ANESTHESIA

Question 1

procedures under moderate sedation

Answer 1

Joint Commission requires patients to be managed in the same manner as if an anesthesiologist were providing sedation.

history and physical examination be performed before the procedure.

Airway cart and resuscitation equipment must be nearby.

All patients should be monitored after the procedure in an appropriate recovery facility until the effects of the medications have worn off.

Finally, a person dedicated to patient monitoring is required other than the physician performing the procedure.

In moderate sedation, this can be a person assisting with the procedure, provided he or she has the ability to completely focus on the patient’s airway and cardiopulmonary status, if necessary.

In a patient undergoing deep sedation, this person must be dedicated solely to patient monitoring and must not participate in assistance with the procedure being performed.

Question 2

Richmond Agitation–Sedation Scale (RASS;

Answer 2

allows a specific level of sedation to be targeted regardless of the medication used, thus avoiding both under- and oversedation.

Question 3

Sedation in the elderly intubated patient, particularly those with preexisting cognitive dysfunction

Answer 3

Haloperidol should be used for the treatment of delirium once it occurs but is not an appropriate sedating agent.

When compared with dexmedetomidine, both midazolam and lorazepam are associated with an increase in delirium and a longer time on the ventilator.

Question 4

dexmedetomidine uses advantages and comparisons

Answer 4

Precedex

alpha-2 adrenergic agonist that is more selective than clonidine.

may have a neuroprotective effect.

provide sedation without causing respiratory depression

It prolongs the duration of anesthetic and motor block by local anesthetics.

It increases the number of days free from coma and delirium compared with benzodiazepines.

It failed to show a shorter duration of intubation or length of stay, however, compared with patients receiving propofol in the intensive care unit.

It can also be used as a sedative/anesthetic agent for surgical and endoscopy procedures in both adult and pediatric patients.

BUT cardiac surgery patients have a higher incidence of hypotension compared with propofol.

Question 5

Malignant hyperthermia (MH) is a hypermetabolic response to

Answer 5

potent inhalation agents:
halothane, sevoflurane, desflurane)

and

the depolarizing muscle relaxant succinylcholine.

Question 6

Malignant hyperthermia he highest incidence is in

Answer 6

young people, with a mean age of all reactions of 18.3 years.

It has been found that children younger than 15 years comprised 52.1% of all reactions.

Question 7

Malignant hyperthermia Initial treatment

Answer 7

intravenous dantrolene

cold intravenous fluids and icepacks if the core temperature is increasing,

Dantrolene should be continued until normalization of heart rate, pCO2, and muscle tone and until core temperature is less than 38°C.

Question 8

Malignant hyperthermia testing

Answer 8

Blood testing may be used to look for variants in the ryanodine receptor type 1 gene (RYR1).

If a genetic variant is found, relatives can then be evaluated for their risk of malignant hyperthermia.

Question 9

Malignant hyperthermia in outpatient surgery center

Answer 9

total intravenous anesthesia with or without regional analgesia, an MH-susceptible patient can be safely treated

and

discharged home 2 hours after the end of a nontriggering anesthetic.

Question 10

The most common signs of anaphylaxis during surgery are

Answer 10

cutaneous flushing,
difficult to ventilate
wheezing,
hypotension

Question 11

If anaphylaxis Management consists of

Answer 11

The anesthetic should also be discontinued,

100% oxygen

Intravenous fluids,

epinephrine,

steroids,
bronchodilators
histamine antagonists

Prolonged support and intensive care unit monitoring may be required until symptoms are resolved.

Question 12

most common cause of anaphylaxis during surgery

Answer 12

Muscle relaxants are by far the most common accounting for 69% of cases!

Latex is the second most common etiology, accounting for 12%.

Antibiotics, hypnotics, colloids, opioids, isosulfan blue, and “other substances” are far less commonly reported as inciting agents.

Question 13

The most common signs of local anesthesia overdose include

Answer 13

tremors,
shivering,
muscle twitching.

Question 14

most common serious side effect of lidocaine toxicity

Answer 14

tonic–clonic seizure.

result from disinhibition of neurons in the central nervous system.

