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Intestinal Intubation: Techniques, Safeguards, Complications
Intestinal Intubation Techniques, Safeguards, Complications DAVID H. WAGNER, M.D., F.A.C.S. *
INDICATIONS AND USES
ALTHOUGH methods of intestinal intubation have been known to the medical profession for many years it was Dr. Owen Wangensteen who, in the early 1930's, greatly increased its popularity and use by careful analysis of the pathologic physiology in mechanical intestinal obstruction, and by the successful treatment of these changes with continuous suction to an indwelling tube. The intestinal tube to withdraw gases and liquids from the bowel has a great many uses in modern surgery. It is probably the most effective method of treatment of adynamic ileus secondary to extra-intestinal trauma, peritonitis, cholecystitis, spinal injuries, trauma of abdominal operations or pneumonia. In incomplete, simple, mechanical obstruction it may serve as the definitive treatment and may obviate the necessity for an operation. In complete, simple, intestinal obstruction and in strangulating obstruction it is an invaluable aid preoperatively, by helping to reverse the disastrous pathological physiology of distention. It makes it possible to safely delay operation until the patient is in proper fluid and electrolyte balance. At the operation it simplifies locating the point of obstruction, facilitates the ease and speed of operation and prevents the trauma of manipulation to the distended bowel. Postoperatively it withdraws gas and flui~ accumulating secondary to the trauma of operation and facilitates the return of normal peristaltic activity of the bowel. In any operation on the colon, such as resection of the right or left half, abdominoperineal resection, colostomy or by-passing operation, it is invaluable in preventing any large amounts of gas from entering the colon. It thus acts as a prophylaxis against postoperative distention and subsequent complications. In very large incisional hernias continuous suction to an indwelling intestinal tube reduces the abdominal distention sufficiently to make * Assistant Professor of Surgery, Chicago Medical School,· Associate Attending Surgeon, Michael Reese Hospital. 151
152
David H. Wagner
the operation easier, and to prevent the disruption of the fascia in the early postoperative period. In some conditions the only proper method of treatment is surgical, and suction with the intestinal tube becomes only an adjunct to the operation. The most obvious one of these conditions is strangulation of the bowel in the course of a mechanical obstruction. This is primarily a surgical condition demanding operation without delay. If intestinal intubation is used it must be auxiliary to the operation. Mesenteric thrombosis with gangrene of the bowel can be treated successfully only by early operative intervention, and intestinal suction may be used only to help relieve the associated bowel distention. Obstructing lesions of the large bowel producing great distention proximal to the obstructing mechanism are frequently closed loop obstructions because of the action of the ileocecal valve. The intraluminal pressure in this closed loop rises so high as to lead to perforation of the thinned-out cecal wall and demands that an early cecostomy or colostomy be performed. Here, too, the intestinal suction must be an auxiliary method of treatment. The most important and most common use of the intestinal tube for decompression is in mechanical obstruction of the small bowel. As pointed out by Wangensteen, gas accumulating in the bowel in this condition comes from three sources: (1) swallowed air, which represents 70 per cent of the total and is largely nitrogen, (2) putrefaction and fermentation, and (3) diffusion of gas into the bowel from the blood stream. When an obstruction of the bowel occurs a train of events takes place proximal to the obstructing mechanism which begins with the accumulation of gas and distention. An increase in intraluminal tension occurs which results in a decrease in absorption and a secondary accumulation of constantly forming intestinal secretions. At the same time anoxia, due to increased pressure upon the venous system in the bowel wall, results in capillary permeability and the passage of fluid from the vascular bed into the bowel wall tissues. As edema of the bowel wall increases, some of this fluid passes into the lumen of the bowel. With increasing distention the bowel wall becomes thinner and thinner until" even without perforation, bacteria may migrate through it into the peritoneal cavity. If the obstructing mechanism is unrelieved the progressive distention ultimately compromises the blood supply and necrosis with ulceration and perforation of the bowel wall occurs. Early intubation of a tube into the intestine in this condition will prevent the initial increase in intraluminal tension, by withdrawal of gases and liquids, and will prevent this disastrous train of events from occurring. Later in the disease process, decompression prevents the possibility of ulceration or perforation, and reduces the edema and intraluminal fluid and gas. If edema of the bowel wall is partly responsible for the obstructing mechanism, such as occurs with an adhesive
