Acta Anaesthesiol Scand 1992: 36: 505-507
Prophylactic laryngo-tracheal aerosolized lidocaine against postoperative sore throat c.
P. HERLEVSEN, BREDAHL, K. HINDSHOLM and P. K. KRUH0FFER Department of Anaesthesia, Aalborg Hospital, Aalborg, Denmark
A randomized, double-blind study was carried out on 193 ASA 1-11 surgical patients to assess the effect of aerosolized lidocaine on sore throat, hoarseness and cough in connection with tracheal intubation. The study group received aerosolized lidocaine 100 mg 2 min before tracheal intubation, using a spray. The control group received no spray. The patients underwent a standardized general anaesthesia. The patients were interviewed when leaving the recovery room and the next day in the ward. Specific questions were asked regarding sore throat, cough and hoarseness. There were no significant differences between the two groups, which suggests that topical anaesthesia of the mucosa of the upper airway is ineffective as a means of ameliorating airway complaints in connection with tracheal intubation.
Received 5 July, accepted for publication 15 November 1991
Key words: Anesthesia: local; topical; intubation: intratracheal, endotracheal; lidocaine.
Tracheal intubation for general anaesthesia often leads to trauma of the airway mucosa, resulting in postoperative sore throat and cough (1). Methods to avoid these airway symptoms have been sought. Endotrachea1 lidocaine sprays are frequently used in clinical practice; however, there has been no evaluation of their effectiveness in reducing postoperative airway complaints. The aim of this study was to establish the effects of the application of aerosolized lidocaine to the mucosa of the upper airway on postoperative sore throat, hoarseness and cough. PATIENTS AND METHODS Two hundred patients, ASA group I and 11, aged 18 to 75 years, scheduled for elective gynaecologic, urologic, orthopaedic or abdominal surgery were studied. Patients requiring a gastric tube were excluded from the study. Informed consent was obtained from each patient, and the study was approved by the local Ethics Committee. The patients were randomly allocated in a double-blind manner to the study group (lidocaine spray (Xylocaine R, ASTRA)) or the control group (no spray)). Double blinding was achieved as follows: on inclusion, each patient was assigned a numbered envelope containing the result of randomisation. The envelope was opened by the anaesthetist and closed again; it was not opened again until the study was finished. Neither the patient nor the interviewer (one of the authors) was notified of the results of randomisation. On inclusion, the patients were informed about which questions were going to be asked and only to answer “yes” or “no” to cough? soreness? or hoarseness? Premedication consited of either diazepam 5-20 mg orally, lorazepam 1.25-2.5 mg orally or pethidine 0.5-1 mg/kg i.m. In the anaesthetic room the patients received atropine 0.5 mg and pethidine 0.5-1 mg/kg or fentanyl 1-2 p/kg. Induction was done with thiopen-
tone 3-5 mg/kg. The lungs were ventilated with 100% oxygen and relaxation was obtained with vecuronium 0.1 mg/kg. For the patients in the study group, after 2 min of mask ventilation, laryngoscopy was performed with a Macintosh blade and the lidocaine spray was applied: 3 sprays on the epiglottis, 3 on the vocal cords and 4 into the trachea. The total dose of lidocaine was 100 mg, as according to the manufacturer each spray contains 10 mg. The laryngoscope was then withdrawn and ventilation was continued for a further 2 min before intubation. For the patients in the control group, laryngoscopy and tracheal intubation were performed after 4 min of ventilation. Soft rubber tracheal tubes (Rusch R), size 9.5 mm inner diameter for males and 8.5 for females, were used, unless the anaesthetist judged that the trachea was too small and demanded a smaller tube. The cuff was inflated until no airleak could be heard. Plastic guedel airways were used, the size was decided by the anaesthetist and not recorded. Anaesthesia then continued with N,O/O, (2: 1) and either halothane or balanced anaesthesia with thiopentone and meperidine or fentanyl. T h e patients who had abdominal surgery and required continued relaxation were relaxed using bolus doses of vecuronium of 1-2 mg. Before extubation all patients received atropine 0.5-1.0 mg and neostigmine 1-2.5 mg. All patients were questioned about sore throat, cough and hoarseness before they left the recovery area, and the next day in the ward.
