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CONTINUOUS SUXAMETHONIUM INFUSION FOR MICROLARYNGEAL SURGERY
Br.J. Anaesth. (1982), 54, 11
CONTINUOUS SUXAMETHONIUM INFUSION FOR MICROLARYNGEAL SURGERY
r
J. CARNIE
SUMMARY
s
r
Suxamethonium provides suitable conditions for laryngoscopy (AH and Savarese, 1976) and for microlaryngeal surgery (Rajagopolan, FosterSmith and Ramachandran, 1972; Vourc'h, Tannieres and Freche, 1979). In particular, sudden patient movement is minimized, resulting in greater safety when instruments such as the carbon dioxide laser are used. The necessity for absolute immobility has been stressed previously (Snow et al., 1974; Vourc'h, Tannieres and Freche, 1979). Continuous suxamethonium infusion has been described on many occasions (Foldes et al., 1952; Churchill-Davidson, Christie and Wise, 1960; Carden and Vest, 1974; Konchigen and Shaker, 1974; Lee, Barnes and Katz, 1978). However, neuromuscular block has not been monitored continuously throughout the entire surgical procedure. Previous studies, involving a lesser degree of neuromuscular blockade, have established that there is poor correlation between the observed twitch response in the hand, and laryngeal paralysis (Bennet, Giesel and Dalai, 1973) or paralysis of the abdominal muscles during abdominal surgery (Crul et al., 1966); 95% twitch depression of the hand muscle response was associated with incomplete cord paralysis (Donlon, AH and Savarese, 1974). A study was undertaken to determine the suxamethonium infusion requirements to maintain neuromuscular blockade of 100% twitch
suppression and to determine if the use of the peripheral nerve stimulator afforded good control of the block. METHODS
Sixteen consecutive patients aged 32-71 yr, undergoing elective microlaryngeal surgery for non-malignant conditions were studied. Patients with malignant disease, liver disease and neurological disease were excluded. An appropriate Kleinsasser suspension laryngoscope was used in all operations, and in eight a carbon dioxide laser was used. Standardized preoperative medication of morphine 5-15 mg and hyoscine was used. Anaesthesia was induced with sodium thiopentone S-Smgkg" 1 , after the i.v. injection of atropine 0.5 mg and pancuronium 1 mg. The ulnar nerve was stimulated at the wrist using surface electrodes and a Myotest train-offour nerve stimulator (Biometer, Odense, Denmark) in the continuous mode. The necessary supramaximal stimulus was determined for each patient with the hand optimally positioned. Tetanic stimulation was never used. Train-offour stimulation aided visual estimation of the evoked thumb response by providing potentially, four distinct movements. Tracheal intubation using a Portex 5-mm endotracheal tube was facilitated by suxamethonium chloride lmgkg" 1 . Anaesthesia was maintained with halothane 0.5-1% and 33% oxygen in JOHN CARNIE, M.B., CH.B.(EDIN.), F F.A R.C.S (LOND.), Anaesthetic Department, Regionsiukhuset, S 58185 nitrous oxide; the lungs were ventilated mechanically by an AGA pneumatic ventilator Linkoping, Sweden. 0007-0912/82/010011-04 S01.00
© Macmillan Publishers Ltd 1982
Downloaded from http://bja.oxfordjournals.org/ at University of Manitoba on September 1, 2015
The suxamethomum infusion requirements to maintain a 100% ncuromuscular block in patients undergoing microlaryngeal surgery were determined. Anaesthesia was maintained with halothane and the neuromuscular block monitored with a peripheral nerve stimulator delivering train-of-four stimuli Suxamethomum requirements varied directly with time in a linear manner and the onset and recovery time of the block increased with time. No difficulties in recovery were observed when the duration of infusion was less than 1 h, even when the nature of the block had altered to the non-depolarizing type. A good correlation was observed between neuromuscular block as indicated by peripheral nerve stimulation and laryngeal muscle paralysis.
