ITE Gen Clin Sciences 2 Flashcards
Inheritance pattern of Malignant Hyperthermia
Autosomal dominant with variable penetrance
MH is a (heterogeneous/homogenous) disorder
heterogeneous
- more than 1 gene defect is responsible for expression of disease
Two receptors involved in MH
RYR1 gene - ryanodine receptor
VG calcium channel
In cardiac surgery, when is awareness/recall most likely?
During rewarming and departure from CPB.
- Anesthetic requirement is higher
- MAC > 0.7 can help
Benefits of double lumen tube > bronchial blocker
- More reliable lung isolation
2. selective lobar collapse
Benefits of bronchial blocker > double lumen tube
- Smaller
- better for pts with trachs or oral/neck sx
- children < 12 - Does not require Endotracheal tube exchange (like DLT)
Benefits of airway exchange catheter > gum elastic bougies?
- Ability to jet ventilate
2. ETCO2 monitoring
Why are diuretics (furosemide) d/c in preop period?
- Hypokalemia
- Blood loss/fluid shifts -> worsen hypokalemia
- Predispose to arrhythmias
*ACE-i and ARBs are also often stopped
What BP meds should NOT be stopped in periop period?
BB
CCB
alpha - 2 agonists (clonidine)
(Barium hydroxide / Soda lime) produces more carbon monoxide and more Compound A d/t decreased water content in the absorbents
Barium hydroxide
Soda lime is made of ____
80% calcium hydroxide
15% water
4% sodium hydroxide
Only medication preventing aspiration pneumonitis when given immediately prior to anesthesia
Sodium citrate
Medications used perioperatively for pts high risk of aspiration
- Sodium citrate
- immediately b4 - H2-blockers
- 1 - 2 hrs b4 - Metoclopramide
Anthrax treatment
Ciprofloxacin
or
Doxycycline
Anthrax clinical course
1-7 days incubation - asymptomatic
Nonspecific influenza-like sx
Gets better, but then gets worse again
- CP
- Cyanosis
- Dyspea
- Hemoptysis
- Necrotizing hemorrhagic mediastinitis
Drugs dosed on ideal body weight
Vecuronium
Rocuronium
Cisatracurium
Drugs dosed on total body weight
Succinylcholine
Propofol MAINTENANCE not induction (LWB)
Maximum lidocaine dosing
55mg/kg
When is LAST (neurologic decline and hemodynamic instability) most likely to occur perioperatively?
10-16 hours after a procedure when [ ] of local anesthetic peaks
Largest # of closed claims for death and brain damage?
- Cardiovascular events
- PE, Stroke, MI, Arrythmia - RESPIRATORY EVENTS
- inadequate ventilation
- esophageal intubation
- diff airway - Equipment issues
How does aspirin prevent clots?
permanently inactivates COX enzyme
- short half life 15 min
- long duration of action
What does inhibiting COX do?
conversion of arachidonic acid to prostaglandin
Prostaglandin -> Thromboxane A2, vital for platelet aggregation and vasoconstriction
Platelet life span is _____, and ____% of circulating platelets are replaced daily
5-10 days
20%
What does clopidogrel and prasugrel do?
Platelet receptor inhibitors
- platelet is inactivated for remainder of its lifespan
Pts who had a coronary cath with bare metal stents can stop taking dual antiplatelet therapy when if postponing surgery -> sig morbidity?
1 month
Pts who had a coronary cath with drug eluting stents can stop taking dual antiplatelet therapy when if postponing surgery -> sig morbidity?
3 mo after stent placement
- preferable 6 months
What is dual antiplatelet therapy?
Clopidogrel + ASA
_____ is primarily responsible for increased systemic vascular resistance and MAP during pneumoperitoneum (CO2 Insufflation) for laparoscopic surgery
Increased vasopressin release
- decreased RH filling
- Decreased renal/splanchnic blood flow -> RAAS system activated -> vasopressin response
- CO2 absorption -> sympathetic response
Absolute contraindications to electroconvulsive therapies?
- Pheochromocytoma
- Recent MI
- Recent CVA
- Recent intracranial sx
- Intracranial mass lesion
- Unstable cervical spine
*Cerebral blood flow increases 400% during ECT secondary to increased metabolic rate and BP -> increases ICP
Why does pulmonary edema result in pts with CHF?
Increased hydrostatic pressure and activation of RAAS
Maximum lidocaine dose with and without epinephrine
55 mg/kg max
7mg/kg with epi
Which one provides better intubating conditions during RSI, rocuronium or succinylcholine?
No difference
How is Roc and Suc dosed based on body weight?
Roc - IBW
Suc - TBW
How many working days are residents allowed to take off during their training?
60 days
(12 weeks)
- 4 weeks/year
+ 5 days for scientific meetings
Physiologic changes in CNS that makes geriatric population more sensitive to neuraxial anes?
- Smaller epidural space
- Less myelinated fibers in dorsal and ventral nerve roots
3, More permeability of dura - Less volume of CSF
The solubility of gases in the serum will (increase/decrease) as a pts temperature is decreased.
increase
*when pts temp drops, more gas remains dissolved in serum like CO2 and value is lower on ABG
In hypothermic pts, what type of metabolic derangement will you see?
Hypocapneic respiratory alkalosis
**when pts temp drops, more gas remains dissolved in serum like CO2 and value is lower on ABG
When do you use pH-stat vs Alpha stat?
pH-stat : Pediatrics
Alpha stat : Adult
A standard dose of succinylcholine (1-2mg/kg) will produce a (phase I / Phase II) block, which means _____
Phase I
- sustained depolarizing block
What antagonizes a phase I block, and what augments it?
Nondepolarizing NMB antagonizes it
Depolarizing blockers and cholinesterase inhibitors will augment the block
In Phase I vs Phase II block, Train of four ratio is typically ___
Phase I: > 0.7
Phase II: < 0.3
Pts with pseudocholinesterase deficiency will affect succinylcholine how?
May create a phase II block
- increase DOA by several hours
*Depolarizing blockers and cholinesterase inhibitors will augment the block
Equipment standards for surgical facilities and office practices (5)
- reliable oxygen source
- suction
- resuscitation equipment
- emergency meds
- back up power source
5 Standard monitors for GA
- ECG
- BP
- Pulse ox
- Ventilation (ETCO2)
- Body temp
Endotracheal intubation is contraindicated in laryngeal disruption or laryngotracheal separation. What should you do instead?
Wake surgical tracheostomy
Le Fort fractures
Le Fort I: roof of mouth and palate separated from face
Le Fort II: nose and palate sep from face
Le Fort III: entire face affected
What should you pay attention to regarding Le Fort II and III fractures?
II and III are assoc. w/ cribriform plate disruption
- presence of hemotympanum
- CSF rhinorrhea
- Racoon eyes
- mastoid ecchymosis (battle signed
Pts on antithrombotic or thrombolytic therapy for > __ days need to have platelet counts checked before neuraxial block or catheter removal
4 days
- pts at risk of HIT