He Forgot How to Fly Lt Col Lisa

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“He Forgot How to Fly” Lt Col Lisa Snyder 12 APR 2008 Team Aerospace

“He Forgot How to Fly” Lt Col Lisa Snyder 12 APR 2008 Team Aerospace Begins Here! 1

Overview § § § § § U-2 Aircraft Operational Parameters U-2 Physiology Initial DCS

Overview § § § § § U-2 Aircraft Operational Parameters U-2 Physiology Initial DCS Event RTFS Decision Flight Performance Second Physiologic Event ACS Evaluation and Disposition Food for Thought Questions and Discussion Team Aerospace Begins Here! 2

U-2 Operational Environment Crew: Cruise Speed: Range: Max Altitude: Mission Length: One 420 knots

U-2 Operational Environment Crew: Cruise Speed: Range: Max Altitude: Mission Length: One 420 knots Greater than 7, 000 miles Above 60, 000 feet Up to 14 hours Team Aerospace Begins Here! 3

U-2 Aviator Cockpit Environment § § § Full Pressure Suit-not continually inflated 100% Oxygen

U-2 Aviator Cockpit Environment § § § Full Pressure Suit-not continually inflated 100% Oxygen through helmet Aircraft cabin altitude 29, 000 ft Ozone toxicity-reduces lung diffusing capacity Emergency descent requires 35 minutes Team Aerospace Begins Here! 4

U-2 Standard Physiologic Protocols Pre-breathe § Exercise enhanced pre-breathe § Pharm Fatigue Management Program

U-2 Standard Physiologic Protocols Pre-breathe § Exercise enhanced pre-breathe § Pharm Fatigue Management Program § No-Go pills § Dextroamphetamine Gel § Caffeine pudding § Team Aerospace Begins Here! 5

A photo to wet your appetite……. Team Aerospace Begins Here! 6

A photo to wet your appetite……. Team Aerospace Begins Here! 6

Preparation for Flight MP had arrived to the deployed location 20 days prior §

Preparation for Flight MP had arrived to the deployed location 20 days prior § 1800 - MP took no-go and slept § Showed at 0350 § Pre-breathe begun at 0400 § Pilot: pre-breathe potentially delayed and shortened by initial regulator difficulty § Physiologists: pre-breathe time adequate without break § § Takeoff approx 0500 Team Aerospace Begins Here! 7

Mission Timeline TO and climb to FL 680(CA FL 295) - uneventful § TO

Mission Timeline TO and climb to FL 680(CA FL 295) - uneventful § TO + 3. 5 - Vertigo and sense of aircraft rolling § TO + 5. 0 -8. 5 - Bilateral knee pain- inflated suit - Frontal Headache- caffeine pudding - Fatigue - Confusion- notified mission cell - Began RTB with vectors -Turn right, Turn left, Stop turn - Attempted emergency O 2 activation § Team Aerospace Begins Here! 8

Mission Timeline (Cont) TO + 8. 5 - Vomited inside helmet (FL 680) -

Mission Timeline (Cont) TO + 8. 5 - Vomited inside helmet (FL 680) - Opened helmet - Attempted to close visor- successful? - Color vision and peripheral vision loss - MFDs unreadable Team Aerospace Begins Here! 9

Mirages scrambling to assist …… 10

Mirages scrambling to assist …… 10

Mission Timeline (Cont. ) TO + 1015 - Mirages find MP slumped in cockpit

Mission Timeline (Cont. ) TO + 1015 - Mirages find MP slumped in cockpit -MA is in graveyard spiral and stall -MP told to play follow the leader TO + 1030 - Traffic pattern entered - MP continues to follow Mirages without awareness of his proximity to the ground Team Aerospace Begins Here! 11

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 • 1 hour below 10, 000 ft • No memory of descent to

• 1 hour below 10, 000 ft • No memory of descent to airfield (~5 ft AGL) • MP’s awareness returns only after experiencing “ground rush” 15

Incident Timeline (Cont) § T + 11 - Gear handle lowered by feel -

Incident Timeline (Cont) § T + 11 - Gear handle lowered by feel - Landed successfully - FS found pilot slumped - Lethargic and pale - Cockpit sprayed with vomitus - O 2, IV and monitor - Helicopter to Host Nation hyperbaric chamber - Neurologic DCS diagnosed Team Aerospace Begins Here! 16

Host Nation Hospital Treatment § Navy Table VI with 2 extensions Multiple episodes of

Host Nation Hospital Treatment § Navy Table VI with 2 extensions Multiple episodes of vomiting § Symptoms began to respond after third oxygen period § Unable to ambulate until after second dive § Total of 4 dives § Persistent symptoms during admission: § Headache § Mild confusion and difficulty with ADL’s § Team Aerospace Begins Here! 17

Host Nation Hospital Studies § MRI § § CXR, EKG and TEE § §

Host Nation Hospital Studies § MRI § § CXR, EKG and TEE § § Multiple punctate high signal intensities mainly involving bi-frontal areas, most likely due to ischemia Normal, no Patent Foramen Ovale EEG § Normal Team Aerospace Begins Here! 18

