Monitor cardiorespiratory status, continuous pulse

oximetry. Determine blood gases as often as indicated

by pre-existing clinical condition and stability.

11. Draw blood for diagnostic studies.

12. Usual rate of removal and replacement of blood during

the ET is 5 mL/kg over a 2- to 4-minute cycle.

13. If infant is hypovolemic or has low CVP, start exchange

with transfusion of aliquot into catheter. If infant is

hypervolemic or has high CVP, start by withdrawing

precalculated aliquot.

14. Remeasure CVP if indicated. Expect rise as plasma

oncotic pressure increases, if CVP low at start.

15. Ensure that the stages of drawing and infusing blood

from and into the infant are done slowly, taking at

least a minute each to avoid fluctuations in blood

pressure. Rapid fluctuations in arterial pressure in the

push–pull technique may be accompanied by

changes in intracranial pressure (28). Rapid withdrawal from the umbilical vein induces a negative

pressure that may be transmitted to the mesenteric

veins and contribute to the high incidence of ischemic

bowel complications.

16. Gently agitate the blood bag every 10 to 15 minutes to

prevent red cell sedimentation, which may lead to

exchange with relatively anemic blood toward the end

of the exchange.

17. Consider giving calcium supplement.

a. When hypocalcemia is documented

Fig. 44.3. Special four-way stopcock. A: Male adapter to infant

line. B: Female adapter to waste container. C: Attachment to

blood tubing. D: “Off” position (180 degrees from adapter to waste

container), allowing injection through rubber-stoppered port

“below” syringe. The stopcock is used in clockwise rotation when

correctly assembled.

A B

Waste blood

bag connection

UVC

from

blood

warmer

Fig. 44.4. A, B: ET using special four-way stopcock.