EFFECT OF TOPICAL LIGNOCAINE ON THE SYMPATHODRENAL RESPONSES TO TRACHEAL INTUBATION

Transcription

1 Br. J. Anaesth. (1987), 59, EFFECT OF TOPICAL LIGNOCAINE ON THE SYMPATHODRENAL RESPONSES TO TRACHEAL INTUBATION D. R. DERBYSHIRE, G. SMITH AND K. J. ACHOLA Hypertenson and tachycarda assocated wth laryngoscopy and trachea! ntubaton are well recognzed, and a good correlaton has been demonstrated between the pressor response and changes n plasma catecholamne concentratons (Russell et al?, 1981; Derbyshre et al., 1983). Lgnocane appled topcally to the oropharynx has been shown to amelorate the pressor response to laryngoscopy when gven 5-10 mn n advance of the manoeuvre and lgnocane, appled ntratracheally mmedately before ntubaton, has been shown to reduce the addtonal pressor component whch accompaned the nserton of the tracheal tube (Denlnger, Ellson and Omnsky, 1974; Stoeltng, 1977). However, n both of these studes, the technque of nducton of anaesthesa wth tracheal ntubaton dd not emulate conventonal clncal practce. Furthermore, no measurements were recorded of the changes n plasma catecholamne concentratons observatons whch mght be helpful n determnng whether or not any benefcal effect of lgnocane results from the surface analgesa or systemc absorpton. The object of the present study was to compare the changes n cardovascular varables and catecholamne concentratons whch were assocated wth a conventonal technque of nducton of anaesthesa and tracheal ntubaton wth and wthout the applcaton of topcal lgnocane to the mucosa of the upper arway. At the same tme, the opportunty was taken to examne the effcency of delvery of lgnocane from a commercally avalable spray, the Laryng-o-jet. D. R. DERBYSHIRE, M.B., BJ., F.F-A.R.OS., Department of Anaesthesa, Warwck General Hosptal, Warwck. G. SMITH, BJC, MJ)., F.F.A.R.CS.; K. J. ACHOLA, M.SC.; Unversty Department of Anaesthesa, Lecester Royal Infrmary, Lecester LEl 5WW. Accepted for Publcaton: July 24,1986. SUMMARY The catecholamne and cardovascular responses to faryngoscopy and trachea/ ntubaton have been studed n 30 patents undergong electve gynaecologcal surgery, allocated randomly to one of three groups: group 1 receved 4% lgnocane 160mg usng a Forrester Spray; group 2 receved 4% lgnocane 160 mg by "Laryng-o-jet"; group 3 receved an equal volume of salne admnstered by Forrester Spray. In all three groups, there were smlar and statstcally sgnfcant ncreases n mean arteral pressure and plasma adrenalne and noradrenalne concentratons 1 mn after ntubaton, wth dmnuton of these responses by 5 mn after ntubaton. There were no dfferences between the three groups at any stage, whch suggests that topcal anaesthesa of the mucosa of the upper arway, as performed conventonally, s neffectve as a means of ameloratng the pressor and catecholamne responses to routne laryngoscopy and ntubaton. PATIENTS AND METHODS Thrty otherwse healthy women about to undergo electve gynaecologcal surgery for whch tracheal ntubaton would normally be used, gave nformed consent for the study, whch was approved by the Dstrct Ethcal Commttee. The patents were randomly allocated to one of three groups. Group 1 receved topcal laryngeal and tracheal lgnocane (160 mg as 4%) delvered from a conventonal Forrester spray: group 2 receved 4% lgnocane 160 mg from a propretary devce (Laryng-o-Jet, Internatonal Medcaton Systems Ltd); group 3 (control group) receved 0.9% sodum chlorde 4 ml to the larynx and trachea delvered from a Forrester spray.