Intestinal Intubation
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band, then the withdrawal of fluid and gas results in a diminution of the edema and a possible release of the obstruction. The disadvantages of intestinal intubation are first that it is sometimes extremely difficult to pass the tube beyond the stomach. It may remain in the stomach in spite of every reasonable effort to get the tip into the duodenum. This usually occurs in patients who are most ill, such as in longstanding intestinal obstruction with greatly distended loops of small bowel, or in adynamic ileus with little or no peristaltic action. Second, the discomfort of having a tube in one's nose for a number days becomes extremely trying to the patient. TECHNIQUE AND PROCEDURE
Several different types of intestinal tubes are available. The MillerAbbott tube, introduced in 1934, is a double lumen, long rubber tube with an air-filled balloon attached around the distal few inches of the tube. One of the lumens is used for inflating and deflating the balloon, the other is used for suction of intestinal contents. The Cantor tube is a single lumen, long rubber tube with a bag containing mercury attached to and hanging from the distal tip of the tube. The leading point of this tube is the bag of mercury, which moves through the gastrointestinal tract somewhat easier than does the air-filled balloon. The Harris tube is a single lumen rubber tube with a mercury-filled balloon attached around the distal few inches of the tube. The single lumen has the advantage of using all the available cross-sectional area of the tube for purposes of suction. A further advantage of this tube over the Miller-Abbott tube is its mercury-filled balloon. A fourth type of intestinal tube is the Kaslow tube. This is fashioned on the principle of the Harris tube, with a single lumen and a mercuryfilled balloon attached around the distal few inches. However, the tube is made of plastic material instead of rubber. The good features of this tube are its (1) single lumen, (2) mercury-filled balloon and (3) plastic material. Through the plastic tube one can easily see the contents of the gastrointestinal tract which is being· withdrawn, and can quickly and easily determine in what portion of the tract the tip of the tube lies. Prior to introducing an intestinal tube the application of a 2 per cent Pontocaine solution to the nasal mucosa diminishes the sensation and eases the introduction of the balloon. The head of the patient should be extended. The tube should be lubricated. The balloon is twisted to reduce its size and to force the mercury proximally. It is then introduced through the larger nasal opening. As soon as the balloon passes into the nasopharynx the patient is given a drink of water, and then while he is swallowing, the tube is gently pushed forward. This allows the tube to be swallowed and prevents its passage into the trachea. The tube then easily passes down the esophagus with a little assistance
David H . Wagner
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from the person introducing it. When about 18 inches (40 cm.) of the tube has been swallowed it will enter the stomach. At this point, one way of determining that the tube is in the stomach is to try to aspirate the stomach contents with a bulb syringe attached to the proximal end of the tube, and to continue to push the tube downward until stomach contents are able to be withdrawn. At this time it is important to introduce only so much additional tubing as will allow the distal tip to enter the duodenum. This additional length of tubing should be 6 to 12 inches beyond the 18 inches, or a total of 24 to 30 inches. When 24 to 30 inches of the tube have been introduced it is attached to the nose with adhesive tape. Too much tubing allowed into the stomach at this time results in its curling up, and forces the tip of the tube away from the pylorus. Relaxation of the pyloric sphincter by the inhalation of amyl nitrite or the injection of atropine may be helpful. The patient is then turned on his right side and remains in this position until the tip of the tube has passed into the duodenum. This can best be determined by watching the material that is being aspirated. As long as the tip of the tube is in the stomach the