Statistical analysis The required number of patients was calculated in expectation of 40% with sore throat in the control group, and a reduction to 20% in the study group. Type 1 error was set to 5% and type 2 error to 10%. With this assumption, 100 patients were required in each group. The data are presented using median and 25-75 percentiles. Data on ordinal scale were tested using Mann-Whitney’s test and frequencies were tested using Fisher’s exact test. PC0.05 was considered statistically significant.
RESULTS Of 200 patients included, 7 were excluded because of procedural mistakes. There were no significant differ-
506
P. HERLEVSEN ET AL.
Table I General data on patients intubated after spraying of the upper airway with lidocaine and without spraying (numbers in parenthesis: 25 and 75 percentiles).
n Femalelmale Age Duration intubated (min) Hypotension* (n) Hypotension** (min) Difficult intubation (n)
Premedicalion: Diazepam (n) Lorazepam (n) Meperidine (n) Anaesthesia: Halothane (n) Balanced (meperidine) (n) Balanced (fentanyl) (n)
*
**
Lidocaine spray
No spray
96 30/66 46 (33-59) 95 (70-135) 22 30 (19-50) 5
97 21/76 47 (35-61) 100 (60-145) 16 22 ( I 1-79) 9
43 35 19
43 32 21
25 57 14
29 52 16
Systolic arterial pressure < 75% of preincubation value for more than 5 min. Duration of hypotension.
ences between the two groups with regard to age, sex, kind of premedication and anaesthetics, amount of opioid (premedicated opioids included), length of anaesthesia and intubation, difficulty with intubation (more than one attempt at passage of the tube), or incidence and duration of hypotension (Table 1). Thirty-two patients received a smaller tube in accordance with the anaesthetist’s judgement, 18 in the lidocaine group and 14 in the control group. Table 2 summarizes the incidence of sore throat, cough and hoarseness in our population. There were no significant differences between the two groups at any period of the study, although a trend toward higher incidence of sore throat was seen in the lidocaine group. Patients in both groups had a higher frequency Table 2 Side effects of tracheal intubation in patients intubated after spraying of the upper airway with lidocaine and without spraying (percentage in parenthesis).
n
Day of surgery Sore throat Hoarseness Cough One or more of sore throat, hoarseness or cough Next day Sore throat Cough One or more of sore throat or cough
Lidocaine spray
No spray
96
97
28 (29) 24 (25) 11 (11)
21 (22) 10 (10)
50 (52)
38 (39)
12 (13) 9 (9) 17 (18)
7 (7)
19 (20)
9(9) 13 (13)
of sore throat on the day of surgery as compared to the next day. DISCUSSION Many factors are involved in the aetiology of sore throat and laryngeal lesions following general anaesthesia. The intubation procedure itself (2), and the diameter of the tube are of importance. In a recent study it was shown that the incidence and severity of postoperative sore throat and hoarseness after endotracheal intubation was reduced by the use of smaller tubes (3). The amount of motor activity of laryngeal muscles while the tube is in place is of importance (4),in addition to the movement of the tube (5). A study demonstrated that the use of succinylcholine was related to sore throat, and that nondepolarizing pretreatment reduced the incidence somewhat (from 68 to 45%) (6). It has been shown that the frequency and severity of postoperative sore throat. after intubation were significantly greater after the use of low-pressure, highvolume cuffs (46-65%), than after the use of highpressure, low-volume cuffs (25-52%) (7, 8). Possible explanations may be that tracheal tube cuffs produce tracheal mucosal damage in direct relation to the cufftracheal wall contact area, which is known to be largest when low-pressure, high-volume cuffs are used (7), and furthermore it has been demonstrated, in a histological study, that low-pressure, high-volume cuffs produce grooves in the mucosa because of wrinkling of the cuff as it is inflated, unlike the situation after inflation of high-pressure, low-volume cuffs (9). A study of the shape of the tube led to the conclusion that an endotracheal tube which conforms to the anatomy of the airway, e.g. the Lindholm tube, causes less postoperative sore throat and a milder mucosal reaction in the posterior larynx than an ordinary shaped tube (1). That factors other than intubation trauma per se are involved is demonstrated by the fact that a mask technique is followed by sore throat in 15-18% of patients (8, 10). Possible explanations may be the drying of mucous membranes after ventilation with dry gasses and the use of antisialogogues (7). Different lubricants and anaesthetic agents have been applied to the tube in an attempt ot diminish airway irritation. The results of these studies have differed. It was reported that the incidence of sore throat after lubrication with 4% lignocaine jelly containing polyethylene and propylene glycols was 90%, as compared with 40% after lubrication with saline solution (10). However, it has been shown earlier, that patients