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Timeline § MD Mishap Day § MD + 7 Released from HN hospital §

Timeline § MD Mishap Day § MD + 7 Released from HN hospital § MD + 11 Symptoms resolved § MD + 15 Returned to CONUS by commercial air Team Aerospace Begins Here! 20

Should He Return to Fly? ? Team Aerospace Begins Here! 21

Should He Return to Fly? ? Team Aerospace Begins Here! 21

Incident Pilot § Demographics 47 year old male § Over 4000 Total Flying Hours

Incident Pilot § Demographics 47 year old male § Over 4000 Total Flying Hours § Over 30 in the last six months § § Past DCS History- First reported at ACS Five “joint only” DCS incidents – unreported § 1991 – hospitalized for 3 days “dehydration”. Does not recall landing. Retrospectively MP believed episode was possibly neuro- DCS § Team Aerospace Begins Here! 22

DCS Risk Factors § General-- Fatigue, age, and dehydration § § Altitude attained and

DCS Risk Factors § General-- Fatigue, age, and dehydration § § Altitude attained and duration at altitude MP risk factors Possible inadequate pre-breathe for age § Coexistent hypoxia from vomiting episode could potentiate neurological symptoms § Team Aerospace Begins Here! 23

AFI 48 -123 22 May 2001 § Recurrent decompression sickness (DCS) § Single episode

AFI 48 -123 22 May 2001 § Recurrent decompression sickness (DCS) § Single episode of DCS - no waiver § 72 hours DNIF § Consultation with USAFSAM Hyperbarics and MAJCOM is required § DCS with neurological manifestations - normal examination by a neurologist is required Team Aerospace Begins Here! 24

Policy Letter 22 Feb 2002 § Released the requirement for a waiver for recurrent

Policy Letter 22 Feb 2002 § Released the requirement for a waiver for recurrent DCS episodes so that a waiver will not be “forced” on an individual with a normal response to an abnormal environment. This change was in response to a flying community that was not reporting DCS episodes and this change was to reduce the fear of grounding. § Added that DCS cases having persistent residual symptoms should be submitted for a waiver at MAJCOM level if not operationally significant; AFMOA if there is potential operational impact. Team Aerospace Begins Here! 25

MP RTFS § Neurology Normal neurological exam § MRI revealed multi-focal frontal lobe gliosis

MP RTFS § Neurology Normal neurological exam § MRI revealed multi-focal frontal lobe gliosis § Further correlation and repeat exam requested § DNIF > 72 hours § MAJCOM informed § MD + 100 § § As Per AFI - RTFS Retrospective history obtained at ACSPilot expressed he wanted to fly, but silently concerned about returning to high altitude flying Team Aerospace Begins Here! 26

Interim Flying Experience Line returns aviator to flying status § Multiple T-38 flights without

Interim Flying Experience Line returns aviator to flying status § Multiple T-38 flights without incident § Two U-2 flights in dual seat aircraft at FL 680 § Solo low altitude U-2 flight – uneventful § Team Aerospace Begins Here! 27

Home Station Incident § Preflight, Take Off and climb to FL 680 uneventful §

Home Station Incident § Preflight, Take Off and climb to FL 680 uneventful § TO + 2. 5 – “Sudden wave of anxiety and confusion” - Sensation he was falling - Believed this was DCS and inflated suit - Declared emergency and RTB § TO + 3. 5 - Landed uneventfully feeling well Team Aerospace Begins Here! 28

Post Flight Care FS examined pilot and called “LEO FAST” § History provided to

Post Flight Care FS examined pilot and called “LEO FAST” § History provided to Davis Hyperbarics: § Currently asymptomatic pilot who had “anxiety like symptoms” that lasted several seconds on his first solo flight back in the U 2 after a DCS episode 6 months earlier. Symptoms resolved almost immediately and he was normal upon landing. FS stated pilot’s symptoms were similar to the previous “anxiety type episodes” on other flights. He had been on O 2 for 5. 5 hours by helmet or mask. § Recommendation: No hyperbaric treatment Team Aerospace Begins Here! 29

Post Flight § 36 hours later Severe, frontal and lasted 10 hours § Drove

Post Flight § 36 hours later Severe, frontal and lasted 10 hours § Drove to elevation of 2, 200 feet (+ 400 ft gradient) § § § Bilateral pain in hands Over next 3 weeks Multiple episodes of “feeling in the fog” and forgetfulness § FS documented an inability to spell “World” backwards § § Symptoms resolved after one month These symptoms were not acutely reported to USAFSAM Hyperbarics Team Aerospace Begins Here! 30

AFI 48 -123 V 3 5 Jun 2006 § Any episode of DCS which

AFI 48 -123 V 3 5 Jun 2006 § Any episode of DCS which produces residual symptoms after completion of all indicated treatment, or persists > 2 weeks § DCS episodes require 72 hours DNIF after completion of treatment § Consult base SGP and USAFSAM Hyperbaric Medicine on all cases of acute DCS Team Aerospace Begins Here! 31

