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Remember the gum-elastic bougie at extubation
Remember the Gum-Elastic Bougie at Extubation Beemeth Robles, MD,* Jerome Hester, MD,? John G. Brock-Utne, MA, MD, PhD, FFA (SA)$ Department
of Anesthesia,
Although the use of a gum-elastic bougie to secure an airway is well &scribed, its use during extubation is not well documented. A bougie was passed through the endatracheal tube (ETT) prior to extubation in anticipation of possible reintubation of a patient with a d$ficult airway, Once the bougie was in place, the ETT was removed over it. Later, when the patient’s airway did become compromised, the trachea was rapidly reintubated using the bougie, without the need for direct laryngoscopy, fiberoptic bronchoscopy, or, worse, emergency tracheostomy.
Keywords:Airway obstruction; malformations; intratracheal.
bougie,
elastic;
arteriovenous intubation; extubation,
Introduction Various methods have been used to gain access to the difficult airway, including the gum-elastic bougie, first described by Robert Macintosh in 1949.’ For patients whose tracheas have been difficult to intubate, the optimum time to extubate the trachea can be difficult to determine. We report a case in which a bougie was placed in the trachea at the end of surgery but before the endotracheal tube (ETT) was removed. It was subsequently
*Resident in Anesthesia TResident in Otolaryngology SProfessor of Anesthesia Address reprint requests to Dr. Brock-Utne at the Department of Anesthesia, Stanford University School of Medicine, Stanford, CA 94305-5117, USA. Received for publication November 23, 1992; revised manuscript accepted for publication March 2, 1993. 0 1993 Butterworth-Heinemann
J. Clin. Anesth. 5:3f94iS1,1993
Stanford University School of Medicine, Stanford, CA.
used to secure the airway when the patient respiratory difficulties.
experienced
Case Report A 35-year-old, 60 kg woman presented for resection of a large facial arteriovenous malformation (AVM). She had had multiple previous attempts at excision and embolization without lasting success. The patient’s physical examination was remarkable for macroglossia, left cheek and left submandibular soft tissue growths causing obvious and pronounced facial asymmetry. The skin overlying the arteriovenous mass was thin, with injected vessels on the surface. Despite her physical appearance, the patient’s airway was not compromised. Her only medication was prednisone 10 mg to suppress the inflammation and reaction caused by the AVM, and thereby minimize the number of bleeding episodes she would develop from it. She had had a previous adverse reaction to meperidine, which manifested itself with postoperative nausea and vomiting, but otherwise had no known drug allergies. On the day of surgery, the patient was taken to the operating room and given methylprednisolone sodium succinate (Solu-medrol) 100 mg after intravenous (IV) access was established. Routine anesthetic monitoring with a pulse oximeter commenced. The patient’s last operation had been 2 months prior to this admission. At that time, the trachea had been visualized, and no anatomic abnormality had been identified. Direct laryngoscopy and orotracheal intubation with anesthesia had been accomplished without difficulty. During the present operation, we decided that fiberoptic intubation would most likely not be necessary, but in case it was, the patient’s oropharynx and hypopharynx were anesthetized with 5 ml of 10% lidocaine spray. After administration of midazolam 2 mg IV, direct laryngoscopy demonstrated visible epiglottis. We felt that after induction of general anesthesia and with muscle relaxation, tracheal intubation would be accomplished with relative ease. Our “difficult intubation” cart, containing a fiberoptic bronJ. Clin. Anesth.,
vol. 5, July/August
1993
329
Ca.seReports
choscope and other airway aids, was available in the room. Following preoxygenation, thiopental sodium 150 mg IV (2.5 mg/kg) was used for anesthetic induction. At that time, ventilation by mask became slightly more difficult but was maintained. Thereafter, succinylcholine 80 mg was administered, followed by an additional dose of thiopental 100 mg IV. Following succinylcholine injection, mask ventilation became exceedingly difficult, no air was heard entering the trachea through the pretracheal stethoscope, and no end-tidal carbon dioxide (ETCO*) was seen on the mass spectrometer. Laryngoscopy showed the epiglottis, but the vocal cords and arytenoids were not visible. The trachea was subsequently easily intubated blindly using a gum-elastic bougie. A 7.0 mm ETT was passed over the bougie, and placement was confirmed by auscultation, palpation of the cuff in the sternal notch, and the presence of ETCOp on the mass spectrometer. The patient’s oxygen saturation (SpOe) by pulse oximeter remained at 100% throughout this period. Anesthesia was maintained with nitrous oxide, oxygen (O,), 0.5% to 0.8% isoflurane, and fentanyl 350 kg, and muscle relaxation was provided with vecuronium 12 mg. The surgical procedure was carried out uneventfully. At the completion of the operation, the patient’s neuromuscular blockade was reversed. She was breathing spontaneously, and the ETT cuff was deflated to demonstrate a leak around the ETT.