2 RESPONSES TO LARYNGOSCOPY AND INTUBATION 301 Premedcaton comprsed lorazepam 2 mg and metoclopramde 10 mg admnstered 90 mn before anaesthesa. In the anaesthetc room a large ven n the antecubtal fossa was cannulated under local analgesa and, after several mnutes, a sample of venous blood (10 ml) was taken to permt measurement of plasma catecholamne concentratons. Systemc arteral pressure and heart rate were measured (Dnamap 845). Anaesthesa was nduced wth papaveretum 10 mg and 2.5% thopentone S-Smgkg" 1. Atracurum mg kg" 1 was admnstered to provde neuromuscular blockade. Anaesthesa was mantaned subsequently wth 67% ntrous oxde n oxygen supplemented wth 0.2% enflurane admnstered through a Ban breathng system delverng ml kg" 1 fresh gas flow. One mnute after nducton (assessed by loss of eyelash reflex), a further sample of venous blood was obtaned, and heart rate and arteral pressure determned. Immedately afterwards, laryngoscopy was performed usng a Macntosh blade and the predetermned spray was appled to the larynx, trachea and laryngopharynx. The laryngoscope was then wthdrawn; 1 mn later laryngoscopy and tracheal ntubaton were performed, and 1 and 5 mn after ntubaton further samples of blood, and measurements of arteral pressure and heart rate, were obtaned. Surgery then proceeded normally. Venous blood samples for the measurement of plasma catecholamne concentratons were handled dfferently from our usual practce (Derbyshre et al., 1983). All samples were collected nto lthum heparn tubes and plasma was separated at 4000 rev mn" 1 wthn 15 mn. The supernatant was stored at 4 C for up to 3 h before beng frozen at less than 18 C before transfer to Lecester, where storage was mantaned at 70 C untl analyss usng hgh pressure lqud TABLE I. Patent data (mean±sem) Group Age (yr) Weght (kg) Thopentone (mg kg" 1 ) Atracurum (mg kg" 1 ) Forrester + LA Laryng-o-Jet (» = 10) Forrester + salne (n - 10) 35(4) 35(3) 38(3) 63(2) 60(2) 59(2) 4.4(0.2) 4.8(0.2) 5 (0.2) Ch "5 100 E _ 80 a a ID 20 -o Forrester + salne a-a Forrester* lgnocane - Laryng-o-Jet Control 1mn after 1mn 5 mn nducton After ntubaton FIG. 1. Mean arteral pressures (mean±sem) n the three groups, n = 10 n each group.

3 302 chromatography wth electrochemcal detecton as descrbed n our prevous publcaton (Derbyshre et al., 1983). Data were analysed usng pared and unpared Student's t tests, as approprate. RESULTS There were no sgnfcant dfferences between the groups n respect of age, weght or doses of drugs used at the nducton of anaesthesa (table I). Followng the nducton of anaesthesa, there were smlar and sgnfcant decreases n mean arteral pressure n all three groups (20%, 17% and 18% n groups 1, 2 and 3, respectvely) (fg. 1). Heart rates were ncreased by 25, 9, and 13%, n the three groups respectvely (table II). One mnute after tracheal ntubaton, there were BRITISH JOURNAL OF ANAESTHESIA comparable and sgfcant ncreases n mean arteral pressure (43%, 33% and 35% n groups 1, 2 and 3, respectvely). Heart rates ncreased sgnfcantly over control values by 35, 17 and 18% after ntubaton. Fve mnutes after ntubaton, mean arteral pressures and heart rates were smlar to ther control values. These cardovascular changes were accompaned by smlar changes n plasma catecholamne concentratons (fgs 2 and 3). Followng tracheal ntubaton, there were ncreases of 43%, 50% and 44% (groups 1, 2 and 3) n plasma noradrenalne concentratons, and 100%, 75% and 40 % (ns) ncreases n plasma adrenalne concentratons n groups 1, 2 and 3, respectvely. There were no sgnfcant dfferences between the three groups n arteral pressures, heart rates or plasma catecholamne concentratons at any perod of the study. TABLE II. Change n heart rate n three groups of patents (mean ± SEM) Forrester + LA («= 10) Laryng-o-jet Forrester + salne Control After ntubaton After ndue. 1 mn 1 mn 5 mn 79.3± ± ± ± ± ± ± ± ± ± ± ± Forrester* salne Forrester t lgnocane Laryng-o-Jet I 1 Control 1mn after 1mn 5mn nducton After ntubaton FIG. 2. Plasma noradrenalnc concentratons (mean± SEM) n the three groups, n = 10 n each group.

