38. C. Anesthetic considerations in patients with esophageal disease include the risk
of pulmonary aspiration, use of a DLT, invasive monitoring, intravenous access
sufficient for rapid fluid resuscitation, maintaining normothermia, and use of
transcutaneous pads for defibrillation if needed. The esophageal disease process
predisposes them to aspiration due to obstruction, altered motility, or abnormal
sphincter function. The risk of aspiration continues into the postoperative period.
Even though a DLT (Double lumen tube) facilitates surgical exposure, it is not
always required. Invasive monitoring with arterial line and central venous pressure
monitoring help guide hemodynamic management. However, a PAC (Pulmonary
artery catheter) is used only for patients with significant cardiac disease. Substernal
and diaphragmatic retractors used during the transhiatal approach to esophagectomy
can interfere with cardiac function. Surgeons hand can interfere with cardiac filling
while bluntly dissecting the esophagus from the posterior mediastinum. Since the
vagus runs very close to the esophagus, marked vagal stimulation can result in
profound bradycardia or even cardiac arrest—transcutaneous pads helps in these
situations. Hypothermia increases coagulopathy and increases cardiac arrhythmias
and should be avoided. The potential for rapid massive blood loss is significant as
the surgery is near the major blood vessels.
39. B. There has been a recent resurgence in LVRS, even though NETT, a trial of
usual medical therapy versus usual medical therapy plus LVRS, suggested lack of
efficacy of LVRS. Anesthetic considerations for LVRS include watching out for
pneumothorax caused by a ruptured bleb, use of double-lumen tubes to allow
selective ventilation and to facilitate surgery, using a lower FIO2
90%, limiting the degree of positive-pressure ventilation (<30 cm H2O peak
inspiratory pressure), prolonging the expiratory time, and early extubation. Total IV
anesthesia techniques using propofol and remifentanil or inhalational agents like
desflurane with short-acting neuromuscular blocking agents help facilitate early
extubation. If the patient cannot be extubated at the conclusion of the procedure, the
double-lumen tube is exchanged for a single-lumen tube to decrease airway
40. B. Equal pressure point refers to the point in the airway where intraluminal
pressure and extraluminal pressure (pleural) are the same. This is normally beyond
the 11th to 13th generation of bronchioles where cartilaginous support is absent. This
is the point where dynamic airway compression can occur—this refers to the
phenomenon in which collapsible membranous portion of the airway gets compressed
by the extraluminal pressure generated by a forced expiration. It is facilitated by the
large pressure drop across the airways causing a higher gradient between extra and
intraluminal pressures. Obstructive airway diseases predispose the patients to
dynamic airway compression. Elastase deficiency in emphysema causes decreased
elastic support in smaller airways. The bronchoconstriction and inflammation of
asthma predisposes to reversal of transmural gradients. Such patients usually adapt
by pursed-lip breathing and terminating the expiration early before functional residual
capacity falls below closing capacity (auto PEEP). However, the increase in lung
volume and slowing of expiration caused by such a maneuver helps to stent the
airway open. The increase in lung volume increases the intraluminal pressure and
dilates the airways, and the slow expiration reduces the decrease in pressure from the
alveoli to the mouth because lower driving pressures are sufficient for lesser flows.
This shifts the equal pressure point to the noncollapsible larger airways or to the
41. C. Any lesion causing a compression of the superior vena cava (SVC) and
impedes blood return from head and neck can cause venous engorgement and edema
of the head, neck, and arms. This is usually produced by a mediastinal tumor causing
compression of the mediastinal structures including the SVC. It can also be caused
by an occlusive thrombus in the SVC. Among the mediastinal neoplasms, lymphomas
are the most common causes for SVC syndrome. But other mediastinal tumors like
germ-cell tumors or pulmonary lesions with secondary lymphadenopathy may also be
responsible. These cases are very difficult as induction of anesthesia in a supine
position causes severe airway obstruction and cardiovascular collapse. The airway
obstruction is due to direct mechanical compression as well as mucosal edema.
