Autonomic neuroscience : basic & clinical
-
Changes in heart rate variability (HRV) during anesthesia likely result from the interaction of hypnosis, surgical stimulation, analgesia and direct cardiovascular effects of drugs, but the interaction between these variables is unclear. This study was designed to characterize the impact of both surgical nociception and analgesia on HRV in propofol-anesthetized patients. ⋯ The nociception-analgesia balance is a direct determinant of HRV during surgical anesthesia. HFnu may behave like an early indicator of inadequate analgesia. These results have potential implication for monitoring adequacy of analgesia in healthy patients undergoing intravenous anesthesia. Additional work is needed for application across patient populations.
-
Clinical Trial
Bell-shaped relationship between central blood volume and spontaneous baroreflex function.
Spontaneous baroreflex function can be altered by acute changes in central blood volume. Both a reduction in spontaneous baroreflex function at central hypovolemia and augmentation at hypervolemia suggest a dose-effect relationship between central blood volume and spontaneous baroreflex function. However, this relationship has not been quantified over stepwise widespread changes in central blood volume. ⋯ Both spontaneous baroreflex indices of high-frequency transfer function gain (LBNP30, 17.4+/-3.2; LBNP15, 22.3+/-3.8; baseline, 25.6+/-4.1; NS15, 28.5+/-4.2 ms mm Hg(-1), ANOVA P=0.001) and of the sequence slope (LBNP30, 14.4+/-2.2; LBNP15, 17.2+/-2.5; baseline, 20.5+/-2.8; NS15, 24.5+/-3.1 ms mm Hg(-1), ANOVA P=0.001) increased stepwise from hypovolemia of LBNP30 to hypervolemia of NS15. However, these indices were lower at NS30 (high-frequency transfer function gain, 22.0+/-2.2 ms mm Hg(-1), post-hoc P=0.071; sequence slope, 17.7+/-1.7 ms mm Hg(-1), post-hoc P<0.05) than NS15 during hypervolemia. These results indicated that the relationship between central blood volume and spontaneous baroreflex function is apparently bell-shaped, with maximal augmentation at moderate hypervolemia.
-
Reflex control of heart rate is frequently impaired following myocardial infarction. This is referred to as depressed baroreflex sensitivity. The aim of these experiments was to assess the function of other autonomic reflexes in dogs with depressed baroreflex sensitivity. ⋯ In conclusion, activation of cardiac receptors with vagal afferent fibers elicited greater reflex inhibition of sympathetic outflow in dogs with depressed baroreflex sensitivity following myocardial infarction. These data suggest that these receptors are "sensitized". These results provide additional support for the hypothesis that depressed reflex control of heart rate following myocardial infarction is related to augmented afferent input from the left ventricle.
-
Randomized Controlled Trial
The effect of massage on cellular immunity, endocrine and psychological factors in women with breast cancer -- a randomized controlled clinical trial.
The purpose of this study was to examine the effect of repeated effleurage massage treatments compared with a visit control group on circulating lymphocytes by studying the number and activity of peripheral blood NK cells, CD4+ and CD8+ T cells in women with breast cancer. Furthermore, the effect of repeated effleurage massage treatments on the levels of cortisol in saliva and oxytocin in plasma as well as degree anxiety, depression and quality of life was studied. ⋯ Significant effect of effleurage massage on cellular immunity, cortisol, oxytocin, anxiety, depression or quality of life could not be demonstrated in this study. Several possible explanations to the results of this study are discussed.
-
Spinal cord stimulation (SCS) is a widely used clinical technique to treat ischemic pain in peripheral, cardiac and cerebral vascular diseases. The use of this treatment advanced rapidly during the late 80's and 90's, particularly in Europe. Although the clinical benefits of SCS are clear and the success rate remains high, the mechanisms are not yet completely understood. ⋯ SCS at the upper cervical spinal segments (C1-C2) increased cerebral blood flow, which is associated with a decrease in sympathetic activity, an increase in vasomotor center activity and a release of neurohumoral factors. This review will summarize the basic science studies that have contributed to our understanding about mechanisms through which SCS produces beneficial effects when used in the treatment of vascular diseases. Furthermore, this review will particularly focus on the antidromic mechanisms of SCS-induced vasodilation in the lower limbs and feet.