Questions Flashcards
1
Q
Best intra-op anticoagulation for pt undergoing cardiac surgery with cardiopulmonary bypass with Heparin Induced Thrombocytopenia type 2?
A
Bivalirudin
2
Q
Potential complication of TAP block?
A
Local anesthetic systemic toxicity
3
Q
Best predictor of difficult intubation?
A
Class 3 upper lip bite test- cannot bite upper lip with lower incisors
4
Q
What is a rare complication of high lumbar spinal anesthesia involving the conus medullaris, and what are its symptoms?
A
Conus medullaris injury, causing sensory and/or motor deficits in multiple nerve distributions, either unilateral or bilateral.
5
Q
What is an absolute contraindication for percutaneous tracheostomy in infants?
A
Subglottic stenosis.
6
Q
In a mid-esophageal aortic valve short axis view (ME AV SAX), which aortic cusp is located next to the inter-atrial septum?
A
The non-coronary cusp.
7
Q
What conditions are associated with malignant hyperthermia (MH)?
A
King-Denborough syndrome, central core disease, and multiminicore disease are associated with MH, and they include RYR1 mutations. Masseter muscle rigidity is also linked to MH.
8
Q
What cardiovascular effects can dexmedetomidine cause, especially with a loading or bolus dose?
A
Dexmedetomidine can cause bradycardia, hypotension, and hypertension.
9
Q
What is the mechanism of action of phenytoin?
A
Alteration of sodium conductance in motor neurons.
10
Q
What is the most common cause of adrenal insufficiency in patients with critical illness in the intensive care unit?
A
Functional adrenal insufficiency
11
Q
Which serum electrolyte is decreased in DKA?
A
Sodium (due to hyperglycemia shifting water out of cells)
12
Q
Hypoglycemic patient who is confused/not alert or sedated but has IV access, next step in management?
A
IV dextrose
13
Q
Hypoglycemic patient who is confused/not alert or sedated and has NO IV access, next step in management?
A
IM glucagon
14
Q
Hypoglycemic patient who is alert and can tolerate liquids, next step in management?
A
oral glucose
15
Q
most common cause of hydrocephalus?
A
chiari malformation
16
Q
what is the only organ innervated by cholinergic post-ganglionic sympathetic neurons?
A
sweat glands
17
Q
What happens when crystalloids rather than colloids are used for fluid resuscitation?
A
Crystalloids result in greater peripheral edema.
18
Q
which drug is associated with triggering a carcinoid crisis?
A
succinylcholine
19
Q
what should be avoided as treatment of hypotension in in a pt with HOCM?
A
inotropes and vasodilators
20
Q
What is the most common cause of an acute change in peak airway pressures and desaturation when a bronchial blocker is used for one-lung ventilation?
A
Dislodgement of the bronchial blocker, leading to occlusion of the trachea or the mainstem bronchus of the ventilated lung.
21
Q
What is Fisher Grade 1?
A
no blood detected
22
Q
What is Fisher Grade 2?
A
diffuse thin layer (<1 mm) of subarachnoid blood
23
Q
What is Fisher Grade 3?
A
localized clot or thick layer (>1 mm) of subarachnoid blood
24
Q
What is Fisher Grade 4?
A
intracerebral or intraventricular blood with diffuse or no subarachnoid blood
25
What prolongs the seizure duration for ECT and has a safe hemodynamic profile?
Etomidate
26
what is the gold standard induction agent for ECT?
methohexital
27
which medication is associated with myoclonus?
etomidate
28
what is the pH and lactate of fetal acidosis?
pH <7.21 or lactate >4.8
29
what is the advantage of subglottic jet ventilation compared to supraglottic jet ventilation?
decreased contamination of the airway
30
after bicuspid aortic valves, what is the most common congenital heart defect?
perimembranous ventricular septal defect
31
which electrolyte abnormalities are associated with citrate intoxication?
hypocalcemia and hypomagnesemia
32
What is the first step in the treatment of a patient who has been rescued after drowning, is not breathing, and is without appreciable pulses?
Provide 2 rescue breaths before initiating chest compressions.
33
Which regional anesthetic technique is effective only for the first stage of labor?
Lumbar sympathetic block.
34
Which complication is most concerning for inadvertent removal of the parathyroid glands intraoperatively?
Tetany.
35
Which statement about nitrous oxide in labor analgesia is true for a pt who declines neuraxial analgesia?
Self-administered nitrous oxide can be used safely in labor analgesia.
36
A pt with pancreatic cancer undergoes an autonomic block for pain relief. This block would also alleviate visceral pain originating from which other organ?
adrenal glands and kidney
37
Which hormone is cleaved intravascularly during passage through the pulmonary circulation?
Angiotensin I.
38
Which medication would increase the seizure duration during electroconvulsive therapy?
Etomidate.
39
Which of the following is appropriate for preventing thermal burns during MRI?
Padding tubing and wires to reduce skin contact.
40
Which statement is true regarding anesthesia for ambulatory surgery?
Clonidine as an adjuvant may cause cardiovascular instability.
41
For pts with congenital prolonged QT syndrome who present with a sudden cardiac arrest, what is the most appropriate treatment?
Placement of implantable cardioverter-defibrillator
42
How can the risk of an acute exacerbation be decreased preoperatively in patients with acute intermittent porphyria?
Preoperative administration of IV fluids and glucose therapy can help decrease the risk of an acute exacerbation.
43
Which change in respiratory physiology would be found in patients with obesity compared to normal-weight patients?
Increased respiratory rate.
44
Which of the following is an effect of labor epidural analgesia?
It prolongs the second stage of labor.
45
Which volatile anesthetic used in ambulatory surgical centers has low blood gas solubility and minimal airway irritation?
Sevoflurane.
46
What is the mechanism by which a magnetic resonance imaging machine causes skin burns underneath a standard pulse oximeter probe?
Induction of electrical current within the probe.
47
Which laboratory result provides evidence of an acute kidney injury from hypovolemia?
Fractional excretion of sodium < 1%.
48
Blockade of which nerve would be most effective in disabling the glottic closure reflex and preventing laryngospasm?
Internal branch of the superior laryngeal nerve.
49
Which drug best treats the central neurologic symptoms of nerve gas poisoning?
Atropine.
50
According to the American Society of Anesthesiologists guidelines, which antacid is most appropriate to administer to a patient at high risk of aspiration for aspiration prophylaxis?
Sodium citrate.
51
What is autonomic dysreflexia (AD), and what are its most common causes?
Autonomic dysreflexia (AD), also known as autonomic hyperreflexia, is a complication of a spinal cord injury above the mid-thoracic (T5-7) level, typically triggered by a noxious stimulus below the level of the spinal cord lesion. The most common causes are bladder and bowel manipulation/pain.
52
How can antibiotic treatment of Gram-negative bacteria result in worsening hypotension?
