Blast Basics Flashcards
1
Q
What is the anatomical landmark for each level:
C7
T4
T7
T8
T10
T12 -L4
L2
L4
L4-S3
S2
A
C7 vertebra prominens
T4 nipple line
T7 xiphoid process
T8 inferior border of scapula
T10 umbilicus
T2-L4 lumbar plexus
L2 termination of spinal cord adults
L4 iliac crest
L4-S3 sacral plexus
S2 termination of subarachnoid space in adults
2
Q
What is oculocardiac reflex (OCR)? Which nerves are involved?
A
10% decrease in heart rate associated with traction applied to extraocular muscles, direct pressure on the globe, ocular manipulation, and ocular pain.
Can lead to bradycardia , hypotension, junctional Rythm, ectopic beats, av block or asystole.
Reverted with atropine
Afferent Lomb mediated by trigeminal nerve. Efferent by vagus nerve.
3
Q
What drug is echotiophate? What is it’s interaction with succinylcholine?
A
Anticholinesterase used for glaucoma.
Increase the duration of succinylcholine.
4
Q
Which nerve innervates the larynx muscles? What’s the exception
A
All larynx muscles are innervated by the recurrent laryngeal nerve.
Exception to cricothyroid muscle, which is innervated by the external branch of superior laryngeal nerve.
5
Q
Innervation of upper airway:
A
Anterior 2/3 of the tongue: mandibular branch of the tirgeminal nerve (v5)
Posterior 1/3 of the tongue, Soft palate and oropharynx: glossopharyngeal (IX)
Hypopharynx below level of epiglottis: internal branch of superior laryngeal nerve-> vagus nerve
Larynx bellow the vocal cords and trachea: recurrent laryngeal nerve.
6
Q
Which blocks are used for regional Anesthesia for intubation?
A
Glossopharyngeal block:
- local anesthetic sunmucoaally at the caudal portion of the posterior tonsillar pillar.
Superior laryngeal nerve block:
- local anesthetic instilled are the level of the thyroid membrane at the inferior aspect of the greater Cornu of hyoid bone. (Blocks the internal branch of the superior laryngeal nerve)
Transtracheal block:
- recurrent laryngeal nerve blocked by instilling local anesthetic into the trachea at the level of crycothyroid membrane.
7
Q
Landmarks for caudal anesthesia
A
Sacral hiatus - defect formed by failure to S4 and S5 to fuse midline.
Bound by sacral cornu
Sacral hiatus can be found between Posterior superior iliac spines (PSIS).
Pierce through sacrococcygeal ligament.
8
Q
What’s the location of brachial plexus?
A
At or Bellow the level of clavicle.
Closely related to axillary artery.
9
Q
Where is the supraclavicular block performed?
A
Above the clavicle , lateral to the subclavian artery, targeting the brachial plexus.
10
Q
What is meralgia paresthetica?
A
Pain and/or dysesthesia in the anteriolateral thigh.
Caused by compression of femoral cutaneous nerve.
11
Q
Which dermatomes are not adequately covered with iterscalene block?
A
C5-7
12
Q
Intercostobrachial nerve block provide anesthesia to which dermatome?
A
Provides anesthesia to T2 dermatome. Proximal arm.
13
Q
Respiratory centers functions?
Dorsal?
Ventral?
apneustic?
pneumotaxic?
A
Medulla
- Dorsal: ventilation rate by stimulating inspiration.
-Ventral: ends inspiration
Pontine:
- apneustic: sustain inspiration
- pneumotaxic: limits depth of inspiration.
14
Q
Carotid body chemorecptors communicate with respiratory centers via which nerve?
A
Carotid body receptors senses oxygen, CO2, acidosis. Commuicate via glossopharyngeal.
15
Q
Aortic arch chemorecptors communicate with resp centers via which nerve?
A
vagus nerve.
Senses changes in O2, CO2 and pH.
16
Q
whats the function of each pathway:
Dorsal column
Spniothalamic
Corticospinal
Reticulospinal
A
Spinothalamic: carries pain and temperature
Dorsal column: Vibration, propioception, pressure, touch
Corticospinal: Motor fibers
Reticulospinal: Influences motor pathway and is involved in atonomic activity.
17
Q
What is the effect of IV induction anesthetics to CBF? What’s the exception?
A
IV agents decrease CBF.
Ketamine is the exception that increases CBF.
18
Q
What’s the effect of volatile anesthetics to CBF?
A
In general volatile anesthetics INCREASE CBF and decrease CMRO2.
halotane>desflurane>isoflurane>sevoflurane.
19
Q
What’s the effect of nitrous oxide on CBF and CMRO2?
A
If given alone: Increase both CBF and CMRO2.
If given with another volatile anesthetics, Nitrous Oxide effects are exacerbated.
If given with IV agents, has minimal or no effects.
20
Q
What’s the effect of opioids on CBF?
A
Have no effect or decrease.
Remifentanil increases CBF at low sedative rates.
21
Q
What’s the effect of Benzos to CBF?
A
Benzodiazepines reduce CBF.
22
Q
What’s the effect of volatile anesthetics to formation and absorption of CSF?
A
Halotane impedes absorption of CSF, minimal decrease in CSF formation.
Isoflurane facilitates CSF absorption.
23
Q
Where CSF is produced?
Whats the rate of production?
What’s the total volume?
Where is absorbed?
A
Produced by the coroid plexus.
20ml/h
Total volume 100-150mL
Absorbed at arachnoid villi in cerebral venous sinuses.
24
Q
Which IV anesthetic class provides some protection against ischemia?
A
Barbiturates
25
What's the effect of Ketamine on CSF?
Ketamine increases CSF production.
26
Whats the most ubiquitous material in the epidural space?
Fat
27
What it the gate control theory?
Non painful input results in attenuation of the pain sensation.
28
What is the effect of NMDA receptor activation?
Hyperalgesia
opioid tolerance
reduce central sensitization
29
Which drugs are NMDA receptor antagonist?
Ketamine
Methadone
memantine,
amantadine
dextromethorphan
30
activation of which opiod receptor is antipruritic?
Kappa
31
What to do if a vaporizer is tipped on it's side?
Run high fresh gas flows with the dial set to a high concentration for 30 minutes
32
What happen to the output concentration of a volatile
anesthetic from a vaporizer if connected to 100% oxygen?
and 100% Nitrous Oxide?
100% nitrous oxide => decrease in the vaporizer output occurs, as the nitrous is more soluble in anesthetic liquid.
100% Oxygen => output concentration increases.
33
How very low or very high flow rates affects the output concentration of volatile anesthetic from a vaporizer?
Very low rates -> not enough turbulence to pick up the anesthetic vapors.
Very high flow rates => more than 15L/min => the flow is too fast, not enough time to concentrate the gas => will have a lower concentration than what's on the dial.
34
T o decrease temperature fluctuations while delivering an anesthetic agent, manufacturers seek to use vaporizer materials that has which properties?
High specific heat, high thermal conductivity.
Less temperature variability means more stable concentration of volatile anesthetics vapors being delivered to the patient.
35
How to determinate how much time left in Oxygen Cilinder?
Pressure psig/(200 x flow rate).
A 2000 psig cilinder has 625L.
36
What is the definition of critical temperature?
