Integrative review utilizing dexmedetomidine as an anesthetic for monitored anesthesia care and regional anesthesia

Dexmedetomidine-remifentanil vs propofol-remifentanil for monitored anesthesia care during hysteroscopy: Randomized, single-blind, controlled trial

BACKGROUND

Although dexmedetomidine has been used as either the anesthetic agent for light sedation or as an adjunct to other sedatives, no study has investigated the usefulness of dexmedetomidine as the main sedative agent for invasive and painful procedures. The purpose of this study was to compare the safety of dexmedetomidine-remifentanil and propofol-remifentanil during monitored anesthesia care (MAC) for hysteroscopy.

METHODS

Female patients undergoing hysteroscopy were randomly assigned to either the dexmedetomidine (group D) or the propofol group (group P). The study drug (0.6 ml/kg; dexmedetomidine 2 μg/ml or propofol 4 mg/ml) was loaded for 10 minutes followed by 0.1 to 0.5 ml/kg/hour to maintain a bispectral index of 60 to 80 during the procedure. In both groups, remifentanil was infused using a target-controlled-infusion system with a target concentration of 2 ng/ml and titrated during the procedure. The incidence rates of intraoperative respiratory depression in both groups were compared. Postoperative pain and patients satisfaction were also compared.

RESULTS

A total of 69 female patients were included in this study. Dexmedetomidine significantly decrease the incidence of respiratory depression compared with propofol (15/34 [44.1%] vs 5/35 [14.3%], P = .006, group P and D, respectively). Postoperative pain and patients satisfaction score did not differ between the groups.

CONCLUSION

The combination of dexmedetomidine-remifentanil can reduce the incidence of respiratory depression without increasing hemodynamic complications compared with propofol-remifentanil for MAC during hysteroscopy.

Beneficial effects of dexmedetomidine on early postoperative cognitive dysfunction in pediatric patients with tonsillectomy

According to clinical investigations, early postoperative cognitive dysfunction is the most common adverse event in pediatric patients after tonsillectomy. A previous study has indicated that dexmedetomidine (DEX) is an efficient drug for the treatment of postoperative cognitive dysfunction. However, the efficacy of DEX in alleviating early postoperative cognitive dysfunction in pediatric patients following tonsillectomy has remained elusive, which was therefore assessed in the present study. A total of 186 children presenting with cognitive dysfunction subsequent to tonsillectomy were recruited to analyze the efficacy of DEX. Patients were randomly divided into two groups and received intravenous treatment with DEX (n=112) or placebo (n=74). Duration of treatment, dose-limiting toxicities (DLT) and maximum tolerated dose (MTD) of DEX were evaluated in a preliminary experiment. The improvement of postoperative cognitive function in children with tonsillectomy was analyzed with a Mini-Mental State Examination (MMSE) following treatment with DEX. A 40-item quality of life (MONEX-40) questionnaire was used to assess the efficacy of DEX. The plasma levels of interleukin (IL)-6, IL-1, tumor necrosis factor (TNF)-α, superoxide dismutase (SOD), neuron-specific enolase (NSE), C-reactive protein (CRP), cortisol and melatonin were also analyzed. The preliminary experiment determined that the DLT was 10 mg/kg and the MTD was 15 mg/kg. In the major clinical trial, it was revealed that MMSE scores in the DEX treatment group were markedly improved, indicating that DEX had a beneficial effect in pediatric patients with early postoperative cognitive dysfunction after tonsillectomy. In addition, IL-1and TNF-α were downregulated, while IL-6 and SOD were upregulated in patients with cognitive dysfunction after treatment with DEX compared with those in the placebo group. Furthermore, DEX treatment markedly decreased the serum levels of CRP, NSE cortisol and melatonin, which are associated with the occurrence of postoperative cognitive dysfunction in pediatric patients following tonsillectomy. In conclusion, intravenous administration of DEX at a dose of 10 mg/kg improves postoperative cognitive function in pediatric patients with tonsillectomy by decreasing the serum levels of inflammatory factors and stress-associated signaling molecules. Trial registration no. QLSDHOS0200810102C (Qilu Hospital of Shandong University, Jinan, China).

Intranasal Dexmedetomidine on Stress Hormones, Inflammatory Markers, and Postoperative Analgesia after Functional Endoscopic Sinus Surgery

Background. A strong ongoing intraoperative stress response can cause serious adverse reactions and affect the postoperative outcome. This study evaluated the effect of intranasally administered dexmedetomidine (DEX) in combination with local anesthesia (LA) on the relief of stress and the inflammatory response during functional endoscopic sinus surgery (FESS). Methods. Sixty patients undergoing FESS were randomly allocated to receive either intranasal DEX (DEX group) or intranasal saline (Placebo group) 1 h before surgery. Stress hormones, inflammatory markers, postoperative pain relief, hemodynamic variables, blood loss, surgical field quality, body movements, and satisfaction were assessed. Results. Plasma epinephrine, norepinephrine, and blood glucose levels were significantly lower in DEX group as were the plasma IL-6 and TNF-α levels (P < 0.05). The weighted areas under the curve (AUCw) of the VAS scores were also significantly lower in DEX group at 2–12 h after surgery (P < 0.001). Furthermore, hemodynamic variables, blood loss, body movements, discomfort with hemostatic stuffing, surgical field quality, and satisfaction scores of patients and surgeons were significantly better (P < 0.05) in DEX group. Conclusions. Patients receiving intranasal DEX with LA for FESS exhibited less perioperative stress and inflammatory response as well as better postoperative comfort with hemostatic stuffing and analgesia.