4 RESPONSES TO LARYNGOSCOPY AND INTUBATION 030 O Forrester + salne ~ 0B0 ^ Forrester + lgnocane S Laryng-o-Jet o ~ 0.60 c u 0.50 ID c IS "g Control 1mn after 1mn 5mm nducton After ntubaton FIG. 3. Plasma adrenalne concentratons (mean ± SEM) n the three groups, n = 10 n each group. DISCUSSION Ths study has faled to demonstrate that the pror applcaton of topcal analgesa wth lgnocane to the upper arway mmedately before ntubaton of the trachea modfes the subsequent pressor or sympathoadrenal responses. In ths respect, the fndngs would appear to be at varance wth the study of Denlnger, Ellson and Omnsky (1974) and that of Stoeltng (1977). However, there are rhportant dfferences between the desgn of these studes and the present ones. In the study by Denlnger, Ellson and Omnsky (1974), the desgn of the nvestgaton was as follows: n patents undergong cardac surgery, anaesthetzed wth morphne 1 mg kg" 1 and ntrous oxde n oxygen, tubocurarne and suxamethonum, an ntal laryngoscopy and tracheal spray wth lgnocane was accompaned by a smaller ncrease n arteral pressure 1-5 mn afterwards than occurred n a second group of patents n whom salne was used n place of lgnocane. Fve mnutes later, laryngoscopy and ntubaton were performed and n the salne-treated group the ncrease n pressure was greatly exaggerated, whlst the ncrease n pressure n the lgnocanetreated group was the same as that followng the ntal laryngoscopy and tracheal spray. Ths suggests that tracheal ntubaton s accompaned by sympathoadrenal stmulaton addtonal to that of laryngoscopy alone, and that ths addtonal stmulus may be blocked by ntra-tracheal spray wth lgnocane 120 mg 70 kg" 1, allowng 5 mn for surface analgesa to take effect. The dfference n response between the two groups followng the ntal laryngoscopy can be accounted for only on the grounds that the two groups of patents were not drawn from the same populaton or that absorpton of lgnocane occurred, resultng n subsequent myocardal depresson. Stoeltng (1977) nvestgated several aspects of ths topc n patents premedcated wth morphne 8-15 mg and hyoscne 0.4 mg and anaesthetzed wth thamylal 4 mg kg" 1. Suxamethonum 2 mg kg" 1 and tubocurarne 40 ug kg" 1 were admnstered also. By varyng the duraton of laryngoscopy, t was shown that the pressure response ncreased progressvely over 45 s of contnuous stmulaton and that a further 15 s of laryngoscopy caused lttle addtonal stmulaton. In addton, t was shown that oropharyngeal garglng wth lgnocane 500 mg 10 mn before the nducton of anaesthesa was almost equally as effectve as lgnocane 1.5 mg kg" 1 gven.v. 90 s before laryngoscopy. In patents gven laryngeal spray wth lgnocane 2 mg kg" 1, there was no further sgnfcant ncrease n pressure when tracheal ntubaton was performed after 60 s of laryngoscopy, although there was a sgnfcant ncrease n the group gven lgnocane.v. Ths suggests that the response to laryngoscopy s dependent on the duraton of laryngoscopy, reachng a maxmum at approxmately 45 s, and that tracheal ntubaton offers a further addtonal

5 304 stmulaton. The response of the former may be attenuated, but not abolshed, by the oropharyngeal admnstraton of lgnocane although t s not possble to exclude, n ths study, an effect from the systemc absorpton of lgnocane. In addton, t suggests that the mmedate tracheal applcaton of lgnocane should attenuate the pressor response resultng from the placement of the tracheal tube. The nvestgaton reported n the accompanyng paper (Shrbman, Smth and Achola, 1987) also suggests that most of the sympathoadrenal response to tracheal ntubaton results from laryngoscopy alone. However, the anaesthetc technque dffered slghtly from that used n the present nvestgaton. It s possble to nterpret the negatve fndngs of the present study on the followng grounds. Applcaton of topcal lgnocane would be expected to affect only the addtonal stmulaton resultng from ntubaton of the trachea, whch would be expected to be extremely small n the present study n relatonshp to that produced by laryngoscopy (Shrbman, Smth and