LIDOCAINE, TRACHEAL INTUBATION, SORE THROAT
507
might benefit from lubrication of tracheal tubes with 1% cinchocaine jelly (1 l ) , and Xylocain gel (12). The symptom sore throat may be considered as one of many postoperative airway complaints. In a study on the correlation between airway complaints and laryngeal pathology after intubation, Alexopoulus & Lindholm demonstrated that the main symptom of cuff lesions in the trachea was generally not sore throat, but an irritating cough (1). In keeping with this result, in the present study not only sore throat, but also cough and hoarseness were recorded. One of the probable reasons for the discrepancy between the frequency of discomfort in the airways in many previous investigations is that only sore throat was recorded. Laryngoscopy and tracheal intubation are potent stimuli that increase heart rate and blood pressure. Aerosolized lidocaine is widely used to blunt haemodynamic stimulation during the intubation procedure, although the efficacy of lidocaine treatment in this setting has been questioned (13, 14). The results of this study indicate that administration of lidocaine by aerosol before passage of the endotracheal tube provides no advantage in terms of postoperative sore throat, cough and hoarseness. I n fact, aerosolized lidocaine was associated with a higher incidence of sore throat (29.2%) than no lidocaine (19.6%), although this difference was not statistically significant. This finding suggests that lidocaine may be irritating or damaging to the mucosa of the trachea or upper airway. In conclusion, on the basis of this study, we do not recommend endotracheal lidocaine spray before intubation as a means of preventing the occurrence of postoperative airway complaints.
2. Haxholdt B F. Via falsa ved naso-tracheal intubation. Nord Med 1954: 52: 1589. 3. Stout D M, Bishop M J, DwerstegJ F, Cullen B F. Correlation of endotracheal tube size with sore throat and hoarseness following general anaesthesia. Anesfhesiology 1987: 67: 419-421. 4. Jackson C H. Contact ulcer gramuloma and other laryngeal complications of endotracheal anesthesia. Anesthesiology 1953: 14: 425. 5. Kleinsasser 0. Endotracheakatheter mit beweglicher Abdichtmanschette zur Vermeidung von Wandschadigungen der Luftrohre. Anaesfhesist 1969: 18: 382. 6. Capan L M, Bruce D L, Patel K P, TurndorfH. Succinylcholineinduced postoperative sore throat. Anesthesiology 1983: 59: 202-206. 7. Loeser E A, Orr D L, Bennett G M, Stanley T H. Endotracheal tube cuff design and postoperative sore throat. Anesthesiologr 1976: 45: 684-687. 8. Jensen P J, Hommelgaard P, Sendergaard P, Eriksen S. Sore throat after operation: influence of tracheal intubation, intracuff pressure and type of cuff. Br 3 Anaesth 1982: 54: 453-457. 9. Loeser E A, Hodges M, Gliedman J, Stanley T H, Johansen R K, Yonetani D. Tracheal pathology following short-term intubation with low- and high-pressure endotracheal tube cuffs. Anesth Analg 1978: 57: 577. 10. Loeser E A, Stanley T H, Jordan W, Machin R. Postoperative sore throat: influence of tracheal tube lubrication versus cuff design. Can Anaesth Sot 3 1980: 27: 156. 1 1 . Winkel E, Knudsen J. Effect on the incidence of postoperative sore throat of 2 per cent cinchocaine jelly for endotracheal intubation. Anesfh Analg 1971: 50: 92-94. 12. Lund L 0, Daos F G. Effects of postoperative sore throat of two analgetic agents and lubricants used with endotracheal tubes. Anesthesiology 1965: 26: 681-683. 13. Laurito C E, Baughman V L, Becker G L, Polek W V, Riegler F X, VadeBoncouer T R. Effects of aerosolized and/or intravenous lidocaine on hemodynamic responses to laryngoscopy and intubation in outpatients. Ancsfh Analg 1988: 6 7 389-392. 14. Denlinger J K, Ellison N, Ominsky A J. Effects of intratracheal lidocaine on circulatory responses to tracheal intubation. Anesthesiology 1974 41: 409-412.
REFERENCES
Address: Per Herleusen Purkervej 7 DK-9520 Skorping Denmark
I , Alexopoulos C, Lindholm C-E. Airway complaints and laryngeal pathology after intubation with an anatomically shaped endotracheal tube. Acta Anaesthesiol Scand 1983: 27: 33%344.
