Feet In Ice Water Research Articles

Pain-induced effects on the pupillary light response under high and low illumination conditions.

The present study investigated the impact of two different light intensities on the pain-modulated pupillary light response (PLR). Additionally, it aimed to demonstrate parasympathetic and sympathetic influences on PLR parameters in response to pain, as predicted by functional models. A total of 24 participants were included in a randomized, repeated-measures design. The PLR was measured in response to both dark and bright light stimuli within two test cycles. Pain was induced using the cold pressor test (CPT), which involved immersing participants' feet in ice water. PLR measurements were taken during baseline and ice-water immersion within each test cycle. The assessed PLR parameters included initial diameter (INIT), latency (LAT), amplitude (AMP), and re-dilation time (ReDIL25). Along with these parameters, heart rate (HR) and pain ratings were also computed and analyzed. The CPT caused moderate pain in participants, and the resulting PLR parameters were found to be congruent with the expected parasympathetic and sympathetic nervous system activities. Although the luminance of the stimulus did influence PLR parameters, no interaction with pain exposure was found. The results showed that different aspects of pain experienced by an individual, as modulated through the sympathetic and parasympathetic nervous systems, are visible in their pupillary reactions to light. Notably, within the range used in the current study, light intensity did not significantly affect the pain-related PLR effects.

Effect of cryotherapy on post-exercise cardiac autonomic recovery in mixed martial arts (MMA) fighters: A Randomized Clinical Trial

Background: Cryotherapy brings benefits for muscle recovery and reduction of lactate thresholds in fighters; however, the effect of cryotherapy on the autonomous cardiac recovery (ACR) of wrestlers is not yet defined in the scientific literature. Objective: To analyze the effect of cryotherapy on ACR after simulated combat exercise in mixed martial arts (MMA) fighters. Methods: Crossover randomized clinical trial with a sample of 17 MMA fighters (male, age >18 years). There was simulated combat of three rounds of MMA; each round lasted 5-min, there were the 60s between rounds. ACR was assessed by resting heart rate (RHR), which was monitored by a portable Polar-FT1® device. We measured RHR in the interval between the rounds at the 30s and 60s of rest in the conditions: without cryotherapy (Control), application of an ice pack in the thoracic region (TC); Immersion of feet in ice water (FC). Results: At 30-s of RHR, the control condition was better than FC to reduce RHR in rounds 1 and 2 (p<0.05; η2p:0.28). At the 60s of RHR, the control condition was better than FC and TC (p<0.05; η2p:0.32). The control condition had a better RHR recovery rate than the FC condition after rounds one (η2p: 0.23), two (η2p: 0.46), and three (η2p: 0.27) (p<0.05). The TC condition did not show differences concerning the control and FC conditions. Conclusion: Cryotherapy applications in the thoracic region and by complete immersion of the feet did not generate significant effects on the ACR of MMA fighters.

Effect of training on treadmill performance, aerobic capacity, and body responses to acute cold exposure

An attempt was made to test the hypothesis that regular physical activity at the anaerobic threshold is able to stimulate an increase in the amount of body fat brown or beige, which can manifest itself in increasing lactate utilization during exercise and increase the reactivity in response to acute regional cooling. The methods used are: ramp test, regional acute cold exposure, measurement of gas exchange, lactate and glucose in the blood, heart rate, and heart rate variability, blood pressure and respiration variability at rest and during standard functional tests; infrared thermal imaging, statistical methods of results analysis. Workout 10 physically active volunteers (7 males and 3 females) on a treadmill at a speed corresponding to 75-80% of the persona VO2max for 30 minutes 3 times per week at a fixed ambient temperature 21-22°C for 6 weeks resulted in a significant (from 19 to 39%) increase in test work duration but VO2max on average changed little. The increase in power of anaerobic threshold was associated with a sharp slowdown in the accumulation of lactate in progress of ramp test. Lactate utilization rate during the recovery period, on the contrary, increased. In general, significantly increased work efficiency at a test load. Not revealed noticeable changes in the condition and response to a standard functional tests of autonomic systems, as judged by heart rate variability, blood pressure and respiration variability at rest and during orthostatic tests and imposed breathing rhythm. The functional response of the body to acute cold exposure (1 minute cooling of the feet in ice water) is not changed after a cycle of training--either in terms of metabolism (oxygen consumption, etc.), or the dynamics of the skin temperature in areas of most probable location of brown adipose tissue (BAT). These data do not confirm the previously expressed (2010) hypothesis about the function of BAT as a universal homeostatic instrument in the body. Probably, if under the influence of physical activity and hormone irisin produced by muscles the formation of the beige adipose tissue is stimulated, the one that is involved in lactate utilization, but is not involved in thermoregulatory responses.

