ITE Gen Clin Sciences Flashcards
Medically direct vs Medically supervised billing
Medically direct:
- preop exam
- induction and emergence
- monitor course
- physically present and available for immediate needs
- Doesn’t need to be the same physician
Medically supervised: lower pay
Doubling the distance from a radiation source decreases exposure to ____ of the original
1/4
Intensity = 1/(r^2)
Why does nitrous oxide accumulate in closed spaces?
It is 30x more soluble than nitrogen.
Nitrous oxide will leave the blood, entering closed space much faster than nitrogen can leave that closed space back to the blood.
What is most rapidly expanded if nitrous oxide is used,
- tension pneumothorax
- expansion of venous air emboli
- penumocephalus
- intravitreal gas bubbles
pneumothorax
- can double in 10 minutes
Why is use of nitrous oxide in pts with intestinal obstruction avoided?
risk of expansion of air in lumen and w/in bowel
- expansion of mucosa -> ischemia/infarcation
- intestinal rupture
- unable to close abdomen
What is more sensitive to detect VAE, Precordial doppler or PAC? What are its limitations?
Precordial doppler
- difficult in obese pts
_______ drugs cause extrapyramidal symptoms, especially in chronic, high doses, or simultaneous fashion. It can be treated with _______ meds.
Antidopaminergic drugs
Anticholinergic
- benztropine
- diphenhydramine
- atropine
Latex allergies results in the development of _____ antibodies against _____. People with fruit allergies often have _____.
IgE antibodies
Latex antigens
Antibodies that cross-react with latex
Carbon monoxide poisoning shifts the hgb-oxygen dissociation curve to the (right/left).
Left
- inhibits oxygen unloading from blood to tissues.
- hgb binds CO with a 200x affinity than O2
Hyperbaric oxygen therapy is reserved for pts with ___ (4)
- neuro involvement
- cardiac abnormalities
- HbCO > 25%
- Pregnancy
____ in the best indicator of liver transplant graft function
INR
- elevated = good liver func
Other nonspecific liver labs: AST: muscle injury Albumin: poor nutrition Bilirubin: GI bleeding or hemolysis GGT or Alk phos: biliary issues
Lung volume at which small airways begin to close
closing capacity
When closing capacity surpasses FRC, ____ increases and _____ decreases
shunt
oxygenation
The ____ score replaced the _____ score for prioritization of pts for liver transplant
MELD
Child-Pugh
Mneumonic for MELD scoring for liver transplant
I Crush Several Beers Daily
- INR
- Cr
- Sodium
- Bilirubin
- Dialysis
neuroleptic malignant syndrome occurs in pts taking _____.
antipsychotics
- 1st gen: haloperidol
- New atypical
Implications of decreased beta-receptor responsiveness in elderly patients
Limited compensatory response to stress
- If pt becomes hypotensive, they can no longer increase chronotropy, inotropy, and SVR
Ach release is (increased/decreased) with age in response to vagal stimulation
decreased
- decreased parasympathetic nervous system activity
Intercostobrachial nerve arises from ___ nerve root and supplies _______.
It is not blocked by any of the brachial plexus nerve blocks (supraclav, infraclav, interscalene, axillary n)
T2
Medial/posterior upper arm
_______ nerve is a branch of the musculocutaneous n, and provides innervation to the lateral half of the forearm.
Lateral antebrachial cutaneous
- C5-C6 nerve root
_______ nerve is a branch of the musculocutaneous n, and provides innervation to the medial half of the forearm.
medial antebrachial cutaneous n.
- C8-T1
_______ nerve provides innervation to the medial half of the hand
Ulnar
- C8-T1
_______ nerve provides innervation to the medial half of the hand
Median
- C5-C8
______ is the most common cause of an acute change in peak airway pressures and desaturation when a bronchial blocker is used for one-lung ventilation
Dislodgement of the bronchial blocker
When is Bronchospasm (inc peak airway P and desat) most typical?
During induction and emergence
How does a tension pneumo look in the OR?
Hypotension
Desaturation
Gradual inc in peak airway pressures
What is MH and Why are calcium channel blockers contraindicated in malignant hyperthermia when being treated by dantrolene?
MH: Ryanodine receptor defect - prolonged opening of channel - hypermetabolic state
Dantrolene has synergistic effect with CCB and decreases release of calcium from SR ->
- Arrhythmias
- Myocardial depression
- HyperK
- CV collapse
Each 20mg vial of dantrolene contains ___ g of mannitol
3g
- helps maintain u/o
Meralgia paresthetica is ____ and is d/t compression/stretch injury of the nerve as it passes around the anterior superior iliac spine through the inguinal ligament
a mononeuropathy of the lateral femoral cutaneous nerve
- pure sensory
*common in pregnancy
Brachial plexus injury can occur in open heart surgery (sternotomy) secondary to _____
sternal retractor use
Meperidine’s active metabolite is normeperidine, which is excreted by the kidneys. Accumulation of it is ______
neurotoxic and can cause seizures
*caution in pts with renal dysfunction
Morphine’s active metabolite is morphine-6-glucuronide, which is excreted by the kidneys. Accumulation of it is ___
known to cause sig respiratory depression
*caution in pts with renal dysfunction
Why does meperidine often have tachycardia as a common side effect?
molecule resembles atropine
Glycopyrrolate is an _____ drug that works mainly at ____ receptors.
Anticholinergic
- competitive antagonist of acetylcholine
- blocks parasympathetic effects of cholinergic surg
Muscarinic
What happens if you block muscarinic receptors on the heart?
Receptors loc at SA node
-> block = tachycardia
*Glycopyrrolate and atropine and Scopolamine is an anticholinergic
What happens if you block muscarinic receptors on the airway mucosa and bronchi?
Inhibits salivation and respiratory secretion
Also leads to bronchial muscle relaxation
*Glycopyrrolate and atropine is an anticholinergic
What happens if you block muscarinic receptors on the GI system?
decrease gastric motility and peristalsis -> constipation
*Glycopyrrolate and atropine is an anticholinergic
What happens if you block muscarinic receptors on the GU system?
Urinary retention
*Glycopyrrolate and atropine is an anticholinergic
What happens if you block muscarinic receptors on the Ophthalmic system?
pupillary dilation and photophobia
*Glycopyrrolate and atropine is an anticholinergic
What happens if you block muscarinic receptors on the neurologic system?
Glycopyrrolate does NOT cross BBB: no effect
Atropine and scopolamine: AMS and hallucinations