Anesthesia for Prolonged Bronchoscopy Lawrence B. Perry, M.D., and David R. Sanderson, M.D.
ABSTRACT At the Mayo Clinic, experience with 22 patients undergoing bronchoscopy on 29 occasions has shown that prolonged operative manipuktion in the airway can be carried out safely and satisfactorily using general anesthesia. Requisites for this procedure include a period of apneic oxygenation, an adequate-sizedendotracheal tube, hyperventilationof the patient during operativemanipulation, and careful attention to management of postoperative bronchospasm. Prolonged bronchoscopy under general anesthesia has permitted localizationof occult bronchogeniccarcinomaat an earlier stage than has been possible up to this point.
R
ecent experience from the Mayo Lung Project, a lung cancer screening program sponsored by the National Cancer Institute, has permitted recognition of early bronchogenic carcinoma in a series of high-risk subjects on the basis of changes seen in thoracic roentgenograms and by sputum cytology [7]. Disease has been recognized from sputum cytology in an appreciable number of patients before any roentgenographic sign of localization was present [13]. In some of these patients a cursory bronchoscopic examination following topical anesthesia was adequate to permit localization and to direct therapy. However, initial bronchoscopy to identify gross mucosal lesions often was inadequate. Precise endoscopic localization must be accomplished if early treatment is to be offered these patients with roentgenographically occult lung cancer. A procedure has been developed by the Cooperative Lung Cancer Detection Task Force of the National Cancer Institute to localize the source of exfoliated cancer cells in these patients with normal findings on chest roentgenograms [ 131. However, the long time necessary for this detailed examination, often in excess of 2 hours, makes procedures that involve topical anesthesia unsatisfactory. In addition, repeated bronchoscopic examinations are often necessary, for which the patient usually prefers general anesthesia. The delivery and maintenance of safe endotracheal anesthesia while the airway is variously compromised by an assortment of rigid and fiberoptic instruments present a challenge to both the anesthesiologist and the endoscopist. Furthermore, the patients at risk for bronchogenic carcinoma are in an age group
From the Mayo Clinic and Mayo Foundation, Rochester, Minn. Accepted for publication Oct. 14, 1974. Supported in part by Research Contract CB-22000 from the National Institutes of Health, U.S. Public Health Service. Address reprint requests to Dr. Perry, Mayo Clinic, Rochester, Minn. 55901.
248
T H E ANNALS OF THORACIC SURGERY
Anesthesia for Prolonged Bronchoscopy that shares increased danger from coronary heart disease, chronic obstructive pulmonary disease, and other problems of aging. The purpose of this paper is to describe our methods of general anesthesia and the results obtained with these techniques.
Methods A description of the endoscopic procedure is necessary for understanding our anesthetic technique. This procedure can be divided into two phases. The first involves brief use of the open rigid bronchoscope, during which washings are obtained selectively from the left and right sides of the bronchial tree. The second is prolonged fiberoptic bronchoscopy involving videoscopic and photographic documentations, specimen collection by multiple brushings, and biopsy specimen collection from selective random sites. The rigid ventilating bronchoscope (ACMI, 8 mm by 40 cm) has no lateral vents in the distal end and employs an inflatable rubber cuff to provide an airtight seal in the bronchus or trachea. The bronchofiberscope (Olympus BF-5B, 5.5 mm) is inserted through a plastic endotracheal tube through a special closed T-adapter. Our present anesthetic technique has been developed to provide adequate oxygenation and ventilation as well as adequate anesthesia and relaxation. After several minutes of oxygenation, anesthesia is induced with thiopental and continued with