Detection of diminished response to cold pressor test in smokers: Assessment using phase-contrast cine magnetic resonance imaging of the coronary sinus

PurposeThe purposes of this study were to evaluate the reproducibility for measuring the cold pressor test (CPT)-induced myocardial blood flow (MBF) alteration using phase-contrast (PC) cine MRI, and to determine if this approach could detect altered MBF response to CPT in smokers. Materials and methodsAfter obtaining informed consent, ten healthy male non-smokers (mean age: 28±5 years) and ten age-matched male smokers (smoking duration ≥5 years, mean age: 28±3 years) were examined in this institutional review board approved study. Breath-hold PC cine MR images of the coronary sinus were obtained with a 3T MR imager with 32 channel coils at rest and during a CPT performed after immersing one foot in ice water. MBF was calculated as coronary sinus flow divided by the left ventricular (LV) mass which was given as a total LV myocardial volume measured on cine MRI multiplied by the specific gravity (1.05 g/mL). ResultsIn non-smokers, MBF was 0.86±0.25 mL/min/g at rest, with a significant increase to 1.20±0.36 mL/min/g seen during CPT (percentage change of MBF (∆MBF (%)); 39.2%±14.4%, p<0.001). Inter-study reproducibility for ∆MBF (%) measurements by different MR technologist was good, as indicated by the intraclass correlation coefficient of 0.93 and reproducibility coefficient of 10.5%. There was no significant difference between smokers and non-smokers for resting MBF (0.85±0.32 mL/min/g, p=0.91). However, ∆MBF (%) in smokers was significantly reduced (-4.0±32.2% vs. 39.2±14.4%, p=0.011). ConclusionPC cine MRI can be used to reproducibly quantify MBF response to CPT and to detect impaired flow response in smokers. This MR approach may be useful for monitoring the sequential change of coronary blood flow in various potentially pathologic conditions and for investigating its relationship with cardiovascular risk.

Epicardial Fat Volume Is Associated With Coronary Microvascular Response in Healthy Subjects: A Pilot Study

Epicardial fat (EF) is an active ectopic fat depot, which has been associated with coronary atherosclerosis, and which could early influence endothelial function. We thus investigated the relationship between EF and endothelium-dependent vasoreactivity of the coronary microcirculation, in highly selected healthy volunteers. Myocardial blood flow (MBF) was determined by measuring coronary sinus flow with velocity-encoded cine magnetic resonance imaging (MRI) at 3T. We measured MBF at baseline and in response to sympathetic stimulation by cold pressor testing (CPT) in 30 healthy volunteers with normal left ventricular (LV) function (age 22 ± 4 years, BMI = 21.3 ± 2.8 kg/m(2)). EF volume was volumetrically assessed by manual delineation on short-axis views. CPT was applied by immersing one foot in ice water for 4 min. Mean EF volume was 56 ± 26 ml and mean LV mass 100 ± 28 g. CPT significantly increased heart rate (HR) by 32 ± 19%, systolic blood pressure by 14 ± 10%, and rate-pressure product by 45 ± 25%, P < 0.0001. The increase in HR, reflecting sympathetic stimulation, was not influenced by sex, age or EF volume. CPT induced a decrease in coronary vascular resistance (135 ± 72 vs. 100 ± 42 mm Hg.ml(-1).min.g, P = 0.0006), and a significant increase in MBF (0.81 ± 0.37 vs. 1.24 ± 0.56 ml.min(-1).g(-1), P < 0.0001). Interestingly, we found a significant negative correlation between EF volume and ΔMBF (r= - 0.40, P = 0.03), which remained significant after adjusting for ΔHR. ΔMBF was also associated with adiponectin (r = 0.41, P = 0.046), but not with waist circumference, BMI, C-reactive protein, lipid or glycemic parameters. In multivariate analysis, adiponectin and EF volume remained both independently associated with ΔMBF. A high EF amount is associated with a lower coronary microvascular response, suggesting that EF could early influence endothelial function.

