The management of foreign bodies in air passages

Transcription

1 The management of foreign bodies in air passages S. Chatterji P. Chatterji The problems associated with inhaled foreign bodies receive little attention. Nevertheless, this is a very serious and life-endangering emergency which is quite frequently encountered. The removal of the foreign body presents considerable problems both to the endoscopist and the anaesthetist, in which the maintenance of an adequate airway, satisfactory pulmonary ventilation and a quick atraumatic removal of the foreign body remain the crux of the problem. Of all the foreign bodies which may be inhaled those of vegetable origin present the most difficulties, particularly if they are retained for a prolonged time. They then become markedly swollen and cause a vegetable bronchitis. Organic acids and oils contained within the foreign body are believed to contribute to the syndrome. PRESENTATIONS History If a history is forthcoming it may be helpful but it is surprisingly often absent. Any patient who is said to have choked or gagged or had a fit of coughing during eating must have a bronchoscopy before the possibility of foreign body can be ruled out. Patients may present so late that the initial symptoms have been forgotten. They present with the so-called syndrome of the forgotten foreign body with cough, sputum, fever, leucocytosis and chest X-ray showing an area of collapse and consolidation. Such patients frequently find their way into a medical ward. Antibiotics abate the signs and symptoms but complete amelioration fails to occur. Clinical signs Larynx. Signs and symptoms of foreign bodies in the larynx are very variable and depend on its size, shape and duration of lodgement. The signs may vary from a hoarseness of voice and cough to acute obstructive laryngeal dyspnoea with cyanosis, needing immediate relief. If a small endotracheal tube cannot be passed this may involve laryngotomy or tracheostomy. S. Chatterji, MD, Reader in Anaesthesiology and P. Chatterji, MS, Professor of ENT Diseases, S. M.S. Medical College and Hospital, Jaipur (Rajasthan), India. 390

2 Trachea. Foreign bodies in the trachea are relatively uncommon. Respiratory distress is much more marked than in cases of a foreign body in the bronchus. The usual presenting signs include an incessant irritating cough, a palpable thud, an audible flap, tracheal flutter and an asthmoid wheeze. The thud, flap and flutter are produced by the movement of the foreign body inside the tracheal lumen during respiration. Stridor may be present if the foreign body is lodged near the subglottic region. Bronchus. Foreign bodies in the bronchus rarely cause acute respiratory distress and air hunger and cyanosis are not marked. The most common presenting features are an irritating cough with pain on the affected side. A rise in temperature and foetid sputum develop when there is secondary infection, usually after two to three days. Foreign bodies in the right bronchus are twice as common as those in the left. Spontaneous expulsion occurs in only 1-2 % of cases. Types of bronchial obstruction The lodgement of a foreign body in a bronchus can give rise to five types of valvular obstruction, each with characteristic patho-physiological changes in the lungs and mediastinum. Check valve. This type of obstruction allows ingress of air during inspiration but not during expiration with a consequent obstructive emphysema. The trachea and cardiac shadow are shifted to the opposite side and the dome of the diaphragm is depressed. The picture develops rapidly during the early stages of an obstruction. Stop valve. This may occur in two ways and is associated with obstruction of a large air passage in both inspiration and expiration. It may occur when a large foreign body causes total occlusion from the time of inhalation, or it may develop in what had previously been a check valve type of obstruction after a vegetable body swells up and bronchitis develops. The picture is one of collapse and consolidation of the affected bronchopulmonary segment. In our experience this is the commonest presentation of a foreign body in the bronchus. Ball valve. This is typically associated with foreign bodies such as peas, beans or rounded smooth, metallic bodies such as pellets. In such cases, the foreign body is dislodged by the passage of air during expiration but re-impacts during inspiration. This type of obstruction, therefore, leads to early atelectasis and gives rise to an X-ray picture somewhat similar to that seen with a stopvalve obstruction. In both these latter cases, therefore, the mediastinal shift will be towards the affected side and the dome of the diaphragm elevated. By-pass valve. This occurs with foreign bodies which partialiy obstruct the lumen in both phases of respiration with reduction in ventilation past it. The involved lung field shows diminished aeration and opacity, without any marked mediastinal shift. 39 1

