An arterial blood sample is obtained from a patient undergoing hypothermic cardiopulmonary bypass at 28 C. Analysis at 37 C shows a pH of 7.40 and PaCO2 of 40 mmHg. Which of the following values are most likely if the analysis is corrected to 28 C?
A 32-year-old woman is anesthetized for suboccipital craniotomy. During positioning, the capnograph shows an abrupt decrease in the slope of the expiratory upstroke. Which of the following is the most likely cause?
During laser excision of vocal cord polyps in a 5-year-old boy, dark smoke suddenly appears in the surgical field. The trachea is intubated and anesthesia is being maintained with halothane, nitrous oxide, and oxygen. The most appropriate initial step is to
A 5-year-old boy is to undergo microlaryngeal carbon dioxide laser vaporization of laryngotracheal papillomas under halothane administered through a small polyvinylchloride (PVC) endotracheal tube. The diluent gas mixture LEAST likely to support laser combustion of the PVC tube is
A 46-year-old patient who abuses intravenous drugs develops acute aortic valvular insufficiency from bacterial endocarditis. Which of the following statements concerning pressures measured through a pulmonary artery catheter is true?
(A) Pulmonary artery occlusion pressure will underestimate left ventricular end-diastolic pressure
A 75-year-old man with a left bundle branch block is undergoing placement of a pulmonary artery catheter through the right internal jugular vein. He becomes pale and his heart rate decreases to 40 bpm when the catheter tip enters the right ventricle. The most likely cause is
During induction of general anesthesia in a patient with a supraglottic tumor, both intubation and subsequent ventilation via a face mask are impossible. A cricothyroidotomy is performed with a 16-gauge intravenous catheter. Which of the following statements is true?
(A) Application of pressures greater than 35 cmH2O to the catheter will increase the risk for pulmonary barotrauma
(B) PaC02 can be maintained at a normal level using a standard circle system attached to the catheter
(C) PaO2 greater than 100 mmHg can be maintained indefinitely using transtracheal jet ventilation with pure oxygen through the catheter
(D) Emergency surgical tracheostomy would have improved the likelihood of survival
(E) The presence of this tumor contraindicates jet ventilation via cricothyroidotomy
A pulmonary artery catheter is placed in an awake patient breathing room air. Typical right ventricular and pulmonary artery pressure tracings are obtained. With the catheter balloon inflated, blood drawn from the distal port has a PaO2 of 100 mmHg, while a simultaneous radial artery sample has a PaO2 of 90 mmHg. These data indicate that the
A multi-orifices right heart catheter is being positioned by EKG control prior to sitting craniotomy. The EKG tracing is obtained between the distal tip of the catheter and the right arm lead. The most appropriate next step is to
A child undergoing general anesthesia is breathing spontaneously using the Jackson-Rees modification of the Ayres T-piece. Respiratory rate is 20/min and tidal volume is 75 ml. What is the minimum fresh gas flow required to prevent rebreathing?
A neurologically intact 48-year-old woman is scheduled for removal of a parietal lobe arteriovenous malformation. The relative risk for complete resection is to be determined by a test occlusion of the feeding artery. Which of the following intraoperative monitoring techniques is most appropriate for this test?
(A) Brain stem auditory evoked potentials
(B) Cerebral blood flow using radioactive xenon
(D) Evoked potentials elicited by stimulating the posterior tibial nerve
A 2-year-old child has cardiac arrest during an inguinal herniorrhaphy under general anesthesia administered during a Jackson-Rees system. The graph shows end-tidal PCO2 monitored from the tip of the endotracheal tube during cardiopulmonary resuscitation; minute ventilation is unchanged. Which of the following is the most likely cause of the change beginning at the arrow?
An otherwise healthy 16-year-old girl is undergoing posterior spinal fusion for thoracolumbar scoliosis. During the procedure, the most likely cause of a marked decrease in the amplitude of the somatosensory evoked potentials after stimulation of the posterior tibial nerve is
(A) administration of fentanyl 30 jag /kg for induction
(B) administration of isoflurane 1.3 MAC for maintenance
(C) administration of vecuronium 0.15 mg/kg
(D) a decrease in body temperature from 37 to 35°C