Therapeutic
Intranasal Drug DeliveryIntranasal and intraoral topical anesthetics prior to minor ear, nose and throat procedures - abstracted references:
Ahmad, I., K. El-Boghdadly, et
al. (2020). "Difficult Airway Society guidelines for awake tracheal
intubation (ATI) in adults." Anaesthesia 75(4): 509-528.
Awake tracheal intubation has a high success rate and a favourable safety profile but is underused in cases of anticipated difficult airway management. These guidelines are a comprehensive document to support decision making, preparation and practical performance of awake tracheal intubation. We performed a systematic review of the literature seeking all of the available evidence for each element of awake tracheal intubation in order to make recommendations. In the absence of high-quality evidence, expert consensus and a Delphi study were used to formulate recommendations. We highlight key areas of awake tracheal intubation in which specific recommendations were made, which included: indications; procedural setup; checklists; oxygenation; airway topicalisation; sedation; verification of tracheal tube position; complications; management of unsuccessful awake tracheal intubation; post-tracheal intubation management; consent; and training. We recognise that there are a range of techniques and regimens that may be effective and one such example technique is included. Breaking down the key practical elements of awake tracheal intubation into sedation, topicalisation, oxygenation and performance might help practitioners to plan, perform and address complications. These guidelines aim to support clinical practice and help lower the threshold for performing awake tracheal intubation when indicated.
Babl, F. E., C. Goldfinch, et al. (2009). "Does nebulized lidocaine
reduce the pain and distress of nasogastric tube insertion in young
children? A randomized, double-blind, placebo-controlled trial."
Pediatrics 123(6):
1548-1555.
OBJECTIVES: Nasogastric tube insertion is a common procedure in
children that is very painful and distressing. Although nebulized
lidocaine has been shown to be effective in reducing the pain and
discomfort of nasogastric tube insertion in adults, there have been no
similar studies in children. We set out to investigate the role of
nebulized lidocaine in reducing pain and distress of nasogastric tube
insertion in young children. METHODS: We conducted a randomized,
double-blind, placebo-controlled trial of nebulized 2% lidocaine at 4
mg/kg versus saline placebo during nasogastric tube insertion at a
tertiary urban pediatric emergency department. Patients were eligible if
they were aged from 1 to 5 years with no comorbid disease and a clinical
indication for a nasogastric tube. Nebulization occurred for 5 minutes,
5 minutes before nasogastric tube insertion. Video recordings before,
during, and after the procedure were rated using the Face, Legs,
Activity, Cry, and Consolability (FLACC) pain and distress assessment
tool (primary outcome measure) and pain and distress visual analog scale
scores (secondary outcome measures). Difficulty of insertion and adverse
events were also assessed. RESULTS: Eighteen participants were nebulized
with 2% lidocaine and 18 participants with normal saline. Nebulization
was found to be highly distressing. FLACC scores during nasogastric tube
insertion were very high in both groups. There was a trend in the
post-nasogastric tube insertion period toward lower FLACC scores in the
lidocaine group. Visual analog scale scores for this postinsertion
period were significantly lower in the lidocaine arm for pain and
distress. There were no significant differences between groups in terms
of difficulty of insertion and the number of minor adverse events. The
study was terminated early because of the distress and treatment delay
associated with nebulization. CONCLUSIONS: Nasogastric tube insertion
results in very high FLACC scores irrespective of lidocaine use.
Nebulized lidocaine cannot be recommended as pain relief for nasogastric
tube insertion in children. The delay and distress of nebulization
likely outweigh a possible benefit in the postinsertion period.
Cullen, L., D. Taylor, et al. (2004). "Nebulized
lidocaine decreases the discomfort of nasogastric tube insertion: a
randomized, double-blind trial." Ann Emerg Med 44(2): 131-7.