Effect of Reduced Plantar Sensation on Human Gaits on Various Terrains

The aim of this study is to investigate the effects of plantar tactile sensibility on the gaits of subjects walking on regular and irregular terrains. We took 3-dimensional measurements of gait motions with a method of ice immersion to reduce plantar sensation, and we compared it to the measurements under normal (not iced) conditions. The subjects were 8 healthy men (21.9±0.8 years old). In these experiments, the subjects immersed their feet in ice water for 30 minutes. We conducted the experiments on even terrain and uneven terrain (48 trials in total per subject). We also measured 6-axis plantar reaction forces of subjects while they were walking. The subjects were 5 healthy young men (22.6±0.5 years old), and there were 25 trials in total. As a result, the results of the gait velocity (p &lt;0.07), step length (p &lt;0.96), and step width (p &lt;0.5) on even terrains did not change significantly after the ice immersion. By contrast, on uneven terrain with a gait of free velocity, the gait velocity (p &lt;0.01) and the step length (p &lt;0.01) significantly decreased after the ice immersion. On uneven terrain with a gait of maximum velocity, the step length (p &lt;0.01) significantly decreased, and the step width variability (p &lt;0.03) increased after the ice immersion. Force variability in the back-to-front direction (p &lt;0.03) and moment variability in pitch axis (p &lt;0.004) significantly decreased, and roll axis moment variability (p &lt;0.05) significantly increased after the ice immersion. These results support the hypothesis that reduced plantar sensation has a significant effect on human gaits, especially when a person is walking on uneven terrain.

Cardiovascular Responses to Stress and Disease Outcomes

The idea that stress can contribute to disease has been a part of the lore of medicine since the ancient Greeks. In the field of psychosomatic medicine, Alexander1 argued that emotional dispositions could lead to persistent bodily response biases that could contribute to organic disease. In hypertension research, Hines and Brown2 proposed that an increased risk for hypertension could be revealed by an exaggerated blood pressure response to the stress of immersing a hand or foot in ice water (the cold pressor test). These proposals contributed to the more recent “stress reactivity hypothesis” that a highly reactive psychological disposition or physiological constitution could increase risk for disease.3 Despite the intuitive appeal of this idea, proof of a reactivity connection to cardiovascular disease has been very difficult to produce. Barriers to such proof include the gradual development of hypertension and heart disease, resulting in the need for long follow-up periods on large numbers of persons; the presence of confounding variables, such as higher rates of smoking in persons experiencing stress in life; and the lack of standardized psychological stress paradigms analogous to the exercise protocols used in cardiology. Additional difficulty arises from uncertainty over the stability of emotional and stress responses in a given individual. …

Regional cooling significantly reduces liposomal doxorubicin-induced palmar-plantar erythrodysesthesias (PPE) in patients with recurrent ovarian cancer

