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Carbon dioxide insufflation for more comfortable colonoscopy
0016-5107/84/3002-0068$02.00 GASTROINTESTINAL ENDOSCOPY Copyright © 1984 by the American Society for Gastrointestinal Endoscopy
Carbon dioxide insufflation for more comfortable colonoscopy Abelel Moniem J. Hussein, DM(Cairo), MRCP(UK) Clive I. Bartram, MB, FRCP, MRCP Christopher B. Williams, BM, FRCP London, England
Forty patients examined with the use of carbon dioxide insufflation during fiberoptic colonoscopy showed no significant residual gas on plain radiographs taken 30 minutes after the procedure. By contrast, 19 of 20 patients examined with air insufflation showed excessive distension of large and/or small intestine. The rapid absorption of carbon dioxide may be a safety factor in a few patients and adds to the the comfort of the procedure in many others by virtually eliminating overdistension afterwards. It also makes it technically possible to perform a barium enema immediately after colonoscopy.
Colonoscopy has become a relatively quick and easy procedure due to the introduction of new and more maneuverable colonoscopes and better understanding of colonoscopic techniques. Attention can now be focused on trying to make the procedure comfortable and safe for the patient. Colonoscopes are at present designed primarily for air insufflation, but there have been several reports about the dangers and hazards of air-pressure induced colon injuries such as serosal tears and benign pneumoperitoneum. I - 8 In addition, there have been reports of explosive complications of polypectomy through the rigid sigmoidoscope9 and recently during colonoscopic polypectomy lO-11 due to the presence of explosive gas concentrations. 12 • 13 Although there have been studies suggesting that the risk of explosive gas concentrations is theoretical and removed by adequate bowel preparation, 14.15 manufactu~ers have incorporated a channel for carbon dioxide insufflation in order to minimize the danger of explosion during electrosurgery. We have been impressed by the number of patients complaining of discomfort due to air-distention for an hour or more after colonoscopy, compared to the absence of such symptoms when carbon dioxide insufflation is used. Carbon dioxide is known to be rapidly absorbed from the colon and promptly eliminated From St. Mark's Hospital, London, England. Reprint requests: Dr. C. B. Williams, St. Mark's Hospital, City Road, London, England ECI.
68
through the lungs; in cats, carbon dioxide is eliminated from the lungs a thousand times faster than it is absorbed from the alimentary tract. 16,17 Studies in humans show that because of this very rapid elimination, there is no hazard from carbon dioxide insufflation during colonoscopy, even in patients with chronic lung disease. 18 We decided to compare the elimination of carbon dioxide or air insufflated during colonoscopy by means of plain abdominal radiographs taken at an interval after the procedure. MATERIALS AND METHODS Patients
Sixty patients having postpolypectomy follow-up colonoscopy were chosen for the study, excluding women in their reproductive years. All patients gave informed consent. Forty were allocated to receive carbon dioxide insufflation during examination, the air supply being switched off and any water washing made manually with the syringe attachment. Total colonoscopy was performed and sufficient insufflation was used for careful inspection of the bowel during insertion and withdrawal of the instrument. In all patients the colon was deflated as far as possible by aspiration in the rectum before removing the colonoscope at the end of the procedure. All patients were examined by the same endoscopist to avoid any interpersonal variation of technique. GASTROINTESTINAL ENDOSCOPY
Radiological assessment
A plain radiograph of the abdomen was taken immediately before and 30 min after the procedure; some patients had an additional film taken immediately after removal of the colonoscope. A fixed tube-film distance was used to ensure comparability of the films. The radiographs were coded and presented to a single expert gastrointestinal radiologist who was unaware of the gas used during colonoscopy. The radiographs were graded according to visible colonic gas shadows between 0 (no gas or normally expected volumes), + (minimal excess), ++ (moderate excess) and +++ (considerable excess). An approximate quantitation of the volumes of gas present was made by measuring individual segments of gas-filled colon and converting the measurements according to the formula: (II diam 2 X length)/4. This rough measurement suggested the volume equivalent of the radiologist's grading 0 as <100 ml, ++ as >300 ml, and +++ as >1000 ml of gas. RESULTS
Several patients in both the carbon dioxide and air insufflation groups complained of distension immediately following the procedure in spite of the attempts to avoid this. Figure lA shows the distended appearance of one such patient after colonoscopy using carbon dioxide with gas in the small intestine. Figure IB demonstrates graphically the rapid absorption of gas 30 min later in the same patient, the patient being unaware of passage of any flatus. It was considered desirable to limit the number of radiographs taken; thus, after several successive patients had been shown to undergo this sequence of inflation and deflation, the rest of the study was limited to "before and after" films only. The summary of results in the 60 patients studied are shown in Table 1 which demonstrates the very marked difference in the amount of colonic gas present at 30 min after colonoscopy. Air insufflation patients had moderate or considerable excess of gas at that time compared to 19 of 20 no gas or minimal excess in the carbon dioxide patients. DISCUSSION
Most endoscopists are aware that overdistension during colonoscopy is undesirable, uncomfortable, even dangerous. Only the few who see and question their patients in the hours after colonoscopy (when any sedation will have worn off) realize that a significant number of patients have discomfort many hours afterwards. Some patients complain that the aftermath of the procedure is worse than the examination itself. We are aware of patients too distended to dress normally 12 or more hours later, presumably indicatVOLUME 30, NO.2, 1984
Figure 1. Plain abdominal radiographs of patient insufflated with carbon dioxide during colonoscopy. A, 3 min after procedure (note small intestinal as well as colonic gas); graded +++ (see text). B, 30 min after procedure showing disappearance of gas; graded + (see text).
