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FAILED TRACHEAL INTUBATION
CORRESPONDENCE
225
J. A. W. WlLDSMITH Edinburgh
REFERENCES 1. levins FA. Accuracy of placement of cxtradural needles in the L3-4 interspace: comparison of two methods of identifying L4. British Journal of Anaesthesia 1991; 66: 381-382. 2. Lee JJ, Parry H. Bacterial meningitis following spinal anaesthesia for Caesarean section. British Journal of Anaesthesia 1991; 66: 383-386.
Sir,—Thank you for the opportunity of replying. I agree that all the standard texts advocate drawing Turner's line on the subject's back. However, it is my experience, gained in several units and from watching many practitioners, that extradurals are frequently sited by lying the patient on the side, palpating the upper iliac crest and running the hand down to the vertebral column, rather than palpating both iliac crests and joining them. It is precisely this need for meticulous attention to detail that I was trying to convey. Regarding the comments concerning the risk to the spinal cord. I did not intend to imply that thoracic extradural blocks are dangerous. Rather, I was trying to draw attention to the fact that intradural needles, if sited higher than anticipated, might put at risk a cord terminating lower than normal. F. A. IEVINS
Solihull
FAILED TRACHEAL INTUBATION Sir,—Dr King and Professor Adams correctly state that the Laryngeal Mask Airway (LMA) has been used successfully after failed intubation at Caesarean section [1, 2]. However, if a decision is made to insert the LMA in the obstetric patient we would question the timing of insertion, which they state should be after spontaneous ventilation has resumed. We would suggest that when failure to intubate has been acknowledged, and in the unfortunate situation that the patient's lungs are difficult or impossible to ventilate manually, the LMA should be inserted at that time rather than wait until the gravity of the situation has rectified itself by resumption of spontaneous ventilation. Alternatively, in the hopefully rare situation when it is felt that surgery must proceed in the patient in whom it is impossible to intubate the trachea, but
who has a reasonably clear airway, it might be prudent to pass the LMA in the still paralysed patient before spontaneous ventilation has resumed, as insertion of the LMA might be technically more straightforward. The correct use of the LMA provides a safer means of maintaining ventilation before last-ditch attempts at cricothyroid puncture or tracheotomy. G. O'SULLIVAN P. A. STODDART London
REFERENCES 1. King TA, Adams AP. Failed intubation. British Journal of Anaesthesia 1990; 65: 400-^14. 2. McClure S, Regan M, Moore J. Laryngeal mask airway for Caesarean section. Anaesthesia 1990; 45: 227-228. Sir,—Thank you for the opportunity to reply to this letter. We wish to draw attention to recent correspondence by Freeman and Baxendale, in which the possible dangers of insertion of the Brain laryngeal mask airway after a failed obstetric intubation are described clearly [1]. In our opinion, should ventilation with a face mask be easy after failed intubation in an obstetric patient, insertion of the Brain laryngeal mask airway at this stage would, at the very least, be meddlesome. This is the most critical stage, when one awaits return of spontaneous ventilation while maintaining oxygenation and preventing aspiration. In the event of inability to ventilate the patient's lungs with a face mask, insertion of the Brain laryngeal mask airway may well be appropriate. However, insertion of the laryngeal airway may not be straightforward under these circumstances and, as with tracheal intubation, prolonged attempts at insertion should be avoided. Cricothyroid puncture performed at the correct time with appropriate equipment will be life saving. T. A. KING A. P. ADAMS London
REFERENCE 1. Freeman R, Baxendale B. Laryngeal mask airway for Caesarean section. Anaesthesia 1990; 45: 1094-1095. TRACHEAL INTUBATION WITH THE PATIENT IN A SITTING POSITION Sir,—Occasionally, the anaesthetist is required to provide general anaesthesia for a patient with a difficult airway and a full stomach. In some instances, these patients may have concurrent cardiovascular or cerebrovascular disease or increased intracranial pressure, and would benefit from a smooth intubation technique that prevents wide variations in cardiovascular variables. With adequate topical and regional anaesthesia of the airway, the cardiovascular responses to laryngoscopy and intubation may be minimized; however, the risk of silent aspiration is greatly increased. Before the availability of the fibreoptic laryngoscope, the preferred technique was an awake intubation. Topical anaesthesia and sedation were kept to a minimum in an attempt to maintain the protective laryngeal reflexes and decrease the
Downloaded from http://bja.oxfordjournals.org/ at University of New South Wales on July 26, 2015
cannot agree that this was "despite meticulous aseptic techniques". It is clear that whoever gave the anaesthetic did not wear a surgical facemask. I believe that the anaesthetist should always wear such a mask when performing a central nerve block. During both preparation and needle insertion, the anterior nares and mouth are relatively close to, and usually immediately above, the sterile field. The arguments put forward in defence of the practice of not wearing a mask are based primarily on studies of ward practice and may not be relevant. The effect of contamination, especially with particulate matter, may be more significant because any bacteria that do gain access are placed in an ideal culture medium, which is relatively deficient in host defence mechanisms. Bacteria can, as this case shows, multiply very rapidly in that situation. In my opinion, a mask should be worn.
