A healthy, 18-year-old, 65-kg woman undergoing diagnostic laparoscopy is being monitored with a properly functioning and calibrated capnograph. The end-tidal carbon dioxide concentration is 6%, and the inspired carbon dioxide concentration is 1%. This may be caused by each of the following EXCEPT
(A) malfunction of the expiratory valve in a circle system
(B) low gas inflow with a Bain circuit
(C) exhausted soda lime within a circle system
(D) absorption of carbon dioxide from carbon dioxide laparoscopy
A 31-year-old man received an uneventful epidural anesthetic for arthroscopy of the knee and meniscectomy. Twenty-four hours later he still has painless flaccid paralysis in both legs. This clinical presentation is most consistent with
An 87-kg 64-year-old woman in good general health is undergoing a right knee arthroplasty while in the supine position with general anesthesia consisting of enflurane 2% and nitrous oxide 50% in oxygen. She is breathing spontaneously through a 7-mm endotracheal tube. During the first 30 minutes of the procedure, the arterial oxygen saturation measured by pulse oximetry decreases from 98% to 92%. The most likely cause of the desaturation is
(A) decreased functional residual capacity
(B) diffusion hypoxia
(C) hypercarbia
(D) increased airway resistance produced by the endotracheal tube
(E) inhibition of hypoxic pulmonary vasoconstriction
A
An otherwise healthy 42-year-old woman is referred for management of pain associated with adenocarcinoma of the breast and metastasis to the anterior body of L3. She perceives the pain as moderate and currently takes no pain medication. Her oncologist estimates her life expectancy to be 18 months. The most appropriate initial management is
(A) a benzodiazepine as needed and at bedtime
(B) an oxycodone preparation as needed and a tricyclic antidepressant at bedtime
(C) intravenous patient-controlled analgesia
(D) morphine infusion via an implanted epidural catheter
A 2.2-kg, 6-hour-old neonate is to undergo gastrostomy followed by repair of a tracheoesophageal fistula. During induction with halothane, air, and oxygen, the abdomen becomes distended. Appropriate management is to
(A) intubate and assist spontaneous ventilation
(B) intubate and control ventilation
(C) insert an orogastric tube
(D) allow the patient to breathe spontaneously by mask until gastrostomy