Anesthesia For ENT Surgeries Anesthesia For Ear, Nose and Throat Surgeries Common surgeriesExternal ear • Removal of simple lesions • Foreign bodies in ext.auditory canal • Preauricular abnormalities • Exostoses Anesthesia For Ear, Nose and Throat Surgeries Middle ear , Mastoid and throat: • Adenoidectomy • Tonsillectomy • Otitis media • Mastoidectomy • Tympanoplasty • Myringoplasty Anesthesia For Ear, Nose and Throat Surgeries Inner ear • Cochlear transplant surgery • Endolymphatic sac decompression • Labyrinthectomy Type of Anesthesia General Anesthesia • A through preoperative assessment advised. • Specific attention paid to hypertension or any cardiovascular disease which limits attempts to intraoperative control BP. • No specific premedication required • Beta blocker or clonidine if required can be given iv with intraoperative monitoring. PERIOPERATIVE MANAGEMENT History and investigations: • Detailed history and examination (especially airway assessment and relevant pathology). • Assessment of comorbidities, previous anesthetic history. • Smoking and alcohol consumption. • Screening for obstructive sleep apnea. PERIOPERATIVE MANAGEMENT History and investigations : • Relevant and targeted investigations. • Preoperative endoscopic airway examination. • Review of airway imaging: CT, MRI scans. • Preop. optimization if possible, e.g. nutritional status, respiratory system. PERIOPERATIVE MANAGEMENT Premedication: • Avoid sedative medication if there is any suggestion of airway compromise. • Consider gastric acid prophylaxis. PERIOPERATIVE PREPARATION Airway equipment • Laryngoscopes with a variety of blades • Video laryngoscopes, fibreoptic scopes, optical stylets (Bonfils). • Variety of ET tubes standard, preformed, reinforced, laser tubes. • Supraglottic airway devices. • Bougies, stylets, exchange catheters and other airway adjuncts. • Jet ventilation equipment. PERIOPERATIVE PREPARATION Airway equipment • Jet ventilation equipment. • Cricothryroidotomy/tracheostomy equipment. • Equipment for topical application of LA for airway. • Difficult airway trolley. PERIOPERATIVE PREPARATION Establish IV access Monitoring: • Standard monitoring • Neuromuscular monitoring • Core temperature • Invasive monitoring may be required depending on comorbities, injuries; extent, complexity and duration of surgery PERIOPERATIVE PREPARATION Preoxygenation • Face mask • Nasal oxygenation during efforts securing a tube • THRIVE (Transnasal Humidified RapidInsufflation Ventilatory Exchange) Transnasal Humidified Rapid-Insufflation Ventilatory Exchange o Mechanisms of action • Warmth & humidification allows higher flows • Flush dead space in nasopharynx decreases CO2 • Warmed, humidified – less constriction, more compliance • Distending pressure • Apneic oxygenation PERIOPERATIVE PREPARATION Induction: • IV or inhalational induction or awake intubation • Titrate to patient response; rapid sequence if warranted • Rocuronium is a good choice, with neostigmine available to reverse if required • Sevoflurane or desflurane • Remifentanil, alfentanil, fentanyl • Steroids for swelling and antiemesis • Antibiotics SAFE USE OF A THROAT PACK A throat pack is used to prevent blood and debris contaminating the airway or being swallowed. Throat packs are often inserted to: • Absorb material created by surgery in the mouth • Prevent fluids or material from entering the oesophagus or lungs • Prevent escape of gases from around tracheal tubes • To stabilize artificial airways SAFE USE OF A THROAT PACK If a throat pack is retained after surgery it can lead to obstruction of the airway and result in significant morbidity or mortality. The National Patient Safety Agency (NPSA) recommends: 1• Label or mark patient either on the head or, exceptionally, on another visible part of the body with an adherent sticker or marker. 2• Label artificial airway (e.g. tracheal tube or supraglottic airway). 3• Attach pack securely to the artificial airway. 4• Leave part of pack protruding. 