Special Populations Flashcards
Which patient population has less organ reserve?
Geriatric population
What does having less organ reserve mean?
diminished function, may be smaller (liver, brain)
Patients over 70 take how many prescription medications daily?
two
19% taking more than 10!
Why are geriatrics more prone to adverse reactions to medications?
Polypharmacy
Physiologic considerations for geriatrics
Volume dependent LV hypertrophy = increased LVEDP Endogenously beta-blocked = decreased HR Hypotensive Lungs stiffer = gas exchange not as efficient slower circulation time
Pharmacokinetic changes in geriatrics
decreased total body water decreased lean body mass more body fat decreased serum albumin decreased kidney weight/function decreased hepatic blood flow
What is another protein that drugs bind to besides albumin?
alpha 1 glycoprotein
not usually a big impact however
Anesthetic considerations for the elderly
meticulous preoperative assessment (activity level)
cautious titration of drug administration and dosages
decreased MAC requirements
Sensitivity to opioids in the aging population may be a result from
declining neuronal function
may need additional monitoring such as BIS monitor
plasma drug concentrations immediately after inject are usually ____ in the elderly
higher
regional anesthesia geriatric considerations
anatomic changes in epidural and subarachnoid space
diameter and number of myelinated fibers is decreased
increased permeability of the dura and decreased volume of CSF
occlusion of intervertebral foramina with fibrous connective tissue
muscle relaxant considerations for the elderly
reduced skeletal muscle mass
delayed onset of action
extended duration of action
reduced plasmacholinesterase
What is a common postoperative complication in the elderly?
delirium
Commonly used medications used in the perioperative setting that may induce postoperative delirium
tricyclic antidepressants, antihistamines, antimuscarinics, antispasmodics (scopolamine), antipsychotics, H2 receptor antagonists, skeletal muscle relaxants, antiemetics, corticosteroids, meperidine, benzodiazepines, sedative-hypnotics
Dosing in the obese patients should consider
volume of distribution for loading dose
clearance for maintenance dose
lean body weight
Propofol dosing for obese
LBW for induction
TBW for maintenance
total clearance and Vd correlate well with TBW
Midazolam dosing for obese
TBW for loading dose
IBW for maintenance
sedative effects correlate better to larger Vd and less to elimination
Dexmeditomidine dosing for obese
0.2 mcg/kg/min
lower than usual infusion rates to decrease cardiac S/Es
Succinylcholine dosing for obese
TBW
pseudocholinesterase activity increases with weight
Roc/Vec/Cis dosing for obese
IBW - ensures more predictable recovery
prolonged DOA with TBW administration
Fentanyl dosing for obese
dosing based on TBW overestimates dose requirements
Sufentanil dosing for obese
TBW loading dose
LBW maintenance
increased Vd and prolonged elimination 1/2 life correlates with degree of obesity
Remifentanil dosing for obese
IBW
kinetics not effected by weight
Rectal administration of drugs in pediatrics
slower absorption
used in children under 5 for sedation
Intranasal administration of drugs in pediatrics
faster onset
less offensive
can give Midazolam or Fentanyl
IM administration of drugs in pediatrics
not recommended d/t pain that can last days
may be used in emergency and pain medications
may not have as much muscle decreased blood flow so not sure what effect youll get
Smaller muscle mass and greater fat stores in neonates and infants =
greater blood flow to the central organs, water soluble drugs may require higher doses, and mismatch in tissue types effects durations of actions
GFR at birth
40mL/min
GFR at 1 year of age
100mL/min
Anesthetic considerations for cancer patients
NV, dehydrated, decreased total body water, pulmonary fibrosis/toxicity, heart damage
Cisplastin
use: lung CA, breast CA, bile duct CA, ovarian CA
toxicity: nephrotoxicity, peripheral neuropathy, nerve dysfunction
Methotrexate
use: breast CA, lymphomas, bladder CA
toxicity: myelosuppression w/ neutropenia and thrombocytopenia
Bleomycin
use: Hodkin’s and nonHodkin’s lymphoma
toxicity: pulmonary fibrosis
Doxorubicin
use: lung CA, lymphomas, ovarian CA, thyroid CA
toxicity: cardiotoxicity, myelosuppression
Cetuximab
use: colon CA, GI CA
toxicity: interstitial lung disease
How volatiles, barbs, and ketamine influence cancer cell activity
suppress NK cell activity and promote cancer cell mets
How nitrous oxide influences cancer cell activity
reduces purine and DNA synthesis, suppresses neutrophil chemotaxis, facilitates spread of cancer
How propofol influences cancer cell activity
protective effects - anti-inflammatory effect, inhibition of COX2 and reduction of PGE-2, weak Beta adrenoreceptor binding, enhancement of antitumor immunity, NK function preservation
How opioids influences cancer cell activity
produce cellular and humoral immunosuppression (morphine)
How local anesthetics influences cancer cell activity
reduce metastatic burden