aspirated material is whitish-green or green and contains many flecks of solid material. When the tip of the tube passes into the duodenum the aspirated material, which can be most easily observed through a plastic tube, is a perfectly clear, light, brownish yellow bile and does not contain any flecks of solid material. This is positive identification of the fact that the tube is in the duodenum and is very useful information. If any doubt exists as to the exact position of the tip of the tube an x-ray should be taken to determine its location. When the tube is well into the second portion of the duodenum, the tape is removed from the tube at the nose, and the patient allowed to swallow the tube at the rate of about 1 inch per hour. At this time he no longer needs to remain on his right side and can move into any desired position. From this point on the tube tip moves easily, by peristaltic action, into the third portion of the duodenum and on into the jejunum and ileum. As the tube descends into the small bowel the aspirated material becomes thicker, and dark greenish brown in color, and contains more solid matter. If allowed to continue the tip of the tube will pass down to the point of obstruction. If no point of obstruction exists in the small bowel the tip of the tube will pass through the ileocecal valve into the colon and has on occasions appeared at the anus. When the tube has descended into the intestine as far as is necessary it should again be fixed to the nose with adhesive tape so that no further descent will take place. SAFEGUARDS
It is imperative to remember that in mechanical intestinal obstruction the intestinal decompression, by an indwelling tube, must be con-
Intestinal Intubation
155
sidered only an adjunct to surgery. While it is true that the favorable course of the illness following intestinal intubation may result in relieving the patient of his obstruction without operation, to consider intestinal intubation alone as definitive treatment will result in many catastrophes .. Constant attention to the dynamic course of the disease process is therefore essential and surgical intervention must be instituted, if necessary, at the appropriate time. In general, if intestinal distention increases or fails to recede, even though the tube has been functioning well for 24 hours, it is likely that the obstruction is unrelieved and that operation should be performed. Once an intestinal tube is effectively withdrawing gas and fluid from the distended intestine in a case of simple mechanical obstruction, the pain will disappear, the abdominal distention will diminish and the patient will look and feel much improved. It is at this point that a surgeon must be especially vigilant because he may be easily lulled into a false sense of security while the obstruction continues on unabated to more serious consequences. Frequent x-rays showing the intestinal pattern will determine whether or not gas is passing beyond the point of the suspected obstruction. If gas is present in the large bowel, when prior to the intestinal aspiration there was no gas in the large bowel, one can presume that the edema is diminishing and that the obstruction is being relieved. The passage of flatus following intestinal aspiration, if a previous x-ray showed no gas in the large bowel, is equally significant and permits the continuation of conservative therapy. If, however, in spite of the diminution of pain, the reduction in abdominal distention and the apparent well-being of the patient, there is neither flatus nor x-ray evidence of the passage of gas distal to the point of obstruction, it must be assumed that the obstruction is persisting and that surgical intervention is imperative. Attention should be called to the fact that, during these x-ray studies, air introduced into the colon in the process of giving an enema will obscure the pattern of gas and make a decision much more difficult. This introduced air may be incorrectly interpreted as coming from above the obstruction, when in fact such is not the case. If an enema, therefore, is given after an x-ray of the bowel has been taken and therapy begun, every effort should be made to prevent the introduction of air into the colon. If, during the course of intestinal aspiration for mechanical obstruction tenderness of the abdomen occurs, a tender mass is palpable, there is an elevation in the temperature or a steady rise in the pulse rate, together with a leukocytosis, these are all evidences of strangulation of the bowel and demand that operation be performed without delay. The withdrawal of large quantities of fluid from the intestinal tract results in a great imbalance in electrolytes and in body fluids. It is essential to calculate the amount of fluid aspirated daily and to keep