* Once the patient was sufficiently awake and responsive to command, our plan was to extubate her trachea. However, because of the difficulty encountered during the endotracheal intubation and the possibility of upper airway edema, a bougie was placed in the trachea through the ETT, and the tube was removed over it. Prior to this second bougie placement, the trachea was topically anesthetized via the ETT with 4 ml of 4% lidocaine. Following removal of the ETT, the patient was placed in a semisitting position. She appeared to breathe comfortably and maintained oxygenation despite having the bougie in place. This situation was taken to imply that we had not traumatized her airway during intubation. However, 10 minutes later, despite what were interpreted as adequate respiratory efforts (i.e., being able to create a reasonable volume without the use of accessory muscles), SpOp dropped to 96%. There was no evidence of residual neuromuscular blockade or narcotic effect. A few minutes later, the patient indicated on questioning that she could not get enough air into her lungs. We diagnosed an upper airway obstruction, most likely due to excess edema of the tongue and surrounding tissues. Two nasopharyngeal airways were placed to assist spontaneous ventilation, which improved clinically. SpOr remained at 96% to 97% on an inspired oxygen tension (FIOP) of 1.0. The patient was transported to the postoperative recovery room breathing 100% O2 by face mask. Upon her arrival in the recovery room, SpOz was 94%. An oral airway failed to improve oxygenation. During the next 5 minutes, SpOs slowly dropped to 90% despite an FIO:, 330
J. Clin. Anesth., vol. 5, July/August
1993
of 1.0. It became obvious that the tongue was becoming even more swollen, causing an upper airway obstruction and severely compromising respiration. The patient indicated, by pointing her finger to her throat, that she was getting very little air. She was in obvious distress. We therefore decided to reintubate the trachea using the bougie already in place in the trachea. A 6.0 mm ETT was passed with ease over the bougie and into the trachea. The bougie was withdrawn. The patient was initially assisted with positive-pressure ventilation. Auscultation of the chest confirmed satisfactory ETT placement. With the patient spontaneously breathing 100% Or via a T-piece, SpOr returned to 100%. A portable chest radiograph showed no change from the one taken preoperatively, and arterial blood gases measured pH 7.33 PaO:, 213 mmHg, PaCOr 45 mmHg, and bicarbonate 23.6. The patient was given additional steroids, Solumedrol 125 mg followed by Dexamethasone 6 mg, in the hope of decreasing tongue and upper airway swelling. Her trachea was left intubated overnight in the intensive care unit while she breathed spontaneously. The next morning, the edema seemed clinically subsided, and since arterial blood gases had normalized, the ETT was removed without further incident. Later that day, the patient was discharged home.
Discussion The successful management of a difficult intubation using a gum-elastic bougie or ETT introducer (Downs Surgical, Inc. Decatur, GA) has been highlighted in several reports.g-6 Its use to secure a potentially difficult and precarious airway in the postoperative period has not, to our knowledge, previously been reported. We report here a patient who was more difficult to intubate than anticipated, and because of the surgery and the large facial AVM, we were concerned about the optimum time of extubating the trachea. At the end of the anesthetic, the plan was to be sure that she was awake and able to maintain an airway. Once the patient had awakened and the neuromuscular blockade was fully reversed, she demonstrated good strength and was able to breathe around an occluded ETT with the cuff deflated.* Thus, we decided to extubate her trachea. We felt that this decision was appropriate because of the relatively short surgical procedure (2 hours 15 minutes) and because the facial swelling did not seem clinically different from its preoperative state, nor were any large vessels ligated, thereby possibly altering venous return. Finally, the patient had been placed in the semisitting position intraoperatively. Thus, when considering all the factors involved, it seemed prudent to extubate her trachea, especially since she was scheduled to go home later that day. However, we were concerned about the possible need for reintubation, which could prove to be very diffcult should it be required immediately. A nasal airway, along with simple maneuvers such as the chin lift or jaw thrust, could have been used to assist spontaneous ventilation if the upper airway became compromised. This would have been an excellent option for
The gum-elastic bougie at extubation: Robles et al.
