Linda E. Pelinka, MD, PhD Medical University of Vienna a nd Ludwig Boltzmann Institute

1. TRAUMA “Is there a MEDICAL PROFESSIONAL ON BOARD this aircraft?”Challenges at 35.000 ft Linda E. Pelinka, MD, PhD Medical University of Vienna and Ludwig Boltzmann Institute for Experimental & Clinical Traumatology Vienna, Austria, European Union

2. Basics • Pathophysiology • Medical Equipment • Common problems • Emergencies • Legal Aspects

3. Basics

4. Statistics • Worldwide, ~1 million people are traveling by air at any given time • >700 million Americans travel by air in the US • ~one per 10-40,000 passengers will experience an medical emergency. U.S. Federal Aviation Administration. Moving America safely: annual performance report 2005. http://www.faa.gov/air_traffic Sand M et al. Surgical & Medical Emergencies on board European Aircraft:10189 cases. http://ccforum.com/content/13/1/R3

5. >50% of passengers age 50 or over have at least one health issue(s) Emergencies will become more frequent as % of elderly increases Goodwyn T: In-flight Medical Emergencies: an Overview. Brit Med J 2000; 321:1338-41

7. There are more deaths from in-flight medical emergencies than from airline accidents. In2006: 550 medical diversions 59% were 50 or older 63 passengers died in-flight National Transportation Safety Board and Med Aire

8. In the Air, Health Emergencies rise quietly USA TODAY, Dec 2008 The death of an AA passenger flying from Haiti to NYC has cast a spotlight on the growing number of medical emergencies on commercial jets, a trend that has escaped public notice because airlines aren’t required to report such incidents. A MedAire analysis shows that such incidents nearly doubled from 2000-2006, from 19 to 35 per million passengers. 1 of 2

9. In the Air, Health Emergencies rise quietly USA TODAY, Dec 2008 According to analysts, this is due to 2 factors: • 79 million baby boomers are entering retirement, but continue traveling habits established when they were young. • Flights are going farther and lasting longer. Av. length of a flight in 2000: 1,233 mi Av. length of a flight in2006: 1,347 Max flying time today: 20 hrs 2 of 2

10. “if you are ill, an airplane is the worst place to be… “… you are trapped at 35,000 ft.” David Stempler President of the Air Travelers’ Association.

11. Pathophysiology

12. Setting on Board: passenger’s point of view • Very cramped everywhere (seat, restroom) • Three-dimensional motion of aircraft • Very dry

13. Dehydration • Hemoconcentration & hyperviscosity increase risk of thromboembolism • The mild hyperbaric changes during flight are sufficient to cause increased activation of coagulation in healthy individuals with no thrombophilia compared with that in individuals seated and not moving at ground level. Toff WD et al: Effec of hypobaric Hypoxia, simulating Conditions during long-haul air travel on Coagulation, Fibrinolysis, Platelet Function and Endothelial Activation. JAMA 2006; 295: 2251-61.

14. Humidity • Low, typically 10-20% • Low humidity has a propensity to exacerbate reactive airway disease and dehydration Hocking MB: Passengr Aircraft Cabin Air Quality: Trends, Effects, SocietalCosts, Proposals. Chemosphere 2000; 41:603-15

15. Commercial cruising altitude 7010-12,498 m

16. Cabin Pressurization to 2438 m:What happens? Atmospheric cabin pressure drops PaO2 drops from 95(12.7 kPa) to 65mmHg (8.7 kPa) Oxyhemoglobin sat drops from 95-100% to 90% Humpreys S et al: Effect of high Altitude Commercial Air Travel on O2 Saturation. Anesthesia 2005; 60: 458-60

17. The passenger cabin is pressurised to 1524—2438 m. This reduced pressure within the passenger cabin results in lower syst. PaO2 and oxyhaemoglobin (oyx-hb). For most healthy passengers, this results in a decrease in the arterial partial pressure oxygen tension. (A) The aircraft passenger cabin is normally pressurised to an altitude of 1524—2438 m. This reduced pressure within the passenger cabin results in lower systemic PaO2 and decreased oxyhaemoglobin. For most healthy passengers, this results in a decrease in the arterial partial pressure oxygen tension from 95 mm Hg (12·7 kPa) to 65 mm Hg (8·7 kPa) corresponding to an oxyhaemoglobin saturation from 95—100% at sea level (A) to 90% at a cabin altitude of 2438 m (B). Silverman D, Gendeau M: Medical issues associated with commercial flights. The Lancet 2009; 373/9680: 2067-77

18. Passengers with pre-existing lower sea-level oxy-hb sat have greater declines during flight. E.g., a passenger with mild COPD with a sea-level PaO2 of 70 mm Hg PaO2 to about 53 mm Hg or oxy-hb sat of approximately 84% at a cabin altitude of 2438 m Silverman D, Gendeau M: Medical issues associated with commercial flights. The Lancet 2009; 373/9680: 2067-77

19. Silverman D, Gendeau M: Medical issues associated with commercial flights. The Lancet 2009; 373/9680: 2067-77

20. pO2 Drop at various Altitudes 8 pO2 drop by ~30 mmHg between sea level and cabin press. level (2400m) vs~4 mmHg between 6000-8000m) Altitude in km 30 7 32 6 34 38 5 45 4 54 3 61 69 pO2 in mm Hg 2 73 81 1 89 100 0 20 40 60 80 100 120 mod acc to Stueben, U. Flugmedizin Med. WissenschaftlicheVerlagsges. Berlin, 2008

21. low cabin pressure lower alveolar pO2 (55-70 mmHg) lower arterial pO2 (~90%) increasing edema Curdt-Christiansen, C. et al: Principles and Practice of Aviation Medicine. World Scientific, London, 2009.

