Transcript Slide 1

CHARALAMPOS KOTSONIS
PEDIATRICIAN-INTENSIVIST
PICU, UNIVERSITY HOSPITAL RIO
Cardio-Circulatory Conditions
 Coronary Heart Disease (CHD)
 Heart Failure
 Arrhythmias
 Congenital Heart Disease
 Pacemaker Function
Cardio-Circulatory Conditions
 Introduction
Analysis of information provided by tourists seeking visas
in Nepal: 20% were 50 years or older
JAMA. 1989;261(7):1017
Austria 1985 – 1991:
416 deaths were sudden (30% of mountain sport related deaths)
Hikers were more than two times as likely as skiers to die
Risks of death: age and lack of prior physical activity
N Engl J Med. 1993;329(23):1738
Cardio-Circulatory Conditions
 Introduction
Prior myocardial infarction (MI) appears to be the greatest
predictor of risk regarding sudden cardiac death (SCD)
among those who downhill ski
Previous MI had a 93 times higher adjusted SCD risk,
(41% vs. 1.5%; p<0.001) when compared to controls
Int J Sports Med. 2000;21(8):613
Cardio-Circulatory Conditions
 Coronary Heart Disease (CHD)
Exercise at altitude in patients with stable coronary heart
disease (CHD) appears to be relatively safe
However, the acute hemodynamic changes associated with
altitude/hypoxemia result in earlier onset of angina symptoms
or ischemic ECG changes (shorter time to symptoms)
Heart. 2006;92(7):921
Am Heart J2010 Jan;159(1):25-32
Cardio-Circulatory Conditions
 Coronary Heart Disease: Undiagnosed CHD
Coronary Occlusion
Holter monitor evaluation was performed in 149 selected
skiers beginning at an altitude of 3430 meters
Only 5.6% of the skiers >40 yrs showed ECG evidence of
ischemia (5% incidence of ischemia noted in screening
stress tests in asymptomatic individuals at sea level)
Arch Intern Med 1990 Jun;150(6):1205-8
Cardio-Circulatory Conditions
 Coronary Heart Disease: Undiagnosed CHD
Plaque Rupture
‘We do not expect that high altitude would have a major
influence’
Regular physical activity has been shown to protect against
plaque rupture
Heart. 2006;92(7):921
Cardio-Circulatory Conditions
 Coronary Heart Disease: Recommendations
Rapid ascent and submaximal exercise can be considered
safe at an altitude of 3454 m for:
Low risk patients
Six months after revascularization for an acute coronary event
and a normal exercise stress test at low altitude
Heart. 2006;92(7):921
Cardio-Circulatory Conditions
 Coronary Heart Disease: Recommendations
Patients at a higher risk may be in danger when exposed to
such an altitude
Evaluate the patient’s functional level, clinical status and
anticipated stress
Heart. 2006;92(7):921
Cardio-Circulatory Conditions
 Coronary Heart Disease: Recommendations
Patients should be warned that anginal symptoms will
probably occur more easily at lower workloads
SOS Strenuous activities should be approached with more
caution, particularly during the first 3 or 4 days at altitude
Heart. 2006;92(7):921
Am Heart J2010 Jan;159(1):25-32
Cardio-Circulatory Conditions
 Heart Failure
Patients with heart failure are especially susceptible to the
physiological changes from high altitude exposure
The pulmonary vasoconstriction and hypertension impairs
right ventricular performance
UpToDate
Am Heart J2010 Jan;159(1):25-32
Cardio-Circulatory Conditions
 Heart Failure: Recommendations
Patient who exhibits symptoms at rest or during minimal
activity, or requires oxygen therapy at rest (NYHA class IV)
Even the stress of air flight may be significant and should
be approached with caution
UpToDate
Cardio-Circulatory Conditions
 Heart Failure: Recommendations
No flying or exposure to altitude for six weeks after an acute
left ventricular failure episode
Patients with only mild functional compromise at sea level
will probably tolerate moderate altitudes
Heart. 2010;96 Suppl 2:ii1
Cardio-Circulatory Conditions
 Heart Failure: Recommendations
Advise patients that they may become symptomatic at lower
exercise workloads at high altitudes (>2500 meters)
Limit activity at moderate or high altitudes to a lower maximal
level than typically performed at sea level (80-90%), especially
true during the first few days at altitude
UpToDate
Cardio-Circulatory Conditions
 Arrhythmias
Patients with Underlying Heart Disease
Heightened sympathetic activity associated with high
altitude may increase the frequency and duration of
supraventricular and ventricular arrhythmias
UpToDate
Cardio-Circulatory Conditions
 Arrhythmias
Healthy Elderly Men (Age 49-69 years)
The incidence of both supraventricular and ventricular
premature beats (VPBs) was nearly doubled at an altitude
of 1350 m (4428 feet) as compared to 200 m (656 feet)
At higher altitude (2632 m), the frequency of ectopy was
