The nurse admits an 81-year-old client with gastroenteritis. Admission vital signs are temperature 101 F (38.3 C), blood pressure 90/42 mm Hg, pulse 118/min, and respirations 32/min. Pulse oximetry shows 88%. The nurse suspects which of the following factors may be affecting accuracy of the pulse oximetry reading?
A)Dehydration
B)Elevated temperature
C)Hypotension
D)Tachypnea

Question

The nurse admits an 81-year-old client with gastroenteritis.  Admission vital signs are temperature 101 F (38.3 C), blood pressure 90/42 mm Hg, pulse 118/min, and respirations 32/min.  Pulse oximetry shows 88%.  The nurse suspects which of the following factors may be affecting accuracy of the pulse oximetry reading?
A)Dehydration
B)Elevated temperature
C)Hypotension
D)Tachypnea

Quizplus · Accepted Answer

11ecbb05_cb14_5267_b433_c9ed6fc50202_MD0009_00 A pulse oximeter is a noninvasive device that estimates the arterial blood saturation (SaO₂) by using a sensor attached to the adult client's finger, toe, earlobe, nose, or forehead. The sensor (reusable clip or disposable adhesive) contains both light-emitting and light-sensing components and measures the amount of light absorbed by hemoglobin in the arterial blood. Because the sensor estimates the value at a peripheral site, the oximeter reports the value as SpO₂. The sensor relies on adequate tissue perfusion, so low blood flow or decreased perfusion can decrease SpO₂ readings. Conditions associated with low blood flow or decreased perfusion states include cardiac dysrhythmias, heart failure, peripheral vascular disease, edema, hypotension, hypovolemic shock, and vasoconstriction (eg, hypothermia, smoking, drugs). Other factors affecting accuracy of the reading include improper positioning or fit of the sensor, excessive movement, smoke inhalation, and carbon monoxide poisoning. (Option A) Although dehydration can be associated with conditions that could cause decreased pulse oximetry readings, it is not an independent factor. (Option B) Elevated temperature is not a factor that could cause an inaccurately low pulse oximeter reading. (Option D) Although tachypnea can be associated with conditions that could cause decreased pulse oximetry readings, it is not an independent factor. Educational objective: Because the pulse oximeter sensor relies on adequate tissue perfusion, any condition associated with low blood flow or low perfusion states can decrease the reading. Pulse oximetry is also inaccurate in clients with carbon monoxide poisoning.

The Nurse Admits an 81-Year-Old Client with Gastroenteritis