Ann Otol 85: 1976
LOCAL ANESTHESIA FOR SUSPENSION MICROLARYNGOSCOPY THOMAS
C.
CALCATERRA,
JAMES HOUSE,
Los
M.D.
M.D.
ANGELES, CALIFORNIA
SUMMARY - Despite the strong trend toward use of general anesthesia for laryngoscopy, local anesthesia retains inherent advantages from the standpoint of patient safety and maintenance of physiologic function of the larynx during endoscopy. Topical anesthesia produces incomplete sensory blockade and is unsatisfactory for suspension laryngoscopy. A method of infiltration anesthesia is described whereby profound anesthesia of the base of the tongue, valleculae, and larynx can be achieved to allow suspension laryngoscopy.
jection of an inert polymer paste is far more accurate when the vocal cords can be monitored during voluntary phonation.
During the development of peroral endoscopy, topical anesthesia was used almost exclusively; and as recently as 1962, 70% of those institutions replying to a questionnaire reported that local anesthesia was being used predominantly.! The past 20 years, however. have witnessed an increasing trend toward general anesthesia," based on its convenience of use and greater sophistication. Suspension laryngoscopy and the operating microscope have placed increasing reliance on general anesthe• 3 sia.
Among the disadvantages of local anesthetic when administered by the classical topical transmucosal route, the foremost is incomplete anesthesia, resulting in considerable distress to the patient and, thus, lack of cooperation during the procedure. The topical anesthetic method is time-consuming and requires a period of 15 to 20 minutes to achieve maximum effect,4 yet the duration of anesthesia may be insufficient to complete the entire endoscopic examination. The inconsistency of the effectiveness of topical anesthesia is largely the result of different absorption capacities of the alimentary and respiratory mucous membranes that may vary unpredictably in type from thin ciliated columnar to thick squamous epithelium. In addition. oropharyngeal secretions pooling in the hypopharynx interfere with the absorption of a topical anesthetic.
ADVANTAGES AND DISADVANTAGES OF LOCAL ANESTHESIA
The advantages of local anesthesia for endoscopy are numerous, the foremost clearly being increased safety, particularly with severely ill patients or those with pulmonary disease. Administration of local anesthetic obviates the prolonged postoperative denression that inhibits the normal cough reflex and predisposes the patient to aspiration and pneumonia. Furthermore, the patient can cough voluntarily during endoscopy to facilitate procurement of aspirates for bacteriologic and cytologic study. Local anesthesia does not result in the motor paralysis that makes impossible neuromuscular evaluation for the larynx and hyoooharynx, Thus, the treatment of paralytic dysphonia by in-
The dosage of topical anesthetic required to obtain satisfactory anesthesia often narrowly reaches the limits of safety. Topical anesthetic drugs applied to the respiratory epithelium characteristically are absorbed into the systemic
From the Department of Surgery, Division of Head and Neck Surgery, UCLA School of Medicine, Los Angeles, California.
71
Downloaded from aor.sagepub.com at CARLETON UNIV on June 27, 2015
CALCATERRA-HOUSE
72
circulation with the rapidity of an intravenous injection, thereby increasing the risk of serious drug toxicity. The addition of a vasoconstricting agent, such as epinephrine, does not significantly retard absorption of most anesthetic drugs.
Tonsil\ needle \
\
, , I':
I
METHODS AND MATERIAL
The ideal anesthetic would provide maximum anesthesia to the stimulated region with minimal absorption through other surfaces, avoiding the hazardous peaks of drug concentration in the systemic circulation. Based on the limitations of both general anesthesia and topical anesthesia for peroral endoscopy, regional nerve blocks were first utilized for this procedure at the UCLA Hospital in 1965. Initially, just the superior laryngeal nerves as they passed through the thyrohyoid membrane were blocked by bilateral percutaneous administration to the neck of 2 to 4 ml of lidocaine.f Intraoral blockade of the glossopharyngeal nerve was subsequently employed to supplement the anesthesia of the pharynx. 6 During the past seven years, more than 500 endoscopic examinations have been accomplished successfully with techniques that blockade the superior laryngeal nerve percutaneously and the glossopharyngeal nerve perorally." Occasionally, precise location of the superior laryngeal nerves was difficult, particularly in patients with short thick necks whose cartilaginous laryngeal landmarks could not easily be palpated. Other patients were encountered in whom adeauate anesthesia of the base of the tongue, valleculae, and epiglottis could not be obtained, despite apparent blockade of the superior laryngeal and glossopharyngeal nerves. Suspension microlaryngoscopy then proved to be impossible without general anesthesia because of discomfort at the base of the tongue and epiglottis. Careful questioning of our patients after laryngoscopy revealed that the distal tip of the laryngoscope was the source of most discomfort. A method was devised to provide maximum anesthesia of the base of the tongue and the supraglottic portion of the larynx sufficient to perform suspension laryngoscopy. TECHNIQUE
Premedication one hour prior to endoscopy usually consists of 100 mg of sodium pentobarbital (Nembutal) ,®ft 100 mg of meperidine hydrochloride (Demerol) ,®"ft and hydroxyzine hy-
Fig. 1. With the base of tongue elevated forward, small increments of lidocaine are infiltrated at the sites indicated.