Through the release of lipopolysaccharide, which provides more antigens for the septic response.
53
What are the risks and preferred timing for nonobstetric surgery during pregnancy?
Women undergoing nonobstetric surgery during pregnancy are at increased risk of aspiration, miscarriage, preterm labor, low birth weight, and Cesarean delivery. There is no established teratogenicity related to general anesthesia, but it is preferred to delay surgery until the second trimester to avoid fetal organogenesis during the first trimester, if possible.
54
Which pain treatment would be most beneficial for reducing the risk of postoperative ileus in pt with chronic kidney disease as part of the ERAS (enhanced recovery after surgery) colorectal surgery protocol?
Interfascial plane block.
55
What are somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP) used for, and where are their signals measured?
SSEPs and MEPs are used for detecting spinal cord ischemia in the posterior/lateral cord (SSEPs) or the anterior cord (MEPs). These potentials are measured at the point where their signals terminate, either in the brain (SSEPs) or in the peripheral nerves (MEPs).
56
What does the S4 heart sound signify?
Atrial contraction against a stiff, non-compliant ventricle.
57
What may patients who take ginseng preoperatively develop during surgery?
Intraoperative hypoglycemia.
58
Which respiratory effects do inhaled anesthetics have?
Decreases tidal volume, increases respiratory rate, with overall little effect on minute ventilation. Bronchodilates. Blunts ventilatory response to hypercarbia and hypoxia
59
Which medication should be avoided or limited in situations where pancreatitis is likely?
Propofol should be avoided or limited in situations where pancreatitis is likely because it can cause or worsen pancreatitis, potentially due to hypertriglyceridemia.
60
What causes Negative Pressure Pulmonary Edema (NPPE)?
Negative Pressure Pulmonary Edema (NPPE) is caused by a strong negative intrathoracic pressure that increases preload and left ventricular afterload with a decrease in cardiac output, leading to a transudation of fluid into the lungs.
61
Which drug would be expected to have a similar duration of action in a patient with renal failure compared to a healthy patient?
Propofol is hepatically metabolized into an inactive, renally excreted metabolite and, therefore, is minimally affected by renal function.
62
what is the alveolar gas equation and what is FiO2?
PAO2 =FiO2×(Patm−PH2O)−PaCO2/RQ
FiO2 = 0.21 regardless of altitude
63
What is a potential complication of general anesthesia in a patient in whom Duchenne’s muscular dystrophy has been diagnosed?
Patients in whom Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD) has been diagnosed are at an increased risk of aspiration due to respiratory muscle weakness, increased oral secretions, and gastric hypomotility. Respiratory complications are the major cause of morbidity in these patients.
64
Weakness in which muscle will result after the placement of an adductor canal block?
Vastus medialis
65
What can cause rebleeding during clipping of a cerebral aneurysm?
Factors that decrease a patient's intracranial pressure such as profound hyperventilation or rapid cerebrospinal fluid drainage can also worsen the transmural pressure across the wall of a cerebral aneurysm and thereby increase the risk for rebleeding.
66
What is the optimal tidal volume in acute respiratory distress syndrome (ARDS)?
6 mL/kg predicted body weight (PBW) or idea body weight (IBW).
67
Which medications should be avoided in a patient undergoing resection of a carcinoid tumor?
All medications which cause histamine release should be avoided – commonly used medications include morphine, meperidine, ketamine, and atracurium.
68
What are common complications of labor epidural placement?
post-dural puncture headache (PDPH) and hypotension
69
What are the classic risk factors that predict the need for postoperative mechanical ventilation in patients with myasthenia gravis undergoing transsternal thymectomy?
Disease duration > 6 years, chronic respiratory illness, pyridostigmine dosage > 750 mg/day (newer data suggest > 250 mg/day), and vital capacity < 2.9 L.
70
obesity is consistent with which type of lung disease?
restrictive lung disease, with proportional decreases in all lung volumes
71
What percentage of spinal cord blood supply comes from the anterior spinal artery?
The spinal cord receives its blood supply from 1 anterior spinal artery, which provides about 75% of the blood supply. The spinal cord also receives blood supply from 2 posterior spinal arteries, which together provide about 25% of the blood supply. The posterior spinal arteries primarily supply the sensory tracts in the spinal cord. The anterior spinal artery primarily supplies the motor tracts in the spinal cord.
72
What is the first-line therapy for reducing the risk of fatal cardiac events in congenital long QT syndrome?
For patients with congenital LQTS, beta blockers significantly reduce the risk of events like syncope and sudden cardiac death. It is thought that most cardiac events in these patients are related to high sympathetic output to the heart, which is blocked by beta blockers. Propranolol is the beta blocker of choice for the indication.
Conversely, beta blockers are often avoided in patients with acquired long QT syndrome because bradycardia can prolong the QT interval.
73
What is the best method of providing anesthesia in emergent cesarean deliveries?
general anesthesia with rapid sequence intubation
74
Chorionic villus sampling reveals a fetus to have one defective β globin allele. Upon delivery, how will the neonate likely present?
This infant with one defective β globin allele has beta-thalassemia minor. Infants with beta-thalassemia minor are asymptomatic at birth and without anemia or hepatosplenomegaly due to their reliance on fetal hemoglobin, which lacks β globins. If symptoms develop, they will begin to emerge around six months of age when production of the γ globin chain decreases.
75
For a pregnant patient with DIC, what is the most appropriate treatment plan?
Maintain fibrinogen >300 mg/dL and deliver the fetus as soon as possible.
76
What is negative pressure pulmonary edema and how does it present on a chest radiograph?
Negative pressure pulmonary edema, also known as post-obstructive pulmonary edema, occurs due to large negative intrathoracic forces generated by respiratory efforts against an obstructed upper airway. Findings include hypoxemia and bilateral fluffy infiltrates on the chest radiograph.
77
What is the most effective means of preventing postherpetic neuralgia (PHN) from a herpes zoster infection?
The most effective means of preventing PHN from a herpes zoster infection is prior vaccination with the varicella vaccine, which decreases the overall incidence of virus reactivation and reduces the severity of the disease and incidence of PHN if reactivation occurs.
78
What is anatomical dead space?
The portion of the tidal volume that does not participate in gas exchange because it remains in the conducting airways. Conditions that increase the volume of the conducting airways increase anatomical dead space.
79
What is physiological dead space?
The portion of the tidal volume that does not participate in gas exchange because it reaches poorly perfused alveoli (alveolar dead space). Conditions that compromise pulmonary perfusion increase alveolar dead space.
80
What conditions can increase alveolar dead space and how?
Alveolar dead space increases with decreased cardiac output (e.g., hemorrhage, hypovolemia, myocardial infarction), increased resistance to blood flow (e.g., ARDS, COPD), and obstructions to pulmonary blood flow (e.g., pulmonary embolism, air embolism, amniotic fluid embolism).