5• Formalized and recorded ‘two-person’ check of insertion and removal of pack MAINTENANCE OF ANESTHESIA • Oxygen and air with inhalational agent or TIVA. • Remifentanil infusion. • Head-up position and relative hypotension can reduce bleeding and aid surgical field. Careful neck extension to improve access to neck and glottis. EXTUBATION Throat pack must be removed and confirmed by team members at sign out. Airway clear of secretions and blood. Assessment of airway edema: presence of leak around tube when cuff is down is suggestive that airway is not overly edematous. Plan for extubation using the DAS guidelines. POSTOPERATIVELY • Depending on patient and surgery, return to day case facility, head and neck ward, HDU or ICU. • Analgesia is not a particular problem: use a multimodal approach with LA, paracetamol, NSAIDs and opiates. • Antiemetics. • Important complications relate to airway compromise. A level of high vigilance must be maintained by all staff. Anesthesia For Tonsillectomy And Adenoidectomy PROCEDURE • A day case surgery (adult or children) • Adenotonsillar hypertrophy can present with nasal obstruction, recurrent infections, secretory otitis media, deafness (secondary to Eustachian tube dysfunction), and obstructive sleep apnea (OSA) [not a day case]. • Adenoidectomy and/or tonsillectomy procedures are performed through the mouth. A Boyle– Davis gag is used for tonsillectomy. Difficulties may be encountered because of poorly placed gag, obstructing the tracheal tube or laryngeal mask airway. PATIENT CHARACTERISTICS Chronic/recurrent throat infections. Comorbidities • Obstructive sleep apnoea • Congenital abnormalities, e.g. Down syndrome. • Older adults for tonsillectomy • May have malignancy. • Other incidental medical conditions. • Cor pulmonale due to long-term hypoxia. PREOPERATIVE MANAGEMENT Detailed assessment and appropriate investigations Assess for OSA • STOP-BANG questionnaire • Epworth sleep score • Bleeding history is important. • Detailed airway assessment (LEMON). • Possible difficult management due to large tonsils. PERIOPERATIVE MANAGEMENT • Anxiolytic if essential but avoid if a history of airway obstruction or OSA. • Standard monitoring. • Intravenous or inhalational induction. • Airway: Intubate with a preformed oral or reinforced tube. Reinforced laryngeal mask PERIOPERATIVE MANAGEMENT • Oral tubes must be carefully secured in the midline in order to lie correctly in the Boyle– Davis gag. • Patients are positioned with the neck extended. • Instrumentation of the postnasal space during adenoidectomy may induce a bradycardia requiring treatment with atropine or glycopyrrolate. PERIOPERATIVE MANAGEMENT Analgesia • Opioid analgesia is usually required. • IV paracetamol. • NSAIDs unless contraindicated. • Infiltration of local anaesthetic into the tonsillar bed. Careful suctioning of the pharynx under direct vision. Extubation either deep or awake POSTOPERATIVE MANAGEMENT • NSAIDs have not been found to significantly increase bleeding in tonsillectomy patients. • Maintain IV access in case of early postoperative bleeding. • Bleeding may not be detected in children until vomiting occurs. • Severe OSA patients have a higher incidence of perioperative complications and may need postoperative HDU/ICU care. • Routine use of antiemetic drugs to prevent PONV is recommended. Anesthesia For Esophagoscopy Introduction Two types of esophagoscopy are possible: rigid and flexible fiberoptic. Rigid esophagoscopy necessitates general anesthesia, whereas flexible is well tolerated with topical anesthesia ± sedation in adults. INDICATIONS • Removal of foreign body/food bolus • Investigation of carcinoma, e.g. as part of panendoscopy • Dilatation of strictures • Assessment and treatment of oesophageal/ pharyngeal lesion • Endoscopic treatment of pharyngeal pouch CONSIDERATIONS • Obstruction poses an aspiration risk with food and saliva present above the level of obstruction. • Chronic obstruction may result in weight loss, dehydration and silent aspiration. • Pre-existing comorbidities, e.g. cardiovascular disease, GORD, neurological conditions (dysphagia may be a presenting symptom). PREOPERATIVE PREPARATION • Investigate according to underlying cause. • Treat dehydration or chest infection. • Avoid sedating premedication. • Measures to neutralize gastric acid take time to be effective; there will still be a danger from blood, food and secretions above the