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ANAESTHESIA FOR A PATIENT UNDERGOING TRANSTHORACIC ENDOSCOPIC VAGOTOMY
British Journal of Anaesthesia 1992; 68: 318-320
CASE REPORT
ANAESTHESIA FOR A PATIENT UNDERGOING TRANSTHORACIC ENDOSCOPIC VAGOTOMY P. T. CHUI, T. GIN AND S. C. S. CHUNG
SUMMARY
KEY WORDS Anaesthesia' thoracic, one-lung thoracic endoscopic vagotomy.
ventilation. Surgery: trans-
Endoscopic surgery minimizes trauma in gaining access to surgical sites. Benefits include minimal postoperative pain, reduction in postoperative complications, avoidance of large surgical scars, shorter hospital stay and earlier resumption of normal activities for the patient [1]. In addition to gynaecological operations, endoscopic abdominal surgery includes appendicectomy and cholecystectomy [2, 3]. There is increasing acceptance of the technique and more widespread applications are likely to follow. This is the first report of anaesthesia for a patient who underwent vagotomy using the transthoracic endoscopic technique.
CD
I
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Liqno.
16 140
'
a, g
'
wWV
vvv
v
V
v v v v v v vvv w
V
° r ioo| K
~X
Q_ <
Sa Ol (%) CASE REPORT
A 58-yr-old man (70 kg) had undergone gastrectomy 4 yr previously for bleeding gastric ulcer. He continued to have repeated episodes of gastrointestinal bleeding which required admission to hospital and multiple blood transfusions, despite treatment with ranitidine and omeprazole. Upper gastrointestinal endoscopy revealed an anastomotic ulcer. Revision vagotomy was considered necessary and the patient consented to have the procedure performed with the transthoracic endoscopic technique. His medical history was otherwise unremarkable and physical examination revealed no abnormal findings. Preoperative investigations revealed microcytic hypochromic anaemia with a haemoglobin concentration of 10.7 g dl"1. Renal function tests, chest x-ray and
• OLV
180 n
-co,
*A
80 60J
AA
""AAA
4097 100 98 98 98 98 98 97 98 97 98 20-I \ 4.6 5.0 4.6 4.5 4.5 4.5 4.6 4.5 4.6 4.6 0 • r 60 180 120 Time (min)
FIG. 1. Summary of the intraoperative course during transthoracic endoscopic vagotomy. OLV = one-lung ventilation; Ligno. = lignocaine 100 mg i.v.; Sa^ = arterial oxygen saturation: F/CC. = end-tidal carbon dioxide concentration; SAP, DAP «= systolic, diastolic arterial pressure; HR = heart rate.
P. T . CHUI, M.B., B.S., F.F.A.R.A.C.S., T . GlN, M.B., CH.B-, F.C.ANAES., F.F.A.R. A.c.s. (Department of Anaesthesia and Intensive Care); S. C. S. CHUNG, M.D., F.R.C.S.(ED.), M.R.C.P.(U.K.) (De-
partment of Surgery); Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, N.T., Hong Kong. Accepted for Publication: September 11, 1991. Correspondence to P.T.C.
Downloaded from http://bja.oxfordjournals.org/ at York University Libraries on July 26, 2015
We describe the anaesthetic management of a patient who underwent transthoracic endoscopic vagotomy. One-lung ventilation was necessary to provide adequate surgical access. Potential intraoperative problems involved arterial oxygen saturation during one-lung ventilation, unequal intrathoracic pressures causing mediastinal displacement and inadvertent myocardial injury by surgical instruments and diathermy. The management of these problems and the benefits of endoscopic surgery to the patient are discussed.
