Heart Rate and Blood Pressure Responses to Warm Whirlpool Treatment - Article Example

 Heart Rate and Blood Pressure Responses to Warm Whirlpool Treatment Abstract Introduction: Warm whirlpool treatments are increasingly becoming a means of relaxation with the sense of well-being it provides. Changes in hemodynamics of the body occur because of the changed warmer environment of the warm whirlpool environment and studies evaluating these changes during hot tub immersions have shown that these changes include the increase in heart rate and decrease in blood pressure. Aim: The aim of the study is to answer the question of how heart rate and blood pressure changes during a full body warm whirlpool treatment. Methods: The study used two healthy college age subjects in an experimental design that measured resting heart rate and blood pressure prior to immersion, measurement of heart rate and blood pressure during immersion of ten minutes, and recovery measures of heart rate and blood pressure subsequent to the immersion of ten minutes. The data collected was plotted on two graphs for analysis. Results: The study found that there was an increase in heart rate and decrease in blood pressure, but were not significant enough to warrant any risk to individuals with normal blood pressure. Conclusion: Though the risk factors for healthy individuals are not significant, given the hemodynamic changes that occur, there remains potential risk to individuals with treated stable hypertension that could cause adverse reactions. Introduction: A warm whirlpool consists of a heated pool in which high pressured jets that circulate the warm body focusing on the body of the individual. The effect of this dousing of the body with warm water according to Robiner, 1990, brings about an increased sense of well-being and a reduction in the any anxious feelings. As a result of this warm whirlpool treatments have become a popular means to relaxation (Robiner, 1990). This popular means of relaxation has its drawbacks and the first indication of this can be seen in the warning signs that are seen in the front of hot water spas, alerting individuals to the likely negative effects in the use of warm water baths over long periods of time. The rationale behind this lies in the warning by Kataoka and Yoshida, 2005, that warm water baths as is commonly used by the Japanese may have negative effects that arise from the thermal stimulus on hemodynamics. The human body in normal conditions has a temperature set point of 37 degrees Centigrade, which may get altered during the circadian rhythm, after sleep loss, during hypobaria, and subsequent to dehydration. The stability in temperature that the body maintains is achieved by maintaining a balance between the rate of heat production that occurs mainly through metabolism and rate of heat lost or gained from the environment. Normal rules of thermodynamics are involved in this transfer of heat from the body and to the body. Differences between the temperature the skin and the environment is the governing factor in the thermodynamics involved (Lloyd, 1994). The thermodynamics involved in the attempt of the body to maintain the set point temperature of 37 degrees Centigrade is responsible for the thermal stimulus on hemodynamics, and it is for this reason that causes Ishijima and Togawa, 1999, to maintain that bathing in hot water puts stress on the heart. According to Press, 1991, this stress on the heart originates from the increased pressure from the water causing vasodilation, profuse perspiration leading to a decrease in the extra-cellular volume of blood, increase in hematocrit levels with shortened clotting times, and an increase in the consumption of oxygen, due to the conditions of the environment saunas, spas, and hot tub baths. This raises the possibility of cardiac arrests resulting in patients during their use of saunas, spas and hot water tubs, with particular emphasis on individuals with a history of cardio-vascular problems (Press, 1991). Such an understanding of the hemodynamics associated with an individual in the environmental conditions of a hot tub baths, has caused physicians to warn individuals with elevated blood pressure levels and cardiac problems on the possible risks they face in hot water baths (Shin, Wilson & Wilson, 2003). Nagasawa, et al, 2001, point out that there is the risk of sudden death from hot water baths as such deaths have been associated with bathing in hot water. This study aims to answer the question of how heart rate and blood pressure changes during a full body warm whirlpool treatment. The purpose of the study is to observe changes in the heart rate and blood pressure that occur with a warm whirlpool treatment as against the heart rate and blood pressure at rest and hypothesize the reason why certain special populations are advised precautions