69
Table 1. Comparison of estimated residual gas volumes on plain abdominal radiographs 30 min after colonoscopy with the use of either carbon dioxide insufflation or air insufflation. Residual gas on abdominal x-ray"
CO 2 insufflation (40 patients) Air insufflation (20 patients)
0
+
20
20 1
++
+++
7
12
"Grading of radiographs: 0 (no gas or normally expected volumes), + (minimal excess: <100 ml), ++ (moderate excess: >300 ml), and +++ (considerable excess: >1000 ml).
ing small-intestinal as well as colonic distension. Although it is often suggested that excess air can be aspirated as the instrument is progressively withdrawn, any serious attempt to do this must make it difficult to examine all areas properly and accurately. Even for fiber sigmoidoscopy it could be advantageous to use carbon dioxide routinely, thus ensuring that the patient has no aftereffects and that electrosurgical procedures are safe when limited bowel preparation increases the likelihood of formed stool and explosive gas concentrations in the proximal colon. 19 We have put our demonstration of the rapid absorption of colonic carbon dioxide to good clinical use since we have found it possible in high risk patients to follow colonoscopy within 20 to 30 min by aircontrast barium enema for the purpose of a doubly accurate procedure. The barium enema gives information on colonic configuration and demonstrates any potential colonoscopic blind spots. Double bowel preparation at 2 to 3 days' interval would be needed if barium enema was to be performed before colonoscopy, whereas by reversing the order the endoscopist can ensure that any fecal residue is aspirated and radiological accuracy enhanced. We have performed over 250 colonoscopy-barium enema combined examinations with excellent technical results20; the procedures were well tolerated by the patients due to the sedation used for the endoscopy. The same sequence could be used to perform unsedated fiber sigmoidoscopy with carbon dioxide immediately before doublecontrast barium enema as a screening procedure. Rogers 18 has shown that there is no contraindication to carbon dioxide insufflation, and our observations suggest that it has significant advantages and should be more often employed for patient comfort and for
70
efficiency as well as for complete safety. As a result of this experience, we use carbon dioxide insufflation for colonoscopy in any patient in whom abdominal pain or bloating is a presenting feature, usually because of diverticular disease or the irritable bowel syndromeboth common conditions. We also use it in patients with strictures or inflammatory bowel disease so as to avoid prolonged distension.