ECG were normal. Diazepam 10 mg was given orally 1 h before operation. Anaesthesia was induced with thiopentone 300 mg, fentanyl 100 ug and suxamethonium 100 mg i.v. The trachea was intubated with a left-sided Robertshaw double-lumen endobronchial tube. The right lung was selectively ventilated. Anaesthesia was maintained with 0.5-1.5% isoflurane in 100% oxygen and incremental doses of atracurium and fentanyl. A nasogastric tube was inserted. Monitoring included ECG, non-invasive arterial pressure, ventilation pressure, oxygen analyser, pulse oximetry, end-tidal carbon dioxide concentration and nasopharyngeal temperature. Surgery was performed with the patient in the right lateral position. The first trocar and cannula was inserted at the eighth intercostal space in the posterior axillary line for attachment of the endocamera. Three accessory trocars and cannulae were inserted under endoscopic vision. The diaphragm and the left lung were retracted with endoscopic retractors and the oesophagus and vagi mobilized in
ANAESTHESIA FOR TRANSTHORACIC ENDOSCOPIC VAGOTOMY
DISCUSSION
Technological advances in micro-chip video cameras, high resolution monitors and optical systems with xenon light source, rod lens and fluid light cables have produced considerable progress in endoscopic surgery [4]. The operative field may be displayed on a video monitor, allowing two-handed dissection and performance of more complicated procedures. Laparoscopic cholecystectomy has gained widespread acceptance [5]. The problems of anaesthesia for endoscopic abdominal procedures have been studied extensively with laparoscopic gynaecological procedures [6, 7]. These are associated mostly with effects of tension pneumoperitoneum, carbon dioxide absorption, extraperitoneal instillation of carbon dioxide, venous gas embolism and unintentional injuries to intra-abdominal structures [8]. Transthoracic procedures performed usually with rigid thoracoscopes are limited to diagnostic and simple therapeutic procedures such as pleurodesis [9]. Anaesthetic techniques include regional anaesthesia and general anaesthesia with double-lumen endobronchial tubes allowing one-lung ventilation (OLV) [10]. Anaesthesia for complex endoscopic thoracic surgery poses additional problems. In the case report described here, video view of the operative field was restricted and surgical manipulation and dissection with endoscopic instruments were technically more demanding. The use of a double-lumen endobronchial tube was necessary to allow collapse of one lung to improve surgical access. The patient maintained satisfactory arterial oxygen saturation (Sa^) during OLV with 100% oxygen. Application of continuous positive airway pressure (CPAP) [11] and insufflation of the collapsed lung with oxygen [12] would have been used if necessary for improving SaOi. However, CPAP and, to a lesser extent, oxygen insufflation would also have caused partial expansion of the collapsed lung, hindering surgical access. Other methods of improving 5'aOi would include careful patient positioning, adequate neuromuscular block to minimize intrathoracic pressure, optimization of cardiac output to reduce
venous admixture, adjustment of tidal volumes and application of positive end-expiratory pressure to the ventilated lung [13, 14]. The use of low-dose dobutamine infusion also has been reported to be useful [15]. Surgery may have to be abandoned in patients who cannot maintain an adequate Sa^ without application of CPAP or oxygen insufflation to the collapsed lung. This should be discussed with the surgeon and patient before operation. Procedures performed with a rigid thoracoscope often require pressurized air to create an artificial pneumothorax to improve surgical exposure. This was shown to be tolerated well, even in spontaneously breathing patients [16, 17]. However, unequal pressures within the two thoracic cavities may cause mediastinal displacement with serious haemodynamic effects. Carbon dioxide insufflators designed to create a pneumoperitoneum may deliver gas at pressures greater than 40 mm Hg [18]. These should not be used for producing a pneumothorax. Within an enclosed space, suction used to clear blood, smoke and irrigation