The purpose of the present study was to examine the effect of heat stimulation of cutaneous thermoreceptors on the volume and flow parameters of respiration.
Human Physiology, Vol. 29, No. 6, 2003, pp. 746–748. Translated from Fiziologiya Cheloveka, Vol. 29, No. 6, 2003, pp. 97–100. Original Russian Text Copyright © 2003 by Simonova, Kozyreva.
Changes in Spirometric Parameters upon Local Heating of Forearm or Hand Skin T. G. Simonova and T. V. Kozyreva Institute of Physiology, Siberian Division, Russian Academy of Medical Sciences, Novosibirsk, Russia Received February 12, 2001
Abstract—Local heating of the forearm or hand moderately decreases the respiratory volume parameters without changing bronchoconstriction. At the same time, a significant increase in the maximal expiratory flow (MEF50 and MEF75) indicates a limited enhancement of expiration upon local heating. In contrast, local cooling limits the maximum inspiration without affecting expiration.
The literature contains convincing data implicating peripheral thermoreceptors in regulation of respiration. Even short-term and slight cooling of the face, torso, forearm, or upper regions of the respiratory tract leads to significant changes in lung ventilation, oxygen consumption, respiratory rate, depth of respiration, and expiration duration [1–3]. Cold stimulation of thermoreceptors of the upper respiratory tract and the face is known to decrease lung ventilation, prolong the expiration phase, and decrease the hypercapnic rebreathing response [4–6]. In addition, inspiring cold air or facial cooling decreases bronchial patency in healthy subjects and can cause bronchospasm in asthmatic patients [7]. Our previous studies [8–11] showed that local cooling of the hand or forearm skin was associated with alterations in not only external respiration parameter respiratory (minute volume, vital capacity, respiratory rate, oxygen consumption, and the coefficient of oxygen utilization), but also spirometric parameters. The effect of local skin heating on spirometric parameters is less studied. It is only known that raising the temperature of different skin areas by 6–8°C produces no effect on bronchial patency [12]. The purpose of the present study was to examine the effect of heat stimulation of cutaneous thermoreceptors on the volume and flow parameters of respiration. METHODS Ten healthy 25- to 28-year-old men were examined. After 20 min of rest in a comfortable armchair at 22– 24°C, each subject performed two respiratory maneuvers, one for determining the vital capacity (VC) and the other for determining the forced VC (FVC). The first maneuver is an unforced but complete expiration via the mouth following a deep inspiration. The second maneuver is a quick and complete expiration after a full inspiration. Only the VC was measured during the first maneuver; the FVC, forced expiratory volume within the first second (FEV1), peak expiratory flow (PEF),
and MEF25–75 (the maximal expiratory flow (MEF) volume exhalation rates at 25, 50, and 75% of the expired FVC) were determined during the second maneuver. Automatic data processing included calculation of the Tiffeneau index and comparison of each spirometric parameter with its reference value, taking into account the age, height, and body weight of the subject. All spirometric parameters were recorded with a Master Lab instrument (Eager). Special studies showed that changes in the respiration parameters could be induced by thermal stimulation of a skin area larger than 4 × 4 cm2 [13]. Thermal stimulation was delivered via a 25-cm2 brass water-perfused thermode. The water temperature was maintained at 40–41°C with a thermostat. This temperature is known to be optimal for activation of skin thermoreceptors. Cutaneous thermal stimulation was delivered to the hand and the forearm in random order. The skin temperature under the thermode was continuously monitored using a thermistor. The rise of the temperature the mean initial level of 31.2 ± 0.4°C was 7–8°C. A respiratory response to cutaneous thermal stimulation is known to be elicited 30 s after its start and to persist for several minutes after the termination of stimulation [14]. The respiratory maneuvers were performed 30 s and 3 and 7 min after the beginning of stimulation and 3 and 7 min after its termination. Preliminary studies showed that the respiratory response developed within the first few minutes of heating and that the skin temperature returned to the initial level within 6–7 min of the recovery period. RESULTS AND DISCUSSION In all the subjects, the initial spirometric parameters were within the normal range (table). Local heating of the forearm skin decreased the VC, FVC, and FEV1 by 4–7% and the PEF by 8–12%. Their decrease was significant at all observation times, from 30 s of heating onward, until the skin temperature returned to its initial
0362-1197/03/2906-0746$25.00 © 2003 MAIK “Nauka /Interperiodica”
CHANGES IN SPIROMETRIC PARAMETERS UPON LOCAL HEATING Percentage of the initial level (a) 25
Percentage of the initial level (a) 25
*
15
15 *
5
–5 **
**
*
–15 **
**
*
*
**
15
*
** (b)
25
(b)
25
15 *
5
5 –5
*
5
–5 –15
747
*
–15
FVC VC
–5
*
*
PEF FEV1
–15
MEF25 MEF75 Tiffeneau MEF50 index test
*
* FVC
VC
PEF FEV1
MEF25 MEF75 Tiffeneau MEF50 index test
Fig. 1. Changes in spirometric parameters 7 min after the start of (a) forearm or (b) hand heating. Significant changes: *p < 0.05; **p < 0.01.