BRITISH JOURNAL OF ANAESTHESIA
12
when there was no evidence of any significant residual block (Murphy et al., 1975). RESULTS
The duration of surgery was 18—70 min (mean 34 min). The total dose of suxamethonium infused varied between 0.5 and 6.9mgkg~1 (mean 2.8), being given over a period of 8-60 min (mean 28). Ten patients received more than 3mgkg~'. The dose of suxamethonium required to maintain 100% paralysis was found to be linear with respect to time (fig. 1). Using a least-squares regression line constructed from the data, the dose requirement was found to conform to 0.1 mgkg" 1 min" 1 , with 95% confidence limits of 0.06-0.14mgkg~1min~1. No relationship was observed between the duration of paralysis resulting from the initial dose of suxamethonium at induction and subsequent dosage requirements. On discontinuing the infusion, a marked fade was observed in the train-of-four evoked twitch
2
3
in
1 0
20
30
40
50
60
Tune (mm)
FIG. 1. Each patient's total suxamethomum requirements for the duration of the infusion The time axis starts from observation of the first recovery twitch response after the initial induction dose of suxamethonium.
Downloaded from http://bja.oxfordjournals.org/ at University of Manitoba on September 1, 2015
delivering a tidal volume of 10 ml kg ', at a frequency of 12b.p.m. On reappearance of thumb movement, an i.v. infusion of suxamethomum chloride 2 mg ml" ! in 5% dextrose was commenced in the arm opposite to that stimulated. The rate of infusion was regulated to abolish the observed twitch response. Barely visible twitch movement in the hand is reported to indicate 95—98% twitch depression (Lee, 1975a; Ah and Savarese, 1976). If signs of block recovery were absent after 5 min, the infusion rate was reduced. Any patient who had not demonstrated recovery within the next 5 min would have been excluded from the study; however, this did not prove to be necessary. By these means it was hoped to maintain a 100% block without gross error in dosage. On completion of surgery, the infusion was discontinued and halothane withdrawn. Lignocaine was used to anaesthetize the larynx under direct vision. The tracheal tube was removed when it was judged clinically appropriate and
CONTINUOUS SUXAMETHONIUM FOR MICROLARYNGEAL SURGERY
DISCUSSION
In contrast to previous studies (Crul et al., 1966; Bennet, Giesel and Dalai, 1973) good correlation was found between the observed twitch response and muscle paralysis at the site of operation. A change in behaviour of the neuromuscular block was observed with no overall change in dose required. Several studies using a lesser degree of block or constant dose infusion have demonstrated the changing nature of the resulting neuromuscular block, with two steady-state periods, corresponding to type I and type II block, with a brief period of tachyphylaxis separating the two (Lee, 1975b; Lee, Barnes and Katz, 1978). The use of train-of-four stimuli was supported by the finding that the majority of patients required a dose in excess of Smgkg" 1 , a dose found in previous studies to be associated with a well established Phase II block (Lee, 1975b; Lee, Barnes and Katz, 1978). This study also demonstrated a satisfactory speed of recovery of the neuromuscular block when the infusion period was limited to 1 h as shown by Katz and Ryan (1969). The use of such an infusion was not associated with the occurrence of any undesirable clinical features in the patients studied.
REFERENCES
All, H., and Savarese, J. J. (1976). Monitoring of neuromuscular function. Anestheswlogy, 45, 216.