fluid from the surgical field may cause large negative intrathoracic pressures with the same risk of mediastinal displacement. Nitrous oxide diffusing into the enclosed cavity also could cause pressure changes. These problems are avoided by opening the taps of the endoscope cannulae to air, allowing the intrathoracic pressure to equilibrate with atmosphere at all times. Collapse of the lung under its own elastic recoil provided adequate surgical access in the present case. With the proximity of the heart to the surgical site, accidental physical irritation of the heart was inevitable, especially as the video view was restricted and only two-dimensional. Ventricular ectopic beats precipitated in our patient were benign, and did not cause haemodynamic problems. However, the possibility of precipitating malignant ventricular arrhythmias needs to be considered [19]. It is also important to avoid factors that enhance myocardial arrhythmias, such as the use of halothane and hypoor hypercapnia. Unintentional application of surgical diathermy to the liver surface is common during laparoscopic cholecystectomy and this does not produce clinical consequences. Inadvertent application of diathermy to the heart, however, produces areas of myocardial damage that may become foci of arrhythmias. Diathermy to the epicardial blood vessels may provoke vasospasm and thrombosis, leading to myocardial ischaemia. The major disadvantage of the procedure was the prolonged duration of surgery. This may be reduced with greater experience in the technique, as occurred with laparoscopic cholecystectomy [20]. In retrospect, an intra-arterial cannula would have been useful for monitoring haemodynamic changes and blood sampling for arterial blood-gas analysis. The benefits of endoscopic surgery were illustrated well in this patient. In contrast with truncal vagotomy performed through an upper abdominal incision, our patient's postoperative recovery was rapid and devoid of problems such as intestinal ileus and wound infection. Postoperative pain was minimal. The patient enjoyed early resumption of normal activities, with little risk of deep vein thrombosis and
Downloaded from http://bja.oxfordjournals.org/ at York University Libraries on July 26, 2015
the groove between the heart and the descending aorta. The patient developed ventricular ectopic beats when the heart was probed accidentally by the pointed surgical instruments. This was controlled temporarily with lignocaine 100 mg i.v. and the surgeons were informed of the problem. The operation was performed with the taps of the endoscope cannulae open to atmosphere, allowing air to move freely in and out of the left thoracic cavity. The duration of surgery was approximately 3.5 h, and blood loss was less than 100 ml. The intraoperative course was uneventful overall (fig. 1). A 32-French gauge chest drain was inserted at the end of the procedure. The patient required one dose of parenteral pethidine for analgesia in the evening after surgery. He resumed normal oral diet and was ambulatory on the first day after operation. The chest drain was removed on the second day and the patient was discharged the next day.
319
BRITISH JOURNAL OF ANAESTHESIA
320
pulmonary embolism. Hospital stay was short and medical costs less than those associated with standard surgery.
11. 12.
13. 14. 15.
16. 17. 18. 19. 20.
Downloaded from http://bja.oxfordjournals.org/ at York University Libraries on July 26, 2015
REFERENCES 1. Cuschieri A, Berci G, McSherry CK. Laparoscopic cholecystectomy. American Journal of Surgery 1990; 159: 273. 2. Semm K. Endoscopic appendicectomy. Endoscopy 1983; 15: 59-64. 3. Dobois F, Icard P, Berthelot G, Levard H. Coelioscopic cholccystectomy: preliminary repon of 36 cases. Annals of Surgery 1990; 211: 60-62. 4. Cuschieri A. Laparoscopic cholecystectomy. British Journal of Hospital Medicine 1991; 45: 65. 5. Gadacz TR, Talamini MA, Lillemoe KD, Yeo CJ. Laparoscopic cholecystectomy. Surgical Clinics of North America 1990; 70: 1249-1262. 6. Alexander GD, Noe FE, Brown EM. Anesthesia for laparoscopy. Anesthesia and Analgesia 1969; 48: 14—18. 7. Ohlgisser M, Sorokin Y, Heifetz M. Gynecologic laparoscopy: a review article. Obstetrical and Gynecological Survey 1985; 40: 385-396. 8. Marco AP, Yeo CJ, Rock P. Anesthesia for a patient undergoing laparoscopic cholecystectomy. Anesthesiology 1990; 73: 1268-1270. 9. Page RD, Jeffrey RR, Donnelly RJ. Thoracoscopy: a review of 121 consecutive surgical procedures. Annals of Thoracic Surgery 1989; 48: 66-68. 10. Benumof JL, Alfery DD. Anesthesia for thoracic surgery. In:
Miller RD, ed. Anesthesia, 2nd Edn. New York: Churchill Livingstone, 1986; 1371-1462. Capan LM, Turndorf H, Patel C, Ramanathan S, Acinapura A, Chalon J. Optimization of arterial oxygenation during onelung anesthesia. Anesthesia and Analgesia 1980; 59: 847-851. Rees DI, Wansbrough SR. One-lung anesthesia: percent shunt and arterial oxygen saturation during continuous insufflation of oxygen to the nonventilated lung. Anesthesia and Analgesia 1982; 61: 507-512. Cohen E, Thys DM, Eisenkraft JB, Kaplan JA. PEEP during one-lung anesthesia improves oxygenation in patients with low arterial Pa^. Anesthesia and Analgesia 1985; 64: 201. Katz JA, Laveme RG, Fairley HB, Thomas AN. Pulmonary oxygen exchange during endobronchial anesthesia: effect of tidal volume and PEEP. Anesthesiology 1982; 56: 164-171. Nomto Y, Kawamura M. Pulmonary gas exchange effects by rntroglycerin, dopamine and dobutamine during one-lung ventilation in man. Canadian Journal of Anaesthesia 1989;36: 273-277. Oldenburg FA, Newhouse MT. Thoracoscopy: a safe, accurate diagnostic procedure using the rigid thoracoscope and local anesthesia. Chest 1979; 75: 45-50. Faurschou P, Madsen F, Viskum K. Thoracoscopy: influence of the procedure on some respiratory and cardiac values. Thorax 1983; 38: 341-343. Instruction manual of Olympus PNE-C and PNE-N Automatic Gas Insufflator for Laparoscopy. Olympus Optical System Limited, Japan. Atlee JL. Perioperative Cardiac Dysrhythmias: Mechanisms, Recognition, Management. Chicago: Year Book Medical Publishers, Inc., 1985. Nottle PN, Wale RJ, Johnson WR. Percutaneous cholecystectomy : thefirstfifty.Australian and New Zealand Journal of Surgery 1991; 61: 254-260.
CASE REPORT
ANAESTHESIA FOR A PATIENT UNDERGOING TRANSTHORACIC ENDOSCOPIC VAGOTOMY P. T. CHUI, T. GIN AND S. C. S. CHUNG
SUMMARY
KEY WORDS Anaesthesia' thoracic, one-lung thoracic endoscopic vagotomy.
ventilation. Surgery: trans-
Endoscopic surgery minimizes trauma in gaining access to surgical sites. Benefits include minimal postoperative pain, reduction in postoperative complications, avoidance of large surgical scars, shorter hospital stay and earlier resumption of normal activities for the patient [1]. In addition to gynaecological operations, endoscopic abdominal surgery includes appendicectomy and cholecystectomy [2, 3]. There is increasing acceptance of the technique and more widespread applications are likely to follow. This is the first report of anaesthesia for a patient who underwent vagotomy using the transthoracic endoscopic technique.
CD
I
\ \ <:' E
Liqno.
16 140
'
a, g
'
wWV
vvv
v
V
v v v v v v vvv w
V
° r ioo| K
~X
Q_ <
Sa Ol (%) CASE REPORT
A 58-yr-old man (70 kg) had undergone gastrectomy 4 yr previously for bleeding gastric ulcer. He continued to have repeated episodes of gastrointestinal bleeding which required admission to hospital and multiple blood transfusions, despite treatment with ranitidine and omeprazole. Upper gastrointestinal endoscopy revealed an anastomotic ulcer. Revision vagotomy was considered necessary and the patient consented to have the procedure performed with the transthoracic endoscopic technique. His medical history was otherwise unremarkable and physical examination revealed no abnormal findings. Preoperative investigations revealed microcytic hypochromic anaemia with a haemoglobin concentration of 10.7 g dl"1. Renal function tests, chest x-ray and
• OLV
180 n
-co,
*A
80 60J
AA
""AAA
4097 100 98 98 98 98 98 97 98 97 98 20-I \ 4.6 5.0 4.6 4.5 4.5 4.5 4.6 4.5 4.6 4.6 0 • r 60 180 120 Time (min)
FIG. 1. Summary of the intraoperative course during transthoracic endoscopic vagotomy. OLV = one-lung ventilation; Ligno. = lignocaine 100 mg i.v.; Sa^ = arterial oxygen saturation: F/CC. = end-tidal carbon dioxide concentration; SAP, DAP «= systolic, diastolic arterial pressure; HR = heart rate.