Achola, 1987). In addton, the use of enflurane n the mantenance of anaesthesa could result n suppresson of any potental addtonal small stmulus from ntubaton. The anaesthetc sequence used here was one whch mght be used n everyday clncal practce. It s a popular msconcepton that laryngotracheal lgnocane s benefcal: "The value...of lgnocane just before tracheal ntubaton was demonstrated by the mnmal addtonal MAP ncreases..." (Stoeltng, 1977). "The laryngeal reflex can be subdued f [local] analgesc soluton s sprayed onto... the cords..." (Atknson, Rushman and Lee, 1982). However, the present study suggests that, n terms of reducng the sympathoadrenal responses wth conventonal anaesthesa, the manoeuvre s neffectve n respect of laryngoscopy and ntubaton. It has been shown prevously that.v. lgnocane reduces the pressor response to ntubaton (Stoeltng, 1977; Hamll et al., 1981). It s lkely that ths ameloraton occurs as a result of drect myocardal depresson (Thomas, 1975; Rtche and Green, 1980) or the deepenng of anaesthesa. Furthermore, t s well known that topcally appled lgnocane s absorbed systemcally, but there s dspute on whether or not peak serum concentratons occur at 5 mn (Pelton et al., 1970) or later (Chu et al., 1975) followng applcaton of topcal lgnocane to the upper arway. BRITISH JOURNAL OF ANAESTHESIA The Laryng-o-jet s a convenent devce for the admnstraton of topcal lgnocane, for t allows more rapd admnstraton. It mght have been expected from the study of Stoeltng (1977) that ths reducton n the duraton of laryngoscopy, when compared wth the tme requred usng the Forrester spray (flled twce), mght have yelded beneft. Unfortunately, we dd not measure "spray tme", or the total duraton of laryngoscopy, but there s no doubt that ths was shortest n the Laryng-o-jet group. However, we dd not demonstrate any advantage from the shorter duraton of laryngoscopy, although ths mght be accounted for agan by the dfferent anaesthetc technques used n the present study and that of Stoeltng (1977). In concluson, we have faled to demonstrate any benefcal effect of sprayng the cords and upper arway wth 4 % lgnocane n terms of the subsequent pressor response to ntubaton. Before ths concluson may be extrapolated elsewhere, care must be taken to defne the technque of anaesthesa used and the duraton of laryngoscopy. REFERENCES Atknson, R. S., Rushman, G. B., and Lee, A. J. (1982). A Synopss of Anaesthesa. London: Wrght. Chu, S. S., Rah, K. H., Brannan, M. D., and Cohen, J. L. (1975). Plasma concentraton of ldocane after endotracheal spray. Anesth. Analg., 54, 438. Dcnlnger, K. J., Ellson, N., and Omnsky, A. J. (1974). Effects of ntratracheal ldocane on crculatory responses to tracheal ntubaton. Anesthesology, 41, 409. Derbyshre, D. R., Chmelewsk, A., Fell, D., Vater, M., Achola, K. J., and Smth, G. (1983). Plasma catecholamne responses to tracheal ntubaton. Br. J. Anaesth., 55, 855. Hamll, J. R., Bedford, R. F., Weaver, D. C, and Colohan, A. R. (1981). Ldocane before endotracheal ntubaton: ntravenous or laryngotracheal? Anesthesology, 55, 578. Pelton, D. A., Daly, M., Cooper, P. D., and Conn, A. W. (1970). Plasma ldocane concentratons followng topcal aerosol applcaton of local anaesthesa to the trachea and bronch. Can. Anaesth. Soc. J., 17, 250. Rtche, M. J., and Greene, N. M. (1980). In Pharmacologcal Bass of Therapeutcs, Sxth Edn (eds S. Goodman and A. Glman), p London: Ballere Tndall. Russell, W. J., Morrs, R. G., Frewn, D. B., and Drew, S. E. (1981). Changes n plasma catecholamne concentraton durng endotracheal ntubaton. Br. J. Anaesth., 53, 837. Shrbman, A. J., Smth, G., and Achola, K. J. (1987). Cardovascular and catecholamne responses to laryngoscopy wth and wthout tracheal ntubaton. Br.J. Anaesth., 59, 295. Stoeltng, R. K. (1977). Crculatory changes durng drect laryngoscopy and tracheal ntubaton: nfluence of duraton of laryngoscopy wth or wthout pror ldocane. Anesthesology, 47,381. Thomas, D. V. (1975). Intratracheal ldocane local anaesthesa or drect cardac effect? Anesthesology, 42, 517.