Thyroid disease

Br J Anaesth 2000; 85: 15–28 Disease of the thyroid gland is common. For example, in endemic areas, the incidence of goitre is 15–30% of the adult population.66Mostbeck A Galvan G Bauer P et al.The incidence of hyperthyroidism in Austria from 1987 to 1995 before and after an increase in salt iodization in 1990.Eur J Nucl Med. 1998; 25: 367-374Crossref PubMed Scopus (92) Google Scholar Most anaesthetists, although their practice may not include endocrine surgery, will frequently be required to manage patients with thyroid disease. Thyroid diseases that have anaesthetic implications include hypothyroidism, hyperthyroidism and conditions requiring thyroidectomy. Those presenting with well-controlled hypo- and hyperthyroidism do not present much difficulty for the anaesthetist. However, patients with uncontrolled myxoedema, or those with uncontrolled hyperthyroidism presenting as an emergency, are at considerable risk.42James ML Endocrine disease and anaesthesia.Anaesthesia. 1970; 25: 232-252Crossref PubMed Scopus (19) Google Scholar Anaesthesia for thyroidectomy may be complicated by airway problems such as retrosternal extension of the gland. The anaesthetist should, therefore, pay particular attention to preoperative assessment of the airway and should be able to deal with acute airway complications in the perioperative phase. In his book entitled The History of Endocrine Surgery, Richard Welbourn details the beginnings of thyroidectomy.99Welbourn RB The History of Endocrine Surgery. Praeger, New York1990: 19-82Google Scholar Goitres were recognized in antiquity and were described in Chinese literature in 2700 bc. Since they were never endemic around the Mediterranean, there was no mention of goitre in Egyptian or Greek writings. In the twelfth and thirteenth centuries, the school of Salerno in Italy was the cradle of thyroid surgery. At that time goitres were removed using horrific-sounding instruments such as setons, hot irons, stypics and asphodel powder. The American surgeon William Halsted could trace accounts of only eight operations in which the scalpel was used between 1596 and 1800. During one of these procedures, described by Fabricius in 1646, the patient, a 10-yr-old girl, died on the table and the surgeon was gaoled! In 1821, Hedenus reported the successful removal of six suffocating goitres by dissection and ligation of all the arteries. Needless to say, these operations were prone to complications which were often fatal and, in 1850, the French Academy of Medicine condemned operations on the thyroid gland. However, the advances of anaesthesia, antisepsis and haemostasis allowed surgeons, such as Billroth of Vienna and Kocher of Berne, to perform many more thyroid operations with reduced mortality. In 1849, Nikolai Pirogoff of St Petersburg was the first to use general anaesthesia for a thyroid operation. He used ether on a girl of 17 yr whose goitre was causing tracheal compression.99Welbourn RB The History of Endocrine Surgery. Praeger, New York1990: 19-82Google Scholar Thomas Peel Dunhill performed his first thyroidectomy in 1907 under local anaesthetic.94Vellar ID Thomas Peel Dunhill: pioneer thyroid surgeon.Austral New Zeal J Surg. 1999; 69: 375-387Crossref PubMed Scopus (18) Google Scholar He developed surgery as an effective and safe treatment for thyrotoxicosis and in 1911 presented his series of 230 cases of exophthalmic goitre, which included only four deaths. Other notable thyroid surgeons included Charles Mayo and George Crile. In the UK, Stanley Rowbotham was a pioneer of anaesthesia for thyroid surgery;18Condon HA Gilchrist E Stanley Rowbotham. Twentieth century pioneer anaesthetist.Anaesthesia. 1986; 41: 46-52Crossref PubMed Scopus (13) Google Scholar with his surgeon Cecil Joll, he performed 946 goitre operations between 1941 and 1944. Although these operations were performed before the introduction of antithyroid drugs, by Astwood in 1943,7Astwood EB Treatment of hyperthyroidism with thiourea and thiouracil.J Am Med Assoc. 