High (Hypoxic) Altitude Simulation Studies in the PFT Laboratory Katrina Hynes, BS RRT Asst. Supervisor – Mayo Clinic Pulmonary Function Labs Adjunct Faculty – University of Minnesota Rochester Katrina Hynes, BS RRT Asst. Supervisor – Mayo Clinic Pulmonary Function Labs Adjunct Faculty – University of Minnesota Rochester

Background: In-Flight Regulations Standard for airline cabin pressurization is regulated by the FAA. Standard for airline cabin pressurization is regulated by the FAA. (SAE ARP1270) (SAE ARP1270) The most important factor in this standard is that cabin altitude pressure not exceed more than 8000 ft. altitude in normal conditions. The most important factor in this standard is that cabin altitude pressure not exceed more than 8000 ft. altitude in normal conditions. Standard for airline cabin pressurization is regulated by the FAA. Standard for airline cabin pressurization is regulated by the FAA. (SAE ARP1270) (SAE ARP1270) The most important factor in this standard is that cabin altitude pressure not exceed more than 8000 ft. altitude in normal conditions. The most important factor in this standard is that cabin altitude pressure not exceed more than 8000 ft. altitude in normal conditions.

Background: In-Flight Regulations The FAA allows for brief drops in air pressure for safety purposes only, such as to avoid bad weather conditions. The minimum air pressure is equal to 10,000 ft. The FAA allows for brief drops in air pressure for safety purposes only, such as to avoid bad weather conditions. The minimum air pressure is equal to 10,000 ft. Average 6214 ft (range 0 – 8915 ft) Average 6214 ft (range 0 – 8915 ft) Cottrell JJ Chest 1988 (92) 81-4 Cottrell JJ Chest 1988 (92) 81-4 The FAA allows for brief drops in air pressure for safety purposes only, such as to avoid bad weather conditions. The minimum air pressure is equal to 10,000 ft. The FAA allows for brief drops in air pressure for safety purposes only, such as to avoid bad weather conditions. The minimum air pressure is equal to 10,000 ft. Average 6214 ft (range 0 – 8915 ft) Average 6214 ft (range 0 – 8915 ft) Cottrell JJ Chest 1988 (92) 81-4 Cottrell JJ Chest 1988 (92) 81-4

Background: In-Flight Regulations The Air Carrier Access Act of 1986 required the U.S. Department of Transportation to develop regulations to ensure that persons with disabilities are treated without discrimination in any way, consistent with the safe carriage of all passengers. The Air Carrier Access Act of 1986 required the U.S. Department of Transportation to develop regulations to ensure that persons with disabilities are treated without discrimination in any way, consistent with the safe carriage of all passengers. Air Carrier Access Act, 49 USC §41705 (1986). Air Carrier Access Act, 49 USC §41705 (1986). The Air Carrier Access Act of 1986 required the U.S. Department of Transportation to develop regulations to ensure that persons with disabilities are treated without discrimination in any way, consistent with the safe carriage of all passengers. The Air Carrier Access Act of 1986 required the U.S. Department of Transportation to develop regulations to ensure that persons with disabilities are treated without discrimination in any way, consistent with the safe carriage of all passengers. Air Carrier Access Act, 49 USC §41705 (1986). Air Carrier Access Act, 49 USC §41705 (1986).

Cramer D. Ward S. Geddes D. Assessment of oxygen supplementation during air travel. Thorax. 51(2):202-3, 1996 Feb. High Altitude Simulation Test (HAST) for Pulmonary Patients - Evidence A. Normal subjects A. Normal subjects B. Subjects with COPD B. Subjects with COPD Subjects with restrictive lung dz Subjects with restrictive lung dz

High Altitude Simulation Test (HAST) for Pulmonary Patients - Evidence SpO 2 measured with 4 L and following 5 min at FIO 2.21 in 3 pts with COPD Kramer et. al. Chest, Volume 108(5).November SpO 2 measured with 4 L and following 5 min at FIO 2.21 in 3 pts with COPD Kramer et. al. Chest, Volume 108(5).November