P. T . CHUI, M.B., B.S., F.F.A.R.A.C.S., T . GlN, M.B., CH.B-, F.C.ANAES., F.F.A.R. A.c.s. (Department of Anaesthesia and Intensive Care); S. C. S. CHUNG, M.D., F.R.C.S.(ED.), M.R.C.P.(U.K.) (De-
partment of Surgery); Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, N.T., Hong Kong. Accepted for Publication: September 11, 1991. Correspondence to P.T.C.
Downloaded from http://bja.oxfordjournals.org/ at York University Libraries on July 26, 2015
We describe the anaesthetic management of a patient who underwent transthoracic endoscopic vagotomy. One-lung ventilation was necessary to provide adequate surgical access. Potential intraoperative problems involved arterial oxygen saturation during one-lung ventilation, unequal intrathoracic pressures causing mediastinal displacement and inadvertent myocardial injury by surgical instruments and diathermy. The management of these problems and the benefits of endoscopic surgery to the patient are discussed.
ECG were normal. Diazepam 10 mg was given orally 1 h before operation. Anaesthesia was induced with thiopentone 300 mg, fentanyl 100 ug and suxamethonium 100 mg i.v. The trachea was intubated with a left-sided Robertshaw double-lumen endobronchial tube. The right lung was selectively ventilated. Anaesthesia was maintained with 0.5-1.5% isoflurane in 100% oxygen and incremental doses of atracurium and fentanyl. A nasogastric tube was inserted. Monitoring included ECG, non-invasive arterial pressure, ventilation pressure, oxygen analyser, pulse oximetry, end-tidal carbon dioxide concentration and nasopharyngeal temperature. Surgery was performed with the patient in the right lateral position. The first trocar and cannula was inserted at the eighth intercostal space in the posterior axillary line for attachment of the endocamera. Three accessory trocars and cannulae were inserted under endoscopic vision. The diaphragm and the left lung were retracted with endoscopic retractors and the oesophagus and vagi mobilized in
ANAESTHESIA FOR TRANSTHORACIC ENDOSCOPIC VAGOTOMY
DISCUSSION
Technological advances in micro-chip video cameras, high resolution monitors and optical systems with xenon light source, rod lens and fluid light cables have produced considerable progress in endoscopic surgery [4]. The operative field may be displayed on a video monitor, allowing two-handed dissection and performance of more complicated procedures. Laparoscopic cholecystectomy has gained widespread acceptance [5]. The problems of anaesthesia for endoscopic abdominal procedures have been studied extensively with laparoscopic gynaecological procedures [6, 7]. These are associated mostly with effects of tension pneumoperitoneum, carbon dioxide absorption, extraperitoneal instillation of carbon dioxide, venous gas embolism and unintentional injuries to intra-abdominal structures [8]. Transthoracic procedures performed usually with rigid thoracoscopes are limited to diagnostic and simple therapeutic procedures such as pleurodesis [9]. Anaesthetic techniques include regional anaesthesia and general anaesthesia with double-lumen endobronchial tubes allowing one-lung ventilation (OLV) [10]. Anaesthesia for complex endoscopic thoracic surgery poses additional problems. In the case report described here, video view of the operative field was restricted and surgical manipulation and dissection with endoscopic instruments were technically more demanding. The use of a double-lumen endobronchial tube was necessary to allow collapse of one lung to improve surgical access. The patient maintained satisfactory arterial oxygen saturation (Sa^) during OLV with 100% oxygen. Application of continuous positive airway pressure (CPAP) [11] and insufflation of the collapsed lung with oxygen [12] would have been used if necessary for improving SaOi. However, CPAP and, to a lesser extent, oxygen insufflation would also have caused partial expansion of the collapsed lung, hindering surgical access. Other methods of improving 5'aOi would include careful patient positioning, adequate neuromuscular block to minimize intrathoracic pressure, optimization of cardiac output to reduce