1943; 122: 78-81Crossref Scopus (90) Google Scholar there were only nine deaths in the series. Rowbotham combined local analgesia with light general anaesthesia and even contrived, at the request of the surgeon, to get the patient to strain when the haemostatic sutures were in place. He used one breath of ether to accomplish this manoeuvre.76Rowbotham E Anaesthesia for Operations for Goitre. Blackwell, Oxford1945Google Scholar The incidence of hypothyroidism depends on the level of iodide in the diet.66Mostbeck A Galvan G Bauer P et al.The incidence of hyperthyroidism in Austria from 1987 to 1995 before and after an increase in salt iodization in 1990.Eur J Nucl Med. 1998; 25: 367-374Crossref PubMed Scopus (92) Google Scholar The prevalence of overt hypothyroidism in iodine-sufficient areas is five per 1000 and that for the subclinical form is 15 per 1000.55Lind P Langsteger W Molnar M Gallowitsch HJ Mikosch P Gomez I Epidemiology of thyroid diseases in iodine sufficiency.Thyroid. 1998; 8: 1179-1183Crossref PubMed Scopus (144) Google Scholar Hypothyroidism may result in depression of myocardial function, decreased spontaneous ventilation, abnormal baroreceptor function, reduced plasma volume, anaemia,82Singh V Catlett JP Hematologic manifestations of thyroid disease.Endocrinologist. 1998; 8: 87-91Crossref Scopus (13) Google Scholar hypoglycaemia, hyponatraemia and impaired hepatic drug metabolism.67Murkin JM Anesthesia and hypothyroidism: A review of thyroxine physiology, pharmacology and anesthetic implications.Anesth Analges. 1982; 61: 371-383Crossref PubMed Google Scholar Hypothyroid patients should be rendered euthyroid before surgery42James ML Endocrine disease and anaesthesia.Anaesthesia. 1970; 25: 232-252Crossref PubMed Scopus (19) Google Scholar and, as with other types of endocrine surgery, close communication with the metabolic physicians is advised. It should be remembered that, because thyroxine (T4) has a half-life of 7 days, it will not have an effect for some time after administration. The half-life of tri-iodothyronine (T3) is 1.5 days. The combination of intravenous T3 and T4 is recommended in the management of preoperative myxoedematous coma, which is an extremely rare occurrence. Careful administration is essential, particularly in the elderly, as angina may be precipitated.60Mathes DD Treatment of myxedema coma for emergency surgery.Anesth Analges. 1998; 6: 450-451Google Scholar There is some debate about whether or not surgery should be postponed in a mild or subclinical hypothyroid patient.10Bennett-Guerrero E Kramer DC Schwinn DA Effect of chronic and acute thyroid hormone reduction on perioperative outcome.Anesth Analges. 1997; 85: 30-36PubMed Google Scholar It is logical to avoid premedication in overtly hypothyroid patients and to use regional anaesthesia wherever possible. T4 may be omitted on the morning of surgery but it is advisable to give the patient's usual morning dose of T3. The presence of a hypometabolic state necessitates careful perioperative cardiovascular monitoring and judicious use of anaesthetic drugs. Preventative measures should be adopted to protect against hypothermia. Because of an increased incidence of adrenocortical insufficiency and a reduced adrenocorticotropic hormone response to stress, hypothyroid patients should receive hydrocortisone cover during periods of increased surgical stress.67Murkin JM Anesthesia and hypothyroidism: A review of thyroxine physiology, pharmacology and anesthetic implications.Anesth Analges. 1982; 61: 371-383Crossref PubMed Google Scholar There are several reports of severe cardiovascular and respiratory depression in hypothyroid patients during general anaesthesia. Hypothyroidism should therefore be considered in any obese, debilitated patient who displays perioperative cardiovascular or respiratory instability.54Levelle JP Jopling MW Sklar GS Perioperative hypothyroidism: an unusual postanesthetic diagnosis.Anesthesiology. 1985; 63: 195-197Crossref PubMed Scopus (20) Google Scholar Thyrotoxicosis affects approximately 2% of women and 0.2% of men in the general population.27Franklyn J Thyrotoxicosis.Prescrib J. 1999; 39: 1-8Google Scholar The prevalence of overt hyperthyroidism in iodine-sufficient areas is two per 1000 and that of subclinical hyperthyroidism is six per 1000.55Lind P Langsteger W Molnar M Gallowitsch HJ Mikosch P Gomez I Epidemiology of thyroid diseases in iodine sufficiency.Thyroid. 