in the use of warm whirlpool treatments or hot tub baths. The study revolves on the hypothesis that heart rate will increase with warm whirlpool treatment and there will be a decrease in blood pressure. Literature Review: Several studies have been undertaken to evaluate the possible risks associated with hot water tubs and produce evidence in support of the risk warning that have stemmed from the hemodynamics involved in the environments of saunas, spas and hot tub baths. Boone Westendorf and Ayres, 1999, provide information on a limited exposure of young subjects to a hot tub bath. Based on a study of five young subjects, who were exposed to a fifteen minutes immersion in a hot tub bath maintained at a temperature of 39 degrees Centigrade, Boone, Westendorf, and Ayres, 1999, found that at fifteen minutes there was an increase in heart rate, and cardiac output, while there was a decrease in mean arterial pressure and systolic blood pressure. The increase in cardiac output was attributed to the decrease in systemic vascular resistance and this increase in cardiac output along with the increase in heart rate was the response to the increased metabolism that resulted from the immersion in a hot tub bath. In the opinion of the others exposure in a hot water bath for the limited time of fifteen minutes posed no health risks to young subjects (Boone, Westendorf, & Ayres, 1999). Support for increase in heart rate and decrease in blood pressure is found in the study of Miwa, et al, 1994, which provides a comparative picture of cardiovascular responses in the case of hot tub bath (40 degrees Centigrade) and normo-temperature tub bath (34.5 degrees Centigrade) over an extended time of sixty minutes for healthy young males. Findings from the normo-temperature bath showed that besides a decrease in heart rate all other variables demonstrated no significant change, while findings from hot tub bath showed that after ten minutes from the entry in the bath the mean blood pressure decreased while there was an increase in heart rate and skin blood flow, while at the same time it was observed that there was an increase in the core temperature. This rise in core temperature during immersion in a hot tub bath for more than ten minutes has been attributed as the cause for the cardiovascular changes observed (Miwa, et al, 1994). The Katoaka and Yoshida study, 2005, on a young healthy adults, comparing the effects of hot tub immersion at 38 degrees Centigrade and forty one degrees Centigrade give support to the evidence that there is hardly any significant increase in heart rate and blood pressure in hot tub baths where the temperature is maintained at near normal temperature level of the human body. Insight into the differences in the cardiovascular response to changes in environment on the basis of age during a hot tub bath, and the study Nagasawa, et al, 2001, provides the evidence for this, in its comparison of elderly men (mean age of seventy-five years) and young men (mean age twenty-seven years), who were immersed up to their shoulders in the sitting position in hot tub bath maintained at forty degrees Centigrade for a period of ten minutes. In the case young subjects blood pressure decreased during this immersion, while in the elderly, blood pressure was at its maximum value just at the start of the immersion and a slight decline was observed after four minutes from the start of the immersion. Again, in the case of the young subjects the heart rate was found to increase, while a fluctuation was noted in the case of the elderly. This fluctuation consisted of a sudden increase in heart rate at the start of the immersion that subsequently decreased on continuing the immersion. In their conclusion the authors warn that there is the risk of hypotensive syncope that may lead to drowning in hot tub baths (Nagasawa, et al, 2001). This warning is supported by the Katoaka and Yoshida study, 2005, which found that there is the risk of dizziness due to the hemodynamic changes in hot water baths and recommended that hot tub baths at 41 degrees Centigrade should be for five minutes or less, and hot tub baths at 38 degrees Centigrade should not extend beyond ten minutes. Shin, Wilson & Wilson, through their study in 2003 add to the available knowledge on the effects of hot tub baths by providing evidence in the treated hypertension and including women in their study. The study compared the variations in blood pressure and heart rate in two groups. The first group consisted of male and female subjects in the age group of forty-three to seventy-six years having stable and treated hypertension. The second group consisted of a mix of males and females without hypertension in the age group nineteen to eighty-three years. The temperature of the hot tub bath was maintained at forty degrees Centigrade and the period of