The Traveller with Chronic Medical Conditions

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The Traveller with Chronic Medical Conditions

• Karen McClean, MD FRCPC
• University of Saskatchewan

2
The unwell traveller

• Cardiac disease
• Respiratory disease
• Diabetes
• Renal Failure
• Neurologic disease
• Immune deficiency
• Malignancy
• Chronic connective tissue diseases

3
The unwell traveller general advice

• Medic alert bracelet
• Medications
• dual supply (carry-on and checked luggage)
• list of medications
• generic names
• full dosing information
• indications
• Physician contact information
• Copy of relevant lab data
• 12 lead ECG copy and report
• arterial blood gases
• recent lab results (INR, creatinine etc.)

4
The Unwell Traveller General Advice

• Delay travel until underlying disease is under
  optimal control
• Review contraindications to air travel
• Review altitude risks if appropriate
• Maximize all appropriate prophylactic measures
• Plan ahead
• special meals (diabetic, low salt, low
  cholesterol)
• oxygen
• Contingency plans
• physicians - IAMAT
• insurance and evacuation

5
Medical contraindications for air travel

• Any patient sick enough to have a low probability
  of surviving the flight
• Any serious and acute contagious disease
• Cardiovascular disease
• Respiratory disease
• Neurologic disease
• Post-operative

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Cardiovascular contraindications

• Unstable angina or chest pain at rest
• Recent MI
• Uncomplicated within 2 weeks
• Complicated within 6 weeks
• CABG within past 2 weeks
• Decompensated heart failure
• Uncontrolled arrhythmia
• Uncontrolled hypertension (sys. BP gt 200)

7
Respiratory contraindications

• Baseline PaO2 lt 70 mmHg at sea level without
  supplemental O2
• Pneumothorax within the past 3 weeks
• Large pleural effusion
• Exacerbation of or severe COPD
• Breathlessness at rest

8
Neurologic contraindications

• Stroke within 2 weeks
• Uncontrolled seizures

9
Post-operative / trauma contraindications

• Recent surgery or trauma where trapped air or gas
  may be present
• Abdominal trauma
• Gastro-intestinal surgery
• Craniofacial surgery
• Ocular surgery
• Diving related decompression illness and gas
  embolism (without recompression chamber)

10
High Altitude Flight and Medical Disease
11
High Altitude Flight

• Commercial jet engines operate best at altitudes
  gt30,000 feet
• Cabin pressures 5,000 - 8,000 ft (1,500-2,500
  meters) above sea level
• 35,000 ft cabin pressure 5,500 ft above sea
  level
• PO2 decreases from 159 mmHg to 128 mmHg
• PAO2 decreases from 107 mmHg to 74 mmHg
• PaO2 decreases from 98 mmHg to 65 mmHg
• Saturation for normal individuals 94

12
High Altitude Flight

• In practice, cabin altitudes usually range from
  6,000-9,000 feet, resulting in even greater
  effects on oxygen levels
• As long as the PaO2 gt 60 mmHg oxygen-hemoglobin
  dissociation curve is flat and oxygen delivery is
  unaffected.
• Once the PaO2 falls below gt 60 mmHg, there is a
  rapid decrease in oxygen delivery.

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Hypoxemia High Altitude Flight
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Hypoxemia High Altitude Flight

• Underlying respiratory impairment may lead to
  reduced PaO2 at normal flight altitudes
• Hypoxemia ? tachycardia ? increased oxygen demand
  ? ischemia

15
High Altitude Flight

• Trouble.
• Impaired hemoglobin saturation
• Ventilation problems
• Diffusion capacity problems
• Impaired oxygen delivery
• Anemia
• Impaired tissue perfusion
• Coronary artery disease
• Intestinal ischemia
• Peripheral vascular disease

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Cardiac Disease
17
Travel issues for cardiac patients

• Cardiac events
• Most frequent cause of death in adult travellers
• Most common cause of inflight death (gt50)
• Second most common reason for medical evacuation

