Geriatric anesth cardiac changes
Pretest
Question 1
True or false
Age-related changes of Cardiovascular function include
1. decreased cardiac output and stroke volume,
2. reduced arterial elasticity and peripheral sclerosis,
3.decreased size of sinoatrial and atrioventricular nodes, and
4.sclerosis of the coronary arteries.
Keyword
Cardiovascular function declines with age, compromising the system's ability to tolerate and buffer insults.
Normal age-related changes cause the heart to become a less effective pump for the body, which results in elderly patients' decreased ability to respond to autonomic stimulation and stressors such as surgery.
Physiologic changes in the cardiovascular system are related directly to stiffening and decreased distensibility of systemic arteries and the cardiac wall.
Age-related changes include
* decreased cardiac output and stroke volume,
* reduced arterial elasticity and peripheral sclerosis,
* decreased size of sinoatrial and atrioventricular nodes, and
* sclerosis of the coronary arteries.
According to most sources, after 30 years of age, an individual's cardiac output declines about 1% per year.
As a result of decreased cardiac output, elderly patients experience delays in medication absorption, onset of medication action, and medication elimination.
Of particular importance to perioperative team members is the delay in IV medication action in elderly patients.
Reduction in arterial compliance or elasticity as a result of media fibrosis is considered a normal age-related change, as is peripheral blood vessel sclerosis.
Decreased elasticity of vessels results in increased peripheral vascular resistance, elevation of systolic blood pressure, and hypertrophy of the left ventricle.
Elderly individuals with peripheral vascular disease also may have blood pressure discrepancies between their arms.
Sclerosis of the cardiac conduction system and decreased sinoatrial and atrioventricular node sizes increase the occurrence of conduction delays and susceptibility to arrhythmias.
Damage to the conduction system may be due to previous ischemic episodes resulting from sclerosis of the coronary arteries.
Other changes associated with arteriosclerosis of the conduction system include
* reduced resting heart rate,
* prolonged PR interval,
* "sick sinus syndrome" (ie, chaotic atrial activity characterized by continual P-wave configuration changes and bradycardia alternating with recurring ectopic beats and runs of supraventricular tachycardia), and
* blunting of tachycardia responses to hypoxia and hypercapnia.
As postural hypotension is common in elderly individuals, these patients should be observed closely during position changes (eg, ambulating to the bathroom in the preoperative holding area, sitting up for transfer from the transport stretcher to the OR bed). Elderly patients also may exhibit exaggerated decreases in blood pressures during the induction of general anesthesia as a result of diminished cardiac reserves.
Older patients have increased susceptibility to heart failure after parenteral fluid therapy.
Decreasing the workload of elderly patients' hearts and providing oxygen support as needed are vital interventions. Elderly patients must remain connected to cardiac monitors throughout their perioperative care.
Under normal circumstances, elderly patients' hearts maintain adequate function. During stressful events, however, their hearts may not respond effectively or in a timely manner.
Interventions to decrease cardiac workload and ensure therapeutic medication dosing help promote positive outcomes in elderly surgical patients.
From http://www.encyclopedia.com/doc/1G1-19267944.html
Post test
Question 1
True or false
Age-related changes of Cardiovascular function include
1. decreased cardiac output and stroke volume,
2. reduced arterial elasticity and peripheral sclerosis,
3.decreased size of sinoatrial and atrioventricular nodes, and
4.sclerosis of the coronary arteries.
Answer:
TTTT