1998; 8: 1179-1183Crossref PubMed Scopus (144) Google Scholar The classical features of thyrotoxicosis are well known and include hyperactivity, weight loss and tremor. Of importance to the anaesthetist are the cardiovascular effects of hyperthyroidism including atrial fibrillation, congestive cardiac failure and ischaemic heart disease.44Kahaly GJ Nieswandt J Mohr-Kahaly S Cardiac risks of hyperthyroidism in the elderly.Thyroid. 1998; 8: 1165-1169Crossref PubMed Scopus (43) Google Scholar Thrombocytopaenia may be associated with thyrotoxicosis.82Singh V Catlett JP Hematologic manifestations of thyroid disease.Endocrinologist. 1998; 8: 87-91Crossref Scopus (13) Google Scholar General anaesthesia should be considered as the method of choice for patients with exophthalmos requiring eye surgery.17Clarke PM Kozeis N A complication of peribulbar block in a patient with exophthalmos.Br J Anaesth. 1998; 81: 615Crossref PubMed Scopus (4) Google Scholar In an attempt to prevent the dreaded complication of ‘thyroid storm’, patients should be euthyroid before surgery.42James ML Endocrine disease and anaesthesia.Anaesthesia. 1970; 25: 232-252Crossref PubMed Scopus (19) Google Scholar 86Stehling LC Anesthetic management of the patient with hyperthyroidism.Anesthesiology. 1974; 41: 585-595Crossref PubMed Scopus (22) Google Scholar This is achieved by the use of antithyroid drugs, commonly carbimazole or propylthiouracil. These drugs block the synthesis of thyroxine but take 6–8 weeks to work. Beta-blockers, particularly propranolol, are used to ameliorate the effects of thyrotoxicosis13Black JW Crowther AF Shanks RG Smith LH Dornhurst AC New adrenergic beta-receptor antagonist.Lancet. 1964; i: 1080-1081Abstract Scopus (234) Google Scholar and are effective in the acute preoperative phase. Longer-acting beta-blockers such as atenolol or nadolol may achieve better control of symptoms.27Franklyn J Thyrotoxicosis.Prescrib J. 1999; 39: 1-8Google Scholar 36Hamilton WF Forrest AL Gunn A Peden NR Feely J Beta-adrenoceptor blockade and anaesthesia for thyroidectomy.Anaesthesia. 1984; 39: 335-342Crossref PubMed Scopus (15) Google Scholar Anaesthetic drugs may be affected by the hypermetabolic state of hyperthyroidism. For example, the clearance and distribution volume of propofol are increased in hyperthyroid patients. When total intravenous anaesthesia is used, propofol infusion rates should be increased to reach anaesthetic blood concentrations.91Tsubokawa T Yamamoto K Kobayashi T Propofol clearance and distribution volume increase in patients with hyperthyroidism.Anesth Analges. 1998; 87: 195-199PubMed Google Scholar The hypermetabolic crisis known as ‘thyroid storm’ is frequently mentioned in textbooks of anaesthesia72Nimmo WS Rowbotham DJ Smith G Anaesthesia. 2nd edn. Blackwell, Oxford1994: 1107Google Scholar but is now rarely seen because of the widespread use of anti-thyroid drugs, such as carbimazole, and beta-blockers. However, thyroid crisis still occurs in uncontrolled hyperthyroid patients as a result of a trigger such as surgery, infection or trauma. Pugh and colleagues described a case following Caesarean section73Pugh S Lalwani K Awal A Thyroid storm as a cause of loss of consciousness following anaesthesia for emergency caesarean section.Anaesthesia. 1994; 49: 35-37Crossref PubMed Scopus (26) Google Scholar and Naito and colleagues described a tragic case resulting from active metastatic thyroid carcinoma in a severely burned patient.68Naito Y Sone T Kataoka K Sawada M Yamazaki K Thyroid storm due to functioning metastatic thyroid carcinoma in a burn patient.Anesthesiology. 1997; 87: 433-435Crossref PubMed Scopus (24) Google Scholar Supportive management of thyroid crisis includes hydration, cooling, inotropes and, formerly, steroids. Beta-blockade, using propranolol, and antithyroid drugs are used as the first-line of treatment. Esmolol was successful in treating a child of 14 months who developed a thyroid crisis 3 h after thyroidectomy.47Knighton JD Crosse MM Anaesthetic management of childhood thyrotoxicosis and the use of esmolol.Anaesthesia. 