DEXMEDETOMIDINE USE IN DIRECT LARYNGOSCOPIC BIOPSY UNDER TIVA AYSE MIZRAK*, MARUF SANLI**, SEMSETTIN BOZGEYIK*, RAUF GUL*, SULEYmaN GANIDAGLI*, ELIF BAYSAL*** AND UNSAL ONER* Abstract Background: The purpose of this study is to investigate the suitability of dexmedetomidine as a helpful sedative agent in direct laryngoscopic biopsy (DLB), under total intravenous anesthesia (TIVA). Methods: In this double blind randomised study, patients were allocated to receive dexmedetomidine 0.5 µg/kg (group D, n = 20) or saline placebo (group P, n = 20) intravenously. Forty ASA I-III patients were infused propofol and administered rocuronium bromur. They were intubated and performed biopsy. Aldrete scores, intraoperative propofol and postoperative analgesic requirements, satisfaction scores, recovery time, Ramsay sedation scale (RSS), haemodynamic changes and side effects were recorded. Results: Postoperative analgesic requirement in group D was significantly lower and satisfaction scores and RSS were significantly higher than in group P. Additionally, MAP (mean arterial blood pressure) significantly decreased at post-extubation time in group D. Conclusion: The premedication with a single dose of dexmedetomidine decreases intraoperative propofol and postoperative analgesic requirements, increases the postoperative satisfaction and RSS considerably in patients undergoing DLB under TIVA. Key words: Direct laryngoscopic biopsy (DLB), airway reflexes, dexmedetomidine, laryngeal tumor, TIVA (Total Intravenous Anesthesia). Financial Source which supports work: There is no conflict of interest: disclosure of any financial relationships between authors and commercial interests with a vested interest in the outcome of the study. * Anesthesiology and Reanimation, Gaziantep University School of Medicine Gaziantep/TURKEY. ** Thoracic Surgery, Gaziantep University School of Medicine Gaziantep/TURKEY. *** Ear Nose and Throat (ENT), Gaziantep University School of Medicine Gaziantep/TURKEY. Corresponding author: Dr. Ayse Mizrak, Gaziantep University Medical Faculty, Department of Anesthesiology and Reanimation, 27310 Sahinbey, Gaziantep, TURKEY, E- mail: [email protected], Fax: 00903423602244, Tel: 00905337181025. 605 M.E.J. ANESTH 21 (4), 2012 606 A. MIZRAK EY AL. Introduction effects of DLB and benefit from these desirable effects, we preferred to use dexmedetomidine in the present The incidence of laryngeal CA is about 1% of study. all cancers. Squamous cell CA’s are the most common laryngeal tumors in our patient population. Laryngeal Thus, we aimed to investigate the effect of tumors also include papillomas, cysts in the glottic low dose of dexmedetomidine on airway reflexes, area1. Before the anesthetic management of these haemodynamics, patient comfort, sedation, and patients, preoperative examination and evaluation by intraoperative anesthetic and postoperative analgesic the ear, nose, and throat (ENT) surgeons are essential2. requirements during and after DLB. If the patient has difficulty opening the mouth, mallampati class is higher than grade 2 and airway Methods categories are higher than grade 2b, generally, the next A. Selection and description of participants: procedure is to proceed with fiberoptic intubation or The study group comprised 40 ASA I-III patients, tracheostomy. There are several advantages of DLB, aged 32-67 years. All participants were scheduled to along with a number of detrimental effects. Patients undergo direct laryngoscopy and biopsy under TIVA. with laryngeal tumors can present a challenge to All procedures were performed by the same surgeon. guarantee the airway for laryngeal biopsy. During DLB, The work presented was performed in accordance with there may be acute changes in systemic and pulmonary the most recent version of the Helsinki Declaration. haemodynamics, together with blood gas changes such as increase in heart rate, blood pressure, airway Following approval from the institutional review and circulatory reflexes during surgical procedure3. board, written informed consent was obtained from all participants. Dexmedetomidine, an α-2 agonist, has none to minimal respiratory depressant effects, which is clearly a great All patients were in part of grade 1, which includes advantage in handling a critical airway while inducing patients with fully visible vocal folds, grade 2a, which sedation. Further, dexmedetomidine has anxiolytic, includes patients with clearly visible vocal folds with antisialagogue4 and moderate analgesic5 effects. It was small or medium size tumors not obstructing the view demonstrated to be a useful agent for sedation during of glottis, or grade 2b in which only parts of vocal awake fiberoptic intubation in difficult airways6. folds are partly visible and large tumors involve 