Left untreated, the reaction can progress to sedation, drowsiness, lethargy, and respiratory depression.

Question 15

side effects with eceedingly high dose of lidocaine

Answer 15

With exceedingly high does,

cardiac toxicity

ectopic rhythms

bradycardia.

Question 16

what decrease the dose-producing toxicity from lidocaine

Answer 16

Hypoxia,

acidosis,

hyperkalemia

Question 17

Maximal dose of lidocaine for a 70 kg

Answer 17

person is 310 mg (4.5 mg/kg)

Maximal dose of lidocaine with epinephrine for a 70 kg person is 490 mg (7 mg/kg)

Question 18

Epidural anaesthesia what areas of the body can it cover

Answer 18

procedures involving the 
lower limbs, 
perineum, 
pelvis, 
abdomen, 
thorax.

Question 19

sympathetic block levels covered

Answer 19

sympathetic block usually extends 1–2 levels higher than sensory block.

Epidural anesthetic blockade of sympathetic outflow (T5–L1) to the gastrointestinal tract leads to predominance of vagus and sacral parasympathetic outflow. This results in active peristalsis and relaxed sphincters, and a small, contracted gut. Splenic enlargement (2- to 3-fold) also occurs.

Question 20

Epidural anaesthesia anticipated physiologic effects

Answer 20

Vasodilatation of resistance and capacitance vessels occurs, causing relative hypovolemia and tachycardia, with a resultant drop in blood pressure

adrenals is blocked, preventing the release of catecholamines.

If blockade is as high as T2, sympathetic supply to the heart (T2–5) is also interrupted and may lead to bradycardia.

The overall result may be inadequate perfusion of vital organs, and measures are required to restore the blood pressure and cardiac output, such as fluid administration and the use of vasoconstrictors.

Urinary retention is a common problem with epidural anesthesia, and a severe drop in blood pressure may affect glomerular filtration in the kidney if sympathetic blockade extends high enough to cause significant vasodilatation.

Question 21

safest regional block

Answer 21

The axillary block is the safest of the 4 approaches to the brachial plexus,

because it does not risk paresis of the phrenic nerve, nor does it have the potential to cause pneumothorax.

Question 22

anatomy of axillary block

Answer 22

In the axilla, the nerves of the brachial plexus and the axillary artery are enclosed together in a fibrous sheath

that is a continuation of the deep cervical fascia.

The easily palpated axillary artery thus serves as a reliable anatomical landmark for this block, and the injection of local anesthetic close to this artery frequently leads to a good block of the brachial plexus.

Question 23

The reported incidence of complications after peripheral nerve block is

and what are complications

Answer 23

generally low and varies from 0% to 5%.

Mechanical injuries from needle misplacement represent a significant source of complications.

Injuries to peripheral nerves after intrafascicular injection of therapeutic and other agents are well documented.

Nerve injury after intraneural injection varies from minimal damage to severe axonal and myelin degeneration.

Several studies have documented that intrafascicular injection is the main determinant of nerve injury.

Question 24

pharm of local anesthetics

Answer 24

Local anesthetics are weak bases.

In an acidic environment, the drug is ionized and less effective, because it cannot enter the cell to effectively block nerve conduction.

Sodium ion flux across plasma membranes is responsible for initiation and propagation of action potentials in axons.

Local anesthetics reduce sodium ion flux by binding to voltage-gated sodium channels and preventing these channels from conducting sodium ions during depolarization.

Unintended binding of local anesthetic agents to off-target sodium channels is believed to be the cause of local anesthetic systemic toxicity (LAST).

Question 25

most frequent and prominent early warning signs of local anesthetic toxicity

Answer 25

Central nervous system symptoms are the of LAST.

Question 26

treatment of local toxicity central nervous system manifestations

Answer 26

Minor:
vertigo or tinnitus:

do not routinely require any intervention with drug treatment, because these symptoms will often promptly dissipate if no additional local anesthetic is administered.

generalized seizures

patients should be protected from harming themselves and provided adequate ventilation and oxygenation.