STUDY OBJECTIVE: Nasogastric tube insertion is a common emergency department (ED) procedure that is associated with considerable patient discomfort. The safety and efficacy of nebulized lidocaine for upper airway anesthesia have previously been demonstrated. We determine whether nebulized lidocaine administered before nasogastric tube insertion significantly reduces patient discomfort. METHODS: A double-blind, placebo-controlled, randomized clinical trial of adult patients was conducted in the EDs of 2 university hospitals. Twenty-nine participants were administered nebulized lidocaine (4 mL 10%), and 21 participants received nebulized normal saline solution. Patient discomfort was measured using a 100-mm visual analog scale. The difficulty of nasogastric tube insertion was evaluated using a 5-point Likert scale. RESULTS: There was a clinical and statistical significant difference in patient discomfort associated with the passage of the nasogastric tube between nebulized lidocaine and placebo groups (mean visual analog scale score 37.7 versus 59.3 mm, respectively; difference between group means 21.6 mm; 95% confidence interval [CI] 5.3 to 38.0 mm). There was not a detectable difference in difficulty with the passage of the nasogastric tube between the 2 groups (median 2 versus 2; median difference 0; 95% CI -1 to 1). Epistaxis occurred more frequently in the lidocaine group (17% versus 0%; difference 17%; 95% CI 3.5% to 31%). CONCLUSION: Nebulized lidocaine decreases the discomfort of nasogastric tube insertion and should be considered before passing a nasogastric tube. An increased frequency of epistaxis, however, may be associated with its use.
Dhir, V., V. S. Swaroop, et al. (1997). "Topical
pharyngeal anesthesia without intravenous sedation during upper
gastrointestinal endoscopy." Indian J Gastroenterol 16(1): 10-1.
BACKGROUND: There have been conflicting reports about the usefulness of topical pharyngeal anesthesia as a pre-endoscopic medication. AIMS: To assess the effect of topical pharyngeal anesthesia without intravenous sedatives on easing upper gastrointestinal endoscopy. METHODS: 153 consecutive consenting patients were randomized to receive either placebo (normal saline) spray (78 patients) or 80 mg of 4% lidocaine spray (75 patients). Difficulty of intubation was judged both by the patient and the physician on a linear analogue scale. RESULTS: There was no significant difference in the scores in the two groups (p > 0.05). The patient and physician assessments correlated well. CONCLUSIONS: Topical lignocaine spray does not facilitate upper gastrointestinal endoscopy in the absence of intravenous sedation.
Ducharme, J. and K. Matheson (2003). "What is
the best topical anesthetic for nasogastric insertion? A comparison of
lidocaine gel, lidocaine spray, and atomized cocaine." J Emerg Nurs
29(5): 427-30.
INTRODUCTION: Nasogastric intubation has been shown to be a painful procedure for patients. Previous studies have demonstrated the benefit of topical nasal anesthesia in decreasing the pain of this procedure. This study attempts to identify which of 3 topical anesthetic modalities would be preferred by patients. METHODS: This study had a double-blind, double-dummy randomized triple crossover design with 30 healthy volunteers as participants. Each participant had 3 nasogastric tubes inserted and acted as his or her own control for the 3 study medications: 1.5 mL 4% atomized lidocaine, 1.5 mL 4% atomized cocaine, and 5 mL 2% lidocaine gel. Participants scored pain of tube passage through the nostril as well as global discomfort. They were also asked to identify which agent they preferred. RESULTS: In our 30 subjects, although no statistically significant difference in nasal pain scores was found, "global discomfort" was less with the lidocaine gel (P =.017). Participants preferred the lidocaine gel over atomized cocaine (P <.00), but not to a statistically significant degree. DISCUSSION: Two percent lidocaine gel appeared to provide the best option for a topical anesthetic during nasogastric tube insertion.
Frosh, A. C., S. Jayaraj, et al. (1998). "Is
local anaesthesia actually beneficial in flexible fibreoptic
nasendoscopy?" Clin Otolaryngol Allied Sci 23(3): 259-62.
Although the application of a topical local anaesthetic before fibreoptic nasendoscopy is routine practice in many otolaryngological outpatients, the actual benefit to the patient of this procedure remains in doubt. Eighty-two patients were recruited in this double-blind randomized control trial which compared the patients' experiences of fibreoptic nasendoscopy with nasal preparations of Xylocaine (lidocaine), normal saline, and no spray to the nose and throat. A visual analogue scoring system was used to determine scores for the overall unpleasantness of procedure, receiving a spray, and taste of the spray, and pain. This study has shown significantly worse overall experience (P = 0.001) and pain (P = 0.048) scores for Xylocaine spray versus no spray. It is concluded that the routine use of topical local anaesthetics within the nose before routine fibreoptic nasendoscopy is not only of no value, but actually makes the experience worse for the patient.