High Altitude Simulation Test (HAST) for Pulmonary Patients - Evidence 18 retired servicemen (age 68 +/- 6) with severe COPD (FEV1 31% +/- 10%) 18 retired servicemen (age 68 +/- 6) with severe COPD (FEV1 31% +/- 10%) Altitude simulation 8000 ft. in a hypobaric chamber. Altitude simulation 8000 ft. in a hypobaric chamber. PaO 2G at sea level of /- 9 mm Hg, PaO 2Alt of /- 6 mm Hg after 45 minutes of hypobaric exposure. PaO 2G at sea level of /- 9 mm Hg, PaO 2Alt of /- 6 mm Hg after 45 minutes of hypobaric exposure. PaO 2Alt = [PaO 2G ] [FEV1% predicted] (r = 0.847) PaO 2Alt = [PaO 2G ] [FEV1% predicted] (r = 0.847) Annals of Internal Medicine. 111(5):362-7, 1989 Sep retired servicemen (age 68 +/- 6) with severe COPD (FEV1 31% +/- 10%) 18 retired servicemen (age 68 +/- 6) with severe COPD (FEV1 31% +/- 10%) Altitude simulation 8000 ft. in a hypobaric chamber. Altitude simulation 8000 ft. in a hypobaric chamber. PaO 2G at sea level of /- 9 mm Hg, PaO 2Alt of /- 6 mm Hg after 45 minutes of hypobaric exposure. PaO 2G at sea level of /- 9 mm Hg, PaO 2Alt of /- 6 mm Hg after 45 minutes of hypobaric exposure. PaO 2Alt = [PaO 2G ] [FEV1% predicted] (r = 0.847) PaO 2Alt = [PaO 2G ] [FEV1% predicted] (r = 0.847) Annals of Internal Medicine. 111(5):362-7, 1989 Sep 1.

High Altitude Simulation Test (HAST) for Pulmonary Patients - Evidence Surveyed physicians in England Surveyed physicians in England 268 respondents 268 respondents No consensus exists regarding assessment methods or criteria for recommending oxygen R.K. Coker, M.R. Partridge. Eur Respir J 2000; 15: 128±130 Surveyed physicians in England Surveyed physicians in England 268 respondents 268 respondents No consensus exists regarding assessment methods or criteria for recommending oxygen R.K. Coker, M.R. Partridge. Eur Respir J 2000; 15: 128±130

High Altitude Simulation Test (HAST) Guidelines Managing passengers with respiratory disease planning air travel: British Thoracic Society recommendations - Evidence Based Thorax 2002;57:289–304 Purpose of recommendations (6) To enhance safety for passengers with lung disease traveling by air and reduce the number of in-flight medical incidents due to respiratory disease. Managing passengers with respiratory disease planning air travel: British Thoracic Society recommendations - Evidence Based Thorax 2002;57:289–304 Purpose of recommendations (6) To enhance safety for passengers with lung disease traveling by air and reduce the number of in-flight medical incidents due to respiratory disease.

High Altitude Simulation Test (HAST) BTS Guidelines To increase recognition among healthcare professionals that patients with respiratory disease may require clinical assessment and advice before air travel. To provide an authoritative up to date literature review of available evidence. To increase recognition among healthcare professionals that patients with respiratory disease may require clinical assessment and advice before air travel. To provide an authoritative up to date literature review of available evidence.