Max temp which a gas can exist in liquid form
37
What does means to say a volatile anesthetic is at equilibrium in blood, CNS and alveoli?
It mean the the partial pressure in the blood, CNS and alveoli are the same.
38
which tissue group plays the greatest role in determining emergence time?
FAT
39
What should be the sequence of flowmeters on the anesthesia machine to prevent hypoxic mixtures?
Oxygen should be always to most downstream flow meter to prevent a backflow.
The sequence would be N2O, Air, O2.
40
What's the function of a valve check on anesthesia machine?
Prevent backflow from the common gas outlet to the vaporizer.
41
What would cause a sudden Co2 decrease on capinography during surgery?
Sudden severe Hypotension, Massive PE, cardiac arrest.
42
Ultrasound sound wave characteristics properties:
Amplitude
Frequency
Wavelength
Velocity
Amplitude: How loud the sound is
Frequency: Number of cycles per second. Lower frequencies penetrate better tissues
Wavelength: Distance between two peaks of each wave
Velocity: product of wavelength and Frequency.
43
Ultrasound resolution:
Axial
Lateral
Elevational
Axial: evaluate objects lying on the axis of the US beam
Lateral: objects horizontal to the beam
Elevational: Objects vertical to the beam
44
How to maximize axial resolution on ultrasound?
Use short high frequency pulses.
Caviat: Has lower penetration.
45
What's the function of a flow proportioning system in an anesthesia machine?
Prevent Hypoxic gas administration.
46
What's Isolated Power System (IPS)?
It's a system that prevents macroshock (enough to cause V fib)
The power supply for the OR is ungrounded and isolated from ground potential.
47
What the most oxygen consuming event in cardiac cycle?
The most energy consuming event in the cardiac cycle is isovolumetric contraction
48
What is the earliest indicators of myocardial ischemia?
The earliest indicators of myocardial ischemia is increased left ventricle end-diastolic volime (LVEDV) and dreased compliance.
49
What is the E and A waves on echocardiography? What is their normal relationship?
E wave: flow across the mitral valve during early diastole. A wave : flow during atrial contraction.
-Normal diastolic function is E to A wave ratio more than 1.
- Diastolic dysfunction: A wave is more proeminent than E wave.
50
How to calculate MAP?
MAP = DBP + (0.33x pulse pressure)
51
What's the effect of inhaled anesthetics to SA node automacity?
Depress SA node automacity.
Prolong conduction and increase refractoriness.
52
Why there is Junctional Tachycardia when anticholinergic is given for sinus bradycardia during inhalation anesthesia?
Inhaled anesthetics depress SA node automacity.
Therefore, anticholinergic stimulate Junctional pacemakers more then SA node.
53
What are the effects of opioids on heart conduction?
Opioids, specially fentanyl and sulfentanil, depress cardiac conduction, increase the time for AV node conduction and refractory period and prolong the duration of Purkinje fiber action potential.
54
What are the effects of Bupivacaine on the heart?
Longer effect then others local anesthetics.
Binds to open or inactivated sodium channels.
Can cause profound sinus bradycardia and sinus node arrest and malignant ventricular arrhythmias.
Can depress ventricular contractility.
55
How to treat local anesthesia systemic toxicity
20% lipid emulsion.
56
What's the effect of volatile anesthestics on cardiac contractility?
Depress contraction due a decrease in Ca2+ entry into cells during depolarization.
57
Which factors can potentiate cardiac depression by volatile anesthetics?
hypocalcemia, B-block, ca channel bloq, Nitrous oxide.
58
What is compound A?
Compound A is a Sevoflurane degradation by-product, known to be nephrotoxic in rats.
59
Which factors increase compound A formation?
Dry barium hydroxide, increased respiratory gas temp, low-flow anesthesia, high sevoflurane concentration.
60
Which are the specific anesthetic considerations for Aortic Stenosis patients?
The patient should be kept with elevated SVR, low HR and optimized preload.
61
Which are the anesthetic considerations for a patient with Pulmonary HTN.
Should maintain right coronary well perfused.
1. High SVR
2. Decrease PVR.
3. increase inotropy.
62
Which medication should be avoided in a transplanted heart?
Neostigmine and other acetylcholinesterase inhibitors should be avoided as it can cause bradycardia dose-dependent. (responds well to atropine).
63
How long should a patient wait to go on a non-cardiac surgery after an MI?
60 or more days.
64
Which induction agent should be avoided in Hypertensive patients?
Ketamine can cause hypertension and should be avoided in HTN patients. Although when given with another agent as opioids or benzos, it's sympathetic effects are blunted.
65
Function
C5-6
C6-7
C8
T1
C8-T1
L2-L3
L3-4
L4-5
L5-S1
S1-S2
C5-6
Arm flexion against resistance (musculocutaneous nerve)
C6-7
Wrist extension against resistance (radial nerve)
C8
Grip strength (median nerve)
T1
Finger abduction (fanning) against resistance (ulnar nerve)
C8-T1
Thumb opposition against resistance (median nerve)
L2-L3
Hip flexion against resistance (femoral nerve)
L3-4
Knee extension against resistance (femoral nerve)
L4-5
Ankle dorsiflexion against resistance (peroneal nerve)
L5-S1
Knee flexion against resistance (sciatic nerve)
S1-S2
Ankle plantarflexion against resistance (tibial nerve)
66
What is the Hering-Breuer reflex?
The slowing of breathing with activation of pulmonary stretch receptors.
67
Neuroleptic malignant syndrome symptoms
Muscle rigidity, trismus, tremor, hyperthermia, altered mental status and autonomic instability.
68
What is the meaning of each letter on a pacemaker? eg. DDD
The first letter means which chamber it paces (A-atrial, V- ventricular, D- dual, O-none).
2nd letter it senses.
3rd letter is the response (I-inhibited, T-trigged, D- Dual, O-none).
4th letter describes programmability (R-rate modulation, O-none).
69
Criteria for biventricular pacing in CHF.
NYHA class III or IV; EF < 35% and QRS > 120msec.
70
When epinephrine should be given in a non-shockable rhythm CPR?
For non-shockable rhythm should be given as soon as possible.
For shockable rhythm calls for defibrillation then 2 min of CPR then defibrillation then epinephrine.
71
What are approved uses for Hyperbaric oxygen therapy?
1. Gas-bubble disease (air embolism and decompression sickness)
2. Carbon Monoxide poisoning.
3. Infections (soft tissue necrotizing infections, intracranial abscess, refractory chronic osteomyelitis.
4. Acute tissue ischemia( crush injury, compromised skin flaps, central retinal artery or vein occlusion)
5. Chronic ischemia (chronic ulcer, radiation necrosis)
6. Acute hypoxia (blood loss anemia and blood can't be given).
7. Acute thermal burn injury,
8. Idiopathic sudden sensorineural hearing loss.
72
Through each muscles the needle goes through on a infraclavicular block?
Pectoralis major and pectoralis minor.
73
What's the level of blockade on a infraclavicular block?
Blocks at the level of the cords and provides analgesia to the arm below shoulder level.
Blocks also musculocutaneous and axillary nerves.
Lateral, medial, and posterior cords are around the the axillary artery. Block is performed depositing local anesthetic around the axillary artery.
74
How to identify C7 on physical exam?
It's the most cephalad stationary spinous process when the patient flexes and extend their neck.
