| Title | Thermoregulatory defense mechanisms. | | Author(s) | Sessler DI | | Institution | Department of Outcomes Research, The Cleveland Clinic, Cleveland, OH, USA. ds@or.org | | Source | Crit Care Med 2009 Jul; 37(7 Suppl):S203-10. | | MeSH | Age Factors
Analgesics
Anesthetics, General
Autonomic Nervous System
Body Temperature Regulation
Brain Ischemia
Circadian Rhythm
Critical Care
Drug Therapy, Combination
Evidence-Based Medicine
Fever
Humans
Hypothermia, Induced
Myocardial Ischemia
Sensory Thresholds
Shivering
Thermodynamics
Transient Receptor Potential Channels
Treatment Outcome
Vasoconstriction
| | Abstract | Core body temperature is normally tightly regulated by an effective thermoregulatory system. Thermoregulatory control is sometimes impaired by serious illness, but more typically remains intact. The primary autonomic defenses against heat are sweating and active precapillary vasodilation; the primary autonomic defenses against cold are arteriovenous shunt vasoconstriction and shivering. The core temperature triggering each response defines its activation threshold. Temperatures between the sweating and vasoconstriction thresholds define the inter-threshold range. The shivering threshold is usually a full 1 degrees C below the vasoconstriction threshold and is therefore a "last resort" response. Both vasoconstriction and shivering are associated with autonomic and hemodynamic activation; and each response is effective, thus impeding induction of therapeutic hypothermia. It is thus helpful to accompany core cooling with drugs that pharmacologically induce a degree of thermal tolerance. No perfect drug or drug combination has been identified. Anesthetics, for example, induce considerable tolerance, but are rarely suitable. Meperidine-especially in combination with buspirone-is especially effective while provoking only modest toxicity. The combination of buspirone and dexmedetomidine is comparably effective while avoiding the respiratory depression association with opioid administration. | | Language | eng | | Pub Type(s) | Journal Article
Review
| | PubMed ID | 19535948 |
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