REFERENCES 1. Degradi AE, Norris ME, Weingarten ZG. Delayed "blowout" perforation of sigmoid following diagnostic colonoscopy. Am J GastroenteroI1978;70:317-20. 2. Ecker MD, Godstein M, Holxter B. Benign pneumoperitoneum after fibreoptic colonoscopy: a prospective study of 100 patients. Gastroenterology 1977;73:226. 3. Lezak MB, Goldhamer M. Retroperitoneal emphysema after colonoscopy. Gastroenterology 1974;66:118. 4. Glouberman S, Craner GE, Oglenru RM. Radiographic survey for extraluminal air following gastrointestinal tract fiberendoscopy. Gastrointest Endosc 1976;22:165-7. 5. Gordon MJ. Retroperitoneal emphysema from colonoscopy of the distal limb of a Hartmann colostomy. Gastrointest Endosc 1975;22:101-2. 6. Kozarek RA, Earnest DL, Silverstein ME, Smith RG. Airpressure induced colon injury during diagnostic colonoscopy. Gastroenterology 1980;78:7-14. 7. Meyers MA, Ghahremani GG. Complications of fibreoptic endoscopy: colonoscopy. Radiology 1975;115:301-7. 8. Razzak lA, Millan J, Schuster MM. Pneumatic ileal perforation: an unusual complication of colonoscopy. Gastroenterology 1976;70:268-71. 9. Carter HG. Explosion in colon during electro dessication of polyps. Am J Surg 1952;84:514-6. 10. Bigard MA, Gaucher P, Lasalle C. Fatal colonic explosion during colonoscopic polypectomy. Gastroenterology 1979;77:1307-9. 11. Raillat A, Saint-Julien J de, Abgrall J. Explosion colique au cours d'une electrocoagulation endoscopique apres preparation au mannitol. Gastroenterol Clin 1982;6:301-2. 12. Fruhmorgen P, Joachim G. Gas chromatographic. Analyses of intestinal gas to clarify the question of inert gas insufflation in electrosurgical endoscopy. Endoscopy 1976;8:133-5. 13. La Brooy SJ, Avgerinos A, Fendick CL, Williams CB, Misiewicz JJ. Potentially explosive colonic concentrations of hydrogen after bowel preparation with mannitol. Lancet 1981;1:634-6. 14. Ragins H, Shinya H, Wolff WI. The explosive potential of colonic gas during colonoscopic electrosurgical polypectomy. Surg Gynecol Obstet 1974;138:554-6. 15. Bond JH, Levitt MD. Factors influencing the concentration of combustible gases in the colon during colonoscopy. Gastroenterology 1975;68:1445---8. 16. Saltzman HA, Sieker HO. Intestinal response to changing gaseous environments: normobaric and hyperbaric observations. Ann NY Acad Aci 1968;150:11. 17. Forster RE. Physiological basis of gas exchange. Ann NY Acad Sci 1968;150:11. 18. Rogers BHG. The safety of carbon dioxide insufflation during colonoscopic electrosurgical polypectomy. Gastrointest Endosc 1974;20:115. 19. Bond JH, Levitt MD. Colonic gas explosion-Is a fire extinguisher necessary? Gastroenterology 1979;77:1349-50. 20. Williams CB, Macrae FA, Bartram CI. A prospective study of diagnostic methods in adenoma follow-up. Endoscopy 1982;14:74-8.
GASTROINTESTINAL ENDOSCOPY
Carbon dioxide insufflation for more comfortable colonoscopy Abelel Moniem J. Hussein, DM(Cairo), MRCP(UK) Clive I. Bartram, MB, FRCP, MRCP Christopher B. Williams, BM, FRCP London, England
Forty patients examined with the use of carbon dioxide insufflation during fiberoptic colonoscopy showed no significant residual gas on plain radiographs taken 30 minutes after the procedure. By contrast, 19 of 20 patients examined with air insufflation showed excessive distension of large and/or small intestine. The rapid absorption of carbon dioxide may be a safety factor in a few patients and adds to the the comfort of the procedure in many others by virtually eliminating overdistension afterwards. It also makes it technically possible to perform a barium enema immediately after colonoscopy.
Colonoscopy has become a relatively quick and easy procedure due to the introduction of new and more maneuverable colonoscopes and better understanding of colonoscopic techniques. Attention can now be focused on trying to make the procedure comfortable and safe for the patient. Colonoscopes are at present designed primarily for air insufflation, but there have been several reports about the dangers and hazards of air-pressure induced colon injuries such as serosal tears and benign pneumoperitoneum. I - 8 In addition, there have been reports of explosive complications of polypectomy through the rigid sigmoidoscope9 and recently during colonoscopic polypectomy lO-11 due to the presence of explosive gas concentrations. 12 • 13 Although there have been studies suggesting that the risk of explosive gas concentrations is theoretical and removed by adequate bowel preparation, 14.15 manufactu~ers have incorporated a channel for carbon dioxide insufflation in order to minimize the danger of explosion during electrosurgery. We have been impressed by the number of patients complaining of discomfort due to air-distention for an hour or more after colonoscopy, compared to the absence of such symptoms when carbon dioxide insufflation is used. Carbon dioxide is known to be rapidly absorbed from the colon and promptly eliminated From St. Mark's Hospital, London, England. Reprint requests: Dr. C. B. Williams, St. Mark's Hospital, City Road, London, England ECI.