75
What are the normal values for parameters measured with a Pulmonary arterial catheter?
CVP: 2-6mm Hg
PCWP: 6-12mmHg
CI 2.5 - 4L/ min/m2
SVR 800-1200 dynes*sec/cm
76
How is CVP, PCWP, CI and SVR in cardiogenic shock?
CVP: high
PCWP: high
CI: low
SVR: high
77
How is CVP, PCWP, CI and SVR in hypovolemic shock?
CVP: low
PCWP: low
CI: low
SVR: elevated
78
How is CVP, PCWP, CI and SVR in distributive shock?
CVP: low
PCWP: low
CI: high
SVR: low
79
How is CVP, PCWP, CI and SVR in obstructive shock?
CVP: high
PCWP: high
CI: low
SVR: elevated
80
What is the land mark for a lateral femoral cutaneous block?`
Anterior superior iliac spine.
81
Difference between roller and centrifugal pumps in cardiopulmonary bypass?
Centrifugal pumps require flowmeters on the arterial portion, due to flow variation with with alterations in pump preload and afterload.
Roller pump flow depend only on the speed of the rollers.
Roller pump is more associated with blood element destruction, creation of plastic emboli, and elimination of tubing wear and spallation, and inflow and outflow obstruction.
82
What are the most common complications after subarachnoid hemorrhage?
The most common cause of death is the initial bleeding.
Rebleeding peaks in 24h.
Vasospasm starts occurring from the third day, but peaks in 5 to 10 days.
83
What is phosgene? cause of mortality/morbidity? treatment?
Chemical used in warfare. Cause pulmonary damage. Treatment is supportive.
84
Which block is performed for patients with CRPS of the lower extremity?
Lumbar sympathetic plexus block. Injection of local anesthetic at the anterolateral aspect of lumbar vertebral bodies (L1-L5).
85
What is the most common valvopathy associated with rheumatoid arthritis?
Mitral regurgitation.
86
Interscalene block. Indications? Complications
Shoulder, lateral clavicle and upper arm surgeries.
Complications: recurrent laryngeal nerve paralysis, Horner's syndrome, diaphragmatic paralysis, intravascular injection in the vertebral artery, unitentional epidural or subarachnoid block, pneumothorax.
87
Supraclavicular block. Indications? Complications?
upper arm, elbow, and forearm.
Major complication is pneumothorax due to the close proximity to the pleura. And intravascular injection in suprascapular and transverse cervical arteries.
Horner's.
88
Infraclavicular block. Indications? Complications?
upper arm, forearm, and hand.
Level of chords.
Complications similar to supraclavicular, but lesser chance of Horner's and pneumothorax.
Needle goes through pectoralis major and minor.
89
Axillary block. Indications? Complications?
procedures elbow, forearm and hand.
Block of the terminal branches.
Lesser chance of phrenic nerve paralysis or pneumothorax.
90
What are the borders of adductor canal?
Sartorious, vastus medialis, and adductor longus muscles.
91
Adductor canal block indications?
Surgery on the knee and/or cutaneous involvement of the medial leg or ankle.
92
Location of lateral femoral cutaneous nerve?
the lateral femoral cutaneous nerve originates from L2 and L3 and carries
only sensory fibers. The nerve is located inferior and medial to the anterior superior iliac
spine and supplies the anterolateral part of the thigh up to the knee.
93
Duration of local anesthetics:
lidocaine 2% and mepivacaine 1.5% w/ ropivacaine .2% or .5%?
Ropivacaine .2 to .5% solo
lidocaine 2% or mepivacaine 1.5% w/ ropivacaine .2% or .5%? -> 5 to 6h
Ropivacaine alone -> 12 to 14h.
94
CNS signs of local anesthetic toxicity:
Circumoral paresthesias, lightheadedness, dizziness, difficulty focusing, and tinnitus
Restlessness and agitation
Slurred speech, drowsiness, and unconsciousness
Shivering, muscular twitching, tremors, and generalized seizures
Respiratory depression and respiratory arrest.
95
Cardiovascular signs and symptoms of local anesthetic toxicity:
Bradycardia
Hypotension
Intractable arrhythmias (ventricular ectopy, multiform ventricular tachycardia, and
ventricular fibrillation)
Cardiovascular collapse and asystole.
96
Where the spinal cord terminates in infants?
The spinal cord terminates at L3 level, dural sac extends to S3.
97
why bradycardia is uncommon in infants undergoing spinal anesthesia?
Infants have a high vagal tone and immature sympathetic system. Infants do not rely on cardiac accelerating fibers for a resting heart rate.
Bradycardia occurs in adults when sympathectomy affects the cardiac accelerating fibers (T1-t4).
98
Whats the CSF volume ml/kg in infants, children and adults?
Infants 4mL/kg
Children 3mL/kg
Adult 1.5-2mL/kg
99
When a malpractice situation needs to be reported to National Practitioner Data Bank?
Any malpractice payment made by insurer must be reported to NPDB, whether is a pretrial settlement or the result of judgment.
100
What are the most common side-effects of administration of succinylcholine in children?
1. Bradicardia
2. Junctional rhythms
3. Myalgias
4. Hyperkalemia (if patient has muscular dystrophy).
5. Malignant hyperthermia
7. No significant clinical effect: increase ICP, intraocular pressure and intragastric pressure.
101
How to calculate maximum allowed blood loss?
EBV= weight KG x blood volume (ml/kg)
ABL= EBV x(Hct initial - Hct target)/ Hct initial
102
Average blood volumes for:
Premature neonates
Full term neonates
Infants
Adult men
Adult woman
Premature Neonates 95 mL/kg
Full Term Neonates 85 mL/kg
Infants 80 mL/kg
Adult Men 75 mL/kg
Adult Women 65 mL/kg
103
What are the effects to platelets in cirrhotic patients?
Platelets are usually decrease due to hypersplenism and due reduced production of thrombopoietin. Alcoholism can cause bone marrow suppression.
104
What's the pattern on a flow-volume loop for a variable extrathoracic airway obstruction?
Has a plateau on the INSPIRATORY curve
105
What's the pattern on a flow-volume loop for a variable intrathoracic airway obstruction?
Has a plateau on the EXPIRATORY curve
106
What's the effect of NO in the smooth cells of the pulmonary vasculature?
Nitrous oxide activate guanylate cyclase, which converts GTP in GMP.
Increased cGMP causes smooth muscle relaxation.
107
which substance controls the hepatic arterial buffer system?
Adenosine.
Hepatic arterial buffer system, stands for the portal venous flow regulating hepatic artery flow.
Adenosine is produced and accumulated in the liver. When there's reduced portal venous flow, it builds up and causes dilation of hepatic artery.
If portal vein flow is increased, less adenosine is accumulated and causes vasoconstriction of hepatic artery.
108
Which nerve needs to be blocked in addition to supraclavicular block to decrease tourniquet pain?
Intercostobrachial nerve (t2). Medial upper arm dermatome.
Not covered by any brachial plexus blocks.
109
Anterior spinal chord ischemia will effect which evoked potential?
Motor evoked potential.
50% decrease in amplitude and 10% increase in latency.
110
Posterior spinal chord ischemia will effect which evoked potential?
Somatosensory evoked potential.
111
Which opioids should be avoided in CKD patients?
Morphine and meperidine.
