During acute normovolemic hemodilution in an adult, which of the following compensatory mechanisms is most important in maintaining tissue oxygenation?
A 25-year-old woman is undergoing emergency appendectomy at 36 weeks' gestation. Following subarachnoid injection of hyperbaric bupivacaine and placement in the supine position, the patient has nausea; heart rate is 105 bpm and blood pressure is 90/60 mmHg. Which of the following is the most appropriate management?
(A) Displacement of the uterus to the left
(B) Immediate tracheal intubation
(C) Intramuscular administration of ephedrine
(D) Placement of the operating table in the reverse Trendelenburg position
A 24-year-old man who sustained multiple rib fractures in a motor vehicle accident has air leaks through bilateral chest tubes. Which of the following is most likely following initiation of high-frequency jet ventilation?
(A) Airway pressure will be measured most reliably at the proximal (external) end of the endotracheal tube
(B) Atelectatic areas of the lungs will re-expand
(C) Changes in end-tidal carbon dioxide tension measured at the tip of the endotracheal tube will match changes in PaCOz
(D) Hypercarbia will develop
(E) The air leaks will be proportional to peak airway pressure
E
During anesthesia using the Bain circuit
(A) PaCO2 is independent of minute volume if fresh gas flow is greater than 17 ml/kg
(B) PaCO2 is independent of fresh gas flow if minute volume is greater than 100 ml/kg
(C) PaCO2 may be normal in the presence of rebreathing
(D) carbon dioxide removal is more efficient during spontaneous ventilation than during controlled ventilation
(E) less body heat is lost than with a circle system
A waste-gas scavenger has an active disposal system. Which of the following safety features is necessary to prevent removal of excess gas from the breathing circuit?