halothane or enflurane in oxygen by mask for 10 to 15 minutes; nitrous oxide is not used at this time. Direct laryngoscopy is then performed with the aid of succinylcholine,and the vocal cords and trachea are sprayed with 4.0 ml of 4% lidocaine. Relaxation is maintained with the use of either 0.2% succinylcholine infusion or pancuronium bromide. After application of the topical anesthetic, the endoscopist inserts the open rigid bronchoscope into the trachea and the lungs are ventilated for 1 to 2 minutes. The bronchoscope is then inserted into the left main bronchus, the cuff is inflated, ventilation is stopped, and washings are obtained during a 1%- to 2-minute period. The cuff is deflated, the bronchoscope is moved back into the trachea, and ventilation is resumed for several minutes. Then the bronchoscope is repositioned in the right main bronchus and the cuff is inflated for selective washing on that side. The rigid bronchoscope is subsequently removed, and the patient is reintubated with a 10 mm ID plastic endotracheal tube. Fifty percent nitrous oxide is added to the anesthetic mixture, and ventilation is controlled for the duration of the procedure. Arterial blood gases are measured periodically to assess the effectiveness of ventilation. The patient is monitored continuously with a precordial stethoscope and an electrocardiographic oscilloscope. At the conclusion of the procedure, anesthesia is discontinued and the patient is allowed to awaken. The muscle relaxants are not reversed, and the endotracheal tube is left in for continued assisted or controlled ventilation. The F I O ~ and ventilation are adjusted as indicated by blood gas measurements, and the patient is extubated when he has recovered sufficiently from the effects of the procedure.
VOL. 19, NO. 3, MARCH, 1975
249
PERRY AND SANDERSON
Results This procedure has been performed 29 times on 22 different patients. Of the 22 patients, 17 were examined once, 3 were examined twice, and 2 were examined three times. All of the patients were men. The average age was 62 years(range 46 to 77), and the average duration of the procedure was 130 minutes (range 45 to 195). Halothane was used as the primary anesthetic in 9 patients, enflurane in 14, Innovar in 2, and thiopental in 4. Relaxation was maintained with succinylcholine in 19 cases and with pancuronium bromide in 8; 2 patients did not receive relaxants. There was 1 intraoperative complication: severe, persistent multifocal ventricular extrasystoles in a patient with known heart disease. Eight of the patients had significant bronchospasm in the recovery ward; 3 required therapy with intravenously administered aminophylline. In 19 of the 22 patients the primary malignancy was localized and treated. Seventeen had bronchogenic carcinoma of the squamous cell type, 1 had carcinoma at the base of the tongue, and 1 had carcinoma of the right vocal cord. The lesions in the latter 2 patients were identified by suspension laryngoscopy done in conjunction with the bronchoscopic examination. Of the 17 patients with lung cancer who were treated, 16 had operative resection and 1 had radiation therapy for a lesion in the carina and distal trachea. Of those undergoing resection, 14 had stage I squamous cell carcinoma and 2 had stage 111, according to the Staging Classification of the American Joint Committee on Cancer Staging and End Results Reporting. Both patients with upper airway lesions were treated: 1 (with the vocal cord lesion) was treated by cautery excision of the lesion and the other (with the lesion at the base of the tongue) by radiation therapy. Of the 3 untreated patients, 2 had lateralization accomplished on the basis of differential washings, but definitive treatment awaits more precise localization of the lesion by repeated bronchoscopy. The remaining patient had squamous cell metaplasia with marked atypia on initial sputum examinations, but all subsequent samples of washings and brushings showed mild to moderate atypia only. We regard this patient as not having frank lung cancer at the present time.
