Intestinal obstruction (ileus) refers to the inability of the intestinal contents to pass and run smoothly in the intestine. When the passage of intestinal contents is blocked, a series of symptoms such as abdominal distension, abdominal pain, nausea and vomiting, and bowel obstruction can occur. Intestinal obstruction is one of the common acute abdominal diseases.
I. Symptoms and signs
1.Symptoms Acute intestinal obstruction has four main symptoms.
(1) Abdominal pain: it is paroxysmal colic. For jejunal or upper ileal obstruction, there is one attack every 3-5 minutes, and for terminal ileal or large intestinal obstruction, there is one attack every 6-9 minutes, with pain relief in the interval between attacks, accompanied by hyperactive bowel sounds during colic. The bowel sounds are high pitched. Sometimes the sound of air over water can be heard. Paralytic intestinal obstruction may have no abdominal pain, high small bowel obstruction may have less severe colic, and intermediate or low bowel obstruction may have typically severe colic, located around the umbilicus or poorly localized. Each colic may last from a few seconds to several minutes. If the paroxysmal colic turns into persistent abdominal pain, the development of strangulated intestinal obstruction should be considered.
(2) Vomiting: After the obstruction, the retrograde peristalsis of the intestinal tube causes the patient to vomit. The vomit starts with stomach contents and later with intestinal contents. High small intestinal obstruction is not severe in colic, but vomiting is frequent. In middle or distal small intestine obstruction, vomiting appears later, and in low small intestine obstruction, vomit is sometimes “feculent vomitting” due to the retention of intestinal contents and the overgrowth of bacteria, which decompose intestinal contents.
(3) Abdominal distension: it occurs mostly in the late stage, and high small bowel obstruction is not as obvious as low one, while colonic obstruction rarely occurs due to the presence of ileocecal valve, and the obstruction is often closed loop, so the abdominal distension is obvious. In strangulated intestinal obstruction, the abdomen is asymmetrically distended and the enlarged intestinal loops can be felt.
(4) Exhaustion and defecation stop: Patients with intestinal obstruction usually stop defecating and exhausting from the anus. However, mesenteric vascular embolism and intussusception can discharge loose stool or bloody mucus. Patients with colon tumor, diverticulum or gallstone obstruction also often have black stools.
2.Signs
(1) Heart rate: in simple intestinal obstruction, when water loss is not heavy, the heart rate is normal. Accelerated heart rate is a manifestation of hypovolemia and severe water loss. In strangulated intestinal obstruction, the heart rate is accelerated more obviously due to the absorption of toxins.
(2) Body temperature: normal or slightly elevated. Elevated body temperature is a sign of intestinal strangulation or intestinal necrosis.
(3) Abdominal signs: attention should be paid to the presence of surgical scars. Obese patients should pay particular attention to inguinal and femoral hernias, which are easily ignored because of excessive subcutaneous fat. The distended intestinal canal is accompanied by intestinal pattern or peristaltic wave when there is pressure pain and colic. If localized pressure pain is accompanied by abdominal muscle tension and rebound pain, it is a sign of strangulated intestinal obstruction. The change of intestinal sound tone should be noted during auscultation. When colic is accompanied by air over water sound, the intestinal canal is highly dilated, and the metallic sound of “tinkling” (high tone) can be heard.
(4) Rectal palpation: pay attention to whether there is a tumor in the rectum and whether there is fresh blood in the finger sleeve. The presence of fresh blood should be considered as intestinal mucosal lesions, intestinal entrapment, thrombosis and other lesions.
II. Treatment with medicine
The treatment of intestinal obstruction lies in relieving the obstruction and restoring the patency of the intestinal canal. It is worth noting that the threat to the patient’s life does not lie entirely in the intestinal obstruction itself, but in the systemic pathophysiological changes caused by the intestinal obstruction. In order to save the patient’s life, water and electrolyte disorders should be corrected in time to reduce intestinal lumen distension. Surgical treatment should be carried out after the systemic pathophysiological changes are corrected.