level of obstruction. CONDUCT OF ANAESTHESIA • Shared airway with ENT surgeons so ensure good communication. • Rapid sequence induction and endotracheal intubation is mandatory (with a tube smaller than usual) due to risk of regurgitation. Avoid hand ventilation if possible to prevent further impaction of foreign bodies. • Secure tube to the left to allow for the esophagoscope – the tube can become kinked; consider a reinforced tube and pay close attention to airway pressures. CONDUCT OF ANAESTHESIA • IV induction and short-acting muscle relaxant are required. • Desflurane allows prompt return of airway reflexes. • Use neuromuscular monitoring and reverse if necessary. • Cardiovascular disturbance should be expected. In the presence of dehydration or cachexia, hypotension may occur. Hypertension and tachycardia are common and should be dealt with promptly, particularly in the elderly or those with cardiovascular disease. Fentanyl or alfentanyl can attenuate this response. POSTOPERATIVE CONSIDERATIONS • Patients remain an aspiration risk; therefore, extubate awake and fully reversed reflexes. • Odynophagia (pain when swallowing) may indicate esophageal perforation and can lead to pneumomediastinum, mediastinitis, pneumothorax and surgical emphysema. If there is suspicion of this, a chest X-ray and prompt discussion with the surgeons are necessary. • Ensure IV fluids are prescribed if the patient is to remain nil by mouth postoperatively. Anesthesia For Middle Ear Surgeries Introduction • Surgery to the external and middle ear structures tends to be elective for improvement of patient quality of life whether through restoration of hearing, decrement of infection or improvement of cosmetic defects. • Careful dissection of small structures is involved such as ossicles, using an operating microscope. The surgical field must be as free of blood as possible. A small amount of blood can obscure the surgeon’s view through the microscope. Injury to the facial nerve is possible with an incidence of 0.5%–3.5%. PERIOPERATIVE MANAGEMENT • Detailed assessment and investigations specific for the individual patient. • Premedication is required. MONITORING • Standard minimum monitoring. • Neuromuscular monitoring. • Invasive blood pressure monitoring if hypotensive anesthesia is requested in certain patients. POSITIONING • Head and neck will be rotated to the opposite side from the operative field. Avoid hyperextension of the neck to minimise chance of brachial plexus injury. • Extreme lateral head movement can be avoided by using lateral tilt of the operating table. • The dependent ear and eye should be free of excessive pressure especially in long cases, with use of a head ring. • Head-up tilt of 10–15° helps to minimize bleeding. AIRWAY • Endotracheal tube is commonly used. • Laryngeal mask may suffice but careful seating and seal must be confirmed with the head turned to the operative site. • Long anesthesia circuit tubing is required. • Recheck all connections and that gas exchange and ventilation are optimal in the final surgical position prior to draping. MAINTENANCE • TIVA using propofol. • Inhalational agent. • Remifentanil. • Protect eyes. • Bleeding must be minimised. The severity of bleeding is related as much to venous as to arterial blood pressure. • A clear airway is essential. A partially obstructed airway impedes expiration, increases CO2 levels and raises venous pressure. An armored endotracheal tube avoids kinking. MAINTENANCE • Anesthesia should be smooth. Avoid straining and coughing as they increase venous pressure and bleeding. • Avoid tachycardia. Beta-blockers are useful – small doses of labetalol, esmolol or metoprolol can be titrated intravenously. • Induced hypotension may be requested. Profound hypotension is unnecessary and may be harmful. FACIAL NERVE MONITORING • Intubate with small amount of relaxant and allow to wear off or reverse. • Use nerve stimulator to monitor block. • Alternatively intubate with opiates and LA spray to cords. • Use a laryngeal mask. NITROUS OXIDE The use of N2O is controversial. Its accumulation in the closed middle ear space is problematic especially in the presence of eustachian tube blockage. This results in an