True Learn. Basic. Flashcards
What is the Haldane effect?
Deoxygenated hemoglobin has higher affinity for CO2
Spread of local anesthetic within the CSF is primarily affected by what?
Baricity of anesthetic and patient position
St. John’s Wart induces what enzyme?
P450 3A4
What is the recommended technique to verify venous placement of central line?
Performing column mamometry
What is the first sign of intravenous Lidocaine toxicity/
Numbness of the lips
What has the largest effect on epidural spread of local anesthetic?
Total mass of local anesthetic
What are 5 side effects of sodium bicarb administration?
Increases: -PaCO2 -EtCO2 -Intracranial Pressure Decreases: -Serum Calcium -Serum Potassium
Name 8 conditions that cause up-regulation of nicotinic acetylcholine receptors
- Stroke
- Burns
- Prolonged immobility
- Duchenne muscular dystrophy (myopathies)
- MS
- Guillan Barre
- ALS
- Spinal Cord injuries
Why is Myasthenia Gravis not a contraindication to Succs?
Because it is caused by an antibody to the NAChR which actually decreased the number of receptors. (upregulation is contraindication)
What is the major landmark for performing a stellate ganglion block?
Chassaignac tubercle which is transverse process of C6
What is the appropriate treatment for methemoglobinemia in patient with G6PD deficiency?
Ascorbic Acid
What is assist-control ventilation?
If the patient is not breathing it is essentially VCV. Tidal volumes and minimal RR are set. If patient is breathing the ventilator synchronizes to deliver tidal volume in a positive pressure breath. Spontaneous breathing of the ventilator is not allowed.
What is approximate vital capacity for 70 kg adult?
About 5L
What is ED95 (NMBD)?
The dose of a paralytic at which 95% twitch suppression is achieved in 50% of population
What affects how Nitric oxide will function in the body?
Site of production
At what Magnesium level do you begin to see ECG changes?
6-12 mg/dL
What are two ways to increase output of vaporizer?
Increasing fresh gas flow and decreasing barometric pressure*
What is the unique side effect of IV anesthetic Methohexital?
Seizures
There are three types of MAC. List them in order
MAC awake
What are the risk factors of POCD (postoperative cognitive disfunction)?
Advanced age, lower education level, history of previous cerebral vascular accident without residual impairment.
What class of drugs cause extrapyramidal symptoms and what class treats them?
Antidopaminergic. Anticholinergic.
Which test is most useful to diagnose acute abnormalities in hepatic synthesis?
Prothrombine time
What are the functions of the first and second stage oxygen regulators?
First: shut off lower pressure O2 tank when high pressure pipeline is sensed. Second: decrease pressure to slightly above atmospheric pressure
What factor most influences initial recovery from an induction dose of thiopental?
Redistribution to peripheral tissues.
What is most likely observed on ECG after multiple blood transfusions in liver dysfunction patient?
Prolonged QT interval 2/2 hypocalcemia.
What are the 5 elements of the Aldrete PACU discharge criteria?
Extremity activity. Breathing. O2 sat. BP. Consciousness
Of the common gasses which has the highest blood:gas coefficient? Lowest?
Isoflurane. Desflurane
Name 5 drugs associated with pain on injection
Propofol, Rocuronium, Diazepam, Etomidate, Methohexital
Which nerve is responsible for bronchoconstrictiom?
Vagus
In LAST how is epinephrine dosed?
Less than normal (1 mg). Dose at <1 mcg/kg
What is the arterial oxygen content equation?
CaO2=(Hbg1.36SaO2)+(0.003*Pa02)
What is treatment for hyperkalemia?
C BIG K DROP
Calcium gluconate. 10 ml Beta agonist Bicarbonate Insulin 10 units Glucose D50 one ampule
Kayexalate 15-30 g
Diuretics
Renal unit for dialysis of Patient
what is the effect of nicardipine?
Reduces BP by reducing afterload with minimal effect on preload.
What is nesiritide?
Recombinant form of BNP. Causes vasodilation, diuresis, natriuresis
What is the equation for SVR?
SVR= [80 * (MAP-RAP)] / CO
Describe the branches and function of Superior Laryngeal Nerve
Internal and external branches. Internal branch provides sensation to larynx above vocal cords. The external branch is motor and innervates the cricothyroid muscle.