Gordon, M. J., G. R. Mayes, et al. (1976).
"Topical lidocaine in preendoscopic medication." Gastroenterology
71(4): 564-9.
A double blind study of 111 consecutive elective upper gastrointestinal endoscopies performed with a flexible fiberoptic esophagogastroduodenoscope was made to determine the efficacy of topical pharyngeal anesthesia with lidocaine as an adjunct to intramuscular meperidine, intramuscular atropine, and intravenous diazepam. Patients who received lidocaine rated the over-all endoscopy and passage of the endoscope significantly easier than did those receiving placebo. The endoscopist found that patients who received lidocaine tolerated endoscopy significantly better, although gagging was not affected.
Graham, D. R., J. G. Hay, et al. (1992).
"Comparison of three different methods used to achieve local anesthesia
for fiberoptic bronchoscopy." Chest 102(3): 704-7.
A patient's tolerance of fiberoptic bronchoscopy depends on the effectiveness of local anesthesia. This study compares the three different methods of local anesthesia in common use After sedation, patients (n = 53) received either 4 ml of 2.5 percent cocaine by intratracheal injection (TI) (n = 18), by bronchoscopic injection (BI) (n = 19), or had 4 ml of 4 percent lidocaine delivered by nebulizer 20 min before the procedure (NEB) (n = 16). Patients and bronchoscopists scored the procedure using visual analog (VAS) and severity scales. Objective measurements of cough counts and episodes of stridor were recorded by phonopneumography. Patients' VAS scores showed a clear preference for the transtracheal method compared with either bronchoscopically injected cocaine (p less than 0.001) or nebulized lidocaine (p less than 0.001). Patients also reported that the TI method produced less cough during intubation of the larynx and inspection of the airways (BI and NEB, p less than 0.01). The TI method was also preferred by the bronchoscopists (BI and NEB, p less than 0.001); they reported less cough and easier tracheal intubation. The mean cough count was significantly lower for the TI group, 49 (43) compared with 95 (52) for BI (p less than 0.01), and 81 (43) for the NEB group (p less than 0.05). Patients' and bronchoscopists' VAS showed significant correlation with cough (r = 0.63-69, p less than 0.01). Stridor occurred in only two patients after TI, compared with 15 in the other two groups. Extra local anesthesia was required by 16 patients after BI, by all the NEB group, but by only one patient after TI. Subjective and objective measurement shows that 4 ml of 2.5 percent cocaine injected into the trachea produced excellent local anesthesia for fiberoptic bronchoscopy, there were no extra complications, and it was the method preferred by both patients and bronchoscopists.
Groeben, H., T. Grosswendt, et al. (2000).
"Lidocaine inhalation for local anaesthesia and attenuation of bronchial
hyper-reactivity with least airway irritation. Effect of three different
dose regimens." Eur J Anaesthesiol 17(11): 672-9.
The inhalation of lidocaine attenuates bronchial hyper-reactivity but also causes airway irritation. However, how lidocaine dose and plasma concentration influence relationships are unknown. Accordingly, we evaluated the effects of three concentrations of lidocaine (1, 4, and 10%, total dose of 0.5, 2.0, and 5.0 mg kg-1, respectively) vs. placebo in 15 mild asthmatic patients, selected by their response to a histamine challenge (decrease in FEV1 > 20% to less than 18 mg mL-1 of histamine [PC20]). Baseline lung function, histamine-induced bronchoconstriction, topical anaesthesia, and lidocaine plasma concentrations were obtained. FEV1 following lidocaine inhalation showed the greatest decrease for the highest dose (from 3.79 +/- 0.15-3.60 +/- 0.15; P = 0.0012). Lidocaine inhalation increased baseline PC20 (6.1 +/- 1.3 mg mL-1) significantly (to 11.8 +/- 3.1, 16.1 +/- 3.3, and 18.3 +/- 4.5 mg mL-1, respectively) with no difference between the two highest doses. The duration of local anaesthesia was not significantly different between lidocaine concentrations of 4% and 10%. Thus, lidocaine inhalation, with increasing concentrations of the aerosolized solution, increases initial bronchoconstriction while significant attenuation of bronchial hyper-reactivity is not further enhanced with increasing concentrations from 4 to 10%. Plasma concentrations of lidocaine were always far below the toxic threshold. In conclusion, when local anaesthesia of the airways is required a lidocaine dose of 2.0 mg kg-1 as a 4% solution can be recommended for local anaesthesia and attenuation of bronchial hyper-reactivity with the least airway irritation.