81
What are the absolute contraindications to TEE (transesophageal echocardiography) probe placement?
Absolute contraindications to TEE probe placement are perforated viscus, esophageal stricture, esophageal tumor, esophageal tear, esophageal diverticulum, and active upper GI bleed.
82
How does hepatic dysfunction affect the clearance and duration of action of midazolam?
Hepatic dysfunction reduces the clearance of midazolam due to decreased metabolism, leading to a prolonged duration of action. Therefore, benzodiazepines should be administered very carefully in patients with liver disease, and avoidance is often recommended.
83
which pediatric neurologic disorders would volatile anesthetics be most likely to produce an increased pharmacodynamic effect?
Patients with cerebral palsy (CP) are more sensitive to the effects of volatile anesthetics, and a lower minimum alveolar concentration (MAC) may be required to achieve surgical anesthesia.
84
What is true regarding prolonged muscle relaxation by succinylcholine?
Phase 1 and phase 2 blocks show decreased contraction with single twitch stimulus.
85
What is the most important initial step in the management of an incompetent inspiratory valve?
The most important initial step is to increase fresh gas flow to minimize or eliminate rebreathing. The faulty inspiratory unidirectional valve should then be replaced as soon as possible. Increasing fresh gas flow will help decrease the amount of exhaled gas that flows retrograde into the inspiratory system and thus will decrease the extent of rebreathing.
86
what type of lung disease does obesity cause and which measure is normal or elevated?
Spirometry values such as forced expiratory volume in 1 sec (FEV₁) and forced vital capacity (FVC) are slightly decreased with increasing body mass index, and the ratio of FEV₁/FVC remains relatively preserved or slightly increased as both values are decreased similarly. The pulmonary function test results of obesity are best characterized by the pattern of restrictive pulmonary disease. This is due to the increased mass of adipose tissue on the chest wall and abdomen, which restricts lung expansion and reduces lung volumes.
87
A patient in the PACU after endoscopic retrograde cholangiopancreatography (ERCP) is complaining of worsening right upper quadrant pain. Which of the following is most appropriate?
Naloxone. Opioids can induce biliary colic, particularly in susceptible patients. This can be alleviated by blocking opioid receptor activation or by blocking parasympathetic activation. Activation of biliary smooth muscle is prevented by efferent innervation. This innervation is inhibited by opioid receptor activation. In patients with biliary disease, the frequent contractions induced can result in biliary colic. The pressure in the common bile duct can increase ten times baseline during these contractions. With morphine, increased biliary activity can last for more than two hours.
88
Where is most triiodothyronine (T3) formed?
The thyroid secretes T₃ and T₄, which are the regulators of metabolism and homeostasis. Most T₃, the more potent hormone of the two, is formed through peripheral conversion of T₄.
T₃ is more potent than T₄ due to its higher serum concentration on account of its decreased protein binding. Most circulating T₃ is formed peripherally by the conversion of T₄ by partial deiodination via the enzyme 5'-deiodinase.
89
Patients with which congenital neuromuscular disorder are the most resistant to non-depolarizing neuromuscular blocking drugs (NNMBDs)?
Myotonia congenita.
Myotonia congenita is caused by mutations in the chloride channel. This channel is essential for stabilizing the resting membrane potential of muscle cells. In myotonia congenita, the defective chloride channels result in increased membrane excitability, leading to sustained muscle contraction.
The increased excitability of muscle membranes in myotonia congenita means that even if NNMBDs block the acetylcholine receptors, the muscle cells can still be more easily depolarized due to the altered ion channel behavior. This makes it harder for NNMBDs to achieve the desired muscle relaxation.
90
What should be avoided during fluid resuscitation of major burn injuries in adults?
Administration of glucose-containing crystalloids is not recommended in adult burn patients. Since large volumes of crystalloid are usually administered to burn patients, added glucose could cause hyperglycemia, especially since burns tend to increase insulin resistance.
The combination of inflammatory cytokines, stress hormones, hypermetabolism, and impaired insulin signaling contributes to the development of insulin resistance in individuals with severe burns.
Immediately following a major burn, systemic and pulmonary microvasculature becomes highly permeable causing loss of protein-rich fluid into the interstitial space. Adequate fluid resuscitation can limit microvascular permeability and edema formation.
91
Where is the local anesthetic deposited in a transversus abdominis plane (TAP) block, and what are the three muscle layers of the abdominal wall from superficial to deep?
The local anesthetic is deposited between the internal oblique (IO) and transversus abdominis (TA) muscles. The three muscle layers of the abdominal wall from superficial to deep are the external oblique (EO), internal oblique (IO), and transversus abdominis (TA).
92
What nerves are anesthetized by a transversus abdominis plane (TAP) block, and where do they traverse?
The TAP block anesthetizes the anterior rami of the thoracolumbar spinal segmental nerves from T7-L1 as they traverse between the internal oblique (IO) and transversus abdominis (TA) muscles.
93
What should plateau pressures be kept below to prevent acute lung injury?
Plateau pressures should be kept below 30 cmH2O to prevent acute lung injury.
94
What is the recommended initial management of a sharps injury, and does squeezing the wound help reduce the risk of bloodborne pathogen transmission?
The wound should be washed with soap and water. Squeezing the wound to express fluid has not been shown to decrease the risk of bloodborne pathogen transmission.
95
What initially helps compensate for acute respiratory acidosis?
Plasma protein buffers, including hemoglobin in red blood cells and other plasma proteins, initially help compensate for acute respiratory acidosis.
96
What is characteristic of pyloric stenosis?
Increased urine specific gravity.
Pyloric stenosis commonly presents as a hypochloremic, hypokalemic, metabolic alkalosis with compensatory respiratory acidosis. Elevated serum bicarbonate is often present along with increased urine specific gravity and decreased urine chloride.
Elevated urine specific gravity is consistent with dehydration, and urine chloride is decreased as the kidneys conserve all available chloride. Urine chloride usually approaches zero in pyloric stenosis.
Patients with pyloric stenosis may present with hypovolemia secondary to vomiting and decreased oral intake. These patients commonly present with a hypokalemic, hypochloremic metabolic alkalosis. This is often accompanied by compensatory respiratory acidosis. Chloride and hydrogen ion-rich gastric fluids are lost in pyloric stenosis.
97
What has NOT been associated with side effects or an exacerbation of symptoms in patients with multiple sclerosis?
Epidural anesthesia.
Patients with MS are susceptible to an exacerbation of their symptoms in the perioperative period caused by surgery and the use of general or spinal anesthesia. Succinylcholine should be used cautiously or avoided.
98
What is a beneficial physiological effect of colloid solutions?
Reduction in plasma viscosity.
