Which of the following laboratory studies is most reliable in differentiating prerenal azotemia from acute tubular necrosis?
(A) Creatinine clearance
(B) Fractional excretion of sodium
(C) Urine/plasma urea ratio
(D) Urine sodium content
(E) Urine specific gravity
B
A patient has an anterior neck injury, hoarseness, labored respirations, subcutaneous emphysema, and laryngeal crepitus following a motor vehicle accident. Which of the following is the best method of securing the airway in this situation?
(A) Blind nasotracheal intubation
(B) Lightwand intubation
(C) Retrograde wire-guided intubation
(D) Tracheostomy
(E) Transtracheal jet ventilation
D
A 55-year-old man has quadriplegia after undergoing suboccipital craniotomy in the sitting position for treatment of acoustic neuroma. Which of the following is the most likely cause?
(A) Air embolism with the presence of a probe-patent foramen ovale
(B) Compression of the cervical cord related to neck flexion
(C) Jugular venous obstruction
(D) Postoperative tension pneumocephalus
(E) Sustained elevation of cerebral perfusion pressure
Postoperatively a 70-kg patient has a serum sodium value of 130 mEq/L. To increase this value to 140 mEq/L would require the administration of how much sodium in mEq?