Attempts should be made to decrease the size of the mass and the degree of
mediastinal compression should be made prior to elective surgery. This includes
radiation therapy, chemotherapy, and steroids. An empiric treatment with steroids
may be attempted prior to a tissue diagnosis in this 12-year old. A preoperative
echocardiogram can quantify the degree of compromise in cardiac function, presence
of a thrombus, or dynamic inflow obstruction in the presence of pericardial fluid. A
CT scan/MRI will help diagnose the presence of tracheomalacia/erosion and the level
of the lesion. If induction of general anesthesia is required in the presence of SVC
syndrome, awake fiberoptic intubation is the preferred method and inhalational
anesthetics can be used to attain a deep plane of anesthesia in a spontaneously
breathing patient after intubation. A rigid bronchoscope and ability to go on
cardiopulmonary bypass are other precautionary measures that can be taken. <CT>
1. Total normal cerebral blood flow (CBF) is
2. The factor associated with maximum increase in intracranial pressure (ICP) is
A. Increased central venous pressure to 14 mm Hg
B. Hypercarbia with PaCO2 of 50 mm Hg
C. Ventilation with positive end–expiratory pressure (PEEP) of 5 cm H2O
D. Bucking and coughing on endotracheal tube
3. Cerebral perfusion pressure (CPP) (mm Hg) in a patient with intracranial pressure
(ICP) of 12 mm Hg, central venous pressure (CVP) of 15 mm Hg, and mean arterial
pressure (MAP) of 70 mm Hg will be
4. Treatment of a patient with mannitol can lead to all the following, except
5. A patient is undergoing craniotomy for subdural hematoma. During the procedure,
the surgeon requests lowering the intracranial pressure. All the following can be
7. An absolute contraindication for electroconvulsive therapy (ECT) is
8. Signs of air embolism in a patient include all, except
9. A 65-year-old male is undergoing surgery for medulloblastoma in the posterior fossa
of brain. Approximately 1 hour into surgery you notice arrhythmias on the monitors.
10. Nitrous oxide should be avoided in patients with
11. The following fluid should be avoided in a patient undergoing craniotomy
12. Most sensitive method to detect air embolism is
A. Transesophageal echocardiogram (TEE)
B. Decreased end-tidal carbon dioxide
C. Increased end-tidal nitrogen
13. Best measure to reduce cerebral oxygen consumption includes
A. Administration of barbiturates
14. All of the following decrease cerebral blood flow (CBF), except
15. In a patient undergoing craniotomy, the transducer of arterial line should be zeroed at
C. Level of external auditory meatus
16. Jugular venous oxygen saturation
A. Estimates oxygen extraction
B. Is unaffected by systemic hypoxia
C. Involves placement of catheter through inferior vena cava
D. Monitors global oxygenation of both cerebral hemispheres
17. The effect of ischemia on somatosensory-evoked potentials (SSEPs) is
A. Decreased latency, decreased amplitude
B. Increased latency, increased amplitude
C. Decreased latency, increased amplitude
D. Increased latency, decreased amplitude
18. A patient with spinal injury, sustained 3 hours ago, comes to the OR for exploratory
laparotomy. Anesthetic management of the patient includes which of the following?
A. Rapid-sequence induction with succinylcholine
B. Hypothermia for better neurologic outcome
C. Managing autonomic hyperreflexia
19. The electrophysiological monitor most resistant to anesthetic agents is
A. Somatosensory-evoked potentials
C. Brain-stem auditory-evoked potentials
20. The most reliable monitor for neurologic monitoring in a patient undergoing carotid
B. Jugular venous oxygen saturation
21. Anesthetic management of a patient with multiple sclerosis (MS) includes
D. Use of succinylcholine can result in hypokalemia
22. All the following are true for Guillain–Barré syndrome (GBS), except
A. Respiratory paralysis is frequent complication
B. Presence of labile autonomic nervous system
23. True statement about autonomic hyperreflexia is
A. Lesions below T10 is responsible for the reflex
B. It can be treated with deep general anesthetic
C. It is associated with vasoconstriction above the site of injury
D. It can be provoked by thermal stimulation
24. A 16-year-old patient with acute lysergic acid diethylamide (LSD) intoxication and
head injury comes to emergency room. All the following can be used in anesthetic
25. A 25-year-old patient with severe depression is undergoing an electroconvulsive
therapy (ECT). The duration of seizure can be increased by
A. Hypoventilating the patient
B. Hyperventilating the patient
C. Administering succinylcholine
26. All of the following are contraindications of electroconvulsive therapy (ECT),
C. Raised intracranial pressure
27. True statement regarding cerebral physiology is
A. Normal cerebral metabolic oxygen consumption is 5 mL/100g/min
B. Normal Intracranial pressure (ICP) is approximately 15 mm Hg
C. Normal cerebral blood flow (CBF) is 50 mL/100g/min
D. Cerebral autoregulation is strictly maintained at blood pressures between 60
28. True statement about cerebrospinal fluid (CSF) is
A. It is formed in the third ventricle
B. It is absorbed in arachnoid granulations present in fourth ventricle
C. Total volume of CSF is about 150 mL
D. Major mechanism of formation is by passive diffusion of ions
29. A precordial Doppler can detect a minimal of ___ mL of intracardiac air:
30. The only inhalational anesthetic that can cause an isoelectric EEG among the
31. Intraoperative anesthetic management of a patient undergoing cerebral aneurysm
B. Mannitol for facilitating surgical exposure
C. Maintaining mild hypothermia
D. Patient remaining intubated for 24 hours postoperatively
32. Which of the following types of neuromonitoring can be done in a patient undergoing
transsphenoidal resection of a pituitary tumor?