The beneficial physiological effects of colloids result from their long intravascular half-lives (three to six hours) and ability to increase capillary oncotic pressure, which minimizes transcapillary filtration, accounting for their ability to expand intravascular volume.
In addition, colloid solutions alter blood flow dynamics and can improve blood flow through hemodilution, reduction in plasma viscosity, and reduced red cell aggregation effects.
99
What are the contraindications to enteral nutrition?
intractable vomiting and diarrhea, bowel obstruction, gastrointestinal ischemia or bleeding, hemodynamic instability, severe and protracted ileus, or high-output fistulas.
100
At what gestational age is the use of fetal heart rate monitoring (FHR) feasible?
Fetal heart rate monitoring (FHR) is feasible beginning at 18-20 weeks gestation.
Prior to 18-20 weeks, the fetus is too small and mobile to reliably monitor FHR.
101
What are the ASA 2013 fire prevention recommendations for airway laser surgery?
During airway laser surgery, the polyvinyl endotracheal tube has been a source of fuel for fire. The ASA 2013 fire prevention recommendations include using a laser-resistant tube to reduce this risk. It is also recommended to fill the cuff of a cuffed tube with saline and use methylene blue dye in the cuff to rapidly identify cuff leaks caused by lasers. Cuff tear will lead to a leak around the tube and expose the surgical field to high oxygen concentrations from the trachea.
FiO2 (delivered to the patient) should be kept as low as clinically feasible when an ignition source is in proximity to an oxygen-enriched atmosphere. The reduction of FiO2 should be guided by monitoring patient oxygenation (e.g. pulse oximetry).
102
What is most likely to occur in the smooth muscle cells of the pulmonary vasculature following initiation of inhaled nitric oxide (NO)?
Increased cyclic guanosine monophosphate (cGMP).
103
What is the approximate rate of brain glucose metabolism in the brain?
Approximately 5 mg/100 g/min.
104
What describes the meaning of the ED95 dose in reference to neuromuscular blockers?
ED95 is the effective dose of a neuromuscular blocking drug required to achieve 95% block of a single twitch in 50% of individuals who receive this drug and dose. For effective relaxation during intubation, one to two times the ED95 is typically administered.
In general pharmacology, ED95 refers to the effective dose needed to get the desired effect for 95% of the population. Unfortunately, this term has a different meaning specifically for neuromuscular blocking agents. For these agents, ED95 refers to the median dose required to achieve a 95% reduction in the maximal twitch response from baseline, in 50% of the population.
105
When infusion of an oxytocin solution fails to help achieve uterine atony along with uterine massage, which second-line uterotonic agents should be considered?
methylergonovine
This drug is contraindicated in patients with coronary artery disease and preeclampsia/eclampsia as it can cause coronary artery spasm and systemic vasoconstriction that increases systemic hypertension. This could lead to stroke in a preeclamptic patient.
Carboprost
Carboprost is a synthetic form of prostaglandin F-2-alpha.
Patient with a history of asthma would contraindicate administration of a prostaglandin-derived medication, because it increases pulmonary vascular resistance that can cause pulmonary hypertension and induces bronchoconstriction.
106
What are the complications associated with perioperative hyperglycemia?
Perioperative hyperglycemia is associated with immunosuppression, increased infections, osmotic diuresis, delayed wound healing, delayed gastric emptying, sympatho-adrenergic stimulation, increased mortality, reduced skin graft success, exacerbated brain, spinal cord, and renal damage by ischemia, worsened neurologic outcomes in traumatic head injuries, and postoperative cognitive dysfunction following CABG.
107
When does physiologic anemia of infancy occur in full-term infants, and how does it compare to anemia in preterm infants?
Physiologic anemia of infancy occurs around 2-3 months of age in full-term infants, with hemoglobin levels reaching a nadir of 10 gm/dL. In preterm infants, the drop in hemoglobin is more severe and occurs earlier compared to term infants, known as anemia of prematurity.
108
How does ketamine affect respiratory function, and in what conditions is it particularly effective?
Ketamine is a respiratory stimulant that promotes central respiratory drive, maintains spontaneous ventilation, and provides bronchial smooth muscle relaxation. It is effective in patients with severe asthma and status asthmaticus that is refractory to standard therapy.
109
What are the roles and characteristics of type I and type II pneumocytes in the lungs?
Gas exchange occurs across single layer type I pneumocytes, which are squamous epithelial cells. Surfactant is produced by type II pneumocytes, which are cuboidal.
110
How is abdominal compartment syndrome defined and diagnosed?
Abdominal compartment syndrome is defined as an intraabdominal pressure of greater than 20 mmHg with evidence of organ dysfunction, typically renal injury. Diagnosis is made by indirect measurement of intra-abdominal pressures using the pressures of intra-abdominal hollow viscus structures (bladder, stomach, colon) or vascular structures (inferior vena cava), with intravesicular (bladder) pressure being the most commonly used.
111
What mediates the resting tone of airway smooth muscle and what effects does it have?
The resting tone of airway smooth muscle is primarily mediated by the parasympathetic nervous system, supplied by branches of cranial nerve X (vagus nerve). This causes bronchoconstriction, tracheobronchial secretion, and wheezing.
112
What are Chassaignac tubercles and what is their significance?
Chassaignac tubercles are paired anterior tubercles located on the transverse process of the sixth cervical vertebra. They serve as landmarks for common blocks such as stellate ganglion, brachial plexus, and cervical plexus blocks. They are also known as the carotid tubercle because of the risk of compression of the carotid artery.
113
What is the mechanism of beta-agonist induced bronchodilation?
The mechanism of beta-agonist induced bronchodilation involves activation of the beta-2-adrenergic receptor, which leads to Gs protein effects, cAMP generation, decreased intracellular calcium, and resulting airway smooth muscle relaxation.
114
What is the role of cytochrome p450 in drug metabolism?
Cytochrome p450 is involved in phase I metabolism by oxidizing many drugs. It is a heme protein that utilizes molecular oxygen to oxidize organic compounds and consists of a group of closely related proteins embedded in the endoplasmic reticulum.
115
How do the anatomical features of the airway in pediatric patients compare to those in adults?
Pediatric patients have an elliptical subglottis, larger tongues and occiputs, a cephalically-displaced larynx, anteriorly-displaced vocal cords, and a floppy omega-shaped epiglottis.
116
What are the goals of hemodynamic management in patients with severe mitral regurgitation (MR)?
The goals include maintaining a normal to high heart rate, relatively low afterload (SVR), avoidance of increases in preload, and avoiding conditions that cause pulmonary vasoconstriction.
117
What precautions should be taken when administering general anesthesia to a patient with an anterior mediastinal mass?
Spontaneous ventilation should be maintained. If paralysis is required, confirmation of the ability to ventilate and oxygenate must occur first, and only small doses of a short-acting muscle relaxant should be used.
