Mock exam 1 Flashcards
lipophilic opioids in continuous epidural infusion most likely provide analgesia by:
- acting systemically
- fentanyl, sufentanil
hydrophilic opioids in continuous epidural infusion most likely provide anesthesia by:
- acting in the spinal cord
- superior analgesia
- morphine, hydromorphone
Most appropriate interventions for “can’t intubate, can’t ventilate” situation
- surgical cric
- transtracheal jet ventilation
Methadone
- only narcotic known to prolong QTi
- torsades de points
- antagonizes NMDA, inhibits 5HT & NE, agonizes opioid receptors
LA made of 3 components:
- Aromatic ring
- Intermediate chain
- Tertiary amine
Aromatic ring
confers lipid solubility
Intermediate chain
determines metabolism & allergic potential
Tertiary amine
confers H2O solubility
Allergic reaction more common in ester or amide LA?
ester (1 “i”)
Allodynia
nonpainful stimulus evoking painful response
Hyperalgesia
exaggerated pain response
Neuralgia
pain localized to a dermatome
Dyesthesia
abnormal painful sensation
Recommended bladder width of BP cuff
40% of the circumference of the extremity
BP cuff that is too small will give a fale
high reading
BP cuff that is too large will give a false
low reading
Conditions that increase risk of endocarditis & warrant ABX prophylaxis
- previous infective endocarditis
- prosthetic heart valve
- heart transplant w/ valvuloplaty
- unrepaired cyanotic congenital heart defect
- dental procedures
- resp procedures that perforate mucosal lining
West Zone 1
- dead space
- P alveolar > P arterial > P venous > P intersitial
West Zone 2
- matched V/Q
- P arterial > P alveolar > P venous > P interstitial
West Zone 3
- shunt
- P arterial > P venous > P alveolar > P interstitial
West Zone 4
- increased pressure in interstitium (pulmonary edema)
- P arterial > P intersitial > P venous > P alveolar
Bullae
- large air-filled spaces
- rupture can lead to pneumo, tension pneumo, CV collapse
- To prevent rupture: SV until chest opened
- small Vt w/ high RR to minimize intra-alveolar pressure
- AVOID N2O
- DLT airway of choice
Amine
NR3
Alcohol
ROH
Ether
ROR’
Ester
RCOOR
Risk factors ischemic optic neuropathy post spine surgery
- Wilson frame
- Greater EBL
- Low ratio of colloid:crystalloid resuscitation
- male
- obese
- long surgery
Direct current cardioversion
Indications:
- aflutter, afib
- 1st shock = 50-100 j
- increase incrementally to max 360 j
Cutting tip needle
- Quincke
- Pitkin
increased risk of PDPH
Pencil point needle
- Sprotte
- Pencan
- Whitacre
decreased risk of PDPH
Round bevel tip needle
Green
Spinal cord protective strategies during thoracic aorta coss slamp
- hypothermia (30-32 C)
- CSF drainage
- Proximal HTN
- avoid hyperglycemia
- partial CPB
- steroids, CCBs, mannitol
Gas embolism
- “air lock” in right heart
- S/S
- Dec EtCO2
- Inc PAP
- Pulm edema
- low BP
- hypoxia
- dysrhythmias
- cyanosis
- mill wheel murmur
- TEE most sensitive indicator
Greatest risk of gas embolism during laparoscopic surgery
initial insufflation
Na+ nitroprusside & SpO2
- dilates pulm vasculature
- counteracts HPV
- increases intrapulm shunt (zone III)
- decreases SpO2
Pyloric stenosis electrolyte & acid/base imbalance
- olive-shaped mass
- projectile vomiting
- low K+, H+, Cl-
- hypokalemia, hypochloremic, metabolic alkalosis
Losartan
- angiotensin II antagonist
- SE: hyperkalemia
- increases lithium reabsorption
- avoid in pregnancy
- vasoplegia
Treatment of vasoplegia resistant to volume, neo, epi, NE
vasopressin
lung volume that increases w/ age
residual volume
Abdominal compartment syndrome
- IAP > 20
