Efficacy of ultrasound-guided Transversus Abdominis Plane (TAP) block in inguinal hernia surgery and the immunomodulatory effects of proinflammatory cytokines: prospective, randomized, placebo-controlled study.

BACKGROUND: Tumor Necrosis Factor-α (TNF-α) and Interleukin-1ß (IL-1ß) are among the cytokines released secondary to the surgical stress response. The objective of this study was to investigate the effect of a Transversus Abdominis Plane (TAP) block on postoperative pain and its immunomodulatory activity through proinflammatory cytokines. METHODS: TAP (study group; n=40) or p-TAP (placebo group; n=40). Patients in the TAP group underwent an Ultrasound (US) guided unilateral TAP block using 20-cc 0.5% bupivacaine solution. Patients in the p-TAP group underwent a sham block using 20-cc isotonic solution. The TNF-α and IL-1ß levels were measured three times at preoperative hour-0 and postoperative hours 4 and 24. Visual Analog Scale (VAS) scores were recorded at 0-hours, 30-minutes, 4-hours, and 24-hours. Analgesic use within the first 24-hours following surgery was monitored. RESULTS: The postoperative VAS score was decreased in the TAP group at all time points (0, 4, and 24hours), and the differences between groups were statistically significant (p< 0.001 for all comparisons). In the TAP group, the TNF-α and IL-1ß levels at 4 and 24 hours post operation were significantly lower than the preoperative levels (p< 0.001 for all comparisons). CONCLUSION: The TAP block for pre-emptive analgesia enabled effective hemodynamic control during the intraoperative period, provided effective pain control in the postoperative period, and decreased inflammation and surgical stress due to the decreased levels of the proinflammatory cytokines TNF-α and IL-1ß in the first postoperative 24hours, indicating immunomodulatory effect.

Histopathologic comparison of dexmedetomidine's and thiopental's cerebral protective effects on focal cerebral ischemia in rats.

This study was designed to investigate whether dexmedetomidine and thiopental have cerebral protective effects after focal cerebral ischemia in rats. Thirty male Sprague Dawley rats were randomly assigned to three groups: control group (Group C, n=10), dexmedetomidine group (Group D, n=10), thiopental group (Group T, n=10). After all rats were anesthetized, they were intubated, then mechanically ventilated. A catheter was inserted into the right femoral artery for continuous mean arterial pressure, physiological parameters and blood sampling at baseline, 5min after occlusion and 20min after reperfusion. A catheter was inserted into the left femoral vein for intravenous (IV) medication administration. Right common carotid artery of each rat was isolated and clamped for 45min. At the end of the duration common carotid artery were unclamped and the brain reperfusion was achieved for 90min. Dexmedetomidine was administered for Group D IV infusion, and Group T received thiopental IV. According to histopathologic scores cerebral ischemia was documented in all rats in Group C, but no ischemia was found in three rats in Group T and in four rats in Group D. Grade 3 cerebral ischemia was documented in three rats in Group C, and in only one rat in both groups T and D. For histopathologic grades the difference between Group T and Group D was not significant (p>0.05). But the differences between Group C and Group T (p<0.05) and Group C and Group D (p<0.01) were statically significant. In conclusion, we demonstrated that dexmedetomidine and thiopental have experimental histopathologic cerebral protective effects on experimental focal cerebral ischemia in rats.

[Histopathologic comparison of dexmedetomidine's and thiopental's cerebral protective effects on focal cerebral ischemia in rats]. / Comparação histopatológica dos efeitos protetores cerebrais de dexmedetomidina e tiopental sobre isquemia cerebral focal em ratos.

This study was designed to investigate whether dexmedetomidine and thiopental have cerebral protective effects after focal cerebral ischemia in rats. Thirty male Sprague Dawley rats were randomly assigned to three groups: control group (Group C, n=10), dexmedetomidine group (Group D, n=10), thiopental group (Group T, n=10). After all rats were anesthetized, they were intubated, then mechanically ventilated. A catheter was inserted into the right femoral artery for continuous mean arterial pressure, physiological parameters and blood sampling at baseline, 5min after occlusion and 20min after reperfusion. A catheter was inserted into the left femoral vein for intravenous (IV) medication administration. Right common carotid artery of each rat was isolated and clamped for 45min. At the end of the duration common carotid artery were unclamped and the brain reperfusion was achieved for 90min. Dexmedetomidine was administered for Group D IV infusion, and Group T received thiopental IV. According to histopathologic scores cerebral ischemia was documented in all rats in Group C, but no ischemia was found in three rats in Group T and in four rats in Group D. Grade 3 cerebral ischemia was documented in three rats in Group C, and in only one rat in both groups T and D. For histopathologic grades the difference between Group T and Group D was not significant (p>0.05). But the differences between Group C and Group T (p<0.05) and Group C and Group D (p<0.01) were statically significant. In conclusion, we demonstrated that dexmedetomidine and thiopental have experimental histopathologic cerebral protective effects on experimental focal cerebral ischemia in rats.