The cold pressor test is a
cardiovascular test performed by immersing the hand into an ice water container, usually for one minute, and measuring changes in
blood pressure and
heart rate. These changes relate to
vascular response and
pulse excitability. Some research suggests that the outcome of the cold pressor test can help to predict hypertension in patients; however other studies have failed to confirm this.[1][2][3][4]
Other measures can also be obtained from the cold pressor such as
pain threshold and
pain tolerance.[5][6][7] This is done by requiring a participant to place their hand in the cold pressor for as long as they can. Once
pain is present, they let the researcher know. Once the pain is unbearable, the participant removes their hand. This provides a measure of threshold (first feeling pain) and tolerance (total time minus threshold). This method is the most frequently used application of the cold pressor task. Comparable in terms of pain elicitation is the
hot water immersion test, the equivalent to the cold pressor using hot water. The hot water immersion test (HIT) is equally capable of triggering a pain response without the
confounding of
baroreflex activation.[8]
Physiology
Sensory afferent nerves trigger a systemic sympathetic activation leading to marked
vasoconstriction. The result is an elevated
pulse pressure (normal is 40mm Hg), due to
catecholamine release. This increased pressure fills the ventricle to a greater extent, but
stroke volume decreases due to an increase in
afterload.[citation needed]
^Harlan WR, Osborne RK, Graybiel A (May 1964). "Prognostic value of the cold pressor test and the basal blood pressure: Based on an eighteen-year follow-up study". The American Journal of Cardiology. 13 (5): 683–687.
doi:
10.1016/0002-9149(64)90205-X.
PMID14152011.
Lafleche AB, Pannier BM, Laloux B, Safar ME (August 1998). "Arterial response during cold pressor test in borderline hypertension". The American Journal of Physiology. 275 (2): H409–15.
doi:
10.1152/ajpheart.1998.275.2.H409.
PMID9683427.