A patient is placed in the prone jackknife position for lumbar subarachnoid injection of tetracaine 10 mg in 10 ml of preservative-free sterile water. Which of the following results is most likely?
Mepivacaine 40 ml of a 1% solution with epinephrine 1:200,000 is injected into the brachial plexus sheath at the axilla after eliciting a paresthesia in the ulnar nerve distribution. Which of the following is most likely to remain intact?
(A) Adduction of the thumb
(B) Flexion at the wrist
(C) Sensation of the lateral forearm
(D) Sensation on the palmar surface of the lateral three and one half fingers
(E) Sensation on the palmar surface of the medial one and one half fingers
A 27-year-old man with a one-month history of quadriplegia at a C6 level is given general anesthesia for cystoscopy. During the cystoscopy, blood pressure suddenly increases to 220/120 mmHg. Further evaluation is most likely to show
A patient receiving monoamine oxidase inhibitor therapy for depression undergoes an emergency cholecystectomy. Which of the following is the best means of providing postoperative analgesia in this patient?
(A) Epidural analgesia using 0.25% bupivacaine
(B) Intravenous meperidine
(C) Epidural analgesia using meperidine
(D) Epidural analgesia using 1% lidocaine with epinephrine
(E) Intercostal analgesia using 1% lidocaine with epinephrine
A patient whose trachea is intubated develops partial airway obstruction two hours after induction of fentanyl, nitrous oxide, oxygen anesthesia. The anesthesiologist discontinues the nitrous oxide and controls ventilation, and there is gradual improvement during the next hour. No evidence of a respiratory disorder is found at the conclusion of the anesthetic. Which of the following is most likely?
(A) The endotracheal tube was in the right mainstem bronchus
(B) The patient had an unrecognized air embolism
(C) The patient had a nitrous oxide pneumothorax
(D) The endotracheal tube cuff narrowed the airway
A patient who is scheduled for emergency laparotomy for bowel obstruction has had oliguria for three hours. She has had hypertension for 10 years. Which of the following laboratory findings would indicate preoperative fluid challenge?
(A) Urine osmolality: 300 mOsm/L
(B) Urine specific gravity: 1.015
(C) Urine sodium concentration: 35 mmol/L
(D) Fractional excretion of sodium: 0.5
(E) Ratio of urine-to-plasma creatinine concentrations: 8
A 67-year-old man is undergoing total hip replacement under general anesthesia. He had a permanent endocardial VVI pacemaker placed two years ago for complete heart block, and since arrival in the operating room has been paced continuously. Use of the electrocautery causes the pacemaker to malfunction intermittently. The most appropriate management is to
(A) tape a magnet over the pacemaker generator and convert to asynchronous mode
(B) do nothing since the pacemaker is programmed to deal with this circumstance
(C) stop the surgeon from using the electrocautery
(D) limit the surgeon to 10 sec/min electrocautery bursts
(E) place the electrocautery indifferent lead as close as possible to the pacemaker
A 95-kg, 65-year-old woman receives sevoflurane and pancuronium during a laparoscopic cholecystectomy. Three minutes after administration of neostigmine 5 mg and atropine 1.2 mg, the twitch height returns to normal. Spontaneous tidal volume is 500 ml when the endotracheal tube is removed. In the PACU she reports dyspnea and appears distressed. Which of the following is the most likely cause of the respiratory distress?