David H. Wagner
156
the patient in proper fluid balance, by returning adequate quantities of fluid to the body by the intravenous route. Frequent electrolyte studies of the blood will guide the physician in keeping the patient in a proper electrolyte balance. ,··"Blockage of the lumen of the tube by solid material will prevent adequate suction of intestinal contents. The tube can be kept clear by irrigating it with small amounts of water. When the tip of the tube is in the stomach a small amount of water swallowed by the patient gives him an opportunity to moisten his throat and reduces the sense of thirst. Soon after swallowing the water, the suction will draw it back through the tube, indicating that the tube is clear. The negative pressure used to aspirate intestinal contents should not be so great as to "suck" the mucosa into the openings of the tube. For this reason an intermittent negative pressure may be more effective than a continuous negative pressure. This can be accomplished with an electrically controlled suction pump. Because of the many glass connections and vacuum bottles used in this procedure, it is necessary to check frequently in order to be certain that there is no leakage of air at any point. A small leak at any point will prevent the building up of negative pressure within the tube and thus nullify the usefulness of the apparatus. COMPLICATIONS
The most common complication of intestinal intubation, according to Chaffee, is a disturbance in the fluid and electrolyte balance induced by indiscriminate aspiration. Dehydration, hypochloremia and alkalosis may develop in the course of therapy. Although the other complications are not common, some which can occur are serious and distressing. Laryngeal obstruction is one of the most serious; a pressure necrosis of the anterior ~wall of the esophagus occurs near its attachment to the body of the cricoid cartilage. Perichondritis and ulceration of the mucous membrane of the adjacent cricoid cartilage follows, with consequent acute subglottic stenosis of the larynx. A tracheotomy then becomes necessary. Fatal hemorrhage from rupture of esophageal varices following prolonged contact of a tube with these varices has been reported. Other reported complications are rupture, ulceration or stricture of the esophagus, rupture of the stomach or small bowel, sinusitis, otitis media, knotting of the tube, inability to withdraw the tube and breakage of the mercury filled bag. On rare occasions it is difficult or impossible to withdraw the tube. This is particularly true if the tip of the tube has passed through the ileocecal valve. Should this occur patience will usually effect a successful outcome. Leaving the tube in place and attempting its removal an
Intestinal Intubation
157
hour or so later will frequently allow it to be dislodged and withdrawn. If one is still unable to withdraw it at this time continued forceful effort might result in tearing the intestine or its mesentery. It is, there-
fore, wiser to cut it off at the nose and to allow it to pass down through the intestine. The tube may remain in the intestine for many days before passing out through the rectum and anus. It has on occasion become twisted and caused an obstruction of the bowel necessitating surgical intervention. Occasionally the tip of the tube will appear at the anus while the proximal end still projects from the nose. In this case the proximal end should be cut off at the nose and the tube then withdrawn through the anus. Rupture of the mercury-filled bag in the intestine has failed to produce any serIOUS consequences. Chaffee suggests the following warnings to prevent complications: 1. Remove the tube in case of dyspnea, dysphagia, hoarseness or croupy cough. 2. The position of the tip of the tube should be changed daily. 3. The presence of esophageal varices is a contraindication to intestinal intubation. 4. Remove the tube as soon as its work is completed. 5. When the mercury bag has passed through the ileocecal junction, withdraw with extreme care under fluoroscopy, or cut off the tube at the nose and allow it to pass down the intestine. SUMMARY
In summary, intestinal intubation is an invaluable aid in the management of many surgical conditions of the bowel. However, because of the many possible pitfalls, its use requires an intelligent and vigilant attitude on the part of the physician. REFERENCES Berry, R. E. L.: Diagnosis and Treatment of Acute Intestinal Obstruction. J.A. M.A. 148: 347-355 (Feb. 2) 1952. Cantor, M. 0.: Intestinal Intubation. 1st Ed. Springfield, Ill., Charles C Thomas, 1949. Chaffee, J. S.: Complications of Gastrointestinal Intubation. Ann. Surg. 130: 113-123, 1949. Johnston, C. G.: Decompression in the Treatment of Intestinal Obstruction. Surg., Gynec. & Obst. 70: 365-369, 1940. Wangensteen, O. H.: Intestinal Obstructions. 2nd Ed. Springfield, Ill., Charles C Thomas, 1942. 25 E. Washington Street Chicago 2, Illinois