Prophylactic laryngo-tracheal aerosolized lidocaine against postoperative sore throat c.
P. HERLEVSEN, BREDAHL, K. HINDSHOLM and P. K. KRUH0FFER Department of Anaesthesia, Aalborg Hospital, Aalborg, Denmark
A randomized, double-blind study was carried out on 193 ASA 1-11 surgical patients to assess the effect of aerosolized lidocaine on sore throat, hoarseness and cough in connection with tracheal intubation. The study group received aerosolized lidocaine 100 mg 2 min before tracheal intubation, using a spray. The control group received no spray. The patients underwent a standardized general anaesthesia. The patients were interviewed when leaving the recovery room and the next day in the ward. Specific questions were asked regarding sore throat, cough and hoarseness. There were no significant differences between the two groups, which suggests that topical anaesthesia of the mucosa of the upper airway is ineffective as a means of ameliorating airway complaints in connection with tracheal intubation.
Received 5 July, accepted for publication 15 November 1991
Key words: Anesthesia: local; topical; intubation: intratracheal, endotracheal; lidocaine.
Tracheal intubation for general anaesthesia often leads to trauma of the airway mucosa, resulting in postoperative sore throat and cough (1). Methods to avoid these airway symptoms have been sought. Endotrachea1 lidocaine sprays are frequently used in clinical practice; however, there has been no evaluation of their effectiveness in reducing postoperative airway complaints. The aim of this study was to establish the effects of the application of aerosolized lidocaine to the mucosa of the upper airway on postoperative sore throat, hoarseness and cough. PATIENTS AND METHODS Two hundred patients, ASA group I and 11, aged 18 to 75 years, scheduled for elective gynaecologic, urologic, orthopaedic or abdominal surgery were studied. Patients requiring a gastric tube were excluded from the study. Informed consent was obtained from each patient, and the study was approved by the local Ethics Committee. The patients were randomly allocated in a double-blind manner to the study group (lidocaine spray (Xylocaine R, ASTRA)) or the control group (no spray)). Double blinding was achieved as follows: on inclusion, each patient was assigned a numbered envelope containing the result of randomisation. The envelope was opened by the anaesthetist and closed again; it was not opened again until the study was finished. Neither the patient nor the interviewer (one of the authors) was notified of the results of randomisation. On inclusion, the patients were informed about which questions were going to be asked and only to answer “yes” or “no” to cough? soreness? or hoarseness? Premedication consited of either diazepam 5-20 mg orally, lorazepam 1.25-2.5 mg orally or pethidine 0.5-1 mg/kg i.m. In the anaesthetic room the patients received atropine 0.5 mg and pethidine 0.5-1 mg/kg or fentanyl 1-2 p/kg. Induction was done with thiopen-
tone 3-5 mg/kg. The lungs were ventilated with 100% oxygen and relaxation was obtained with vecuronium 0.1 mg/kg. For the patients in the study group, after 2 min of mask ventilation, laryngoscopy was performed with a Macintosh blade and the lidocaine spray was applied: 3 sprays on the epiglottis, 3 on the vocal cords and 4 into the trachea. The total dose of lidocaine was 100 mg, as according to the manufacturer each spray contains 10 mg. The laryngoscope was then withdrawn and ventilation was continued for a further 2 min before intubation. For the patients in the control group, laryngoscopy and tracheal intubation were performed after 4 min of ventilation. Soft rubber tracheal tubes (Rusch R), size 9.5 mm inner diameter for males and 8.5 for females, were used, unless the anaesthetist judged that the trachea was too small and demanded a smaller tube. The cuff was inflated until no airleak could be heard. Plastic guedel airways were used, the size was decided by the anaesthetist and not recorded. Anaesthesia then continued with N,O/O, (2: 1) and either halothane or balanced anaesthesia with thiopentone and meperidine or fentanyl. T h e patients who had abdominal surgery and required continued relaxation were relaxed using bolus doses of vecuronium of 1-2 mg. Before extubation all patients received atropine 0.5-1.0 mg and neostigmine 1-2.5 mg. All patients were questioned about sore throat, cough and hoarseness before they left the recovery area, and the next day in the ward.
Statistical analysis The required number of patients was calculated in expectation of 40% with sore throat in the control group, and a reduction to 20% in the study group. Type 1 error was set to 5% and type 2 error to 10%. With this assumption, 100 patients were required in each group. The data are presented using median and 25-75 percentiles. Data on ordinal scale were tested using Mann-Whitney’s test and frequencies were tested using Fisher’s exact test. PC0.05 was considered statistically significant.