225
J. A. W. WlLDSMITH Edinburgh
REFERENCES 1. levins FA. Accuracy of placement of cxtradural needles in the L3-4 interspace: comparison of two methods of identifying L4. British Journal of Anaesthesia 1991; 66: 381-382. 2. Lee JJ, Parry H. Bacterial meningitis following spinal anaesthesia for Caesarean section. British Journal of Anaesthesia 1991; 66: 383-386.
Sir,—Thank you for the opportunity of replying. I agree that all the standard texts advocate drawing Turner's line on the subject's back. However, it is my experience, gained in several units and from watching many practitioners, that extradurals are frequently sited by lying the patient on the side, palpating the upper iliac crest and running the hand down to the vertebral column, rather than palpating both iliac crests and joining them. It is precisely this need for meticulous attention to detail that I was trying to convey. Regarding the comments concerning the risk to the spinal cord. I did not intend to imply that thoracic extradural blocks are dangerous. Rather, I was trying to draw attention to the fact that intradural needles, if sited higher than anticipated, might put at risk a cord terminating lower than normal. F. A. IEVINS
Solihull
FAILED TRACHEAL INTUBATION Sir,—Dr King and Professor Adams correctly state that the Laryngeal Mask Airway (LMA) has been used successfully after failed intubation at Caesarean section [1, 2]. However, if a decision is made to insert the LMA in the obstetric patient we would question the timing of insertion, which they state should be after spontaneous ventilation has resumed. We would suggest that when failure to intubate has been acknowledged, and in the unfortunate situation that the patient's lungs are difficult or impossible to ventilate manually, the LMA should be inserted at that time rather than wait until the gravity of the situation has rectified itself by resumption of spontaneous ventilation. Alternatively, in the hopefully rare situation when it is felt that surgery must proceed in the patient in whom it is impossible to intubate the trachea, but
who has a reasonably clear airway, it might be prudent to pass the LMA in the still paralysed patient before spontaneous ventilation has resumed, as insertion of the LMA might be technically more straightforward. The correct use of the LMA provides a safer means of maintaining ventilation before last-ditch attempts at cricothyroid puncture or tracheotomy. G. O'SULLIVAN P. A. STODDART London
REFERENCES 1. King TA, Adams AP. Failed intubation. British Journal of Anaesthesia 1990; 65: 400-^14. 2. McClure S, Regan M, Moore J. Laryngeal mask airway for Caesarean section. Anaesthesia 1990; 45: 227-228. Sir,—Thank you for the opportunity to reply to this letter. We wish to draw attention to recent correspondence by Freeman and Baxendale, in which the possible dangers of insertion of the Brain laryngeal mask airway after a failed obstetric intubation are described clearly [1]. In our opinion, should ventilation with a face mask be easy after failed intubation in an obstetric patient, insertion of the Brain laryngeal mask airway at this stage would, at the very least, be meddlesome. This is the most critical stage, when one awaits return of spontaneous ventilation while maintaining oxygenation and preventing aspiration. In the event of inability to ventilate the patient's lungs with a face mask, insertion of the Brain laryngeal mask airway may well be appropriate. However, insertion of the laryngeal airway may not be straightforward under these circumstances and, as with tracheal intubation, prolonged attempts at insertion should be avoided. Cricothyroid puncture performed at the correct time with appropriate equipment will be life saving. T. A. KING A. P. ADAMS London
REFERENCE 1. Freeman R, Baxendale B. Laryngeal mask airway for Caesarean section. Anaesthesia 1990; 45: 1094-1095. TRACHEAL INTUBATION WITH THE PATIENT IN A SITTING POSITION Sir,—Occasionally, the anaesthetist is required to provide general anaesthesia for a patient with a difficult airway and a full stomach. In some instances, these patients may have concurrent cardiovascular or cerebrovascular disease or increased intracranial pressure, and would benefit from a smooth intubation technique that prevents wide variations in cardiovascular variables. With adequate topical and regional anaesthesia of the airway, the cardiovascular responses to laryngoscopy and intubation may be minimized; however, the risk of silent aspiration is greatly increased. Before the availability of the fibreoptic laryngoscope, the preferred technique was an awake intubation. Topical anaesthesia and sedation were kept to a minimum in an attempt to maintain the protective laryngeal reflexes and decrease the
Downloaded from http://bja.oxfordjournals.org/ at University of New South Wales on July 26, 2015
cannot agree that this was "despite meticulous aseptic techniques". It is clear that whoever gave the anaesthetic did not wear a surgical facemask. I believe that the anaesthetist should always wear such a mask when performing a central nerve block. During both preparation and needle insertion, the anterior nares and mouth are relatively close to, and usually immediately above, the sterile field. The arguments put forward in defence of the practice of not wearing a mask are based primarily on studies of ward practice and may not be relevant. The effect of contamination, especially with particulate matter, may be more significant because any bacteria that do gain access are placed in an ideal culture medium, which is relatively deficient in host defence mechanisms. Bacteria can, as this case shows, multiply very rapidly in that situation. In my opinion, a mask should be worn.