1, gastrointestinal decompression Once the patient’s diagnosis is clear, gastrointestinal decompression should be performed to reduce abdominal distension. In elderly patients, it can also prevent the occurrence of misaspiration. Keeping the gastric tube in the stomach can aspirate the liquid and gas backflowing from the intestinal tube into the stomach, thus reducing the degree of intestinal distension and facilitating surgical exploration. For simple adhesive intestinal obstruction, gastrointestinal decompression with intravenous fluids alone can sometimes relieve the obstruction and avoid reoperation. After applying gastrointestinal decompression for 12h, repeat X-ray examination, if the inflation of small intestine is reduced and the colon is inflated, it is proved that the intestinal obstruction is relieved.
2.Supplementation of water and electrolytes According to the site of intestinal obstruction, the duration of obstruction, and the results of laboratory examination, the supplementation of water and electrolytes should be carried out. Since the fluid lost by vomiting and gastrointestinal decompression is similar to extracellular fluid, the supplemental fluid is mainly isotonic fluid. Preoperative blood volume replacement is particularly important in severely dehydrated patients, as it can otherwise cause a drop in blood pressure in the presence of anesthesia. In strangulated intestinal obstruction, in addition to the supplementation of isotonic fluids, the supplementation of plasma and whole blood is especially important, especially when blood pressure and pulse rate have been changed.
3.Application of antibiotics Simple intestinal obstruction does not require the application of antibiotics. For strangulated intestinal obstruction, antibiotics should be used to reduce bacterial multiplication, especially when peritonitis is caused by necrosis of the intestinal tube.
4.Surgical treatment After the above treatment, some patients can be relieved. If abdominal pain worsens, vomiting does not stop, white blood cells increase, and body temperature also increases, surgical treatment is necessary. The duration of observation should not exceed 48h to avoid necrosis of intestinal strangulation. Surgical methods vary according to the cause of obstruction, and there are generally four methods.
(1) adhesiolysis and repositioning: if there is no hemorrhagic exudate on open exploration, it is mostly simple obstruction. If the intestinal distension is not serious, the junction of intestinal atrophy and dilatation, where the obstructive lesion is located, can be traced from top to bottom. Then, depending on the cause, adhesion release or intestinal torsion or intussusception repositioning can be performed. If the intestinal canal above the obstruction is obviously swollen, the swollen intestinal canal should be decompressed first to avoid rupture due to straining during the exploration.
(2) Short-circuit anastomosis between intestinal loops: if the cause of obstruction cannot be removed, such as cancer, radiation enteritis, abdominal tuberculosis and other adhesions caused by very serious, difficult to separate. Forced separation often breaks the intestinal canal, and postoperative intestinal fistula occurs, so short-circuit anastomosis can be performed between the upper and lower intestinal segments at the obstruction site. There are generally two types of anastomosis.
① Lateral anastomosis: Lateral anastomosis is performed between the intestinal loops above and below the obstruction. This type of anastomosis will form a blind loop between the anastomosis and the obstruction, which may later produce blind loop syndrome and sometimes ulcer formation causing intestinal bleeding.
(2) End-lateral anastomosis: Cut off the proximal intestine of the obstruction and perform end-lateral anastomosis with the distal intestine of the obstruction.
(3) Enterostomy: generally applicable to colonic obstruction, such as sigmoid colon cancer combined with obstruction. The intestinal canal above the obstruction is swollen with severe edema, and the intestinal cavity is infected, so the first-stage surgical resection and anastomosis often invites anastomotic leakage. Therefore, for colonic obstruction, fistula is often performed above the obstruction first. However, small bowel obstruction, especially high obstruction, should not be performed fistula, otherwise it will produce serious fluid loss and abdominal wall skin erosion, and it is difficult to maintain the nutrition of patients with long-term fistula.
(4) bowel resection and intestinal anastomosis: for necrosis of the intestinal wall caused by obstruction, a phase of resection and anastomosis should be performed. For intestinal torsion, mesenteric vascular embolism of intestinal obstruction. Both should be performed after resection of necrotic intestine to the opposite end anastomosis is ideal. Patients in shock, who are in critical condition, should not extend the operation time, but resection of necrotic intestinal canal is equal to removal of the lesion, and sometimes blood pressure can be restored. The surgical procedure should be as meticulous as possible, and the torn plasma membrane surface should generally be patched with fine silk sutures or covered by sutures from the adjacent small intestinal plasma membrane surface to avoid exposure of the rough surface and future adhesions. Before suturing the peritoneum, the small intestine is properly arranged, hoping to form a neat parallelepiped between the mesentery without distortion.
