BRITISH JOURNAL OF ANAESTHESIA
1266 very difficult to achieve, because what constitutes "no reasonable prospect of survival" today, may not apply tomorrow, because knowledge and experience will have changed. There is certainly no place for pride or prejudice in making these decisions. What is required is a careful weighing of the available evidence. Certainly this may be difficult, but that does not absolve doctors who work in intensive therapy units from the responsibility of doing so. J. F. SEARLE
Exeter REFERENCES
(1961) state that where this condition is found, the most effective treatment is a reasonable, accurate explanation of what has happened. Having regard to the difficulties experienced in the case described above, this explanation should not go further than stating that the patient was resistant to the anaesthetic agents used! Routine visiting of patients after operation will help to detect similar unfortunate cases, but the patients may first describe their unpleasant recurrent dreams resulting from neuroleptanalgesia, or actual awareness, to their general practitioner. Such patients should be referred back to the anaesthetist concerned, for investigation and treatment.
Bishop, V. A. (1978). A nurse's view of ethical problems in intensive care and clinical research. Br. J. Anaesth., 50, J. M. CUNDY 515. London Hare, R. M., and Mitchell, B. G. (1975). Moral considerations; in On Dying Well. An Anglican Contribution to the REFERENCES Debate on Euthanasia, p. 5. London: Church Information Editorial (1956). Consciousness during surgical operations. Office. Br. Med. J., 2, 810. Payne, J. P. (1978). Ethical problems in clinical research and Hutter, C , and Tomlin, P. J. (1978), Awareness during intensive care. Br. J. Anaesth., 50, 413. anaesthesia. Br. J. Anaesth., 50, 307. Statement (1976). Diagnosis of brain death. Br. Med.J., 2, Meyer, B. C , and Blacker, R. S. (1961). N. Y. State J. Med., 1187. 61, 1955. AWARENESS DURING ANAESTHESIA
Sir,—In view of the comment on a legal action brought for awareness during anaesthesia (Hutter and Tomlin, 1978) it may be useful to describe the points of interest to anaesthetists in a case in which I was asked to advise. The case was heard some 6 years after the event and all the hospital staff concerned were unable to recall any of the "facts" recounted in the Plaintiff's description of a very unpleasant occurrence. The first independent medical witness to corroborate the Plaintiff's story did not see her until 18 months after the event. The Judge noted this failure to corroborate the story, the considerable delay before the action was commenced, and he decided that awareness had not occurred. The Court heard that techniques associated with a risk of awareness were used by anaesthetists where deeper anaesthesia was considered dangerous, as for instance during Caesarean section. Anaesthetists who use techniques associated with a substantial risk of awareness, without a specific clinical indication should realize that both parties accepted the patient's right to be unconscious and not to suffer pain during surgery (Editorial, 1956). In the 1977 Annual Report the Medical Defence Union referred to difficulties caused by the lack of detailed notes. I imagine that in the above case the prior offer of a small sum in settlement, without prejudice, reflected the genuine doubts concerning an adequate hearing of the case by the defence society concerned, as a result of such lack of annotation. Anaesthetists should be aware of "traumatic neuroses" similar to that suffered by this patient. Awareness during anaesthesia may form an intense psychological stress, particularly if pain is experienced in addition. Many patients feel degraded and humiliated by this and react by passive de-personalization. They believe themselves to be mad and may make no effort to relate to staff what had occurred. This patient said that she had hidden in her bedroom on her return home, since she felt unable to meet her family. A similar state may follow anaesthetic dreams and can last for several months. Mayer and Blacker
DIFFICULTY IN INTUBATION
Sir,—After reading Dr Dennison's letter (1978) I feel bound to ask if it was all really necessary. At our hospital, which is a centre for, amongst other things, rheumatoid arthritis, the problem of difficult intubation has largely been avoided. If we can, we choose extradural analgesia, but when general anaesthesia is unavoidable, we obtain x-rays of the cervical spine to assess the possibility of cord compression at the odontoid, and we check the degree of jaw mobility, during the visit before operation. Where we suspect that tracheal intubation by conventional techniques would be difficult, impossible or unsafe, we prefer to anaesthetize the patient with halothane via a mask and airway or a naso-pharyngeal tube. Halothane, with spontaneous breathing, is perhaps not the ideal anaesthetic for a patient with rheumatoid arthritis undergoing a major orthopaedic operation, but we feel that it is kinder to the patient (and the anaesthetist) than a long and traumatic intubation. We have generally reserved the use of a flexible bronchoscope, under sedation, for neurosurgical patients in whom intubation is obligatory. ROGER FLETCHER
Lund, Sweden REFERENCE
Dennison, P. H. (1978). Four experiences in intubation of one patient with Still's disease. Br. J. Anaesth., 50, 636. SIR,—You seem to have had a spate of letters recently about difficult intubations. I presume that these reported difficulties are only a small fraction of the total, most of which is unreported. I sometimes see people struggling valiantly to intubate patients with the cervical spine extended, and that the majority of my colleagues adopt this position is suggested by the difficulty I have in preventing nurses trying to be helpful by whipping all the pillows out as soon as the patient is asleep.