118
What is the most common cause of death from subarachnoid hemorrhage (SAH) and when does it typically peak?
The most common cause of death from subarachnoid hemorrhage (SAH) is initial bleeding, followed by rebleeding. Rebleeding peaks within 24 hours following initial hemorrhage. Neurologic deficits from vasospasm rarely occur within the first 3 days, typically peak in 5-10 days, and resolve over 10-14 days.
119
What are the indications for hyperbaric oxygen therapy?
Indications for hyperbaric oxygen therapy include air embolism, decompression sickness, carbon monoxide and cyanide poisoning, certain types of infections, ischemia, hypoxia, burn injuries, and idiopathic sudden sensorineural hearing loss.
Hyperbaric oxygen (HBO) was trialed during surgical correction of cyanotic congenital heart disease but was not found to be of benefit.
120
What does the positive predictive value (PPV) of a diagnostic test represent and how is it calculated?
The positive predictive value (PPV) represents the probability that a patient with a positive result actually has the disease. It can be calculated using the equation:
PPV = True Positive/(True Positive+False Positive)
121
What are delayed hemolytic transfusion reactions, when do they occur, and what are their typical symptoms?
Delayed hemolytic transfusion reactions occur at least 24 hours, most often one to two weeks (but as many as four weeks), after the initial transfusion. These reactions are most likely an anamnestic response (a rapid production of antibodies after re-exposure to the initial antigen) to red blood cell antigens. The initial exposure can be from pregnancy, solid or hematopoietic cell transplant, or previous transfusion. Symptoms are often mild and include a low-grade fever and jaundice.
122
What are the risk factors most associated with the development of postoperative cognitive dysfunction?
The risk factors most associated with the development of postoperative cognitive dysfunction include advanced age, prior neurologic insults, and lower educational attainment.
123
What are the characteristics and differentiating features of Anterior Ischemic Optic Neuropathy (AION) compared to Posterior Ischemic Optic Neuropathy (PION)?
Anterior Ischemic Optic Neuropathy (AION) is believed to occur due to temporary loss of or hypoperfusion to the vessels supplying the anterior part of the optic nerve. Patients typically present with sudden, unilateral, painless loss of vision, altitudinal field defects, optic disc edema or pallor, and afferent pupillary defects. AION can be differentiated from Posterior Ischemic Optic Neuropathy (PION) because AION involves optic disc edema or pallor, while PION has no significant findings on examination.
124
What is the role of precapillary sphincters in controlling blood flow, and how is their function influenced by oxygen concentration?
Precapillary sphincters are smooth muscle fibers that encircle the transition point between metarterioles and capillaries. They can open or close to control blood flow into the capillaries. The concentration of oxygen plays a major role in the function of these smooth muscle fibers, either through direct effects or by influencing the production of vasodilating substances as products of metabolic processes reliant on oxygen.
125
What are the characteristics and diagnostic considerations for sepsis-associated encephalopathy (SAE)?
Sepsis can cause sepsis-associated encephalopathy (SAE) with symptoms ranging from delirium to coma, even in the absence of CNS infection. Disruption of the blood-brain barrier and inflammation in the brain can lead to SAE. Abnormalities in MRI and EEG can be seen, but SAE is a diagnosis of exclusion and CNS infections must be ruled out.
Vasogenic edema is a type of cerebral edema that occurs when the blood-brain barrier (BBB) is disrupted, leading to the leakage of fluid and plasma proteins from the vascular space into the extracellular space of the brain.
126
How long do the symptoms of neonatal myasthenia gravis persist, and what happens to these symptoms over time?
The symptoms of neonatal myasthenia gravis persist for up to four weeks and diminish as the maternal antibodies against postsynaptic acetylcholine receptors are cleared. By two months, nearly 90% of affected infants will have complete resolution of symptoms.
127
Which condition has the highest risk of hemorrhage requiring massive transfusion during delivery, and what is the typical blood loss associated with it?
Placenta accreta has the highest risk of hemorrhage requiring massive transfusion, with the more invasive types (e.g., percreta) having the most risk. Most accreta cases have greater than 2000 mL blood loss during delivery.
128
What are the indications for the administration of fresh frozen plasma (FFP) according to the American Society of Anesthesiologists (ASA), and for what purpose is FFP not indicated?
According to the ASA, FFP is not indicated for the sole purpose of plasma volume expansion. The indications for administering FFP include:
- Correction of excessive microvascular bleeding (PT > 1.5 times normal, PTT > 2 times normal, or INR > 2).
- Correction of coagulation factor deficiencies if the patient has been transfused with more than one blood volume (approximately 70 ml/kg).
- Urgent reversal of warfarin therapy (prothrombin complex concentrate is another option).
- Correction of coagulation factor deficiencies for which there are no specific replacements.
- Heparin resistance (antithrombin III deficiency) in a patient requiring heparin.
Thrombotic thrombocytopenic purpura (TTP) is treated with FFP to replete the ADAMTS13 enzyme in both inherited and acquired forms. Plasmapheresis may be used to treat the acquired type by removing antibodies that damage the ADAMTS13 enzyme.
129
Why do infants and small children require larger weight-based dosing of muscle relaxants, and why is succinylcholine not routinely recommended for use in children?
Infants and small children have larger extracellular fluid volumes by percentage of total body water (TBW) and therefore require larger weight-based dosing of muscle relaxants. This is because they have a relatively large volume of distribution, necessitating increased weight-based dosing of most medications for the initial effect.
Succinylcholine is not routinely recommended for use in children due to the possibility of hyperkalemia from undiagnosed muscular dystrophy. It is reserved for situations where rapid sequence induction/intubation is required.
130
What are the effects of increased minute ventilation during pregnancy, and how are they represented on arterial blood gas analysis?
Increased minute ventilation occurs as early as the first trimester of pregnancy and leads to respiratory alkalosis with compensatory metabolic acidosis. On arterial blood gas analysis, this effect is represented by a normal to slightly increased pH, decreased PaCO₂, decreased serum bicarbonate level, and decreased base excess. Increased alveolar ventilation also leads to an increase in PaO₂.
131
What is the mechanism of action of nitrous oxide, and through which receptor is its primary anesthetic effect mediated?
Nitrous oxide is a mixed competitive/noncompetitive antagonist at the N-methyl-D-aspartate (NMDA) receptor. Although it interacts at multiple receptor types, including glycine, nicotinic acetylcholine, and serotonin receptors, it is primarily through NMDA antagonism that most of its anesthetic effects are mediated.
132
In cases of refractory ventricular fibrillation or pulseless ventricular tachycardia that persists after one or more shocks, which medication should be considered next after epinephrine, and what role does vasopressin play in this scenario?