- decreases CO, venous return
- increases SVR
- decreases diaphragmatic excursion
MAP formula
MAP = (SBP x 1/3) + (DBP x 2/3)
complication of rapid correction of chronic hyponatremia
central pontine myelinolysis
Drugs to avoid w/ carcinoid crisis
- sux
- atracurium
- thiopental
- epi
- NE
- isoproterenol
Consequences of inadequate pain control in pt undergoing abdominal surgery
- decreased Vt, VC, TLC, FRC
- inability to clear secretions
- hypoxia
- atelectasis
- SNS stimulation
- PLT aggregation & venous stasis
- increased urinary sphincter tone - urinary retention
Recommended timing of epidural placement
- individualized
- after approved by OB, ok to proceed
Drugs that interfere w/ SSEPs
- decrease amplitude & increase latency
- VA, N2O, propofol, barbs, benzos
Drugs that do NOT impair w/ SSEPs
- ketamine
- precedex
- etomidate
- opioids
- droperidol
Unilateral RLN injury
hoarseness
Bilateral RLN injury
- stridor
- dyspnea
- aphonia (chronic)
Aldrete score
Dorsal resp group
inspiration
Ventral resp group
expiration
Apneustic center
stimulates DRG
Pneumotaxic center
inhibits DRG
Elderly have ______ clearance & _____Vd
decreased, decreased
Bleomycin
- pulmonary fibrosis
- at risk for O2 toxicity
- Keep FiO2 < 30% to maintain SpO2 > 90%
Piston ventilator
- electric
- will not consume O2 tank in pipeline failure
- PP relief valve opens if circuit pressure > 75
- Negative pressure relief valve opens at - 8
LFT: assess synthetic function
- PT
- INR
- albumin
LFT: assess hepatocellular injury
- AST
- ALT
- GST
LFT: assess cholelithiasis
- alk phos
- GGTP
Opioid receptor
- GPCR
- inhibit adenylyl cyclase
- block conversion of ATP to cAMP
- pre-syn nerve - reduced Ca+ conductance decreases NT release
- post-syn nerve - increased K+ causes hyprepolarization
Glucagon
- antagonizes insulin
- stimulates gluconeogenesis in liver
- produced by alpha cells in pancreas
- causes N/V
- increases myocardial contractility by increases cAMP
- useful for BB OD, CHF, low CO
Distance from subclavian CVC to CAJ
10 cm
Distance from RIJ CVC to CAJ
15 cm
Distance from LIJ CVC to CAJ
20 cm
Distance from femoral vein CVC to CAJ
40 cm
Distance from right median basilic vein CVC to CAJ
40 cm
Distance from left median basilic vein CVC to CAJ
50 cm
CBF decreases _____ ml/100g/min for every ___ mmHg PaCO2 (directly proportional)
1-2, 1
PE
- decrease EtCO2
- tachycardia
- increased CV filling pressures
- hypotension
Tx: 100% FiO2, HD support w/ fluids, inotropes
Transplanted heart
- severed from autonomic influence
- HR is determined by intrinsic rate of phase 4 depolarization of SA node (100-120 bpm)
- HR fixed
- CO dependent on preload
- use direct-acting drugs (isoproterenol, epi)
- indirect (ephedrine) less effective
- 2 p waves on ekg
Oculocardiac reflex
- five & dime / V (trigeminal) & X (vagus)
-Tx: remove stimuli, 100% O2, anticholinergic
Most common causes of perioperative allergic reactions
NMBs > Latex > ABX > Protamine
Best drug for extraction of retained placenta
- NTG
- relaxes uterus
- facilitates manual removal
- venous > arterial
cocaine dose
1.5 - 3.0 mg/kg not to exceed 200 mg
Bite on tongue blade > 5 sec
50% receptor blockade (most sensitive)
DB stimulation w/o fade
60% receptor blockade
TOF 4/4
70% receptor blockade
Vt 5 ml/kg
80% receptor blockade
Brugada syndrome
- ion channelopathy
- common in males from Southeast Asia
- RBBB w/ ST elevation in precordial leads V1-V3
WPW
- paroxysmal SVT
- short PRi, delta wave, wide QRS
Lenegre’s dz
- His-Purkinje defect
- long pauses, wide QRS, brady
Mannitol
- inhibits H2O reabsorption in PCT & LOH