1997; 52: 67-70Crossref PubMed Scopus (15) Google Scholar An 85-yr-old with multinodular goitre and severe thyrotoxicosis was also managed with esmolol.95Vijayakumar HR Thomas WO Ferrara JJ Peri-operative management of severe thyrotoxicosis with esmolol.Anaesthesia. 1989; 44: 406-408Crossref PubMed Scopus (13) Google Scholar However, it should be noted that thyroid crisis has been reported during beta-blockade.85Strube PJ Thyroid storm during beta blockade.Anaesthesia. 1984; 39: 343-346Crossref PubMed Scopus (22) Google Scholar An acute thyroid crisis on induction of anaesthesia, which was mistakenly diagnosed as malignant hyperthermia, was treated successfully by boluses of dantrolene 1 mg kg −1.9Bennett MH Wainwright AP Acute thyroid crisis on induction of anaesthesia.Anaesthesia. 1989; 44: 28-30Crossref PubMed Scopus (38) Google Scholar Christensen and Nissen reported the successful use of dantrolene to treat thyroid crisis in a child who had not responded to traditional measures.16Christensen PA Nissen LR Treatment of thyroid storm in a child with dantrolene.Br J Anaesth. 1987; 59: 523Crossref PubMed Scopus (5) Google Scholar Since thyroid hormones sensitize the adrenergic receptors to endogenous catecholamines, magnesium sulphate would seem to be, theoretically, a useful drug. Magnesium reduces the incidence and severity of dysrhythmias caused by catecholamines (James MFM, personal communication). The indications for thyroidectomy include: proven or suspected thyroid malignancy; obstructive symptoms; retrosternal goitre, even in the absence of obstruction; hyperthyroidism that is unresponsive to medical management; recurrent hyperthyroidism; cosmetic reasons; anxiety (patients with a small goitre may insist on having it removed); patients with Hashimoto's disease, goitre and hypothyroidism usually respond to thyroxine therapy, but thyroidectomy would be indicated if there is any suspicion of superimposed lymphoma.90Todesco J Williams RT Anaesthetic management of a patient with a large neck mass.Can J Anaesth. 1994; 41: 157-160Crossref PubMed Scopus (2) Google Scholar General history taking and examination of patients scheduled for thyroidectomy should include identification of abnormalities of thyroid function. Besides symptoms and signs of hypo- and hyperthyroidism, evidence of other medical conditions should be sought, particularly cardiorespiratory disease and associated endocrine disorders. For example, patients who require thyroidectomy for medullary cancer may have an associated phaeochromocytoma.101Zatterale A Stabile M Nunziata V Di Giovanni G Vecchione R Ventruto V Multiple endocrine neoplasia type 2 (Sipple's syndrome): clinical and cytogenetic analysis of a kindred.J Med Genet. 1984; 21: 108-111Crossref PubMed Scopus (19) Google Scholar Problems with airway management will be the main concern of the anaesthetist when confronted by a patient with a goitre. The patient may give a history of respiratory difficulties, for example positional dyspnoea, and this may be associated with a degree of dysphagia. As described later, patients with retrosternal goitre may exhibit signs of vena caval obstruction. Other assessments of the airway will include assessment of distances between incisors, the thyromental distance, the degree of protrusion of the lower teeth, head and neck mobility and observation of pharyngeal structures.75Rose DK Cohen MM The airway problems and predictions in 18500 patients.Can J Anaesth. 1994; 41: 372-383Crossref PubMed Scopus (503) Google Scholar Routine investigations include thyroid function tests, haemoglobin, white cell and platelet count, urea and electrolytes, including serum calcium, chest x-ray and indirect laryngoscopy. Patients may have had fine needle aspiration as a diagnostic test in the out-patient clinic. An ENT colleague routinely performs indirect laryngoscopy in order to document any preoperative vocal cord dysfunction.77Rowe-Jones JM Rosswick RP Leighton SE Benign thyroid disease and vocal cord palsy.Ann Roy Coll Surg Engl. 1993; 75: 241-244PubMed Google Scholar This investigation is useful to the anaesthetist since the need for a fibreoptic instrument to view the vocal cords, if indirect laryngoscopy is unsuccessful, will alert the