[07.03] CM - Obstruction in Adults V2.pdf

Obstruction

What term describes the prevention of intestinal contents from moving distally?

Ileus

What term defines severely impaired transit of intestinal contents due to decreased peristaltic activity in the absence of mechanical obstruction?

Small intestine

In which part of the gastrointestinal tract does an ileus typically occur?

Non-surgical

Is paralytic ileus classified as a surgical or non-surgical condition?

Mechanical obstruction

What condition is characterized by severely impaired transit of intestinal contents due to intrinsic luminal obstruction or extrinsic compression?

Intrinsic obstruction

What type of mechanical obstruction indicates a problem located within the intestinal lumen?

Extrinsic obstruction

What type of mechanical obstruction indicates an obstruction originating outside the intestinal wall?

Colonic pseudo-obstruction

What condition is defined as severe functionally impaired transit of colonic contents and massive colonic dilatation without mechanical blockage?

Ogilvie's syndrome

What is the clinical eponym for acute colonic pseudo-obstruction?

Large intestine

Which division of the gastrointestinal tract is primarily involved in colonic pseudo-obstruction?

Uncoordinated, nonperistaltic, or attenuated colonic muscle contractions

What underlying muscular dysfunction causes colonic pseudo-obstruction?

Dynamic obstruction

In which type of bowel obstruction does active peristalsis work against a mechanical barrier?

Volvulus, incarceration, obstruction, and intussusception

What are the four primary mechanisms of dynamic bowel obstruction?

Impaction, foreign bodies, bezoars, and gallstones

What are the four intraluminal causes of dynamic bowel obstruction?

Bezoars

What term describes masses of partially digested food or material formed around the gastrointestinal tract?

Strictures, masses, and malignancies

What are three intramural causes of dynamic bowel obstruction?

Malignancy / Mass

Which intramural cause is tied with inflammation as the second most common cause of dynamic obstruction in adults at 15%?

Adhesions or bands

What is the single most common overall cause of dynamic bowel obstruction in adults, accounting for 40% of cases?

Congenital defects or postoperative conditions

What are the two most common underlying origins of abdominal bands or adhesions?

Incarcerated / Obstructed hernia

What is the third most common cause of dynamic bowel obstruction in adults, accounting for 12% of cases?

Adynamic obstruction

What type of bowel obstruction is characterized by either absent peristalsis or non-propulsive motility without physical blockage?

Paralytic ileus

In which adynamic condition is intestinal peristalsis completely absent?

Mesenteric vascular occlusion and colonic pseudo-obstruction

In which two conditions is peristalsis present but in a non-propulsive form?

Dilation and altered motility

What two physiological changes develop in the bowel proximal to a mechanical obstruction?

Contracts and becomes immobile

What happens to the bowel distal to a mechanical obstruction over time?

Increases

How does peristalsis proximal to an obstruction initially respond to overcome the blockage?

Reduction in peristaltic strength, flaccidity, and paralysis

What happens to the proximal bowel if a mechanical obstruction remains unrelieved?

Noisy or hyperactive bowel sounds

What auscultatory finding is heard proximal to a mechanical obstruction during physical exam?

Normoactive bowel sounds

What auscultatory finding is heard distal to a mechanical obstruction early in the disease course?

Silent abdomen

What auscultatory finding develops when a mechanical obstruction persists unrelieved?

Gas accumulation and fluid sequestration

What two primary factors produce abdominal distention in intestinal obstruction?

Aerobic and anaerobic bacterial growth

What mechanism generates intestinal gas in an obstructed bowel loop?

Nitrogen (90%) and hydrogen sulphide

Which two gases constitute the majority of intestinal gas produced during obstruction?

Unabsorbed digestive juices

What is the source of intraluminal fluid accumulated during bowel obstruction?

Nasogastric tube (NGT) insertion

What non-surgical intervention is used to decompress gas and fluid from the proximal gastrointestinal tract?

