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The Traveller with Chronic Medical Conditions Karen McClean, MD FRCPC University of Saskatchewan.

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Presentation on theme: "The Traveller with Chronic Medical Conditions Karen McClean, MD FRCPC University of Saskatchewan."— Presentation transcript:

1 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

6 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 > 200)

7 Respiratory contraindications Baseline PaO 2 < 70 mmHg at sea level without supplemental O 2 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 >30,000 feet –Cabin pressures: 5, ,000 ft (1,500-2,500 meters) above sea level 35,000 ft: cabin pressure = 5,500 ft above sea level –PO 2 decreases from 159 mmHg to 128 mmHg –P A O 2 decreases from 107 mmHg to 74 mmHg –PaO 2 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 PaO 2 > 60 mmHg: oxygen- hemoglobin dissociation curve is flat and oxygen delivery is unaffected. Once the PaO 2 falls below > 60 mmHg, there is a rapid decrease in oxygen delivery.

13 Hypoxemia & High Altitude Flight

14 Underlying respiratory impairment may lead to reduced PaO 2 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

16 Cardiac Disease

17 Travel issues for cardiac patients Cardiac events: –Most frequent cause of death in adult travellers –Most common cause of inflight death (>50%) –Second most common reason for medical evacuation

18 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

19 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

20 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

21 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

22 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

24 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

25 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. provides list of anticoagulation clinics in other countries – but many countries not representedhttp://www.acforum.org/locations.html

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

27 Malaria prophylaxis Warfarin interactions: increased INR and bleeding risk –Doxycycline –Malarone –Proquanil Digoxin interactions: chloroquine Prolonged QT interval: chloroquine, mefloquine

28 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

29 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

30 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?

31 Respiratory disease

32 Issues for travellers with respiratory disease –Altitude –Air quality –Allergens –Pathogens

33 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

34 Assessing need for oxygen Risk Assessment –minimal risk destination altitude < home altitude able to climb two flights / walk indefinitely on level –increased risk Baseline PaO 2 < 70 mmHg FVC < 50% of expected SaO 2 < 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 –SaO 2 > 95% no oxygen required –SaO % with no risk factors Further investigation required –SaO % with risk factors Oxygen required –SaO 2 < 92% Risk factors: hypercapnia, FEV1 < 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% O 2 ) –Assess: clinical status, ABGs (PaO 2 < 50 mmHg, SaO 2 <85%), ECG changes of ischemia or strain –Imprecise correlation of PaO 2 with actual PaO 2 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

37 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 formula’s have been worked out in COPD patients Predicted in-flight PaO 2 –[0.453 x Ground PaO2] + [0.386 x FEV1%] –[0.410 x Ground PaO2] –Numerous others!

38 What’s 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% –FEV1< 50%:sensitivity = 70%, specificity = 96%

39 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 < 50% predicted –ABGs: PaO 2 < 70 mmHg Traveller with CO 2 retention – consider HIT Collaboration between respirologist and travel medicine specialist

40 Who should be assessed for supplemental Oxygen? Cardiac –Ischemic heart disease –Dilated cardiomyopathy / amiodarone lung –Eisenmenger’s 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

41 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

42 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?

43 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

44 Questions?

45 Diabetes and Travel

46 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)

47 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 (< 1 month ok at RT) –Some types of insulin syringes are not widely available (U100 syringes esp.)

48 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

49 Diabetes management Oral hypoglycemics –No dose adjustment required for travel Insulin: regular / long acting insulin regimens –No dose adjustment if < 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 minutes prior to a meal…delays may result in hypoglycemia)

50 Insulin dose adjustment Rule of thirds: –Travel west:  insulin by 1/3 Day of departure: take usual morning insulin pm insulin hours later Blood sugar 18 hours after morning insulin: if > 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 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

51 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

52 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

53 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

54

55 What’s 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 / β blockers (QT lengthens as HR slows) –QT prolonging drugs, especially concurrent use of multiple drugs that prolong QT –Hypokalemia, hypomagnesemia (diuretics!), hypocalcemia –Hypothyroidism

56 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’

57 QT prolonging drugs Many different drugs and classes represented Useful categorization…. 1.Drugs with risk of TdP Chloroquine, quinine Macrolides (clarithro, erythromycin) 2.Drugs with possible risk of TdP Quinolones, azithromycin, effexor 3.Drugs to be avoided in Congenital LQTS Includes list 1 and 2 drugs plus additional drugs 4.Drugs unlikely to cause TdP if used in absence of other risk factors Ciprofloxacin, azoles, TMP-SMX, celexa, prozac


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