Br.J. Anaesth. (1976), 48, 1029
CORRESPONDENCE PLASMA POTASSIUM AND INDUCTION AGENTS
REFERENCES
Sir,—I was interested to read that the combination of propanidid and suxamethonium was accompanied by significantly less muscle fasciculations than the combination of methohexitone and propanidid (Fry, 1975). Thisfindingmay explain the results of a recent investigation I have undertaken on two groups of patients, one of which received propanidid 7 mg/kg body weight for the induction of anaesthesia, followed by suxamethonium 1 mg/kg; the other group received methohexitone 1 mg/kg followed by suxamethonium 1 mg/kg. Blood samples were taken before induction of anaesthesia and 2 and 4 min after the injection of suxamethonium. There was a significant decrease in plasma potassium in both groups of patients, but the reduction was greater in the group which received propanidid (fig. 1). In addition, it was our subjective impression
ali, I. M., and Dundee, J. W. (1974). Immediate changes in plasma potassium, sodium and chloride induced by intravenous induction agents. Br. J. Anaesth., 46, 929. Fry, E. N. S. (1975). The use of propanidid and lignocaine to reduce suxamethonium fasciculations. Br. J. Anaesth., 47, 723.
(23 methohexitone
Time (min) FIG. 1. Serum potassium measurements in two groups o^ patients (20 in each group) before and 2 and 4 min following induction of anaesthesia with either propanidid 7 mg/kg body weight or methohexitone 1 mg/kg followed by suxamethonium 1 mg/kg. that the incidence and extent of fasciculations were less in the propanidid group than in the methohexitone group. These results differ slightly from those of Bali and Dundee (1974) who found that the reduction in serum potassium, 5 min after induction of anaesthesia, was greater following methohexitone than following propanidid 5 mg/kg. Following propanidid 10 mg/kg, Bali and Dundee noted that the serum potassium was increased at 5 min after induction of anaesthesia. ISTVAN PULAY
Budapest, Hungary
M. HEIFETZ S. DE MYTTENAERE
Haifa, Israel REFERENCES
Albertini, R. E., Harrell, J. H., Kurihara, N., and Moser, K. M. (1974). Arterial hypoxemia induced by fibreoptic bronchoscopy. J.A.M.A., 230, 1666. Credle, W. F., Smiddy, J. F., and Elliot, R. C. (1974). Complications of fiberoptic bronchoscopy. Am. Rev. Respir. Dis., 109, 68. Macnaughton, F. I. (1975). Anaesthesia for fibreoptic bronchoscopy. Br. J. Anaesth. 47, 1219.
Downloaded from http://bja.oxfordjournals.org/ at University of Sussex on August 31, 2015
I I propanidid
ANAESTHESIA FOR FTBREOPTIC BRONCHOSCOPY
Sir,—We have read with interest the article by Macnaughton (1975), and we would like to comment on the direct catheter inflation technique which he used. We have been using the catheter inflation technique for fibreoptic bronchoscopy with good results in patients anaesthetized with methohexitone given by i.v. infusion and paralysed with suxamethonium in an i.v. infusion. Our technique differs from that described by Macnaughton in that we do not use an endotracheal tube for the introduction of the fibreoptic bronchoscope as this leads to an unnecessary increase in the diameter of the instrument, causing an increase in the extent of airway obstruction (Credle, Smiddy and Elliot, 1974; Pierson et al., 1974). The catheter inflation technique is a safe method of ventilation and allows adequate oxygenation, but we believe that some safeguards are necessary. The intratracheal pressure should be monitored continuously to prevent an excessive alveolar pressure. This is accomplished easily by fastening a size 10 Argyle catheter to the inflation catheter by adhesive tape. One end of the catheter projects for 3 cm beyond the inflation catheter while the other is connected to a pressure manometer (fig. 1). The intratracheal pressure should not be allowed to increase above 20 cm H,O. The inflation catheter has two side holes. The distal hole prevents the end of the catheter from coming into direct contact with the trachael mucosa and causing damage. The proximal hole, close to the gun, is a safeguard against the use of excessive pressure. In animal experiments, before we monitored tracheal pressures, fatal capillary pulmonary haemorrhages developed in one dog during the inflation catheter technique. As postoperative hypoxaemia occurs frequently after this technique (Albertini et al., 1974) oxygen should always be given for a few hours in the period after operation.