INDICATIONS AND USES
ALTHOUGH methods of intestinal intubation have been known to the medical profession for many years it was Dr. Owen Wangensteen who, in the early 1930's, greatly increased its popularity and use by careful analysis of the pathologic physiology in mechanical intestinal obstruction, and by the successful treatment of these changes with continuous suction to an indwelling tube. The intestinal tube to withdraw gases and liquids from the bowel has a great many uses in modern surgery. It is probably the most effective method of treatment of adynamic ileus secondary to extra-intestinal trauma, peritonitis, cholecystitis, spinal injuries, trauma of abdominal operations or pneumonia. In incomplete, simple, mechanical obstruction it may serve as the definitive treatment and may obviate the necessity for an operation. In complete, simple, intestinal obstruction and in strangulating obstruction it is an invaluable aid preoperatively, by helping to reverse the disastrous pathological physiology of distention. It makes it possible to safely delay operation until the patient is in proper fluid and electrolyte balance. At the operation it simplifies locating the point of obstruction, facilitates the ease and speed of operation and prevents the trauma of manipulation to the distended bowel. Postoperatively it withdraws gas and flui~ accumulating secondary to the trauma of operation and facilitates the return of normal peristaltic activity of the bowel. In any operation on the colon, such as resection of the right or left half, abdominoperineal resection, colostomy or by-passing operation, it is invaluable in preventing any large amounts of gas from entering the colon. It thus acts as a prophylaxis against postoperative distention and subsequent complications. In very large incisional hernias continuous suction to an indwelling intestinal tube reduces the abdominal distention sufficiently to make * Assistant Professor of Surgery, Chicago Medical School,· Associate Attending Surgeon, Michael Reese Hospital. 151
152
David H. Wagner
the operation easier, and to prevent the disruption of the fascia in the early postoperative period. In some conditions the only proper method of treatment is surgical, and suction with the intestinal tube becomes only an adjunct to the operation. The most obvious one of these conditions is strangulation of the bowel in the course of a mechanical obstruction. This is primarily a surgical condition demanding operation without delay. If intestinal intubation is used it must be auxiliary to the operation. Mesenteric thrombosis with gangrene of the bowel can be treated successfully only by early operative intervention, and intestinal suction may be used only to help relieve the associated bowel distention. Obstructing lesions of the large bowel producing great distention proximal to the obstructing mechanism are frequently closed loop obstructions because of the action of the ileocecal valve. The intraluminal pressure in this closed loop rises so high as to lead to perforation of the thinned-out cecal wall and demands that an early cecostomy or colostomy be performed. Here, too, the intestinal suction must be an auxiliary method of treatment. The most important and most common use of the intestinal tube for decompression is in mechanical obstruction of the small bowel. As pointed out by Wangensteen, gas accumulating in the bowel in this condition comes from three sources: (1) swallowed air, which represents 70 per cent of the total and is largely nitrogen, (2) putrefaction and fermentation, and (3) diffusion of gas into the bowel from the blood stream. When an obstruction of the bowel occurs a train of events takes place proximal to the obstructing mechanism which begins with the accumulation of gas and distention. An increase in intraluminal tension occurs which results in a decrease in absorption and a secondary accumulation of constantly forming intestinal secretions. At the same time anoxia, due to increased pressure upon the venous system in the bowel wall, results in capillary permeability and the passage of fluid from the vascular bed into the bowel wall tissues. As edema of the bowel wall increases, some of this fluid passes into the lumen of the bowel. With increasing distention the bowel wall becomes thinner and thinner until" even without perforation, bacteria may migrate through it into the peritoneal cavity. If the obstructing mechanism is unrelieved the progressive distention ultimately compromises the blood supply and necrosis with ulceration and perforation of the bowel wall occurs. Early intubation of a tube into the intestine in this condition will prevent the initial increase in intraluminal tension, by withdrawal of gases and liquids, and will prevent this disastrous train of events from occurring. Later in the disease process, decompression prevents the possibility of ulceration or perforation, and reduces the edema and intraluminal fluid and gas. If edema of the bowel wall is partly responsible for the obstructing mechanism, such as occurs with an adhesive