anaesthetist to the probability of a difficult intubation. A chest x-ray (Fig. 1) is requested to seek evidence of tracheal compression and deviation and lateral thoracic inlet views have traditionally been used to show tracheal compression in the antero-posterior plane (Fig. 2).Fig 2Lateral thoracic inlet x-ray showing tracheal compression antero-posteriorly.View Large Image Figure ViewerDownload (PPT) Other investigations, while not routine, will be of value in certain cases. Computerized tomography (CT) can provide excellent views of retrosternal goitres8Barker P Mason RA Thorpe MH Computerised axial tomography of the trachea. A useful investigation when a retrosternal goitre causes symptomatic tracheal compression.Anaesthesia. 1991; 46: 195-198Crossref PubMed Scopus (10) Google Scholar (Fig. 3): compare the reconstructed CT scan in Fig. 4 with the chest x-ray of the same patient (Fig. 1).Fig 4Reconstructed CT scan.View Large Image Figure ViewerDownload (PPT) Magnetic resonance imaging (MRI) has the advantage of providing images in the sagittal and coronal planes, as well as transverse views28Freitas JE Freitas AE Thyroid and parathyroid imaging.Semin Nucl Med. 1994; 24: 234-245Abstract Full Text PDF PubMed Scopus (55) Google Scholar (Fig 5, Fig 6, Fig 7). The coronal view of this patient (Fig. 6) indicated that it would not be possible to see the larynx by direct laryngoscopy and so fibreoptic intubation was planned.Fig 6Coronal MRI scan of goitre.View Large Image Figure ViewerDownload (PPT)Fig 7Transverse MRI scan of goitre.View Large Image Figure ViewerDownload (PPT) The usefulness of respiratory function tests is debatable. Respiratory flow volume loops showed upper airway obstruction in 33% of 153 consecutive patients presenting with thyroid enlargement. This was unrelated to the type or size of goitre.33Gittoes NJL Miller MR Daykin J Sheppard MC Franklyn JA Upper airways obstruction in 153 consecutive patients presenting with thyroid enlargement.Br Med J. 1996; 312: 484Crossref PubMed Scopus (72) Google Scholar Following a careful history and examination and with the assistance of a number of investigations, the anaesthetist can be in a position to discuss with the patient the various options for airway management. These options will include straightforward intravenous induction with tracheal intubation, inhalational induction or fibreoptic intubation. The patient should be warned what to expect postoperatively and an anxiolytic premedication prescribed. It is possible to perform thyroidectomy under bilateral deep or superficial cervical plexus blocks.50Kulkarni RS Braverman LE Patwardhan NA Bilateral cervical plexus block for thyroidectomy and parathyroidectomy in healthy and high risk patients.J Endocrinol Invest. 1996; 19: 714-718Crossref PubMed Scopus (38) Google Scholar There are, however, a number of complications of this technique, including vertebral artery puncture, epidural subarachnoid spread and bilateral phrenic nerve block. Regional anaesthesia is a useful alternative for particular circumstances, for example, thyroidectomy for amiodarone-induced hyperthyroidism.46Klein SM Greengrass RA Knudsen N Leight G Warner DS Regional anesthesia for thyroidectomy in two patients with amiodarone-induced hyperthyroidism.Anesth Analges. 1997; 85: 222-224Crossref PubMed Google Scholar Thyroidectomy under regional anaesthesia is not routinely practised in the UK. In some parts of the world, thyroidectomy is performed under acupuncture, with or without supplementary analgesics.45Kho HG van Egmond J Zhuang CF Lin GF Zhang GL Acupuncture anaesthesia. Observations on its use for removal of thyroid adenomata and influence on recovery and morbidity in a Chinese hospital.Anaesthesia. 1990; 45: 480-485Crossref PubMed Scopus (12) Google Scholar Hypnosedation, a combination of hypnosis and light conscious sedation, has been suggested for endocrine surgery including thyroidectomy.64Meurisse M Faymonville ME Joris J Nguyen Dang D Defechereux T Hamoir E Endocrine surgery by hypnosis. From fiction to daily clinical application.Ann d’Endocrinol. 