High Altitude Simulation Test (HAST) BTS Guidelines To provide consistent, practical, and comprehensive advice for healthcare professionals managing such patients. To formulate key research questions To promote the development of methods for monitoring the size of the problem To provide consistent, practical, and comprehensive advice for healthcare professionals managing such patients. To formulate key research questions To promote the development of methods for monitoring the size of the problem

High Altitude Simulation Test (HAST) BTS Guidelines Evidence definitions Evidence definitions

High Altitude Simulation Test (HAST) BTS Guidelines Ten Indications Severe COPD or asthma; [B] Severe restrictive disease (including chest wall and respiratory muscle disease), especially with hypoxemia and/or hypercapnia; [C] Ten Indications Severe COPD or asthma; [B] Severe restrictive disease (including chest wall and respiratory muscle disease), especially with hypoxemia and/or hypercapnia; [C]

High Altitude Simulation Test (HAST) BTS Guidelines Patients with cystic fibrosis; [C] History of air travel intolerance with respiratory symptoms (dyspnea, chest pain, confusion or syncope); [C] Co-morbidity with other conditions worsened by hypoxemia (cerebrovascular disease, coronary artery disease, heart failure); [C] Patients with cystic fibrosis; [C] History of air travel intolerance with respiratory symptoms (dyspnea, chest pain, confusion or syncope); [C] Co-morbidity with other conditions worsened by hypoxemia (cerebrovascular disease, coronary artery disease, heart failure); [C]

High Altitude Simulation Test (HAST) BTS Guidelines Pulmonary tuberculosis; [C] Within 6 weeks of hospital discharge for acute respiratory illness; [C] Recent pneumothorax; [B] Risk of or previous venous thromboembolism; [B] Pre-existing requirement for oxygen or ventilator support. [C] Pulmonary tuberculosis; [C] Within 6 weeks of hospital discharge for acute respiratory illness; [C] Recent pneumothorax; [B] Risk of or previous venous thromboembolism; [B] Pre-existing requirement for oxygen or ventilator support. [C]

High Altitude Simulation Test (HAST) BTS Guidelines Recommended assessment History and examination with particular reference to cardiorespiratory disease, dyspnea, and previous flying experience; [C] Spirometry [C] SpO 2 by pulse oximetry or ABG’s [C] Recommended assessment History and examination with particular reference to cardiorespiratory disease, dyspnea, and previous flying experience; [C] Spirometry [C] SpO 2 by pulse oximetry or ABG’s [C]

High Altitude Simulation Test (HAST) BTS Guidelines Blood gas tensions are preferred if hypercapnia is known or suspected. [C] In those who are screened who have resting sea level oximetry between 92% and 95% with additional risk factors, hypoxic challenge testing is recommended [C] Blood gas tensions are preferred if hypercapnia is known or suspected. [C] In those who are screened who have resting sea level oximetry between 92% and 95% with additional risk factors, hypoxic challenge testing is recommended [C]

High Altitude Simulation Test (HAST) BTS Guidelines

High Altitude Simulation Test (HAST) Gong H. at el coined the term Hypoxic Altitude Simulation Test (1984) Gong H. at el coined the term Hypoxic Altitude Simulation Test (1984) Premise: Altitude hypoxia is a primary stress or threat to patients with cardiopulmonary disorders and FIO 2 at altitude can be replicated according to known pressure-altitude relationships Premise: Altitude hypoxia is a primary stress or threat to patients with cardiopulmonary disorders and FIO 2 at altitude can be replicated according to known pressure-altitude relationships Monitored SpO 2 and ECG Monitored SpO 2 and ECG Gong H. at el coined the term Hypoxic Altitude Simulation Test (1984) Gong H. at el coined the term Hypoxic Altitude Simulation Test (1984) Premise: Altitude hypoxia is a primary stress or threat to patients with cardiopulmonary disorders and FIO 2 at altitude can be replicated according to known pressure-altitude relationships Premise: Altitude hypoxia is a primary stress or threat to patients with cardiopulmonary disorders and FIO 2 at altitude can be replicated according to known pressure-altitude relationships Monitored SpO 2 and ECG Monitored SpO 2 and ECG

High Altitude Simulation Test (HAST)- Methods Ideal test: Hypobaric chamber Ideal test: Hypobaric chamber Variable altitudes Variable altitudes Oxygen titration Oxygen titration Unaffordable and impractical Unaffordable and impractical Ideal test: Hypobaric chamber Ideal test: Hypobaric chamber Variable altitudes Variable altitudes Oxygen titration Oxygen titration Unaffordable and impractical Unaffordable and impractical

High Altitude Simulation Test (HAST)- Methods Modified body plethysmograph Modified body plethysmograph Exit port for gas flow Exit port for gas flow Controlled environment Controlled environment Oxygen titration? Oxygen titration? Modified body plethysmograph Modified body plethysmograph Exit port for gas flow Exit port for gas flow Controlled environment Controlled environment Oxygen titration? Oxygen titration?