BRITISH JOURNAL OF ANAESTHESIA
1030
Pierson, D. J., Iseman, M. D., Sutton, F. D., and Zwillich, C. W. (1974). Arterial blood-gas changes in fiberoptic bronchoscopy during mechanical ventilation. Chest, 66, 495.
typical fasciculations following the administration of suxamethonium 1 mg/kg body weight i.v. Thus it appears that (concerning the presence of atypical cholinesterase) the statement "the appearance of fasciculations excludes the presence of this abnormality" (Baraka, 1975) is not valid. J. VlBY MOGENSEN
PRESENCE OF SUXAMETHONIUM FASCICULATTONS I N PATIENTS WITH ATYPICAL PLASMA CHOLINESTERASE
Sir,—I should like to comment on the question of muscle fasciculations following suxamethonium in patients with atypical plasma cholinesterase (Baraka, 1975; Hunter, 1975; Feldman, 1976; Hughes, 1976). The establishment of a Danish Cholinesterase Research Unit in 1973, to which all cases of prolonged apnoea in Denmark are reported, has given me the opportunity to anaesthetize eight patients heterozygous for the normal and atypical enzyme (group 1), four patients homozygous for the atypical enzyme (group 2) and one patient heterozygous for the atypical and fluoride-resistant enzyme (group 3). All the patients were anaesthetized with halothane, nitrous oxide and oxygen. Four patients in group 1, two patients in group 2 and the one patient in group 3 showed
Herlev, Denmark REFERENCES
Baraka, A. (1975). Absence of suxamethonium fasciculations in patients with atypical plasma cholinesterase. Br.J. Anaesth., 47,419. Feldman, S. (1976). Absence of suxamethonium fasciculations in patients with atypical plasma cholinesterase. Br.J. Anaesth., 48, 503. Hughes, R. (1976). Absence of suxamethonium fasciculations in patients with atypical plasma cholinesterase. Br.J. Anaesth., 48, 504. Hunter, J. M. (1975). Absence of suxamethonium fasciculations in patients with atypical plasma cholinesterase. Br.J. Anaesth., 47, 1340.
Downloaded from http://bja.oxfordjournals.org/ at University of Sussex on August 31, 2015
FIG. 1. Catheter inflation equipment attached to fibreoptic bronchoscope.
CORRESPONDENCE PLASMA POTASSIUM AND INDUCTION AGENTS
REFERENCES
Sir,—I was interested to read that the combination of propanidid and suxamethonium was accompanied by significantly less muscle fasciculations than the combination of methohexitone and propanidid (Fry, 1975). Thisfindingmay explain the results of a recent investigation I have undertaken on two groups of patients, one of which received propanidid 7 mg/kg body weight for the induction of anaesthesia, followed by suxamethonium 1 mg/kg; the other group received methohexitone 1 mg/kg followed by suxamethonium 1 mg/kg. Blood samples were taken before induction of anaesthesia and 2 and 4 min after the injection of suxamethonium. There was a significant decrease in plasma potassium in both groups of patients, but the reduction was greater in the group which received propanidid (fig. 1). In addition, it was our subjective impression
ali, I. M., and Dundee, J. W. (1974). Immediate changes in plasma potassium, sodium and chloride induced by intravenous induction agents. Br. J. Anaesth., 46, 929. Fry, E. N. S. (1975). The use of propanidid and lignocaine to reduce suxamethonium fasciculations. Br. J. Anaesth., 47, 723.
(23 methohexitone
Time (min) FIG. 1. Serum potassium measurements in two groups o^ patients (20 in each group) before and 2 and 4 min following induction of anaesthesia with either propanidid 7 mg/kg body weight or methohexitone 1 mg/kg followed by suxamethonium 1 mg/kg. that the incidence and extent of fasciculations were less in the propanidid group than in the methohexitone group. These results differ slightly from those of Bali and Dundee (1974) who found that the reduction in serum potassium, 5 min after induction of anaesthesia, was greater following methohexitone than following propanidid 5 mg/kg. Following propanidid 10 mg/kg, Bali and Dundee noted that the serum potassium was increased at 5 min after induction of anaesthesia. ISTVAN PULAY
Budapest, Hungary
M. HEIFETZ S. DE MYTTENAERE
Haifa, Israel REFERENCES
Albertini, R. E., Harrell, J. H., Kurihara, N., and Moser, K. M. (1974). Arterial hypoxemia induced by fibreoptic bronchoscopy. J.A.M.A., 230, 1666. Credle, W. F., Smiddy, J. F., and Elliot, R. C. (1974). Complications of fiberoptic bronchoscopy. Am. Rev. Respir. Dis., 109, 68. Macnaughton, F. I. (1975). Anaesthesia for fibreoptic bronchoscopy. Br. J. Anaesth. 47, 1219.