increased six- to sevenfold
Physiol Res. 2000;49(2):285
Cardio-Circulatory Conditions
 Arrhythmias
Patients with Stable CHD
VPBs were significantly increased with acute exposure, but
returned to sea level values after acclimatization
Circulation. 1997;96(4):1224
Cardio-Circulatory Conditions
 Arrhythmias: Recommendations
It appears that altitude can aggravate arrhythmias
The patient should be warned to keep activities less than
their sea level baseline (80-90%), particularly during the
first five days at altitude
Deaths at high altitude are often sudden and the contribution
of arrhythmias is unknown
UpToDate
Cardio-Circulatory Conditions
 Congenital Heart Disease: Non Cyanotic
Intracardiac or extracardiac shunts with a net shunting of
blood from the left to the right
However, with exposure to high altitude/hypobaric hypoxia,
pulmonary vascular resistance and right-sided pressures are
increased resulting in a reverse of the shunt, leading to arterial
oxygen desaturation
UpToDate
Cardio-Circulatory Conditions
 Congenital Heart Disease: Non Cyanotic
Patent Foramen Ovale (PFO)
Was roughly 4 times more frequent in HAPE-susceptible
mountaineers than in participants resistant to this condition
HAPE-susceptible participants with a large PFO had more
severe hypoxemia
JAMA. 2006;296(24):2954
Cardio-Circulatory Conditions
 Congenital Heart Disease: Cyanotic
Exposure to moderate altitude (1,500 to 2,500m) has been
reported to be safe
Commercial air travel do not appear to be detrimental
Circulation. 1996;93(2):272
Cardio-Circulatory Conditions
 Congenital Heart Disease: Recommendations
Advice must be individualized and based upon the nature
of the congenital defect and expected stresses
Consultation with a pediatric or adult cardiologist specializing
in congenital defects should precede altitude exposure
Circulation. 1996;93(2):272
Am Heart J2010 Jan;159(1):25-32
Cardio-Circulatory Conditions
 Pacemaker Function
Inhalation of 10% O2, produced a significant but reversible
increase in stimulation thresholds
Hypocapnia, induced by mechanic hyperventilation, led to
a reduction in pacing stimulation thresholds
Scand J Thorac Cardiovasc Surg Suppl. 1971;8:1
Cardio-Circulatory Conditions
 Pacemaker Function
Stepwise simulated hypobaric chamber ascent from
450 meters to 4000 meters (1476-13120 feet) produced
NO change in stimulation threshold
Pacing Clin Electrophysiol. 2000;23(4 Pt 1):512
Cardio-Circulatory Conditions
 Pacemaker Function: Recommendations
Pacing thresholds can be expected to remain unchanged at the
moderate altitudes seen with air travel and recreational skiing
The safety of pacemakers at the extreme altitudes, as with
trekking and mountaineering, is not known
UpToDate
Cardio-Circulatory Conditions
 Implantable Cardioverter-Defibrillators (ICD)
Effects of altitude on implantable cardioverter-defibrillators
are unknown at this time
Am Heart J2010 Jan;159(1):25-32
Cardio-Circulatory Conditions
 Heart Transplant Patients
Patients living >2000 ft have improved survival after heart
transplantation
This advantage is even more pronounced in patients living
above 4000 ft
Analysis still seems to lack a unifying explanation
J Thorac Cardiovasc Surg 2012;143:735-41
Cardio-Circulatory Conditions
 General Recommendations
If unsure of a patient's cardiac status, in any male or female
>40 years, consider performing an exercise treadmill stress
test before planned activity at high altitude
Am Heart J2010 Jan;159(1):25-32
Cardio-Circulatory Conditions
 General Recommendations
Patients with recent unstable cardiovascular conditions
should be directed to refrain from altitude exposure
Stable patients who exercise at sea level without symptoms
can generally exercise at altitude
Am Heart J2010 Jan;159(1):25-32
Respiratory Conditions
 Asthma
 COPD
 Pulmonary Hypertensive Disorders
Respiratory Conditions
 Asthma And High Altitude
Positive Aspects
House-dust mites decrease with increasing altitude
Less dense gases have better flow through narrow airways
Higher levels of cortisol and catecholamines at altitude may
play a protective role
Eur Respir J 2007; 29: 770–792
Respiratory Conditions
 Asthma And High Altitude
Negative Aspects
Hypoxia increases bronchial responsiveness
Hypocapnia adversely affect airway resistance
Inhalation of cold air may also worsen asthma symptoms
Eur Respir J 2007; 29: 770–792
Respiratory Conditions
 Asthma And High Altitude: Recommendations
Patients with mild-intermittent or mild-persistent asthma
can ascend to altitudes as high as 5,000 m
Continue baseline medications and carry an ample supply