a patient with normal facial, oral, and pharyngeal anatomy, but not for our patient. Other means of reestablishing an airway could have included a light wand’ or a gum-elastic bougie with the assistance of direct laryngosc~py.~p~,~In 1987, Bedger and Ghan@ described a technique for intubation using direct laryngoscopy with a jet-stylet catheter (hollow), which has the added benefit of allowing jet ventilation of the patient’s lungs. Other methods have been described with a laryngeal mask and gum-elastic bougie.g In a more controlled situation, one also could have opted for fiberoptic guidance, as well as other well-described techniques.iO Bronchial tears have been described with plastic guides and bougies when used blindly in the airway. I1 However, when used with care, the bougie is a valuable tool when securing a diflicult airway is urgent. In a recent study comparing endotracheal intubation by direct vision with or without a gum-elastic bougie, no difference in the occurrence of postoperative sore throat and hoarseness could be detected between the two groups.” We have described a patient who we thought could develop upper airway obstruction postoperatively. This was managed by leaving a gum-elastic bougie (via the ETT) in place in the trachea after the ETT had been removed. This approach allowed rapid reintubation without the need for direct laryngoscopy. The reintubation was accomplished atraumatically and swiftly by passing a 6.0 mm ETT over the bougie and into the trachea, thereby securing the airway.
References 1. Macintosh RR: An aid to oral intubation. Br Med J 1949;1:28. 2. Fisher MM, Raper RF: The “cuff-leak” test for extubation. Anaesthesia 1992;47: 10-2. 3. Dogra S, Falconer R, Latto IP: Successful difficult intubation. Tracheal tube placement over a gum-elastic bougie. Anaesthesia 1990;45:774-6. 4. Kidd JF, Dyson A, Latto IP: Successful difficult intubation. Use of the gum elastic bougie. Anaesthesia 1988;43:437-8. 5. McCarroll SM, Lamont BJ, Buckland MR, Yates AP: The gumelastic bougie: old but still useful [Letter]. An&&o&y 1988;68:643-4. 6. Benson PF: The gum-elastic bougie: a life saver [Letter]. Anesth Analg 1992;74:318. 7. Stewart RD, LaRosee A, Stoy WA, Heller MB: Use of a lighted stylet to confirm correct endotracheal tube placement. Chest 1987;92:900-3. 8. Bedger RC Jr, Chang JL: A jet-stylet endotracheal catheter for difficult airway management. Anesthesiology 1987;66:221-3. 9. Allison A, McCrory J: Tracheal placement of a gum elastic bougie using the laryngeal mask airways. [Letter]. Anaesthesia 1990;45:419-20. 10. Benumof JL: Management of the difficult adult airway. With special emphasis on awake tracheal intubation. Anesthesiolo~ 1991;75:1087-110. 11. Conacher ID: Instrumental bronchial tears. Anaesthesia 1992;47:589-90. 12. Nolan JP, Wilson ME: An evaluation of the gum elastic bougie. Intubation times and incidence of sore throat. Anwsthka 1992;47:878-81.
Anesthesia History Quiz-Answers Quiz based upon: Bacon DR, Lema MJ: To define a specialty: A brief history of the American Board of Anesthesiology’s first written examination. J Clin An&h 4:489-497, 1992, and Bacon DR, Lema MJ, Yearley CK: For all the world to see: Anesthesia at the 1939 Worlds Fair. J Clin Anesth 5:251-258, 1993. (Quiz appeared on page 258 in the May/June 1993 issue.) 1. University of Wisconsin, Madison, Wisconsin. of George Washington’s inauguration as President of 2. The 150th anniversary the United States. 13, 1936. 3. February 4. The Canadian Society of Anesthetists, the Pacific Coast Association of Anesthetists, the Southern Association of Anesthetists, the Eastern Society of Anesthetists, the Mid-Western Society of Anesthetists, the Associated Anesthetists of America, the Associated Anesthetists of the United States and Canada, the National Anesthesia Research Society, and the International Anesthesia Research Society. 5. Flower and Fifth Avenue. 6. Meyer Sakland changed the format from essay to multiple choice. 7. The Mayo Clinic (John Lundy). 8. Paul M. Wood, M.D. Library-Museum of Anesthesiology, 520 N. Northwest Highway, Park Ridge, Illinois (within the headquarters of the American Society of Anesthesiologists). 9. The Associated Anesthetists of America founded in 1912. 10. ABA 1.5 years, ASA 3.5 years, ICA 6 years, IARS 17 years.