1267
CORRESPONDENCE Magill was perhaps too poetic for the humdrum English when he called it the position of sniffing the morning air. The position is illustrated more earthily on the backs of some of our buses, where the Bisto kids are shown getting a whiff of their scrumptious bottled gravy. Their cervical spines are flexed—straightened, for extension increases the curvature, and only the atlanto-occipital joints are extended. P. H. BEVES
Kidderminster
Sir,—I have read Dr Dennison's letter on the use of the flexible fibreoptic laryngoscope with great interest. I have had some experience of using this instrument during the past year and although I share Dr Dennison's obvious enthusiasm, I have found that it takes considerable practice to become competent in its use. I would not advise anyone to rely on using it in a difficult situation without previous experience. (I note that Dr Dennison had performed 300 intubations with it before the case of Miss C. W.!) The size of the instrument causes two problems. First, the smallest diameter of nasal tube which will fit comfortably over it is 8.0 mm. This limits its use to older teenagers and adults. Second, it is sometimes not possible to pass it down either nostril, even in the adult. Occasionally the instrument will pass through the nose and into the trachea, but is such a tight fit in the nostril that the endotracheal tube will not pass through the nostril. In addition, vision is obscured frequently by the following: (1) Mist forming over the end-piece—this can be minimized by the use of an anti-misting substance. (2) Mucous, blood or lubricating jelly, which may be removed only by withdrawing the instrument and cleaning the tip. The presence of blood in the nostril can be a difficult recurring problem. Other factors which help to improve laryngoscopy with this.instrument are: (1) Adjustment of the focus of the eye-piece. After experimenting with different positions, I have found the midpoint of the range to be the most helpful. (2) Adequate pre-oxygenation of the patient before induction of anaesthesia prolongs the time available for intubation. Easy intubations may be accomplished within 60-90 s, but more difficult ones can take considerably longer. (3) An assistant holding the jaw forward allows an unimpeded view of the larynx which is otherwise obscured by the posterior aspect of the tongue. The image obtained of the larynx is tiny compared with the normal size seen by conventional laryngoscopy. Recognition of this and manoeuvre of the tip of the laryngoscope towards it are not difficult, but require practice. This instrument is undoubtedly a very significant addition to our armamentarium for the patient in whom endotracheal intubation is difficult. J. M. ANDERTON
Manchester REFERENCE
Dennison, P. H. (1978). Four experiences in intubation of one patient with Still's disease. Br. J. Anaesth., 50, 636.