venous admixture, adjustment of tidal volumes and application of positive end-expiratory pressure to the ventilated lung [13, 14]. The use of low-dose dobutamine infusion also has been reported to be useful [15]. Surgery may have to be abandoned in patients who cannot maintain an adequate Sa^ without application of CPAP or oxygen insufflation to the collapsed lung. This should be discussed with the surgeon and patient before operation. Procedures performed with a rigid thoracoscope often require pressurized air to create an artificial pneumothorax to improve surgical exposure. This was shown to be tolerated well, even in spontaneously breathing patients [16, 17]. However, unequal pressures within the two thoracic cavities may cause mediastinal displacement with serious haemodynamic effects. Carbon dioxide insufflators designed to create a pneumoperitoneum may deliver gas at pressures greater than 40 mm Hg [18]. These should not be used for producing a pneumothorax. Within an enclosed space, suction used to clear blood, smoke and irrigation fluid from the surgical field may cause large negative intrathoracic pressures with the same risk of mediastinal displacement. Nitrous oxide diffusing into the enclosed cavity also could cause pressure changes. These problems are avoided by opening the taps of the endoscope cannulae to air, allowing the intrathoracic pressure to equilibrate with atmosphere at all times. Collapse of the lung under its own elastic recoil provided adequate surgical access in the present case. With the proximity of the heart to the surgical site, accidental physical irritation of the heart was inevitable, especially as the video view was restricted and only two-dimensional. Ventricular ectopic beats precipitated in our patient were benign, and did not cause haemodynamic problems. However, the possibility of precipitating malignant ventricular arrhythmias needs to be considered [19]. It is also important to avoid factors that enhance myocardial arrhythmias, such as the use of halothane and hypoor hypercapnia. Unintentional application of surgical diathermy to the liver surface is common during laparoscopic cholecystectomy and this does not produce clinical consequences. Inadvertent application of diathermy to the heart, however, produces areas of myocardial damage that may become foci of arrhythmias. Diathermy to the epicardial blood vessels may provoke vasospasm and thrombosis, leading to myocardial ischaemia. The major disadvantage of the procedure was the prolonged duration of surgery. This may be reduced with greater experience in the technique, as occurred with laparoscopic cholecystectomy [20]. In retrospect, an intra-arterial cannula would have been useful for monitoring haemodynamic changes and blood sampling for arterial blood-gas analysis. The benefits of endoscopic surgery were illustrated well in this patient. In contrast with truncal vagotomy performed through an upper abdominal incision, our patient's postoperative recovery was rapid and devoid of problems such as intestinal ileus and wound infection. Postoperative pain was minimal. The patient enjoyed early resumption of normal activities, with little risk of deep vein thrombosis and
Downloaded from http://bja.oxfordjournals.org/ at York University Libraries on July 26, 2015
the groove between the heart and the descending aorta. The patient developed ventricular ectopic beats when the heart was probed accidentally by the pointed surgical instruments. This was controlled temporarily with lignocaine 100 mg i.v. and the surgeons were informed of the problem. The operation was performed with the taps of the endoscope cannulae open to atmosphere, allowing air to move freely in and out of the left thoracic cavity. The duration of surgery was approximately 3.5 h, and blood loss was less than 100 ml. The intraoperative course was uneventful overall (fig. 1). A 32-French gauge chest drain was inserted at the end of the procedure. The patient required one dose of parenteral pethidine for analgesia in the evening after surgery. He resumed normal oral diet and was ambulatory on the first day after operation. The chest drain was removed on the second day and the patient was discharged the next day.