Endotracheal intubation may be necessary.

Seizures can usually be terminated with small doses of 
midazolam (1–5 mg), 
propofol (50–100 mg), 
or 
any other sedative hypnotic agent 
(barbiturates or benzodiazepines).

Question 27

Postoperative cognitive dysfunction

Answer 27

postoperative memory or thought process impairment that can be corroborated by neuropsychological testing.

2 distinct patterns.

Transient perioperative delirium is defined:

acute change in mental status associated with inattention and fluctuating level of consciousness over the course of the day. The overall incidence of postoperative delirium in all age groups is 5–10% but approaches 45% in the elderly.

Although often of short duration, patients with postoperative delirium have an increased mortality and prolonged hospitalization.

A second pattern of impaired cognitive performance:

may present within the first week after surgery but can persist for a year or more.

Affecting upward of 30% of postoperative patients older than 60 years, the incidence of this form of POCD increases with age.

Variables confounding its development include educational and preoperative activity level, duration of anesthesia, and the presence of postoperative infection.

An association with longer, more complex surgeries suggests anesthetic agents as obvious potential factors, but there is no clear evidence supporting this hypothesis. Further, the incidence is equivalent between patients receiving volatile inhalation general anesthetics or regional anesthesia !!!

Interestingly, induction of central nervous system proinflammatory cytokines and activation of the immune system have been associated with cognitive decline in preclinical animal studies, suggesting an avenue of investigation aimed at prevention and treatment. POCD is reversible with time.

There is no evidence that surgery aggravates existing Alzheimer disease or triggers its onset.

Question 28

neuraxial anesthesia in patients receiving antithrombotic drugs

Answer 28

The CT angiogram demonstrates evidence of bilateral pulmonary emboli. This patient requires anticoagulation therapy for treatment of her symptomatic pulmonary emboli. The presence of an epidural catheter is problematic, because neuraxial anesthesia in patients receiving antithrombotic drugs is associated with an increased risk of spinal epidural hematoma. After enoxaparin 30 mg twice daily was introduced for thromboprophylaxis in the United States, an alarming number of cases of spinal epidural hematoma, some with permanent paraplegia, were reported, triggering a warning from the US Food and Drug Administration. Current guidelines direct that regional anesthesia in patients receiving full anticoagulation treatment is contraindicated. This applies to the use of both low molecular weight heparin (LMWH) and intravenous unfractionated heparin. For patients with an epidural catheter in place who require therapeutic anticoagulation, the epidural catheter should be removed. To avoid bleeding complications, there should be a time interval between removal of the catheter and the start of anticoagulation therapy. Unfractionated heparin may be started 1 hour after catheter removal. LMWH may be started 4 hours after catheter removal.
Pulmonary embolectomy would not be indicated in this patient, who, although symptomatic, is not hemodynamically compromised. Placement of a vena cava filter would not be indicated unless the patient had an excessive risk of bleeding postoperatively or developed a recurrent pulmonary embolism while receiving therapeutic anticoagulation. Administration of warfarin is contraindicated when an epidural catheter is in place. Removing the epidural catheter and starting the patient on anticoagulation therapy with warfarin is also contraindicated, because of the need for immediate therapeutic anticoagulation in this setting.

Question 29

Propofol i

Answer 29

potent respiratory depressant and should be used with extreme caution in the nonintubated patient.

It has a rapid onset and short duration of action and can be easily titrated.

This is particularly beneficial in the traumatic brain injury patient, where a neurologic examination is intermittently desired.

It causes a reduction in systemic vascular resistance and has a negative effect on cardiac output; therefore, it can cause hypotension, particularly in the hypovolemic patient.

Question 30

propofol infusion syndrome

Answer 30

syndrome consists of

cardiac failure,
rhabdomyolysis,
severe metabolic acidosis,
renal failure.

Even when large doses are used briefly, if a patient receiving propofol develops unexplained lactic acidosis, rhabdomyolysis, or renal failure, propofol infusion should be stopped, and an alternative sedating drug should be considered.