18507 Objective: To evaluate the effect of regional cooling on the incidence and severity of liposomal doxorubicin-induced PPE in patients with recurrent ovarian cancer. Methods: Following IRB-approval, a retrospective chart review identified all patients treated with liposomal doxorubicin for recurrent ovarian cancer from 7/00 through 7/05. It was then determined whether patients received a regional cooling protocol, which involved placing hands and feet in ice water during chemotherapy infusion. Information was collected including patient demographics, prior chemotherapy, and grade and severity of PPE. Results: 73 women were treated for recurrent ovarian cancer with liposomal doxorubicin over the 5-year period. The median age was 58 years (range 24 to 82). The number of cycles ranged from 2 to 27 (median of 5). Liposomal doxorubicin dosages were available for 69 patients. Of the 69 patients, 4 patients were treated at 30 mg/m2, 64 patients were treated at 40mg/m2, and 1 patient was treated at 50mg/m2. The number of prior chemotherapy regimens ranged from 1 to 6 (median of 2.4) and the total number of all prior cycles ranged from 6 to 57 (median of 10). 25 of 73 patients (34%) were treated using the regional cooling protocol, while 48 of 73 (66%) were not. All incidences of PPE occurred in patients treated at the 40mg/m2 dosing. The overall incidence of PPE in the regional cooling group was 24% compared to 54% in the non-regional cooling group (p = 0.0067). In the regional cooling group, 12% had grade 1 PPE, 8% had grade 2 PPE, 4% had grade 3, and none developed grade 4 PPE. Of the 48 patients without regional cooling, 19% had grade 1 PPE, 15% had grade 2 PPE, 15% had grade 3, and 2 of 4% had grade 4 PPE. Of the 25 patients receiving regional cooling, 1 patient (4%) required discontinuation of liposomal doxorubicin due to grade 3 PPE while 11 patients of the 48 patients who did not receive regional cooling (23%) required discontinuation due to PPE (p = 0.048). The incidence of PPE was not associated with age at diagnosis or total number of previous chemotherapy cycles. Conclusions: Regional cooling is effective in significantly reducing the incidence and severity of liposomal doxorubicin-induced PPE in patients with recurrent ovarian cancer. No significant financial relationships to disclose.

Metronidazole: Newly Recognized Cause of Autonomic Neuropathy

Metronidazole is a commonly used antibiotic prescribed for the treatment of anaerobic and protozoal infections of the gastrointestinal and genitourinary tracts. It is associated with numerous neurologic complications, including peripheral neuropathy. Neuropathy is typically detected in patients on chronic therapy, although it has been documented in those taking large doses for acute infections. Numerous case reports have been published describing motor and sensory neuropathy, yet autonomic neuropathy has not been described with metronidazole use. A previously healthy 15-year-old girl presented with complaints of burning pain in her feet following a short course of metronidazole for vaginitis. She could obtain pain relief only by submerging her feet in ice water. Examination revealed cold and swollen lower extremities that became erythematous and very warm when removed from the ice water. Temperature perception was reduced to the upper third of the shin bilaterally. Deep tendon reflexes and strength were preserved. Nerve conduction studies demonstrated a peripheral neuropathy manifested by reduced sensory nerve and compound muscle action potentials. Reproducible sympathetic skin potential responses could not be obtained in the hand and foot, providing evidence of a concurrent autonomic neuropathy. A thorough evaluation revealed no other cause for her condition. Repeated nerve conduction studies and sympathetic skin potentials returned to normal over the course of 6 months, paralleling the patient's clinical improvement. Metronidazole is a potential cause of reversible autonomic neuropathy.

Effects of hypothermic anesthesia of the feet on vibration-induced body sway and adaptation

The aim of this study was to investigate the significance of information from the plantar cutaneous mechanoreceptors in postural control and whether postural control could compensate for reduced cutaneous information by adaptation. Sixteen healthy subjects were tested with eyes open or eyes closed with hypothermic and normal feet temperature during posturography where body sway was induced by vibratory proprioceptive stimulation towards both calf muscles. The hypothermic anesthesia was obtained by cooling the subject's feet in ice water for 20 minutes. Body movements were evaluated by analyzing the anteroposterior and lateral torques induced towards the supporting surface by a force platform during the posturography tests. The reduction of cutaneous sensor information from the mechanoreceptors of the feet significantly increased the vibration-induced torque variance mainly in the anteroposterior direction. However, the effects of disturbed mechanoreceptors information was rapidly compensated for through postural adaptation and torque variance was in level with that without anesthesia within 50 to 100 seconds of stimulation, both when standing with eyes open and eyes closed. Our findings suggest that somatosensory input from mechanoreceptors in the foot soles contribute significantly in maintaining postural control, but the sensory loss could be compensated for.