of rescue inhalers and prednisone for potential exacerbations
Consider using balaclava or bandana over mouth to warm and
humidify air in cold environments
Eur Respir J 2007; 29: 770–792
Respiratory Conditions
 Asthma And High Altitude: Recommendations
Patients with more severe disease at baseline should be
cautioned against travelling to remote high-altitude regions
In general, asthmatics appear to have NO higher risk of
high altitude illness than non-asthmatics
Eur Respir J 2007; 29: 770–792
Respiratory Conditions
 Chronic Obstructive Pulmonary Disease
Physiological Problems of COPD
Gas-exchange inefficiency
Increased ventilatory requirements
Reduced muscle strength
Mild–moderate pulmonary hypertension
Eur Respir J 2007; 29: 770–792
Respiratory Conditions
 Chronic Obstructive Pulmonary Disease:
Recommendations
Counsel patients with pre-existing pulmonary hypertension
against high-altitude travel
Continue baseline medications and carry supply of rescue
inhalers and prednisone for potential exacerbations
Eur Respir J 2007; 29: 770–792
Respiratory Conditions
 Pulmonary Hypertensive Disorders:
Recommendations
Counsel patients against high-altitude travel
If high-altitude travel cannot be avoided, counsel patients
about the risks, symptoms and signs of HAPE
Eur Respir J 2007; 29: 770–792
Respiratory Conditions
 Pulmonary Hypertensive Disorders:
Recommendations
Administer supplemental oxygen for trips above 2000 m
even in patients not on supplemental oxygen at baseline
For patients not on pre-existing medical therapy, prophylaxis
with Nifedipine SR 20 mg b.i.d is recommended
Eur Respir J 2007; 29: 770–792
Metabolic Conditions
 Diabetes Mellitus (DM) And High Altitude
Glucose monitors may under or over read at altitude
Insulin must not be allowed to freeze or go too hot
Insulin and some test devices are also sensitive to UV
UIAA GUIDELINES
Metabolic Conditions
 Diabetes Mellitus (DM) And High Altitude
Type II DM: Should have no problems with altitude, once their
disease is well controlled and no severe complications have
occurred
Type I DM: can tolerate even vigorous exercise, including
participation in competitive triathlons
UpToDate
Hematologic Conditions
 Sickle Cell Disease
Sickle cell crisis can occur at altitudes as low as 1500m (4900 ft)
Symptoms are common at 2300 m (7500 ft)
Patients with sickle cell trait may become symptomatic from
splenic sequestration or infarct at altitudes >2500 m (8000 ft)
UpToDate
Pediatric Mountaineering
 Physiology
Certain anatomic and physiologic factors make infants and
young children more susceptible to hypoxia than adults
This susceptibility may be translated into a greater frequency
of HAI at very high altitudes (>3500 m [11,375 ft])
However, most healthy children can travel safely to altitudes
lower than 3500 m and are not at greater risk than adults
UpToDate
Pediatric Mountaineering
 Diagnosis of AMS in Preverbal Children
Children's Lake Louise Acute Mountain Sickness Scoring System:
Pediatric Symptom Score
Eating
0 – Normal
1 – Slightly less than normal
2 – Much less than normal
3 – Vomiting or No eating
Playfulness
0- Normal
1 – Playing slightly less
2 – Playing much less than normal
3 – No playing
Sleeping
0 – Normal
1 – Sleeps slightly less or more than normal
2 – Sleeps much less or more than normal
3 – not able to sleep
Arch Pediatr Adolesc Med 1998; 152:683
Pediatric Mountaineering
 Diagnosis of AMS in Preverbal Children
Arch Pediatr Adolesc Med 1998; 152:683
Pediatric Mountaineering
 Diagnosis of AMS in Preverbal Children
Children were scored by combining the mean fussiness
score (0-6) with the pediatric symptom score (0-9)
Total score 7 (including a fussiness score 4 and pediatric
symptom score 3) is considered to be diagnostic of acute
mountain sickness
Arch Pediatr Adolesc Med 1998; 152:683
Pediatric Mountaineering
 Special Considerations
The use of Nifedipine for prevention of HAPE in children has
not been studied
Acetazolamide prophylaxis is indicated in situations where
gradual ascent is not possible and in children who have had
AMS when previously exposed to a similar altitude and rate
of ascent
UpToDate
Conclusions
 Individualize Medical Advise Upon:
Specific medical condition and demographic features
Baseline functional capacity
Expected altitude that will be encountered
Anticipated activity level while at altitude
UpToDate
Conclusions
 General Recommendations
SOS
Keep a lower threshold for evacuation to a lower altitude
as regards patients with pre-existing medical
conditions and children
UpToDate
Safety First
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Κοτρωνάρος Παναγιώτης