Bennet, E. J., Giesel, G. S., and Dalai, F Y (1973). Pancuronium bromide a double-blind, comparison with DTC for intubation in adults Arusth Analg (Cine.), 52, 195 Carden, E , and Vest, H. (1974). Further advances in anesthetic techniques for surgery. Anesth Analg. (Cleve ) , 53, 584. Churchill-Davidson, H. C , Christie, T. H , and Wise, R P. (1960). Dual neuromuscular block in man Anestheswlogy, 21, 144. Crul, J , Long, G , Brunner, A., and Coolen, J (1966). The changing pattern of neuromuscular blockade caused by succinylchohne in man. Anesthestology, 27, 729 Donlon, J V., Ah, H , and Savarese, J. J (1974). A new approach to the study of four non-depolansing relaxants in man. Anesth. Analg (Cleve ) , 53, 934. Foldes, F. F., McNall, P. G , Lehman, H , Silk, E (1952). Succinylcholine, a new approach to muscular relaxation in anestheswlogy. N Engl J. Med., 247, 596 Kat2, R. L , and Ryan, J F. (1969) The neuromuscular effects of suxamethonium in man Br. J. Anaesth , 41, 381 Konchigen, H., and Shaker, M (1974) Anaesthesia for intralaryngeal laser surgery Can. Anaesth Soc J., 21, 343. Lee, C. (1975a) Train-of-four quantitation of competitive neuromuscular block. Anesth Analg. (Cleve.), 54, 649 (1975b) Dose relationships of phase II ttchyphylaxis and train-of-four fade in suxamethowum-induced dual neuromuscular block in man Br. J. Anaesth , 47, 841. Barnes, A , and Katz, R. L. (1978). Magnitude, dose requirement and mode of development of tachyphylaxis to suxamethonium in man Br J. Anaesth., 50, 189. Murphy, J , Padgett, C , Lee, C , and Ponitz, J. (1975) Trainof-four stimulation in the management of prolonged neuromuscular blockade following succinylcholine Anesthestology, 42, 106.
Rajagopolan, R , Foster-Smith, and Ramachandran, P. R (1972). Anaesthesia for microlaryngoscopy and definitive surgery Can. Anaesth J., 19, 83. Snow, J., Knpke, B., Strong, M., Jako, G , Meyer, M , and Vaughan, C. (1974). Anesthesia for carbon dioxide laser microsurgery on the larynx and trachea Anesth. Analg. (Cleve ) , 53, 507 Vourc'h, G., Tannieres, M L., and Freche, G. (1979) Anaesthesia for microsurgery of the larynx using a carbon dioxide laser. Anaesthesia, 34, 53 PERFUSION CONTINUE DE SUXAMETHONIUM POUR LES INTERVENTIONS CHIRURGICALES MICROLARYNGIENNES RESUME
Nous avons determine les pnncipcs regissant la perfusion de suxamethonium pour entretenir un blocage neuromusculaire a 100% sur des patients subissant une intervention chirurgicale rrucrolaryngienne. L'anesthesie a ete entretenue a l'aide d'halothane et le blocage neuromusculaire a ete surveille a l'aide d'une dispositif electrique de stimulation du nerf penphenque produisant des stimulations par chaine de quatre. Les exigences du suxamethonium ont vane d'une maniere lineaire directement avec le temps, et le temps compris entre le depart et la recuperation du blocage a augmente avec le temps. On n'a observe aucune difficulte dans la reprise de conscience
Downloaded from http://bja.oxfordjournals.org/ at University of Manitoba on September 1, 2015
responses in eight patients; each had received at least Smgkg" 1 of suxamethonium. The interval between stopping the infusion and tracheal extubation ranged from 3 to 16min (mean 9). No significant airway or respiratory problems were encountered after operation. During surgery the observed thumb response provided a reliable indication of laryngeal movement. In the majority of patients the surgeon indicated resumption of minimal cord movement immediately before the return of thumb movement. After a period of time, a difference in speed of onset of recovery and in attaining control of the block was noted. Initially there was a rapid recovery with a corresponding rapidity of control but, as the infusion continued, the converse was noted.