Comment Bronchoscopic examination is a vital part of the diagnostic and preoperative assessment of patients with bronchogenic carcinoma. Direct access to the tracheobronchial tree permits inspection, collection of secretions, and sampling by means of brush, curette, and forceps biopsy. To accomplish this with minimal hazard and discomfort to the patient, various techniques for topical and general anesthesia have been employed [ l , 111. Although adequacy of ventilation during bronchoscopy performed under topical anesthesia has rarely been a problem, such is not true with general anesthetic techniques. The problem of adequate ventilation and oxygenation has been appreciable, resulting in various methods and approaches [ 3 , 5 , 6 , 8 , 12, 141. These have generally involved a technique of light general anesthesia with intravenous muscle relaxants and controlled ventilation through a ventilating bronchoscope, a small endotracheal tube, or, more recently, some variant of the positive-pressure injector (Venturi) system. The 250
THE ANNALS OF THORACIC SURGERY
Anesthesia for Prolonged Bronchoscopy
recent development of fiberoptic bronchoscopes and their widespread employment have resulted in a resurgence of topical anesthetic techniques, with and without intravenous sedation, and the administration of general anesthesia with controlled ventilation through an endotracheal tube that is also used as a conduit for the bronchofiberscope [2, 4,151. The relatively brief time required for most examinations has made all these methods acceptable and applicable. The anesthetic requirements for a prolonged and complicated bronchoscopic procedure include those common to other peroral endoscopic techniques plus several that are peculiar to this procedure. The initial period of bronchial washing entails the problem of one lung at a time being alternately flooded with physiological solutions and aspirated while the other lung is totally bypassed by the bronchoscope. N o ventilation is possible during the washing of each lung, but we have been able to handle this satisfactorily by using apneic oxygenation. The usual attention to adequate ventilation requires more vigilance because of the demands of the procedure and the restriction of the air passage by the bronchoscope as well as by the endotracheal tube. It has been established that an endotracheal tube of 8.5 mm ID is the smallest through which the fiberoptic bronchoscope can be passed without unduly raising the resistance to air flow 19, 101. This is well illustrated in the Figure, which shows the resistance to increasing air flows through various sizes of endotracheal tubes with the 6 mm bronchofiberscope inserted. Even with a tube of 10 mm ID, which we use routinely, the resistance to air flow is higher than through a tube of 8.0 mm ID without the bronchofiberscope inserted. In addition, the presence of the bronchoscope in the various subdivisions of the bronchial tree further obstructs ventilation. The anesthesiologist must be continually aware that normal ventilatory support often is inadequate, and the Paco, should be checked periodically. Blood gas data (as summarized from 7 patients) reveal that Pa% values remain high after the two periods of apneic oxygenation, whereas Paco2 values are moderately increased, as would be expected (Table). Thereafter, during Air flow through various endotracheal tubes with or without insertion of bronchofiberscope 6 mm in diameter.
70
t
/
emm tube
/
9.omm tube 9.5 mm tube
emm tube without bronchofiberscope .2
I .4
.6
I
4.0
4:s
2:o
.8
Flow, L/s VOL. 19, NO. 3, MARCH, 1975
25 1
n
En
s
-I
8
78 76 59 74 57 65 77
37 41 39 39 38 34 40
Pa,.,,,
7.40
7.46 7.42 7.36 7.40 7.32 7.43 7.40
pH
'In millimeters of mercury. 'Fk,, = 0.40. 3Fki, = 0.33.
