Question

During a cross-country, arctic snowmobile extravaganza, Itsa Cold was exposed to 'the elements." Ms. Cold is a nonsmoker. Her hemoglobin level is 14 Gm%. She presents complaining of dizziness after her snowmobile collided with a large igloo. Her blood pressure is 92/52 mm Hg and her heart rate is 132. You place a pulse oximeter on her left index finger. The arterial oxyhemoglobin saturation, on room air, is 93%. Which of the following statements is most likely true?

a. Ms. Cold is hypoxic.
b. Ms. Cold has very dark (opaque) finger nail polish on her fingers.
c. Ms. Cold is hypocapnic
d. Ms. Cold takes propranolol daily.
e. Ms. Cold has an arterial pO2 above 60.

Answer 1

Ms. Cold likely has an arterial pO2 above 60 mm Hg, as her oxyhemoglobin saturation on room air is 93%, which, while slightly below normal, is not indicative of severe hypoxemia or hypoxia. Her low blood pressure and elevated heart rate could relate to other causes, but based on her pulse oximetry reading, severe hypoxemia is not the immediate concern.

Step-by-step explanation:

Given the patient's arterial oxyhemoglobin saturation of 93% on room air, it is most likely that the direct answer to the question is that Ms. Cold has an arterial pO2 above 60 mm Hg. A pulse oximeter reading between 95-100% is considered normal, and her reading, while slightly lower, is not indicative of severe hypoxemia, which suggests that her arterial oxygen pressure (pO2) is still above the threshold for concerning hypoxemia, typically around 60 mm Hg.

Pulse oximetry is a non-invasive method that allows for the monitoring of the oxygenation of a patient's hemoglobin. A sensor placed on a thin part of the patient's body, such as a finger, uses light wavelengths to measure oxygen saturation. Hemoglobin saturation with oxygen determines how much light is absorbed by the blood; therefore, using this method can provide an immediate reading of a patient's oxygen levels. Despite concerns indicated by her symptoms, such as low blood pressure and tachycardia, the pulse oximetry measurement suggests that Ms. Cold's oxygen level is likely stable, and that she is not hypoxic.

Other options, like being hypoxic or having opaque fingernail polish, are less likely based on the information provided. Hypoxia is generally accompanied by a much lower saturation level than what is observed with Ms. Cold. Nail polish, especially if it is dark or opaque, can interfere with the pulse oximeter's function, causing an inaccurately low reading, but this is not suggested in the scenario. Ms. Cold being hypocapnic or using propranolol are unrelated to the measurement of her arterial oxyhemoglobin saturation, as they would affect her physiological response rather than the reading itself.