Treatment is primarily supportive in nature.

Question 31

Etomidate is a frequently used because of what advantages

Answer 31

short-acting hypnotic for endotracheal intubation requiring rapid sequence intubation (RSI).

Etomidate is especially ideal for RSI in hypotensive patients because it has minimal effects on hemodynamics.

It does not liberate histamine.

little respiratory depression.

useful in patients with brain injury. It reduces cerebral metabolic rate, which is associated with a decrease in intracranial pressure.

A

Question 32

side effect of etomidate

Answer 32

adrenal suppression.

impairing cortisol production.
(Etomidate inhibits 11-beta-hydroxylase, )

A single dose of etomidate may show adrenal suppression for 72 hours.

A continuous infusion of etomidate results in adrenal dysfunction.

After 5 days of continuous infusion, mortality increases from 25% to 44%, most commonly due to infectious causes.

This adrenal suppression has raised questions regarding etomidate’s safety in septic patients.

However, current information suggests its beneficial cardiovascular effects may outweigh the adrenal suppression effect when used as a single dose for intubation.

Question 33

Risk factors for development of delirium include what meds

Answer 33

analgesics, benzodiazepines, and antihistamines.

Question 34

treatment of delirium is

Answer 34

treating contributing medical conditions, removing deliriogenic medications, performing daily sedation holidays with spontaneous breathing trials to reduce the exposure to sedatives, providing environmental control (reestablishing normal sleep cycle), and ensuring cognitive reorientation (increasing daytime interaction, increasing mobility, and replacing eyeglasses and hearing aids).

If the delirious patient requires additional treatment, the Society of Critical Care Medicine guidelines recommend haloperidol as the drug of choice.

Haloperidol is a dopamine-2 receptor antagonist and a typical antipsychotic that does not produce respiratory depression.

Haloperidol is the most widely used neuroleptic agent for delirium.

Newer atypical antipsychotics are also frequently used and may prove to be equally efficacious in the treatment of delirium.

Question 35

The laryngeal mask airway goes where

Answer 35

designed to form a seal around the larynx, with the mask conforming to the shape of the hypopharynx.

Question 36

The LMA has several advantages over endotracheal intubation and facemask ventilation.

Answer 36

secures the airway

provides better ventilation than a facemask.

low risk of aspiration equivalent to endotracheal intubation!

less experience and expertise than endotracheal intubation - can be used by emergency medical technicians

The LMA can be placed with or without using muscle-relaxing agents, but airway reflexes need to be reduced.

The American Society of Anesthesiologists recommends LMA as an alternative strategy for patients with a difficult airway!
either as a primary means of obtaining an airway or as a means to allow a conduit for endotracheal intubation.

Question 37

The LMA is limited in that it is not useful in what situations

Answer 37

elevated inspiratory pressures are required.

not recommended when the risk of regurgitation is high or prolonged ventilation is required.

Question 38

Postdural puncture headache ssx and pathophys

Answer 38

can occur after administration of spinal or epidural analgesia.

The reported incidence varies but is generally thought to occur in 1–5% of cases of neuraxial analgesia.

Postdural puncture headache occurs when cerebrospinal fluid (CSF) leaks through a rent in the dura at a rate greater than CSF production, resulting in LOW CSF pressure.

Patients with postdural puncture headaches typically experience frontal or occipital headaches within 12 to 24 hours after the procedures.

The headache is worse when in the upright position and improves as a patient lays flat supine.

Associated symptoms can include nausea, vomiting, dizziness, tinnitus, and visual changes.

Question 39

Postdural puncture headache that occurs after lumbar puncture often responds to

Answer 39

therapy with bed rest and oral analgesics.

Question 40

postdural puncture headache after placement of an epidural catheter.
For a patient who does not respond to conservative therapy within 24 hours

Answer 40

use of epidural blood patch should be considered.

Placement of an epidural blood patch involves the injection of 10–20 mL of freshly drawn untreated autologous whole blood into the epidural space.

