Arterial pressure in the radial artery is 155/70 mmHg measured by a correctly calibrated catheter-transducer system. At the same time, aortic pressure is 140/75 mmHg using a high-fidelity catheter tip transducer. The most likely cause of this discrepancy is
(A) a large amount of air in the dome of the radial artery transducer
(B) coarctation of the aorta
(c) peripheral vascular constriction produced by sympathetic stimulation
(D) physiologic amplification of the waveform from the aorta to the radial artery
(E) too high a frequency response in the catheter-transducer system
During an otherwise uneventful nitrous oxide-sevoflurane anesthetic in a spontaneously breathing patient, 85% nitrous oxide is accidently administered, resulting in a PO2 of 48 mmHg. Which of the following would be expected?
A patient with lumbar disk disease requires lumbar epidural injection of a corticosteroid for control of low back pain. Which of the following statements concerning this treatment is true?
(A) Maximum effect occurs one hour after injection
(B) Maximum effect occurs when drug concentration peaks in cerebrospinal fluid
(C) Maximum effect occurs during the acute phase of the disease
(D) The beneficial effect results primarily from sympathetic neurolysis
(E) It is contraindicated if the patient has had prior surgical procedures on the lumbar disks
C
An unvaccinated health care worker is stuck by a needle contaminated with blood from an HBsAg-positive patient. Which of the following statements concerning this situation is true?
(A) The risk for development of HIV infection is greater than the risk for development of hepatitis
(B) Hepatitis immune globulin is indicated if the health care worker is HBcAg positive
(C) Hepatitis B vaccine should be administered
(D) Hepatitis immune globulin will protect equally against hepatitis B and hepatitis C (non-A, non-B)
(E) Hepatitis B vaccine carries a risk for transmission of HIV
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?