EFFECTS OF AEROBIC EXERCISE ON CARDIOVASCULAR RESPONSES DURING THE COLD PRESSOR TEST IN AFRICAN AMERICANS

Previous studies have shown that during the cold pressor test (CPT) an increase in systolic blood pressure (SBP) ≥ 25 mm Hg above baseline is associated with an increased risk of developing hypertension(HT). We investigated the effects of aerobic exercise training on cardiovascular reactivity (CR) during the CPT in normotensive college-aged African American (AA) males. Ten aerobically-trained males and ten similar non-trained males served as subjects. The CPT consisted of immersing the foot in ice water (5°C) for two minues. The exercise training protocol consisted of eight weeks of cycling at 70% peak oxygen uptake (VO2peak), three days/week for 30 minutes/session. Oxygen uptake was determined using the open-circuit method. Blood pressure (BP) was assessed noninvasively using the continuous method of tonometry. Cardiac output(CO) and stroke volume (SV) were measured using impedance cardiography. Total peripheral vascular resistance (TPR) was calculated using the mean arterial BP (MABP) and CO values. Cardiac neural activity (CNA) was assessed by time domain and frequency domain analysis of heart rate variability. CR was determined by contrasting differences in resting measures and those recorded during the CPT. After training, VO2peak in the trained group increased 16% (pre-trained = 33.6 ± 2 vs. post-trained = 40.1 ± 1 ml kg−1 min−1) (P < 0.05). No significant change in VO2peak was found in the control group. In the exercise-trained group SBP, diastolic BP, MABP, heart rate, SV, CO, and TPR differences tended to be lower than before training (p > 0.05). We observed that in the exercise-trained group pre and post-trained SBP difference values were 27.4 ± 4 and 21.7 ± 6 mm Hg respectively. This magnitude of decrease in the post-trained SBP difference score is of clinical significance since it is indicative of a reduction in the risk for developing HT. In the control group there were no changes in the measured CR difference scores. Analysis of difference scores for CNA determined by assessing R-R interval (SDNN) and spectral analysis illustrated no difference in the exercise-trained and non-trained groups. In this study exercise training had no significant effect on the CR to behavioral stress. However, our data are of clinical significance since the training program used in this study produced a difference in the SBP response to stress. A change such as this may reduce the risk of HT in AA. Supported by NIH GM-08016.

Phase I Safety Assessment of Intrathecal Neostigmine Methylsulfate in Humans

In dogs, sheep, and rats, spinal neostigmine produces analgesia alone and enhances analgesia from alpha 2-adrenergic agonists. This study assesses side effects and analgesia from intrathecal neostigmine in healthy volunteers. After institutional review board approval and informed consent, 28 healthy volunteers were studied. The first 14 volunteers received neostigmine (50-750 micrograms) through a #19.5 spinal needle followed by insertion of a spinal catheter. The remaining 14 volunteers received neostigmine through a #25 or #27 spinal needle without a catheter. Safety measurements included blood pressure, heart rate, oxyhemoglobin saturation, end-tidal carbon dioxide, neurologic evaluation, and computer tests of vigilance and memory. Analgesia in response to ice water immersion was measured. Neostigmine (50 micrograms) through the #19.5 needle did not affect any measured variable. Neostigmine (150 micrograms) caused mild nausea, and 500-750 micrograms caused severe nausea and vomiting. Neostigmine (150-750 micrograms) produced subjective leg weakness, decreased deep tendon reflexes, and sedation. The 750-micrograms dose was associated with anxiety, increased blood pressure and heart rate, and decreased end-tidal carbon dioxide. Neostigmine (100-200 micrograms) in saline, injected through a #25 or #27 needle, caused protracted, severe nausea, and vomiting. This did not occur when dextrose was added to neostigmine. Neostigmine by either method of administration reduced visual analog pain scores to immersion of the foot in ice water. The incidence and severity of these adverse events from intrathecal neostigmine appears to be affected by dose, method of administration, and baricity of solution. These effects in humans are consistent with studies in animals. Because no unexpected or dangerous side effects occurred, cautious examination of intrathecal neostigmine alone and in combination with other agents for analgesia is warranted.