13
BRITISH JOURNAL OF ANAESTHESIA
14 lorsque la duree de la perfusion a etc inferieure a 1 h, meme lorsque la nature du blocage s'etait modifiee pour devenir du type non depolanxant. On a constate une bonne correlation entre le blocage neuromusculaire, comme cela a ete indique par la stimulation du nerf penphcnquc et la paralysie du muscle laryngien. KONTINUIERLICHE SUXAMETHONIUMINFUSION BEI KEHLKOPFMIKROCHIRURGIE ZUSAMMENFASSUNG
INFUSION CONTINUA DE SUXAMETONIO PARA LA MICROCIRUJIA LARINGEAL SOMARIO
Se determinaron los requisitos de la infusion de suxametonio para mantener un bloqueo neuromuscular del 100°o en pacientes sometidos a microcirujia de la laringe. La anesthesia se mantuvo con haltano y el bloqueo neuromuscular se vigilo con un estimulador de nervio penfenco que entregaba estimulo en trcnes de cuatro impulses Los requisitos de suxamctoruo vanaron linealmente y de forma directa en el transcurso del uempo, y el uempo de micio y de recuperacion del bloqueo aumentaron con el tiempo No se observaron dificultades en la recuperacion cuando la duracion de la infusion fue inferior a una hora, incluso cuando la naturaleza del bloqueo se altero convirtiendose en el tipo no despolanzante Se observo una buena correlacion entre el bloqueo neuromuscular, tal y como se indico por la estimulacion del nervio penfenco y por la parahsis del musculo lanngcal
Downloaded from http://bja.oxfordjournals.org/ at University of Manitoba on September 1, 2015
Es wurde die Suxamethonium-Infusionsmenge bestimmt, die zur Untcrstutzung einer 100",,-igen neuromuskularen Blockade bei Kehlkopfmikrochirurgie erforderlich ware. Die Anasthesie wurde mittels Halothan fortgefuhrt und die neuromuskulare Blockade wurde mit einem penpheren Nervenstimulator uberwacht, der Viererzug-Reizimpulse lieferte Die Suxamethoniumforderungen anderten sich direkt in linearer Weise mit der Zeit und das Einsetzen der Blockade und die Erholungszeit stiegen mit der Zeit Bei ciner Infusionsdauer von weniger als einer Stunde wurden keinerlei Schwierigkeiten bei der Erholung beobachtet, selbst dann nicht, als die
Blockade sich in erne nicht-depolansierende gewandelt hatte Es wurde eine gute Korrelation zwischen der durch periphere Nervenstimulauon ausgewiesenen neuromuskularen Blockade und der Kehlkopfmuskellahmung beobachtet
CONTINUOUS SUXAMETHONIUM INFUSION FOR MICROLARYNGEAL SURGERY
r
J. CARNIE
SUMMARY
s
r
Suxamethonium provides suitable conditions for laryngoscopy (AH and Savarese, 1976) and for microlaryngeal surgery (Rajagopolan, FosterSmith and Ramachandran, 1972; Vourc'h, Tannieres and Freche, 1979). In particular, sudden patient movement is minimized, resulting in greater safety when instruments such as the carbon dioxide laser are used. The necessity for absolute immobility has been stressed previously (Snow et al., 1974; Vourc'h, Tannieres and Freche, 1979). Continuous suxamethonium infusion has been described on many occasions (Foldes et al., 1952; Churchill-Davidson, Christie and Wise, 1960; Carden and Vest, 1974; Konchigen and Shaker, 1974; Lee, Barnes and Katz, 1978). However, neuromuscular block has not been monitored continuously throughout the entire surgical procedure. Previous studies, involving a lesser degree of neuromuscular blockade, have established that there is poor correlation between the observed twitch response in the hand, and laryngeal paralysis (Bennet, Giesel and Dalai, 1973) or paralysis of the abdominal muscles during abdominal surgery (Crul et al., 1966); 95% twitch depression of the hand muscle response was associated with incomplete cord paralysis (Donlon, AH and Savarese, 1974). A study was undertaken to determine the suxamethonium infusion requirements to maintain neuromuscular blockade of 100% twitch