Intestinal Intubation
153
band, then the withdrawal of fluid and gas results in a diminution of the edema and a possible release of the obstruction. The disadvantages of intestinal intubation are first that it is sometimes extremely difficult to pass the tube beyond the stomach. It may remain in the stomach in spite of every reasonable effort to get the tip into the duodenum. This usually occurs in patients who are most ill, such as in longstanding intestinal obstruction with greatly distended loops of small bowel, or in adynamic ileus with little or no peristaltic action. Second, the discomfort of having a tube in one's nose for a number days becomes extremely trying to the patient. TECHNIQUE AND PROCEDURE
Several different types of intestinal tubes are available. The MillerAbbott tube, introduced in 1934, is a double lumen, long rubber tube with an air-filled balloon attached around the distal few inches of the tube. One of the lumens is used for inflating and deflating the balloon, the other is used for suction of intestinal contents. The Cantor tube is a single lumen, long rubber tube with a bag containing mercury attached to and hanging from the distal tip of the tube. The leading point of this tube is the bag of mercury, which moves through the gastrointestinal tract somewhat easier than does the air-filled balloon. The Harris tube is a single lumen rubber tube with a mercury-filled balloon attached around the distal few inches of the tube. The single lumen has the advantage of using all the available cross-sectional area of the tube for purposes of suction. A further advantage of this tube over the Miller-Abbott tube is its mercury-filled balloon. A fourth type of intestinal tube is the Kaslow tube. This is fashioned on the principle of the Harris tube, with a single lumen and a mercuryfilled balloon attached around the distal few inches. However, the tube is made of plastic material instead of rubber. The good features of this tube are its (1) single lumen, (2) mercury-filled balloon and (3) plastic material. Through the plastic tube one can easily see the contents of the gastrointestinal tract which is being· withdrawn, and can quickly and easily determine in what portion of the tract the tip of the tube lies. Prior to introducing an intestinal tube the application of a 2 per cent Pontocaine solution to the nasal mucosa diminishes the sensation and eases the introduction of the balloon. The head of the patient should be extended. The tube should be lubricated. The balloon is twisted to reduce its size and to force the mercury proximally. It is then introduced through the larger nasal opening. As soon as the balloon passes into the nasopharynx the patient is given a drink of water, and then while he is swallowing, the tube is gently pushed forward. This allows the tube to be swallowed and prevents its passage into the trachea. The tube then easily passes down the esophagus with a little assistance
David H . Wagner
154
from the person introducing it. When about 18 inches (40 cm.) of the tube has been swallowed it will enter the stomach. At this point, one way of determining that the tube is in the stomach is to try to aspirate the stomach contents with a bulb syringe attached to the proximal end of the tube, and to continue to push the tube downward until stomach contents are able to be withdrawn. At this time it is important to introduce only so much additional tubing as will allow the distal tip to enter the duodenum. This additional length of tubing should be 6 to 12 inches beyond the 18 inches, or a total of 24 to 30 inches. When 24 to 30 inches of the tube have been introduced it is attached to the nose with adhesive tape. Too much tubing allowed into the stomach at this time results in its curling up, and forces the tip of the tube away from the pylorus. Relaxation of the pyloric sphincter by the inhalation of amyl nitrite or the injection of atropine may be helpful. The patient is then turned on his right side and remains in this position until the tip of the tube has passed into the duodenum. This can best be determined by watching the material that is being aspirated. As long as the tip of the tube is in the stomach the aspirated material is whitish-green or green and contains many flecks of solid material. When the tip of the tube passes into the duodenum the aspirated