III. Dietary care
Seafood such as white fish, yellow fish, silver fish, and crustaceans such as oysters and crabs can enhance immune function, repair damaged tissue cells, and protect from viral invasion. However, it should be properly selected and cooked, otherwise it will be food poisoning, steaming should be heated at 100 degrees for more than half an hour. If you are allergic to seafood, you should not eat it. You can eat more mushrooms, silver fungus, seaweed, nori, etc. Watermelon has a clear heat detoxification, thirst, diuretic and hypotensive, rich in sugar, vitamins and protease, etc.. Protease can convert insoluble protein into soluble protein. Potassium-rich food kelp, rice bran and wheat bran, almond fruit, Cheng, raisins, bananas, plums, melon seeds.
Fourth, preventive care
1, mechanical intestinal obstruction. Treat the original disease (such as: pediatric congenital intestinal stenosis, intestinal wall tumor, intestinal stone, roundworm mass, extra-abdominal hernia embedded, etc.) to prevent the progress of the disease and the emergence of intestinal obstruction.
2.Adhesive intestinal obstruction. Mostly secondary to post-operative laparotomy, peritonitis, injury, bleeding, etc. Therefore, it is necessary to get out of bed as early as possible after surgery.
V. Pathological etiology
1. According to the causes of intestinal obstruction, there are three categories.
(1) Mechanical intestinal obstruction: common etiologies include
(1) Intestinal foreign body: intestinal stone, parasite, large gallstone and fecal mass blockage or embedment.
(2) Intestinal polyp, neoplasm, benign and malignant tumor or lymphoma blockage.
(iii) Intestinal overlap.
④Intestinal congenital anomalies: including congenital intestinal atresia, intestine with congenital fibrous curtain or web formation, Meckel’s diverticulum stenosis, etc. Congenital anomalies of the intestine are generally less common.
⑤ Inflammatory lesions of the intestine or peritoneum: such as intestinal tuberculosis, Crohn’s disease, tuberculous peritonitis, radiation enteritis and strictures due to inflammatory ulcers of the intestine caused by drugs such as NSAIDs.
(6) Intestinal adhesions: often due to post-operative abdominal or pelvic surgery, or chronic inflammatory lesions in the abdominal cavity (such as tuberculous peritonitis, Crohn’s disease). Intestinal adhesions occur more often after surgery than small intestine adhesions.
(7) Hernia: such as inguinal hernia, intra-abdominal hernia, including intra-retinal sac hernia, femoral hernia, etc., occurring embedded.
(8) Intestinal torsion: torsion is usually caused by mesenteric tumor or stenosis at its base.
(9) Compression by extra-intestinal tumors: such as huge tumors in the abdominal cavity, omentum and mesentery, huge retroperitoneal tumors, pancreatic pseudocysts, etc. can compress the intestinal canal and cause intestinal obstruction in severe cases. In recent years, there is an increasing trend of intestinal obstruction caused by extra-intestinal compression.
(2) Motility disorder intestinal obstruction: motility disorder intestinal obstruction is due to the disorder of intestinal wall muscle activity, resulting in intestinal contents can not run, rather than intestinal obstruction caused by mechanical factors inside and outside the intestinal cavity, so it is also called pseudo intestinal obstruction. Its etiology includes.
①Post-surgical paralytic intestinal obstruction: it is commonly found after surgery.
② Non-surgical paralytic intestinal obstruction.
Disease diagnosis
Strangulated intestinal obstruction is one of the acute abdominal diseases, so it often needs to be distinguished from peptic ulcer perforation, acute severe pancreatitis, gallbladder perforation, acute appendicitis or appendiceal perforation. Generally speaking, based on the clinical manifestations, laboratory tests, X-ray examinations or CT and MRI examinations of each of the above diseases, the differential diagnosis is often not difficult.
VII. Examination methods
Laboratory tests.