immersion was for ten minutes. A decrease in blood pressure was observed in both groups, while the heart rate was found to increase in both groups, with the only difference noted in that there was a slightly lower maximum increase in heart rates in the case of group with treated hypertension. This has made the authors conclude that hot tub baths of up to ten minutes is safe even for individuals with treated stable hypertension (Shin, Wilson, & Wilson, 2003). The evidence that emerges from these studies show variations, but in most cases are in agreement that there is the risk of increased heart rate and decreased blood pressure in hot tub baths and that the time spent in hot tub baths need to be restricted based on the temperature of the hot tub bath, and should not extend beyond ten minutes. Methods and Materials: Research Design: The study employs a quantitative methodology, with it designed on an experimental basis, which is suitable for the noting changes in variables through an intervention. The subjects used in the study are two normotensive, healthy college age volunteers in the age group twenty-two years to twenty-eight years. One subject was male, while the other was female. The male subject 22 years old, weighed 160 lbs and was 70 in tall, while the female subject was 28 years old, weighed 185 lbs and was 70 in tall. Experimental Protocol: The heart rate was taken every thirty seconds for six minutes, while blood pressure was monitored every two minutes for six minutes prior to immersion in the warm whirlpool treatment. The subjects were then immersed in a sitting position up to their shoulders in a warm whirlpool for ten minutes and their heart rate was monitored every thirty seconds and blood pressure monitored every two minutes. The water in the warm whirlpool was maintained at a temperature of 105 degrees Fahrenheit. At the end of ten minutes, the subjects came out of the warm whirlpool and their recovery measures of heart rate and blood pressure were taken by monitoring their heart rate every thirty second and their blood pressure every two minutes. Equipment Used: For the purposes of monitoring the heart rate of the subjects as required in the design of the study a polar heart rate monitor was employed. For taking the blood pressure of the subjects in keeping with the research design a regular size blood pressure cuff and a stethoscope was used. The warm water whirlpool treat on the subjects was through the means of a whirlpool tub manufactured by Ille Electric Company. It was fitted with a 0.25 HP motor for creating the water jets and circulating the water. The temperature in the whirlpool tub could be regulated by the means of a thermostat and employing this temperature regulator the temperature of the water in the whirlpool tub was maintained at 105 degreed Fahrenheit. Data Collection and Analysis: The data collected on the through the measurements of heart rate and blood pressure of the subject prior to immersion, during immersion and during recovery were recorded in data collection sheets. The data was collated and since there were two subjects, two separate graphs were used to plot the two measures of heart rate and blood taken during the procedure of the experiment. In the case of the heart rate graph heart rate on the Y axis was plotted against time on the X axis. To obtain a clear picture the interval of time on the X axis was thirty seconds, while heart rate ascended at an interval of twenty beats on the Y axis. In plotting the blood pressure graph time was taken in the same manner on the X axis, while blood pressure ascended in units of 20 mmHg on the Y axis. (Please see Appendix – 1 and Appendix – 2). Ethical Considerations: Since human volunteers were used as subjects in the experimental study all, it was the endeavor of the research team to try and meet all the regulations required in the use of human subjects for experimental research. To this end necessary sanctions were sought and from the administration authorities and the Ethics Committee of the institution, prior to the start of the study. For maintaining anonymity of the subjects and their information, the data sheets were coded in such a manner as to hide the identity of the subjects. The data sheets were kept securely during the period of the study and the collation and analyses of the data. The data was subsequently handed over to the Ethics Committee of the institution for safe keeping. Results and Findings: Analyses of the plotted graphs show that there was an increase in the heart rate and decrease in the blood pressure. The subjects did not demonstrate any palpitations, or chest pain, or dizziness and this can be attributed to the changes in hemodynamics in increased heart rate and decreased blood pressure caused by the warm environment of the whirlpool tub not being significant enough to bring on