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Cardiac Disease and Travel

• Common conditions
• Coronary artery disease
• Congestive heart failure
• Valve replacement
• Atrial fibrillation
• Key concerns
• Altitude effects on O2 supply demand
• Decompensation of CHF or CAD
• Managing anticoagulation
• Drug interactions
• Pacemaker and ICD function / interference

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Supply and demand

• Increased demand
• Physical exertion in transit or at destination ?
  tachycardia
• Psychological stress of travel ? tachycardia
• Acute high altitude exposure? hypoxia induced
  stimulation of sympathetic nervous system,
  tachycardia, hypertension
• Tachycardia increases oxygen demand
• Decreased supply
• Altitude
• Anemia
• Impaired perfusion CAD
• Risks
• Angina, myocardial infarction, arrhythmias

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Assessment History

• Review history of coronary artery disease
• MIs when, severity, complications?
• Revascularization?
• Rehabilitation?
• Current angina triggers?
• Ability to climb 2 flights of stairs without
  difficulty?
• Medications?
• Frequency of rescue nitrate use?
• Arrhythmias?
• Symptoms of heart failure?
• Dyspnea, orthopnea, paroxysmal nocturnal dyspnea,
  poor exercise tolerance, edema

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Interventions

• Refer for formal assessment if concerns
• Difficulty with ADLs
• Frequent use of rescue medication
• Symptoms of CHF
• High risk travel altitude, activities, remote
• Stair climb test
• Stress test no evidence for use
• Assess response to tachycardia

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Recommendations to traveller

• Underlying disease should be optimally controlled
• Review by usual physician to ensure all
  appropriate treatments are being used
• Changing medications immediately before travel
  may jeopardize insurance coverage
• Recent baseline ECG take both paper copy and
  interpretation
• Accurate medication list
• Physician contact information
• Documentation of pacemaker, IAD

23
Anticoagulation

• Valve replacement
• Bioprosthetic valves anticoagulation usually
  discontinued
• Mechanical valves permanent need for
  anticoagulation
• Atrial fibrillation

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The Traveller on Warfarin

• INR will be affected by
• Diet - changing vitamin K intake
• Provide list of moderate to high vitamin K
  content foods
• Exercise and activity level
• Illness
• Drug interactions
• Ascent to high altitude
• Effects usually seen in 3-5 days
• Enhanced monitoring is recommended given
  potential exposures to INR altering influences

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Warfarin monitoring

• Use of INR removes the uncertainties of reporting
  by seconds
• Self monitoring eliminates need for use of local
  facilities but is not common in Canada
• Self monitoring machines are bulky compared to
  glucometers
• Power source issues need to be considered
• Traveller should be stabilized on self monitoring
  and treatment well before travel
• Health providers in other countries may not be
  familiar with warfarin (other agents may be
  standard care), may have difficulty recommending
  appropriate dose adjustments.
• http//www.acforum.org/locations.html provides
  list of anticoagulation clinics in other
  countries but many countries not represented

26
Pacemakers

• Bipolar (modern) pacemakers are not affected by
  electronic interference from aviation industry
  products
• Older unipolar pacemakers may malfunction from
  electronic interference from security devices or
  airplane devices
• IADs hand held security devices may trigger IAD

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Malaria prophylaxis

• Warfarin interactions increased INR and bleeding
  risk
• Doxycycline
• Malarone
• Proquanil
• Digoxin interactions chloroquine
• Prolonged QT interval chloroquine, mefloquine

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How do you decide when you can / should not
recommend CLQ or MFQ?

• Use caution when prescribing drugs that prolong
  the QT interval in the presence of one or more
  risk factors, especially if the individual is
  already on one or more medications that can
  prolong the QT interval.
• Co-administration of Mefloquine with
  cardioactive drugs might contribute to the
  prolongation of QTc intervals, although in the
  light of information currently available,
  co-administration of such drugs is not
  contraindicated but should be monitored.
• Travel Medicine, Schlagenhauf, Beallor, Kain

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When is it OK to use CLQ / MFQ?