In cases of refractory ventricular fibrillation, defined as ventricular fibrillation or pulseless ventricular tachycardia that persists after one or more shocks, amiodarone should be considered. Epinephrine is often initiated and should be given early in CPR.
In patients with refractory ventricular fibrillation despite a prolonged CPR course and rounds of epinephrine and defibrillation, amiodarone should be considered next.
Vasopressin offers no more benefit than epinephrine and has been removed from the algorithm for simplification. Procainamide is appropriate for supraventricular tachycardia, atrial flutter, and ventricular tachycardia with a pulse.
133
Where and how should an axillary roll be placed, and why should it never be placed in the axilla?
An axillary roll should be placed just caudad to the axilla beneath the dependent rib cage. It should be oriented anterior-posteriorly to support the rib cage anterolaterally and extend to the area beneath the scapula posterolaterally. An axillary roll should never be placed in the axilla to avoid compressing neurovascular structures.
134
What is the concern with administering succinylcholine to patients with myotonic dystrophy?
Succinylcholine can cause excessive fasciculations/contractures in myotonic dystrophy patients, impairing their ability to ventilate and intubate.
135
What are some additives to peripheral nerve blocks that prolong analgesia when combined with local anesthetics?
Additives to peripheral nerve blocks include epinephrine, steroids such as dexamethasone, and alpha-2-adrenergic agonists such as clonidine. These agents have been shown to prolong analgesia when combined with local anesthetics. Epinephrine does not significantly prolong ropivacaine and bupivacaine epidural and peripheral nerve blockade. Bicarbonate may lead to precipitation of local anesthetics.
136
What serves as the major efferent pathway for the hippocampus?
The fornix is composed of the axons of pyramidal neurons within the hippocampal formation, and it serves as the major efferent pathway for the hippocampus.
The hippocampus receives sensory input from the body and transmits it to various regions of the brain. It plays a major role in memory formation and is an integral component of the pathway between sensory input and behavioral responses. The hippocampus projects its main efferent fibers via axons of pyramidal neurons that together form the fornix.
137
What happens during anaerobic glycolysis in oxygen-deprived cells or cells without mitochondria?
Anaerobic glycolysis generates 2 ATP by converting pyruvate into lactate via lactate dehydrogenase, producing 1 molecule of NAD⁺ for continued ATP production in glycolysis.
138
What does power in a statistical test determine?
Power determines the chance of correctly rejecting the null hypothesis (H₀) when the alternative hypothesis (Hₐ) is true, calculated as 1-β, where β is the probability of a Type II error (false negative).
139
What effect do calcium channel blockers have on neuromuscular blockers when taken chronically?
Calcium channel blockers can have a minor potentiation effect on both depolarizing and nondepolarizing neuromuscular blockers, but this effect is clinically insignificant.
140
What is the vertebra prominens and why is it significant?
The vertebra prominens (C7) is the most superior spinous process visible when the neck is flexed. C7 is the most superior process that is visible, but the spinous process of T1 may be the most prominent in some people.
The first rib arises from the first thoracic vertebrae.
141
What changes occur during the storage of PRBCs?
Storage of PRBCs is associated with a gradual decrease in pH and 2,3-DPG, and an increase in potassium.
Red blood cells rely on glycolysis for energy production, and 2,3-DPG is a byproduct of glycolysis. Over time, the metabolic activity of stored red blood cells decreases, leading to reduced production of 2,3-DPG.
142
Does aprepitant require dosing adjustments for the geriatric population?
No, aprepitant does not require dosing adjustments in the geriatric population, and studies have shown no increase in side effects with standard dosing, even in the elderly.
143
Which nerve is unaffected by the lithotomy posiiton?
The posterior cutaneous nerve of the thigh is largely unaffected by the lithotomy position. It arises from S1-3 and supplies sensation to the skin of the posterior thigh, leg, and portions of the perineum.
144
What are some well-supported benefits of leukoreduction during the processing of red blood cells?
Leukoreduction during the processing of red blood cells decreases the risk of transmission of cytomegalovirus, Epstein-Barr virus, and human T-lymphotropic virus diseases.
145
What can be a site for inadvertent arterial injection when performing an interscalene nerve block?
The vertebral arteries most commonly originate from the subclavian arteries and are divided into four segments depending on their anatomic location. They traverse the neck anterior to the scalene muscle and enter the vertebral foramina of the sixth cervical vertebra. It can be a site for inadvertent arterial injection when performing an interscalene nerve block.
146
What causes acute hemodynamic changes during carotid endarterectomy (CEA)?
Acute hemodynamic changes during carotid endarterectomy can occur due to compression of the carotid sinus, leading to increased baroreceptor output, decreased sympathetic discharge, and increased parasympathetic discharge.
147
What are the effects of hypercarbia and how does it progress?
Hypercarbia initially causes a respiratory response according to the CO₂ response curve, but progression results in profound acidosis, hypotension, and cardiac arrhythmias. Sympathetic stimulation may normalize blood pressure or cause hypertension with profound hypercarbia, and hypercarbic narcosis tends to present at a partial pressure of 100-120 mmHg.
148
How does ketamine affect sympathetic stimulation and hemodynamic parameters?
Ketamine may result in sympathetic stimulation with elevated blood pressure and heart rate. However, in patients with depleted catecholamine levels from critical illness, this effect may not occur, potentially causing a fall in hemodynamic parameters like blood pressure.
Ketamine is known as a more “stable” induction agent because it often maintains hemodynamic parameters. Ketamine is one of the only induction medications that stimulate the sympathetic nervous system. It can lead to an increase in blood pressure and heart rate.
149
What artery supplies the AV node, bundle of His, and the proximal part of the bundle branches, and what are the common variations in its blood supply?
The atrioventricular (AV) nodal artery supplies the AV node, bundle of His, and the proximal part of the bundle branches. It is most commonly supplied by a branch of the right coronary artery, with rarer variations including the left circumflex or a combination of the left circumflex and right coronary arteries.
150
Why do colorectal ERAS guidelines recommend consuming a clear, complex carbohydrate beverage up to two hours before surgery?
Consuming a clear, complex carbohydrate beverage up to two hours before surgery is recommended because it has improved outcomes compared to fasting for more than eight hours, decreases insulin resistance, and results in better glycemic control in patients undergoing colorectal surgery.
151
US, gas-color
oxygen?
green
think green oxygen tanks
152
US, gas-color
carbon dioxide
gray
think gray smoke from burning
153
US, gas-color
nitrous oxide
blue
think blue belt before black belt in tae kwon do
154
US, gas-color
nitrogen
black
think N2 -> double black belt in tae kwon do
155
US, gas-color
air
yellow
think yellow sunlight permeating the environment/all the air around us
156
US, gas-color
helium
brown
think helium filled balloon rising from the ground with brown soil
157
What is the most common risk associated with autologous blood transfusion, and why are hemolytic and non-hemolytic transfusion reactions uncommon?