Fig. 2. Changes in spirometric parameters 7 min after the start of (a) forearm or (b) hand cooling. Significant changes: *p < 0.05; **p < 0.01.
value. Local forearm heating also increased the MEF50 (by 6–7%) and considerably increased the MEF75 (by 19–25%), which indicated acceleration of the forced expiration. Figure 1a presents the most pronounced changes in the spirometric parameters, observed 7 min after the start of forearm heating. Local heating of hand skin caused similar but significantly smaller changes in the spirometric parameters. The VC, FVC, and FEV1 started to decline at the beginning of heating, decreasing only slightly. The MEF75 increased by only 12–18% (compared to 19–25% in response to forearm heating; Fig. 1b). In contrast to the case of the forearm, all the parameters returned to their initial values after the termination of heating. Earlier, we showed [11] that local forearm cooling decreased the VC, FVC, FEV1, and PEF by 7–9, 3–4, 4–5, and 4–8%, respectively (Fig. 2a). A similar but milder response was elicited by hand cooling. The poorer response of the hands to thermal stimulation may be due to the fact that the forearms are usually less heavily exposed to thermal influences than are the hands.
Notably, the decrease in the VC, FVC, FEV1, and PEF induced by local heating or cooling of the forearm or hand skin probably is not associated with bronchoconstruction, because there was no decrease in the Tiffeneau index. Moreover, cutaneous cooling of these areas significantly increased this parameter (Fig. 2). The FEV1 is known to be an integrative characteristic of bronchial patency and of the effort of respiratory muscles during forced exhalation. Since the bronchial patency did not decrease, the decrease in the FEV1 could be due to a reduction in respiratory muscle effort during respiratory maneuvers. This is in line with data reported by Berk et al. [12]. Using direct plethysmography for evaluation of bronchial patency during local cooling or heating of various body areas. Our data showed that cold stimulation of forearm and hand skin also limited the maximum ventilatory capacity without leading to bronchoconstruction [11]. This might be explained by inhibition of the respiratory center by the thermoregulatory center, mediated by cutaneous thermoreceptors.
Initial spirometric parameters determined before forearm or hand heating (M ± m) VC, l
FVC, l
FEV1, l
PEF, l/s
Tiffeneau index, %
MEF25, l/s
MEF50 , l/s
MEF75 , l/s
Forearm
4.6 ± 0.13
4.4 ± 0.14
4.1 ± 0.14
8.7 ± 0.63
88.3 ± 1.80
8.2 ± 0.60
5.7 ± 0.37
2.5 ± 0.29
Hand
4.6 ± 0.14
4.3 ± 0.15
4.0 ± 0.17
8.2 ± 0.62
89.2 ± 2.24
7.9 ± 0.59
6.1 ± 0.41
2.8 ± 0.28
Heated area
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Thus, local heating, as well as local cooling, of the skin causes pronounced [15] and statistically significant changes in the spirometric parameters. The persistence of these changes after the termination of stimulation and even after the return of the skin temperature to the its level is presumably related to a residual response to the signal generated by thermoreceptors activated by temperature changes [17, 18]. It was shown that thermal stimuli significantly change the levels of transmitters [16] and hormones in the blood [17, 18]. CONCLUSION Thus, changes in the respiratory volume parameters induced by heating or cooling of the forearm or hand skin followed similar patterns but were quantitatively different. Changes in the flow parameters demonstrated that local heating or cooling decreased the peak expiratory flow. At the same time, unlike cooling, heating significantly increased the MEF50 and MEF75. This may indicate that cooling limits the maximum inspiration without affecting expiration, whereas heating produces only a moderate effect on inspiration and significantly limits expiration. The increase in the MEF50 and MEF75 observed along with a decrease in the VC and FVC may be accounted for by the fact that stimulation of thermoreceptors limits the expiratory effort, causing its sharp cessation and artifactual elevation of the MEF50 and MEF75. REFERENCES 1. Josenhaus, W.T., Melville, G.N., and Ulmer, W.T., The effect of Facial Stimulation on Airway Conductance in Healthy Man, Can. J. Physiol. Pharmacol., 1969, vol. 47, no. 5, p. 453. 2. Keatinge, W.R. and Nadel, J.A., Immediate Respiratory Response to Sudden Cooling of the Skin, J. Appl. Physiol., 1965, vol. 20, p. 65. 3. Muchtar, M.R. and Patrick, J.M., Face Immersion Prolongs Maximal Breath-Holding in Man, J. Physiol. (London) 1985, vol. 361, p. 67. 4. Glebovskii, V.D. and Baev, A.V., Stimulation of Trigeminal Receptors of the Nasal Mucous Membrane by Respired Air Flow, Fiziol. Zh. SSSR im. I.M. Sechenova, 1984, vol. 70, no. 4, p. 1534. 5. Burgess, K.P. and Whitelaw, W.A., Effect of Nasal Cold Receptors on the Pattern of Breathing, J. Appl. Physiol., 1988, vol. 64, p. 371.