J. Clin. Anesth.,
vol. 5, July/August
1993
331
of Anesthesia,
Although the use of a gum-elastic bougie to secure an airway is well &scribed, its use during extubation is not well documented. A bougie was passed through the endatracheal tube (ETT) prior to extubation in anticipation of possible reintubation of a patient with a d$ficult airway, Once the bougie was in place, the ETT was removed over it. Later, when the patient’s airway did become compromised, the trachea was rapidly reintubated using the bougie, without the need for direct laryngoscopy, fiberoptic bronchoscopy, or, worse, emergency tracheostomy.
Keywords:Airway obstruction; malformations; intratracheal.
bougie,
elastic;
arteriovenous intubation; extubation,
Introduction Various methods have been used to gain access to the difficult airway, including the gum-elastic bougie, first described by Robert Macintosh in 1949.’ For patients whose tracheas have been difficult to intubate, the optimum time to extubate the trachea can be difficult to determine. We report a case in which a bougie was placed in the trachea at the end of surgery but before the endotracheal tube (ETT) was removed. It was subsequently
*Resident in Anesthesia TResident in Otolaryngology SProfessor of Anesthesia Address reprint requests to Dr. Brock-Utne at the Department of Anesthesia, Stanford University School of Medicine, Stanford, CA 94305-5117, USA. Received for publication November 23, 1992; revised manuscript accepted for publication March 2, 1993. 0 1993 Butterworth-Heinemann
J. Clin. Anesth. 5:3f94iS1,1993
Stanford University School of Medicine, Stanford, CA.
used to secure the airway when the patient respiratory difficulties.
experienced
Case Report A 35-year-old, 60 kg woman presented for resection of a large facial arteriovenous malformation (AVM). She had had multiple previous attempts at excision and embolization without lasting success. The patient’s physical examination was remarkable for macroglossia, left cheek and left submandibular soft tissue growths causing obvious and pronounced facial asymmetry. The skin overlying the arteriovenous mass was thin, with injected vessels on the surface. Despite her physical appearance, the patient’s airway was not compromised. Her only medication was prednisone 10 mg to suppress the inflammation and reaction caused by the AVM, and thereby minimize the number of bleeding episodes she would develop from it. She had had a previous adverse reaction to meperidine, which manifested itself with postoperative nausea and vomiting, but otherwise had no known drug allergies. On the day of surgery, the patient was taken to the operating room and given methylprednisolone sodium succinate (Solu-medrol) 100 mg after intravenous (IV) access was established. Routine anesthetic monitoring with a pulse oximeter commenced. The patient’s last operation had been 2 months prior to this admission. At that time, the trachea had been visualized, and no anatomic abnormality had been identified. Direct laryngoscopy and orotracheal intubation with anesthesia had been accomplished without difficulty. During the present operation, we decided that fiberoptic intubation would most likely not be necessary, but in case it was, the patient’s oropharynx and hypopharynx were anesthetized with 5 ml of 10% lidocaine spray. After administration of midazolam 2 mg IV, direct laryngoscopy demonstrated visible epiglottis. We felt that after induction of general anesthesia and with muscle relaxation, tracheal intubation would be accomplished with relative ease. Our “difficult intubation” cart, containing a fiberoptic bronJ. Clin. Anesth.,
vol. 5, July/August
1993
329
Ca.seReports
choscope and other airway aids, was available in the room. Following preoxygenation, thiopental sodium 150 mg IV (2.5 mg/kg) was used for anesthetic induction. At that time, ventilation by mask became slightly more difficult but was maintained. Thereafter, succinylcholine 80 mg was administered, followed by an additional dose of thiopental 100 mg IV. Following succinylcholine injection, mask ventilation became exceedingly difficult, no air was heard entering the trachea through the pretracheal stethoscope, and no end-tidal carbon dioxide (ETCO*) was seen on the mass spectrometer. Laryngoscopy showed the epiglottis, but the vocal cords and arytenoids were not visible. The trachea was subsequently easily intubated blindly using a gum-elastic bougie. A 7.0 mm ETT was passed over the bougie, and placement was confirmed by auscultation, palpation of the cuff in the sternal notch, and the presence of ETCOp on the mass spectrometer. The patient’s oxygen saturation (SpOe) by pulse oximeter remained at 100% throughout this period. Anesthesia was maintained with nitrous oxide, oxygen (O,), 0.5% to 0.8% isoflurane, and fentanyl 350 kg, and muscle relaxation was provided with vecuronium 12 mg. The surgical procedure was carried out uneventfully. At the completion of the operation, the patient’s neuromuscular blockade was reversed. She was breathing spontaneously, and the ETT cuff was deflated to demonstrate a leak around the ETT.