1.Hemoglobin and white blood cell count? are normal in the early stage of intestinal obstruction. When the obstruction is prolonged and dehydration signs appear, hemoglobin concentration and leukocyte elevation can occur. When leukocytes are increased and left shift is present, it indicates the presence of intestinal strangulation.
2. Measurement of serum electrolytes (K, Na, Cl-), carbon dioxide binding capacity, blood gas analysis, urea nitrogen, and blood cell pressure are important. It is used to determine dehydration and electrolyte disturbance. And to guide the fluid input.
The determination of serum inorganic phosphorus, creatine kinase and isoenzyme is important for the diagnosis of strangulated intestinal obstruction. Many experiments have proved that inorganic phosphorus and creatine kinase in blood are increased when the intestinal wall is ischemic and necrotic.
Other auxiliary examinations.
1.X-ray examination X-ray examination is very important for the diagnosis of intestinal obstruction. After the jejunum and ileum are filled with gas, their X-ray images have their own characteristics: jejunal mucosal folds are arranged parallel to the mesenteric margin in a fishbone shape, and the gap is regular like a spring; ileal mucosal folds disappear, and the outline of the intestinal tube is smooth; colonic distention is located at the periphery of the abdomen, showing colonic pouch shape.
X-ray manifestation of small intestinal obstruction: pneumatization and fluid accumulation in the intestinal canal above the obstruction with dilatation of the intestinal canal. The fluid surface appears in the intestinal lumen soon after the obstruction. The longer the time of obstruction, the more fluid there is. Low-level obstruction has more fluid. The fluid surface usually appears after 5 to 6 h of obstruction. A step-like fluid plane of varying length can be seen on standing examination. The distribution of distended bowel loops can be seen in the prone position, with the small intestine in the center and the colon occupying the periphery of the abdomen. In high jejunal obstruction, a large amount of gas and fluid is seen in the stomach. In low small bowel obstruction, there are more fluid planes. In complete obstruction, there is no gas or only a small amount of gas in the colon.
Manifestations of strangulated intestinal obstruction: round or lobulated soft tissue masses are imaged in the abdomen. Individual distended fixed bowel loops with “C” shaped dilatation or “coffee bean sign” can also be seen.
In paralytic intestinal obstruction, the small intestine and colon are uniformly dilated, but there is less pneumatization and fluid in the intestinal canal. In case of paralytic intestinal obstruction caused by peritonitis, there is exudative fluid in the abdominal cavity and the intestinal canal floats in it. The intestinal canal spacing is widened, the edges are blurred, and the jejunal mucosal folds are thickened.
2.B-type ultrasonography. Soft masses can be formed in the abdomen, and intestinal lumen acoustic peristalsis can be seen, and fluid retention can be seen. The intestinal lumen sound image can be seen in concentric circles, with strong echogenicity in the center of the circle, and multi-layer tube wall structure can be seen in the longitudinal plane. The use of B-mode ultrasound to diagnose intestinal obstruction is subject to further study and improvement.
VIII. Complications
When the passage of intestinal contents is obstructed, a series of symptoms such as abdominal distension, abdominal pain, nausea and vomiting, and bowel obstruction can be produced.
IX. Prognosis
Although acute intestinal obstruction is treated, it still has a certain morbidity and mortality rate, which has decreased in recent years. After 1990, the mortality rate has been reduced from 2% to zero except for the death of obstruction caused by advanced tumor in North Medical University Hospital No.1. The mortality rate depends on the type of intestinal obstruction; Milamend reported that the mortality rate of simple intestinal obstruction was 0%-5% and strangulated obstruction was 4.5%-30% in the past 20 years. In addition, the age of the patient also has an impact, with more comorbidities and higher mortality rates in the elderly. The timeliness of surgery also has an impact on the life of the patient, as shown by Wangensten’s data. If surgery is performed within 36h of the onset of strangulated obstruction, the morbidity and mortality rate is about 8%, and if surgery is performed after 36h of the onset, the morbidity and mortality rate is 25%. Therefore, early diagnosis and timely surgery are the keys to treat strangulated intestinal obstruction to reduce the morbidity and mortality rate.