Short bowel syndrome overview: Difference between revisions
| Line 63: | Line 63: | ||
===Other Diagnostic Studies=== | ===Other Diagnostic Studies=== | ||
There are no other diagnostic studies associated with short bowel syndrome. | |||
==Treatment== | ==Treatment== | ||
Revision as of 15:33, 11 December 2017
|
Short bowel syndrome Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Short bowel syndrome overview On the Web |
|
American Roentgen Ray Society Images of Short bowel syndrome overview |
|
Risk calculators and risk factors for Short bowel syndrome overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sadaf Sharfaei M.D.[2]
Overview
Short bowel syndrome is a malabsorption disorder caused by the surgical removal of the small intestine, or rarely due to the complete dysfunction of a large segment of bowel. Most cases are acquired, although some children are born with a congenital short bowel. It does usually not develop unless a person has lost more than two-thirds of their small intestine.
Historical Perspective
The first successful intestinal resection was performed in 1880. In 1935, Haymond following research on many patients with bowel resection, reported that 30 to 50% loss of bowel was well tolerated. Total parenteral nutrition (TPN) was introduced during 1960s which helped patients to survive following bowel resection.
Classification
Based on the length of the remaining bowel, short bowel syndrome may be divided into three types such as end-jejunostomy, jejunocolonic anastomosis, ileocolonic anastomosis. They have different progress from mild to severe dysfunction. All of them require home parenteral nutrition except ileocolonic anastomosis which has excellent prognosis and rarely needs parenteral nutrition. Based on the etiology, short bowel syndrome may be divided into three categories such as vascular abnormalities, mucosal disease of intestine and causes without preexisting intestinal disease.
Pathophysiology
Causes
Short bowel syndrome in adults is usually caused by surgical removal of the intestine due to different diseases including Crohn's disease, mesenteric ischemia, malignancies or radiation enteritis. Less common causes include trauma, volvulus, adhesion and iatrogenic surgery on gastrointestinal system.
Differentiating short bowel syndrome from Other Diseases
Epidemiology and Demographics
The incidence and prevalence of short bowel syndrome is difficult to estimate. All the data is derived from patients receiving home parenteral nutrition. Therefore, there are different distributions around the world. The incidence of short bowel syndrome was estimated to be 1-2 cases per 100,000 individuals worldwide per year. The prevalence of short bowel syndrome is approximately 0.3-0.4 per 100,000 individuals in the USA to 0.1-4 per 100,000 individuals in Europe. It affects all age groups. There is no racial predilection to short bowel syndrome and is reported worldwide. Short bowel syndrome affects men and women equally.
Risk Factors
Common risk factor in the development of short bowel syndrome may be iatrogenic including any operation on the gastrointestinal system.
Screening
There is insufficient evidence to recommend routine screening for short bowel syndrome.
Natural History, Complications, and Prognosis
The symptoms of short bowel syndrome usually develop immediately following bowel resection. Diarrhea may cause massive fluid and electrolyte loss. Immediately after surgery, intestinal adaptation develops in three phases, including acute, adaptive and maintenance phase. During the adaptation, structural, motility and functional changes happen. Patients need hydration and nutritional support via parenteral, enteral and oral routes. Length of remaining small bowel is the most important prognostic factor. patients with more than 200 cm length of small bowel, usually does not need parenteral nutrition. Patients with shorter small bowel may not weaned off from parenteral nutrition support. Complications might happen due to malnutrition, surgery and parenteral nutrition. Malnutrition presents with vitamin, mineral and essential fatty acids deficiencies. Complications related to surgery including thrombosis, infection, hemorrhage, atelectasis and anastomosis disruption might occur. Small intestinal bacterial overgrowth due to stasis and obstruction might happen. Chronic liver disease following parenteral nutrition is a common complication in short bowel syndrome. There is no definite cure for short bowel syndrome. However, medications and nutritional therapy significantly improve the quality of life and survival of the patients. Prognosis of short bowel syndrome depends on the location and size of the bowel resection, underlying pathology, nutrition support, pharmacotherapy, and extent of intestinal adaptation. The 2 and 5-year survival rate of patients with short bowel syndrome are approximately 80% and 70%, respectively.
Diagnosis
Diagnostic Criteria
Short bowel syndrome is mainly diagnosed based on clinical presentation. There are no established criteria for the diagnosis of Short bowel syndrome. History of bowel resectionand clinical manifestation including diarrhea and malnutrition would confirm the diagnosis.
History and Symptoms
The hallmark of short bowel syndrome is diarrhea. A positive history of operation on gastrointestinal system and symptoms of malabsorption is suggestive of short bowel syndrome. The most common symptoms of short bowel syndrome include dehydration, abdominal pain, and fatigue.
Physical Examination
Patients with short bowel syndrome usually appear weak and tired. Physical examination of patients with short bowel syndrome is usually remarkable for signs of malabsorption, dehydration and abdominal tenderness.
Laboratory Findings
Laboratory findings consistent with the diagnosis of short bowel syndrome include anemia, hypoalbuminemia, low level of vitamins, minerals, and micronutrients. Level of acute phase reactants is high. Abnormal liver function tests including elevated liver enzymes and bilirubin might be seen. Fluid and electrolyte imbalance might be present. Fecal fattest is usually positive.
Electrocardiogram
There are no ECG findings associated with short bowel syndrome. In case of malnutrition and electrolyte imbalance, an ECG may be helpful. Hypokalemia might present with arrhythmia, ST segment depression, low T wave, prominent U waves and QRS prolongation. Hypocalcemia might present with QT interval prolongation. Hypomagnesemia might present with QT interval prolongation and ventricular and supraventricular arrhythmia.
X-ray
An abdominal x-ray may be helpful in the diagnosis of short bowel syndrome. Abdominal x-ray helps to rule out ileus or intestinal obstruction. Upper gastrointestinal series might demonstrate strictures and dilation of the bowel.
Ultrasound
There are no echocardiography findings associated with short bowel syndrome. Ultrasound may be helpful in the diagnosis of complications of short bowel syndrome including gallstones and liver diseases. Doppler ultrasound might be used to diagnose venous thrombosis.
CT scan
Abdominal CT scan with contrast may be helpful in the diagnosis of short bowel syndrome complications including dilation, obstruction of the bowel and signs of liver diseases.
MRI
There are no MRI findings associated with short bowel syndrome.
Other Imaging Findings
There are no other imaging findings associated with short bowel syndrome.
Other Diagnostic Studies
There are no other diagnostic studies associated with short bowel syndrome.
Treatment
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
There are several ways to prevent complications of short bowel syndrome. Management strategies and regular follow-up are needed to find and treat complications accordingly. Effective measures must be done for secondary prevention of complications following total parenteral nutrition including liver disease, cholelithiasis, kidney stone, small bowel bacterial overgrowth, lactic acidosis, lactic acidosis. Hydration, consuming supplements, antibiotic therapy, and regular monitoring with blood tests, ultrasound and scans are recommended.