palpitations, chest pain, or dizziness. Discussion: The increase in heart rate during immersion in the warm whirlpool tub is in keeping with the findings of the studies of Boone Westendorf and Ayres, 1999, Miwa, et al, 1994, Nagasawa, et al, 2001, and Shin, Wilson & Wilson, 2003, wherein the heart rate was found to increase during immersion in warm hot tub baths. The decrease in blood pressure is on agreement with the findings of the studies of Boone Westendorf and Ayres, 1999, Miwa, et al, 1994, Nagasawa, et al, 2001, and Shin, Wilson & Wilson, 2003, wherein the blood pressure was found to decrease during immersion in warm hot tub baths. Nagasawa et al, show us that in the case of the elderly blood pressure peaked at the start of the immersion and then gradually decreased after the first four minutes of immersion in a hot water tub. The Miwa et al, 1994 and Kataoka and Yoshida, 2005 studies give evidence that this observed increase in heart rate and decrease in blood pressure that occurs in hot water tub immersions do not occur in the case of immersions in water tubs, where the temperature of the water is maintained at body temperature or near to the temperature of the body. This makes it evident that increases in heart rate and decreases in blood pressure are features of immersion in hot water baths and warm whirlpool tubs. Assumptions: This study has assumed that people with individuals with treated stable hypertension will demonstrate the same change as shown by individuals with normal blood pressure during immersion in warm whirlpool tubs, based on the findings of Shin, Wilson, & Wilson, 2003. Limitations: There are two limitations in the design of the study. The first limitation is the very small sample size of just two subjects that places restrictions on the validity of the study. In the opinion of the authors this limitation is mitigated to a certain extent by the study only attempting to verify the earlier findings of much larger studies and the findings are in keeping with these studies. The second limitation is that only subjects with normal blood pressure were subjects of the study and the authors do acknowledge that this limits the findings of the study to individuals with normal blood pressure. Conclusion: The risk involved in healthy individuals in warm whirlpool treatments is not significant enough to cause any alarm to these individuals. However, given that changes in heart rate and blood pressure occur, individuals with cardiovascular abnormalities need to show caution in their use of warm whirlpool treatments, given that there is the possibility that the normal responses in such individuals may be responsible for adverse reactions. The cautions that this study recommends for individuals with elevated blood pressure levels in the use of warm whirlpool treatments is to reduce the time of immersion in the warm whirlpool tubs, maintain the temperature of the water in the warm whirlpool tubs as near normal body temperature, increase awareness in this segment of the population regarding the potential risks involved in warm whirlpool treatments, and post notices at the warm whirlpool treatments facilities. This study also recommends that additional future studies be taken up to confirm and evaluate the extent of risks involved in individuals with hypertension in warm whirlpool treatments. Literary References Boone, T., Westendorf, T., & Ayres, P. (1999). Cardiovascular responses to a hot tub bath. Journal of alternative and complementary medicine, 5(3), 301-304. Ishijima, M., & Togawa, T. (1999). Chronodiagnostic acquisition of recovery speed of heart rate under bathing stress. Physiological measurement, 20(4), 369-375. Kataoka, Y. & Yoshida, F. (2005). The change of hemodynamics and heart rate variability on bathing by the gap of water temperature. Biomedicine & pharmacotherapy, 59(Suppl1), S92-S99. Lloyd, L. E. (1994). ABC of Sports Medicine: Temperature and Performance I: Cold. BMJ, 309,531-534. Miwa, C., Matsukawa, T., Iwase, S., Sugiyama. Y., Mano, T., Sugenoya, J., Yamaguchi, H., & Kirsch, K. A. (1994). Environmental medicine, 38(1), 77-80. Nagasawa, Y., Komori, S., Sato, M., Tsuboi, Y., Umetani, K., Watanabe, Y., & Tamura, K. (2001). Effects of hot bath immersion on autonomic activity and hemodynamics: comparison of the elderly patient and the healthy young. Japanese circulation journal, 65(7), 587-592. Press, E. (1991). The Health Hazards of Saunas and Spas and How to Minimize Them. American Journal of Public Health, 81(8), 1034-1037. Robiner, N. W. (1990). Psychological and physical reactions to whirlpool baths. Journal of Behavioral Medicine, 13(2), 157-173. Shin, T. W., Wilson, M., & T. W. (2003). Are hot tubs safe for people with treated hypertension? CMAJ, 169(12), 1265-1268. Appendix Appendix – 1 Heart Rate over Time Appendix – 2 Blood Pressure over Time Read More