Intranasal atomised dexmedetomidine optimises surgical field visualisation with decreased blood loss during endoscopic sinus surgery: a randomized study

Perioperative Low Dose Dexmedetomidine and Its Effect on the Visibility of the Surgical Field for Middle Ear Microsurgery: A Randomised Controlled Trial

Background and Purpose: There are many benefits of administering dexmedetomidine perioperatively. The pharmacokinetics (PK) and pharmacodynamics (PD) of intravenous, intranasal and oral dexmedetomidine that was administered before anesthesia were compared in this study, and the effects of dexmedetomidine on the surgical field visibility in tympanoplasty was evaluated. Methods: A single-blind, randomized controlled trial was conducted in a university-affiliated hospital where 45 patients who underwent tympanoplasty under general anesthesia were randomly allocated into three groups. Dexmedetomidine was administered by intravenous infusion at 0.8 μg.kg^-1 for 10 min, intranasal instillation at a drop rate of 1 μg.kg^-1 and oral intake at 4 μg.kg^-1 ten minutes before the induction of anesthesia. The PK and PD of dexmedetomidine after a single low dose administration and its effect on the surgical field in tympanoplasty were analysed. Results: A plasma concentration of dexmedetomidine of 220 pg/ml was achieved immediately after intravenous infusion and at 13.2 and 70.3 min for intranasal and oral administration, respectively. Dexmedetomidine decreased the heart rate (HR) and mean arterial pressure (MAP) in all three groups, although these values remained higher in the oral dexmedetomidine group at all eight time points. Intravenous dexmedetomidine provided the best visualization of the surgical field for opening of the tympanic sinus, 30 min after the start of the infusion (p < 0.05). Intranasal dexmedetomidine provided a significantly better visual field than oral dexmedetomidine for the repair of a tympanic membrane perforation using the fascia temporal muscle (p < 0.05). Conclusion: A single low dose of dexmedetomidine administered intravenously or intranasally could decrease HR and MAP, improve surgical field visibility and be appropriate for deliberate hypotension for surgical procedures of 1-2 h in length. Trial registration: Clinicaltrials.gov identifier: NCT03800641.

Validation of the Modena bleeding score in endoscopic sinus surgery

Introduction

The Modena bleeding score is a categorical rating scale that allows the assessment of the surgical field in relation to bleeding during endoscopic surgery. It has recently been presented and validated in the field of endoscopic ear surgery by the present authors. The Modena bleeding score provides five grades for rating the surgical field during endoscopic procedures (from grade 1 − no bleeding to grade 5 − bleeding that prevents every surgical procedure except those dedicated to bleeding control).

Objective

The aim of this study was to validate the Modena bleeding score in the setting of endoscopic sinus surgery.

Methods

Fifteen three-minute videos of endoscopic sinus surgery procedures (each containing three bleeding situations) were evaluated by 15 specialists, using the Modena bleeding score. Intra and inter-rater reliability were assessed, and the clinical validity of the Modena bleeding score was calculated using a referent standard.

Results

The data analysis showed an intra-rater reliability ranging from 0.6336 to 0.861. The inter-rater reliability ranged from 0.676 to 0.844. The clinical validity was α = 0.70; confidence limits: 0.64 − 0.75, corresponding to substantial agreement.

Conclusion

The Modena bleeding score is an effective method to score bleeding during endoscopic sinus surgery. Its application in future research could facilitate the performance and efficacy assessment of surgical techniques, materials or devices aimed to bleeding control during endoscopic sinus surgery.

Intranasal Low-Dose Dexmedetomidine Reduces Postoperative Opioid Requirement in Patients Undergoing Hip Arthroplasty Under General Anesthesia

BACKGROUND

Patients undergoing total hip arthroplasty (THA) need substantial amount of opioids for postoperative pain management, which necessitates opioid-sparing modalities. Dexmedetomidine is a novel alpha-2-adrenoceptor-activating drug for procedural sedation. In addition to its sedative effect, dexmedetomidine has analgesic and antiemetic effects. We evaluated retrospectively the effect of intraoperatively administered intranasal low-dose dexmedetomidine on postoperative opioid requirement in patients undergoing THA.

METHODS

We included 120 patients with American Society of Anesthesiologists status 1-2, age between 35 and 80 years, and scheduled for unilateral primary THA under general anesthesia with total intravenous anesthesia. Half of the patients received 50 μg of intranasal dexmedetomidine after anesthesia induction, while the rest were treated conventionally. Postoperative opioid requirements were calculated as morphine equivalent doses for both groups. The impact of intranasal dexmedetomidine on postoperative hemodynamics and length of stay was evaluated.

RESULTS

The cumulative postoperative opioid requirement was significantly reduced in the dexmedetomidine group compared with the control group (26.3 mg, 95% confidence interval 15.6-36.4, P < .001). The cumulative dose was significantly different between the groups already at 12, 24, and 36 h postoperatively (P = .01; P = .001; P < .001, respectively). Dexmedetomidine group had lower mean arterial pressure in the postanesthesia care unit compared with the control group (P = .01). There was no difference in the postanesthesia care unit stay or postoperative length of stay between the two groups (P = .47; P = .10, respectively).

CONCLUSION

Compared with the control group, intraoperative use of intranasal low-dose dexmedetomidine decreases opioid consumption and sympathetic response during acute postoperative period in patients undergoing THA.

Anesthesia for functional endoscopic sinus surgery

PURPOSE OF REVIEW

The present article summarizes anesthetic techniques used during functional endoscopic sinus surgery to decrease bleeding and aid in creating a clear surgical field. The applicable physiology behind these anesthetic techniques is reviewed with emphasis on the effect on bleeding and the surgical field. Deliberate hypotension, reverse Trendelenburg positioning, regional anesthesia, and cerebral monitoring are discussed.

RECENT FINDINGS

There are mixed data as to whether traditional inhalation anesthesia or total intravenous anesthesia is superior with respect to better surgical fields and decreased blood loss. A review of the literature tends to favor total intravenous anesthesia. Cerebral oximetry and transcranial Doppler ultrasound are emerging techniques to monitor cerebral perfusion during deliberate hypotension.

SUMMARY

Total intravenous anesthesia using propofol and remifentanil is the current favored technique for producing deliberate hypotension during endoscopic sinus surgery due to its hemodynamic stability and smooth rapid emergence.