drochloride (Atarax) .®"U At operation 5 to 10 mg of diazepam (Valium)®OOOO may be administered to supplement the premedication until slurred speech occurs. The neck is prepared for nerve block, and each superior laryngeal nerve is anesthetized at the thyrohyoid membrane with about 2 ml of 1% lidocaine hydrochloride. The glossopharyngeal nerve is blocked bilaterally with 1% lidocaine hydrochloride just behind the posterior tonsillar pillar at its midpoint superior inferiorly. If bronchoscopy is planned, 2 to 3 ml of 1% lidocaine hydrochloride are injected through the cricothyroid membrane into the tracheal lumen to provide topical anesthesia of the tracheobronchial tree. The endoscopist then moves to the head of the table and extends the patient's neck. Under headlight illumination, the base of the tongue is gently elevated with a broad-bladed metal tongue depressor held in the same fashion as a laryngoscope. This maneuver provides excellent exposure of the valleculae, hypopharynx, epiglottis, and pyriform fossae. With a long-angled tonsil needle with 1 em of exposed tip, small increments (less than 1 ml) of
" Abbott Laboratories, North Chicago, Ill . ee Winthrop Laboratories, New York, NY. .. 00 Roerig, New York, NY. , ........ Roche Laboratories, Nutley, NJ.
Downloaded from aor.sagepub.com at CARLETON UNIV on June 27, 2015
ANESTHESIA FOR MICROLARYNGOSCOPY
1% lidocaine are infiltrated across the base of the tongue, lingual surface of epiglottis, and the anterior aspect of each pyriform fossae (Fig. 1). Aspiration of the needle is always first attempted prior to injection to avoid intravascular administration of the anesthetic. Generally, less than 10 ml of 1% lidocaine are required to produce profound anesthesia of the base of the tongue, larynx, and pharynx. Patients may undergo complete endoscopic examination of these areas without discomfort, and most will tolerate suspension laryngoscopy as it is performed with the laryngoscope stabilized on a platform over the chest. Because of the complete anesthesia produced, the patient is not allowed to swallow for four hours. COMMENT
Jafek et ali detailed the neuroanatomy of the base of the tongue and hypopharynx and concluded that present understanding of the sensory func-
73
tion in this area is incomplete. Certainly, an extensive sensory pharyngeal plexus exists that receives efferents from both the glossopharyngeal and vagus nerves. Because it is probably impossible to anesthetize the glossopharyngeal area simply by blocking the posterior pharyngeal segment of the glossopharyngeal nerves, this method of local infiltration of the area most stimulated during laryngoscopy was devised. The technique was initially designed for Teflon® displacement of the unilateral paralyzed vocal cord when it is advantageous to have both hands free, to use magnification with suspension laryngoscopy, and, most importantly, to permit voluntary movement of the normal vocal cord. Our success with this approach led to the broader application for local endoscopy. We have found this method of anesthesia to be uniformly predictable, rapid, and readily tolerable by the patient.
Reprints: Thomas C. Calcaterra, M.D., Division of Head and Neck Surgery, Univ, of Calif. Medical Center, Los Angeles, CA 90024 REFERENCES 1. Little JC: Direct laryngoscopy: A survey. Arch Otolaryngol 79:487-489, 1964
copy. Ann Otol Rhinol Laryngol 78:464-468, 1969
2. Proctor DF: Anesthesia for peroral endoscopy and bronchography. Anesthesiology 29:1025-1036,1968
5. Gaskill JR, Gillies DR: Local anesthesia for peroral endoscopy. Arch Otolaryngol 84: 654-657, 1966
3. Lejune E Jr, Welborn SG: The laryngoscopist's role in anesthesia for suspension laryngoscopy. South Med J 62:119-120, 1969 4. Atkins JP: Local anesthesia for endos-
6. Barton S, Williams JD: Glossopharyngeal nerve block. Arch Otolaryngol 93: 186189,1971 7. Jafek BW, Bauknight RS, Calcaterra TC: Percutaneous anesthesia for endoscopy. Arch Surg 104:658-661, 1972
Downloaded from aor.sagepub.com at CARLETON UNIV on June 27, 2015
LOCAL ANESTHESIA FOR SUSPENSION MICROLARYNGOSCOPY THOMAS
C.