3 Anaesthesia ~0127 no 4 October 1972 It is well known that foreign bodies in the air passages may change their position. In these cases both the clinical signs and the X-ray picture may totally change and fresh X-rays must always be taken just prior to the attempted removal. Since the clinical signs are not totally reliable, chest X-rays in both inspiration and expiration should always be taken in both postereanterior and lateral views. MANAGEMENT It is always very helpful, if possible, to obtain a replica of the foreign body. This helps the endoscopist in selecting the forceps likely to be needed for the removal. A wide selection of forcep ends must be available and good endo-bronchial suction. A tracheostomy set must always be ready to hand. The anaesthetic problems associated with endoscopy of the upper airways are well known, and need no special elaboration here. The aim is to provide a tranquil, oxygenated patient with adequate pulmonary ventilation, in whom tracheal and bronchial reflexes have been adequately obtunded, and to provide these conditions for sufficient time so that the foreign body can be found and removed in an unhurried fashionl. To the general problems associated with endoscopy are added the problems of the preceding respiratory distress, inadequate ventilation or septic secretions. In pursuance of these general aims the anaesthetic technique may need to be modified according to the expected site of location of the foreign body and the age of the patient. If there has been a previous unsuccessful attempt at removal of the foreign body, or if an unduly long time is taken, we consider it advisable to perform a tracheostomy at the conclusion of the procedure. The administration of steroids is also helpful. Foreign bodies in the larynx A laryngeal foreign body usually lies at the laryngeal inlet, partly obstructing the lumen and causes stridor or respiratory distress. In our experience a Bhurut (a type of thorn seed found in India) may stick to the false cords or true cords without respiratory distress. In children under the age of one year, with respiratory distress, it is best to undertake a preliminary tracheostomy. If laryngeal obstruction is acute a small endotracheal tube should be passed immediately prior to tracheostomy. It may be possible then to remove the foreign body without further anaesthesia. If anaesthesia is necessary it can be conveniently administered via the tracheostomy. In children under one year of age who do not have respiratory distress the whole procedure should preferably be done without anaesthesia. In older children and adults with stridor or respiratory distress, induction with halothane and oxygen is smooth and well tolerated. Pre-medication should be with atropine only. After induction, the larynx should be 392

4 sprayed with 1-2ml of 4% lignocaine and anaesthesia then deepened. Within about five minutes anaesthesia is usually sufficiently deep to allow adequate time for removal of a laryngeal foreign body without further anaesthesia. Halothane appears to us to be a better choice than the somewhat stormy inductions which may occur with ethyl chloride and ether. Thiopentone and suxamethonium may also lead one into difficulties; if pre-oxygenation is inadequate, positive pressure ventilation may be necessary and this may dislodge the foreign body into one of the bronchi. In the absence of airway obstruction these considerations are less serious and an intravenous induction followed by suxamethonium may well be ideal. Adequate pre-oxygenation can sometimes obviate the need for positive pressure ventilation before the removal of the foreign body. Whenever a thiopentone/suxamethonium sequence is employed one must prepare for the possibility that injudicious positive pressure ventilation may dislodge the foreign body onwards and preparation for bronchoscopic removal should always be made, even in the case of a Iaryngeal foreign body. If intravenous induction is not possible then a nitrous oxideoxygen-halothane sequence can be satisfactorily employed. Foreign bodies in a bronchus In infants and small children, particularly those with respiratory distress, there are two acceptable techniques. One is to anaesthetise the child deeply with ether and the second is to use a short-acting muscle relaxant interrupting the surgeon with periods of intermittent positive pressure ventilation. In really small infants the procedure may be carried out without anaesthesia. In older children and adults thiopentone induction followed by intermittent suxamethonium, and intermittent oxygenation via the bronchoscope is a satisfactory method. Many foreign bodies, once they are gripped by the forceps, are too large to be withdrawn through the lumen and a not infrequent complication is the loss of the foreign body from the forceps during the removal of the forceps and bronchoscope from the patient. This takes place as the foreign body passes through the sub-glottic region. If the suxamethonium has been wearing off there is a rapid onset of cyanosis with laryngeal spasm. An open vein through which suxamethonium can be quickly administered is essential. Intravenous lignocaine technique Various techniques have been described for coping with the general problems of anaesthesia during bronchoscopy, and include a tube alongside the bronchoscope2, manual compression of the chest 3, an external inflatable cuirass4, or intermittently interrupting the surgeon and inflating via an endotracheal tube inserted in the bronchoscope 5. A convenient alternative method has been used by us for some time based on the method 393