This maneuver results in an immediate increase in CSF pressure as well as an occlusion of the rent within the dura. Most patients will experience a rapid resolution of their headaches.

The blood patch is effective in more than 90% of cases, although some patients may require more than 1 application to achieve a lasting effect.

Complications directly attributable to the epidural blood patch are rare, and the epidural blood patch is not associated with an increased risk of spinal cord compression or injury.

Question 41

Local anesthetics are believed to have what physio effects that benefit the patient

Answer 41

reduce central nervous system stimulation, and this is responsible for the beneficial effects on the gastrointestinal, metabolic, and immune systems.

abdominal or thoracic procedures, epidural analgesia had a beneficial effect on pulmonary complications, lung function, and gas exchange!

There was a significant decrease in the incidence of pneumonia [odds ratio (OR) = 0.54; 95% confidence interval (CI) = 0.43–0.68] and a reduced need for reintubation!

Despite a higher incidence of postoperative hypotension, epidural analgesia significantly reduced the risk of postoperative myocardial infarction (OR = 0.55, 95% CI = 0.37–0.84)!

BUT Despite the lower myocardial infarction rate, there was no overall effect on postoperative mortality (OR = 1.01, 95% CI = 0.7–1.44).

In addition, there was no effect on postoperative nausea or renal insufficiency.

Question 42

Sedation Routine patient monitoring usually includes

Answer 42

Despite the lack of data on the effectiveness of pulse oximetry in decreasing procedural complications, its use is recommended in all patients.

intermittent blood pressure monitoring,
direct observation of adequate ventilation and level of consciousness by a designated person other than the endoscopist performing the procedure.

Continuous EKG monitoring is recommended by the American Society of Anesthesiologists (ASA) for patients with significant cardiovascular disease, arrhythmias, a history of significant pulmonary disease and elderly patients and when a prolonged procedure is anticipated.

Its role or necessity in monitoring healthy patients is unclear.

According to ASA guidelines, supplemental oxygen administration should be considered during moderate sedation

All patients should be monitored by a trained person other than the endoscopist.

If moderate sedation is used, that person may also perform additional tasks of short duration that may be interrupted.

If deep sedation is used, that person must be free of all procedural responsibilities outside of direct patient monitoring.

Monitoring of exhaled carbon dioxide by capnography should be considered in high-risk patients and when ventilation cannot be directly observed.

Appropriate drugs for reversal of the agents used for sedation must be readily available. Naloxone is an opioid antagonist. Flumazenil is used to reverse benzodiazepine overdose.

Question 43

acute pain from rib fractures best evidence practice

Answer 43

epidurals and paravertebral and intercostal nerve blocks.

Epidural analgesia decreases the morbidity and mortality associated with these injuries!

Evidence for the use of paravertebral and intercostal nerve blocks has demonstrated that each technique is safe and effective in older patients.

Using regional analgesia improves lung function with a notable improvement in vital capacity and respiratory effort.

The risk of pneumothorax with intercostal rib block is 1.4% for each nerve blocked.

Question 44

Opioids produce varying degrees of histamine release, which is greatest with

Answer 44

morphine and meperidine.

Methadone and codeine have lesser degrees of histamine release;

Question 45

Opioids least likely to release histamine

Answer 45

fentanyl i

the preferred agent for the acutely ill or injured surgical patient in need of pain control in whom volume status is not optimized.

Optimizing volume status and slowing the rate of infusion may blunt histamine-induced hypotension.

Question 46

The Joint Commission’s Universal Protocol core minimum components of a surgical timeout include

Answer 46

correct patient identification,

the correct site of surgery,

the correct procedure to be done.

when 2 or more procedures are to be done, a surgical timeout is required for each procedure performed if the person performing the procedures changes.

(“Further, this commonly occurs before incision but after induction of the anesthetic agent.”

Question 47

The American College of Cardiology/American Heart Association guidelines on perioperative cardiovascular evaluation for noncardiac surgery highlight 3 areas that must be assessed to determine a patient’s risk of a cardiac event:

Answer 47

(1) patient-specific clinical variables,
(2) exercise capacity
(3) surgery-specific risk.