* Once the patient was sufficiently awake and responsive to command, our plan was to extubate her trachea. However, because of the difficulty encountered during the endotracheal intubation and the possibility of upper airway edema, a bougie was placed in the trachea through the ETT, and the tube was removed over it. Prior to this second bougie placement, the trachea was topically anesthetized via the ETT with 4 ml of 4% lidocaine. Following removal of the ETT, the patient was placed in a semisitting position. She appeared to breathe comfortably and maintained oxygenation despite having the bougie in place. This situation was taken to imply that we had not traumatized her airway during intubation. However, 10 minutes later, despite what were interpreted as adequate respiratory efforts (i.e., being able to create a reasonable volume without the use of accessory muscles), SpOp dropped to 96%. There was no evidence of residual neuromuscular blockade or narcotic effect. A few minutes later, the patient indicated on questioning that she could not get enough air into her lungs. We diagnosed an upper airway obstruction, most likely due to excess edema of the tongue and surrounding tissues. Two nasopharyngeal airways were placed to assist spontaneous ventilation, which improved clinically. SpOr remained at 96% to 97% on an inspired oxygen tension (FIOP) of 1.0. The patient was transported to the postoperative recovery room breathing 100% O2 by face mask. Upon her arrival in the recovery room, SpOz was 94%. An oral airway failed to improve oxygenation. During the next 5 minutes, SpOs slowly dropped to 90% despite an FIO:, 330
J. Clin. Anesth., vol. 5, July/August
1993
of 1.0. It became obvious that the tongue was becoming even more swollen, causing an upper airway obstruction and severely compromising respiration. The patient indicated, by pointing her finger to her throat, that she was getting very little air. She was in obvious distress. We therefore decided to reintubate the trachea using the bougie already in place in the trachea. A 6.0 mm ETT was passed with ease over the bougie and into the trachea. The bougie was withdrawn. The patient was initially assisted with positive-pressure ventilation. Auscultation of the chest confirmed satisfactory ETT placement. With the patient spontaneously breathing 100% Or via a T-piece, SpOr returned to 100%. A portable chest radiograph showed no change from the one taken preoperatively, and arterial blood gases measured pH 7.33 PaO:, 213 mmHg, PaCOr 45 mmHg, and bicarbonate 23.6. The patient was given additional steroids, Solumedrol 125 mg followed by Dexamethasone 6 mg, in the hope of decreasing tongue and upper airway swelling. Her trachea was left intubated overnight in the intensive care unit while she breathed spontaneously. The next morning, the edema seemed clinically subsided, and since arterial blood gases had normalized, the ETT was removed without further incident. Later that day, the patient was discharged home.
Discussion The successful management of a difficult intubation using a gum-elastic bougie or ETT introducer (Downs Surgical, Inc. Decatur, GA) has been highlighted in several reports.g-6 Its use to secure a potentially difficult and precarious airway in the postoperative period has not, to our knowledge, previously been reported. We report here a patient who was more difficult to intubate than anticipated, and because of the surgery and the large facial AVM, we were concerned about the optimum time of extubating the trachea. At the end of the anesthetic, the plan was to be sure that she was awake and able to maintain an airway. Once the patient had awakened and the neuromuscular blockade was fully reversed, she demonstrated good strength and was able to breathe around an occluded ETT with the cuff deflated.* Thus, we decided to extubate her trachea. We felt that this decision was appropriate because of the relatively short surgical procedure (2 hours 15 minutes) and because the facial swelling did not seem clinically different from its preoperative state, nor were any large vessels ligated, thereby possibly altering venous return. Finally, the patient had been placed in the semisitting position intraoperatively. Thus, when considering all the factors involved, it seemed prudent to extubate her trachea, especially since she was scheduled to go home later that day. However, we were concerned about the possible need for reintubation, which could prove to be very diffcult should it be required immediately. A nasal airway, along with simple maneuvers such as the chin lift or jaw thrust, could have been used to assist spontaneous ventilation if the upper airway became compromised. This would have been an excellent option for
The gum-elastic bougie at extubation: Robles et al.