CALCATERRA,
JAMES HOUSE,
Los
M.D.
M.D.
ANGELES, CALIFORNIA
SUMMARY - Despite the strong trend toward use of general anesthesia for laryngoscopy, local anesthesia retains inherent advantages from the standpoint of patient safety and maintenance of physiologic function of the larynx during endoscopy. Topical anesthesia produces incomplete sensory blockade and is unsatisfactory for suspension laryngoscopy. A method of infiltration anesthesia is described whereby profound anesthesia of the base of the tongue, valleculae, and larynx can be achieved to allow suspension laryngoscopy.
jection of an inert polymer paste is far more accurate when the vocal cords can be monitored during voluntary phonation.
During the development of peroral endoscopy, topical anesthesia was used almost exclusively; and as recently as 1962, 70% of those institutions replying to a questionnaire reported that local anesthesia was being used predominantly.! The past 20 years, however. have witnessed an increasing trend toward general anesthesia," based on its convenience of use and greater sophistication. Suspension laryngoscopy and the operating microscope have placed increasing reliance on general anesthe• 3 sia.
Among the disadvantages of local anesthetic when administered by the classical topical transmucosal route, the foremost is incomplete anesthesia, resulting in considerable distress to the patient and, thus, lack of cooperation during the procedure. The topical anesthetic method is time-consuming and requires a period of 15 to 20 minutes to achieve maximum effect,4 yet the duration of anesthesia may be insufficient to complete the entire endoscopic examination. The inconsistency of the effectiveness of topical anesthesia is largely the result of different absorption capacities of the alimentary and respiratory mucous membranes that may vary unpredictably in type from thin ciliated columnar to thick squamous epithelium. In addition. oropharyngeal secretions pooling in the hypopharynx interfere with the absorption of a topical anesthetic.
ADVANTAGES AND DISADVANTAGES OF LOCAL ANESTHESIA
The advantages of local anesthesia for endoscopy are numerous, the foremost clearly being increased safety, particularly with severely ill patients or those with pulmonary disease. Administration of local anesthetic obviates the prolonged postoperative denression that inhibits the normal cough reflex and predisposes the patient to aspiration and pneumonia. Furthermore, the patient can cough voluntarily during endoscopy to facilitate procurement of aspirates for bacteriologic and cytologic study. Local anesthesia does not result in the motor paralysis that makes impossible neuromuscular evaluation for the larynx and hyoooharynx, Thus, the treatment of paralytic dysphonia by in-
The dosage of topical anesthetic required to obtain satisfactory anesthesia often narrowly reaches the limits of safety. Topical anesthetic drugs applied to the respiratory epithelium characteristically are absorbed into the systemic
From the Department of Surgery, Division of Head and Neck Surgery, UCLA School of Medicine, Los Angeles, California.
71
Downloaded from aor.sagepub.com at CARLETON UNIV on June 27, 2015
CALCATERRA-HOUSE
72
circulation with the rapidity of an intravenous injection, thereby increasing the risk of serious drug toxicity. The addition of a vasoconstricting agent, such as epinephrine, does not significantly retard absorption of most anesthetic drugs.
Tonsil\ needle \
\
, , I':
I
METHODS AND MATERIAL
The ideal anesthetic would provide maximum anesthesia to the stimulated region with minimal absorption through other surfaces, avoiding the hazardous peaks of drug concentration in the systemic circulation. Based on the limitations of both general anesthesia and topical anesthesia for peroral endoscopy, regional nerve blocks were first utilized for this procedure at the UCLA Hospital in 1965. Initially, just the superior laryngeal nerves as they passed through the thyrohyoid membrane were blocked by bilateral percutaneous administration to the neck of 2 to 4 ml of lidocaine.f Intraoral blockade of the glossopharyngeal nerve was subsequently employed to supplement the anesthesia of the pharynx. 6 During the past seven years, more than 500 endoscopic examinations have been accomplished successfully with techniques that blockade the superior laryngeal nerve percutaneously and the glossopharyngeal nerve perorally." Occasionally, precise location of the superior laryngeal nerves was difficult, particularly in patients with short thick necks whose cartilaginous laryngeal landmarks could not easily be palpated. Other patients were encountered in whom adeauate anesthesia of the base of the tongue, valleculae, and epiglottis could not be obtained, despite apparent blockade of the superior laryngeal and glossopharyngeal nerves. Suspension microlaryngoscopy then proved to be impossible without general anesthesia because of discomfort at the base of the tongue and epiglottis. Careful questioning of our patients after laryngoscopy revealed that the distal tip of the laryngoscope was the source of most discomfort. A method was devised to provide maximum anesthesia of the base of the tongue and the supraglottic portion of the larynx sufficient to perform suspension laryngoscopy. TECHNIQUE
Premedication one hour prior to endoscopy usually consists of 100 mg of sodium pentobarbital (Nembutal) ,®ft 100 mg of meperidine hydrochloride (Demerol) ,®"ft and hydroxyzine hy-
Fig. 1. With the base of tongue elevated forward, small increments of lidocaine are infiltrated at the sites indicated.