Morphine metabolite, morphine-6-glucoronide, is more potent then morphine is excreted by the kidney.
Meperidine metabolite, normoperidine, is neurotoxic and can cause seizure.
112
What are the most common causes of atlantoaxial instability?
1. trauma
2. achondroplasia
3. down syndrome
4rheumatoid arthritis
113
How to manage auto-PEEP?
1. Disconnect the expiratory limb from the ventilator to allow complete exhalation.
2. Adjust vent settings: a. increase expiratory time. b. decrease respiratory rate. c. decrease tidal volume.
3. Reduce demand: reduce pain, anxiety, fever, give sedation/ NMR, reduce dead space.
4. reduce flow resistance: give broncho dilators, suction the tube.
5. increase external PEEP.
114
What's the effect of mu-opioid receptors?
1. miosis
2. dependence
3. respiratory depression
4. sedation
5. nausea
6. euphoria
obs: all opioid receptors have analgesic effects.
115
What's the effect of kappa-opioid receptor?
1. miosis
2. diuresis,
3. dysphoria
116
what's the effect of delta-opioid receptors?
1. respiratory depression
2. inhibits dopamine release
3. modulates mu receptor.
117
On which receptors Nalbuphine works?
Kappa-opioid agonist and partial mu-opioid antagonist.
Has similar analgesic effect as morphine, but has a ceiling effect around 30mg where it does not produce further respiratory depression.
118
Buprenorphine receptors?
Mu-opioid partial agonist and kappa-antagonist.
119
Butorphanol works on which receptors?
Mu-opioid agonist-antagonist and a kappa-opioid receptor partial agonist.
Helps to treat pain, post-op shivering, and neuroaxial opioid-induced central pruritus.
120
How to treat extrapyramidal symptoms caused by antidopaminergic (metoclopramide) medications?
1. Anticholinergic medications (benzotropine, diphenhydramine, atropine).
Second line treatment: benzos, beta-blockers, antihistamines, and dopamine receptors agonist.
121
Which drugs are metabolized by pseudocholinesterase?
Succinylcholine, mivacurium, ester local anesthetics( procaine, chlorprocaine, cocaine, tetracaine), aspirin, and heroin.
122
Which enzyme is inhibited by etomidate?
11B-hydroxylase, which is responsible for synthesis of cortisol and aldosterone.
123
What causes ichemia-reperfusion syndrome?
The ischemia time during the liver transplant causes disruptions on Na-K channels due to lack of ATP and glycogen. When the liver is reperfused, more sodium enters the cell causing swelling and more damage.
124
What's the mechanism behind Cushing reflex?
Increased intracranial pressure, causes increase intramedullary pressure resulting in medullary ischemia. Ischemia of the vasomotor center will cause a increase in systemic vascular tone, myocardial contractility, and heart rate, to improve cerebral perfusion. The increase in vascular tone causes reflex bradycardia mediated by baroreceptors.
125
Why elderly patients have slower onset of NMB and longer duration?
Potency is the same. Slower onset due to reduced cardiac output, therefore takes longer to distribute the drug. Longer duration because most of NMB depends on liver or renal clearance to be eliminated. The exception is cisatracurium which depends on Hofmann elimination.
126
What's the main cause for shortness of breath after interscalene block?
Diaphragmatic hemiparesis, which occurs in 100% of the patients undergoing interscalene blockade.
127
What are the main differences of spinal anesthesia in infants compared to adults?
1. Faster onset due to a higher cardiac output, highly vascular pia mater, and loose myelination.
2. Decreased duration of action, due to increased diffusion and clearance.
3. increased spread due to a lack of thoracic kyphosis.
4. Cardiovascular collapse is rare, because their sympathetic system is immature, so they don't depend on it.
128
Factors that promote leftward-shift of hemoglobin-oxygen dissociation curve?
1. CO poisoning
2. hypothermia
3. Hypocapnia
4. reduced concentration of 2,3 BPG.
5. Alkalemia.
129
What are the potential side-effects of rapid administration of thyroglobulin?
1. Fever
2. Anaphylaxis
3. non-cardiogenic pulmonary edema
4. Cardiopulmonary collapse
130
What are the most common early findings of digoxin toxicity under general anesthesia?
Atrioventricular nodal block and frequent ventricular ectopy.
131
What are the advantages of On pump CABG vs off pump CABG?
1. decreased incidence of low cardiac output syndrome
2. decreased length of ventilation, hospital stay, cost.
3. Decreased infection
4. Decrease incidence of stroke
5. Decrease requirement of blood
6. Higher incidence of repeat revascularization within 30 days.
obs: No diference in mortality.
132
When does the INR peaks after donor hepatectomy?
INR peaks between 1- 3days. Goes back to normal 5-7 days. Patients can also have mild thrombocytopenia.
133
What are alternate ways succinylcholine can be administered during laryngospasm?
If no IV access, succinylcholine can be given intramuscular, intralingual, intraosseous, submental.
134
What are the key differences in pulmonary function on a neonate?
1. Lower lung compliance
2. Increased chest wall compliance
3. Pliable rib cage, causing retractions, making gas exchange less efficient.
4, Diaphragm muscles are 25% type I (red, oxidative). In a adult that would 55%.
5. Underdeveloped intercostal muscles - diaphragm as the main responsible for gas exchange.
135
What happens when ondansetron is mixed with dexamethasone?
The preservative in the dexa will cause ondansetron to precipitate out of the solution.
136
What happens when diclofenac and warfarin are mixed?
They both bind to the same site on albumin and can increase the warfarin clinical effect.
137
What happens when propofol and lidocaine are mixed in the same syringe?
Will cause layering and coalescing of the soybean oil and egg lecithin.
138
What are the post-herpetic neuralgia risk factors?
1. old age
2. immunosuppression
3. autoimmune disease
4. Chronic diseases as COPD and CKD.
139
What's the treatment for post-herpetic neuralgia?
1. Tricyclic antidepressants
2. gabapentin
3. pregabalin
4. opioids
5. topical capsaicin
6. topical lidocaine.
140
Compared to sevoflurane, propofol is more likely to suppress which respiratory reflex?
Laryngospasm.
141
What is the Haldane effect?
the process of oxygen binding to hemoglobin and displacing carbon dioxide, which will result in a carbon dioxide dissociation curve.
142
What are the goals of initial management of intracranial hemorrhage?
1. SBP less than 140 - can be done rapidly.
2. Correction of any coagulopathy, including patients on anticoagulants for any reason.
143
When chest compressions should be started on a patient with a LVAD in cardiac arrest?
If a LVAD patient goes into cardiac arrest, blood pressure should be measured, if MAP <50 or ETCO2 <20, chest compressions should be started.
144
5 H and 5 T for arrest
1. Hypoxia
2. Hypovolemia
3. H+ (acidosis)
4. Hypo/hyperkalemia.
5. hypothermia
1. Toxins
2. Tamponade
3. Thrombus - heart
4. thrombus - lung
5. tamponade.
145
Ultrasound is frequency above which range?
20,000 cycles per sec.
146
What is Alvimopan?
Mu-opioid receptor antagonist that does not cross brain-blood barrier used to prevent post-op ileus if patient is using opioids.
147
What's the main cause of acute cardiopulmonary decompensation after curettage/ evacuation of molar pregnancy?
Trophoblastic embolization.