Reduced oral intake, defective intestinal absorption, vomiting, and luminal sequestration

What four factors cause dehydration and electrolyte loss in bowel obstruction?

5%

What percentage of acute surgical admissions are accounted for by small intestinal obstruction?

16%

What percentage of colorectal malignancies present with bowel obstruction?

Esophageal strictures, webs/rings, esophageal carcinoma, gastric carcinoma, and pyloric stenosis

What are five major risk factors for esophago-gastric obstruction?

Post-operative adhesions

What is the most common cause of small bowel obstruction, accounting for 60% of cases?

Strangulated hernia

What is the second most common cause of small bowel obstruction, accounting for 20% of cases?

Malignancy and volvulus

Which two conditions each account for 5% of small bowel obstruction cases?

Colorectal malignancies

What is the leading overall cause of large intestine obstruction?

25%

What percentage of patients presenting with large bowel obstruction secondary to colorectal cancer have distant metastases?

Sigmoid colon

What is the most common anatomical site for an intestinal volvulus in the large bowel?

5%

What percentage of large bowel obstructions are caused by sigmoid volvulus?

Reduced density of interstitial cells of Cajal

What physiological cell deficiency in the colon is associated with chronic intestinal pseudo-obstruction?

Coronary artery bypass grafting (CABG)

What specific operative procedure is most commonly associated with Ogilvie's syndrome?

Diffuse, central, colicky abdominal pain

What is the classic character and distribution of pain in acute bowel obstruction?

Paralytic ileus

In which intestinal condition is abdominal pain minimal or entirely absent?

Proximal small bowel obstruction

Which level of bowel obstruction presents with earlier onset of symptoms and prominent vomiting?

Distal / Low bowel obstruction

Which level of bowel obstruction takes longer to present and causes more marked abdominal distention?

The lower the level of obstruction, the more marked the distention

How does the anatomical level of obstruction affect the degree of abdominal distention?

Early in low obstruction, late in high obstruction

When does absolute constipation present in low versus high bowel obstruction?

Intestinal ischemia or perforation

What two critical surgical complications are suggested by severe abdominal pain and marked tenderness?

Visual inspection for dehydration, abdominal distention, and visible peristalsis

What three general features should be observed during physical examination for obstruction?

Pyrexia / Fever

What physical exam finding indicates dehydration or a systemic inflammatory reaction in an obstructed patient?

Nasogastric tube (NGT)

What device provides intestinal decompression and allows recording of output volume and character?

Gastric or bilious output

What type of NGT drainage indicates a proximal GI obstruction?

Fecaloid output

What type of NGT drainage indicates a distal intestinal obstruction?

Foley catheter

What device is inserted to monitor urine output and assess adequacy of hydration during resuscitation?

Supine and upright views

What two minimum abdominal radiograph views must be ordered when evaluating bowel obstruction?

Upright view

Which abdominal radiograph view best demonstrates differential air-fluid levels characteristic of mechanical obstruction?

Supine view

Which radiograph view shows diffuse bowel dilation where ileus and mechanical obstruction can look similar?

Dilated small bowel loops centrally located with no rectal gas

What plain radiograph pattern indicates a distal small bowel obstruction?

Gastroenteritis and acute pancreatitis

What are two non-surgical gastrointestinal differential diagnoses for bowel obstruction?

Gut ischemia and gut perforation

What are two intra-abdominal emergencies that mandate immediate surgical intervention?

Gastrointestinal tuberculosis

What infectious etiology is a common non-pulmonary cause of bowel obstruction in the Philippines?

Myocardial infarction and ovarian cancer

What are two non-gastrointestinal conditions that can mimic bowel obstruction?

Mechanical obstruction

In which condition is motility initially increased then decreased, with an obliterated lumen, radiologic cut-off point, and surgical treatment?

Ileus

In which condition is motility decreased/absent, without lumen obliteration or radiologic cut-off, treated conservatively?

