ABSTRACT
Objective To investigate the effect of catheter-based peripheral sympathetic denervation (CPSD) on peripheral artery sympathetic tone of New Zealand rabbits.Methods Twenty New Zealand rabbits were randomly divided into CPSD group and control group (each n =10).Endovascular radiofrequency ablation above the bifurcation of the abdominal aorta was performed on the rabbits in CPSD group.Norepinephrine was infused with continuous trans-arterial pumping in both two groups.And laser Doppler flowmetry was used to measure the peripheral microperfusion and temperature of right hindlimb of rabbits.The changes of the peripheral microperfusion and temperature before (resting state) and after norepinephrine infused (norepinephrine load state) were compared between the two groups.Results Eight rabbits completed the procedure in each group.The change of peripheral microperfusion between resting and norepinephrine load states in CSPD group was lower than that in control group ([-37.19±22.56]％ vs [-57.02％±10.12]％,P=0.04),whereas the change of temperature was not significantly different between the two groups ([0.35±0.50]℃ vs [-0.21± 1.83]℃,P=0.43),while significant difference was noticed when two rabbits with abnormal temperature change in control group were neglected ([0.34± 0.50] ℃ vs [-1.14 ±0.72] ℃,P＜0.01).Conclusion CPSD can be used to decrease the peripheral artery sympathetic tone of New Zealand rabbits,and may play an important role in relieving symptoms of critical limb ischemia.
ABSTRACT
Background & objectives: Regular practice of slow breathing has been shown to improve cardiovascular and respiratory functions and to decrease the effects of stress. This pilot study was planned to evaluate the short term effects of pranayama on cardiovascular functions, pulmonary functions and galvanic skin resistance (GSR) which mirrors sympathetic tone, and to evaluate the changes that appear within a short span of one week following slow breathing techniques. Methods: Eleven normal healthy volunteers were randomized into Pranayama group (n=6) and a non-Pranayama control group (n=5); the pranayama volunteers were trained in pranayama, the technique being Anuloma-Viloma pranayama with Kumbhak. All the 11 volunteers were made to sit in similar environment for two sessions of 20 min each for seven days, while the pranayama volunteers performed slow breathing under supervision, the control group relaxed without conscious control on breathing. Pulse, GSR, blood pressure (BP) and pulmonary function tests (PFT) were measured before and after the 7-day programme in all the volunteers. Results: While no significant changes were observed in BP and PFT, an overall reduction in pulse rate was observed in all the eleven volunteers; this reduction might have resulted from the relaxation and the environment. Statistically significant changes were observed in the Pranayama group volunteers in the GSR values during standing phases indicating that regular practice of Pranayama causes a reduction in the sympathetic tone within a period as short as 7 days. Interpretation & conclusions: Beneficial effects of pranayama started appearing within a week of regular practice, and the first change appeared to be a reduction in sympathetic tone.
ABSTRACT
BACKGROUND: Oxygen increases the cardiac vagal tone, blood pressure, systemic vascular resistance and vascular tone in healthy adults.This study assessed the autonomic tone according to different oxygen flow rates via different types of masks with using the heart rate variability (HRV) in the PACU after total intravenous anesthesia (TIVA). METHODS: We prospectively studied 27 patients after TIVA in the PACU.The 5 L group received oxygen via a simple mask with an oxygen rate of 5 L/min and the 10 L group received oxygen via a mask with a reservoir bag at a rate of 10 L/min in the PACU. We evaluated the HRV at the point of stabilization before anesthesia (BL), 5 min in the PACU (PACU 5), 30 min in the PACU (PACU 30) and 60 min in the PACU (PACU 60). RESULTS: In the 5 L group, the nuHF was increased to 42.4 +/- 24.2 at 60 min in the PACU as compared with 27.1 +/- 19.1 at 5 min in the PACU.In the 5 L group, the LFHFr was decreased to 2.3 +/- 2.1 at PACU 60 as compared with 6.6 +/- 9.7 at PACU 5 and the nuLF was decreased to 56.9 +/- 23.2 at PACU 60 as compared with 72.9 +/- 19.0 at PACU 5.There were no significant changes between the two groups at PACU 5, PACU 30 and PACU 60.The oxygen saturation was increased at PACU 60 compared with PACU 5 in the two groups. CONCLUSIONS: These finding indicates that 1 h of oxygen administration with 5 L/min during emergence from anesthesia increased the relative vagal tone, and the arterial blood pressure is stable irrespective of the oxygen flow rate.