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Skin blood flow and sweating in health and disease

Skin blood flow and sweating in health and disease. Craig Crandall, Ph.D. Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, and Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas. Semenza et al. Am J Prev Med 1999.

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Skin blood flow and sweating in health and disease

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  1. Skin blood flow and sweating in health and disease Craig Crandall, Ph.D. Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, and Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas.

  2. Semenza et al. Am J Prev Med 1999

  3. Semenza et al. N Engl J Med. 1996

  4. Heat stress Cutaneous vasodilation Decreases systemic vascular resistance Increases cardiac output Maintenance of blood pressure Blood pressure = TPR * CO Heart Failure Of the “excess” death identified in the cohort from the 1995 Chicago heat wave, 39% had a prior “heart condition” Semenza et al. N Engl J Med. 1996

  5. Heart Failure (N=14) NYHA Class II and III Controls (N=14) Normothermia Heat stress E.F. (%) 30  2 - Age (yrs) 51  4 - MAP (mmHg) 90  3 85 4 HR (bpm) 70  4 87  5* Tsk ( C) 34.1  0.1 38.0  0.2* Normothermia Heat stress 64  1 - 51  4 - 87  2 82 2 58  4 80  4* 34.1  0.1 38.0  0.2* Cui, Arbab-Zadah, Prasad, Durand, Levine, Crandall. Circulation (2005)

  6. Cui, Arbab-Zadah, Prasad, Durand, Levine, Crandall Circulation (2005)

  7. Vasodilation Internal Temp Central Nervous System Skin Temp Vasoconstriction Cutaneous Vasculature Sudomotor Congestive Heart Failure Sweat Gland

  8. Cui, Arbab-Zadah, Prasad, Durand, Levine, Crandall Circulation (in press)

  9. Summary Impaired thermoregulation in subjects with CHF is primarily due to reduced cutaneous vasodilation since sweating responses are normal during the heat stress. Possible mechanisms ???

  10. “We had a new recruit die here at ----------- last week due to a heat-induced arrhythmia.  His core temp was 106 F.  He died standing in the chow line- and had done very minimal exertion that day (2 mi walk several hours earlier).  The guy had burn injuries at age 11- he had skin grafts covering 30% of his trunk- to include one axilla.  Our Army medical fitness reg make no mention of skin grafting/burns as a disqualifier- and we are seeking additional knowledge to see if we need to change the regulation.   Since so many of our soldiers have recently acquired burn injuries and are subjected to tremendous thermal stress we think that this is a very important question.”

  11. Whole-body heat stress

  12. Grafted Skin * Normal Skin * * Normotherm. Heat Stress Graft Graft Sweat Rate (mg/cm2/min) 1000 * 500 0

  13. Co-transmitters ACh Endothelium NO VIP, etc. PGs EDHF Cutaneous Vasculature Sympathetic Cholinergic Nerve ACh Administration SNP Administration

  14. Laser Doppler Probe Sweat Capsule Dry Nitrogen Gas Humidity Sensor Acetylcholine (ACh) (10-7 M to 1 M) Skin 10 mm

  15. *  EC50 = -3.34 ± 0.46 * 2.00 ▼Graft  EC50 = -2.61 ± 0.44 † 1.75 * 1.50 * 1.25 1.00 DCVC from Baseline (au/mmHg) 0.75 0.50 0.25 0.00 -0.25 -7 -6 -5 -4 -3 -2 -1 log [ACh] *P<0.05 † P<0.01 Cutaneous vascular conductance (CVC) response to exogenous acetylcholine (ACh)  Control

  16.  EC50 = -3.94 ± 0.45 * ▼ Graft  EC50 = -4.43 ± 1.08 *P<0.05 Cutaneous vascular conductance (CVC) response to exogenous sodium nitroprusside (SNP) 2.25  Control 2.00 1.75 1.50 1.25 CVC from Baseline (au/mmHg) 1.00 0.75 0.50 0.25 0.00 -0.25 -8 -7 -6 -5 -4 -3 -2 log [SNP]