Vascular effects of a modified cold pressor test in spinal cord injured and able-bodied men

The vascular reflex responses of the hands of ten spinal cord injured (SCI) men (sensory and motor complete) to a modified cold pressor test were compared to ten age-matched, able-bodied men. The skin temperature of the left index finger was measured before, during, and after the immersion of the feet in ice water for 20 seconds. The heart rate and blood pressure were measured 5 minutes before and 15 minutes after the cold stimulus. The able-bodied subjects showed an immediate vasoconstriction and fall in finger temperature after cold stimulation of the feet, followed by vasodilation and an increase in finger temperature (p < .0001), whereas, the SCI subjects did not show any change in finger temperature during this test. Prior to application of the cold stimulus, the SCI subjects had a significantly low diastolic blood pressure compared with the diastolic blood pressure of able-bodied subjects, which “normalized” after the cold stimulus. These data support the concept that regulation of vascular tone occurs at both spinal and supraspinal levels.

A comparison of cardiovascular and autonomic adjustments to three types of cold stimulation tasks

Two types of ‘cold pressor’ tasks are used frequently in research settings: immersing the hand or foot in ice water, and applying an icebag to the forehead. Both tasks have commonly been selected as ‘α-adrenergic’ tasks due to expected increases in blood pressure and peripheral resistance. However, the forehead cooling task has been used by others to produce increased vagal tone due to the elicitation of the ‘diving reflex’ and subsequent bradycardia. This differs from the prototypical increase in heart rate during hand immersion. The present study directly compared the cardiovascular adjustments of hand immersion and forehead stimulation. As stimulation of the trigeminal nerve is thought to increase vagal activity during forehead cooling, a third condition in which most of the face was covered with an icebag was included to ostensibly stimulate more of the trigeminal. 18 males had counterbalanced exposures to hand immersion, forehead cooling, and facial cooling for 90 s each. Cardiovascular variables derived from impedance cardiography and the ECG were measured. Respiration was paced at 14 breaths/min to facilitate comparisons of respiratory sinus arrhythmia across conditions. No differences among baseline or tasks were found for respiratory rate or cardiac output. The pattern of results for hand immersion was that of increased heart rate with moderate blood pressure increases. In contrast, the forehead and facial cooling tasks elicited small heart rate decreases with little change in blood pressure. Facial cooling elicited significantly more vagal activation than hand cooling as indexed by respiratory sinus arrhythmia. The patterns of response for facial and forehead cooling were almost identical. Probable reasons for the lack of significant blood pressure responses during the facial and forehead cooling are discussed.

Vascular responses to temperature in the foot of the giant fulmar,Macronectes giganteus

1. Blood circulation to the leg of an antarctic bird, the giant fulmar,Macronectes giganteus, has been studied in response to changing the temperature of the ambient environment including immersion of the feet in ice water. 2. Measurements done include blood flow to the leg by an electromagnetic flow meter, blood pressure in the carotid artery and locally in a leg artery and vein, intravenous and arterial blood temperatures in the leg in addition to foot subcutaneous temperature and core temperature (deep pectoral temperature). 3. Blood flow to the lower leg varied between 10 ml/min and 40 ml/min during resting thermoneutral conditions. 4. Raising the core temperature by heating the central body increased foot blood flow to maximum values around 40 ml/min or 160 ml/min/100 g tissue. 5. Quick warming of the cold feet by immersion in hot water caused only slight increase in leg blood flow, whereas slow rewarming in air gave increasing leg blood flow when the local temperature of the foot increased from near zero to 35.6° C. 6. Sudden immersion of the foot in ice water (T = −2.0° C) elicited an immediate flow increase and a transient increase in foot arterial blood temperature. Venous pressure in the foot increased with blood flow while foot arterial pressure was unaltered. 7. The vasodilatation on ice immersion, termed the “cold flush” was followed by a gradual increase in vasoconstriction and reduced blood flow. After about 3 minutes fluctuations “huntings” appeared in leg blood flow and local temperatures in the foot. 8. The described circulatory changes are discussed in relation to thermal homeostasis of the bird and protection of the naked feet from cold shock and impairment of function on sudden cold exposure. Special reference is given to the phenomenon of cold vasodilatation earlier described on cold exposure of extremeties in mammals.