Syringe A contains 100 ml of normal blood with a PO2 of 2 mmHg, and syringe B contains 100 ml of normal blood with a PO2 of 98 mmHg. The contents of the two syringes are mixed anaerobicaily to equilibrium. The PO2 of the resultant mixture Is
A 70-year-old man sustains injuries to both carotid bodies during bilateral carotid endarterectomies performed four days apart. Two hours after the second procedure, the patient is breathing room air in the PACU. Which of the following sets (pH, pCO2, pO2) of arterial blood gas values is LEAST likely?
(A) 7.3 50 58
(B) 7.3 50 86
(C) 7.4 40 86
(D) 7.4 42 58
(E) 7.5 32 58
E
During nitrous oxide anesthesia, which of the following expands most rapidly?
(A) Air bubble in the blood
(B) Air in the intestine
(C) Endotracheal tube cuff
(D) Pneumothorax
(E) Sulfahexafluoride bubble in the vitreal cavity
A patient is undergoing cholecystectomy with enflurane, nitrous oxide, fentanyl, and oxygen. He takes theophylline and cromolyn sodium for bronchial asthma. During skin incision he has bilateral wheezing; peak inspiratory pressure is 50 cmHzO, and the ECG shows occasional premature ventricular contractions. The most appropriate management is to
(A) switch from enflurane to isoflurane
(B) administer lidocaine intravenously
(C) administer methylprednisolone intravenously
(D) administer nebulized cromolyn sodium
(E) administer nebulized metaproterenol
E
Which of the following statements concerning carbon monoxide poisoning is true?
(A) Diagnosis is excluded if the PaO2 is greater than 300 mmHg while breathing 100% oxygen
(B) Increased inspired oxygen concentration accelerates displacement of carbon monoxide from hemoglobin
(C) Methylene blue decreases binding of carbon monoxide to hemoglobin