• Should chloroquine or mefloquine be prescribed to
  travellers already using QT prolonging drugs?
• Consider options
• Consider risk factors (age, female, bradycardia,
  electrolyte disturbance, structural heart disease
  MI, CHF, LVH)
• The presence of multiple risk factors warrants
  caution
• Avoid in congenital LQTS
• If in doubt
• Screen with ECG
• AV block (any degree)
• Interventricular conduction delay
• Bundle branch block
• Prolonged QT interval
• Consult with cardiologist

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Summary Cardiac disease

• Review travel plans in detail
• destination heat stress, altitude
• access to care
• activities
• living arrangements (?elevators, air
  conditioners)
• Review fitness for travel
• contraindications to air travel
• review ADLs can cardiovascular fitness be
  improved before travel?
• 12 lead ECG conduction abnormalities / LVH
• stress testing - does tachycardia precipitate
  ischemia?

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Respiratory disease
32
Respiratory disease

• Issues for travellers with respiratory disease
• Altitude
• Air quality
• Allergens
• Pathogens

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High Altitude flight and respiratory disease

• Travellers with hypoxic lung disease are at risk
  of symptomatic deteriorations in oxygen delivery
  at altitude
• Emphysema
• Chronic bronchitis
• Interstitial lung disease
• Asthma
• Cystic Fibrosis
• Recurrent pulmonary emboli
• Chronic hypoventilation Obesity hypoventilation
  syndrome, Obstructive sleep apnea, neuromuscular
  disease

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Assessing need for oxygen

• Risk Assessment
• minimal risk
• destination altitude lt home altitude
• able to climb two flights / walk indefinitely on
  level
• increased risk
• Baseline PaO2 lt 70 mmHg
• FVC lt 50 of expected
• SaO2 lt 92 (or 92-95 with risk factors)
• 50 meter walk test inability to complete,
  angina, distress
• Various other predication equations or graphs

35
Oxygen saturation

• Simple, rapid, office based
• Oxygen not required
• SaO2 gt 95 no oxygen required
• SaO2 92-95 with no risk factors
• Further investigation required
• SaO2 92-95 with risk factors
• Oxygen required
• SaO2 lt 92
• Risk factors hypercapnia, FEV1 lt 50, lung
  cancer, restrictive lung disease (chest wall,
  muscle or parenchymal disease), cerebrovascular
  or cardiac disease, within 6 weeks of
  exacerbation of chronic lung disease or cardiac
  disease

36
Predicting hypoxia

• Hypoxia Inhalation testing (HIT)
• Inhalation of hypoxic gas mixture equivalent to
  8,000 ft altitude (15.1 O2)
• Assess clinical status, ABGs (PaO2 lt 50 mmHg,
  SaO2 lt85), ECG changes of ischemia or strain
• Imprecise correlation of PaO2 with actual PaO2
  under hypobaric conditions - not recommended for
  routine use
• When should HIT be done?
• Co-existing conditions adversely by hypoxia
• Symptoms during previous air travel
• Recovering from acute exacerbation of lung
  disease
• Hypercarbia or hypoventilation with oxygen
  administration

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Predicting hypoxia

• Regression Formulae
• Compare a patient with a group of patients with
  similar characteristics who have previously been
  studied under hypoxic conditions
• More physiologic basis than HIT
• Does not permit assessment of individual
  susceptibility to symptoms or ECG changes during
  hypoxia
• Most formulas have been worked out in COPD
  patients
• Predicted in-flight PaO2
• 0.453 x Ground PaO2 0.386 x FEV1 2.44
• 0.410 x Ground PaO2 17.652
• Numerous others!

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Whats the evidence?

• 50 meter walk test not validated in prospective
  studies
• HIT test not validated in prospective studies
• Kids with CF spirometry better predictor than
  HIT
• HIT sensitivity 20, specificity 99
• FEV1lt 50sensitivity 70, specificity 96

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If there is a lack of good evidence, what do we
do?