Hedenbro, J. L., M. Ekelund, et al. (1992). "A
randomized, double-blind, placebo-controlled study to evaluate topical
anaesthesia of the pharynx in upper gastrointestinal endoscopy."
Endoscopy 24(6): 585-7.
Reduction of discomfort during diagnostic upper endoscopy may not be desired by patients if the medication has long-lasting and severe after-effects. The present study was designed to examine whether topical anaesthesia of the pharynx without concomitant sedation is of overall benefit to patients undergoing diagnostic upper endoscopy. Two hundred out-patients were randomized to receive in the form of a pharyngeal spray either 80-120 mg lidocaine or placebo. Patients assessed discomfort on a 100 mm visual analogue scale the day after examination. Patients undergoing endoscopy who received lidocaine spray experienced significantly less discomfort from the intubation (p = 0.0001), and discomfort induced by the rest of the examination was also reduced (p = 0.003). The outcome of the endoscopists' assessment was also in favour of lidocaine spray for intubation (p = 0.157) and ease of examination (p = 0.0014). The assessment of throat discomfort suffered by patients after endoscopy did not differ between the groups. A majority of patients, the same proportion in each group, stated they would prefer their next endoscopy to be performed with topical anaesthesia.
Jameson, J. S., S. A. Kapadia, et al. (1992).
"Is oropharyngeal anaesthesia with topical lignocaine useful in upper
gastrointestinal endoscopy?" Aliment Pharmacol Ther 6(6): 739-44.
The aim of this study was to determine whether patients' tolerance of upper gastrointestinal endoscopy is related to the dose of lignocaine spray used for oropharyngeal anaesthesia and to measure plasma concentrations at these doses. Sixty consecutive patients undergoing routine upper gastrointestinal endoscopy with sedation were randomized to receive lignocaine spray 50 mg (Group A), 100 mg (Group B) or 200 mg (Group C). Patient, endoscopist and endoscopy nurse were unaware of the variation in dose used. Each patient's tolerance of the intubation and of the remainder of the gastroscopy was assessed independently by the patient, endoscopy nurse, and endoscopist using a visual analogue scale. Plasma lignocaine concentration was measured at 20, 40, 60 and 80 min after administration of the spray. Fifty (83%) patients were unable to recall either the intubation, or the procedure. On the endoscopy nurse's assessment, the patients in Group B tolerated the intubation better than those in Group A, and Groups B and C tolerated the remainder of the gastroscopy better than those in Group A. On the endoscopist's assessment, Groups B and C tolerated the remainder of the gastroscopy better than Group A. There were fewer gags per min in Groups B and C compared to Group A. Mean plasma lignocaine concentrations showed a dose-dependent absorption of the spray, but none exceeded the potentially toxic level of 5 mg/L.
Korttila, K. (1984). "Local anesthetic
techniques for bronchoscopies." Acta Anaesthesiol Belg 35 Suppl:
389-97.
Local anesthetic techniques are often preferable to general anesthesia for bronchoscopies since these examinations are mostly undertaken as outpatient procedures. To be successful bronchoscopy under local anesthesia must satisfy three criteria: the technique used must produce adequate anesthesia: the procedure must be safe: and the technique should be easy for the patient as well as for the physician. Local anesthesia of the respiratory tract for these procedures can be achieved by laryngotracheal spraying or ultrasonic nebulizer administration of lidocaine. For fiberoscopic procedures lidocaine can also be administered through the fiberoscope. When the local anesthetic techniques are supplemented with light sedation, the procedure is easier and more acceptable to the patients. Using small doses of diazepam, flunitrazepam, or midazolam i.v. one can produce amnesia for the procedure and still discharge the patients 2 h after the procedure with a responsible adult. In many cases local anesthesia supplemented by intravenous sedation is a proper alternative and should be preferred to general anesthesia in ambulatory practice for diagnostic bronchoscopies.
