Cardiopulm Issues Across Lifespan Flashcards
Normal HR for Adult vs Infant
Adult 60-70 BPM, Infant 110-160 BPM
Normal BP for Adult vs Infant
Adult 120/80 Infant 75/50
Normal RR for Adult vs Infant
Adult 12/min infant 30-40/min
Normal Tidal Volume for Adult vs Infant
Adult 500 ml, infant 20 ml
Normal PaO2 for Adult vs Infant
Adult 95mmHg, infant 75-80mmHg
Normal PaCO2 for Adult vs Infant
Adult 40mmHg, infant 33mmHg
Normal pH for Adult vs Infant
Adult 7.40, infant 7.33
What is the equation for HRR?
HRR=
RHR + (50- 85%)(Max HR – RHR)
From childhood to adolescence/ adulthood what happens to VO2max?
Generally VO2max increases through childhood to adulthood.
As people age, what happens to resting HR and maximal HR?
resting HR increases
HR max decreases
What happens to alveoli as people age?
with age the alveoli get larger and fewer in number
From a respiratory viewpoint, what patient population do people start to look like with advanced age?
COPD patients
How does aging affect these respiratory factors?: FEV1, FVC, TLC, vital capacity, functional respiratory capacity, residual volume, DLCO/VA
FEV1 - decreased, FVC - decreased, TLC - unchanged, vital capacity - decreased, functional respiratory capacity - increased, residual volume - increased, DLCO/VA - increased
What happens to elastic recoil of lungs as we age?
Decreases, therefore muscles have to work harder to fully exhale.
Is the work of breathing greater for an older individual compared to a younger individual?
Yes, older individual works harder to breath
What contributes to a decrease in chest wall compliance? (“thoracic rigidity”)
Calcification of intercostal cartilage.
Arthritis of costovertebral joints.
↓ contribution of intercostal muscle to effective ventilation.“thoracic rigidity”
↓ diaphragm strength/ force generation
↓ MIP & ↓ MVV
Age related decline in Type II fibers combined with atrophy
Functional consequences of respiratory changes with aging?
Increased energy expenditure for breathing (O2 cost of breathing; ↑ work of breathing)
Decreased gas exchange efficiency
↑ risk of hypoxemia
Increased ventilation compared to younger at same work loads
? Related to ↑ dead space (VD/ VT)
Altered lung & chest wall mechanics - ↑ stiffness/ ↓ compliance
Altered V/Q relationships
Diminished cough reflex
↓ pulmonary defense
Increased susceptibility to respiratory infections
As we age the arteries become stiffer (less compliant). What happens to the left ventricle in an older person?
becomes thicker b/c of decreased artery compliance and resultant increased after-load.
The 4 determinants of myocardial aging?
preload, afterload, heart rate, contractility
What factors make up TPR (total peripheral resistance)?
pulmonary vascular resistance + systemic vascular resistance
What is more accurate max heart rate estimation for elderly than 220-age?
220-age + 15.
what is the advantage of using the cardiac index?
It normalizes the cardiac output measurement for body size.
What happens with Aging and factors of the cardiac muscle?
↑ LV wall thickness ↓ myocyte # ↑ lipid deposition; ↑ fibrosis & collagen ↓ heart compliance Impact on filling ??? “diastolic dysfunction”
What happens with Aging and factors of the cardiac valves?
↑ thickness & calcification
Alters filling & ejection
Afterload stressor
What happens with Aging and factors of the cardiac conduction system?
↑ atrophy and fibrosis
↓ # of SA node pacemaker cells
↑ risk of dysrhythmia
~ 10% of population >70 y/o have atrial fibrillation
What happens with aging and the vascular system?
Large arteries dilate ↓ dilatation reserve ↑ arterial stiffness (↓ arterial compliance) intima: ↑ heterogeneity of endothelial cell subendothelial wall thickens media: ↑ size of smooth muscle layer ↑calcification & collagen deposition Fragmentation & atrophy of elastin HTN ↑ LV hypertrophy/ heart failure
What happens with aging and the heart rate factors?
resting HR w/o change
↓ maximal HR
HR is ↑ @ submaximal workload (compared to younger)
↑ risk of ECG abnormalities
What happens with aging and the stroke volume factors?
SV tends to ↓ as a function of age
What happens with aging and loading conditions of heart?
preload: ↓ early diastolic filling
↑ atrial contribution
“diastolic dysfunction”
What happens with aging and afterload?
Afterload: ↑ resistance to outflow from LV ↑ BP/ HTN ↑ predominately in SBP related to: ↑ TPR aortic stiffness ↓ peripheral vascular bed may result in ↓ SV & CO ventricular hypertrophy
What are some neurohumoral changes in the heart with aging?
Sympathetic nervous system activity increases
↑ circulating catecholamines
Parasympathetic nervous system activity decreases
↓β- adrenergic responsiveness
Blunted post-synaptic responses
? ↑ α-adrenoreceptor responsiveness
Baroreceptor sensitivity decreases
↑ orthostatic intolerance/ ↑ risk of postural hypotension/ syncope
What cardiac factors have a training response in elderly people?
max HR doesn’t change much. Can increase cardiac output with increase in stroke volume
What factors do we need to change for exercise prescription in Elderly?
↑ warm up time/ ↑ cool down time required
↑ time required to reach physiologic steady state
↓ responsiveness of cardiovascular system
↓ fitness levels
What are benefits of exercise in elderly?
↑ in VO2 max
↑ CO; ↑ SV
Resting CV Function:
? ↓ in resting HR & BP
Submaximal Workloads:
↓ HR & BP @ submax workloads
? ↑ EF/SV
Peripheral changes
↑ (A-V) O2 difference
↑ muscle mass; ↑ capillary density; ↑ aerobic enzymes