• Screening tests
• 50 meter walk test
• Oxygen saturation
• Failed screening tests or high risk
• Spirometry FEV1 lt 50 predicted
• ABGs PaO2 lt 70 mmHg
• Traveller with CO2 retention consider HIT
• Collaboration between respirologist and travel
  medicine specialist

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Who should be assessed for supplemental Oxygen?

• Cardiac
• Ischemic heart disease
• Dilated cardiomyopathy / amiodarone lung
• Eisenmengers syndrome
• Congestive heart failure
• Pulmonary
• Severe COPD or Asthma
• Pulmonary fibrosis
• Restrictive lung disease due to chest wall or
  respiratory muscle disease
• Pulmonary hypertension
• Primary
• Secondary (recurrent pulmonary emboli)
• Cystic fibrosis
• Already on home Oxygen

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Supplemental Oxygen

• Requires physician's prescription
• Duration 60 minutes for delays
• Intermittent or continuous use
• Flow rate at 8,000 feet
• Usually 2 litres / minute
• Add 1-3 l/minute for patients already on O2
• Arrangements must be made with each individual
  carrier and for each flight segment
• Costs and required notice differ by carrier
• Check in procedures may change (? time required)
• Personal oxygen delivery devices CANNOT be used
  (portable tanks etc.)
• Oxygen for use during lay-overs and at
  destination
• Must be arranged through commercial oxygen supply
  companies

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Other issues

• Air quality and allergens
• Large urban centers high traffic density
• Industrial air pollutants
• Cigarette smoking
• Low humidity
• Asthmatics and others with reactive airways may
  experience exacerbations from exposure to air
  pollutants and allergens.
• Ensure optimal control before departure
• Monitor peak flows for early warning signs
• Plan for increased use of rescue meds
• Standby steroids?

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Other issues

• Pathogens and the risk of pulmonary infection
• Chronic respiratory disease increases the risk of
  infection
• Use of steroids in treatment for respiratory
  disease may also increase infection risk
• Increased risk of exposure in close quarters
  buses, planes etc
• Exposure to new pathogens lack of prior exposure
  increases risk of infection
• Risk of triggering an exacerbation of underlying
  disease

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Questions?
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Diabetes and Travel
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Diabetes and travel issues

• Diabetic control affected by
• Changing time zones
• Less control over meals timing, food selection,
  availability
• Less control over activity levels
• Acute travel related illness
• Altitude effects on glucometer and insulin pumps
• Older glucometers affected by altitude,
  reportedly less problems with new meters.
• Have alternatives!
• Increased absorption of insulin in hot climates
  (increased blood flow to skin and SC tissues)

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Diabetes and travel issues

• Air travel security insulin pumps, lancets,
  insulin
• Insulin must be in original packing with
  preprinted pharmaceutical label on box
• Glucagon must be in preprinted labelled packaging
• Lancets must be in original packaging and must
  match the glucometer, must be capped
• Physician letter outlining supplies to be carried
• Immigration syringes and needles, drugs
• Physician documentation required
• Access to supplies at destination
• Insulin storage for long trips (lt 1 month ok at
  RT)
• Some types of insulin syringes are not widely
  available (U100 syringes esp.)

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Diabetes and travel issues

• Neuropathy risk of foot injury
• unaccustomed walking, inappropriate footwear
  (sandals, hiking boots, new footwear)
• reinforce need for careful examination of feet
  (daily) and proper foot care
• advise against new footwear for travel should
  be broken in well in advance if needed
• alternate footwear
• frequent changes of socks in hot climates
• standby antibiotic therapy in event of infection
• Retinopathy transient worsening of vision due to
  hypoxic retinal ischemia during high altitude
  flight
• Nephropathy adjust doses of prophylactic or
  standby medications
• increased risk of renal failure if dehydration
  occurs