- dose = 0.25-1 gram/kg
Hydralazine
- increases cGMP
- arterial > venous dilation
- bareceptor reflex preserved
- tachycardia common
- dose = 2.5-20 mg IV
- can cause lupus
Postop delirium
acute confusion occurs 1-5 days postop
Final products of soda lime reaction
- sodium hydroxide (NaOH)
- calcium carbonate (CaCO3)
Nightshade (Belladonna)
- Anticholinergic OD
- S/S result of muscarinic antagonism
- flushing, mydriasis, dry mouth, confusion, hallucinations, hyperthermia, tachycardia
- ” red as a beet, blind as a bat, dry as a bone, mas as a hatter, hot as a hare”
-Tx: physostigmine - increases Ach available at muscarinic receptors
Most common causes of hypocalcemia in the OR
- hyperventilation (reduces ionized ca+)
- administration of citrated blood products greater than 1.5 ml/kg/min
1 U PRBC increases Hgb by
1 g/dL
1 U PRBC increases Hct by
2-3%
Nerve fibers that transmit tourniquet pain
- C fibers
- slow pain
- tourniquet pain begins 45-60 min after inflation
RCA monitored by which leads & supplies which part of heart?
- II, III, aVF
- RA, RV, SA/AV node, inferior LV
LAD monitored by which leads & supplies what part of heart?
- V3-V5
- anterolateral LV
Circumflex monitored by which leads & supplies what part of heart?
- I, aVL
- Lateral LV
Near-infrared spectroscopy
- assesses cerebral venous O2 sat
- monitors regional cerebral ischemia
C1 esterase inhibitor deficiency
- hereditary angioedema
- increased bradykinin
- Tx: FFP (contains C1 esterase)
B:G sevo
0.65
B:G iso
1.4
B:G des
0.42
B:G N2O
0.47
Effects of tourniquet release
- CO2 builds up in ischemic limb
- delivers large amounts of CO2 to pulmonary circulation
- transiently increases EtCO2
- dysrhythmias, hypotension, bradycardia, decreased temp
Pheo
- catecholamine secreting tumor (NE > epi)
- S/S = HA, diaphoresis, tachycardia
- Block alpha BEFORE beta (A comes before B)
- Tx: BB, alpha blockers, Nitroprusside
Joule Thompson effect
gas stored at high vapor pressure that is suddenly release escapes form its container into vacuum. Temp falls. Explains why O2 cylinder opened quickly feels cool to touch
dermatome bladder procedures
T11-L2
dermatome prostate & bladder neck procedures
S2 - S3
dermatome for TURP
T10
Retrograde intubation
- puncture cricothyroid membrane & pass wire through VC out mouth
- ETT loaded over wire & advanced into trachea
- mostly used in c-spine injuries
- contraindications: goiter, neck flexion deformity, coagulopathy
Ulnar nerve injury
- more common in males, obese, cardiac surgery, pre-existing nerve patho
- pronation on armboard increases risk
- ideal on armboard = supination
- ideal tucked = neutral
Gastroschisis
- right of umbilicus
- not covered by sack
- prematurity
Omphalacele
- midline
- covered by sac
- associated w/ congenital defects: beckwith, heart dz, trisomies 13/18/21, cantrell
superior rectus eye movement
supraduction (CN 3)
inferior rectus eye movement
infraduction (CN 3)
medial rectus eye movement
adduction (CN 3)
lateral rectus eye movement
abduction (CN 6)
superior oblique eye movement
intorsion/depression (CN 4)
inferior oblique eye movement
extorsion/elevation (CN 3)
BMI formula
kg/m^2
inch to cm = in x 2.54
cm to meter = cm / 100
adenosine should not be given to which pt d/t increased risk of bronchospasm?
asthma
Non-OB surgery
- delay until 2nd trimester
- fetal risks: growth restriction, LBW, demis, preterm labor
- avoid N2O, benzos
- regional if appropriate
- fetal monitoring
________________ is the most reliable method to reduce postop pulmonary complications
smoking cessation
therapeutic index
TI = LD50/ED50
