TL Pages 1-5 Flashcards
What is the most common side effect of inhaled albuterol?
Tachycardia. It can also cause PVCs, hypokalemia (via intracellular K⁺ shifts), and hypotension.
What does a low blood:gas coefficient indicate about an inhaled anesthetic?
It has a fast onset and offset (low solubility).
What blood products can be safely administered through a fluid warmer?
fBRc, FFP, platelets, and cryoprecipitate.
What temperature defines hypothermia?
<35°C.
Describe the afferent and efferent limbs of the laryngospasm reflex.
Afferent: internal branch of superior laryngeal nerve. Efferent: recurrent laryngeal and external branch of superior laryngeal nerve.
What is the anatomical relationship of the popliteal artery and vein to the semitendinosus tendon?
Artery is lateral to the tendon; vein is superficial and lateral to the artery.
How does norepinephrine affect the cardiovascular system?
α1 > α2 > β1 → vasoconstriction → ↑ BP & CO → reflex bradycardia modulated by ↑ SV & contractility.
How is plasma osmolality calculated?
Posm = (2 × Na⁺) + (glucose / 18) + (BUN / 2.8); normal ≈ 290 mOsm/kg.
Which drug has been shown to reduce perioperative AKI in CPB patients?
Dobutamine (not dopamine or fenoldopam).
What labs are used in the MELD score?
Creatinine, bilirubin, INR, sodium, dialysis frequency. Mnemonic: I Crush Seven Beers Daily.
What immune mechanism causes contact dermatitis?
T-cell mediated (delayed-type hypersensitivity).
What is the function of nitric oxide in the vasculature?
Vasodilation and inhibition of platelet aggregation (short half-life, seconds).
What is a Type I and Type II statistical error?
Type I: false positive (rejecting a true null). Type II: false negative (accepting a false null).
What is the most accurate method to confirm venous placement before CVL dilation?
Pressure waveform monitoring.
How does succinylcholine affect intraocular pressure (IOP)?
↑ IOP by 6–8 torr within 1–4 mins; returns to baseline in 5–7 mins. Blinking ↑ IOP by 10–15 torr.
How do local anesthetics work?
Bind voltage-gated Na⁺ channels → block Na⁺ influx → inhibit action potential propagation.
What are the effects of dexmedetomidine on the brain and respiration?
α2 agonist at locus coeruleus/spinal cord → sedation, analgesia, ↓ CBF & CMRO₂. Preserves respiratory drive, but ↓ TV & minute ventilation.
What anesthetic and drug increase the risk of postoperative shivering?
High-dose remifentanil and sevoflurane.
What is the initial dose of lipid emulsion for LAST?
1.5 mL/kg bolus of 20% lipid emulsion, then 0.25 mL/kg/min infusion.
How is cisatracurium eliminated?
Hofmann elimination; increased with higher pH and temperature.
Which reflexes are lost with neuromuscular blockers?
Corneal, oculocephalic, and gag reflexes; light reflex remains.
Why is midazolam dosed lower in uremia?
Decreased protein binding increases free drug fraction.
How does normal saline compare to human plasma osmolality?
NS is hyperosmolar; LR is hypoosmolar; Plasma-Lyte is iso-osmolar.
What is the Armitage formula for epidural volume dosing?
0.5 mL/kg for lumbosacral, 1 mL/kg for thoracolumbar, 1.25 mL/kg for mid-thoracic.
Name the nerve sheath layers from inner to outer.
Endoneurium (axons), perineurium (fascicles), epineurium (nerve).
What is clevidipine’s mechanism and metabolism?
Arteriolar vasodilation; rapidly metabolized by plasma and RBC esterases.
Why do infants need higher doses of water-soluble drugs?
They have higher total body water (~80%).
Most common side effect of amiodarone?
Bradycardia due to calcium channel blocking.
How does epinephrine affect renal blood flow?
Decreases RBF without affecting GFR.
How do benzodiazepines affect CO2 response?
Blunt ventilatory response to hypercapnia (decrease slope of CO2 response curve).
What are IV:oral alpha:beta block ratios of labetalol?
IV 1:7, oral 1:3.