Mean 69.4 38.3
3 4 5 6 7
2
1
Patient No. Pao,
Patient Awake (Fk),= 0.21) pH 7.28 7.30 7.20 7.36 7.33 7.38 7.31 7.31
Pa,,,, 57 55 60 40 34 38 49 47.6
346 427 1362 359 467 1363 445
33 1
Pao,
After Bronchial Washings (Fk,, = 0.97)
251
174 239 79 156 268 92 249
Pao,
45.6
45 55 56 46 38 37 42
Pa, O1
Fiberscopy of 30 Minutes (Fq), =0.50)
7.33
7.35 7.29 7.22 7.30 7.37 7.42 7.33
pH
171
91 193 23 1 90 230
222
139
Pa,,,
7.35
7.35 7.34 7.32 7.36 7.36 7.42 7.30
45 44 44 40 36 33 51 41.9
pH
Pa,,,,
Fiberscopy of 60 Minutes (Fk), = 0.50)
107
98 63 106 82 120 112 171
Pao,
7.27
7.24 7.26 7.16 7.33 7.19 7.42 7.29
63 62 68 45 55 39 50 54.6
pH Pa,.,,,
Recovery Room (Fk,, = 0.40)
ARTERIAL BLOOD GAS DATA' ON 7 PATIENTS UNDERGOING PROLONGED BRONCHOSCOPY
Anesthesia for Prolonged Bronchoscopy fiberoptic bronchoscopy, oxygenation is also well maintained, but ventilation may tend to be somewhat inadequate. Halothane and enflurane are used as our main anesthetic agents because of their rapid action, nonflammability, and lack of bronchial irritation. Methoxyflurane has not been used because of the length of the induction procedure and because it does not supply the fairly deep anesthesia that is required. Isoflurane, when available, may be undesirable if there is bronchospasm, which has been reported to occur occasionally with its use.* Currently we prefer pancuronium bromide for relaxation because it seems to give a smoother anesthetic state than does intermittent-drip succinylcholine. Many patients experience bronchospasm in the recovery room. In some this is significant, with resulting respiratory acidosis; in a few it is severe enough to warrant bronchodilator therapy in addition to ventilatory support. Bronchospasm is enough of a problem that we leave the patient intubated and on a mechanical ventilator in the postanesthesia recovery room until he can safely care for himself (usually 1 to 3 hours).
References 1. Adriani, J. Anesthesia for endoscopy. Ann Otol Rhinol Laryngol 78:1129, 1969. 2. Barson, P. K., Scott, M. L., Martin, J. T., and Ochsner, J. L. Flexible fiberoptic bronchoscopy using general anesthesia: An improved technic. Anesth Analg (Cleve) 52:619, 1973. 3. Benson, D. W. A survey of general anesthesia for endoscopy. Ann Otol Rhinol Lalyngol 78:459, 1969. 4. Britton, R. M., and Nelson, K. G. Iniproper oxygenation during bronchofiberscopy. Anesthesiology 40:87, 1974. 5. Carden, E. Positive-pressure ventilation during anesthesia for bronchoscopy: A laboratory evaluation of two recent advances. Anesth Analg (Cleve) 52:402, 1973. 6. Foldes, F. F., and Maisel, W. Neuroleptanalgesia for peroral endoscopy. Arch Otolalyngol 91:280, 1970. 7. Fontana, R. S., Sanderson, D. R., Miller, W. E., Woolner, L. B., Taylor, W. F., and Uhlenhopp, M. A. The Mayo Lung Project: Preliminary report of “early cancer detection” phase. Cancer 30:1373, 1972. 8. Ciesecke, A. H.,Jr., Gerbershagen, H. U., Dortman, C., and Lee, D. Comparison of the ventilating and injection bronchoscopes. Anesthesiology 38:298, 1973. 9. Grossman, E., and Jacobi, A. M. Minimal optimal endotracheal tube size for fiberoptic bronchoscopy. Anesth Analg (Cleve) 53:475, 1974. 10. Perry, L. B. Discussion. In P. R. Raj, J. Forestner, T. D. Watson, R. E. Morris, and M. T.Jenkins, Technics for fiberoptic laryngoscopy in anesthesia. Anesth Analg (Cleve) 53:708, 1974. 1 1. Proctor, D. F. Anesthesia for peroral endoscopy and bronchography. Anesthesiology 29: 1025, 1968. 12. Sanders, R. D. Two ventilating attachments for bronchoscopes. Del Med J 39:170, 1967. 13. Sanderson, D. R., Fontana, R. S., Woolner, L. B., Bernatz, P. E., and Payne, W. S. Bronchoscopic localization of radiographically occult lung cancer. Chest 65:608, 1974. 14. Smith, F. R., Kundahl, P. C., and Fouty, R. The safety of general anesthesia for bronchoscopy demonstrated by a study of arterial and venous oxygen saturation levels. D k Chest 51:53, 1967. 15. Tahir, A. H. General anesthesia for bronchofiberscopy. Anesthesiology 37:564, 1972. *D. R. Krabill, personal communication, 1974.