1996; 57: 494-501PubMed Google Scholar General anaesthesia with tracheal intubation and muscle relaxation is the most popular anaesthetic technique for thyroidectomy. The laryngeal mask airway (LMA †LMA® is the property of Intavent Limited. )14Brain AIJ The laryngeal mask—a new concept in airway management.Br J Anaesth. 1983; 55: 801-804Crossref PubMed Scopus (775) Google Scholar has been used with spontaneous respiration and intermittent positive pressure ventilation in thyroid surgery.34Greatorex RA Denny NM Application of the laryngeal mask airway to thyroid surgery and the preservation of the recurrent laryngeal nerve.Ann R Coll Surg Engl. 1991; 73: 352-354PubMed Google Scholar 38Hobbiger HE Allen JG Greatorex RG Denny NM The laryngeal mask airway for thyroid and parathyroid surgery.Anaesthesia. 1996; 51: 972-974Crossref PubMed Scopus (34) Google Scholar 88Tanigawa K Yoshitaka I Sadayuki I Protection of the recurrent laryngeal nerve during neck surgery.Anesthesiology. 1991; 74: 966-967Crossref PubMed Scopus (22) Google Scholar This technique requires close co-operation between surgeon and anaesthetist. Relative contraindications to the use of the LMA include tracheal narrowing and/or deviation. As described in the section on postoperative complications, use of the LMA allows vocal cord movement to be seen via a fibreoptic laryngoscope when the recurrent laryngeal nerve is stimulated.88Tanigawa K Yoshitaka I Sadayuki I Protection of the recurrent laryngeal nerve during neck surgery.Anesthesiology. 1991; 74: 966-967Crossref PubMed Scopus (22) Google Scholar However, there is a risk that the LMA will be displaced during surgery and laryngospasm occurs in relation to surgical manipulation.15Charters P Cave-Bigley D Roysam CS Should a laryngeal mask be routinely used in patients undergoing thyroid surgery?.Anesthesiology. 1991; 75: 918-919Crossref PubMed Scopus (6) Google Scholar Use of the intubating laryngeal mask in a patient with a large goitre proved difficult because of deviation of the laryngeal inlet.96Wakeling HG Ody A Ball A Large goitre causing difficult intubation and failure to intubate using the intubating laryngeal mask airway: lessons for next time.Br J Anaesth. 1998; 81: 979-981Crossref PubMed Scopus (29) Google Scholar Induction of anaesthesia for routine thyroidectomy, when no difficulty with intubation is expected, is straightforward. The trachea is intubated usually using conventional laryngoscopy. The tracheal tube should not kink when it attains body temperature during prolonged surgery, so a reinforced tube should be considered (Fig. 8). ‘North-polar’ oral tracheal tubes (Fig. 9) are an alternative as they keep the respiratory filter away from the surgical field. Nasal tracheal tubes may also be used although vasoconstriction will be required to prevent epistaxis. It is wise to select a small reinforced tracheal tube if there is any degree of tracheal compression.Fig 9‘North-polar’ tracheal tube.View Large Image Figure ViewerDownload (PPT) Occasionally, even though no difficulty has been predicted, the larynx is not easily seen, so the anaesthetic team must be experienced and prepared to cope with an unexpected difficult intubation. Items which should be available to deal with such a situation include: various sizes of tracheal tubes; gum elastic bougies; a levering laryngoscope;61McCoy ÉP Mirakhur RK The Levering laryngoscope.Anaesthesia. 1993; 48: 516-519Crossref PubMed Scopus (105) Google Scholar straight-bladed laryngoscopes; an LMA;14Brain AIJ The laryngeal mask—a new concept in airway management.Br J Anaesth. 1983; 55: 801-804Crossref PubMed Scopus (775) Google Scholar ready access to an intubating fibrescope; and some means of trans-tracheal ventilation. If preoperative airway assessment and/or the inability of the ENT surgeon to see the vocal cords by indirect laryngoscopy have predicted any difficulty with intubation, then the anaesthetist must have a clear strategy for intubation. The anaesthetist should expect that 6% of tracheal intubations for thyroid surgery will be difficult.51Lacoste L Gineste D Karayan J et al.Airway complications in thyroid surgery.Ann Otol Rhinol Laryngol. 