What are guidelines for surgery in patient with CAD requiring stenting? When to perform surgery and what anti platelet meds to continue perioperatively?
Consider: Urgency of surgery, risk of bleeding, severity CAD.
Which nerve fibers transmit nociceptive info? Which is faster?
A-delta and C fibers. A-delta a myelinated and faster. C for dull pain
Order of local anesthetic systemic absorption. (Vascularity)
IV-tracheal-intercostal-caudal-epidural-brachial plexus-LE blocks
Why is Ketamine contraindicated as sole induction agent in severe CAD?
It acts as a sympathomimetic and increases heart rate and BP
How is esmolol metabolized?
Red Blood Cell Esterase
Esmolol = esterase
Acronym for Beta 1 selective blockers (cardioselective)
BEAM
What is the equation for mixed venous oxygen? What is normal value?
SvO2=SaO2-{VO2/(COHbg1.35)}
75%
Where is Nicardipine Metabolized?
Liver
What is the difference between first order and zero order kinetics?
In zero order there is a constant amount of drug metabolized. In first order it is a constant percentage that is metabolized. Liver blood flow affect first order no zero order.
Metoclopramide (Reglan) is contraindicated in what? Why?
SBO. Because it is a promotility antiemetic
What are 5 risk factors for CAD?
- History Ischemic heart disease
- CHF
- CKD
- History Stroke
- DM
Which cardiovascular med can NOT be administered IM?
Norepinephrine
What are risk factors for emergence reactions with Ketamine?
- Age
- Female
- Dosage
- Psychologic Susceptibility
- Concurrent Meds (Benzos preop decrease risk)
What is the order of non-depolarizing muscle relaxant potentiation?
Desflurane>evoflurane>Isoflurane>Halothane>TIVA
Why does nitrous have a faster onset than Des even though it is more soluble (higher blood:gas coefficient)?
Concentration effect
What cardiac side effect can be caused by Methadone?
QT prologation
Describe the four possible Lehane-Cormack Laryngeal Views
Grade: I: Entire laryngeal aperature II: Posterior third of glotis IIa: Arytenoids and posterior cords IIb: Arytenoids and epiglottic edge III: Only epiglottis visible IV: No view of any airway structures
Treatment for stridor and difficult ventilation in fixed airway obstruction (such as subglottic stenosis)?
Helium/oxygen 70/30. This is because Helium is more dense and will decrease resistance in turbulent flow.
What is the effect of metabolic alkalosis on respiratory drive?
There is a 0.5 mmHg increase in PaCO2 for every 1 mEq/L increase in Bicarb. Alkalosis can cause hypoventilation (retain Co2 to decrease pH)
What is the pneumonic for K sparing diuretics?
K+ STAys with Spironolactone, Traimterene, Amiloride
What is the closing capacity? What reduces it?
The volume at which small airways begin to close. it is decreased by (ACLS-S) Age, chronic bronchitis, LV failure, smoking, surgery
What is Rocuroniums mechanism of action?
Competitive antagonist at postsynaptic nicotinic acetylcholine receptors.
What is the Frank-Starling effect of phenylephrine?
Increased both preload and afterload (venous and arterial constriction), increased LVEDV and increased stroke volume
Is succs safe to use in asthma?
Yes. Even though it does cause Histamine release, it is not associated with bronchoconstriction.
What is the mechanism of action of Ketamine?
NMDA receptor antagonist. NMDA are excitatory glutamate receptors.
List inhaled anesthetics in order of metabolism, from greatest to least (3)
Sevo>Iso>Des
What class of drug is glycopyrrolate?
Anticholinergic
What class of drug is neostigmine?
Cholinesterase inhibitor
When reversing, what cholinesterase inhibitor is paired with atropine?
Edrophonium
ASA should be held for what cases?
intracranial neurosurgery, mild ear, posterior eye, intramedullary spine, +/- prostate
What is a major side effect of Dantrolene?
Liver failure
What is the equation for standard error of the mean?
SEM= standard deviation/square root of n (where n=population)
what factors INCREASE MAC?
Drug Amphetamine, Cocaine, Ephedrine, Chronic EToH Age highest at 6 months Electrolyte Hypernatremia Hyperthermia Red Haird
What factors shift the oxygen dissociation curve right. Mnemonic?