VOL. 19, NO. 3, MARCH, 1975
253
ABSTRACT At the Mayo Clinic, experience with 22 patients undergoing bronchoscopy on 29 occasions has shown that prolonged operative manipuktion in the airway can be carried out safely and satisfactorily using general anesthesia. Requisites for this procedure include a period of apneic oxygenation, an adequate-sizedendotracheal tube, hyperventilationof the patient during operativemanipulation, and careful attention to management of postoperative bronchospasm. Prolonged bronchoscopy under general anesthesia has permitted localizationof occult bronchogeniccarcinomaat an earlier stage than has been possible up to this point.
R
ecent experience from the Mayo Lung Project, a lung cancer screening program sponsored by the National Cancer Institute, has permitted recognition of early bronchogenic carcinoma in a series of high-risk subjects on the basis of changes seen in thoracic roentgenograms and by sputum cytology [7]. Disease has been recognized from sputum cytology in an appreciable number of patients before any roentgenographic sign of localization was present [13]. In some of these patients a cursory bronchoscopic examination following topical anesthesia was adequate to permit localization and to direct therapy. However, initial bronchoscopy to identify gross mucosal lesions often was inadequate. Precise endoscopic localization must be accomplished if early treatment is to be offered these patients with roentgenographically occult lung cancer. A procedure has been developed by the Cooperative Lung Cancer Detection Task Force of the National Cancer Institute to localize the source of exfoliated cancer cells in these patients with normal findings on chest roentgenograms [ 131. However, the long time necessary for this detailed examination, often in excess of 2 hours, makes procedures that involve topical anesthesia unsatisfactory. In addition, repeated bronchoscopic examinations are often necessary, for which the patient usually prefers general anesthesia. The delivery and maintenance of safe endotracheal anesthesia while the airway is variously compromised by an assortment of rigid and fiberoptic instruments present a challenge to both the anesthesiologist and the endoscopist. Furthermore, the patients at risk for bronchogenic carcinoma are in an age group
From the Mayo Clinic and Mayo Foundation, Rochester, Minn. Accepted for publication Oct. 14, 1974. Supported in part by Research Contract CB-22000 from the National Institutes of Health, U.S. Public Health Service. Address reprint requests to Dr. Perry, Mayo Clinic, Rochester, Minn. 55901.
248
T H E ANNALS OF THORACIC SURGERY
Anesthesia for Prolonged Bronchoscopy that shares increased danger from coronary heart disease, chronic obstructive pulmonary disease, and other problems of aging. The purpose of this paper is to describe our methods of general anesthesia and the results obtained with these techniques.
Methods A description of the endoscopic procedure is necessary for understanding our anesthetic technique. This procedure can be divided into two phases. The first involves brief use of the open rigid bronchoscope, during which washings are obtained selectively from the left and right sides of the bronchial tree. The second is prolonged fiberoptic bronchoscopy involving videoscopic and photographic documentations, specimen collection by multiple brushings, and biopsy specimen collection from selective random sites. The rigid ventilating bronchoscope (ACMI, 8 mm by 40 cm) has no lateral vents in the distal end and employs an inflatable rubber cuff to provide an airtight seal in the bronchus or trachea. The bronchofiberscope (Olympus BF-5B, 5.5 mm) is inserted through a plastic endotracheal tube through a special closed T-adapter. Our present anesthetic technique has been developed to provide adequate oxygenation and ventilation as well as adequate anesthesia and relaxation. After several minutes of oxygenation, anesthesia is induced with thiopental and continued with halothane or enflurane in oxygen by mask for 10 to 15 minutes; nitrous oxide is not used at this time. Direct laryngoscopy is then performed with the aid of succinylcholine,and the vocal cords and trachea are sprayed with 4.0 ml of 4% lidocaine. Relaxation is maintained with the use of either 0.2% succinylcholine infusion or pancuronium bromide. After application of the topical anesthetic, the endoscopist inserts the open rigid bronchoscope into the trachea and the lungs are ventilated for 1 to 2 minutes. The bronchoscope is then inserted into the left main bronchus, the cuff is inflated, ventilation is stopped, and washings are obtained during a 1%- to 2-minute period. The cuff is deflated, the bronchoscope is moved back into the trachea, and ventilation is resumed for several minutes. Then the bronchoscope is repositioned in the right main bronchus and the cuff is inflated for selective washing on that side. The rigid bronchoscope is subsequently removed, and the patient is reintubated with a 10 mm ID plastic endotracheal tube. Fifty percent nitrous oxide is added to the anesthetic mixture, and ventilation is controlled for the duration of the procedure. Arterial blood gases are measured periodically to assess the effectiveness of ventilation. The patient is monitored continuously with a precordial stethoscope and an electrocardiographic oscilloscope. At the conclusion of the procedure, anesthesia is discontinued and the patient is allowed to awaken. The muscle relaxants are not reversed, and the endotracheal tube is left in for continued assisted or controlled ventilation. The F I O ~ and ventilation are adjusted as indicated by blood gas measurements, and the patient is extubated when he has recovered sufficiently from the effects of the procedure.