High Altitude Simulation Test (HAST)- Methods Standard gas mixture cylinder Standard gas mixture cylinder Directional valve Directional valve Demand valve Demand valve Standard gas mixture cylinder Standard gas mixture cylinder Directional valve Directional valve Demand valve Demand valve

High Altitude Simulation Test (HAST)- Methods Blender driven with 100% N 2 and.21 Blender driven with 100% N 2 and.21 Variable FIO 2 Variable FIO 2 Oxygen analyzer Oxygen analyzer Reservoir Reservoir Directional valve Directional valve CPAP mask CPAP mask Blender driven with 100% N 2 and.21 Blender driven with 100% N 2 and.21 Variable FIO 2 Variable FIO 2 Oxygen analyzer Oxygen analyzer Reservoir Reservoir Directional valve Directional valve CPAP mask CPAP mask

High Altitude Simulation Test (HAST)- Methods Non-rebreathing mask Non-rebreathing mask Gas source Gas source Venti-mask Venti-mask Driven with 100% nitrogen 40% setting = approximately 14-15% Driven with 100% nitrogen 40% setting = approximately 14-15% Set to 35% = approximately 15-16% Set to 35% = approximately 15-16% Non-rebreathing mask Non-rebreathing mask Gas source Gas source Venti-mask Venti-mask Driven with 100% nitrogen 40% setting = approximately 14-15% Driven with 100% nitrogen 40% setting = approximately 14-15% Set to 35% = approximately 15-16% Set to 35% = approximately 15-16% “ Laboratory Assessment of Fitness to Fly in Patients with Lung Disease: A Practical Approach.” A.G.Robson, et al Eur Respir J 2000; 16:

High Altitude Simulation Test (HAST)- Methods Alternative altitudes Alternative altitudes Bengdag, China: 14,100 ft Bogota, Colomba: 8355 ft Quito, Ecuador: 9222 ft Telluride, USA: 9086 ft Alternative altitudes Alternative altitudes Bengdag, China: 14,100 ft Bogota, Colomba: 8355 ft Quito, Ecuador: 9222 ft Telluride, USA: 9086 ft Alternative Indications Athletic training

High Altitude Simulation Test (HAST)- Methods Determining the standard gas mixture at your altitude or for varying altitudes Determining the standard gas mixture at your altitude or for varying altitudes Factor = [ E-6 X Alt(Feet)]^5.256 Factor = [ E-6 X Alt(Feet)]^5.256 Bag FIO2 = ((760 X factor)/PBaro) X 0.21 Bag FIO2 = ((760 X factor)/PBaro) X 0.21 Determining the standard gas mixture at your altitude or for varying altitudes Determining the standard gas mixture at your altitude or for varying altitudes Factor = [ E-6 X Alt(Feet)]^5.256 Factor = [ E-6 X Alt(Feet)]^5.256 Bag FIO2 = ((760 X factor)/PBaro) X 0.21 Bag FIO2 = ((760 X factor)/PBaro) X 0.21 Mottram CD 10 th Ed. Ruppel’s Manual PFT Chap 5

