Startprep 2 Flashcards
Which costal cartilage is the level of the Xiphosternum?
7
Complications of CVC in neck
- carotid puncture
- pneumothorax
- hemothorax
- chylothorax
- venous thrombosis
- infection
- brachial plexus injury
- arrhythmias
external jugular vein
- sometimes used for CVC
- More for PIV
- CVC: acute angle to subclavian vein–>challenging
- surface of sternocleidomatorid muscle obliquely
blindly RIJ CVC from Sadiq
sternal notch–>hold medial head of SCM–>3 fingers above clavicle–>test needle–>point to nipple–> blood–>
MAC vs moderate sedation
Moderate sedation can be performed by non-anesthesiologists, but it is not called Monitored Anesthesia Care
What levels of sedation are part of the definition of MAC?
All levels
What factors distinguish MAC from sedation/ analgesia?
- MAC is conducted by an anesthesia provider & may include all levels of sedation
- Sedation can be performed by providers trained in sedation & should not include deep sedation or GA
Body H2O
- 60% of TBW
- 5% TB H2O intravascular
- 35% interstitial
- 60% intracellular
BNP
- brain natriuretic peptide
- first isolated from porcine cerebrum
- Not released by human brain
- released by ventricular myocytes in response to ventricular tension
- ANP= atrial natriuretic peptide
- ANP & BNP: antithesis of aldosterone
Mechanism of action of aldosterone
- upregulate Na/K pumps in distal convoluted tubule
2. insert Na channel into collecting duct
PG E2
renal ischemia protection by vasodilation
etomidate
- beta subunit of GABAa-R–>enhance affinity of GABA
- anesthetic, amnestic, NOT analgesic
- hemodynamic stable
4 onset of 30 to 60 S, peak 1 min, redistribution–>3-5 min - 0.2-0.4 mg/kg
- propylene glycol–>stinging
- 75% protein bound
- mainly eliminated via Kidney
indications of etomidate
- Induction of GA: sicker pt w/ hymodynamic compromise, like trauma or critical care
- brief hypnosis: retrobulbar block, ER procedure, cardioversion, ECT (prolong seizure)
- help localizing seizure foci vs terminating seizure in status epileptics
- No histamine release
effects of etomidate
- mild on respiration
- decrease ICP and IOP
- adrenocortical suppression: 5-8 hrs after single dose (inhibition of 11-beta-hydroxylase)
- myoclonus
- N/V
Barbiturates
- highly alkaline–>bacteriostatic
- anticonvulsant
- Methohexital: stimulate seizure
- GABAa receptor–>prolong
5 induction dose: thiopental or thiamylal: 3-5mg/kg learn BW - barbiturate coma
Barbiturates: indications
- induction of GA: thiopental 3-5 mg/kg, methohexital 1-1.5 mg/kg
- ICP: infusion or bolus
- Short procedures: Cardioversion or ECT
- Phenobarbital: increase glucuronyl transferase–> treat hyperbilirubinemia & kernicterus
Muscle relaxant vs antibiotics
- prejunctional: (-) release of Ach
- Postjunctional: (-) sensitivity of nAChR to Ach
- aminoglycoside, polymyxins, lincomycin & clindamycin: pre- & post-
- Tetracycline: post-
- cephalosporins & penicillins: safe
Muscle relaxant vs antiepileptic drugs
- anticonvulsants: (-) release of Ach
- chronic anticonvulsant–>resisentce to NDNMBs
- (+) sensitivity to succinylcholine
Muscle relaxant vs lithium
- prolongation of both NDNMBs & sux
2. decrease to dose to titrate
Muscle relaxant vs Mg
- pre & post junctional:
- decrease initial dose, titrate following dose
- limited to no clinical effect on succinylcholine.
Muscle relaxant vs volatile inhaled anesthetics
- (+) NDNMBs, but not N2O
2. desflurane > sevoflurane > isoflurane > halothane > nitrous oxide–barbiturate–opioid or propofol anesthesia
Drug reactions
- anaphlactoid
- anaphylaxis
- idiosyncratic
anaphylaxis
- type I hypersensitivity
- begin: w/i 5min—>2 hrs
- tryptase (from mast cells): sensitivity >90%, specificity just over 50%
mgmt. of anaphylaxis
- epi: 50-100mcg IV or 0.3-0.5mg IM; if no hypoTN–>10-20 mcg initial
- Short-term goals:
Remove antigen–>FiO2=1–>airway(ET, tracheostomy or cricothyroidotomy)–>fluid for hypoTN–>titrate Epi–>vaso, noepi or neo–> (H-1 blocker: Benadryl + H2 blocker: ranitidine 50mg; hydrocortisone 1gm or methylprednisolone 125 mg; albuterol; NaHCO3; glucagon 1-5 mg if unresponsive to epi
ANAPHYLACTOID REACTION
- NOT mediated by IgE
- all other type of AB or direct drug-induced histamine release
- IV radiocontrast medium MCC
Pretreatment of anaphylacoid reaction
- Benadryl: 50 mg IV, IM, or PO 1 hr prior
- ephedrine
- corticosteroids: >12 hrs prior to contrast: prednisone 50 mg po 13, 7, 1 hr prior
MCC of A-a gradient
Shunting
N2O vs ventilator response to increased CO2
No effect
Promethazine
Promethazine is a phenothiazine and has been shown to be efficacious for treatment of nausea and vomiting at a dose of 6.25mg IV.
two most common types of advance directives
living wills and durable power of attorney for health care.
corpus striatum of the basal ganglia
- putamen
- caudate nucleus
- nucleus accumbens
brainstem
- midbrain
- pons
- medulla oblongata
Ataxic respiration
result from lesions in the dorsomedial medulla and may be accompanied by hypersensitivity to respiratory depressants. It is considered preterminal
Apneustic breathing
long, gasping inspiration with poor expiration, indicating a pontine injury
Cluster breathing
irregular in frequency and amplitude with variable duration of apneic periods
Cheyne-Stokes respirations
- hyperpnea alternating with apnea in a smooth crescendo-decrescendo pattern.