VOL. 19, NO. 3, MARCH, 1975
249
PERRY AND SANDERSON
Results This procedure has been performed 29 times on 22 different patients. Of the 22 patients, 17 were examined once, 3 were examined twice, and 2 were examined three times. All of the patients were men. The average age was 62 years(range 46 to 77), and the average duration of the procedure was 130 minutes (range 45 to 195). Halothane was used as the primary anesthetic in 9 patients, enflurane in 14, Innovar in 2, and thiopental in 4. Relaxation was maintained with succinylcholine in 19 cases and with pancuronium bromide in 8; 2 patients did not receive relaxants. There was 1 intraoperative complication: severe, persistent multifocal ventricular extrasystoles in a patient with known heart disease. Eight of the patients had significant bronchospasm in the recovery ward; 3 required therapy with intravenously administered aminophylline. In 19 of the 22 patients the primary malignancy was localized and treated. Seventeen had bronchogenic carcinoma of the squamous cell type, 1 had carcinoma at the base of the tongue, and 1 had carcinoma of the right vocal cord. The lesions in the latter 2 patients were identified by suspension laryngoscopy done in conjunction with the bronchoscopic examination. Of the 17 patients with lung cancer who were treated, 16 had operative resection and 1 had radiation therapy for a lesion in the carina and distal trachea. Of those undergoing resection, 14 had stage I squamous cell carcinoma and 2 had stage 111, according to the Staging Classification of the American Joint Committee on Cancer Staging and End Results Reporting. Both patients with upper airway lesions were treated: 1 (with the vocal cord lesion) was treated by cautery excision of the lesion and the other (with the lesion at the base of the tongue) by radiation therapy. Of the 3 untreated patients, 2 had lateralization accomplished on the basis of differential washings, but definitive treatment awaits more precise localization of the lesion by repeated bronchoscopy. The remaining patient had squamous cell metaplasia with marked atypia on initial sputum examinations, but all subsequent samples of washings and brushings showed mild to moderate atypia only. We regard this patient as not having frank lung cancer at the present time.