When is 2,3 DPG the highest?
RIGHT.
Rise In 2,3 DPG, H+, temperature.
Highest at 12 months of age. This results in lowest affinity and highest P50
What are NPO guidelines?
2 Hr: Clear liquids
4 Hr: Human Breastmilk
6 Hr: Light meal, non-human breast milk
8 Hr: Fatty foods
What happens to serum osmolarity after large LR infusion? Why?
Serum osmolarity with decrease because LR is actually slightly hypoosmolar. 273-275 mOsm/L where serum is 275-295 mOsm/L
What is the relationship of partial pressure of inhaled anesthetics between CNS, blood and alveoli?
PCNS=Pblood=Palveoli
What is the mechanism of action of dantrolene?
Directly blocks calcium release from sarcoplasmic reticulum intracellularly.
At what spinal cord level does to artery of adamkiewicz generally originate?
T9-T12
What adrenergic receptors are associated with cardiac sympathetic stimulation?
Alpha 1, beta 1, Beta 2
What factor is most likely responsible for release of vasopressin?
increased plasma osmolality
Carotid body chemoreceptors are stimulated by what?
decrease in PaO2 less than 60-65 mmHg
Describe series of events after Mannitol administration
Initially increase in plasma volume and cardiac output. This is followed by diuresis leading to reduced intravascular volume and potentially reduced BP and CO
What medication is best for n/v associated with high spinal blockade?
Atropine
What is the formula for static respiratory compliance?
Cs=Vt/(Ppl-PEEP)
What percentage of platelets are restored one day after discontinuing antiplatelet medication?
10-14% (per day)
What is the metabolite of hydromorphone? Is it active or inactive? What is its effect in renal failure (accumulation)?
hydromorphone-3-glucuronide (H3G).
Inactive.
Neuroexcitatory/neurotoxic
What causes a plateaued inspiratory flow on flow-volume loop?
Variable extra thoracic lesion (unilateral vocal cord paralysis)
What is the result of excessive dose of neostigmine and what is the recommended max dose?
Prolonged weakness.
0.07mg/kg
What are two complications occur more frequently in left-sided central line placement?
Chylothorax (unique to left side)
Carotid artery puncture (more common)
Patient has been receiving Heparin for more than 5 days. What needs to be checked before placing epidural? Why?
Platelets. To check for HIT
How does ischemic optic neuropathy present?
Sudden painless vision loss
Is propofol a vesicant?
Nope
Where does Vasopressin work?
V1 receptors
What is the most common risk of autologous blood transfusion?
Infection (from improperly stored blood)
Transfusion-associated sepsis (TAS) is most associated with transfusion of what product?
Platelets
Patients with IgA deficiency receiving blood are at increased risk of what?
Anaphylactic response to IgA in donor blood
What is reason for low grade fevers following blood transfusion?
Host antibodies to HLA antigens on donor leukocytes
What are Amiodarone’s side effects?
bradycardia, hypotension, hypothyroidism, thyroid storm, QT prolongation, pulmonary fibrosis, elevated liver enzyme markers.
What is the alveolar gas equation?
PAO2=FiO2(PB-PH20)-PCO2/RQ
PB=760
PH20=47
RQ=0.8
What is the mechanism of action of Metformin?
Decreased hepatic gluconeogenesis and increases insulin sensitivity
Under what two circumstances does the odds ratio estimate the risk ratio?
Cohort study, low incidence
What is the NYHA classification of heart failure?
Based on symptoms
Class I: No limitation in normal activity
Class II: minor limitation, slight symptoms with normal activity
Class III: Significant activity limitations, only comfortable at rest
Class IV: Symptoms at rest
Primary hyperparathyroidism has what affect on acid/base status?
Normal anion gap metabolic acidosis as it can increase renal bicarb loss
What is first line treatment for stable Afib with RVR?
Beta blocker
What is mechanism of action of barbituates (and propofol)?
Decrease dissociation of GABA from its receptor
What are Propofol’s affects on the respiratory system? (3)
- Dose-dependent apnea
- Bronchodilation in COPD
- Potentiation of hypoxic pulmonary vasoconstriction
Treatment for stable SVT?
Adenosine
Name three congenital heart defects dependent on PDA.
- Transposition great vessels
- Pulmonary atresia
- Hypoplastic heart