suppression and to determine if the use of the peripheral nerve stimulator afforded good control of the block. METHODS
Sixteen consecutive patients aged 32-71 yr, undergoing elective microlaryngeal surgery for non-malignant conditions were studied. Patients with malignant disease, liver disease and neurological disease were excluded. An appropriate Kleinsasser suspension laryngoscope was used in all operations, and in eight a carbon dioxide laser was used. Standardized preoperative medication of morphine 5-15 mg and hyoscine was used. Anaesthesia was induced with sodium thiopentone S-Smgkg" 1 , after the i.v. injection of atropine 0.5 mg and pancuronium 1 mg. The ulnar nerve was stimulated at the wrist using surface electrodes and a Myotest train-offour nerve stimulator (Biometer, Odense, Denmark) in the continuous mode. The necessary supramaximal stimulus was determined for each patient with the hand optimally positioned. Tetanic stimulation was never used. Train-offour stimulation aided visual estimation of the evoked thumb response by providing potentially, four distinct movements. Tracheal intubation using a Portex 5-mm endotracheal tube was facilitated by suxamethonium chloride lmgkg" 1 . Anaesthesia was maintained with halothane 0.5-1% and 33% oxygen in JOHN CARNIE, M.B., CH.B.(EDIN.), F F.A R.C.S (LOND.), Anaesthetic Department, Regionsiukhuset, S 58185 nitrous oxide; the lungs were ventilated mechanically by an AGA pneumatic ventilator Linkoping, Sweden. 0007-0912/82/010011-04 S01.00
© Macmillan Publishers Ltd 1982
Downloaded from http://bja.oxfordjournals.org/ at University of Manitoba on September 1, 2015
The suxamethomum infusion requirements to maintain a 100% ncuromuscular block in patients undergoing microlaryngeal surgery were determined. Anaesthesia was maintained with halothane and the neuromuscular block monitored with a peripheral nerve stimulator delivering train-of-four stimuli Suxamethomum requirements varied directly with time in a linear manner and the onset and recovery time of the block increased with time. No difficulties in recovery were observed when the duration of infusion was less than 1 h, even when the nature of the block had altered to the non-depolarizing type. A good correlation was observed between neuromuscular block as indicated by peripheral nerve stimulation and laryngeal muscle paralysis.
BRITISH JOURNAL OF ANAESTHESIA
12
when there was no evidence of any significant residual block (Murphy et al., 1975). RESULTS
The duration of surgery was 18—70 min (mean 34 min). The total dose of suxamethonium infused varied between 0.5 and 6.9mgkg~1 (mean 2.8), being given over a period of 8-60 min (mean 28). Ten patients received more than 3mgkg~'. The dose of suxamethonium required to maintain 100% paralysis was found to be linear with respect to time (fig. 1). Using a least-squares regression line constructed from the data, the dose requirement was found to conform to 0.1 mgkg" 1 min" 1 , with 95% confidence limits of 0.06-0.14mgkg~1min~1. No relationship was observed between the duration of paralysis resulting from the initial dose of suxamethonium at induction and subsequent dosage requirements. On discontinuing the infusion, a marked fade was observed in the train-of-four evoked twitch
2
3
in
1 0
20
30
40
50
60
Tune (mm)
FIG. 1. Each patient's total suxamethomum requirements for the duration of the infusion The time axis starts from observation of the first recovery twitch response after the initial induction dose of suxamethonium.