Why use dexamethasone for peritumoral edema?
Decreases BBB permeability and tumor size.
What is the risk of meperidine in renal failure?
Seizures due to accumulation of normeperidine.
What is metoclopramide’s MOA for aspiration prophylaxis?
Dopamine antagonist; increases gastric emptying and LES tone.
What does a Class 3 upper lip bite test predict?
Difficult intubation; >60% chance.
How to manage vasopressor extravasation?
Elevate limb, warm compress, saline irrigation, phentolamine, stellate block.
How does obesity affect lung volumes?
↓ ERV, ↓ FRC, ↑ RR, ↓ TV; restrictive pattern.
What is the pressure:volume ratio of an O2 E-cylinder?
3:1 (2000 psi ≈ 625 L).
What does a Uosm:Posm ratio >1.5 indicate?
Prerenal oliguria (e.g. dehydration).
Why supplement intercostobrachial block in upper limb surgery?
Prevents tourniquet pain missed by brachial plexus block.
Normal intracardiac pressures?
RA 1-10, RV 15-30/0-8, LA 8-10, LV 90-140/4-12 mmHg.
Mnemonic for GCS components?
EVM: Eyes 4, Verbal 5, Motor 6.
What electrolyte state requires higher NMB doses?
Hypercalcemia.
Which muscles are last recruited during resp failure?
Paravertebral and large back muscles.
Where does artery of Adamkiewicz originate?
Left aorta, T9–L2; supplies lumbar/sacral spinal cord.
What AChR subunit defines immature junctions?
γ replaces ε; seen in burns, sepsis, denervation.
What percent of TBW is intravascular space?
8% of TBW; 1/4 of ECF.
What opioid risk is increased with MAOIs?
Meperidine → serotonin syndrome.
Define pharmacodynamics vs. pharmacokinetics.
Pharmacodynamics = drug effect on body; kinetics = body’s effect on drug.
What treats opioid-induced pruritus?
Nalbuphine or naltrexone.
What converts codeine to morphine?
CYP2D6 via O-demethylation.
How is succinylcholine metabolized?
By plasma pseudocholinesterase after diffusion from NMJ.
How does lithium affect NMBs?
Potentiates both depolarizing and nondepolarizing NMBs.
Which drugs lower MAC or prolong NMB?
Hypothermia, CCBs, antibiotics, magnesium, lithium, diuretics.
Context-sensitive half-time of ketamine?
Similar to propofol.
What does high blood:gas coefficient mean?
High solubility → slow onset.
Dexmedetomidine CV effects?
Bolus: HTN; infusion: bradycardia, hypotension.
Most common anesthesia-related errors?
Labeling, incorrect dosing, omission.
What is the Parkland burn formula?
4 mL × kg × %TBSA. Give ½ in first 8 hrs, ½ in next 16 hrs.
Which nerves injured by LMA use?
Lingual, hypoglossal, recurrent laryngeal.
Minimum PACU monitoring?
Every 15 minutes.
Steps in aspiration management?
100% O2, deepen anesthesia, Trendelenburg, suction.
Effect of lorazepam premedication?
Prolongs extubation, no improvement in satisfaction.
What is the half-life and metabolism of labetalol?
6 hours; metabolized via hepatic oxidation and glucuronidation.
Do neuromuscular blocking agents interfere with evoked potential monitoring?
No, they do not significantly impact evoked potentials.
What medication improves platelet dysfunction in uremic patients perioperatively?
Desmopressin (DDAVP).
What determines the spread of epidural anesthesia to a desired dermatome?
Volume of local anesthetic and capacitance of epidural space (inversely related to age).
How are most calcium channel blockers metabolized?
By hepatic cytochrome P450 enzymes.
What are key side effects and mechanisms of action of amiodarone?
AV block, QTc prolongation; blocks K⁺ channels → prolongs repolarization, blocks AV node conduction, no negative inotropic effect.
What makes amiodarone a good choice for patients with reduced EF?
It lacks negative inotropic effects.
What are the causes of peritumor cerebral edema?
Multifactorial: hydrocephalic (membrane leak), vasogenic (CSF obstruction), static (venous stasis from compression).