1 or Furthermore dexmedetomidine was demonstrated to both vocal folds. The evaluation was carried out by the attenuate the increase in heart rate and arterial blood ear, nose, and throat (ENT) surgeon by means of the pressure during intubation7 and was shown to attenuate preoperative indirect laryngoscopy. The patients with the airway and circulatory reflexes during extubation difficulty opening the mouth, Mallampati class higher in ocular surgery8. Our patients consisted of more than 2, airway categories higher than grade 2b (grade 3, frequently elderly, ASA I-III patients who may have grade 4), or ischemic heart disease, heart blocks, the use some latent respiratory and cardiovascular disease. of premedication drugs such as β adrenergic blockers, Jorden et al.9 concluded that, an accidental overdose and tricyclic antidepressant drugs, and a known or a in the perioperative setting with the administration family history of reactions to dexmedetomidine HCl of dexmedetomidine up to 0.5 µg/kg/min produced (Precedex®, Abbott, North Chicago, IL, USA) or excessive sedation but stable haemodynamics. propofol (Propofol, 1%, Fresenius Kabi AB, Sweden) As, DLB is a rather shortly procedure, it also were excluded. needs a short time for general anesthesia. Therefore B. Technical information: Patients were the action time of the induction and sedative agents assigned to one of two study groups using a computer should be short with minimum respiratory side effects. generated random number table. After the patients Propofol may be the ideal agent with these objectives had been taken to surgery room, standard monitors for DLB. So far, no drug has been proposed for the including electrocardiography, non invasive blood attenuation of cardiovascular and airway responses pressure (MAP) measurement and pulse oximetry were during DLB under TIVA. To avoid the detrimental used throughout the procedure (Monitor; Siemens DEXMEDETOMIDINE USE IN DIRECT LARYNGOSCOPIC BIOPSY UNDER TIVA 607 SC 7000, Sweden). No patient was premedicated of Ramsay; 1 = Anxiety and completely awake, 2 = with another drug. The study medication consisted Completely awake, 3 = Awake but drowsy, 4 = Asleep of dexmedetomidine (0.5 µg/kg) or normal saline in but responsive to verbal commands, 5 = Asleep but a total volume of 20 mL, which was prepared by an responsive to tactile stimulus, and 6 = Asleep and not anesthesiologist not involved to measurements and responsive to any stimulus. Postoperative analgesic evaluation, and was infused intravenously in 10 minutes (Diclomec, Diklofenak Sodyum, 75 mg/3 ml, amp, before induction of anesthesia. After premedication Topkapı Istanbul) requirement was ascertained during with the study drugs, fentanyl 1 µg/kg and propofol postoperative 24-hour-period. were administered slowly (20 mg/10 sec) until the loss All the evaluations were performed by a blinded of eyelash reflex or the patient no longer responded to observer who was different from the person who had his name being called loudly. Propofol was continued to performed the premedication. Pre-intra- postoperative be given at a rate of 6 mg/kg/hour, followed by fentanyl hypertension, hypotension, bradycardia, tachycardia, (Fentanyl citrate, B. Braun Melsungen AG, Berlin, nausea, vomiting, coughing, straining, dizziness, Germany) 1 µg/kg and rocuronium bromur (Esmeron, respiratory depression (defined as a respiratory rate Organon, Oss Holland) 0.6 mg/kg because of the short <10 breaths/min), hypoxemia (defined as SPO2 duration of the procedure. Tracheal intubation with ≤90%, tachycardia (HR >100 beat/min), bradycardia Miller blade (2-4 sizes) was attempted to expose the (HR <50 beat/min), hypotension (MAP <60 mmHg), glottis for intubation using a polyvinyl tracheal tube of hypertension (MAP >120 mmHg) were noted if present 5.5 to 6 mm ID in patients with grade 1, grade 2a and at 30 and 60 min in the preoperative and postoperative grade 2b. Ventilation was assisted with 70% oxygen period. and 30% air without inhalation anesthetic. At the end C. Statistics: Data are presented as mean ± SD of the procedure, muscle relaxant effects were reversed and median (interquartile ranges) values, and statistical using neostigmine and atropine and all patients were significance was reported when the p value was <0.05. given oxygen after the operations. Between-groups, differences were evaluated by means When the patients were awake and cooperative, of Mann Whitney-U test. Friedman and Wilcoxon tracheal extubation was accomplished in the sign tests were applied to evaluate the differences post anesthesia care unit. Intraoperative propofol between repeated values in the groups. Data were requirement, Aldrete score, and recovery time were presented as means ± SD. All data were analyzed