Hemodynamic and Bispectral Changes During Pin Insertion in Craniotomy - Effect of Locally Infiltrated Bupivacaine.

Introduction Cranial pins insertion is a method for head stabilization and together with the scalp incision is one of the biggest noxious stimulus associated with arousal and rapid increase of the blood pressure leading to pathological increase of the intracranial pressure. The aim of this investigation is to study the superiority of the locally infiltrated anesthetic bupivacaine just before the skull pin insertion and the scalp incision in craniotomy under general anesthesia. Methods In the study thirty patients of both genders aged 24-72 years were included. They were categorized as ASA 1 and 2 and divided into two group of 15 patients each, group B (bupivacaine) and group S (saline). We recorded the bispectral (BIS) index, the mean arterial pressure (MAP) and the pulse rate (PR) in five time intervals: t 0-2 min before pin insertion; t 1-2 min after pin insertion; t 2-5 min after; t 3-10 min after and t 4-15 min after. Results Significant difference p<0.05 was achieved in group S for all three followed parameters: blood pressure, heart rate and bispectral index. The difference is present in all four time intervals compared to the initial one before the pin insertion. With further analysis it was demonstrated that the investigated BIS index participates the most in the overall significance in group F. Conclusion The scalp infiltration with local anesthetic bupivacaine results with stable hemodynamic parameters and stable intracranial pressure during the painful procedures as craniotomy.

Preemptive analgesic effects of midazolam and diclofenac in rat model.

The aim of the present study was to investigate the preemptive analgesic effects of intraperitoneally administrated midazolam and diclofenac, before acute and inflammatory induced pain in rat model. One hundred twenty-eight (n=8 in each group) male Sprague Dawley rats were included in the study. Paw movements in response to thermal stimulation or paw flinching in response to formalin injection were compared after midazolam (0.1, 1, 5 and 10 mg/kg) and diclofenac (10 mg/kg), intraperitoneal administration. Saline was used as a control. Preemptive analgesic effect was significant in both tests when diclofenac and midazolam was administrated before the pain stimuli (p<0.01 and p<0.001). Intraperitoneal injection of midazolam in doses 5 and 10 mg/kg, increase the response time in hot plate test and decrease the number of flinches in formalin test (p<0.01 vs. p<0.001). ED50 of midazolam (with diclofenac) in hot plate test was 2.02 mg/kg (CI95% =-3.47-5.03 mg); and, 0.9 mg/kg (CI95% =-0.87-4.09 mg) in phase I and 0.7 mg/kg (CI95% = 0.48-6.63 mg) in phase II, in formalin test.Intraperitoneally administered midazolam and diclofenac had preemptive analgesic effects on acute thermal, and inflammatory induced pain in rats.

Preemptive analgesic effect of diclofenac: experimental study in rats.

BACKGROUND: Preemptive analgesia is an antinociceptive treatment that prevents central sensitization. Antinociceptive effects of diclofenac are well-known. The aim of this study was to investigate preemptive analgesic effects of intraperitoneally administrated diclofenac, before and after acute and inflammatory induced pain in rat model. METHODS: Forty eight male Sprague Dawley rats were included in the study. The rats are divided in five groups (n=8 per each group); Group A, diclofenac at 10 mg/kg given ip, 30 min before the nociceptive stimulus realized with hot plate test; Group B, diclofenac at 10 mg/kg given ip, 5 min after the nociceptive stimulus, realized with hot plate test; Group C, diclofenac at 10 mg/kg given ip, 30 min before the nociceptive stimulus realized with formalin test, and; Group D, diclofenac at 10 mg/kg given ip, 5 min after the nociceptive stimulus, realized with formalin test. Saline was used as a control. Paw movements in response to induced pain with hot plate test and formalin test were measured during 60 minutes. RESULTS: Preemptive analgesic effect was significant in both groups when diclofenac was administrated before the pain stimuli (P < 0.01 and P < 0.001). The significant decrease in paw movements started in 15 min after pain stimuli in group A and in 25 min, in group C. CONCLUSION: Intraperitoneally administered diclofenac had preemptive analgesic effects on acute thermal, and inflammatory induced pain in rats. Our results contain the preemptive analgesic effect of systematically administrated diclofenac.