148
In what body temperature range there is complete suppression of EEG activity?
between 15-18 degrees C.
149
What's the main function of a respirometer?
Measures flow in one direction. Attached to expiratory limb of the machine to measure tidal volume and minute ventilation.
150
Which anesthetic gas causes most frequently emergence delirium in children?
Sevoflurane.
Sevo> Des> Iso
151
Which opioid is associated with prolongation of QT interval?
Methadone.
152
From which nerve roots is composed the lateral femoral cutaneous nerve?
L2-L3
153
Signs of propofol toxicity?
Bradycardia, metabolic acidosis, fatty liver, rhabdomyolysis.
154
What are the differences between retrobulbar and peribulbar block?
Retrobulbar injects local behind the eye. Peribulbar around the eye.
Retrobulbar has a quicker onset, longer duration, provides better anesthesia and akinesia. But has more risk of intravascular and intradural injection and retrobulbar hematoma.
155
What are the hematologic effects of Nitrous Oxide?
Nitrous Oxide inactivates irreversibly vitamin B12.
Vitamin B12 is a cofactor on conversion of homocysteine to methionine, which is essential for DNA repair.
Nitrous increase levels of homocysteine.
156
To which site Calcium binds to for muscle contraction?
Troponin C
157
What is the mechanism of the local anesthetic blockade during intravenous regional anesthesia?
Vascular spread to distal peripheral nerves.
158
Celiac plexus provides innervation to which organs?
1. Pancreas
2. Stomach
3. Liver
4. Kidneys
5. Adrenal glands
6. Spleen
7. Diaphragm
8. Small bowel
7. Large intestine up to transverse colon.
159
What are the most accurate sites for monitoring core temperature?
1. Distal esophagus.
2. Nasopharynx
3. Tympanic membrane
4. Pulmonary artery catheter.
160
What's the main finding on a neck radiography of a patient with laryngotracheobochitis?
Steeple sign: Subglottic narrowing on airway column.
161
If a sevoflurane variable pressure vaporizer is filled with isoflurane and the dial is set to 2%, what's the volume percentage of isoflurane is being delivered to the patient?
3.4%
Sevoflurane has a lower saturated volume pressure : 160
Isoflurane SVP is 241mmHg.
Higher the SVP, higher the partial pressure, higher is the volume of gas leaving the chamber.
162
What's the mechanism for pain caused by LOCALIZED pancreatic cancer.
Substance-P secretion from pancreatic afferent nerve.
163
What structure is important in relieving airway obstruction during jaw thrust manuever?
Genioglossus muscle
164
What's the percentage risk of transmission of HIV, HBV, HCV after skin puncture in health care setting?
HIV: 0.3%
HCV: 0.5%
HBV: 30% - if the professional is not vaccinated.
165
What are the risks associated with laser in the OR?
1. Retinal damage
2. Gas embolism
3. Laser Plume
4. Fires
166
What is autonomic hyperreflexia?
Intense sympathetic response below the level of spinal cord injury due to surgical stimulation.
1. Hypertension
2. reflex bradycardia
3. cardiac arrythmias
4. myocardial infarction
5. Headache / seizure due to HTN
6. Vasoconstriction of lower extremities causes dry, pale skin below the SCI level.
7. Reflex vasodilation above the level of injury causes nasal congestion, diaphoresis, flushed skin on upper extremities.
167
What's the most common indication for retrograde cardioplegia?
Aortic insufficiency.
168
Which conditions can increase the B1 receptors density in the myocardium?
1. chronic B-blocker use
2. Hyperthyroidism
3. Myocardial ischemia
169
What's a MAZE procedure?
Open surgical technique that is the most effective means of rhythm control in patients with Afib. It requires full-thickness incisions of both atria and cardiopulmonary bypass.
99% success rate
170
What are the normal values for a TEG?
Rule of 6:
R time approx 6 min
Alpha angle 60 degrees
MA 60mm
Ly30 6%
171
What are the 4T for diagnosis of HIT (heparin induced thrombocytopenia)?
1. Thrombocytopenia
2. Timing of reduced platelet count
3. Presence of thrombosis
4. Exclusion of other causes for thrombocytopenia.
172
How to calculate gas volume output from a vaporizer?
Outflow= inflow *SVP/ATM-SVP)
Quick tip:
SVP/(ATM-SVP) is 1/4 for sevo; 1/2 isoflurane and halothane.
173
What's the main cause for allergic reaction to local anesthetics?
Allergic reactions are mostly to preservatives then to local anesthetic it self, specially for aminoamides.
Aminoester is degraded in para-benzoic acid, which is more associated with allergic reaction.
174
What is the best predictor of oxygen desaturation when initiating one lung ventilation?
Low PaO2 during two-lung ventilation.
175
What's the main advantage of peritoneal dialysis over hemodialysis?
Patients with unstable angina may not tolerate the quick fluid shift with hemodialysis. Peritoneal is a better solution for them.
176
Contra-indications to intra-aortic balloon pump?
Severe aortic insufficiency, aortic disease (dissection, aneurysm), severe peripheral vascular disease.
177
Indications for intra-aortic balloon pump?
Cardiogenic shock
Failure to wean from CBP
Severe mitral regurg
Bridge to transplant or VAD
right ventricle dysfunction.
178
What's the cause of seizure right after stellate ganglion block?
Vertebral artery injection
179
What's the hemodynamic goals for treatment of aortic insufficiency?
Fast, Full, and forward.
Avoid bradycardia, Reduce afterload (SVR), minimize cardiac depression.
Avoid beta-blockers.
180
What are the main bacteria associated to early-onset (48-72) ventilator acquired pneumonia?
1. Methicillin sensitive Staph aureus, Haemophilus influenza, and streptococcus pneumoniae.
can also be due to Proteus, enterobacter, klebsiella.
181
Opioid with fastest ONSET of action?
Alfentanyl -> Sulfentanyl -> Fentanyl -> Morph/hydromorphone.
Onset depends on pKa and liposolubility.
Alfenta pka is 6.8/ Sulfenta in 8/ Fentanyl 8.4/ morph 7.9
Liposolubility: Sulfenta > fenta > alfenta > morph
182
Which arteries are responsible for spinal cord perfusion?
1 Anterior spinal artery (75% of blood flow)
2 posterior spinal arteries (25% of blood flow)
183
Which nerve is the afferent limb of the laryngospasm reflex?
Internal branch of the superior laryngeal nerve.
184
Which drugs DOES not cross the placenta?
neuromuscular blockers, glycopyrrolate, heparin, insulin.
185
Which neurotransmissiors are inhibitory?
Glycine and GABA.
186
What's the cause of ST-T elevations on ECG after subarachnoid hemorrhage?
Catecholamine release.
187
What are the symptoms of epiglottitis? which bacteria causes it? Xray image?
4 D's: dysphonia, dysphagia, dyspnea, and drooling.
thumb print sign on xray
Stepto pneumoniae, S. pyogenes, S. aureus, Haemophilus influenzae.
188
Croup signs and symptoms. Cause?
(laryngotracheobronchitis)
Low-grade fever, barking cough, viral prodrome.
Steeple sign - subglotic narrowing
Parainfluenza virus
189
Why metoprolol is contra-indicated in acute right ventricular failure?
Metoprolol is contraindicated in acute HF or cardiogenic shock due to decrease in inotropy.
