A 157 cm (5 ft 2 in), 180-kg, 40-year-old woman has a PaO2 of 65 mmHg, a PaCO2 of 38 mmHg, and a pH of 7.43 while breathing room air preoperatively. The most likely cause of these values is
(A) decreased hypoxic ventilatory drive
(B) higher than normal oxygen extraction from blood
(C) lower than normal cardiac output
(D) lower than normal functional residual capacity
A 58-year-old man undergoes repeat coronary artery bypass grafting. Which of the following is LEAST likely to decrease the need for exogenous blood transfusion?
(A) Cell saver blood collection before and after cardiopulmonary bypass
(B) Epsilon-aminocaproic acid administered during cardiopulmonary bypass
(C) High-dose aprotinin administered during cardiopulmonary bypass
(D) Tranexamic acid infusion during cardiopulmonary bypass
(E) Desmospressin administered after cardiopulmonary bypass
E
A 40-year-old man is scheduled for emergency laparotomy for bowel obstruction. He is nauseated but has not vomited. Which of the following drugs administered intravenously preoperatively will decrease the risk for pulmonary aspiration?
(A) Atropine
(B) Droperidol
(C) Metoclopramide
(D) Ranitidine
(E) None of the above
E
Which of the following statements concerning the pharmacokinetics of local anesthetics is true?
(A) Decreased molecular weight is associated with decreased incidence of allergic reactions
(B) Decreased protein binding is associated with decreased systemic toxicity
(C) Increased ionization is associated with increased placental transfer
(D) Increased lipid solubility is associated with faster onset
(E) Presence of an ester linkage is associated with increased duration of action
At induction, the inspired concentration of a volatile anesthetic agent will approach its dialed concentration most rapidly if
(A) the anesthetic circuit is made of rubber rather than polyethylene
(B) the patient breathes more deeply
(C) fresh soda lime is used
(D) fresh gas flow rate is increased
(E) nitrous oxide is added to the inspired gas mixture
D
A woman at 39 weeks' gestation has been in labor for 12 hours. She has had nausea and vomiting for the past eight hours. Maternal arterial blood gas values are PaO1 85 mmHg, PaCO2 31 mmHg, and pH 7.50. Which of the following is the most likely cause of fetal distress occurring at this time?
(A) Hypocarbia-induced placental ischemia
(B) Impaired fetal oxyhemoglobin dissociation
(C) Shift to the left of the maternal oxyhemoglobin dissociation curve
A patient who is scheduled for emergency debridement of an infected wound on the sole has trismus, rigidity of facial muscles, and spasms of the intercostal muscles, diaphragm, and extremities. During anesthesia, this patient is at increased risk for each of the following EXCEPT
(A) hypotension
(B) hypertension
(C) tachycardia
(D) diaphoresis
(E) hypothermia
E
A patient sustains cardiac arrest while being mechanically ventilated. Which of the following is the most likely effect on PetCO2?
(A) Gradual increase with the duration of asystole
(B) Maintenance of the prearrest value
(C) Abrupt decrease below the prearrest value
(D) Decrease when thoracic compression is started
(E) Gradual decrease independent of the ventilator cycle
A woman is undergoing a repeat cesarean delivery at term following a normal pregnancy. Anesthesia consists of thiopental 250 mg, succinylcholine infusion (180 mg in 20 minutes), nitrous oxide and oxygen (7:3 L/min) until delivery. Twenty minutes after the incision a floppy newborn with a 1-minute Apgar score of 5 is delivered. The most likely explanation for the infant's condition is