Fig. 10.7. A: Principle of cutaneous PO2 measurement by

heated oxygen sensor. B: Temperature profile of cutaneous tissue.

C: Cross section of cutaneous oxygen sensor. (Courtesy of Kontron

Medical Instruments, Ergolding, Germany.)

Chapter 10 ■ Continuous Blood Gas Monitoring 71

2. Perform routine electrode maintenance, if there is any

question as to the status of the electrode.

a. Remove the membrane, rinse the electrode with deionized water, and dry with a soft lint-free tissue or gauze.

b. Clean the electrode using the solution provided in

the cleaning kit; abrasive compounds or materials

should never be used (they will permanently damage the electrode).

c. Rinse the electrode with deionized water, and dry

with lint-free tissue.

d. Apply the electrolyte solution.

e. Place a new membrane on the electrode. Avoid finger contact, and always handle the membrane

inside its protective package or with plastic tweezers.

3. Perform two-point gas calibration using the device-specific apparatus, as per manufacturer’s instruction.

4. Use an alcohol pad to clean and degrease the skin site

where the sensor is to be placed.

5. Apply double-sided adhesive ring to the sensor.

6. Apply one drop of contact solution to the skin site.

7. Peel the protective backing from the adhesive ring,

place the sensor on the skin over the contact solution,

and press the sensor to the skin.

a. For best results, place the sensor on a location with

good blood flow.

(1) Appropriate sites include the lateral abdomen,

anterior or lateral chest, volar aspect of the forearm, inner upper arm, inner thigh, or posterior

chest (Fig. 10.9) (21)

(2) Although large differences between pre- and

postductal PaO2 values are uncommon in premature infants with hyaline membrane disease,

preductal location of the electrode is optimal for

prevention of hyperoxemia (22)

b. Choose a site devoid of hair.

c. Avoid bony prominences.

d. Avoid areas with large surface blood vessels (Fig. 10.9).

8. Secure the sensor cable to prevent tugging of the electrode when the cable is manipulated.

9. Allow 15 to 20 minutes for site equilibration before taking readings.

10. Note the time at which the sensor was placed on the

skin, so that the site can be changed after a 4-hour

period (maximum site time). When changing the sensor site

a. Use an alcohol pad to help loosen the adhesive and

peel gently from the skin.

b. Inspect the skin site for signs of sensitivity to heat or to

the adhesive. In the event of skin irritation, either lower

the sensor temperature or change the site more frequently; mild erythema after sensor removal is typical.

Fig. 10.9. Cutaneous PO2/PCO2 sensor applied to the back.

Fig. 10.8. Combined transcutaneous

PO2/PCO2 and SpO2 monitor. (Courtesy of

Radiometer.)