Comment Bronchoscopic examination is a vital part of the diagnostic and preoperative assessment of patients with bronchogenic carcinoma. Direct access to the tracheobronchial tree permits inspection, collection of secretions, and sampling by means of brush, curette, and forceps biopsy. To accomplish this with minimal hazard and discomfort to the patient, various techniques for topical and general anesthesia have been employed [ l , 111. Although adequacy of ventilation during bronchoscopy performed under topical anesthesia has rarely been a problem, such is not true with general anesthetic techniques. The problem of adequate ventilation and oxygenation has been appreciable, resulting in various methods and approaches [ 3 , 5 , 6 , 8 , 12, 141. These have generally involved a technique of light general anesthesia with intravenous muscle relaxants and controlled ventilation through a ventilating bronchoscope, a small endotracheal tube, or, more recently, some variant of the positive-pressure injector (Venturi) system. The 250
THE ANNALS OF THORACIC SURGERY
Anesthesia for Prolonged Bronchoscopy
recent development of fiberoptic bronchoscopes and their widespread employment have resulted in a resurgence of topical anesthetic techniques, with and without intravenous sedation, and the administration of general anesthesia with controlled ventilation through an endotracheal tube that is also used as a conduit for the bronchofiberscope [2, 4,151. The relatively brief time required for most examinations has made all these methods acceptable and applicable. The anesthetic requirements for a prolonged and complicated bronchoscopic procedure include those common to other peroral endoscopic techniques plus several that are peculiar to this procedure. The initial period of bronchial washing entails the problem of one lung at a time being alternately flooded with physiological solutions and aspirated while the other lung is totally bypassed by the bronchoscope. N o ventilation is possible during the washing of each lung, but we have been able to handle this satisfactorily by using apneic oxygenation. The usual attention to adequate ventilation requires more vigilance because of the demands of the procedure and the restriction of the air passage by the bronchoscope as well as by the endotracheal tube. It has been established that an endotracheal tube of 8.5 mm ID is the smallest through which the fiberoptic bronchoscope can be passed without unduly raising the resistance to air flow 19, 101. This is well illustrated in the Figure, which shows the resistance to increasing air flows through various sizes of endotracheal tubes with the 6 mm bronchofiberscope inserted. Even with a tube of 10 mm ID, which we use routinely, the resistance to air flow is higher than through a tube of 8.0 mm ID without the bronchofiberscope inserted. In addition, the presence of the bronchoscope in the various subdivisions of the bronchial tree further obstructs ventilation. The anesthesiologist must be continually aware that normal ventilatory support often is inadequate, and the Paco, should be checked periodically. Blood gas data (as summarized from 7 patients) reveal that Pa% values remain high after the two periods of apneic oxygenation, whereas Paco2 values are moderately increased, as would be expected (Table). Thereafter, during Air flow through various endotracheal tubes with or without insertion of bronchofiberscope 6 mm in diameter.
70
t
/
emm tube
/
9.omm tube 9.5 mm tube
emm tube without bronchofiberscope .2
I .4
.6
I
4.0
4:s
2:o
.8
Flow, L/s VOL. 19, NO. 3, MARCH, 1975
25 1
n
En
s
-I
8
78 76 59 74 57 65 77
37 41 39 39 38 34 40
Pa,.,,,
7.40
7.46 7.42 7.36 7.40 7.32 7.43 7.40
pH
'In millimeters of mercury. 'Fk,, = 0.40. 3Fki, = 0.33.
Mean 69.4 38.3
3 4 5 6 7
2
1
Patient No. Pao,
Patient Awake (Fk),= 0.21) pH 7.28 7.30 7.20 7.36 7.33 7.38 7.31 7.31
Pa,,,, 57 55 60 40 34 38 49 47.6
346 427 1362 359 467 1363 445
33 1
Pao,
After Bronchial Washings (Fk,, = 0.97)
251
174 239 79 156 268 92 249
Pao,
45.6
45 55 56 46 38 37 42
Pa, O1
Fiberscopy of 30 Minutes (Fq), =0.50)
7.33
7.35 7.29 7.22 7.30 7.37 7.42 7.33
pH
171
91 193 23 1 90 230
222
139
Pa,,,
7.35
7.35 7.34 7.32 7.36 7.36 7.42 7.30
45 44 44 40 36 33 51 41.9
pH
Pa,,,,
Fiberscopy of 60 Minutes (Fk), = 0.50)
107
98 63 106 82 120 112 171
Pao,
7.27
7.24 7.26 7.16 7.33 7.19 7.42 7.29
63 62 68 45 55 39 50 54.6
pH Pa,.,,,
Recovery Room (Fk,, = 0.40)
ARTERIAL BLOOD GAS DATA' ON 7 PATIENTS UNDERGOING PROLONGED BRONCHOSCOPY
Anesthesia for Prolonged Bronchoscopy fiberoptic bronchoscopy, oxygenation is also well maintained, but ventilation may tend to be somewhat inadequate. Halothane and enflurane are used as our main anesthetic agents because of their rapid action, nonflammability, and lack of bronchial irritation. Methoxyflurane has not been used because of the length of the induction procedure and because it does not supply the fairly deep anesthesia that is required. Isoflurane, when available, may be undesirable if there is bronchospasm, which has been reported to occur occasionally with its use.* Currently we prefer pancuronium bromide for relaxation because it seems to give a smoother anesthetic state than does intermittent-drip succinylcholine. Many patients experience bronchospasm in the recovery room. In some this is significant, with resulting respiratory acidosis; in a few it is severe enough to warrant bronchodilator therapy in addition to ventilatory support. Bronchospasm is enough of a problem that we leave the patient intubated and on a mechanical ventilator in the postanesthesia recovery room until he can safely care for himself (usually 1 to 3 hours).