5 Anaesthesia vol27 no 4 October I972 described in 1969 by Blancato et al.6 based on earlier studies798 and involving the use of intravenous lignocaine. It is especially suitable for older children and adults. The patients are premedicated with atropine, pethidine and promezathine in appropriate doses, about 45 minutes before the induction of anaesthesia. An intravenous infusion of 5 % glucose is started and lignocaine 1 % slowly injected in a dose of from 10-20m1, depending on the weight of the patient. Total dose of lignocaine should be limited to 3-4mg/kg body weight. This is followed by a sleep dose of thiopentone. During the administration of thiopentone, the patient is allowed to inhale oxygen and nitrous oxide in a proportion of 25 litres. As soon as the jaw is relaxed the pharynx and larynx are sprayed with lignocaine 4 % under direct vision. Nitrous oxide and oxygen are administered again for about a minute before the surgeon starts. Lignocaine and thiopentone are administered through the intravenous drip as and when required. If there is slight bucking, a swab soaked in lignocaine 4% is touched on the carina and the bronchial mucosa. Throughout this period N20 and 0 2 are administered through the side tube of the bronchoscope. The advantages of this method have seemed to us to be : (1) There is no hurry about the completion of the operative procedure because the patient is breathing spontaneously throughout. (2) None of our patients has had severe bouts of coughing in the postoperative period as have cases anaesthetised by the thiopentone-suxamethonium sequence. (3) If the removal of the foreign body is difficult because of impaction, a small dose of suxamethonium can be administered to facilitate the creation of forceps space. (4) The danger of prolonged apnoea or dual block due to suxamethonium is completely avoided. (5) There is good post-operative analgesia. CONCLUSIONS It must be borne in mind that removal of a foreign body from the air passages is a very serious and risky operation. In every case, whatever the anaesthetic technique, the following things must be kept ready: (1) A patent vein (kept patent by a running intravenous drip or a nonclotting needle). (2) Facilities for quick endotracheal intubation. (3) A tracheostomy set. (4) Some means of giving oxygen and positive pressure ventilation. (5) A good suction machine and different sizes of aspirating tubes for tracheo-bronchial toilet. 394

6 SUMMARY The problems associated with the management of foreign bodies in air passages are discussed, together with the patho-physiological changes. The anaesthetic management appropriate to foreign bodies in various locations at different ages is described, together with an account of the use of intravenous lignocaine with thiopentone. Acknowledgement We thank Astra A.B., Sodertalje, Sweden (local supplier Suhrid Geigy Ltd, Wadi Wadi, Baroda) for their liberal supply of lignocaine for intravenous use. References 1 Robinson,C.L.N. & Mushin,W.W. (1956). Inhaled foreign bodies. British Medical Journal, ii, 324 * Cheatle,C.A. & Chambers,K.B. (1955). Anaesthesia for bronchoscopy. Anaesthesia, 10, Kelsal1,P.D. (1954). Anaesthesia for bronchoscopy. British Journal of Anaesthesia, 26, Pinkerton,H.H. (1957). The use of an inflatable cuirass in endoscopy. British Journal ofdnaesthesia, 29,421 5 Churchill-Davidson,H.C. (1 952). Anaesthesia for bronchoscopy. Anaesthesia, 7,237 6 Blancato,L.S., Peng,A.T.C. & Alonsabe,D. (1969). Intravenous lidocaine as an adjunct to general anesthesia for endoscopy. Anesthesia and Analgesia, Current Researches, 48,224 7 Steinhaus,J.E. & Howland,D.E. (1958). Intravenously administered lidocaine as a supplement to nitrous oxide-thiobarbiturate anesthesia. Anesthesia and Analgesia, Current Researches, Steinhaus,J.E. & Gaskin,L. (1968). A study of intravenous lidocaine as a suppressant of cough reflex. Anesthesiology, 24,