RESUMO
BACKGROUND: The pupillary dilation reflex (PDR) is an objective indicator of analgesic levels in anesthetized patients. Through measurement of the PDR during increasing tetanic stimulation (10-60 mA), it is possible to obtain the pupillary pain index (PPI), a score that assesses the level of analgesia. OBJECTIVES: The depth of analgesia during opioid-sparing anesthesia (OSA) with continuous infusion of dexmedetomidine in addition to general anesthesia was assessed. DESIGN: Observational prospective feasibility pilot study SETTING: This study was performed in the operating rooms of the Spedali Civili University-affiliated hospital of Brescia, Italy. PATIENTS: Forty-five adults who underwent elective open (5-cm incision) surgery under general anesthesia (78% inhalation anesthesia), from Feb. 18th to Aug. 1st, 2019, were enrolled. Exclusion criteria were as follows: implanted pacemaker or ICD, ophthalmological comorbidities, chronic opioid use, peripheral neuropathy, other adjuvant drugs, epidural analgesia, or locoregional block. MAIN OUTCOME MEASURES: The first aim was to verify the feasibility of applying a study protocol to evaluate the depth of analgesia during intraoperative dexmedetomidine administration using an instrumental pupillary evaluation. The secondary outcome was to evaluate appropriate analgesia, drug dosage, anesthesia depth, heart rate, blood pressure, transient side effects, postoperative nausea and vomiting (PONV), and pain numerical rating scale (NRS) score. RESULTS: Thirty out of 50 patients (60%) treated with dexmedetomidine during the study period were included in the DEX group (8 males, age 42 ± 13 years, BMI 45 ± 8), and 15 other patients were included in the N-DEX group (8 males, age 62 ± 13 years, BMI 26 ± 6). Patients who underwent bariatric, abdominal, or plastic surgery were enrolled. At least 3 pupillary evaluations were taken for each patient. PPI ≤ 3 was observed in 97% of patients in the DEX group and 53% in the N-DEX group. Additionally, the DEX group received less than half the remifentanil dose than the N-DEX group (0.13 ± 0.07 vs 0.3 ± 0.11 mcg kg-1 min-1). The average dose of dexmedetomidine administered was 0.17 ± 0.08 mcg kg-1 h-1. CONCLUSION: The feasibility of applying the protocol was verified. An OSA strategy involving dexmedetomidine may be associated with improved analgesic stability: a randomized controlled trial is necessary to verify this hypothesis. TRIAL REGISTRATION: Trial.gov registration number: NCT05785273.
RESUMO
BACKGROUND: Unpredicted Difficult Tracheal Intubation (DTI) with Macintosh occurs frequently in obese patients. We investigated the incidence of DTI using an algorithm based on preoperative assessment with the El-Ganzouri Risk Index (EGRI) and Glidescope® routine use. METHODS: We prospectively enrolled morbidly obese patients undergoing abdominal surgery. Patients were scheduled for Glidescope® intubation under general anesthesia if EGRI was <7 or awake Flexible Fiber-optic Intubation if EGRI was ≥7. The primary outcome was the DTI rate, defined as Cormack and Lehane grades ≥III, Intubation Difficulty Scale >5 and modified Intubation Difficulty Scale >5. Secondary outcomes included intubation success on the first attempt, the Time to Cormack, the time to intubation, failure to intubate, oxygen desaturation and difficult ventilation. RESULTS: Of the 214 patients enrolled, 212 (99%) were intubated with Glidescope® and 2 (1%) with awake Flexible Fiber-optic Intubation (one electively, one after a Glidescope® failure). There were no cases of DTI assessed using Cormack and Lehane and Intubation Difficulty Scale, and 3 cases (1.4%; 95% CI 0.45-4.29%) assessed using modified Intubation Difficulty Scale. Of the 213 patients intubated with Glidescope®, 185 (87%) had successful intubation on the first attempt. Mean Time to Cormack and time to intubation were 13.1 (SD 9.6) and 38.1 seconds (SD 21.1) respectively. We had one case (0.5%) of failed Glidescope® intubation and no cases of clinically significant complications. CONCLUSIONS: The incidence of DTI and Intubation Failure was reduced to near-zero using Glidescope® and the Besta Airway Algorithm in this sample of morbidly obese patients.