References 1. Adriani, J. Anesthesia for endoscopy. Ann Otol Rhinol Laryngol 78:1129, 1969. 2. Barson, P. K., Scott, M. L., Martin, J. T., and Ochsner, J. L. Flexible fiberoptic bronchoscopy using general anesthesia: An improved technic. Anesth Analg (Cleve) 52:619, 1973. 3. Benson, D. W. A survey of general anesthesia for endoscopy. Ann Otol Rhinol Lalyngol 78:459, 1969. 4. Britton, R. M., and Nelson, K. G. Iniproper oxygenation during bronchofiberscopy. Anesthesiology 40:87, 1974. 5. Carden, E. Positive-pressure ventilation during anesthesia for bronchoscopy: A laboratory evaluation of two recent advances. Anesth Analg (Cleve) 52:402, 1973. 6. Foldes, F. F., and Maisel, W. Neuroleptanalgesia for peroral endoscopy. Arch Otolalyngol 91:280, 1970. 7. Fontana, R. S., Sanderson, D. R., Miller, W. E., Woolner, L. B., Taylor, W. F., and Uhlenhopp, M. A. The Mayo Lung Project: Preliminary report of “early cancer detection” phase. Cancer 30:1373, 1972. 8. Ciesecke, A. H.,Jr., Gerbershagen, H. U., Dortman, C., and Lee, D. Comparison of the ventilating and injection bronchoscopes. Anesthesiology 38:298, 1973. 9. Grossman, E., and Jacobi, A. M. Minimal optimal endotracheal tube size for fiberoptic bronchoscopy. Anesth Analg (Cleve) 53:475, 1974. 10. Perry, L. B. Discussion. In P. R. Raj, J. Forestner, T. D. Watson, R. E. Morris, and M. T.Jenkins, Technics for fiberoptic laryngoscopy in anesthesia. Anesth Analg (Cleve) 53:708, 1974. 1 1. Proctor, D. F. Anesthesia for peroral endoscopy and bronchography. Anesthesiology 29: 1025, 1968. 12. Sanders, R. D. Two ventilating attachments for bronchoscopes. Del Med J 39:170, 1967. 13. Sanderson, D. R., Fontana, R. S., Woolner, L. B., Bernatz, P. E., and Payne, W. S. Bronchoscopic localization of radiographically occult lung cancer. Chest 65:608, 1974. 14. Smith, F. R., Kundahl, P. C., and Fouty, R. The safety of general anesthesia for bronchoscopy demonstrated by a study of arterial and venous oxygen saturation levels. D k Chest 51:53, 1967. 15. Tahir, A. H. General anesthesia for bronchofiberscopy. Anesthesiology 37:564, 1972. *D. R. Krabill, personal communication, 1974.
VOL. 19, NO. 3, MARCH, 1975
253