TEST-DOSES I N EXTRADURAL ANALGESIA
Sir,—With regard to the recent controversy in your pages on test-doses in extradural analgesia (Boys, 1977; Galloon, 1978; Scott, 1978), I wish to report an episode of an extradural catheter migrating into the subarachnoid space. A 31-year-old female undergoing Caesarean section was placed in the left lateral position and a 17-G Tuohy needle was inserted at the L2-L3 interspace into the extradural space, using the loss of resistance test. A 19-G catheter was advanced into the extradural space. After inserting the catheter 5 cm cephalad, paraesthesiae were noted in the left leg. The needle and catheter were withdrawn simultaneously 1 cm and the paraesthesiae disappeared. The catheter was taped in place, and the patient was taken to the operating suite. She was placed in the sitting position, the catheter aspirated with no fluid return, and 2 ml of chloroprocaine 3% was injected easily. After 5 min, when no evidence of spinal block appeared, 14 ml of chloroprocaine 3% were injected over 1 min. The patient remained in the sitting position for 5 min, and was then placed supine. After 8 min, sensory analgesia was present bilaterally to T7 and the operation commenced. After negative aspiration (but without a test-dose) an additional 6 ml of chloroprocaine 3% was injected and the sensory block attained the level of T5. Ten minutes after the last injection, pink fluid was noted dripping from the end of the catheter at a rate of 1 drop every 3 s. Three millilitre of fluid was aspirated easily and testing was negative for glucose, but there was a trace of protein and blood. It was thought that the fluid was local anaesthetic, since its flow seemed to be affected by uterine manipulation. Nevertheless, a sample of the fluid and a quantity of chloroprocaine 3% were sent to the laboratory for measurement of glucose and protein concentration, and a venous blood sample was obtained for the measurement of blood glucose concentration. At the end of the procedure the patient showed no evidence of a spinal block and she had active toe movements bilaterally. The catheter was removed immediately and found to be intact. Two hours after termination of the procedure, results were available from the laboratory and they revealed: Catheter fluid: glucose 4.94 mmol litre"1, protein 0 Blood: glucose 8.44 mmol litre" 1 3% chloroprocaine: glucose 0.39 mmol litre"1, protein 0 These results suggest that the catheter had migrated into the dural canal while the patient was supine and immobile, even though such episodes may be "so infrequent" (Bonica, 1967). Thus it would appear that the use of a test-dose of local anaesthetic in continuous extradural analgesia is worth while. JOSEPH A. STIRT
Los Angeles, California REFERENCES
Bonica, J. J. (1967). Principles and Practice of Obstetric Analgesia and Anesthesia, p. 579. Philadelphia: F. A. Davis Co. Boys, J. E. (1977). Analgesia in labour. Br. J. Anaesth., 49, 841. Galloon, S. (1978). Test doses in extradural analgesia. Br.J. Anaesth., 50,304. Scott, D. B. (1978). Test doses in extradural analgesia. Br.J. Anaesth., 50,304.
1266 very difficult to achieve, because what constitutes "no reasonable prospect of survival" today, may not apply tomorrow, because knowledge and experience will have changed. There is certainly no place for pride or prejudice in making these decisions. What is required is a careful weighing of the available evidence. Certainly this may be difficult, but that does not absolve doctors who work in intensive therapy units from the responsibility of doing so. J. F. SEARLE
Exeter REFERENCES
(1961) state that where this condition is found, the most effective treatment is a reasonable, accurate explanation of what has happened. Having regard to the difficulties experienced in the case described above, this explanation should not go further than stating that the patient was resistant to the anaesthetic agents used! Routine visiting of patients after operation will help to detect similar unfortunate cases, but the patients may first describe their unpleasant recurrent dreams resulting from neuroleptanalgesia, or actual awareness, to their general practitioner. Such patients should be referred back to the anaesthetist concerned, for investigation and treatment.
