and others, have been encouraged to provide loans to developing countries, but access to these goods is an issue that goes beyond money. Many countries have enacted export restrictions, and small orders are usually rejected to give preference to large purchases from powerful nations 3. This reduces the capability of less-affluent nations in both treating COVID-19 patients and preventing the further spread of the disease. Diverse pathological mechanisms in COVID-19 are under investigation, and respiratory symptoms predominate in the clinic. Physiologically, SARS-COV-2 cell entry is dependent on the cellular expression of ACE2 and TMPRSS2, and SARS-COV-2 likely binds to, and replicates in epithelial cells after entering the nasal cavity 4. SARS-CoV-2 then spreads from the nasal cavity into the lungs where it primarily infects ciliated epithelial cells that line the conducting airways. As ACE2 expression and receptors are also found in cells outside of the lungs 5 and COVID-19 patients have been reported to suffer from non-lung-related illness 6 , it is likely that SARS-CoV-2 infection is not limited to the nasal cavity and lungs. However, the majority of COVID-19 related deaths are caused by pulmonary illness. Therefore, the lungs are the primary focus of COVID-19 treatment efforts. Ventilators are essential to treat COVID-19, as they are the primary equipment needed to assist the breathing and gas exchange of critically ill patients. To this end, ICU ventilators have become an expensive commodity that most countries have fought to access. These fights have left

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Patients Requiring Mechanical Ventilation

RodriquezJr.¹,

Branson

2019

Aeromedical Evacuation

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Evaluation of Intensive Care Unit Ventilators at Altitude

Cited by 6 publications

References 8 publications

Performance of the Masi Peruvian ventilator at high altitude

Performance of the Masi Peruvian ventilator at high altitude

High-altitude populations need special considerations for COVID-19

Patients Requiring Mechanical Ventilation

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