  17. ▼ Graft * * *P<0.05 Sweat rate (SR) response to exogenous acetylcholine (ACh) administration 1.0  Control 0.8 0.6 DSR from Baseline (mg/cm2/min) 0.4 0.2 0.0 -0.2 -7 -6 -5 -4 -3 -2 -1 log [ACh]

  18. Summary of Findings • Cutaneous vasodilation to whole-body heating is absent in grafted skin • ACh mediated vasodilation (endothelial dependent) is inhibited in grafted skin • Nitric oxide mediated vasodilation (endothelial independent) is attenuated at the highest dose in grafted skin • No sweating suggests abnormal or absence of functional sweat glands

  19. Implications • Juvenile (i.e. 6-9 months post-surgery) split thickness skin grafts have an attenuated capability of contributing to thermoregulation • Increased risk of heat related injury • It is unknown whether there is a restoration of cutaneous vasodilation and sweat function with graft maturity?

  20. 31 year old man with a 10 year history of drug abuse was found disoriented and combative. Blood pressure: 115/76 mmHg; heart rate: 197 bpm; respiratory rate: 72/min; temperature 107.2 F (41.8 C). Urine specimen tested positive for cocaine metabolite and negative for ethanol and other central nervous stimulants. Patient died. Human Pathology, 22:1141-1145, 1991. 38 year old known cocaine user was transported to emergency room by the police after acting bizarrely and barking like a dog. The patient was agitated, diaphoretic, incoherent, and unresponsive to pain. Urine specimen tested positive for cocaine and cocaine metabolites and nicotine. Blood pressure: 120/69 mmHg; heart rate: 150 bpm; respiration: 40/min; temperature 41.1 C (106 F). Patient died seven days after admission. Western J. Med. 150:210-212, 1989. 14 patients with rhabdomyolysis after cocaine use had an average temperature of 103.7 F (range 99 – 106  F). The average temperature for the 5 patients that died was 105.4 F (40.8 C). Acta Neurol. Scand. 92: 161-165, 1995.

  21. Pre-heat stress (~30 min post-drug) (2 mg/kg) (2 mg/kg) Mean ±(SEM) Crandall, Vongpatanasin, Victor Ann Int Med 2002

  22. Crandall, Vongpatanasin, Victor Ann Int Med 2002

  23. 0 . 9 8 0 Lidocaine Cocaine Cocaine 6 0 Lidocaine 0 . 6 Sweat Rate (mg/cm2/min) Cutaneous Vascular Conductance 0 4 0 2 0 . 3 0 3 7 . 0 3 7 . 2 3 7 . 4 3 7 . 6 3 7 . 8 Esophageal Temperature 0 . 0 Esophageal Temperature 3 7 . 0 3 7 . 2 3 7 . 4 3 7 . 6 3 7 . 8 Crandall, Vongpatanasin, Victor Ann Int Med 2002

  24. 4.0 Neutral 4.5 5.0 Warm 5.5 6.0 Hot 6.5 7.0 Very hot 7.5 8.0 Unbearably hot Toner, Drolet, Pandolf Percept Motor Skills 1986

  25. Crandall, Vongpatanasin, Victor Ann Int Med 2002

  26. Summary Intranasal cocaine significantly impairs thermoregulation as evidenced by a delay in the onset of cutaneous vasodilation and sweating. Moreover, cocaine impairs the perception of heating such that the individual does not recognize they are as hot when compared to the placebo trial.

  27. Contributors Scott Davis, Ph.D. David Keller, Ph.D. David Low, Ph.D. Marilee Brown, R.N. Rebecca MacDougal, M.D. Obiora Chukwumah, MBBS John Hunt, M.D. Gary Purdue, M.D. Karen Kowalske, M.D.

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