3. Hematologic requirements
“blood must carry sufficient oxygen to satisfy metabolic
requirements at rest, during exertion and anxiety, both at
ground level and at altitude.”
Hb < 10.5 - 11 g/L should be considered as unfit.
Hemoglobinopathic trait or thalassemia minor is
genera%y acceptable.
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
4. Common condition
G-6-PD deficiency Hemoglobinopathy
Polycythemia vera
Acute leukemia
Chronic leukemia
Lymphoma
Bleeding diathesis
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
5. Common condition
G-6-PD deficiency Hemoglobinopathy
Polycythemia vera
Acute leukemia
Chronic leukemia
Lymphoma
Bleeding diathesis
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
7. Approach to anemia
History
Family history of anemia
On set: acute vs chronic
Physical exam
Pa%or
Liver and spleen
8. Key point
Family Hx su'ests congenital disease e.g. thalassemia
Acute onset su'ests blood loss or hemolysis e.g. G-6-PD
deficiency, AIHA, UGIB
Chronic onset usua%y causes no symptom and more likely
due to decrease production
Liver and spleen also su'est thalassemia or hereditary
spherocytosis
11. Key point
Hct > Hb x 3 : su'ests hemoglobin H disease
MVC < 80 : su'ests iron def. of thalassemia
RDW > 12 : su'ests anisocytosis
Normal RDW could be thalassemia trait of ACD
MCHC > 34 g/dL su'ests hereditary spherocytosis
PMN predomination reflects normal marrow function
12. G-6-PD deficiency
X-linked recessive inherited
Send for G-6-PD level to make diagnosis
May considered as fit to fly if can avoid food or
medication that cause hemolysis
Fava
Sulfa
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
13. Polycythemia vera
Hb > 18.5 g/dL in male or > 16.5 g/dL in female
Presence of JAK2V617F or Jak2 exon 12 mutation
Panmyelosis marrow with prominent erythroid,
granulocytic and megakaryocytic proliferation
Low EPO level
Endogenous erythroid colony formation in vitro
Swerdlow SH, et al, ed. WHO classification of tumours of haematopoietic and lymphoid tissues. 4th ed. 2008.
14. Polycythemia vera
Genera%y considered as unfit due to risk of
thromboembolic episode
May considered a restricted certification if we% control
by blood letting, aspirin, and hydroxyurea
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
15. Acute leukemia
Why do you ask?
Event cured case sti% has a risk of late complication of
chemotherapy and radiation
Cataract
Pulmonary fibrosis
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
16. Chronic leukemia
CML may be considered restricted certification
CLL may be assessed as fit as long as they remain
asymptomatic
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
17. Lymphoma
If cured, restricted certification may be issued a*er two
years a*er treatment
Hodgkin lymphoma, diffuse large B-ce% lymphoma, etc.
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
18. Bleeding disorder
Platelets < 75,000/mcL is disqualified
ITP in remission a*er 6 months of treatment is
acceptable
Moderate to severe hemophilia or other congenital
bleeding disorder is disqualified
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
19. Thromboembolism
Pulmonary embolism required 6 months of treatment
before reconsideration as fit
Recurrent pulmonary embolism is considered as unfit
History of deep vein thrombosis require fu%
investigation for underlying cause before consideration
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
20. Anticoagulant & antiplatelet
W arfarin or coumarin use is incompatible with
certification
Low dose low molecular weight heparin may be
acceptable (e.g. enoxaparin 40 mg OD)
Aspirin in low dose is acceptable but clopidogrel or other
more potent antiplatelet a bar to flying
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
21. Hemoglobinopathy
A% trait is acceptable for certification
Sickle ce% disease in any form is disqualified
Thalassemia disease is usua%y disqualified due to low
hemoglobin level
Manual of cicil aviation medicine. 3rd ed. ICAO. 2012.
23. Hematologic physiology
G Y
LO
TO R!!
A E
EM PT
H A
N O CH
Davis JR, ed. Fundamentals of aerospace medicine 4th ed. LippincottWi%iams&Wilkins. 2008.
24. Hemoglobin & hypoxia
Oxygen-carrying capacity(mL O2/100 mL)
= (1.34 x Hb x SaO2) + (PaO2 x 0.0031)
Norma%y 20 ml O2/100 ml blood
Davis JR, ed. Fundamentals of aerospace medicine 4th ed. LippincottWi%iams&Wilkins. 2008.
25. Hemoglobin & hypoxia
O2 carrying capacity(mL O2/100 mL)
= (1.34 x Hb x SaO2) + (PaO2 x 0.0031)
Norma%y 20 ml O2/100 ml blood (at Hb 15 g/dL)
If Hb 7 g/dL O2 carrying capacity is only 9.8 ml O2/100
ml blood
Davis JR, ed. Fundamentals of aerospace medicine 4th ed. LippincottWi%iams&Wilkins. 2008.
26. What can we do??
Raise Hb level
Raise PaO2 level
Davis JR, ed. Fundamentals of aerospace medicine 4th ed. LippincottWi%iams&Wilkins. 2008.
27. Preparing
Hb < 7 g/dL should be contraindicated to fly
Transfusion to keep Hb > 10 g/dL before flight
If transfusion is not available altitude restriction is
mandatory
O2 supplement to keep O2Sat > 90% is helpful in most
patients with mild anemia or cardiac disease
Davis JR, ed. Fundamentals of aerospace medicine 4th ed. LippincottWi%iams&Wilkins. 2008.
28. Sickle cell disease
Sickle ce% crisis occur at desaturation
Threshold is PaO2 < 60 mmHg (alt. 10,000 feet)
Most commercial flights are pressurized to 8,000 feet
But if patient with underlying pulmonary disease may
desaturate at 4000 feet
Genera%y O2 supplement is recommended for a% patients
Davis JR, ed. Fundamentals of aerospace medicine 4th ed. LippincottWi%iams&Wilkins. 2008.
29. Bleeding diathesis
Aspirin usua%y does not cause bleeding problem
Platelet below 50,000/mcL should be transfused before
flight
Coagulogram more than 1.5 time of control should be
corrected before flight
30. In flight DVT prevention
avoidance of constrictive
clothing around the lower
extremities or waist
maintenance of adequate
hydration
.equent calf muscle
contraction
Hirsh j, et al. ACCP evidence-based clinical practice guidelines 8th ed. Chest 2008;133;71-109.
31. Thromboembolism
Hx of DVT or high risk of DVT should be prophylaxis
with below-knee graduated compression stocking or low
molecular weight heparin during a long-haul flight*
Un.actionated heparin can be used to treat
thromboembolism patient with monitoring before and
during flight
Protamine can be used to neutralized heparin if bleeding
*Hirsh j, et al. ACCP evidence-based clinical practice guidelines 8th ed. Chest 2008;133;71-109.
32. Dose of protamine
Protamine 1 mg for 100 units of accumulated heparin
Accumulated heparin = 2 x rate
Anaphylactic reaction can occur with protamine
34. For airman
Acceptable Hb is not less than 10 - 15 g/dL
Most hematologic diseases are disqualified
Hemoglobinopathy trait is not a disease
Only low dose aspirin is acceptable
35. For evacuation
Keep Hb > 10 g/dL, Plt > 50,000/mcL, coagulogram < 1.5
times of normal range
O2 supplement for mild anemia or high risk for ischemia
Altitude restriction if transfusion is unavailable
DVT prophylaxis measure for long-haul flight