High Altitude Simulation Test (HAST)- Methods Rochester, MN average barometric pressure = 740 mmHg Rochester, MN average barometric pressure = 740 mmHg Standard gas mixture for 8000 ft is 16.1% Standard gas mixture for 8000 ft is 16.1% Denver = 5,280 ft (“mile high city”) Denver = 5,280 ft (“mile high city”) Bag FIO2 = ((760 X factor)/PBaro) X 0.21 Bag FIO2 = ((760 X factor)/PBaro) X 0.21 Bag FIO2 = ((760 X.82495)/740) X 0.21 Bag FIO2 = ((760 X.82495)/740) X 0.21 Bag FIO2 = 17.8% Bag FIO2 = 17.8% Rochester, MN average barometric pressure = 740 mmHg Rochester, MN average barometric pressure = 740 mmHg Standard gas mixture for 8000 ft is 16.1% Standard gas mixture for 8000 ft is 16.1% Denver = 5,280 ft (“mile high city”) Denver = 5,280 ft (“mile high city”) Bag FIO2 = ((760 X factor)/PBaro) X 0.21 Bag FIO2 = ((760 X factor)/PBaro) X 0.21 Bag FIO2 = ((760 X.82495)/740) X 0.21 Bag FIO2 = ((760 X.82495)/740) X 0.21 Bag FIO2 = 17.8% Bag FIO2 = 17.8%

High Altitude Simulation Test (HAST)- Methods

High Altitude Simulation Test (HAST)- Methods Walking Walking BTS recommends walking if SaO % BTS recommends walking if SaO % O 2 Titration O 2 Titration Hypobaric Hypobaric chamber chamber Body box Body box Mask??? Mask??? Walking Walking BTS recommends walking if SaO % BTS recommends walking if SaO % O 2 Titration O 2 Titration Hypobaric Hypobaric chamber chamber Body box Body box Mask??? Mask???

16 patients with COPD were exposed to alveolar hypoxia in a hypobaric chamber (HC) at 2,438 m (8,000 ft) and with a HAST (method: mask) Conclusion: oxygen titration using an NC during a HAST causes accumulation of oxygen within the facemask and underestimates the oxygen dose required 16 patients with COPD were exposed to alveolar hypoxia in a hypobaric chamber (HC) at 2,438 m (8,000 ft) and with a HAST (method: mask) Conclusion: oxygen titration using an NC during a HAST causes accumulation of oxygen within the facemask and underestimates the oxygen dose required CHEST 2011; 140(1):84–90

High Altitude Simulation Test (HAST)- Methods BTS Guidelines – oxygen recommendations BTS Guidelines – oxygen recommendations Guideline threshold for advising in-flight oxygen: 82–84% 2 l/min via nasal cannula will improve hypoxemia but not quite to sea level values 4 l/min > sea level values BTS Guidelines – oxygen recommendations BTS Guidelines – oxygen recommendations Guideline threshold for advising in-flight oxygen: 82–84% 2 l/min via nasal cannula will improve hypoxemia but not quite to sea level values 4 l/min > sea level values

100 patients with COPD Thorax 2012;67:964–969

High Altitude Simulation Test (HAST)- Equipment Hypoxia gas delivery system and appropriate mixture Hypoxia gas delivery system and appropriate mixture Electrocardiograph and blood pressure system Electrocardiograph and blood pressure system Ratings of Perceived Exertion scale (RPE) Ratings of Perceived Exertion scale (RPE) Pulse Oximeter or ABG’s Pulse Oximeter or ABG’s Hypoxia gas delivery system and appropriate mixture Hypoxia gas delivery system and appropriate mixture Electrocardiograph and blood pressure system Electrocardiograph and blood pressure system Ratings of Perceived Exertion scale (RPE) Ratings of Perceived Exertion scale (RPE) Pulse Oximeter or ABG’s Pulse Oximeter or ABG’s

High Altitude Simulation Test (HAST)- Protocol Obtain resting room air variables Obtain resting room air variables ECG, RPE, B/P, SpO 2 ECG, RPE, B/P, SpO 2 Place on hypoxic mixture for 20 minutes or early termination criteria Place on hypoxic mixture for 20 minutes or early termination criteria Obtain hypoxic gas mixture variables Obtain hypoxic gas mixture variables ECG, RPE, B/P, SpO 2 /ABG’s ECG, RPE, B/P, SpO 2 /ABG’s Obtain resting room air variables Obtain resting room air variables ECG, RPE, B/P, SpO 2 ECG, RPE, B/P, SpO 2 Place on hypoxic mixture for 20 minutes or early termination criteria Place on hypoxic mixture for 20 minutes or early termination criteria Obtain hypoxic gas mixture variables Obtain hypoxic gas mixture variables ECG, RPE, B/P, SpO 2 /ABG’s ECG, RPE, B/P, SpO 2 /ABG’s