Downloaded from http://bja.oxfordjournals.org/ at University of Sussex on August 31, 2015
I I propanidid
ANAESTHESIA FOR FTBREOPTIC BRONCHOSCOPY
Sir,—We have read with interest the article by Macnaughton (1975), and we would like to comment on the direct catheter inflation technique which he used. We have been using the catheter inflation technique for fibreoptic bronchoscopy with good results in patients anaesthetized with methohexitone given by i.v. infusion and paralysed with suxamethonium in an i.v. infusion. Our technique differs from that described by Macnaughton in that we do not use an endotracheal tube for the introduction of the fibreoptic bronchoscope as this leads to an unnecessary increase in the diameter of the instrument, causing an increase in the extent of airway obstruction (Credle, Smiddy and Elliot, 1974; Pierson et al., 1974). The catheter inflation technique is a safe method of ventilation and allows adequate oxygenation, but we believe that some safeguards are necessary. The intratracheal pressure should be monitored continuously to prevent an excessive alveolar pressure. This is accomplished easily by fastening a size 10 Argyle catheter to the inflation catheter by adhesive tape. One end of the catheter projects for 3 cm beyond the inflation catheter while the other is connected to a pressure manometer (fig. 1). The intratracheal pressure should not be allowed to increase above 20 cm H,O. The inflation catheter has two side holes. The distal hole prevents the end of the catheter from coming into direct contact with the trachael mucosa and causing damage. The proximal hole, close to the gun, is a safeguard against the use of excessive pressure. In animal experiments, before we monitored tracheal pressures, fatal capillary pulmonary haemorrhages developed in one dog during the inflation catheter technique. As postoperative hypoxaemia occurs frequently after this technique (Albertini et al., 1974) oxygen should always be given for a few hours in the period after operation.
BRITISH JOURNAL OF ANAESTHESIA
1030
Pierson, D. J., Iseman, M. D., Sutton, F. D., and Zwillich, C. W. (1974). Arterial blood-gas changes in fiberoptic bronchoscopy during mechanical ventilation. Chest, 66, 495.
typical fasciculations following the administration of suxamethonium 1 mg/kg body weight i.v. Thus it appears that (concerning the presence of atypical cholinesterase) the statement "the appearance of fasciculations excludes the presence of this abnormality" (Baraka, 1975) is not valid. J. VlBY MOGENSEN
PRESENCE OF SUXAMETHONIUM FASCICULATTONS I N PATIENTS WITH ATYPICAL PLASMA CHOLINESTERASE
Sir,—I should like to comment on the question of muscle fasciculations following suxamethonium in patients with atypical plasma cholinesterase (Baraka, 1975; Hunter, 1975; Feldman, 1976; Hughes, 1976). The establishment of a Danish Cholinesterase Research Unit in 1973, to which all cases of prolonged apnoea in Denmark are reported, has given me the opportunity to anaesthetize eight patients heterozygous for the normal and atypical enzyme (group 1), four patients homozygous for the atypical enzyme (group 2) and one patient heterozygous for the atypical and fluoride-resistant enzyme (group 3). All the patients were anaesthetized with halothane, nitrous oxide and oxygen. Four patients in group 1, two patients in group 2 and the one patient in group 3 showed
Herlev, Denmark REFERENCES
Baraka, A. (1975). Absence of suxamethonium fasciculations in patients with atypical plasma cholinesterase. Br.J. Anaesth., 47,419. Feldman, S. (1976). Absence of suxamethonium fasciculations in patients with atypical plasma cholinesterase. Br.J. Anaesth., 48, 503. Hughes, R. (1976). Absence of suxamethonium fasciculations in patients with atypical plasma cholinesterase. Br.J. Anaesth., 48, 504. Hunter, J. M. (1975). Absence of suxamethonium fasciculations in patients with atypical plasma cholinesterase. Br.J. Anaesth., 47, 1340.
Downloaded from http://bja.oxfordjournals.org/ at University of Sussex on August 31, 2015
FIG. 1. Catheter inflation equipment attached to fibreoptic bronchoscope.