Mainland, P. A., A. S. Kong, et al. (2001).
"Absorption of lidocaine during aspiration anesthesia of the airway."
J Clin Anesth 13(6): 440-6.
STUDY OBJECTIVE: To determine the optimal solution to use when anesthetizing the airway by aspiration of lidocaine. DESIGN: Randomized, double-blind clinical study. SETTING: University hospital. PATIENTS: 96 adult ASA physical status 1,II, and III patients, scheduled for diagnostic flexible bronchoscopy. INTERVENTIONS: Patients were randomized to receive one of 5 solutions of lidocaine: Group A (n = 16): 1% lidocaine, 0.2 mL. kg(-1); Group B (n = 16): 1.5% 0.2 mL. kg(-1); Group C (n = 32): 2% 0.2 mL. kg(-1); Group D (n = 16): 1% 0.3 mL. kg(-1), and Group E (n = 16): 2% 0.3 mL. kg(-1). Fiberoptic bronchoscopy was performed after the airway was anesthetized with this aspiration technique, using the assigned lidocaine solution. The scope was manipulated in the trachea to test for anesthesia. MEASUREMENTS AND MAIN RESULTS: Successful airway anesthesia was determined by tolerance to bronchoscopy without sustained coughing, and also by the number of lidocaine supplements, if any, that were given via the bronchoscope. Arterial plasma concentrations of lidocaine were measured in 33 patients from Groups C, D, and E. All solutions provided equally effective anesthesia of the airway. All patients tolerated endoscopy through the vocal cords, and 94 patients required no supplementary anesthesia, or only one dose of lidocaine, during bronchoscopy to the carina. The highest peak plasma concentrations of lidocaine were 5.02 and 6.28 microg. mL. No patient had signs of toxicity. CONCLUSIONS: This technique produced anesthesia of the airway to the carina, safely, suitable for awake intubation, in 94 of 95 patients. The use of 1% lidocaine, 0.2 to 0.3 mL. kg(-1), so that the volume is 10 to 20 mL, is recommended.
Middleton, R. M., A. Shah, et al. (1991).
"Topical nasal anesthesia for flexible bronchoscopy. A comparison of
four methods in normal subjects and in patients undergoing transnasal
bronchoscopy." Chest 99(5): 1093-6.
We evaluated nasal anesthesia regimens by comparing, in seven normal men, four drug regimens: 1) 1 percent phenylephrine; 2) 4 percent lidocaine; 3) 1 percent phenylephrine + 4 percent lidocaine; and 4) 5 percent cocaine. After spraying each drug into the anterior nares, vasoconstriction, decongestion, and nasal anesthesia (measured as transnasal depth of nasogastric (NG) tube insertion before discomfort) were assessed. There were no significant differences in NG tube insertion depth between the regimens (p = 0.54). Insertion depth was significantly increased after 10 ml of 2 percent viscous lidocaine were sniffed (p less than 0.004), but again, differences between regimens were not significant (p = 0.051). One hundred bronchoscoped patients received one of the following sprayed into the nose: 1) placebo (P); 2) 1 percent phenylephrine + P; 3) 1 percent phenylephrine + 4 percent lidocaine; or 4) 5 percent cocaine + P. Each patient then sniffed viscous lidocaine. There were no significant differences between regimens for any of the following: 1) nasal resistance to bronchoscope insertion, 2) patient's nasal discomfort, or 3) bronchoscopist's perception of patient discomfort. We conclude that sprayed anesthetics contribute little to nasal anesthesia and any regimen appears acceptable when viscous lidocaine is used.
Mulcahy, H. E., R. R. Greaves, et al. (1996). "A
double-blind randomized trial of low-dose versus high-dose topical
anaesthesia in unsedated upper gastrointestinal endoscopy." Aliment
Pharmacol Ther 10(6): 975-9.