Question 48

Clinical predictors of a major increased risk that require intensive evaluation or management preoperatively include active cardiac conditions:

Answer 48

1. Unstable coronary syndromes
   • Unstable or severe angina
   • Recent myocardial infarction

    -Acute myocardial infarction (myocardial infarction documented 7 days but 2.0 mg/dL)

Question 49

The following minor clinical predictors, if more than 1 is present, may lead to a higher suspicion for coronary heart disease:

Answer 49

1. Advanced age (>70 years)
   
   2. Abnormal electrocardiogram (left ventricular hypertrophy, left bundle branch block, ST-T wave abnormalities)
   3. Rhythm other than sinus (such as atrial fibrillation)
   4. Uncontrolled systolic hypertension
      However, these have not been proven to be independent predictors of increased risk.

Question 50

the greatest likelihood of predicting perioperative coronary events.

Answer 50

predicted risk for all serious complications independent of all other patient characteristics examined.

poor exercise tolerance, defined as :

the inability to walk at least 3 blocks
or
climb 2 flights of stairs, has Poor exercise

Question 51

specific cardiac risk of the procedure.

Answer 51

stratified into 3 groups:

1. High risk: aortic/major vascular, peripheral arterial surgery (NOT CEA)
2. Intermediate risk: intraperitoneal/intrathoracic surgery, orthopedic surgery (risk of cardiac death/nonfatal myocardial infarction is 1–5%)
3. Low risk: ambulatory surgery, endoscopic procedures, skin/soft tissue surgery (risk of cardiac death/nonfatal myocardial infarction is <1%)

Question 52

use of iv dexamethasone for lap chole

Answer 52

proven benefit of dexamethasone on postoperative nausea and vomiting in laparoscopic cholecystectomy.

The efficacy of different antiemetic regimens in patients undergoing laparoscopic cholecystectomy has been evaluated. Placebo-controlled trials have shown serotonergic antagonists, such as ondansetron, to be effective in reducing PONV.

Question 53

lap chole analgesia data

Answer 53

Preincisional local anesthesia to wounds and peritoneum should be used. Thirteen trials examined the use of local anesthesia during laparoscopic cholecystectomy.

Preincisional local anesthesia was shown to be superior to postincisional infiltration.

Two trials showed that the combination of intraperitoneal and incisional local anesthesia is superior to either method alone and reduces PONV.

Question 54

Administration of a local anesthetic before making an operative incision

Answer 54

is thought to interfere with nociceptive signals from the incision site and to prevent central nervous system hypersensitization.

studies failing to demonstrate clinical efficacy.

Preemptive pain control is not demonstrated with current regimens of nociceptive blockade.

Question 55

US Food and Drug Administration (FDA) pharmaceutical pregnancy categories.
Lidocaine

Answer 55

Lidocaine is a pregnancy category B drug.

Animal studies have failed to reveal evidence of fetal harm.

There are no controlled data in human pregnancies.

Use in labor and delivery may result in fetal and neonatal toxicity !!

Lidocaine should only be given during pregnancy and in labor and delivery when need is clearly established.

Question 56

Bupivacaine is a pregnancy category

Answer 56

C drug!

Animal studies have revealed evidence of embryolethality!! at doses exceeding the maximum recommended daily human dose!

only for use during pregnancy only when benefit outweighs risk.

This recommendation does not exclude the use of bupivacaine at term for obstetrical anesthesia or analgesia.

Question 57

Acetaminophen in oral or rectal form is a pregnancy category

Answer 57

B category drug.

Animal studies have failed to reveal evidence of fetal harm.

It is routinely used for short-term pain relief and fever in all stages of pregnancy.

Acetaminophen is believed to be safe in pregnancy when used intermittently for short durations.

Question 58

Hydrocodone is a pregnancy category

Answer 58

C drug.

When given to pregnant hamsters, a single dose of hydrocodone increased the risk of birth defects, including cranial defects!

Limited human studies also indicate that hydrocodone may increase the risk of similar birth defects in humans.