Acute colonic pseudo-obstruction

Which condition presents acutely with massive colonic dilatation, non-obliterated lumen, and usually responds to conservative care or neostigmine?

Inflammation, strictures, tumors, diaphragmatic anomalies, foreign bodies, iatrogenic causes, caustic ingestion, and pyloric stenosis

What are eight causes of esophago-gastric obstruction?

Malignant and benign (congenital or acquired)

What are the two major categories of esophageal strictures?

Schatzki ring, foreign bodies, and caustic injuries

What are three examples of acquired benign esophageal strictures?

Squamous cell carcinoma

Which esophageal cancer type was historically most common, tends to be multicentric, and most frequently involves the middle third?

African-American race, alcohol, cigarettes, untreated achalasia, caustic injury, nutritional deficiencies, nitrosamines, and dietary customs

What are eight risk factors for esophageal squamous cell carcinoma?

Adenocarcinoma

Which esophageal cancer type currently constitutes the majority of cases, shows submucosal invasion, and most commonly involves the distal esophagus?

White race, GERD, Barrett esophagus, obesity, and cigarette smoking

What are five risk factors for esophageal adenocarcinoma?

Progressive dysphagia to solid food

What is the cardinal presenting symptom of esophageal carcinoma?

12 mm

Below what luminal diameter does esophageal narrowing typically produce dysphagia?

Esophagoscopy with biopsy

What diagnostic procedure is required to provide a definitive tissue diagnosis and exclude malignancy in esophageal obstruction?

Computed tomography (CT) scan

Which imaging modality determines the peripheral extent of an esophageal tumor and assesses lymph node involvement?

Endoscopic Ultrasonography (EUS)

Which diagnostic tool is increasingly used to assess the depth and local staging of esophageal malignancies?

Dilation, surgical resection, chemotherapy, and radiotherapy

What are four treatment modalities for esophageal obstruction?

Peptic ulcer disease and caustic injury

What are the two most common underlying causes of gastric outlet obstruction?

Esophagus and pylorus

Which two anatomical regions are most severely damaged following caustic substance ingestion?

Male gender, polyposis family history, high nitrate/salt/pickled food diet, adenomatous polyps, smoking, H. pylori, and chronic gastritis

What are seven risk factors for gastric adenocarcinoma?

Incurable metastatic gastric adenocarcinoma

What do classic clinical signs such as Virchow's node, Sister Mary Joseph's node, and Blumer's shelf indicate?

Virchow's node

What term describes an enlarged supraclavicular lymph node associated with metastatic gastric cancer?

Sister Mary Joseph's node

What term describes metastatic cancer infiltration of the umbilicus?

Blumer's shelf

What term describes a palpable mass or fullness in the pelvic cul-de-sac on rectal or vaginal examination?

Krukenberg's tumor

What term describes metastatic gastric adenocarcinoma involving the ovaries?

Esophagogastroduodenoscopy (EGD) with biopsy

What is the gold standard procedure for definitive diagnosis and tissue biopsy of gastric adenocarcinoma?

2nd and 3rd portions of the duodenum

How far distally can a standard upper GI endoscopy visualize?

Retroflexion

What endoscopic maneuver allows visualization of the gastric fundus and gastroesophageal junction?

Abdominal pain, nausea, vomiting, dysphagia, gastric reflux, unexplained weight loss, anemia, and upper GI bleeding

What are eight clinical indications for upper GI endoscopy?

Ulcers, abnormal growths, precancerous lesions, bowel obstruction, inflammation, and hiatal hernia

What are six conditions detected by upper GI endoscopy?

Adhesions, tumors, intussusception, strictures, foreign bodies, inflammatory bowel disease, and congenital anomalies

What are seven general causes of intestinal obstruction?

Duodenal atresia, annular pancreas, malrotation, and volvulus

What are four congenital anomalies that cause intestinal obstruction?