Buffered Versus Nonbuffered Local Anesthetics and Local Pain Scores in Upper Eyelid Blepharoplasty: Randomized Controlled Trial.

PURPOSE: This split-face study aimed to see whether different types of local anesthetics or their buffered/nonbuffered combinations produce lower pain scores in upper eyelid blepharoplasty. METHODS: The study involved 288 patients, randomly divided into 9 groups: 1) 2% lidocaine with epinephrine-Lid + Epi; 2) 2% lidocaine with epinephrine and 0.5% bupivacaine (1:1)-Lid + Epi + Bupi; 3) 2% lidocaine with 0.5% bupivacaine (1:1)-Lid + Bupi; 4) 0.5% bupivacaine-Bupi; 5) 2% lidocaine-Lid; 6) 4% articaine hydrochloride with epinephrine-Art + Epi; 7) buffered 2% lidocaine/epinephrine with sodium bicarbonate (SB) in a 3:1 ratio-Lid + Epi + SB; 8) buffered 2% lidocaine with SB in a 3:1 ratio-Lid + SB; 9) buffered 4% articaine hydrochloride/epinephrine with SB in a 3:1 ratio-Art + Epi + SB. Following the injection of the first eyelid and a 5-minute period of soft pressure on the injection site, patients were asked to rate their pain level on the Wong-Baker Face Pain Rating Visual Analogue Scale. Rating of the pain level was repeated 15 and 30 minutes following anesthetic administration. RESULTS: The lowest pain scores at the first time point were observed in Lid + SB when compared with all of the other groups ( p < 0.05). At the final time point, significantly lower scores were also observed in Lid + SB, Lid + Epi + SB, and Art + Epi + SB when compared with the Lid + Epi group ( p < 0.05). CONCLUSION: These findings could help surgeons select an appropriate combination of local anesthetics, particularly in patients with lower pain threshold and tolerance because buffered combinations of local anesthetics produce significantly lower pain scores compared with nonbuffered solutions.

Evaluation of Prophylactic and Therapeutic Effects of Tramadol and Tramadol Plus Magnesium Sulfate in an Acute Inflammatory Model of Pain and Edema in Rats.

Background: Inflammatory pain is the most commonly treated clinical pain, since it develops following trauma or surgery, and accompanies rheumatic or arthritic diseases. Tramadol is one of the most frequently used opioid analgesics in acute and chronic pain of different origin. Magnesium is a widely used dietary supplement that was recently shown to be a safe analgesic drug in different models of inflammatory pain. Aim: This study aimed to evaluate the effects of systemically or locally injected tramadol with/without systemically injected magnesium sulfate in prophylactic or therapeutic protocols of application in a rat model of somatic inflammation. Methods: Inflammation of the rat hind paw was induced by an intraplantar injection of carrageenan (0.1 ml, 0.5%). The antihyperalgesic/antiedematous effects of tramadol (intraperitoneally or intraplantarly injected), and tramadol-magnesium sulfate (subcutaneously injected) combinations were assessed by measuring the changes in paw withdrawal thresholds or paw volume induced by carrageenan. The drugs were administered before or after inflammation induction. Results: Systemically administered tramadol (1.25-10 mg/kg) before or after induction of inflammation reduced mechanical hyperalgesia and edema with a maximal antihyperalgesic/antiedematous effect of about 40-100%. Locally applied tramadol (0.125 mg/paw) better reduced edema (50-100%) than pain (20-50%) during 24 h. Administration of a fixed dose of tramadol (1.25 mg/kg) with different doses of magnesium led to a dose-dependent enhancement and prolongation of the analgesic effect of tramadol both in prevention and treatment of inflammatory pain. Magnesium increases the antiedematous effect of tramadol in the prevention of inflammatory edema while reducing it in treatment. Conclusion: According to results obtained in this animal model, systemic administration of low doses of tramadol and magnesium sulfate given in combination is a potent, effective and relatively safe therapeutic option for prevention and especially therapy of somatic inflammatory pain. The best result is achieved when tramadol is combined with magnesium sulfate at a dose that is equivalent to the average human recommended daily dose and when the drugs are administered when inflammation is maximally developed.