Downloaded from http://bja.oxfordjournals.org/ at University of Manitoba on September 1, 2015
delivering a tidal volume of 10 ml kg ', at a frequency of 12b.p.m. On reappearance of thumb movement, an i.v. infusion of suxamethomum chloride 2 mg ml" ! in 5% dextrose was commenced in the arm opposite to that stimulated. The rate of infusion was regulated to abolish the observed twitch response. Barely visible twitch movement in the hand is reported to indicate 95—98% twitch depression (Lee, 1975a; Ah and Savarese, 1976). If signs of block recovery were absent after 5 min, the infusion rate was reduced. Any patient who had not demonstrated recovery within the next 5 min would have been excluded from the study; however, this did not prove to be necessary. By these means it was hoped to maintain a 100% block without gross error in dosage. On completion of surgery, the infusion was discontinued and halothane withdrawn. Lignocaine was used to anaesthetize the larynx under direct vision. The tracheal tube was removed when it was judged clinically appropriate and
CONTINUOUS SUXAMETHONIUM FOR MICROLARYNGEAL SURGERY
DISCUSSION
In contrast to previous studies (Crul et al., 1966; Bennet, Giesel and Dalai, 1973) good correlation was found between the observed twitch response and muscle paralysis at the site of operation. A change in behaviour of the neuromuscular block was observed with no overall change in dose required. Several studies using a lesser degree of block or constant dose infusion have demonstrated the changing nature of the resulting neuromuscular block, with two steady-state periods, corresponding to type I and type II block, with a brief period of tachyphylaxis separating the two (Lee, 1975b; Lee, Barnes and Katz, 1978). The use of train-of-four stimuli was supported by the finding that the majority of patients required a dose in excess of Smgkg" 1 , a dose found in previous studies to be associated with a well established Phase II block (Lee, 1975b; Lee, Barnes and Katz, 1978). This study also demonstrated a satisfactory speed of recovery of the neuromuscular block when the infusion period was limited to 1 h as shown by Katz and Ryan (1969). The use of such an infusion was not associated with the occurrence of any undesirable clinical features in the patients studied.
REFERENCES
All, H., and Savarese, J. J. (1976). Monitoring of neuromuscular function. Anestheswlogy, 45, 216.
Bennet, E. J., Giesel, G. S., and Dalai, F Y (1973). Pancuronium bromide a double-blind, comparison with DTC for intubation in adults Arusth Analg (Cine.), 52, 195 Carden, E , and Vest, H. (1974). Further advances in anesthetic techniques for surgery. Anesth Analg. (Cleve ) , 53, 584. Churchill-Davidson, H. C , Christie, T. H , and Wise, R P. (1960). Dual neuromuscular block in man Anestheswlogy, 21, 144. Crul, J , Long, G , Brunner, A., and Coolen, J (1966). The changing pattern of neuromuscular blockade caused by succinylchohne in man. Anesthestology, 27, 729 Donlon, J V., Ah, H , and Savarese, J. J (1974). A new approach to the study of four non-depolansing relaxants in man. Anesth. Analg (Cleve ) , 53, 934. Foldes, F. F., McNall, P. G , Lehman, H , Silk, E (1952). Succinylcholine, a new approach to muscular relaxation in anestheswlogy. N Engl J. Med., 247, 596 Kat2, R. L , and Ryan, J F. (1969) The neuromuscular effects of suxamethonium in man Br. J. Anaesth , 41, 381 Konchigen, H., and Shaker, M (1974) Anaesthesia for intralaryngeal laser surgery Can. Anaesth Soc J., 21, 343. Lee, C. (1975a) Train-of-four quantitation of competitive neuromuscular block. Anesth Analg. (Cleve.), 54, 649 (1975b) Dose relationships of phase II ttchyphylaxis and train-of-four fade in suxamethowum-induced dual neuromuscular block in man Br. J. Anaesth , 47, 841. Barnes, A , and Katz, R. L. (1978). Magnitude, dose requirement and mode of development of tachyphylaxis to suxamethonium in man Br J. Anaesth., 50, 189. Murphy, J , Padgett, C , Lee, C , and Ponitz, J. (1975) Trainof-four stimulation in the management of prolonged neuromuscular blockade following succinylcholine Anesthestology, 42, 106.
