10 Random Questions
Which of the following best explains the decreased effect of hyperventilation on cerebral blood flow when PaCO2 decreases below 20 mmHg?
- (A) Maximal constriction of cerebral vessels
- (B) Decreased cerebral perfusion pressure
- (C) Decreased cerebral metabolic rate for oxygen
- (D) Increased cardiac output
- (E) Increased cerebrospinal fluid pressure
Intraoperative heat loss in an unclothed, undraped patient is caused primarily by
- (A) conduction to colder objects
- (B) convective heat loss
- (C) insensible perspiration
- (D) radiant heat loss to the environment
- (E) respiratory tract water loss
During open reduction of a tibial fracture, a tourniquet cuff is applied around the proximal thigh and inflated to 300 mmHg. Which of the following is most likely to prevent pain and hypertension caused by the tourniquet?
- (A) Intravenous administration of fentanyl during subarachnoid block
- (B) Lumbar sympathetic block
- (C) Spinal anesthesia to a T6 sensory level
- (D) Obturator nerve block
- (E) General anesthesia
A 70-year-old man with stable angina is scheduled for cataract removal with a retrobulbar block. After injection of 5 ml of 0.75% bupivacaine, heart rate decreases from 90 to 55 bpm, and frequent premature ventricular contractions are noted on the EKG. These changes are most likely caused by
- (A) intravascular injection of bupivacaine
- (B) subarachnoid injection of bupivacaine
- (C) myocardial ischemia
- (D) oculocardiac reflex
- (E) retrobulbar hemorrhage
A patient with lumbar disk disease requires lumbar epidural injection of a corticosteroid for control of low back pain. Which of the following statements concerning this treatment is true?
- (A) Maximum effect occurs one hour after injection
- (B) Maximum effect occurs when drug concentration peaks in cerebrospinal fluid
- (C) Maximum effect occurs during the acute phase of the disease
- (D) The beneficial effect results primarily from sympathetic neurolysis
- (E) It is contraindicated if the patient has had prior surgical procedures on the lumbar disks
An isoflurane-specific vaporizer that is 25% full is mistakenly refilled with halothane, and the dial is set at 1.5%. Which of the following statements concerning this situation is true?
- (A) The gas mixture will contain equal partial pressures of halothane and isoflurane
- (B) The gas mixture will produce a greater depth of anesthesia than 1.5% isoflurane alone
- (C) The gas mixture will produce a greater depth of anesthesia than 1.5% halothane alone
- (D) The liquid mixture will have a higher vapor pressure than 1.5% halothane alone
- (E) The liquid mixture will have a higher vapor pressure if it is placed in a halothane-specific vaporizer
A healthy 10-kg child is flushed and restless after premedication with meperidine 15 mg and scopolamine 0.2 mg intramuscularly. His skin is warm and dry; temperature is 38°C, pulse is 130 bpm, and blood pressure is 90/60 mmHg. The most likely cause is
- (A) dehydration
- (B) idiosyncratic reaction to meperidine
- (C) malignant hyperthermia
- (D) neuroleptic malignant syndrome
- (E) scopolamine
To detect the delivery of a hypoxic gas mixture, the optimal location for an oxygen analyzer in this circle is
- (A) 1
- (B) 2
- (C) 3
- (D) 4
- (E) 5
Compared with morphine 5 mg administered epidurally at T12, morphine 5 mg administered intravenously is associated with
- (A) greater incidence of urinary retention
- (B) less intense analgesia
- (C) less nausea and vomiting
- (D) longer duration of analgesia
- (E) longer time to maximum analgesia
A 2.3-kg 1-day-old term infant requires repair of a gastroschisis. Which of the following combinations is most appropriate for intraoperative fluid management?
- (A) Dextrose 5% in water for maintenance and lactated Ringer's solution for replacement of third space losses
- (B) Dextrose 10% in water for maintenance and lactated Ringer's solution for replacement of third space losses
- (C) Lactated Ringer's solution for maintenance and replacement of third space losses
- (D) Lactated Ringer's solution for maintenance and albumin 5% for replacement of third space losses
- (E) Normal saline solution for maintenance and lactated Ringer's solution for replacement of third space losses