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Diabetes management

• Oral hypoglycemics
• No dose adjustment required for travel
• Insulin regular / long acting insulin regimens
• No dose adjustment if lt 5 time zone change
• Westward travel longer day requires more insulin
• Eastward travel shortens day, requires less
  insulin
• Insulin basal / immediate acting regimens
• Easier to manage changing time zones
• May be injected immediately prior to a meal
  (Regular insulin needs to be taken 30-45 minutes
  prior to a mealdelays may result in
  hypoglycemia)

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Insulin dose adjustment

• Rule of thirds
• Travel west ? insulin by 1/3
• Day of departure take usual morning insulin
• pm insulin 10-12 hours later
• Blood sugar 18 hours after morning insulin if gt
  13 mmol/l, take 1/3 morning dose snack
• Resume usual doses morning of arrival
• Travel east ? insulin by 1/3
• Day of departure take usual morning insulin
• Evening dose 10-12 hours after am dose
• Day of arrival take 2/3 usual am insulin, BS in
  10 hours
• 2-4 adjustment in insulin dose per time zone

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Standby antibiotics

• Treat travellers diarrhea
• Treat skin and soft tissue infections
• Keflex, erythromycin
• Diabetic foot infections
• Usually polymicrobial
• Clavulin, Cipro flagyl
• Treat vaginal candidiasis
• Fluconazole

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Drug interactions hypoglycemic medications

• Very limited evidence..
• Doxycycline may occasionally potentiate the
  effects of insulin and sulfonylureas
• Chloroquine may improve glucose tolerance in type
  2 diabetics
• No clear evidence for interactions with
  mefloquine
• No indication to avoid any particular
  antimalarial agent but data is limited
  especially for newer drugs
• Increased monitoring of blood sugar

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Diabetes and travel

• Take all required supplies in original packages
• Take extra insulin to allow for problems
• Contingency plans
• Insulin adjustment protocol
• Take an additional supply of regular insulin
• Alternate methods of blood sugar tesing
• Alternate methods of insulin delivery if pump
  used
• Dealing with hypoglycemia
• snacks and sugar supplements
• glucagon
• Be prepared to deal with
• Travellers diarrhea
• Skin and soft tissue infections
• Yeast infections

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Whats the concern?

• Prolonged QT intervals increase the risk of
  polymorphic ventricular tachycardia (Torsade de
  Pointes TdP) and sudden death
• Long QT can be congenital or acquired
• Greatest risk congenital Long QT syndrome
  (LQTS)
• Other risk factors for adverse events
• Female gender (2X increase in risk)
• Increased age
• Structural heart disease (LVH, CHF, MI)
• Bradycardia / ß blockers (QT lengthens as HR
  slows)
• QT prolonging drugs, especially concurrent use of
  multiple drugs that prolong QT
• Hypokalemia, hypomagnesemia (diuretics!),
  hypocalcemia
• Hypothyroidism

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CLQ, MFQ and QT

• Data is sparse!
• Different experts different recommendations!
• Chloroquine
• listed as a drug to avoid in at risk individuals
• isolated case reports usually therapeutic doses
• risk is likely significant with high doses, much
  less or minimal with prophylactic doses
• studies flawed by low numbers, use of healthy
  subjects (not at risk individuals)
• Mefloquine
• does not appear on many of the QT drugs to
  avoid lists
• isolated case reports (esp. co-administration
  with Halofantrine)
• prolongation of QT mild in some studies, none
  in others
• can cause sinus bradycardia
• interaction studies are needed

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QT prolonging drugs

• Many different drugs and classes represented
• Useful categorization.
• Drugs with risk of TdP
• Chloroquine, quinine
• Macrolides (clarithro, erythromycin)
• Drugs with possible risk of TdP
• Quinolones, azithromycin, effexor
• Drugs to be avoided in Congenital LQTS
• Includes list 1 and 2 drugs plus additional drugs
• Drugs unlikely to cause TdP if used in absence of
  other risk factors
• Ciprofloxacin, azoles, TMP-SMX, celexa, prozac
• www.qtdrugs.org/