190
Which medication has the greatest potential to interfere with microelectrode reading during stereotactic placement of deep-brain stimulation for Parkinson disease?
Midazolam and other benzos.
Propofol also reduce the readings, but is easily titratable and widely used for sedation.
191
What's the most sensitive test for Heparin induced thrombocytopenia?
Platelet factor 4.
obs: Serotonin release essay is to most specific.
192
What are the unique features if ketamine when compared to the other IV anesthetics?
1. preserved airway and respiratory reflexes.
2. significant analgesia
3. increased sympathetic tone.
193
What's the chi-squared test?
Used to compare multiple groups of a categorical data.
194
What's ANOVA test?
test used to evaluate 3 or more groups of parametric data (normally distributed data).
195
What's paired t-test?
test to evaluate 2 paired groups of parametric data.
196
What's the most common finding on ECG after multiple blood transfusions?
Prolongation of QT due to hypoCalcemia, which prolongs repolarization.
197
What are the symptoms of carcinoid syndrome?
flushing, bronchoconstriction, gut hypermobility, hyperglycemia, abdominal pain, hemodynamic instability, dysthymia.
198
In infants, during a single-shot caudal epidural block with ropi 02.%, what's the dose for covering:
sacral dermatomes?
low thoracic dermatomes?
mid-thoracic dermatomes?
sacral dermatomes 0.5mL/kg
low thoracic 1mL/kg
mid thoracic 1.25mL/kg
199
How long after enoxaparin a neuroaxial block can be done?
Prophylactic dose: 12hours
Therapeutic dose: 24h.
200
What's the maximum dose of lidocaine during a tumescence liposuction?
55mg/kg
201
What's the volume used for initial pediatric resuscitation and which fluids are used?
20 cc/kg. NS, LR, Plasmalyte.
202
Magnesium toxicity symptoms at
7-12
>12
>15mg/dL
7-12: Absent tendon reflexes, bradycardia, somnolence, hypotension, prolonged PR, prolonged QRS and QT interval
>12: Muscle paralysis, respiratory failure, complete heart block
>15: Cardiac arrest.
203
What's the most effective medication to prevent post-op nausea and vomiting in children?
Ondansetron.
204
What's the electrolyte abnormality expected with Amiloride?
Hyperkalemia.
It's a potassium sparing diuretic.
205
How to calculate urinary anion gap and what's it's normal value?
uNA+uK-uCL= Anion gap
normal: 0-5.
206
Which syndrome is associated with low serum potassium, acidosis and high urinary anion gap?
Type 1 (distal) renal tubular acidosis. Patient fail to secrete H+ in the urine.
207
At which PaO2 level will the hypoxic respiratory drive increase the respiratory rate?
below 50mmHg. Carotid bodies mediate that
obs: The main driver for ventilatory rate is PaCo2.
208
Which medications are used for stimulating seizures during a craniotomy?
Etomidate, sulfentanil, alfentanil.
209
what are the main differences of a infant airway compared to a adult airway?
1. More cephalad larynx (c3-c4)
2. short omega shaped epiglotis.
3. larger tongue
4. angled vocal cords.
5. larger head.
the most narrow are in infant airway is the glotis.
210
Which factors predict success for epidural steroid injection for lumbar radiculopathy?
1. Acute symptoms
2. Absence of psychopathology
3. Herniation with nerve root irritation or compression.
4. NO previous lumbar surgery.
211
what's the use of T-test?
Compare 2 different means.
212
Which drugs can potentiate the effect on nondepolarizing neuromuscular blocker?
1. inhaled anesthetics
2. Acute use of phenytoin
3. Hypothermia
4. Aminoglycosides.
5. Magnesium
6. Lithium
7. Local anesthetics.
213
Which drugs/clinical scenarios reduce effect of nondepolarizing neuromuscular blocker?
1. Burn victim
2. Corticosteroids
3. Chronic phenytoin.
214
What's the most significant risk factor for emergence delirium?`
Age of the patient
specially children between 2 and 6 years of age.
215
What are the most common findings after starting TPN?
Hyperglycemia, hypercarbia, hypophosphatemia.
can also hepatic steatosis, thrombophlebitis, hypokalemia, hyperinsulinemia, hypomagnesemia.
216
On what period a infant has physiologic anemia?
between 8 and 12 weeks.
217
What is Aprepitant?
It's a anti-emetic that works on NK1 receptor.
218
Which IV anesthetic is contraindicated in pancreatitis patients?
Propofol.
Propofol can cause hypertriglyceridemia, which can worsen/cause pancreatitis.
219
What is the gold standard agent for induction for electroconvulsive therapy?
Methohexital because it does not change seizure duration.
220
Which drugs are more commonly associated with Acute intermittent porphyria attack?
Barbiturates
etomidate
benzos
alcohol
ropivacaine
sulfonamides
lead
221
Which factors are related to increased risk during pediatric sedation?
1. Air-way procedures (bronch)
2. Age < 3 months
3. Use of multiple drugs
4. ASA of 3 or more
5. Obesity
222
What are the laboratorial findings in rhabomyolisis?
1. Hyperkalemia
2. Hypernatremia
3. Hypocalcemia
4. hypoalbuminemia
5.. Hyperuricemia
6. Metabolic acidosis.
223
What are the complications of lumbar sympathetic block for CRPS?
1. Failure to ejaculate (dependent on sympathetic system)
2. Intrathecal, intravascular or epidural injections.
224
What are the risk factors for continued mechanical ventilation in for thymectomy in Myasthenia gravis patients?
1. disease duration > 6years
2. chronic respiratory illness.
3, Pyridostigmine dosage ? 750 mg/day
4. Vital capacity <2.9L
5. Bulbar involvement
6. BMI>28
7. Prior myasthenic crisis..
8. pulmonary resection.
9. antibody title >100
10. Blood loss > 1L.
11. More pronounced decremental response 20% on repetitive stimulation.
225
What's the proper approach to landmark guided IJ cannulation?
insert the needle lateral to the carotid pulse, on the medial border of the lateral head of sternocleidomastoid muscle, angled toward the ipsilateral nipple.
226
What's the advantage of double-burst stimulation compared to TOF?
Better tactile and visual detection of neuromuscular function.
227
What's the treatment for acute spinal cord injuries?
1. MAPs > 85mmHg for the first 7 days.
2. Hgb >10
3.
228
What's seen on EEG on general anesthesia?
Slow-frequency and large-amplitude - similar to REM sleep.
229
Lung physiology - what doesn't change on third thrimester?
1. FEV1
2. Vital Capacity
3. Closing capacity
230
respiratory physiology - what increases in third trimester of pregnancy?
1. inspiratory capacity increases by 15%
2. Tidal volume increases bt 45%
3. Inspiratory reserve increase by 5%
4. minute ventilation by 45%
231
respiratory physiology - what decreases in third trimester of pregnancy?
1. residual volume by 25%
2. expiratory reserve decrease by 25%
3. FRC decrease by 20% (400-700cc)
232
What means ED95 for nondepolarizing neuromuscular blocker?
It's the Effective dose that will cause 95% twitch suppression in the 50% of the population.
233
What is precurarization?
It's when 10% of ED 95 of rocuronium is given 3-5 minutes before succinylcholine to avoid fasciculations.
