Geriatrics Flashcards
How does aging effect each of the following: Lean body mass (muscle mass)? Fat accumulation? Metabolic rate? Total Body Water? Blood Volume?
Lean body mass is decreased Increased total body fat Decreased metabolic rate Decreased total body water Reduction in blood volume
Why does it take less drug and more time for induction in the geriatric population?
The contracted blood volume makes plasma concentrations higher. Geriatric patients have a decreased circulation time.
Why is thermoregulation of concern in the geriatric patient? What are methods to help ensure normothermia?
The elderly have less lean muscle, less TBW, decreased ability to vasoconstrict and regulate heat, decreased metabolic rate, and decreased function of the hypothalamus for regulating temperature.
Preoperative warming and intraoperative warming are important. Using heated fluids will also help.
Regarding the cardiovascular system of the geriatric speak to the following: amount of circulating catecholamines? End organ responsiveness to catecholamines? Circulation time (inhalation induction and IV induction)? Baroreceptor sensitivity? Heart remodeling?
Amount of circulating catecholamines is increased, but organ responsiveness is decreased.
Circulation time is increased (hastens inhalation induction and slows IV induction)
Baroreceptor sensitivity is decreased and hypotension is more common
Heart is often faced with concentric changes due to increased SVR and thus hypertrophy develops
What is a MET? What is the significants of the MET in the elderly? What value is associated with a significant decrease in perioperative cardiac complications?
A MET is a metabolic equivalent; it corresponds to the amount of oxygen consumed by a 70 kg patient at rest. If a patient has > 4 METS it is associated with good cardiovascular health for general anesthesia and surgery. > 4 METS is the equivalent of walking a block or a flight of stairs without having to stop.
What causes each of the following in the elderly and what is the resulting consequence: Myocardial hypertrophy, Reduced Ventricular Filling, Reduced Beta Receptor Responsivness, Conduction Abnormalities, Stiff Arteries, Stiff Veins
Myocardial Hypertrophy: concentric pressure from increased SVR / can lead to low CO
Reduced LV Relaxation: impaired calcium homeostasis / diastolic dysfunction - poor filling
Reduced Beta Response: decreased density and responsiveness / poor compensation
Conduction Abnormalities: stress on conduction system / reduced LV filling
Stiff Arteries: loss of elastin / hypertension, poor volume compensation, hypertrophy of LV
Stiff Veins: loss of elastin / inability to buffer volume changes to heart —> CHF
How is the volume of distribution of lipophilic and hydrophilic drugs effected in the elderly? What does this say about the plasma concentration of the drug?
Lipophilic drugs v/d is increased reducing the plasma concentration
Hydrophilic drugs v/d is decreased increasing the plasma concentration