68
through the lungs; in cats, carbon dioxide is eliminated from the lungs a thousand times faster than it is absorbed from the alimentary tract. 16,17 Studies in humans show that because of this very rapid elimination, there is no hazard from carbon dioxide insufflation during colonoscopy, even in patients with chronic lung disease. 18 We decided to compare the elimination of carbon dioxide or air insufflated during colonoscopy by means of plain abdominal radiographs taken at an interval after the procedure. MATERIALS AND METHODS Patients
Sixty patients having postpolypectomy follow-up colonoscopy were chosen for the study, excluding women in their reproductive years. All patients gave informed consent. Forty were allocated to receive carbon dioxide insufflation during examination, the air supply being switched off and any water washing made manually with the syringe attachment. Total colonoscopy was performed and sufficient insufflation was used for careful inspection of the bowel during insertion and withdrawal of the instrument. In all patients the colon was deflated as far as possible by aspiration in the rectum before removing the colonoscope at the end of the procedure. All patients were examined by the same endoscopist to avoid any interpersonal variation of technique. GASTROINTESTINAL ENDOSCOPY
Radiological assessment
A plain radiograph of the abdomen was taken immediately before and 30 min after the procedure; some patients had an additional film taken immediately after removal of the colonoscope. A fixed tube-film distance was used to ensure comparability of the films. The radiographs were coded and presented to a single expert gastrointestinal radiologist who was unaware of the gas used during colonoscopy. The radiographs were graded according to visible colonic gas shadows between 0 (no gas or normally expected volumes), + (minimal excess), ++ (moderate excess) and +++ (considerable excess). An approximate quantitation of the volumes of gas present was made by measuring individual segments of gas-filled colon and converting the measurements according to the formula: (II diam 2 X length)/4. This rough measurement suggested the volume equivalent of the radiologist's grading 0 as <100 ml, ++ as >300 ml, and +++ as >1000 ml of gas. RESULTS
Several patients in both the carbon dioxide and air insufflation groups complained of distension immediately following the procedure in spite of the attempts to avoid this. Figure lA shows the distended appearance of one such patient after colonoscopy using carbon dioxide with gas in the small intestine. Figure IB demonstrates graphically the rapid absorption of gas 30 min later in the same patient, the patient being unaware of passage of any flatus. It was considered desirable to limit the number of radiographs taken; thus, after several successive patients had been shown to undergo this sequence of inflation and deflation, the rest of the study was limited to "before and after" films only. The summary of results in the 60 patients studied are shown in Table 1 which demonstrates the very marked difference in the amount of colonic gas present at 30 min after colonoscopy. Air insufflation patients had moderate or considerable excess of gas at that time compared to 19 of 20 no gas or minimal excess in the carbon dioxide patients. DISCUSSION
Most endoscopists are aware that overdistension during colonoscopy is undesirable, uncomfortable, even dangerous. Only the few who see and question their patients in the hours after colonoscopy (when any sedation will have worn off) realize that a significant number of patients have discomfort many hours afterwards. Some patients complain that the aftermath of the procedure is worse than the examination itself. We are aware of patients too distended to dress normally 12 or more hours later, presumably indicatVOLUME 30, NO.2, 1984
Figure 1. Plain abdominal radiographs of patient insufflated with carbon dioxide during colonoscopy. A, 3 min after procedure (note small intestinal as well as colonic gas); graded +++ (see text). B, 30 min after procedure showing disappearance of gas; graded + (see text).
69
Table 1. Comparison of estimated residual gas volumes on plain abdominal radiographs 30 min after colonoscopy with the use of either carbon dioxide insufflation or air insufflation. Residual gas on abdominal x-ray"
CO 2 insufflation (40 patients) Air insufflation (20 patients)
0
+
20
20 1
++
+++
7
12
"Grading of radiographs: 0 (no gas or normally expected volumes), + (minimal excess: <100 ml), ++ (moderate excess: >300 ml), and +++ (considerable excess: >1000 ml).