234
Maternal oxygen consumption is increase by what percentage during second stage of labor?
75%.
first stage is 40%
235
What's the mechanism of non-hemolytic febrile reaction from transfusions?
native host antibodies binds to donor leukocytes (HLA) in the transfused blood.
236
Which patients are high risk for venous thromboembolism in perioperative setting?
1. major lower extremity arthroplasty
2.recent stroke <1month
3. spinal cord injury
4. multiple trauma
5. fracture of hip, pelvis, or lower extremity.
those patients should receive pharmacological prophylaxis w/ heparin and mechanical, except for spinal cord surgeries and major trauma surgeries with risk of bleeding.
237
What's the best anesthetic method for emergent c-section on pre-eclampsia patient?
IV induction with propofol, succinylcholine and nitroglycerin.
Besides propofol and NMB, patient may need a antihypertensive medication and nitroglycerin, esmolol, remifentanyl.
238
What is the treatment for negative pressure pulmonary edema?
1. supportive care - relief of airway obstruction.
2. PEEP
3. Diuretics
239
What's the NYHA classification for HF?
I: activity not limited by HF symptoms
II: Activity somewhat limited
III: Exercise is limited by dyspnea during modest exertion
IV: Dyspnea at rest or with minimal exertion.
240
What's the ACC/AHA HF stages?
A: risk factors for HF
B: Asymptomatic HF
C: Symptomatic HF
D: Refractory End-Stage HF
241
how to calculate the alveolar gas equation?
PAO2= FiO2 (PB-PH20)- PCO2/RQ
PAO2: alveolar oxygen partial pressure
FiO2= fraction of inspired o2
PB= atmospheric pressure 760
PH2O= vapor pressure of water 45
PCO2=
RQ= respiratory quotient 0.8
242
How to treat hypermagnesemia?
1. stop the mag infusion
2. Temporize with calcium
3. Increase the elimination with loop diuretics and normal saline.
243
When to suspect of subcutaneous emphysema during laparoscopic surgery?
Sudden rise in the ETCO2 after initial elevation that happens with insufflation.
244
How lithium interacts with nondepolarizing NMB?
Potentiates paralytics by interfering with prejunctional neuron action potential transmission.
245
What type of pain benefits the most with spinal cord stimulators?
Neuropathic pain.
246
What's the primary mechanism of action of epinephrine during a cardiac arrest?
Alpha-1 agonism.
It increases blood pressure and restores coronary perfusion.
247
What's the mechanism of action of pregabalin?
Voltage-gated Ca2+ channel blockade, preventing the release of nociceptive neurotransmitters.
248
How does Acetaminophen causes hepatocellular injury?
After phase 1 hepatic metabolism, it's converted in n-acetyl-p-benzoquinone (NAPQI) which is toxic. APAP is conjugated with glutathione in phase 2.
If OD of Tylenol, glutathione stores are depleted and NAPQI accumulates, resulting in mitochondrial injury.
249
What is associated with a large difference between peak and plateau pressure?
Suggestive of high resistance.
Bronchospasm, kinked endotracheal tube, and mucus plug.
Plateau pressure is the alveolar pressure.
250
What is associated with high peak pressures and high plateau pressures, with a small difference between them?
Poor compliance, poor positioning, pulmonary fibrosis, pneumothorax, obesity, or chest wall deformity or compression.
251
What's the mechanism of action of midazolam?
Positive allosteric of modulator of the GABAa receptor.
252
What are the complications associated with transcutaneous pacing?
Discomfort
muscle injury
rhabdomyolysis
hyperkalemia
253
Which antiemetic does not reduce the risk of PONV when given in combination with ondasetron?
Metoclopramide.
Although it works alone, when given in combination with another antiemetic, it doesn't reduce further the risk of PONV.
254
What's the advantage of subglottic jet ventilation in comparison to SUPRAglotic jet ventilation?
Ability to assess end-tidal carbon dioxide.
255
How abdominal insufflation causes an increase in SVR and BP?
Reduced splanchnic blood flow, stimulate vasopressin release which cause renin-angiotensin -aldosterone system activation and increase in SVR and MAP.
256
How is the response to neuromuscular blockers in Eaton labert?
Lambert-eaton patients are sensitive to both succinylcholine and NDNMB.
257
How is the response to neuromuscular blockers in myasthenia gravis?
Myasthenia gravis patients are sensitive to nondepolarizing neuromuscular blockers and are RESISTENT to succinylcholine (less receptors to attach to).
258
What's the main cause of stridor 24h after total thyroidectomy?
Hypocalcemia.
259
Which anesthetic is safe to minimize the risk of postop hepatic encephalopathy?
Propofol.
It does not decrease hepatic blood flow.
260
What are the anesthetic considerations on a patient with Atrial septum defect who is symptomatic (dyspnea).
Symptoms derive from pulmonary HTN.
1. Maintain HR, contractility, Cardiac output
2. Avoid increase in PVR relative to SVR.
(avoid peep to not increase SVR, avoid hypercapnia).
3. Patient will be at risk for arrhythmias post-bypass from the patch closure.
261
What's the most appropriate management of a DM1 patient on insulin pump going for ex-lap after major trauma?
Stop the insulin pump, start insulin IV infusion and measure glucose levels every hour.
262
What's the leading cause of perioperative mortality in the morbidly obese patients?
Deep venous thrombosis.
263
Which local anesthetic has the lowest placental transfer after epidural route?
Chloroprocaine.
Quickly metabolized by plasma cholinesterase.
264
Up unitil what postconceptual (corrected) age is it prudent to minitor neonates overnight following GA?
60 weeks.
Up to 60 weeks increase risk of bradycardia and apnea.
265
What are the effects of hyperoxia?
1. peripheral vasoconstriction
2. Pulmonary vasodilation - can cause intrapulmonar shunt.
3. Excessive oxidative stress.
266
What's the treatment/management for venous air embolism during craniotomy?
1. Hemodynamic support (epinephrine)
2. stop air entrainment: Flood the field with saline, bone wax applied to exposed bone, surgical site lowered below the level of the heart.
3. increase in PEEP and compression of jugular vein can be attempted.
4. Removal of air with central line is rarely successful in pedi patients
267
How much fibrinogen one unit of cryoprecipitate has?
200mg/unit.
268
which methods are indicated to detection of venous air embolism?
1.TEE
2. Precordial doppler
3. PAC
4. TCD
5. ETCO2
6. ECG
269
What are the main considerations for Becker dystrophy?
1. Mutation of dystrophin gene with reduction of protein dystrophin.
2. Epilepsy
3. Macroglossia
4. color blindness
5. Cardiac involvement.
270
What's the mechanism of action of phenytoin?
Alteration of sodium conductance in motor neuros by either promoting sodium efflux or inhibiting sodium influx.
271
What are the signs of bone cement implantation syndrome?
hypoxia, hypotension, cardiac dysrhythmias, and increased pulmonary vascular resistance.
unknown mechanism.
272
What is the preoperative test most accurate predicting kidney injury in setting of suprarenal cross-clamping for repair of a ruptured abdominal aortic aneurysm?
Creatinine clearance.
273
How to calculate SVR?
SVR=80x(MAP-CVP)/CO
274
What's the major hurdle to determining optimal treatment for phantom limb pain?
Lack of randomized clinical trials.