1993; 102: 441-446Crossref PubMed Scopus (101) Google Scholar It has been reported that the ease of intubation was unrelated to the extent of abnormality seen on imaging studies of the neck.62McHenry CR Piotrowski JJ Thyroidectomy in patients with marked thyroid enlargement: airway management, morbidity, and outcome.Am Surg. 1994; 60: 5865-5891Google Scholar Whenever there is concern that the airway will be lost if anaesthesia is induced, awake fibreoptic intubation is the method of choice. The traditional technique of inhalational induction has regained acceptability following the introduction of sevoflurane.57MacIntyre PA Ansari KA Sevoflurane for predicted difficult tracheal intubation.Eur J Anaesthesiol. 1998; 15: 462-466Crossref PubMed Scopus (29) Google Scholar 98Watters MP McKenzie JM Inhalational induction with sevoflurane in an adult with severe complex central airways obstruction.Anaesth Intensive Care. 1997; 25: 704-706PubMed Google Scholar It may be adopted when the patient is extremely anxious about awake intubation, and the anaesthetist believes that the size of the goitre will not cause the airway to be lost after induction of anaesthesia. After intubation, by whatever means, the position of the tracheal tube is checked, the tube is secured and the patient's eyes are protected. These practical points are important as the use of head towels prevents the anaesthetist from inspecting the patient's face during the procedure. Particular care should be taken when the patient suffers from exophthalmos. The patient is positioned with a sandbag between the shoulder blades and the head resting on a padded ‘horseshoe’ or Whitlock headrest100Whitlock RI Headrest for oral surgery.Br J Oral Surg. 1964; 2: 104Abstract Full Text PDF PubMed Scopus (1) Google Scholar (Fig. 10). Both arms are placed by the side, as the surgeon will need to stand on either side of the patient. A long connector for the i.v. infusion allows access from the foot of the bed. A 25° upward tilt of the head will assist venous drainage, although this should be performed with careful attention to arterial pressure, particularly in patients who have been receiving beta-blockers. Finally, slight head extension will allow the surgeon excellent access to the thyroid gland. The skin is infiltrated with 10–20 ml of 0.5% bupivacaine and epinephrine 1:200 000. Skin flaps are raised and the strap muscles separated in the midline. It is rarely necessary to divide the strap muscles. The upper pole is mobilized and the superior thyroid vessels ligated. Mobilization of the lobe is completed and the parathyroid glands and recurrent laryngeal nerve are identified routinely and protected during dissection of the thyroid from the trachea. Haemostasis is secured and the strap muscles and platysmal layers apposed. The skin is closed with staples.30Gardiner KR Russell CFJ Thyroidectomy for large multinodular goitre.J Roy Coll Surg Edin. 1995; 40: 367-370PubMed Google Scholar Residual neuromuscular block is reversed and the patient is allowed to recover from anaesthesia. If there has been any concern during dissection of the recurrent laryngeal nerve, the vocal cords are checked and the surgeon reassured. A fibreoptic endoscope may be used to view the vocal cords atraumatically.59Maroof M Siddique M Khan RM Post-thyroidectomy vocal cord examination by fibreoscopy aided by the laryngeal mask airway.Anaesthesia. 1992; 47: 445Crossref PubMed Scopus (15) Google Scholar When adequate spontaneous respiration and laryngeal reflexes have returned, the patient is extubated. Every attempt should be made to prevent coughing,32Gefke K Andersen LW Friesel E Lidocaine given intravenously as a suppressant of cough and laryngospasm in connection with extubation after tonsillectomy.Acta Anaesthesiol Scand. 1983; 27: 111-112Crossref PubMed Scopus (52) Google Scholar 40Huang CJ Hsu YW Chen CC et al.Prevention of coughing induced by endotracheal tube during emergence from general anesthesia—a comparison between three different regimens of lidocaine filled in the endotracheal tube cuff.Acta Anaesthesiol Sin. 1998; 36: 81-86PubMed Google Scholar 49Konrad C Gerber H Schnider T Schupfer G Is an alkalinized lignocaine solution a better topical anaesthetic for intratracheal application?.Eur J Anaesthesiol. 1997; 14: 616-622Crossref PubMed Scopus (2) Googl