An 86-kg, 67-year-old man is undergoing a second coronary artery bypass operation. Five minutes after administration of protamine, blood pressure is 69/40 mmHg, pulmonary artery pressure is 65/42 mmHg, and the cardiac output measured by thermodilution is 2.3 L/min. Which of the following is the most likely cause of these findings?
(A) Allergy to fish
(B) Increased plasma thromboxane concentration
(C) Increased plasma histamine concentration
(D) Insulin-dependent diabetes mellitus
(E) IgE antibodies to protamine
B
Which of the following is the most important function of temperature compensation in anesthetic vaporizers?
(A) Compensation for changes in the specific heat of the anesthetic during vaporization
(B) Delivery of diluent gas at a constant temperature regardless of flow rate
(C) Increase of bypass flow when the vaporizer is cooled by high fresh gas flow
(D) Maintenance of constant anesthetic vapor output over a range of vaporizer temperatures
(E) Maintenance of constant vapor concentrations at low flow rates
A 50-year-old man with an 80 pack-year history of cigarette smoking has a forced expiratory volume in one second of 1.5 L and a forced vital capacity of 3.5 L. Which of the following statements concerning intraoperative anesthetic management is true?
(A) An I:E ratio of 1:1 will improve carbon dioxide removal more than an I:E ratio of 1:2.5
(B) Antagonism of neuromuscular block will most likely trigger acute bronchospasm
(C) Functional residual capacity will increase during an acute exacerbation of bronchospasm
(D) Induction with ketamine will increase airway resistance
A woman with chronic obstructive pulmonary disease is extubated and minimally responsive after isoflurane anesthesia. She is receiving oxygen 6 L/min through a face mask. Respirations are 10/min, PaO2 is 68 mmHg, PaCO2 is 54 mmHg, and pH is 7.28. The most likely cause of the respiratory acidemia is
(A) blunted sensitivity to low pH in the medullary respiratory center
(B) chronic carbon dioxide retention
(C) decreased lung volume from supine positioning
(D) depression of carotid body chemoreceptors by halothane
(E) suppression of hypoxic ventilatory drive by supplemental oxygen