BACKGROUND: Upper gastrointestinal endoscopy is frequently performed on unsedated subjects. Pharyngeal anaesthesia is thought to improve patient tolerance to the procedure but the optimum dose of anaesthesia is not known. The aim of this study was to assess the benefits of low-dose vs. high-dose topical anaesthesia in unsedated gastroscopy. METHODS: One hundred and fourteen subjects attending for diagnostic gastroscopy were studied. Patients were randomized to receive either 30 mg or 100 mg of topical pharyngeal lidocaine spray prior to endoscopy in a double-blind fashion. Subjects completed a questionnaire before and after endoscopy. RESULTS: A similar proportion of patients in each group required intravenous sedation because of discomfort or anxiety during the procedure (P = 0.48). The high-dose group experienced less discomfort during endoscope insertion (P = 0.002) and throughout the examination (P = 0.01). Overall satisfaction was almost identical in the two groups (P = 0.85) and a similar percentage of the high-dose and low-dose groups stated that they would request sedation prior to future endoscopy (37 vs. 44%; P = 0.48). Further analysis showed that apprehensive patients and younger patients reported relatively high levels of discomfort, and that female subjects were more likely to express a preference for sedation at any future gastroscopy. CONCLUSION: High-dose pharyngeal anaesthesia reduces patient discomfort during unsedated upper gastrointestinal endoscopy. However, patient tolerance is also influenced by clinical features, which might be useful in deciding which patients are suitable for this procedure.
Ristikankare, M., J. Hartikainen, et al. (2004).
"Is routine sedation or topical pharyngeal anesthesia beneficial during
upper endoscopy?" Gastrointest Endosc 60(5): 686-94.
BACKGROUND: Upper endoscopy is an invasive procedure. However, the benefits of routinely administered sedative medication or topical pharyngeal anesthesic are controversial. The aim of this study was to clarify their effects on patient tolerance and difficulty of upper endoscopy. METHODS: A total of 252 patients scheduled for diagnostic upper endoscopy were randomly assigned to 4 groups: (1) sedation with midazolam and placebo pharyngeal spray (midazolam group), (2) placebo sedation and lidocaine pharyngeal spray (lidocaine group), (3) placebo sedation and placebo pharyngeal spray (placebo group), and (4) no intravenous cannula/pharyngeal spray (control group). The endoscopist and the patient assessed the procedure immediately after the examination. Another questionnaire was sent to the patients 2 weeks later. RESULTS: Patients in the midazolam group rated the examination easier and less uncomfortable compared with those in the other groups. The differences were especially evident in the questionnaires completed 2 weeks after the examination ( p < 0.001). Lidocaine did not significantly improve patient tolerance. However, endoscopists found the procedure easier in patients in the lidocaine group compared with the midazolam ( p < 0.01) and control groups ( p < 0.01) but not the placebo group. CONCLUSIONS: Routine administration of midazolam for sedation increased patient tolerance for upper endoscopy. However, endoscopists found intubation to be more difficult in sedated vs. non-sedated patients. Topical pharyngeal anesthesia did not enhance patient tolerance, but it did make upper endoscopy technically easier compared with endoscopy in patients sedated with midazolam without topical pharyngeal anesthesia, and in patients who had no sedation or pharyngeal anesthesia, but not in patients who received placebo sedation and placebo pharyngeal anesthesia.
Sitzman, B. T., G. F. Rich, et al. (1997).
"Local anesthetic administration for awake direct laryngoscopy. Are
glossopharyngeal nerve blocks superior?" Anesthesiology 86(1):
34-40.