RESULTS Of 200 patients included, 7 were excluded because of procedural mistakes. There were no significant differ-
506
P. HERLEVSEN ET AL.
Table I General data on patients intubated after spraying of the upper airway with lidocaine and without spraying (numbers in parenthesis: 25 and 75 percentiles).
n Femalelmale Age Duration intubated (min) Hypotension* (n) Hypotension** (min) Difficult intubation (n)
Premedicalion: Diazepam (n) Lorazepam (n) Meperidine (n) Anaesthesia: Halothane (n) Balanced (meperidine) (n) Balanced (fentanyl) (n)
*
**
Lidocaine spray
No spray
96 30/66 46 (33-59) 95 (70-135) 22 30 (19-50) 5
97 21/76 47 (35-61) 100 (60-145) 16 22 ( I 1-79) 9
43 35 19
43 32 21
25 57 14
29 52 16
Systolic arterial pressure < 75% of preincubation value for more than 5 min. Duration of hypotension.
ences between the two groups with regard to age, sex, kind of premedication and anaesthetics, amount of opioid (premedicated opioids included), length of anaesthesia and intubation, difficulty with intubation (more than one attempt at passage of the tube), or incidence and duration of hypotension (Table 1). Thirty-two patients received a smaller tube in accordance with the anaesthetist’s judgement, 18 in the lidocaine group and 14 in the control group. Table 2 summarizes the incidence of sore throat, cough and hoarseness in our population. There were no significant differences between the two groups at any period of the study, although a trend toward higher incidence of sore throat was seen in the lidocaine group. Patients in both groups had a higher frequency Table 2 Side effects of tracheal intubation in patients intubated after spraying of the upper airway with lidocaine and without spraying (percentage in parenthesis).
n
Day of surgery Sore throat Hoarseness Cough One or more of sore throat, hoarseness or cough Next day Sore throat Cough One or more of sore throat or cough
Lidocaine spray
No spray
96
97
28 (29) 24 (25) 11 (11)
21 (22) 10 (10)
50 (52)
38 (39)
12 (13) 9 (9) 17 (18)
7 (7)
19 (20)
9(9) 13 (13)
of sore throat on the day of surgery as compared to the next day. DISCUSSION Many factors are involved in the aetiology of sore throat and laryngeal lesions following general anaesthesia. The intubation procedure itself (2), and the diameter of the tube are of importance. In a recent study it was shown that the incidence and severity of postoperative sore throat and hoarseness after endotracheal intubation was reduced by the use of smaller tubes (3). The amount of motor activity of laryngeal muscles while the tube is in place is of importance (4),in addition to the movement of the tube (5). A study demonstrated that the use of succinylcholine was related to sore throat, and that nondepolarizing pretreatment reduced the incidence somewhat (from 68 to 45%) (6). It has been shown that the frequency and severity of postoperative sore throat. after intubation were significantly greater after the use of low-pressure, highvolume cuffs (46-65%), than after the use of highpressure, low-volume cuffs (25-52%) (7, 8). Possible explanations may be that tracheal tube cuffs produce tracheal mucosal damage in direct relation to the cufftracheal wall contact area, which is known to be largest when low-pressure, high-volume cuffs are used (7), and furthermore it has been demonstrated, in a histological study, that low-pressure, high-volume cuffs produce grooves in the mucosa because of wrinkling of the cuff as it is inflated, unlike the situation after inflation of high-pressure, low-volume cuffs (9). A study of the shape of the tube led to the conclusion that an endotracheal tube which conforms to the anatomy of the airway, e.g. the Lindholm tube, causes less postoperative sore throat and a milder mucosal reaction in the posterior larynx than an ordinary shaped tube (1). That factors other than intubation trauma per se are involved is demonstrated by the fact that a mask technique is followed by sore throat in 15-18% of patients (8, 10). Possible explanations may be the drying of mucous membranes after ventilation with dry gasses and the use of antisialogogues (7). Different lubricants and anaesthetic agents have been applied to the tube in an attempt ot diminish airway irritation. The results of these studies have differed. It was reported that the incidence of sore throat after lubrication with 4% lignocaine jelly containing polyethylene and propylene glycols was 90%, as compared with 40% after lubrication with saline solution (10). However, it has been shown earlier, that patients
