Comparison of an intraoperative infusion of dexmedetomidine or fentanyl for the perioperative hemodynamics, achieving hypnosis and sedation, and the postoperative pain control

BACKGROUND: The aim of this study was to compare dexmedetomidine (DEX), which is a selective, short-acting, central alpha2-adrenergic agonist, with fentanyl in terms of the hemodynamic stability, achieving hypnosis and sedation, and the postoperative pain control at the PACU (postanesthetic care unit). METHODS: In this double-blind study, 50 consecutive total laparoscopic hysterectomy patients scheduled for elective surgery were randomly assigned to receive either dexmedetomidine 1 microg/kg over 10 min followed by a 0.5 microg/kg/hr infusion (the DK group) or fentanyl 0.8-1.2 microg/kg over 1 min followed by a 0.2-0.6 microg/kg/hr infusion (the FK group) from the time of ending the operation after total hysterectomy to the time in the PACU. We evaluated the pain VAS scores, the modified OAA/S scores, the BIS, the vital signs, the respiratory variables (SpO2, RR and EtCO2) and the perioperative side effects to compare the efficacy of dexmedetomidine and fentanyl. RESULTS: Compared with the fentanyl-ketorolac (FK) group, the modified OAA/S scores were significantly lower in the dexmedetomine-ketorolac (DK) group at 0, 5 and 10 min after arrival at the PACU (P < 0.05), whereas the pain VAS and BIS were not significantly different between the two groups. The blood pressure and heart rate in the DK group was significantly lower than that of the FK group at the PACU (P < 0.05). CONCLUSIONS: The DK group, at the doses used in this study, has a significant advantage over the FK group in terms of the postoperative hemodynamic stability at the PACU. There was no significant difference between the two groups for the postoperative pain control.

Comparison of an intraoperative infusion of dexmedetomidine or fentanyl for the perioperative hemodynamics, achieving hypnosis and sedation, and the postoperative pain control

BACKGROUND: The aim of this study was to compare dexmedetomidine (DEX), which is a selective, short-acting, central alpha2-adrenergic agonist, with fentanyl in terms of the hemodynamic stability, achieving hypnosis and sedation, and the postoperative pain control at the PACU (postanesthetic care unit). METHODS: In this double-blind study, 50 consecutive total laparoscopic hysterectomy patients scheduled for elective surgery were randomly assigned to receive either dexmedetomidine 1 microg/kg over 10 min followed by a 0.5 microg/kg/hr infusion (the DK group) or fentanyl 0.8-1.2 microg/kg over 1 min followed by a 0.2-0.6 microg/kg/hr infusion (the FK group) from the time of ending the operation after total hysterectomy to the time in the PACU. We evaluated the pain VAS scores, the modified OAA/S scores, the BIS, the vital signs, the respiratory variables (SpO2, RR and EtCO2) and the perioperative side effects to compare the efficacy of dexmedetomidine and fentanyl. RESULTS: Compared with the fentanyl-ketorolac (FK) group, the modified OAA/S scores were significantly lower in the dexmedetomine-ketorolac (DK) group at 0, 5 and 10 min after arrival at the PACU (P < 0.05), whereas the pain VAS and BIS were not significantly different between the two groups. The blood pressure and heart rate in the DK group was significantly lower than that of the FK group at the PACU (P < 0.05). CONCLUSIONS: The DK group, at the doses used in this study, has a significant advantage over the FK group in terms of the postoperative hemodynamic stability at the PACU. There was no significant difference between the two groups for the postoperative pain control.

The Effects of Glucocorticoid and alpha-Lipoic Acid on Ischemia-Reperfusion Injury

During revascularization after ischemia, oxygen free radicals and cytotoxic enzymes are released and they have a role in pathogenesis of ischemia-reperfusion injury. Glucocorticoid decreases oxygen free radical formation by inhibition of arachidonic acid metabolism, and alpha-lipoic acid scavenges nitric oxide(NO) with inhibition of hydroxy radical formation. Author investigated the role of glucocorticoid and alpha-lipoic acid to decrease ischemia reperfusion injury in 24 anesthetized rats (normal saline-injected, n= 8; dexamethasone-injected, n=8; alpha-lipoic acid-injected, n= 8), subjecting a soleus muscle to 4 hours of tourniquet ischemia followed by 2 hours of reperfusion, and evaluated the concentration of NO, tissue edema, and neutrophil count of rat skeletal muscle as a indicator of tissue damage by ischemia- reperfusion injury. We obtained the results that glucocorticoid and alpha-lipoic acid treatment decreased the increase of NO concentration, tissue edema, and neutrophil count significantly. These results support that pretreatment with glucocorticoid or alpha-lipoic acid has a beneficial effect on the preventive management of ischemia-reperfusion injury.

Comparative Studies on the Effects of Experimental Cryopexy and Diathermy Coagulation on Rabbits ERG

Twelve albino rabbits were treated with cryoretinopexy on the left eye and surface diathermy coagulation on the right eye at the equatorial region in two parallel rows concentric with the limbus. Cryopexy was applied for 10 seconds with Krwawicz's probe (the diameter of the tip was 1.5 mm) after cooling with dry ice and alcohol mixture. Diathermy coagulation was performed with 40 mA currents for 2 seconds with needle electrode without perforating the sclera. After the treatment, ERG was recorded with varying length of intervals up to 30 days. The light stimulus was given by 100 watts incadenscent lamp and the illumination at the eye was 800 lux, its duration being 20 msec. Only the sizes of the b-potentials after 30 minutes of dark adaptation were considered. The patterns of the b-potential changes after cryopexy were roughly divided into 3 types. The first type was seen in 5 eyes, and it consisted of abrupt reductions, followed by slight augmentations, never reaching the pre-treatment level of b-wave even after 30 days. The second type (seen in 3 eyes) showed initial slight decreases followed by marked increases and remained supernormal at the end of 30 days. The third type(4 eyes) showed marked increases from the early post-operative days and returned to the original level after 30 days. These changes were demonstrated graphically in figures 3, 4 and 5. By diathermy coagulation, the same kinds of patterns were observed. The same animal, however, did not show the same pattern as with the cryopexy. The final b-potential after 30 days were 105.4% of the pre-operative value by cryopexy and 82.7% by diathermy coagulation. Thus the cryopexy produced less severe changes in ocular tissues than the diathermy coagulation. The histological observations performed also supported this conclusion.