ZOLL Thermogard XP IVTM Physician Manual - Manual (Page 24)

ZOLL IVTM™ System Physicians' Manual
600248-001 Rev 3 23
result endovascular methods of cooling allow the removal of heat at rates greater
than can be achieved with surface cooling for the same driving ΔT (i.e. difference in
temperature) between the core of the patient and the cooling source.
Gal and Cundrle [39] showed similar effects in their study of mild hypothermia in
patients scheduled for neurosurgical procedures. Using “back and front” cooling
blankets they reported that “the patients were cooled at a rate of 1.1+/-0.3 degrees
C/h and rewarmed at a rate of 0.9+/-0.4 degrees C/h.”. They reported no
complications attributed to the cooling in 20 elective patients.
Inoue et al [40] reported on active conventional cooling and rewarming rates
comparing device alone with device plus amrinone. Amrinone is an inotrope that
causes, amongst other things, decreased peripheral resistance i.e. it will reduce the
thermal insulation offered by the skin by reducing peripheral vasoconstriction.
Cooling rates were 0.96 vs 1.36ºC/h and rewarming rates were 1.02 v 0.73ºC/h for
the control v the Amrinone group respectively. The cooling device int his case was a
blanket system.
The above short literature review summarizes current expectations as to cooling and
rewarming rates in the context of neurosurgery.
Rewarming
Hypothermia after neurosurgery is of concern and occurs for reasons similar to those
described for cardiac surgery with the added problem of not having the efficient
warming provided by the cardiac bypass pump [41]. Shivering is associated with an
undesirable increase in left ventricular systolic work index and oxygen consumption
index in post-operative neurosurgical patients. Endovascular heat exchange
catheters offer controlled rewarming and help to ensure post-operative
normothermia.
Catheter Selection
The IVTM System and the various IVTM catheters offer a convenient alternative,
allowing fine and automatic control of the core temperature that can be maintained
until biological temperature-control mechanisms are fully reestablished. In this
application , the IVTM System can be used with four catheters of similar concept but
varying size.
The Icy catheter is suitable for femoral vein placement without a sheath for up to 4
days. It has a 8.5 Fr shaft. The Icy catheter has been CE marked and has proved
safe in clinical use .
The Quattro catheter is suitable for femoral vein placement without a sheath for up to
4 days. It has a shaft size of 9.3 Fr.
The Solex catheter is suitable for jugular vein placement without a sheath for up to 48
hours. It has a shaft size of 9.3 Fr.
Publications on the clinical use of IVTM Catheters include abstracts and peer
reviewed article[19][12][23].
For all IVTM catheters, please refer to the “Instructions for Use” for the complete list
of contra-indications, warning and instructions for a particular catheter. The section
below provides a guide to physicians to assist in catheter selection.