A comparative study of the effect of dexamethasone versus its use with clonidine on postoperative sore throat and hoarseness of voice

Abstract

Regardless of some preventive measures, postoperative sore throat (POST) and hoarseness of voice are most undesirable and most frequent complication in the post-operative period [1,2]. Postoperatively it seems reasonable that most of the signs and symptoms are the result of mucosal injury which leads to inflammation caused by the process of air way instrumentation, also its postulated etiology has been associated with mucosal dehydration or edema, tracheal ischemia secondary to the pressure of endotracheal tube cuffs, aggressive oropharyngeal suctioning and mucosal erosion from friction between delicate tissues and the endotracheal tube (ETT) [4,5]. Aim, the primary outcome was to compare between the effects of Dexamethasone alone versus its use with Clonidine on post-operative sore throat. The secondary outcome was to compare between the effects of Dexamethasone alone versus its use with Clonidine on post-operative hoarseness of voice. Method, this prospective controlled randomized double- blind study was carried on 126 patients divided into two groups the Dexa group 63 and Dexaclonidine group 63. Randomization were done by using closed envelop technique opened immediately before induction by an anaesthetist who was unaware of the study protocol and responsible for preparing the study drugs. Patient in Dexaclonidine group received oral 150 microgram Clonidine tablet one hour before induction, whereas patients in the Dexa group received placebo which is multivitamin tablet with the same shape and size of Clonidine. Both Clonidine and placebo were covered with nontransparent paper. Patients in both groups were received 5 ml of normal saline containing Dexamethasone (8 mg) iv at 30 min before anaesthetic induction. Sedation with midazolam was given (0.05 mg/kg) IV 15 minutes before surgery for the two groups. On arrival to operating room patients were cannulated and monitored with electrocardiography, non-invasive blood pressure, pulse oximetry and capnography. Anaesthesia was induced with intravenous propofol (2 mg/kg) and fentanyl (1–1.5 micro g/kg) after approximately 5 min of preoxygenation and face mask ventilation. Rocuronium (0.6–0.8 mg/ kg) was administered to facilitate endotracheal intubation after using of nerve stimulator (train of four) to ensure complete muscle relaxation before intubation, an endotracheal tube were inserted (ETTs) after Cormack-Lehane scoring (13) of internal diameter 7.0 and 7.5 were used for females and males, respectively by Direct laryngoscopy with either a Macintosh blade size 3 or 4. The ETTs were inserted so that the vocal cords were located between the two indicator marks on the proximal part of the tube shaft. Intubations were confirmed by capnography and chest auscultation for equality of air entry on both sides. None of the patients received topical lidocaine or lidocaine jelly during the intubation procedure. The lungs were ventilated with 50% air 50% oxygen; ventilation was adjusted to maintain an end tidal carbon dioxide of 35–45 mmHg. Anaesthesia was maintained with isoflurane and intermittent bolus dose of rocuronium. Isoflurane concentration was adjusted to minimal alveolar concentration (MAC) 1–1,5% according to haemodynamics. After the end of surgery, residual neuromuscular relaxation was reversed by Neostigmine (0.03_0.07 mg/ kg) and Atropine (0,02–0,1 mg/kg). Oropharyngeal suction was gently performed under direct vision by soft suction catheter with sideway port to avoid trauma to the tissues before extubation, one end of the catheter was attached to an aspirator or collection canister and the unattached end was placed directly into a tube to extract secretions safely without injury to the mucous membranes. Conclusion From this study including that addition of clonidine to dexamethasone was more superior in reducing POST & hoarseness of voice than dexamethasone alone, resulted in more haemodynamic stability in both intra operative and early post-operative period. Result From this study, there was statistically significant difference between the two studied groups regarding the sore throat and hoarseness of voice incidence and grade (P value < 0.05). so, Addition of clonidine to dexamethasone was more superior in reducing POST & hoarseness of voice than dexamethasone alone.