Cold pressor test
Encyclopedia
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
. Its response is clinically indicative concerning vascular
response and pulse
excitability.
Other measures can also be obtained from the cold pressor such as pain threshold and pain tolerance
. 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 his/her 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.
. The result is an elevated pulse pressure(normal is 70mm Hg), due to catecholamine release. This increased pressure fills the ventricle to a greater extent, but stroke volume decreases for by an increase in afterload
.
Ice water
- Music :* Ice Water , a song from Cat Power's second album Myra Lee* Ice Water , an album by guitarist Leo Kottke* Ice Water Inc., a music group affiliated with the Wu Tang Clan- Other uses :* Ice Water , Thoroughbred racehorse...
container, usually for one minute, and measuring changes in blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
and heart rate
Heart rate
Heart rate is the number of heartbeats per unit of time, typically expressed as beats per minute . Heart rate can vary as the body's need to absorb oxygen and excrete carbon dioxide changes, such as during exercise or sleep....
. Its response is clinically indicative concerning vascular
Vascular
Vascular in zoology and medicine means "related to blood vessels", which are part of the circulatory system. An organ or tissue that is vascularized is heavily endowed with blood vessels and thus richly supplied with blood....
response and pulse
Pulse
In medicine, one's pulse represents the tactile arterial palpation of the heartbeat by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed against a bone, such as at the neck , at the wrist , behind the knee , on the inside of the elbow , and near the...
excitability.
Other measures can also be obtained from the cold pressor such as pain threshold and pain tolerance
Pain tolerance
Pain tolerance is the maximum level of pain that a person is able to tolerate. Pain tolerance is distinct from pain threshold .-Factors affecting pain tolerance:...
. This is done by requiring a participant to place their hand in the cold pressor for as long as they can. Once pain
Pain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
is present, they let the researcher know. Once the pain is unbearable, the participant removes his/her 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
Confounding
In statistics, a confounding variable is an extraneous variable in a statistical model that correlates with both the dependent variable and the independent variable...
of baroreflex
Baroreflex
The baroreflex or baroreceptor reflex is one of the body's homeostatic mechanisms for maintaining blood pressure. It provides a negative feedback loop in which an elevated blood pressure reflexively causes heart rate to decrease therefore causing blood pressure to decrease; likewise, decreased...
activation.
Physiology
Sensory afferents trigger a systemic sympathetic activation leading to marked vasoconstrictionVasoconstriction
Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries, small arterioles and veins. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in...
. The result is an elevated pulse pressure(normal is 70mm Hg), due to catecholamine release. This increased pressure fills the ventricle to a greater extent, but stroke volume decreases for by an increase in afterload
Afterload
Afterload is the tension or stress developed in the wall of the left ventricle during ejection. Following Laplace's law, the tension upon the muscle fibers in the heart wall is the product of the pressure within the ventricle, multiplied by the volume within the ventricle, divided by the wall...
.