The most common risk associated with autologous blood transfusion is infection from improper storage. Hemolytic and non-hemolytic transfusion reactions are uncommon because autologous blood does not contain non-self antigens.
158
What nerves are targeted in an axillary block, and how is additional coverage achieved for the lateral forearm and medial upper arm?
An axillary block targets the median, radial, and ulnar nerves at the level of the branches. Additional coverage for the lateral forearm is achieved by supplementing the musculocutaneous nerve, and for the medial upper arm by supplementing the intercostobrachial nerve.
159
What electrolyte abnormalities can promote digoxin toxicity, and which medication can cause these abnormalities?
Hypercalcemia, hypokalemia, and hypomagnesemia can promote digoxin toxicity. Hydrochlorothiazide, a thiazide diuretic that causes hypercalcemia, hypomagnesemia, and hypokalemia, can lead to these electrolyte abnormalities.
160
What is the Parkland formula for fluid resuscitation in burn patients, and how should the fluid be administered?
The Parkland formula is 4 mL × total body weight (kg) × percentage of burned total body surface area. The first half of the total crystalloid fluid should be administered within the first 8 hours, and the second half should be given over the following 16 hours after the burn insult.
161
What effects can the administration of mannitol have on plasma volume and pulmonary capillary wedge pressure?
Mannitol administration can increase plasma volume, resulting in higher blood pressure and cardiac output, potentially leading to increased pulmonary capillary wedge pressure, especially in patients with heart failure.
162
Where do the cervical nerves emerge relative to their corresponding vertebrae?
All cervical nerves except C8 emerge above their corresponding vertebrae, while the C8 nerve emerges below the C7 vertebra.
163
Why do patients with multiple sclerosis require careful anesthetic medication planning, particularly regarding neuromuscular blocking agents?
Patients with multiple sclerosis require careful anesthetic medication planning because their response to neuromuscular blocking agents varies based on symptomatology and disease severity. They may be sensitive to succinylcholine, which could result in a severe hyperkalemic response if administered.
164
What is the order of opioids from least to most lipophilic based on the octanol/H₂O partition coefficient when used for neuraxial anesthesia?
When opioids are used for neuraxial anesthesia, hydrophilic opioids spread more extensively and persist longer within the cerebrospinal fluid or epidural space. The order of the least to the most lipophilic opioids based on the octanol/H₂O partition coefficient is hydromorphone (1.3) > morphine (1.4) > alfentanil (145) > fentanyl (813) > and sufentanil (1778).
The spread of opioids within the cerebrospinal fluid is more extensive with the less lipid-soluble (ie, hydrophilic) opioids, such as morphine, compared to the more lipid-soluble opioids. The spread is more extensive with the hydrophilic opioids due to the slower uptake into blood vessels and elimination from the cerebrospinal fluid and epidural space. Because hydrophilic opioids spread more extensively and persist longer within the cerebrospinal fluid or epidural space, they have a higher risk of respiratory depression after intrathecal injection hours after use.
165
What are the onset and duration of action times for succinylcholine and rocuronium?
Succinylcholine:
- Onset of Action: Typically within 30 to 60 seconds.
- Duration of Action: Approximately 5 to 10 minutes.
Rocuronium:
- Onset of Action: Approximately 1 to 2 minutes at standard intubating doses (0.6 mg/kg). The onset can be as fast as 60 seconds when higher doses are used (1.0-1.2 mg/kg).
- Duration of Action: Approximately 30 to 60 minutes at standard intubating doses.
166
What is the effect of St. John's wort on cytochrome P450 enzymes and specific medications?
St. John's wort is a known CYP3A4 and CYP2C9 inducer, which can decrease serum levels of medications metabolized by these enzymes, such as cyclosporine and warfarin. This can result in transplant rejection if cyclosporine levels become subtherapeutic and decreased efficacy of warfarin.
167
How can hepatic synthetic function be assessed and which product decreases first?
Hepatic synthetic function can be assessed by measuring synthetic products such as factor VII (or PT), fibrinogen, and albumin. The first product to decrease is factor VII, which has a half-life of four hours and can be measured by assessing PT. Albumin takes longer to decrease as its half-life is 20 days.
168
When should perioperative steroid supplementation with hydrocortisone be administered to patients on chronic corticosteroids?
Perioperative steroid supplementation with hydrocortisone should be administered to patients taking ≥20 mg/day of prednisone (or equivalent) for at least three weeks in the previous year and may be considered in patients taking 10-20 mg/day.
169
What is the overall goal of perioperative fluid management in colorectal surgery, and what type of fluid is recommended?
The overall goal is to maintain end-organ perfusion without causing cardiopulmonary complications. For colorectal surgery, buffered isotonic crystalloids such as lactated Ringer's solution are recommended.
170
What are the effects of dexmedetomidine on evoked potential monitoring, sedation, neuroprotection, and central analgesia?
Dexmedetomidine has minimal to no direct impact on evoked potential monitoring. Its sedation mimics non-rapid eye movement sleep. It may be neuroprotective by decreasing the release of proapoptotic peptides and excitatory neurotransmitter glutamate during cerebral ischemia. Central analgesia is provided by decreasing the release of pronociceptive substances such as substance P and glutamate and through hyperpolarization of nociceptive interneurons.
171
What are the effects of morphine on preload, afterload, myocardial oxygen demand, coronary perfusion pressures, and respiratory depression?
Morphine reduces preload and afterload, which reduces myocardial oxygen demand and improves coronary perfusion pressures by reducing ventricular EDV and EDP. It has minimal effect on myocardial contractility by itself but may cause myocardial depression when combined with volatile anesthetics. All μ-opioid agonists cause dose-dependent respiratory depression by decreasing the sensitivity of central chemoreceptors to elevated levels of CO₂.
172
What are the potential electrolyte and metabolic side effects of hydrochlorothiazide?
Hydrochlorothiazide can cause hypokalemia, hypomagnesemia, hyponatremia, hypercalcemia, hyperuricemia, hyperglycemia, hypercholesterolemia, increased LDL production, and hypertriglyceridemia.
173
How do anesthesia and glucagon affect hepatic blood flow, and what role does the hepatic arterial buffer response play?
Anesthesia decreases hepatic blood flow, while glucagon increases it. The hepatic arterial buffer response partially compensates for decreases in portal blood flow by increasing hepatic arterial blood flow.
174
What rare complication can cause postoperative hoarseness immediately after endotracheal intubation?
Arytenoid subluxation can cause postoperative hoarseness immediately after endotracheal intubation.
175
How does acetazolamide cause metabolic acidosis, and what is the typical respiratory compensation?