Rajagopolan, R , Foster-Smith, and Ramachandran, P. R (1972). Anaesthesia for microlaryngoscopy and definitive surgery Can. Anaesth J., 19, 83. Snow, J., Knpke, B., Strong, M., Jako, G , Meyer, M , and Vaughan, C. (1974). Anesthesia for carbon dioxide laser microsurgery on the larynx and trachea Anesth. Analg. (Cleve ) , 53, 507 Vourc'h, G., Tannieres, M L., and Freche, G. (1979) Anaesthesia for microsurgery of the larynx using a carbon dioxide laser. Anaesthesia, 34, 53 PERFUSION CONTINUE DE SUXAMETHONIUM POUR LES INTERVENTIONS CHIRURGICALES MICROLARYNGIENNES RESUME
Nous avons determine les pnncipcs regissant la perfusion de suxamethonium pour entretenir un blocage neuromusculaire a 100% sur des patients subissant une intervention chirurgicale rrucrolaryngienne. L'anesthesie a ete entretenue a l'aide d'halothane et le blocage neuromusculaire a ete surveille a l'aide d'une dispositif electrique de stimulation du nerf penphenque produisant des stimulations par chaine de quatre. Les exigences du suxamethonium ont vane d'une maniere lineaire directement avec le temps, et le temps compris entre le depart et la recuperation du blocage a augmente avec le temps. On n'a observe aucune difficulte dans la reprise de conscience
Downloaded from http://bja.oxfordjournals.org/ at University of Manitoba on September 1, 2015
responses in eight patients; each had received at least Smgkg" 1 of suxamethonium. The interval between stopping the infusion and tracheal extubation ranged from 3 to 16min (mean 9). No significant airway or respiratory problems were encountered after operation. During surgery the observed thumb response provided a reliable indication of laryngeal movement. In the majority of patients the surgeon indicated resumption of minimal cord movement immediately before the return of thumb movement. After a period of time, a difference in speed of onset of recovery and in attaining control of the block was noted. Initially there was a rapid recovery with a corresponding rapidity of control but, as the infusion continued, the converse was noted.
13
BRITISH JOURNAL OF ANAESTHESIA
14 lorsque la duree de la perfusion a etc inferieure a 1 h, meme lorsque la nature du blocage s'etait modifiee pour devenir du type non depolanxant. On a constate une bonne correlation entre le blocage neuromusculaire, comme cela a ete indique par la stimulation du nerf penphcnquc et la paralysie du muscle laryngien. KONTINUIERLICHE SUXAMETHONIUMINFUSION BEI KEHLKOPFMIKROCHIRURGIE ZUSAMMENFASSUNG
INFUSION CONTINUA DE SUXAMETONIO PARA LA MICROCIRUJIA LARINGEAL SOMARIO
Se determinaron los requisitos de la infusion de suxametonio para mantener un bloqueo neuromuscular del 100°o en pacientes sometidos a microcirujia de la laringe. La anesthesia se mantuvo con haltano y el bloqueo neuromuscular se vigilo con un estimulador de nervio penfenco que entregaba estimulo en trcnes de cuatro impulses Los requisitos de suxamctoruo vanaron linealmente y de forma directa en el transcurso del uempo, y el uempo de micio y de recuperacion del bloqueo aumentaron con el tiempo No se observaron dificultades en la recuperacion cuando la duracion de la infusion fue inferior a una hora, incluso cuando la naturaleza del bloqueo se altero convirtiendose en el tipo no despolanzante Se observo una buena correlacion entre el bloqueo neuromuscular, tal y como se indico por la estimulacion del nervio penfenco y por la parahsis del musculo lanngcal
Downloaded from http://bja.oxfordjournals.org/ at University of Manitoba on September 1, 2015
Es wurde die Suxamethonium-Infusionsmenge bestimmt, die zur Untcrstutzung einer 100",,-igen neuromuskularen Blockade bei Kehlkopfmikrochirurgie erforderlich ware. Die Anasthesie wurde mittels Halothan fortgefuhrt und die neuromuskulare Blockade wurde mit einem penpheren Nervenstimulator uberwacht, der Viererzug-Reizimpulse lieferte Die Suxamethoniumforderungen anderten sich direkt in linearer Weise mit der Zeit und das Einsetzen der Blockade und die Erholungszeit stiegen mit der Zeit Bei ciner Infusionsdauer von weniger als einer Stunde wurden keinerlei Schwierigkeiten bei der Erholung beobachtet, selbst dann nicht, als die
Blockade sich in erne nicht-depolansierende gewandelt hatte Es wurde eine gute Korrelation zwischen der durch periphere Nervenstimulauon ausgewiesenen neuromuskularen Blockade und der Kehlkopfmuskellahmung beobachtet