Remifentanil and Fentanyl in Dental Surgery (REFEDS)

The study included 46 adult patients with cognitive impairment who underwent day-case dental surgery under general anesthesia with propofol aiming to keep a BIS-values range between 40-45. Nasal tracheal intubation was performed in all patients while neuromuscular blockade was achieved by rocuronium 0.6 mg/kg iv and repetitive doses of rocuronium of 10 mg iv, if needed.

Patients were randomly allocated receive for intraoperative analgesia either fentanyl 50 μg iv bolus (group F, n=23) or continuous infusion of remifentanil 0.5-1 μg/kg/min (group R, n=23). Randomization was performed using using a computer-generated randomization schedule.

Intraoperatively, patients in both groups received IV granisetron 3 mg, methylprednisolone 125 mg and clindamycin 600 mg, while atropine 0.02 mg/kg and neostigmine (0.05 mg/kg) was administered to to reverse neuromuscular blockade. Intraoperative monitoring included non-invasive measurement of arterial blood pressure, electrocardiogram, pulse oxymetry, capnography and Bispectral Sedation Index (BIS®).

Postoperatively, patients remained under surveillance in the post-anesthesia care unit [PACU] for 3 h. Postoperative pain was assessed for the first 12 postoperative hours, at 30 min time-intervals for the first 3 hours, and every 3 hours thereafter by an independent observer, blinded to the study group, using the Wong-Baker faces pain rating scale (0-6). If pain scores were ≥3 a rescue dose of paracetamol 12.5 mg/kg iv was administered.

Inflammation markers and stress hormones [cortisol, Tumor necrosis factor (TNF-a), substance-P, melatonin and β-endorphin] were measured in each patient before induction of anesthesia, after tracheal intubation and at the end of operation.

Statistical Analysis was performed using Kolmogorov-Smirnov test, Student's unpaired t-test or Repeated Measures ANOVA with Holm's post-hoc analysis appropriately. A p value less than 0.05 was considered statistically significant.

Inclusion criteria

• Patients with cognitive impairment
• of category II according to the American Society of Anesthesiology (ASA) classification
• scheduled for elective dental surgery with short duration

Exclusion criteria

• Patients of more than category II of American Society of Anesthesiology (ASA) classification
• Prolonged duration of surgery (>1 hour)