33. The drug of choice for treating nausea and vomiting in a patient with parkinsonism
34. All the following anesthetic agents can cause seizurelike activity on the
electroencephalogram (EEG), except
35. The neuromuscular blocking agent relatively contraindicated in a patient with raised
intracranial pressure (ICP) is
36. The afferent input for somatosensory-evoked potentials is carried by which spinal
37. You are called to evaluate a 50-year-old patient for brain death. All the following
are criteria for brain death, except
C. Presence of spinal reflexes
38. A 30-year-old male is found unresponsive outside a supermarket. The emergency
response team finds him in ventricular fibrillation. After 10 minutes of CPR, the
emergency response team is successful in reviving the patient. In the emergency
room, it is decided to cool the patient to 34°C from 37°C. By this measure, the
cerebral metabolic demand will decrease by
39. All the following are relative contraindications to a sitting craniotomy, except
A. Right-to-left cardiac shunt
40. An 80-year-old female comes to the ER with closed distal radial fracture. On further
questioning, she gives a history of stroke about 2 weeks ago. How long should one
wait before it can be assumed that her risk of perioperative stroke is same as a
41. A 28-year-old male is being treated in the ICU for raised intracranial pressure (ICP).
All the following measures can aid in decreasing ICP quickly, except
B. Hyperventilation to PaCO2 of 30 mm Hg
D. Head elevation to 30 degrees
42. Which of the following agents will have the least effect on somatosensory-evoked
43. Signs and symptoms of raised intracranial hypertension include all the following,
44. Etomidate in a dose of 0.2 mg/kg can lead to all the following, except
A. Abolish ventilatory response to carbon dioxide
B. Increase amplitude and latency of somatosensory-evoked potentials (SSEPs)
C. Decrease cerebral metabolic oxygen demand
D. Decrease cerebral blood flow (CBF)
45. The most important factor governing cerebral blood flow (CBF) is
A. Cerebral metabolic oxygen demand
D. Cerebral perfusion pressure
46. The following graph depicts the relationship between cerebral perfusion and
47. The following graph depicts the relationship between cerebral perfusion and
48. A 45-year-old male is seen in the preadmission testing for pituitary adenoma
resection surgery. All the following would be expected if this adenoma was causing
49. The fastest measure to decrease intracranial pressure (ICP) in a patient is
50. Therapy for cerebral vasospasm includes
A. Hypertension, hypervolemia, hemodilution
B. Normotension, euvolemia, hypocarbia
C. Hypotension, hypovolemia, hypocarbia
D. Hypertension, hypervolemia, hypocarbia
1. B. Normal total CBF is about 50 mL/100 g/min. CBF below 20 mL/100 g/min is
associated with cerebral ischemia. CBF is modulated by various factors, which
, blood pressure, intracranial pressure, etc.
2. D. Intracranial pressure is supratentorial CSF pressure measured in the lateral
ventricles or cerebral cortex. Normal ICP is 10 mm Hg or less. Between PaCO2
values of 20 and 80 mm Hg, CBF increases by 1 mL/100 g/min and cerebral blood
volume increases by 0.05 mL/110g/min per mm Hg increase in PaCO2
CVP and adding PEEP will minimally increase ICP by affecting venous return.
Coughing and bucking can cause a much higher increase in ICP (acute increase) than
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