increase in middle ear pressure. During tympanoplasty, the tympanic membrane graft may become dislodged. It also increases PONV. If tympanoplasty, stapedotomy or stapedectomy is planned, N2O should be avoided. RECOVERY • The ear is bandaged at the end of the procedure. To prevent displacement of the tracheal tube and trauma to the eyes, the anesthetist should supervise this. • Nausea, vomiting and dizziness can be a particular problem following these procedures. Antiemetics should be given using a multimodal approach and not a single agent. Pain is not usually severe. Anesthesia For Operations On The Nose Introduction These can be simple and straightforward, e.g. manipulation of nasal bones; or they may be more complex and prolonged, e.g. transnasal skull base surgery. Septoplasty is performed to relieve symptoms of nasal obstruction or as a component of rhinoplasty. It can be combined with turbinate reduction surgery, or to facilitated CPAP in OSA patients. Rhinoplasty is performed for cosmetic or reconstructive surgery, post-trauma, reconstruction after tumor resection or to improve nasal breathing. Introduction A bloodless field is helpful and the aim is for a still patient with no or minimal coughing and straining followed by a smooth emergence. Some operations such as septoplasty may be performed under local anesthesia with sedation in cooperative patients although most nasal operations require a general anesthetic. • Submucus resection of septum, septoplasty, turbinectomy, polypectomy, antral washout, rhinectomy. PREOPERATIVE PREPARATION • Detailed history and examination with appropriate investigations. • Patients with polyps often have a history of atopy or the triad of asthma, polyps and aspirin sensitivity. • Postnasal drip and recurrent chest infections are common. • Treat chest infections and optimize chronic medical conditions. PREOPERATIVE PREPARATION • Patient with nasal fractures may have sustained other injuries or swallowed a significant amount of blood. • Correct any hypovolemia in patients who have bled significantly. • There is an increasing incidence of patients with obstructive sleep apnea. • Anxiolytic premedication if required. PREOPERATIVE PREPARATION Vasoconstrictors will reduce bleeding from nasal surgery and can be administered as a spray, paste, infiltration or on soaked swabs: • Moffatt’s solution (2 mL 8% cocaine, 2 mL 1% sodium bicarbonate and 1 mL 1:1000 epinephrine). • Modified Moffatt’s solution (10% cocaine and 8.4% bicarbonate). • Local anesthetic with 1:100,000–1:200,000 epinephrine. • Lidocaine 5% and phenylephrine 0.5% spray. • Xylometazoline (A nasal vasoconstricting decongestant drug)spray. • Cocaine 4%–10% (recommended maximum dose 1.5 mg/kg). INTRAOPERATIVE MANAGEMENT • Routine monitoring. • A rapid sequence induction is required as patients may have swallowed a significant amount of blood. • Induction agent of anesthetist’s choice. • Oral preformed or reinforced tracheal tube. Some use a laryngeal mask. • A throat pack is inserted, if required. • Protect eyes with ointment but not covered in order that the surgeon can check for orbital perforation or damage to the optic nerve. MAINTENANCE AND EXTUBATION • Inhalational agent and opiates (e.g. Remifentanil infusion) • TIVA • Muscle relaxant as necessary. • Head-up position with the thighs flexed at the hip in order to improve venous return. • When the procedure is complete, perform pharyngoscopy to ensure that the pack has been removed completely and any remaining blood clots or debris are aspirated. • Extubate awake sitting up. POSTOPERATIVE MANAGEMENT • Encourage the patient to breathe through his or her mouth because nasal packs are often in place. • Plasters and bolsters applied to the nose may make the application of a facemask difficult. • Administer oxygen in recovery in a routine fashion but CPAP is required as soon as possible in OSA patients. • Leave the intravenous cannula in situ in case of bleeding. • Repacking may be necessary should bleeding from the nose continue. • Regular paracetamol and NSAIDs are usually adequate. Opioids are needed following more extensive surgery but be aware of respiratory depression in OSA patients. Prescribe an antiemetic.