BACKGROUND: Glossopharyngeal nerve (GPN) blocks may provide reliable analgesia for awake direct laryngoscopy, although this has not been evaluated prospectively. This study was designed to determine if GPN blocks provide a superior route of local anesthetic administration for awake direct laryngoscopy as measured by hemodynamic, gag, and subjective pain responses. METHODS: A prospective, randomized, single-blinded, crossover design was used. All participants (n = 11) were anesthesiologists. Three routes of local anesthetic administration were evaluated: 2 min of 2% viscous lidocaine swish and gargle (S&G); S&G combined with 10% lidocaine spray (S&G/spray); and S&G combined with 1% lidocaine bilateral GPN blocks (S&G/block; anterior tonsillar pillar method). Five minutes after the local anesthetic was administered, laryngoscopy was performed and sustained for 20 s. Noninvasive hemodynamic measurements and serum lidocaine concentrations were determined. Visual analogue scale scores and a poststudy questionnaire were used to assess participants' ability to tolerate local anesthetic administration and laryngoscopy and their choice for use in clinical practice. RESULTS: No significant hemodynamic changes were observed, although there was a modest increase (< 15%) in heart rate in the S&G/block group in the first minute after laryngoscopy. Serum lidocaine concentrations were higher (P < 0.05) in the S&G/block group at 5 and 10 min (0.5 +/- 0.1 and 1.0 +/- 0.2 microgram/ml) compared with the S&G group. Participants' visual analogue scale scores, which assessed their ability to tolerate laryngoscopy, showed that S&G (5.4 +/- 0.9) resulted in more discomfort (P < 0.05) than either S&G/spray (3.5 +/- 0.9) or S&G/block (3.3 +/- 0.7). The laryngoscopist's visual analogue scale scores, which assessed the ease of visualization, revealed a trend (P < 0.08) toward less coughing and gagging with S&G/spray (1.8 +/- 0.9) compared with S&G (4.0 +/- 1.3) and S&G/block (3.7 +/- 1.1). Oropharyngeal discomfort lasting 24 h or more was reported by 91% of participants after S&G/block, whereas no participant reported oropharyngeal discomfort after S&G or S&G/spray. Significantly more participants (73%) indicated their preference for using S&G/spray in future clinical practice compared with S&G (P < 0.01) and S&G/block (P < 0.05). CONCLUSIONS: Glossopharyngeal nerve blocks do not provide a superior route of local anesthetic administration for awake direct laryngoscopy. Two minutes of 2% viscous lidocaine S&G followed by 10% lidocaine spray was the anesthetic route preferred by participants and laryngoscopists.
Stoelting, R. K. (1977). "Circulatory response
to laryngoscopy and tracheal intubation with or without prior
oropharyngeal viscous lidocaine." Anesth Analg 56(5): 618-21.
Oropharyngeal topical anesthesia with viscous lidocaine (25 ml of 2% as a "mouthwash and gargle" 10 min before laryngoscopy) attenuated the pressor but not heart rate (HR) response during laryngoscopy and tracheal intubation. Compared with control patients, mean arterial pressure (MAP) increased less in response to tracheal intubation (23 +/- 5 torr versus 39 +/- 4 torr, p less than 0.05) and returned toward awake levels sooner in patients receiving viscous lidocaine. MAP increased more than 40 torr in response to intubation in 6/20 patients treated with viscous lidocaine, while 12/20 control patients manifested this degree of blood pressure elevation. HR increased about 20 bpm (p less than 0.05) with or without viscous lidocaine. Arterial lidocaine concentrations were less than 0.5 microgram/ml after oropharyngeal anesthesia. Prior topical anesthesia of the oropharynx with viscous lidocaine should be considered when pressor responses during tracheal intubation would be particularly likely or hazardous.
Stolz, D., P. N. Chhajed, et al. (2005).
"Nebulized lidocaine for flexible bronchoscopy: a randomized,
double-blind, placebo-controlled trial." Chest 128(3): 1756-60.
OBJECTIVE: Topical anesthesia for flexible bronchoscopy can be administered via transcricoid injection, nebulizer, or directly through the bronchoscope in a "spray as you go" fashion. We performed a prospective, randomized, double-blind, placebo-controlled trial to evaluate whether nebulized lidocaine provides additional benefit and reduces the total anesthetic dose required during bronchoscopy. SETTING: Tertiary care university hospital. METHODS: One hundred fifty patients (93 men; age, 20 to 89 years) undergoing diagnostic flexible bronchoscopy were randomized to receive either 4 mL of 4% lidocaine (160 mg) or 4 mL of saline solution as placebo via nebulization. Combined sedation was achieved using 5 mg of IV hydrocodone and midazolam boluses. Supplemental lidocaine doses and total midazolam required as judged by the bronchoscopist were recorded for each patient. After the procedure, both bronchoscopists and patients charted their perception of cough on a 10-cm visual analog scale (VAS). Similarly, patients recorded their discomfort related to the procedure on a 10-cm VAS. RESULTS: The most common procedures were BAL in 77 cases (51%), transbronchial biopsy in 40 cases (27%), and transbronchial needle aspiration in 34 cases (23%). Outcome parameters, including hemodynamic findings, duration of the procedure, cough scores for physicians and patients, discomfort score for patients, midazolam doses, and supplemental lidocaine doses, were similar in both groups. Mean total lidocaine dose required in the lidocaine group was 318 +/- 41 mg and was significantly higher than the total dose required in the placebo group (157 +/- 44 mg [+/- SD]) [p < 0.001]. CONCLUSION: Additional nebulized lidocaine cannot be recommended for flexible bronchoscopy performed under combined sedation.