- bilateral injury to cortex and forebrain structures
What are the risk factors in the Apfel risk score system?
- female
- nonsmoker
- PONV or motion sickness hx
- use of post-op opioids
What is the determinant of mivacurium’s relatively short duration of action?
it is rapidly hydrolyzed by pseudocholinesterase.
What are the characteristics of phase I block?
- decreased twitch amplitude
- sustained response to continuous (tetanic) stimulation
- similar decreases of all twitches in the train-of-four (ratio>0.7)
- absence of post-tetanic potentiation
- antagonism by nondepolarizing muscle relaxants
- augmentation by anticholinesterase drugs
VAE
- Decreased ETCO2
- Increased PaCO2
- Increased ETN2
Cyanide
- Sodium thiosulfate combines with unbound cyanide to form thiocyanate
2.
MC perioperative PNI
ulnar nerve injury
neuropathies
- Neurapraxia
- Axonotmesis
- Neurotmesis
Treatment protocol for VAE
- Notify surgeon to flood field field with NS
- Turn off nitrous
- Bil Jugular V compression
- Aspiration of air from CVC
- CV support
- head-down, lateral decubitus position
How GA interferes with the eye’s natural reflexes to protect the cornea
- Mask pain perception
- Decreases tear production
- Abolishes of Bell’s phenomenon
- Promotes lagophthalmos
Five signs and symptoms of PA ruptures
- hemoptysis
- hemothorax
- dyspnea
- anxiety
- hypotension
inodilator
- milrinone
- other phosphodiesterase III inhibitors
- dobutamine (contraversal)
which holds a greater quantity of sevoflurane, a milliliter of blood or a milliliter of gas?
a milliliter of blood
Identify the physical findings in each of the four classes of the Mallampati Classification
I: tonsillar pillars
II: Uvula fully visible, fauces visible
III: base of uvula visible only
IV: hard palate
Which factors may predict difficulty mask ventilation?
- Obesity: BMI>30
- Mallapampi: III-IV
- Beard
- Edentelous
- Limited Jaw extension
- Snoring
- OSA
- age>55 yo
When should noninvasive cardiac testing be considered?
When it could change mgmt.: pts w/ poor exercise capacity & 3 clinical risk factors undergoing intermediate risk surgery or 1-2 clinical risk factors for high or intermediate risk surgery
At what dose of succinylcholine dose the risk of phase II block occur?
The risk of phase II block occurs when the dose of succinylcholine exceeds 6 mg/kg IV, typically administered over an extended period of >30 mins
What is the time of onset for symptoms of Transient Neurologic Synptoms ( TNS)?
12 to 24 hrs
What is fractional saturation?
SaO2 = O2Hb/(O2Hb + RHb + MetHb) x 100%
Up to what percentage of AchRs may remain occupied by a NMBD for each of the following responses?
75%<—DBS (no fade)
What are the four phases of diastole?
Isovolumic relaxation
early filling
diastasis
atrial contraction
how does etomidate affect the EEG?
Low concentration–>activated
High—>inhibited
What is the location of superior mediastinum?
posterior to the manubrium sterni and anterior to bodies of first four thoracic vertebrae
What is located in the diaphragm at T8, T10, T12?
T8: IVC
T10: esophageal hatus
T12: aortic hatus
Histamine release is a consequence of which three opioids?
Morphine
Meperidine
Codeine
What is the MC agent responsible for anaphylactoid reactions?
IV contrast agent
What causes a leftward shift of the CO2 response curve? (Decrease ventilation for level of PCO2)
metabolic alkalosis, CNS depressants, denervation of the carotid body, sleep
How do loop diuretics affect warfarin and clofibrate?
increase the unbound drug, increasing the free drug available
RA should be waited how long after these meds?
abciximab (ReoPro): 48hrs
Ebtifibatide (Integrilin): 8 hrs
Tirofiban (Aggrastat): 8hrs
primary effects of ACE inhibitors
◾decrease in Ang II formation,
◾increase in bradykinin,
◾increase in prostacyclin,
◾decrease in aldosterone and ADH production
DDAVP (desmopressin)
- only clinically available V2 agonist
2. release von Willebrand factor and factor VIII
At present the only clinically used vasopressin analogs
- argipressin (AVP)
- terlipressin (TP)
- desmopressin (DDAVP)
argipressin (AVP)
- binds to all vasopressin receptor subtypes
- 0.04 u/min to 0.1 u/min
- useful in preventing and treating intraoperative hypotension in patients on ACEI and ARBs
Methylene Blue
- inhibit NO system
- single 2 mg/kg IV over 20 min
- infusion 0.5 mg/kg
ARBs (valsartan) or ACEI
- hypotension can be resistant to phenylephrine, epi or norepi
- Vasopressin infusion or low dose bolus of 0.5 - 1 unit can restore the sympathetic response
- withheld 24 hrs before elective surgery
should all patients have a preoperative uninalysis?
No, only pts who have urinary symptoms or who are having a prosthesis implanted
which holds a greater quantity of sevoflurance, a ml of blood or a ml of gas?
blood
What is the definition of a surgical emergency?
Am emergency exists when life, limb, sight or baby is at immediate risk w/o surgical intervention
How do you explain the rapid recovery after a prolonged administration of propofol?
Propofol slowly diffuses from poorly perfused peripheral compartment into the central compartment where it is rapidly and extensively metabolized.