LIDOCAINE, TRACHEAL INTUBATION, SORE THROAT
507
might benefit from lubrication of tracheal tubes with 1% cinchocaine jelly (1 l ) , and Xylocain gel (12). The symptom sore throat may be considered as one of many postoperative airway complaints. In a study on the correlation between airway complaints and laryngeal pathology after intubation, Alexopoulus & Lindholm demonstrated that the main symptom of cuff lesions in the trachea was generally not sore throat, but an irritating cough (1). In keeping with this result, in the present study not only sore throat, but also cough and hoarseness were recorded. One of the probable reasons for the discrepancy between the frequency of discomfort in the airways in many previous investigations is that only sore throat was recorded. Laryngoscopy and tracheal intubation are potent stimuli that increase heart rate and blood pressure. Aerosolized lidocaine is widely used to blunt haemodynamic stimulation during the intubation procedure, although the efficacy of lidocaine treatment in this setting has been questioned (13, 14). The results of this study indicate that administration of lidocaine by aerosol before passage of the endotracheal tube provides no advantage in terms of postoperative sore throat, cough and hoarseness. I n fact, aerosolized lidocaine was associated with a higher incidence of sore throat (29.2%) than no lidocaine (19.6%), although this difference was not statistically significant. This finding suggests that lidocaine may be irritating or damaging to the mucosa of the trachea or upper airway. In conclusion, on the basis of this study, we do not recommend endotracheal lidocaine spray before intubation as a means of preventing the occurrence of postoperative airway complaints.
2. Haxholdt B F. Via falsa ved naso-tracheal intubation. Nord Med 1954: 52: 1589. 3. Stout D M, Bishop M J, DwerstegJ F, Cullen B F. Correlation of endotracheal tube size with sore throat and hoarseness following general anaesthesia. Anesfhesiology 1987: 67: 419-421. 4. Jackson C H. Contact ulcer gramuloma and other laryngeal complications of endotracheal anesthesia. Anesthesiology 1953: 14: 425. 5. Kleinsasser 0. Endotracheakatheter mit beweglicher Abdichtmanschette zur Vermeidung von Wandschadigungen der Luftrohre. Anaesfhesist 1969: 18: 382. 6. Capan L M, Bruce D L, Patel K P, TurndorfH. Succinylcholineinduced postoperative sore throat. Anesthesiology 1983: 59: 202-206. 7. Loeser E A, Orr D L, Bennett G M, Stanley T H. Endotracheal tube cuff design and postoperative sore throat. Anesthesiologr 1976: 45: 684-687. 8. Jensen P J, Hommelgaard P, Sendergaard P, Eriksen S. Sore throat after operation: influence of tracheal intubation, intracuff pressure and type of cuff. Br 3 Anaesth 1982: 54: 453-457. 9. Loeser E A, Hodges M, Gliedman J, Stanley T H, Johansen R K, Yonetani D. Tracheal pathology following short-term intubation with low- and high-pressure endotracheal tube cuffs. Anesth Analg 1978: 57: 577. 10. Loeser E A, Stanley T H, Jordan W, Machin R. Postoperative sore throat: influence of tracheal tube lubrication versus cuff design. Can Anaesth Sot 3 1980: 27: 156. 1 1 . Winkel E, Knudsen J. Effect on the incidence of postoperative sore throat of 2 per cent cinchocaine jelly for endotracheal intubation. Anesfh Analg 1971: 50: 92-94. 12. Lund L 0, Daos F G. Effects of postoperative sore throat of two analgetic agents and lubricants used with endotracheal tubes. Anesthesiology 1965: 26: 681-683. 13. Laurito C E, Baughman V L, Becker G L, Polek W V, Riegler F X, VadeBoncouer T R. Effects of aerosolized and/or intravenous lidocaine on hemodynamic responses to laryngoscopy and intubation in outpatients. Ancsfh Analg 1988: 6 7 389-392. 14. Denlinger J K, Ellison N, Ominsky A J. Effects of intratracheal lidocaine on circulatory responses to tracheal intubation. Anesthesiology 1974 41: 409-412.
REFERENCES
Address: Per Herleusen Purkervej 7 DK-9520 Skorping Denmark
I , Alexopoulos C, Lindholm C-E. Airway complaints and laryngeal pathology after intubation with an anatomically shaped endotracheal tube. Acta Anaesthesiol Scand 1983: 27: 33%344.