High Altitude Simulation Test (HAST)- Protocol Early termination criteria Early termination criteria Change in baseline rhythm (i.e. VT, SVT, PSVT) Change in baseline rhythm (i.e. VT, SVT, PSVT) ST – T wave depression > 1 mm ST – T wave depression > 1 mm SpO 2 < 80% SpO 2 < 80% Subject intolerance Subject intolerance Early termination criteria Early termination criteria Change in baseline rhythm (i.e. VT, SVT, PSVT) Change in baseline rhythm (i.e. VT, SVT, PSVT) ST – T wave depression > 1 mm ST – T wave depression > 1 mm SpO 2 < 80% SpO 2 < 80% Subject intolerance Subject intolerance

High Altitude Simulation Test (HAST)- Reporting

High Altitude Simulation Test (HAST)- Reimbursement “Show me the Money”

High Altitude Simulation Test Current Procedural Terminology (CPT) 94452: High Altitude Simulation Test (HAST), with physician interpretation and report 94452: High Altitude Simulation Test (HAST), with physician interpretation and report 94453: High Altitude Simulation Test (HAST), with physician interpretation and report; with supplemental oxygen titration : High Altitude Simulation Test (HAST), with physician interpretation and report; with supplemental oxygen titration : High Altitude Simulation Test (HAST), with physician interpretation and report 94452: High Altitude Simulation Test (HAST), with physician interpretation and report 94453: High Altitude Simulation Test (HAST), with physician interpretation and report; with supplemental oxygen titration : High Altitude Simulation Test (HAST), with physician interpretation and report; with supplemental oxygen titration.

Air Travel with Oxygen Does your airline accept passengers who require supplemental oxygen? Does your airline accept passengers who require supplemental oxygen? How much notice do you require before the flight? How much notice do you require before the flight? What documentation is required from my doctor? What documentation is required from my doctor? What do you charge for supplying oxygen and how is the charge determined? What do you charge for supplying oxygen and how is the charge determined? Does your airline accept passengers who require supplemental oxygen? Does your airline accept passengers who require supplemental oxygen? How much notice do you require before the flight? How much notice do you require before the flight? What documentation is required from my doctor? What documentation is required from my doctor? What do you charge for supplying oxygen and how is the charge determined? What do you charge for supplying oxygen and how is the charge determined?

Air Travel with Oxygen Do you allow passengers to bring their empty oxygen equipment? Do you allow passengers to bring their empty oxygen equipment? Are there specific seat requirements? Are there specific seat requirements? What liter flow options are available? What liter flow options are available? Do you provide nasal cannulas or masks? Do you provide nasal cannulas or masks? Do you allow passengers to bring their empty oxygen equipment? Do you allow passengers to bring their empty oxygen equipment? Are there specific seat requirements? Are there specific seat requirements? What liter flow options are available? What liter flow options are available? Do you provide nasal cannulas or masks? Do you provide nasal cannulas or masks?

Air Travel with Oxygen What to check once you’re on board? Oxygen cylinders are full Oxygen cylinders are full The oxygen equipment is working properly The oxygen equipment is working properly The flow meter has been set to the proper liter flow per minute The flow meter has been set to the proper liter flow per minute You have access to all of your medicines, including inhalers You have access to all of your medicines, including inhalers What to check once you’re on board? Oxygen cylinders are full Oxygen cylinders are full The oxygen equipment is working properly The oxygen equipment is working properly The flow meter has been set to the proper liter flow per minute The flow meter has been set to the proper liter flow per minute You have access to all of your medicines, including inhalers You have access to all of your medicines, including inhalers

Questions?Questions?