material, which can be most easily observed through a plastic tube, is a perfectly clear, light, brownish yellow bile and does not contain any flecks of solid material. This is positive identification of the fact that the tube is in the duodenum and is very useful information. If any doubt exists as to the exact position of the tip of the tube an x-ray should be taken to determine its location. When the tube is well into the second portion of the duodenum, the tape is removed from the tube at the nose, and the patient allowed to swallow the tube at the rate of about 1 inch per hour. At this time he no longer needs to remain on his right side and can move into any desired position. From this point on the tube tip moves easily, by peristaltic action, into the third portion of the duodenum and on into the jejunum and ileum. As the tube descends into the small bowel the aspirated material becomes thicker, and dark greenish brown in color, and contains more solid matter. If allowed to continue the tip of the tube will pass down to the point of obstruction. If no point of obstruction exists in the small bowel the tip of the tube will pass through the ileocecal valve into the colon and has on occasions appeared at the anus. When the tube has descended into the intestine as far as is necessary it should again be fixed to the nose with adhesive tape so that no further descent will take place. SAFEGUARDS
It is imperative to remember that in mechanical intestinal obstruction the intestinal decompression, by an indwelling tube, must be con-
Intestinal Intubation
155
sidered only an adjunct to surgery. While it is true that the favorable course of the illness following intestinal intubation may result in relieving the patient of his obstruction without operation, to consider intestinal intubation alone as definitive treatment will result in many catastrophes .. Constant attention to the dynamic course of the disease process is therefore essential and surgical intervention must be instituted, if necessary, at the appropriate time. In general, if intestinal distention increases or fails to recede, even though the tube has been functioning well for 24 hours, it is likely that the obstruction is unrelieved and that operation should be performed. Once an intestinal tube is effectively withdrawing gas and fluid from the distended intestine in a case of simple mechanical obstruction, the pain will disappear, the abdominal distention will diminish and the patient will look and feel much improved. It is at this point that a surgeon must be especially vigilant because he may be easily lulled into a false sense of security while the obstruction continues on unabated to more serious consequences. Frequent x-rays showing the intestinal pattern will determine whether or not gas is passing beyond the point of the suspected obstruction. If gas is present in the large bowel, when prior to the intestinal aspiration there was no gas in the large bowel, one can presume that the edema is diminishing and that the obstruction is being relieved. The passage of flatus following intestinal aspiration, if a previous x-ray showed no gas in the large bowel, is equally significant and permits the continuation of conservative therapy. If, however, in spite of the diminution of pain, the reduction in abdominal distention and the apparent well-being of the patient, there is neither flatus nor x-ray evidence of the passage of gas distal to the point of obstruction, it must be assumed that the obstruction is persisting and that surgical intervention is imperative. Attention should be called to the fact that, during these x-ray studies, air introduced into the colon in the process of giving an enema will obscure the pattern of gas and make a decision much more difficult. This introduced air may be incorrectly interpreted as coming from above the obstruction, when in fact such is not the case. If an enema, therefore, is given after an x-ray of the bowel has been taken and therapy begun, every effort should be made to prevent the introduction of air into the colon. If, during the course of intestinal aspiration for mechanical obstruction tenderness of the abdomen occurs, a tender mass is palpable, there is an elevation in the temperature or a steady rise in the pulse rate, together with a leukocytosis, these are all evidences of strangulation of the bowel and demand that operation be performed without delay. The withdrawal of large quantities of fluid from the intestinal tract results in a great imbalance in electrolytes and in body fluids. It is essential to calculate the amount of fluid aspirated daily and to keep
David H. Wagner
156