drochloride (Atarax) .®"U At operation 5 to 10 mg of diazepam (Valium)®OOOO may be administered to supplement the premedication until slurred speech occurs. The neck is prepared for nerve block, and each superior laryngeal nerve is anesthetized at the thyrohyoid membrane with about 2 ml of 1% lidocaine hydrochloride. The glossopharyngeal nerve is blocked bilaterally with 1% lidocaine hydrochloride just behind the posterior tonsillar pillar at its midpoint superior inferiorly. If bronchoscopy is planned, 2 to 3 ml of 1% lidocaine hydrochloride are injected through the cricothyroid membrane into the tracheal lumen to provide topical anesthesia of the tracheobronchial tree. The endoscopist then moves to the head of the table and extends the patient's neck. Under headlight illumination, the base of the tongue is gently elevated with a broad-bladed metal tongue depressor held in the same fashion as a laryngoscope. This maneuver provides excellent exposure of the valleculae, hypopharynx, epiglottis, and pyriform fossae. With a long-angled tonsil needle with 1 em of exposed tip, small increments (less than 1 ml) of
" Abbott Laboratories, North Chicago, Ill . ee Winthrop Laboratories, New York, NY. .. 00 Roerig, New York, NY. , ........ Roche Laboratories, Nutley, NJ.
Downloaded from aor.sagepub.com at CARLETON UNIV on June 27, 2015
ANESTHESIA FOR MICROLARYNGOSCOPY
1% lidocaine are infiltrated across the base of the tongue, lingual surface of epiglottis, and the anterior aspect of each pyriform fossae (Fig. 1). Aspiration of the needle is always first attempted prior to injection to avoid intravascular administration of the anesthetic. Generally, less than 10 ml of 1% lidocaine are required to produce profound anesthesia of the base of the tongue, larynx, and pharynx. Patients may undergo complete endoscopic examination of these areas without discomfort, and most will tolerate suspension laryngoscopy as it is performed with the laryngoscope stabilized on a platform over the chest. Because of the complete anesthesia produced, the patient is not allowed to swallow for four hours. COMMENT
Jafek et ali detailed the neuroanatomy of the base of the tongue and hypopharynx and concluded that present understanding of the sensory func-
73
tion in this area is incomplete. Certainly, an extensive sensory pharyngeal plexus exists that receives efferents from both the glossopharyngeal and vagus nerves. Because it is probably impossible to anesthetize the glossopharyngeal area simply by blocking the posterior pharyngeal segment of the glossopharyngeal nerves, this method of local infiltration of the area most stimulated during laryngoscopy was devised. The technique was initially designed for Teflon® displacement of the unilateral paralyzed vocal cord when it is advantageous to have both hands free, to use magnification with suspension laryngoscopy, and, most importantly, to permit voluntary movement of the normal vocal cord. Our success with this approach led to the broader application for local endoscopy. We have found this method of anesthesia to be uniformly predictable, rapid, and readily tolerable by the patient.
Reprints: Thomas C. Calcaterra, M.D., Division of Head and Neck Surgery, Univ, of Calif. Medical Center, Los Angeles, CA 90024 REFERENCES 1. Little JC: Direct laryngoscopy: A survey. Arch Otolaryngol 79:487-489, 1964
copy. Ann Otol Rhinol Laryngol 78:464-468, 1969
2. Proctor DF: Anesthesia for peroral endoscopy and bronchography. Anesthesiology 29:1025-1036,1968
5. Gaskill JR, Gillies DR: Local anesthesia for peroral endoscopy. Arch Otolaryngol 84: 654-657, 1966
3. Lejune E Jr, Welborn SG: The laryngoscopist's role in anesthesia for suspension laryngoscopy. South Med J 62:119-120, 1969 4. Atkins JP: Local anesthesia for endos-
6. Barton S, Williams JD: Glossopharyngeal nerve block. Arch Otolaryngol 93: 186189,1971 7. Jafek BW, Bauknight RS, Calcaterra TC: Percutaneous anesthesia for endoscopy. Arch Surg 104:658-661, 1972
Downloaded from aor.sagepub.com at CARLETON UNIV on June 27, 2015
