After inflation of both the tracheal and endobronchial cuffs of a left-sided double-lumen tube, the following are noted on auscultation of the chest: Left lumen clamped --> Breath sounds absent bilaterally; Right lumen clamped --> Breath sounds present on left only; Both lumens open --> Breath sounds present on left only. The most appropriate action is to
(A) decrease the endobronchial cuff volume
(B) decrease the tracheal cuff volume
(C) reinsert the tube, rotating it 180 degrees to the right
(D) suction both lumens
(E) withdraw the tube slightly and repeat the auscultory maneuvers
Pain and spasm due to injury of the deltoid muscle is most effectively relieved by
(A) axillary block
(B) cervical sympathetic block
(C) interscalene brachial plexus block
(D) paravertebral block at C4
(E) superficial cervical plexus block
C
A 54-year-old man is scheduled for open reduction of a fracture sustained when he jumped from a burning building. The carboxyhemoglobin concentration is 25%. Which of the following is the most reliable indicator of adequate oxygenation during general anesthesia?
(A) PaO2 of 300 mmHg
(B) pH of 7.38 with a PaCO2 of 41 mmHg
(C) Mixed venous PO2 of 45 mmHg
(D) Oxyhemoglobin saturation of 100% measured by co-oximeter
An EKG shows ventricular tachycardia in a patient with a heart rate of 160 bpm and a blood pressure of 90/60 mmHg. The best initial therapeutic maneuver prior to cardioversion is
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
During isoflurane anesthesia, a 45-year-old patient with chronic asthma has wheezing, prolonged expiration, sinus tachycardia of 120 bpm, and premature ventricular contractions. Preoperative medication included cromolyn and theophylline. The most appropriate treatment is to administer