Sutherland, A. D. and J. P. Sale (1986). "Fibreoptic
awake intubation--a method of topical anaesthesia and orotracheal
intubation." Can Anaesth Soc J 33(4): 502-4.
Three cases of trismus caused by oropharyngeal sepsis are described where fibreoptic-assisted awake intubation using an oral airway intubator and nebulised lidocaine was safely and successfully achieved.
Venus, B., V. Polassani, et al. (1984). "Effects
of aerosolized lidocaine on circulatory responses to laryngoscopy and
tracheal intubation." Crit Care Med 12(4): 391-4.
Topical anesthesia of oropharynx with lidocaine aerosol (6 ml of 4% for 5 min) prevented hypertension and tachycardia during laryngoscopy and tracheal intubation. In the control group (saline aerosol), systolic and mean BP as well as heart rate (HR) significantly increased during laryngoscopy and intubation. These changes were still present after 5 min. No patient in the aerosolized lidocaine group developed any premature ventricular contraction (PVC), but 4 of 10 patients in the control group had 2 to 3 PVCs during laryngoscopy and intubation. The pressor response and tachycardia observed during laryngoscopy and tracheal intubation were, thus, successfully prevented by lidocaine aerosolization. This simple technique for oropharyngeal anesthesia before laryngoscopy intubation may be considered, particularly in patients with intracranial pathology and/or decreased myocardial reserve.
Williams, K. A., G. L. Barker, et al. (2005).
"Combined nebulization and spray-as-you-go topical local anaesthesia of
the airway." Br J Anaesth 95(4): 549-53.
BACKGROUND: Twenty-five anaesthetists underwent awake fibreoptic intubation using a combination of nebulization and topical local anaesthesia. Plasma lidocaine concentrations were measured and the quality of the local anaesthesia was assessed. METHODS: After i.v. glycopyrrolate 3 microg kg(-1) and intranasal xylometolazone 0.1%, lidocaine 4% 200 mg was administered by nebulizer. Supplementary lidocaine to a maximum total of 9 mg kg(-1) was applied directly and via a fibreoptic endoscope. Nasotracheal intubation was performed once the vocal cords became unreactive. Heart rate, non-invasive blood pressure and oxygen saturation were recorded at 5-min intervals. Blood sampling commenced with a baseline sample and continued at 10 min intervals until 60 min after final administration of local anaesthetic. Subjects graded levels of anxiety, pain and coughing using written and visual analogue scales. RESULTS: Conditions for fibreoptic endoscopy and intubation were good. Seventeen received the maximum lidocaine dose of 9 mg kg(-1). The average dose used was 8.8 mg kg(-1). All plasma lidocaine concentrations assayed were below 5 mg litre(-1). Four volunteers reported feeling lightheaded after the procedure, despite normal blood pressure. Of these, two had the highest plasma lidocaine concentrations recorded: 3.5 and 4.5 mg litre(-1). Twenty-two of the 25 subjects found endoscopy and intubation acceptable, three found it enjoyable and no subject rated it as distressing. CONCLUSIONS: This method of airway anaesthesia was acceptable to this small group of unsedated subjects. It produced good conditions for fibreoptic intubation. A maximum calculated lidocaine dose of 9 mg kg(-1) did not produce toxic plasma concentrations of lidocaine.
Wolfe, T. R., D. E. Fosnocht, et al. (2000).
"Atomized lidocaine as topical anesthesia for nasogastric tube
placement: A randomized, double-blind, placebo-controlled trial." Ann
Emerg Med 35(5): 421-5.