AFI 48 -123 V 3 § Bends-only DCS that resolve completely within two weeks

AFI 48 -123 V 3 § Bends-only DCS that resolve completely within two weeks may be RTFS by local flight surgeon after consultation with base SGP and USAFSAM Hyperbarics and MAJCOM. § DCS with neurological involvement may be RTFS only after complete resolution is confirmed by neurologist OR USAFSAM hyperbaricist exam, and after consultation with USAFSAM Hyperbarics and MAJCOM. Team Aerospace Begins Here! 32

AFI 48 -123 V 3 § DCS cases with persistent residual symptoms require complete

AFI 48 -123 V 3 § DCS cases with persistent residual symptoms require complete evaluation and MAJCOM waiver. NOTE: Previous episodes of DCS do not modify or change requirements noted. Team Aerospace Begins Here! 33

Timeline § § § § MD MD + 7 MD + 11 MD +

Timeline § § § § MD MD + 7 MD + 11 MD + 15 MD + 100 MD + 165 MD + 185 MD + 300 Incident #1 (Mishap Day 0) Released from HN hospital Symptoms resolved Returned to CONUS Returned to Flying Status First flight after RTFS Incident #2 ACS evaluation Team Aerospace Begins Here! 34

ACS Evaluation The Aeromedical Consultation Service (ACS) was consulted for evaluation of neuropsychological symptoms

ACS Evaluation The Aeromedical Consultation Service (ACS) was consulted for evaluation of neuropsychological symptoms of unclear etiology following a high altitude flight in a patient with a history of recurrent decompression sickness (DCS) episodes including a type II neurologic DCS Team Aerospace Begins Here! 35

ACS Neurology Clinically normal gross neurologic exam § Stable MRI lesions consistent with gliosis

ACS Neurology Clinically normal gross neurologic exam § Stable MRI lesions consistent with gliosis (stroke) § § review of two studies, six months apart No PFO or pulmonary shunt § Further challenge to areas of gliosis could lead to transient defects becoming permanent § Risk of recurrent incapacitation and seizure > 1% per year § Team Aerospace Begins Here! 36

ACS Neuropsychology Branch No anxiety or lack of motivation to fly § No psychiatric

ACS Neuropsychology Branch No anxiety or lack of motivation to fly § No psychiatric diagnosis § Cognitive disorder with variable performance decrements § Clinically mild but aeromedically significant, especially in time pressured situations § Findings correlate with areas of brain injury found on MRI § Team Aerospace Begins Here! 37

ACS Ophthalmology § Acquired asymmetric Tritan (blue cone) color vision defect While prior detailed

ACS Ophthalmology § Acquired asymmetric Tritan (blue cone) color vision defect While prior detailed color vision analysis was not available, congenital Tritan defects are present in only. 008% of population § Blue cones are most susceptible to hypoxic events § Team Aerospace Begins Here! 38

Hyperbaric Medicine § Second episode of DCS The 36 hour symptom free period can

Hyperbaric Medicine § Second episode of DCS The 36 hour symptom free period can occur, though unusual § FS account and pilot’s story during evaluation have some differences § Of great concern is the prolonged duration of intermittent memory loss following incident #2 § § No studies demonstrate an increased risk for subsequent neurologic DCS episodes, HOWEVER… § 2 nd event after 4 re-exposures! Team Aerospace Begins Here! 39

ACS Summary 1. Recurrent neurologic DCS 2. Persistent multifocal areas of gliosis, most likely

ACS Summary 1. Recurrent neurologic DCS 2. Persistent multifocal areas of gliosis, most likely from hypoxia or inflammation 3. Neurocognitive impairment, aeromedically significant 4. Acquired mild, subclinical Tritan color vision defect Team Aerospace Begins Here! 40

ACS Recommendations 1. Disqualify – FCII duties 2. No waiver recommended for any flying

ACS Recommendations 1. Disqualify – FCII duties 2. No waiver recommended for any flying related duties 3. May require MEB based on clinical progression of neurocognitive deficits 4. ACS re-evaluation in 2008 offered to patient § No waiver reconsideration Team Aerospace Begins Here! 41

Food for Thought- DCS Policy • Does the current AFI guidance on DCS need

Food for Thought- DCS Policy • Does the current AFI guidance on DCS need to be readdressed? • How many DCS episodes is too many? • Should neurocognitive testing be required? • What is the role of MRI in Neurologic DCS evaluation? • Should neuro DCS with altered level of consciousness be considered under A 4. 24. 1. 3. 4: “All other loss or disturbance of consciousness. For rated personnel, waivers are considered by AFMOA/SGPA, only after evaluation at ACS” Team Aerospace Begins Here! 42

Food for Thought-Safety § Should SIB investigations be conducted for near fatal class C’s/E’s?

Food for Thought-Safety § Should SIB investigations be conducted for near fatal class C’s/E’s? § § Would this type of investigation lead to prevention of future mishaps? Neuro DCS Study Group? § ACS sponsored § All neuro DCS to ACS before waiver Team Aerospace Begins Here! 43

Food For Thought. Human Systems Integration § High risk population for color and peripheral

Food For Thought. Human Systems Integration § High risk population for color and peripheral vision loss due to DCS and Hypoxia so: “Use the round Dial” –BUT…. there is not one Team Aerospace Begins Here! 44

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