the patient in proper fluid balance, by returning adequate quantities of fluid to the body by the intravenous route. Frequent electrolyte studies of the blood will guide the physician in keeping the patient in a proper electrolyte balance. ,··"Blockage of the lumen of the tube by solid material will prevent adequate suction of intestinal contents. The tube can be kept clear by irrigating it with small amounts of water. When the tip of the tube is in the stomach a small amount of water swallowed by the patient gives him an opportunity to moisten his throat and reduces the sense of thirst. Soon after swallowing the water, the suction will draw it back through the tube, indicating that the tube is clear. The negative pressure used to aspirate intestinal contents should not be so great as to "suck" the mucosa into the openings of the tube. For this reason an intermittent negative pressure may be more effective than a continuous negative pressure. This can be accomplished with an electrically controlled suction pump. Because of the many glass connections and vacuum bottles used in this procedure, it is necessary to check frequently in order to be certain that there is no leakage of air at any point. A small leak at any point will prevent the building up of negative pressure within the tube and thus nullify the usefulness of the apparatus. COMPLICATIONS
The most common complication of intestinal intubation, according to Chaffee, is a disturbance in the fluid and electrolyte balance induced by indiscriminate aspiration. Dehydration, hypochloremia and alkalosis may develop in the course of therapy. Although the other complications are not common, some which can occur are serious and distressing. Laryngeal obstruction is one of the most serious; a pressure necrosis of the anterior ~wall of the esophagus occurs near its attachment to the body of the cricoid cartilage. Perichondritis and ulceration of the mucous membrane of the adjacent cricoid cartilage follows, with consequent acute subglottic stenosis of the larynx. A tracheotomy then becomes necessary. Fatal hemorrhage from rupture of esophageal varices following prolonged contact of a tube with these varices has been reported. Other reported complications are rupture, ulceration or stricture of the esophagus, rupture of the stomach or small bowel, sinusitis, otitis media, knotting of the tube, inability to withdraw the tube and breakage of the mercury filled bag. On rare occasions it is difficult or impossible to withdraw the tube. This is particularly true if the tip of the tube has passed through the ileocecal valve. Should this occur patience will usually effect a successful outcome. Leaving the tube in place and attempting its removal an
Intestinal Intubation
157
hour or so later will frequently allow it to be dislodged and withdrawn. If one is still unable to withdraw it at this time continued forceful effort might result in tearing the intestine or its mesentery. It is, there-
fore, wiser to cut it off at the nose and to allow it to pass down through the intestine. The tube may remain in the intestine for many days before passing out through the rectum and anus. It has on occasion become twisted and caused an obstruction of the bowel necessitating surgical intervention. Occasionally the tip of the tube will appear at the anus while the proximal end still projects from the nose. In this case the proximal end should be cut off at the nose and the tube then withdrawn through the anus. Rupture of the mercury-filled bag in the intestine has failed to produce any serIOUS consequences. Chaffee suggests the following warnings to prevent complications: 1. Remove the tube in case of dyspnea, dysphagia, hoarseness or croupy cough. 2. The position of the tip of the tube should be changed daily. 3. The presence of esophageal varices is a contraindication to intestinal intubation. 4. Remove the tube as soon as its work is completed. 5. When the mercury bag has passed through the ileocecal junction, withdraw with extreme care under fluoroscopy, or cut off the tube at the nose and allow it to pass down the intestine. SUMMARY
In summary, intestinal intubation is an invaluable aid in the management of many surgical conditions of the bowel. However, because of the many possible pitfalls, its use requires an intelligent and vigilant attitude on the part of the physician. REFERENCES Berry, R. E. L.: Diagnosis and Treatment of Acute Intestinal Obstruction. J.A. M.A. 148: 347-355 (Feb. 2) 1952. Cantor, M. 0.: Intestinal Intubation. 1st Ed. Springfield, Ill., Charles C Thomas, 1949. Chaffee, J. S.: Complications of Gastrointestinal Intubation. Ann. Surg. 130: 113-123, 1949. Johnston, C. G.: Decompression in the Treatment of Intestinal Obstruction. Surg., Gynec. & Obst. 70: 365-369, 1940. Wangensteen, O. H.: Intestinal Obstructions. 2nd Ed. Springfield, Ill., Charles C Thomas, 1942. 25 E. Washington Street Chicago 2, Illinois