Oximeters need a flow of blood through the finger to function. Some oximeters give an indication of the blood flow detected. In the oximeter shown in Fig 1 there is a scale which is an indication of the blood flow. Sometimes these have numbers on them.

Question: Why might this scale be important during anaesthesia?

Answer

Fig 1  

Oximeters need a flow of blood through the finger to function. Some oximeters give an indication of the blood flow detected. In the oximeter shown in Fig 1 there is a scale which is an indication of the blood flow. Sometimes these have numbers on them.

Question: Why might this scale be important during anaesthesia?

Answer: Low perfusion. Peripheral vasoconstriction will result in low perfusion This is commonly due to:

  • Cold
  • Hypovolaemia

Note the fast pulse rate and low perfusion alarm in Fig 3 compared with Fig 2.