Q: Pulse-oximetry reading (finger probe) lags behind the central arterial circulation?
Answer: True (A)
Although sound very simple and obvious but this is a critical point in intensive care unit's patients where other clinical signs of deterioration precede before desaturation. This lagging of pulse-ox desaturation may put an unexperienced house-staff under false sense of comfort and golden moment of intervention may get lost.
1. Weingart SD, Levitan RM. Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med 2012; 59:165.
2. Ding ZN, Shibata K, Yamamoto K, et al. Decreased circulation time in the upper limb reduces the lag time of the finger pulse oximeter response. Can J Anaesth 1992; 39:87.