275
What's the mechanism of hepatic encephalopathy in patients with acute liver failure?
It's cerebral edema caused by the conversion of ammonia to glutamine within astrocytes, resulting in fluid shift in the brain.
276
Which muscles opens the true vocal cords?
Posterior Cricoarytenoid muscles- innerved by recurrent laryngeal nerve.
277
What are the signs and symptoms of postdural puncture headache?
Headache within 6 to 72 after dural puncture. Associated with nausea, stiffness of the neck, photophobia, difficulty in accommodation of vision and diplopia, tinnitus and hearing loss.
278
What's the difference between pH-stat and alpha-stat?
Both are methods of managing acid-base status during cardiopulmonary bypass.
CBP -> hypothermia -> reduce Cerebral metabolic demand.
Hypothermia -> alkaline drift -> increase in gas solubility -> reduce PaCo2.
pH-stat: maintain neutral pH during hypothermia by adding CO2 to CBP.
increased PaCO2 -> cerebral vasodilation-> increased CBF-> increased cerebral cooling and oxygen delivery..
Increased CBF can cause increased delivery of embolic load.
alpha-stat: alkaline drift without correction.
279
What's the reason for giving a vasoconstrictor for preparation of the nasal mucosa during nasal fiberoptic intubation?
Increase diameter of the nasal passage.
280
What's the reasoning for reduced dosing of local anesthetics through epidural in elderly patients?
Increased dura permeability
281
Which factor can cause a overestimation of Cardiac output using thermodilution?
Thermodilution measures CO by detecting the rate of change in temperature. Lower the change, higher the CO.
- If the injectate is 9mL instead of 10mL
- If the injectate is given a room temp instead of iced.
282
What's the best diagnostic test for DIC in patient with End Stage liver disease?
Factor VIII.
It's usually not affected by ESLD or it's increased. If it decreases in setting of suspected DIC, it confirms the diagnosis.
283
Which test is the best determinant of synthetic function of the liver?
PT/INR
It measure extrinsic coagulation pathway which involves factor VII.
Factor VII has a half-life of 4-6 hours.
284
What's the effect of hypercalcemia on non-depolarizing neuromuscular blockers?
Antagonizes NDNMB effects.
285
What's the most common adverse event during pediatric sedation?
hypoxia.
286
What's the sodium content in albumin 5%?
145+-15.
287
Where is the stellate ganglion located?
Stellate ganglion represents a fusion of inferior cervical and first thoracic sympathetic ganglion. Located anterior to the neck of first rib and just anterior to transverse process of C7.
288
What's the effect of volatile anesthetics at >1 MAC of CBF and CMRO2?
It increases CBF and decreases CMRO2. "uncoupling"'
289
Which volatile anesthetic has the lowest vapor pressure? and the highest?
Sevoflurane has the lowest vapor pressure and Desflurane has the highest.
290
How does TENS works?
Inhibits A-delta and C pain fibers.
Works better for myofascial pain.
It's effects can be reversed by naloxone.
291
How long postpartum does the cardiac output return to normal?
2 weeks
292
How is the adrenergic response in pregnant patients?
The effect of adrenergic agents and vasopressors is blunted during pregnancy.
SVR is reduce with term progression.
293
What are the hemodynamic effects of aortic cross-clamping?
1. Increased arterial BP above the level of the clamp
2. Increased coronary artery blood flow.
3. Increased left ventricular wall stress.
4. Increased central venous pressure.
5. Increased pulmonary artery wedge pressure.
6. Decresd arterial BP below the clamp.
7. Decreased CO
8. Decreased renal blood flow.
294
Which area of the spinal cord is sent electrical impulses from a spinal cord stimulator?
Dorsal columns
295
what O2 pressure, the O2 pressure -shutoff valve requires to remain open and allow N2O to flow into the N2O rotameter?
30 PSI
below this pressure, the N2O valve is shutoff to avoid hypoxic mixture.
296
The second-stage O2 pressure regulator delivers a constant
O2 pressure to the rotameters of
16psi
297
The highest trace concentration of N2O allowed in the
operating room (OR) atmosphere by the National Institute
for Occupational Safety and Health (NIOSH) is
25
298
According to NIOSH regulations, the highest concentration
of volatile anesthetic contamination allowed in
the OR atmosphere when administered in conjunction
with N2O is
0.5ppm
299
The device on anesthesia machines that most reliably
detects delivery of hypoxic gas mixtures is the
o2 analyzer
300
What's the function of first stage oxygen regulator?
shut-off the lower pressure o2 tank when the higher pressure pipeline is sensed.
301
Why the intubation dose of neuromuscular blocking agents should be increase in cirrhotic patients?
Due to increase in volume of distribution.
302
What's part of the Alderete score?
It's a post anesthesia score for PACU.
Take under consideration
1. activity
2. breathing
3. circulation
4, consciousness
5 Saturation.
303
what's a, c, x, v, y on CVP curve?
a: atrial contraction
a->c: ventricular systole starts
c= tricuspid valve closes
x= early systole
v= right atrial filling -> diastole starts
y= right ventricle starts filling
304
How much fibrinogen there's in one unit of cryoprecipitate?
200mg
305
What surgery is mostly associated anterior ischemic optic neuropathy?
and posterior ION?
Cardiac surgery is associated with AION
Spine surgery is associated w/ PION
306
how to calculate static compliance?
Cs= Vt / (Ppl-Peep).
307
how to calculate dynamic compliance?
Cd= Vt / (Peakp - peep)
308
At what level the dural sac ends in adults?
S1-S2
309
Why hypermagnesemia cause muscle weakness?
Decreased release of acetylcholine (presynaptic calcium channel blockade and end plate sensitivity to acetylcholine.
310
At what Mg levels there is EKG changes? PR prolongation and QRS widening?
6-12 mg/dL. Mg causes calcium channel blockade.
311
Which upper extremity nerve block has the highest risk for pneumothorax?
Supraclavicular block.
312
What is the most common side effect when you are giving a second dose of succinylcholine?
Bradycardia, specially in children due to a higher vagal tone.
Succinylcholine cause activation of muscarinic receptors on sinoatrial node.
313
From which spinal level does the great radicular artery most commonly originate?
Thoracic 9-12
314
Which block sites in order has the greatest to least anesthetic systemic absorption
Intercostal> caudal> epidural> interscalene> femoral
315
What's the best Mapleson circuit for Controlled ventilation?
Mapleson D w/ Bain modification.
FGF required is only 1 to 2 times the MV.
316
What's the Urine osmolarity vs serum osmolarity ration that indicates pre-renal oliguria?
OsmU:OsmP > 1.5
therefore if plasma Osm is 294, Urine Osm needs to be 441.
317
What kind of medication is Nesiritide?
Recombinant form of brain natriuretic peptide that causes vasodilation, diuresis, and natriuresis.
318
What receptors is a excitatory glutamate recepor?
NMDA receptors.
Ketamine blocks NMDA receptors.
319
What factors are in cryoprecipitate?
vWF, fibrinogen, factor VIII, and factor XIII
320
What are the effects of Post opertative hyperglycemia?
Immunosuppression, increased infections, delayed gastric emptying, sympatho-adrenergic stimulation, and increased mortality.
321
Which mechanism provides analgesia with tricyclic antidepressants?
Antagonism of central alpha receptors.