Bishop, V. A. (1978). A nurse's view of ethical problems in intensive care and clinical research. Br. J. Anaesth., 50, J. M. CUNDY 515. London Hare, R. M., and Mitchell, B. G. (1975). Moral considerations; in On Dying Well. An Anglican Contribution to the REFERENCES Debate on Euthanasia, p. 5. London: Church Information Editorial (1956). Consciousness during surgical operations. Office. Br. Med. J., 2, 810. Payne, J. P. (1978). Ethical problems in clinical research and Hutter, C , and Tomlin, P. J. (1978), Awareness during intensive care. Br. J. Anaesth., 50, 413. anaesthesia. Br. J. Anaesth., 50, 307. Statement (1976). Diagnosis of brain death. Br. Med.J., 2, Meyer, B. C , and Blacker, R. S. (1961). N. Y. State J. Med., 1187. 61, 1955. AWARENESS DURING ANAESTHESIA
Sir,—In view of the comment on a legal action brought for awareness during anaesthesia (Hutter and Tomlin, 1978) it may be useful to describe the points of interest to anaesthetists in a case in which I was asked to advise. The case was heard some 6 years after the event and all the hospital staff concerned were unable to recall any of the "facts" recounted in the Plaintiff's description of a very unpleasant occurrence. The first independent medical witness to corroborate the Plaintiff's story did not see her until 18 months after the event. The Judge noted this failure to corroborate the story, the considerable delay before the action was commenced, and he decided that awareness had not occurred. The Court heard that techniques associated with a risk of awareness were used by anaesthetists where deeper anaesthesia was considered dangerous, as for instance during Caesarean section. Anaesthetists who use techniques associated with a substantial risk of awareness, without a specific clinical indication should realize that both parties accepted the patient's right to be unconscious and not to suffer pain during surgery (Editorial, 1956). In the 1977 Annual Report the Medical Defence Union referred to difficulties caused by the lack of detailed notes. I imagine that in the above case the prior offer of a small sum in settlement, without prejudice, reflected the genuine doubts concerning an adequate hearing of the case by the defence society concerned, as a result of such lack of annotation. Anaesthetists should be aware of "traumatic neuroses" similar to that suffered by this patient. Awareness during anaesthesia may form an intense psychological stress, particularly if pain is experienced in addition. Many patients feel degraded and humiliated by this and react by passive de-personalization. They believe themselves to be mad and may make no effort to relate to staff what had occurred. This patient said that she had hidden in her bedroom on her return home, since she felt unable to meet her family. A similar state may follow anaesthetic dreams and can last for several months. Mayer and Blacker
DIFFICULTY IN INTUBATION
Sir,—After reading Dr Dennison's letter (1978) I feel bound to ask if it was all really necessary. At our hospital, which is a centre for, amongst other things, rheumatoid arthritis, the problem of difficult intubation has largely been avoided. If we can, we choose extradural analgesia, but when general anaesthesia is unavoidable, we obtain x-rays of the cervical spine to assess the possibility of cord compression at the odontoid, and we check the degree of jaw mobility, during the visit before operation. Where we suspect that tracheal intubation by conventional techniques would be difficult, impossible or unsafe, we prefer to anaesthetize the patient with halothane via a mask and airway or a naso-pharyngeal tube. Halothane, with spontaneous breathing, is perhaps not the ideal anaesthetic for a patient with rheumatoid arthritis undergoing a major orthopaedic operation, but we feel that it is kinder to the patient (and the anaesthetist) than a long and traumatic intubation. We have generally reserved the use of a flexible bronchoscope, under sedation, for neurosurgical patients in whom intubation is obligatory. ROGER FLETCHER
Lund, Sweden REFERENCE
Dennison, P. H. (1978). Four experiences in intubation of one patient with Still's disease. Br. J. Anaesth., 50, 636. SIR,—You seem to have had a spate of letters recently about difficult intubations. I presume that these reported difficulties are only a small fraction of the total, most of which is unreported. I sometimes see people struggling valiantly to intubate patients with the cervical spine extended, and that the majority of my colleagues adopt this position is suggested by the difficulty I have in preventing nurses trying to be helpful by whipping all the pillows out as soon as the patient is asleep.