6. Grishin, O.V. and Simonova, T.G., Lung Ventilation and Gas Interchange during Breathing with Air of Various Temperatures, Fiziol. Chel., 1998, vol. 24, no. 5, p. 44. 7. Koskela, H.O., Rasanen, S.H., and Tukiainen, H.O., The Diagnostic Value of Cold Air Hyperventilation in Adults with Suspected Asthma, Resp. Med., 1997, vol 91, p. 470. 8. Kozyreva, T.V. and Simonova, T.G., Temperature Reception and Human Respiration Parameters under Normal Conditions and during Local Cooling, Fiziol. Zh. SSSR im. I.M. Sechenova, 1991, vol. 37, no. 3, p. 48. 9. Kozyreva, T.V. and Simonova, T.G., Response of the Respiratory System to Sudden Local Cooling, Fiziol. Chel., 1994, vol. 20, no. 4, p. 177. 10. Kozyreva, T.V. and Simonova, T.G., Modulating Effect of Peripheral Thermoreceptors on Human Respiration, Vestn. Ross. Akad. Med. Nauk, 1998, no. 9, p. 14. 11. Simonova, T.G. and Kozyreva, T.V., Effect of Forearm and Hand Skin Cooling on Spirometric Parameters in Man, Environmental Ergonomics. IX, Werner, J. and Hexamer, M., Eds., Aachen: Shaker, 2000, p.173. 12. Berk, J.L., Lenner, K.A., and McFadden, E.R., Coldinduced Bronchoconstriction: Role of Cutaneous Reflexes vs. Direct Airway Effects, J. Appl. Physiol., 1987, vol. 63, p. 659. 13. Vecchiet, L., Flaccol, L., Marini, I., et al., Effects of Cold Stimulus of the Chest Wall on Bronchial Resistance, Respiration, 1985, vol. 47, p. 253. 14. Davies, S.M., Goldsmith, G.E., Hellon, R.F., and Mitchell, D., Facial Sensitivity to Rates of Temperature Changes: Neurophysiological and Psychological Evidence from Cats and Humans, J. Physiol. (London), 1983, vol. 344, p. 161. 15. Quanjer, P., Tammeling, J., Cotes, J., et al., Lung Volumes and Forced Ventilatory Flows: Report of the Working Party on Standardization of Lying Function Tests, European Community for Steel and Coal, Pul’monologiya (Suppl.), 1993. 16. Bruck, K. and Zeisberger, E., Adaptive Changes in Thermoregulation and Their Neuropharmacological Basis, Pharmacol. Ther., 1986, vol. 35, p. 163. 17. Depocas, F. and Benhrens, W.A., Levels of Noradrenaline in Plasma during Thermogenesis Induced by Cold Exposure or by Noradrenaline Infusion in Warm- and Cold-Acclimated Rats, Effect Thermogenegis, BaselStuttgart, 1978, p. 135. 18. Barrand, M.A., Danncey, M.I., and Ingram, D.L., Changes in Plasma Noradrenaline and Adrenaline Associated with Central and Peripheral Thermal Stimuli in the Pig, J. Physiol. (London), 1981, vol. 316, p. 139.
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