ing small-intestinal as well as colonic distension. Although it is often suggested that excess air can be aspirated as the instrument is progressively withdrawn, any serious attempt to do this must make it difficult to examine all areas properly and accurately. Even for fiber sigmoidoscopy it could be advantageous to use carbon dioxide routinely, thus ensuring that the patient has no aftereffects and that electrosurgical procedures are safe when limited bowel preparation increases the likelihood of formed stool and explosive gas concentrations in the proximal colon. 19 We have put our demonstration of the rapid absorption of colonic carbon dioxide to good clinical use since we have found it possible in high risk patients to follow colonoscopy within 20 to 30 min by aircontrast barium enema for the purpose of a doubly accurate procedure. The barium enema gives information on colonic configuration and demonstrates any potential colonoscopic blind spots. Double bowel preparation at 2 to 3 days' interval would be needed if barium enema was to be performed before colonoscopy, whereas by reversing the order the endoscopist can ensure that any fecal residue is aspirated and radiological accuracy enhanced. We have performed over 250 colonoscopy-barium enema combined examinations with excellent technical results20; the procedures were well tolerated by the patients due to the sedation used for the endoscopy. The same sequence could be used to perform unsedated fiber sigmoidoscopy with carbon dioxide immediately before doublecontrast barium enema as a screening procedure. Rogers 18 has shown that there is no contraindication to carbon dioxide insufflation, and our observations suggest that it has significant advantages and should be more often employed for patient comfort and for
70
efficiency as well as for complete safety. As a result of this experience, we use carbon dioxide insufflation for colonoscopy in any patient in whom abdominal pain or bloating is a presenting feature, usually because of diverticular disease or the irritable bowel syndromeboth common conditions. We also use it in patients with strictures or inflammatory bowel disease so as to avoid prolonged distension.
REFERENCES 1. Degradi AE, Norris ME, Weingarten ZG. Delayed "blowout" perforation of sigmoid following diagnostic colonoscopy. Am J GastroenteroI1978;70:317-20. 2. Ecker MD, Godstein M, Holxter B. Benign pneumoperitoneum after fibreoptic colonoscopy: a prospective study of 100 patients. Gastroenterology 1977;73:226. 3. Lezak MB, Goldhamer M. Retroperitoneal emphysema after colonoscopy. Gastroenterology 1974;66:118. 4. Glouberman S, Craner GE, Oglenru RM. Radiographic survey for extraluminal air following gastrointestinal tract fiberendoscopy. Gastrointest Endosc 1976;22:165-7. 5. Gordon MJ. Retroperitoneal emphysema from colonoscopy of the distal limb of a Hartmann colostomy. Gastrointest Endosc 1975;22:101-2. 6. Kozarek RA, Earnest DL, Silverstein ME, Smith RG. Airpressure induced colon injury during diagnostic colonoscopy. Gastroenterology 1980;78:7-14. 7. Meyers MA, Ghahremani GG. Complications of fibreoptic endoscopy: colonoscopy. Radiology 1975;115:301-7. 8. Razzak lA, Millan J, Schuster MM. Pneumatic ileal perforation: an unusual complication of colonoscopy. Gastroenterology 1976;70:268-71. 9. Carter HG. Explosion in colon during electro dessication of polyps. Am J Surg 1952;84:514-6. 10. Bigard MA, Gaucher P, Lasalle C. Fatal colonic explosion during colonoscopic polypectomy. Gastroenterology 1979;77:1307-9. 11. Raillat A, Saint-Julien J de, Abgrall J. Explosion colique au cours d'une electrocoagulation endoscopique apres preparation au mannitol. Gastroenterol Clin 1982;6:301-2. 12. Fruhmorgen P, Joachim G. Gas chromatographic. Analyses of intestinal gas to clarify the question of inert gas insufflation in electrosurgical endoscopy. Endoscopy 1976;8:133-5. 13. La Brooy SJ, Avgerinos A, Fendick CL, Williams CB, Misiewicz JJ. Potentially explosive colonic concentrations of hydrogen after bowel preparation with mannitol. Lancet 1981;1:634-6. 14. Ragins H, Shinya H, Wolff WI. The explosive potential of colonic gas during colonoscopic electrosurgical polypectomy. Surg Gynecol Obstet 1974;138:554-6. 15. Bond JH, Levitt MD. Factors influencing the concentration of combustible gases in the colon during colonoscopy. Gastroenterology 1975;68:1445---8. 16. Saltzman HA, Sieker HO. Intestinal response to changing gaseous environments: normobaric and hyperbaric observations. Ann NY Acad Aci 1968;150:11. 17. Forster RE. Physiological basis of gas exchange. Ann NY Acad Sci 1968;150:11. 18. Rogers BHG. The safety of carbon dioxide insufflation during colonoscopic electrosurgical polypectomy. Gastrointest Endosc 1974;20:115. 19. Bond JH, Levitt MD. Colonic gas explosion-Is a fire extinguisher necessary? Gastroenterology 1979;77:1349-50. 20. Williams CB, Macrae FA, Bartram CI. A prospective study of diagnostic methods in adenoma follow-up. Endoscopy 1982;14:74-8.
GASTROINTESTINAL ENDOSCOPY