a patient with normal facial, oral, and pharyngeal anatomy, but not for our patient. Other means of reestablishing an airway could have included a light wand’ or a gum-elastic bougie with the assistance of direct laryngosc~py.~p~,~In 1987, Bedger and Ghan@ described a technique for intubation using direct laryngoscopy with a jet-stylet catheter (hollow), which has the added benefit of allowing jet ventilation of the patient’s lungs. Other methods have been described with a laryngeal mask and gum-elastic bougie.g In a more controlled situation, one also could have opted for fiberoptic guidance, as well as other well-described techniques.iO Bronchial tears have been described with plastic guides and bougies when used blindly in the airway. I1 However, when used with care, the bougie is a valuable tool when securing a diflicult airway is urgent. In a recent study comparing endotracheal intubation by direct vision with or without a gum-elastic bougie, no difference in the occurrence of postoperative sore throat and hoarseness could be detected between the two groups.” We have described a patient who we thought could develop upper airway obstruction postoperatively. This was managed by leaving a gum-elastic bougie (via the ETT) in place in the trachea after the ETT had been removed. This approach allowed rapid reintubation without the need for direct laryngoscopy. The reintubation was accomplished atraumatically and swiftly by passing a 6.0 mm ETT over the bougie and into the trachea, thereby securing the airway.
References 1. Macintosh RR: An aid to oral intubation. Br Med J 1949;1:28. 2. Fisher MM, Raper RF: The “cuff-leak” test for extubation. Anaesthesia 1992;47: 10-2. 3. Dogra S, Falconer R, Latto IP: Successful difficult intubation. Tracheal tube placement over a gum-elastic bougie. Anaesthesia 1990;45:774-6. 4. Kidd JF, Dyson A, Latto IP: Successful difficult intubation. Use of the gum elastic bougie. Anaesthesia 1988;43:437-8. 5. McCarroll SM, Lamont BJ, Buckland MR, Yates AP: The gumelastic bougie: old but still useful [Letter]. An&&o&y 1988;68:643-4. 6. Benson PF: The gum-elastic bougie: a life saver [Letter]. Anesth Analg 1992;74:318. 7. Stewart RD, LaRosee A, Stoy WA, Heller MB: Use of a lighted stylet to confirm correct endotracheal tube placement. Chest 1987;92:900-3. 8. Bedger RC Jr, Chang JL: A jet-stylet endotracheal catheter for difficult airway management. Anesthesiology 1987;66:221-3. 9. Allison A, McCrory J: Tracheal placement of a gum elastic bougie using the laryngeal mask airways. [Letter]. Anaesthesia 1990;45:419-20. 10. Benumof JL: Management of the difficult adult airway. With special emphasis on awake tracheal intubation. Anesthesiolo~ 1991;75:1087-110. 11. Conacher ID: Instrumental bronchial tears. Anaesthesia 1992;47:589-90. 12. Nolan JP, Wilson ME: An evaluation of the gum elastic bougie. Intubation times and incidence of sore throat. Anwsthka 1992;47:878-81.
Anesthesia History Quiz-Answers Quiz based upon: Bacon DR, Lema MJ: To define a specialty: A brief history of the American Board of Anesthesiology’s first written examination. J Clin An&h 4:489-497, 1992, and Bacon DR, Lema MJ, Yearley CK: For all the world to see: Anesthesia at the 1939 Worlds Fair. J Clin Anesth 5:251-258, 1993. (Quiz appeared on page 258 in the May/June 1993 issue.) 1. University of Wisconsin, Madison, Wisconsin. of George Washington’s inauguration as President of 2. The 150th anniversary the United States. 13, 1936. 3. February 4. The Canadian Society of Anesthetists, the Pacific Coast Association of Anesthetists, the Southern Association of Anesthetists, the Eastern Society of Anesthetists, the Mid-Western Society of Anesthetists, the Associated Anesthetists of America, the Associated Anesthetists of the United States and Canada, the National Anesthesia Research Society, and the International Anesthesia Research Society. 5. Flower and Fifth Avenue. 6. Meyer Sakland changed the format from essay to multiple choice. 7. The Mayo Clinic (John Lundy). 8. Paul M. Wood, M.D. Library-Museum of Anesthesiology, 520 N. Northwest Highway, Park Ridge, Illinois (within the headquarters of the American Society of Anesthesiologists). 9. The Associated Anesthetists of America founded in 1912. 10. ABA 1.5 years, ASA 3.5 years, ICA 6 years, IARS 17 years.
J. Clin. Anesth.,
vol. 5, July/August
1993
331