22. Effect of Aircraft-Cabin Altitude on Passenger Discomfort Muhm JM et al. N Engl J Med 2007; 357: 18-27 The frequency of reported complaints associated with acute mountain sickness (fatigue, lightheadedness and nausea) increased with increasing altitude and peaked at 2438 m. Most symptoms became apparent after 3-9 hrs of exposure.

23. Cabins in new Airbus A380, Boeing 787, pressurized at 1829 m

24. Hypoxia Preexisting cardiac and/or pulmonary and/or psychological issues Cabin pressure Mild Hypoxia

25. 68-Year-)ld woman with Chest Pain during an Airplane Flight • History of hypertension and hyperlipidemia • Flight from the Middle East to Europe: Gradually developing chest pain and pressure, fluctuating intensity, not radiating. Resolves spontaenously after several hours • Subsequent flight Europe to U.S.: Chest pain recurs. Picard, MH et al. New Engl J Med 2010; 363/27: 2652-61.

26. Is Air Travel Safe for those with Lung Disease? Coker RK et al. EurResp J 2007; 30: 1057-63 This prospective, observational study showed that 18% of passengers with COPD have at least mild respiratory distress during a flight.

27. Cramped Space & Immobilization • Have been linked to 75% of all air-travel cases of venous thromboembolism • Greatest frequency of theomboembolism in non-aisle seats Cesarone MR et al: Venous Thrombosis from Air Travel: the LONFLIT3 Study – Prevention with Aspirin vs LMWH in high-risk subjects. Angiology 2002; 53: 1-6.

28. Thromboembolism • Risk peaks up to four-fold when flight duration >8 h • Risk factors: Dehydration, immobility, hypobaric hypoxia, obesity, malignancy, recent surgery, h/o hypercoagulable state • Oral contraceptives increase risk 16-fold • Business vs coach class no effect on incidence Aryal KR & Al-Khaffaf H. Eur J VascEndovascSurg 2006; 31: 187-99. Jacobson BF et al. S Afr Med J 2003; 93: 522-528.

29. Boyle’s Law The volume occupied by a gas is inversely proportional to the surrounding pressure. Thus, at cruising altitude, gas in body cavities expands by 30%:

30. Boyle’s Law & Barotrauma • Healthy passengers minor abdominal cramping, ear pressure • Passengers after recent surgery Bowel perforation, wound dehiscence

31. Guidelines Delay flying for • 12 h after scuba diving (1 dive) w/o deco • 24 h after several dives or 1 dive + deco • 7-10 dys after diverticulitis • 2 wks after major surgery Medical Guidelines for Airline Travel, 2ndEdn. Aviat Space Environ Med 2003; 74 (suppl): A1-A19

32. Boyle’s Law & Effect on Medical Equipment Gas expansion in • Pneumatic splints • Urinary caths • Feeding tubes • ET tubes (instill water instead of air)

33. Medical Equipment

34. Emergency Medical Kit

35. Emergency Medical Kit

36. Emergency Medical Kit

37. Emergency Medical Kit

38. Opioids- Nalbuphine and Morphine – are provided by some carriers

39. Emergency Medical Kit

40. Oxygen Masks and nasal tubes available on board. Emergency bottles provide O2 at a fixed rate of 4 liters/min. Sufficient for 75 min.

41. Medication and technology are expensive but may still be cost-effective Diversion can cost from US$10,000 to $100,000 depending on the route

42. Equipment Challenges • Auscultation (pulm., BP) difficult due to ambient engine noise. Alternative: radial pulse palpation for syst BP. • Aviation portable O2 bottles have only 1 of 2 settings: “low”=2 l/min and 4 l/min=“high flow”, far lower than flow used for EMS. • O2 tubing for bag-valve resuscitation are not required to be compatible with these on-board O2 bottles.

43. Equipment Challenges • AEDs on board not required to have ECG screen, though ACLS meds are provided. • When AED does have screen, it is limited to a leads II/paddles view. • Glucometersnot mandatory, though 50% dextrose is. Ask if any passenger on board would be willing to share personal glucometer.

44. Equipment Challenges Since 9/11, phones have been largely removed from cabins and cockpit doors have been secured. Info must be relayed via intercom • from the back of the plane • or via flight attendant’s headset to pilots, who then relay info to doctors on the ground

45. AEDAutomatedExternal Defibrillator • AA first US airline to equip its fleet in 1997, first cardiac arrest save 1998. • Mandatory for US commercial carriers. (Aviation Medical Assistance Act). • Aircraft with inoperable AEDs are allowed to make “a few flights” until a replacement can be found.

46. AEDAutomatedExternal Defibrillator • AEDs are still not mandatory for European commercial carriers (European Aviation Safety Agency). • No AEDs on Intercity aircraft in Europe.

47. Positioning the Patient • Remove patient from seat, gripping him/her from behind.

48. Positioning the Patient • If possible, position potential emergencies next to the aircraft’s door or in the galley, horizontal to flight direction against front wall. • Make sure all trolleys are secured. Stueben, U. Flugmedizin/Flight Medicine. MedizinischWissenschaftlicheVerlagsgesellschaft Berlin, 2008

49. Make sure there is enough space behind pat’s head in case of intubation • Make sure there is enough space beside pat’s chest in case of cardiac massage

50. Telemedicine: MedAire Ground-based service utilized by airlines. VHF radio or satellite phone contact to ED physicians at MedAire. Arizona-based company providing emergency med advice to airlines carrying ~half of the 768 million passengers on US flights each year. Takes responsibility for deciding if flight diversion is appropriate.