1267
CORRESPONDENCE Magill was perhaps too poetic for the humdrum English when he called it the position of sniffing the morning air. The position is illustrated more earthily on the backs of some of our buses, where the Bisto kids are shown getting a whiff of their scrumptious bottled gravy. Their cervical spines are flexed—straightened, for extension increases the curvature, and only the atlanto-occipital joints are extended. P. H. BEVES
Kidderminster
Sir,—I have read Dr Dennison's letter on the use of the flexible fibreoptic laryngoscope with great interest. I have had some experience of using this instrument during the past year and although I share Dr Dennison's obvious enthusiasm, I have found that it takes considerable practice to become competent in its use. I would not advise anyone to rely on using it in a difficult situation without previous experience. (I note that Dr Dennison had performed 300 intubations with it before the case of Miss C. W.!) The size of the instrument causes two problems. First, the smallest diameter of nasal tube which will fit comfortably over it is 8.0 mm. This limits its use to older teenagers and adults. Second, it is sometimes not possible to pass it down either nostril, even in the adult. Occasionally the instrument will pass through the nose and into the trachea, but is such a tight fit in the nostril that the endotracheal tube will not pass through the nostril. In addition, vision is obscured frequently by the following: (1) Mist forming over the end-piece—this can be minimized by the use of an anti-misting substance. (2) Mucous, blood or lubricating jelly, which may be removed only by withdrawing the instrument and cleaning the tip. The presence of blood in the nostril can be a difficult recurring problem. Other factors which help to improve laryngoscopy with this.instrument are: (1) Adjustment of the focus of the eye-piece. After experimenting with different positions, I have found the midpoint of the range to be the most helpful. (2) Adequate pre-oxygenation of the patient before induction of anaesthesia prolongs the time available for intubation. Easy intubations may be accomplished within 60-90 s, but more difficult ones can take considerably longer. (3) An assistant holding the jaw forward allows an unimpeded view of the larynx which is otherwise obscured by the posterior aspect of the tongue. The image obtained of the larynx is tiny compared with the normal size seen by conventional laryngoscopy. Recognition of this and manoeuvre of the tip of the laryngoscope towards it are not difficult, but require practice. This instrument is undoubtedly a very significant addition to our armamentarium for the patient in whom endotracheal intubation is difficult. J. M. ANDERTON
Manchester REFERENCE
Dennison, P. H. (1978). Four experiences in intubation of one patient with Still's disease. Br. J. Anaesth., 50, 636.
TEST-DOSES I N EXTRADURAL ANALGESIA
Sir,—With regard to the recent controversy in your pages on test-doses in extradural analgesia (Boys, 1977; Galloon, 1978; Scott, 1978), I wish to report an episode of an extradural catheter migrating into the subarachnoid space. A 31-year-old female undergoing Caesarean section was placed in the left lateral position and a 17-G Tuohy needle was inserted at the L2-L3 interspace into the extradural space, using the loss of resistance test. A 19-G catheter was advanced into the extradural space. After inserting the catheter 5 cm cephalad, paraesthesiae were noted in the left leg. The needle and catheter were withdrawn simultaneously 1 cm and the paraesthesiae disappeared. The catheter was taped in place, and the patient was taken to the operating suite. She was placed in the sitting position, the catheter aspirated with no fluid return, and 2 ml of chloroprocaine 3% was injected easily. After 5 min, when no evidence of spinal block appeared, 14 ml of chloroprocaine 3% were injected over 1 min. The patient remained in the sitting position for 5 min, and was then placed supine. After 8 min, sensory analgesia was present bilaterally to T7 and the operation commenced. After negative aspiration (but without a test-dose) an additional 6 ml of chloroprocaine 3% was injected and the sensory block attained the level of T5. Ten minutes after the last injection, pink fluid was noted dripping from the end of the catheter at a rate of 1 drop every 3 s. Three millilitre of fluid was aspirated easily and testing was negative for glucose, but there was a trace of protein and blood. It was thought that the fluid was local anaesthetic, since its flow seemed to be affected by uterine manipulation. Nevertheless, a sample of the fluid and a quantity of chloroprocaine 3% were sent to the laboratory for measurement of glucose and protein concentration, and a venous blood sample was obtained for the measurement of blood glucose concentration. At the end of the procedure the patient showed no evidence of a spinal block and she had active toe movements bilaterally. The catheter was removed immediately and found to be intact. Two hours after termination of the procedure, results were available from the laboratory and they revealed: Catheter fluid: glucose 4.94 mmol litre"1, protein 0 Blood: glucose 8.44 mmol litre" 1 3% chloroprocaine: glucose 0.39 mmol litre"1, protein 0 These results suggest that the catheter had migrated into the dural canal while the patient was supine and immobile, even though such episodes may be "so infrequent" (Bonica, 1967). Thus it would appear that the use of a test-dose of local anaesthetic in continuous extradural analgesia is worth while. JOSEPH A. STIRT
Los Angeles, California REFERENCES
Bonica, J. J. (1967). Principles and Practice of Obstetric Analgesia and Anesthesia, p. 579. Philadelphia: F. A. Davis Co. Boys, J. E. (1977). Analgesia in labour. Br. J. Anaesth., 49, 841. Galloon, S. (1978). Test doses in extradural analgesia. Br.J. Anaesth., 50,304. Scott, D. B. (1978). Test doses in extradural analgesia. Br.J. Anaesth., 50,304.