Acetazolamide, a carbonic anhydrase inhibitor, prevents the reabsorption of serum bicarbonate (HCO₃⁻) in the proximal tubule, leading to increased loss of HCO₃⁻ and resulting in metabolic acidosis. This is often accompanied by a decrease in partial pressure of carbon dioxide as respiratory compensation.
176
What are the cardiovascular effects of methohexital, and what mechanisms lead to cardiovascular depression from barbiturates?
Methohexital can decrease cardiac output, decrease systemic vascular resistance, and cause reflex tachycardia, which could be harmful in patients with coronary artery disease. Cardiovascular depression from barbiturates results from central and peripheral effects, including:
- Direct negative inotropic action due to decreased calcium influx into cells
- Decreased ventricular filling caused by increased capacitance
- Transiently decreased sympathetic outflow from the central nervous system
- The primary effect during anesthesia induction is peripheral vasodilation, causing blood pooling in the venous system.
177
Why might an additional intercostobrachial nerve block be necessary during a brachial plexus block, and how is it performed?
The intercostobrachial nerve is spared during a brachial plexus block and innervates the medial aspect of the arm. If this area requires anesthesia to prevent tourniquet or surgical pain, an additional intercostobrachial nerve block is necessary. This block is performed by a subcutaneous field block injection starting at the deltoid prominence and proceeding inferiorly in a linear fashion along the medial upper arm.
178
What measurements are reliable indicators of fluid responsiveness, and what is the typical stroke volume variations cutoff?
Dynamic measurements such as arterial pressure variation, which includes stroke volume variations and pulse pressure variations, are reliable indicators of fluid responsiveness. The typical stroke volume variations (SVV) cutoff used is 13%, with SVV > 13% suggesting fluid responsiveness.
179
Which nerve is blocked by transtracheal injection of local anesthetic through the cricothyroid membrane?
Transtracheal injection of local anesthetic through the cricothyroid membrane will block the recurrent laryngeal nerve, anesthetizing the vocal cords and trachea during awake intubation.
180
What are the considerations and relative contraindications for monitored anesthesia care (MAC)?
When selecting patients for monitored anesthesia care (MAC), factors such as surgical procedure details, patient comorbidities, history, physical examination, and operative room logistics must be considered. There are no absolute contraindications to MAC, but relative contraindications include the inability to lie still enough for the procedure, the inability to cooperate, and the inability to communicate with the care team.
181
What does the modified Aldrete scoring system assess, and which vital sign is not included in this scoring system?
The modified Aldrete scoring system assesses readiness for discharge from Phase I of PACU by looking at motor activity of extremities, respiratory quality, blood pressure, consciousness, and oxygen saturation value. Heart rate is not included in either the original or the modified Aldrete scoring system.
182
What factors increase the risk of intraoperative awareness?
difficult intubation
obesity
chronic alcohol, benzodiazepine, and opioid use
183
What are the key management steps for aspiration, and what treatments are not recommended?
Management of aspiration includes placing the patient in a head-down or lateral position and initiating supplemental oxygen. Not all patients necessarily require intubation or positive pressure ventilation. Bronchoscopy is recommended prior to positive pressure ventilation for large particles to avoid pushing the aspirates further into the lungs. Prophylactic antibiotic treatment and steroids are not recommended.
184
What is Aprepitant and what are its advantages over other anti-nausea medications?
Aprepitant is a neurokinin type 1 (NK1) receptor antagonist effective for preventing vomiting for up to 48 hours postoperatively. It does not cause any changes in ECG, unlike other anti-nausea medications such as droperidol, haloperidol, and ondansetron, which can cause QT prolongation.
185
What is the most sensitive lead for detecting myocardial ischemia during procedures?
When used alone, V5 is the most sensitive lead for myocardial ischemia. However, single-lead monitoring is typically performed to detect rhythm changes during procedures and not ischemia alone. The preferred combination monitoring setup is Lead II + V5, as it monitors both rhythm changes (Lead II) and ischemia (V5).
186
What are the initial treatments for laryngospasm, and why should succinylcholine be used with caution in pediatric patients?
The initial treatment of laryngospasm includes administration of 100% oxygen, CPAP, removal of any offending foreign bodies or secretions, and increasing the depth of anesthesia. Succinylcholine may be used as a last resort and with caution in pediatric patients due to bradycardia and the risk of triggering malignant hyperthermia or rhabdomyolysis.
187
What is a potential postoperative consequence of metabolic alkalosis in infants with pyloric stenosis?
A potential postoperative consequence of metabolic alkalosis in infants with pyloric stenosis is apnea. Patients with pyloric stenosis develop metabolic alkalosis that results in CNS alkalosis, leading to alterations in breathing patterns after exposure to general anesthesia.
188
how does local anesthetic accumulation occur in the fetus?
fetal acidosis converts nonionized form of local anesthetic to ionized form because they are basic drugs. ionized drugs cannot easily cross the placental membrane i.e. "ion trapping"
189
what is pharmacodynamics?
the study of the effects of drugs on the body and the mechanism of their action. i.e. what the drug does to the body
190
what is pharmacokinetics?
the study of how the body absorbs, distributes, metabolizes, and excretes a drug. i.e. the movement of drugs within the body over time
191
how does thiopental's action terminate?
redistribution because it's highly lipophilic
192
which abx has activity against both MRSA and gram-negative bacteria?
tigecycline, ceftaroline, TMP-SMX
193
what are the FDA black box warnings for carbamazepine?
agranulocytosis, aplastic anemia, and TEN
194
what type of anesthesia does not exacerbate MS?
epidural anesthesia
195
when is vasospasm most likely to occur after SAH?
2-14 days
196
what are the values for serum sodium and urine sodium in SIADH?
serum sodium <135
urine sodium >20
197
why do pain and paresthesias occur after a thalamic stroke?
due to latent brain plasticity
198
which artery and its branch supply the AV node?
right coronary artery and its branch, the posterior descending artery
199
in obesity, which lung volume and capacity are decreased the most?
expiratory reserve volume, which leads to decreased functional residual capacity
200
which medication causes intense perianal itching and pain?
dexamethasone
201
which opioid has effects via the kappa opioid receptor?
meperidine
202
what is the first-line medication for tachyarrhythmias in pregnant women?
adenosine
203
for a pt with acute CHF, which ventilation method is recommended?
NIPPV
Avoid intubation
204
what is an excitatory molecule that stimulates pain signal transmission?
glutamate
205
which medication requires a decreased dosage in a uremic pt?
midazolam
uremia causes decreased protein binding of drugs, which would cause an exaggerated effect, so dosage should be decreased
206
blood supply to SA node
right coronary artery
207
which muscles are used during forced expiration?
abdominal wall muscles (EO, IO, TA, rectus abdominis)
208
what enzyme does etomidate inhibit?
11β-hydroxylase
209
which adrenergic agonists cross the blood-brain barrier?
dexmedetomidine and clonidine
210