319
BRITISH JOURNAL OF ANAESTHESIA
320
pulmonary embolism. Hospital stay was short and medical costs less than those associated with standard surgery.
11. 12.
13. 14. 15.
16. 17. 18. 19. 20.
Downloaded from http://bja.oxfordjournals.org/ at York University Libraries on July 26, 2015
REFERENCES 1. Cuschieri A, Berci G, McSherry CK. Laparoscopic cholecystectomy. American Journal of Surgery 1990; 159: 273. 2. Semm K. Endoscopic appendicectomy. Endoscopy 1983; 15: 59-64. 3. Dobois F, Icard P, Berthelot G, Levard H. Coelioscopic cholccystectomy: preliminary repon of 36 cases. Annals of Surgery 1990; 211: 60-62. 4. Cuschieri A. Laparoscopic cholecystectomy. British Journal of Hospital Medicine 1991; 45: 65. 5. Gadacz TR, Talamini MA, Lillemoe KD, Yeo CJ. Laparoscopic cholecystectomy. Surgical Clinics of North America 1990; 70: 1249-1262. 6. Alexander GD, Noe FE, Brown EM. Anesthesia for laparoscopy. Anesthesia and Analgesia 1969; 48: 14—18. 7. Ohlgisser M, Sorokin Y, Heifetz M. Gynecologic laparoscopy: a review article. Obstetrical and Gynecological Survey 1985; 40: 385-396. 8. Marco AP, Yeo CJ, Rock P. Anesthesia for a patient undergoing laparoscopic cholecystectomy. Anesthesiology 1990; 73: 1268-1270. 9. Page RD, Jeffrey RR, Donnelly RJ. Thoracoscopy: a review of 121 consecutive surgical procedures. Annals of Thoracic Surgery 1989; 48: 66-68. 10. Benumof JL, Alfery DD. Anesthesia for thoracic surgery. In:
Miller RD, ed. Anesthesia, 2nd Edn. New York: Churchill Livingstone, 1986; 1371-1462. Capan LM, Turndorf H, Patel C, Ramanathan S, Acinapura A, Chalon J. Optimization of arterial oxygenation during onelung anesthesia. Anesthesia and Analgesia 1980; 59: 847-851. Rees DI, Wansbrough SR. One-lung anesthesia: percent shunt and arterial oxygen saturation during continuous insufflation of oxygen to the nonventilated lung. Anesthesia and Analgesia 1982; 61: 507-512. Cohen E, Thys DM, Eisenkraft JB, Kaplan JA. PEEP during one-lung anesthesia improves oxygenation in patients with low arterial Pa^. Anesthesia and Analgesia 1985; 64: 201. Katz JA, Laveme RG, Fairley HB, Thomas AN. Pulmonary oxygen exchange during endobronchial anesthesia: effect of tidal volume and PEEP. Anesthesiology 1982; 56: 164-171. Nomto Y, Kawamura M. Pulmonary gas exchange effects by rntroglycerin, dopamine and dobutamine during one-lung ventilation in man. Canadian Journal of Anaesthesia 1989;36: 273-277. Oldenburg FA, Newhouse MT. Thoracoscopy: a safe, accurate diagnostic procedure using the rigid thoracoscope and local anesthesia. Chest 1979; 75: 45-50. Faurschou P, Madsen F, Viskum K. Thoracoscopy: influence of the procedure on some respiratory and cardiac values. Thorax 1983; 38: 341-343. Instruction manual of Olympus PNE-C and PNE-N Automatic Gas Insufflator for Laparoscopy. Olympus Optical System Limited, Japan. Atlee JL. Perioperative Cardiac Dysrhythmias: Mechanisms, Recognition, Management. Chicago: Year Book Medical Publishers, Inc., 1985. Nottle PN, Wale RJ, Johnson WR. Percutaneous cholecystectomy : thefirstfifty.Australian and New Zealand Journal of Surgery 1991; 61: 254-260.