mechanical obstruction & non mechanical obstruction

Causes of non-mechanical obstruction

-MOST COMMON: handling of intestines during sx -intestinal function is lost for a few hours or days -may be caused by peritonitis due to leakage of colonic contents- irritation and inflammation -vascular insufficiency- embolus decreases blood flow to the mesenteric blood vessels- severe insufficiency can cause blood infarct

non-mechanical obstruction

paralytic ileus or adynamic ileus peristalsis is decreased or absent d/t neuromuscular disturbances, results in slowing of the movement or backup of bowel contents

Causes of mechanical obstruction

adhesions- scare tissue from sx benign or malignant tumors appendicitis complications hernias fecal impaction structures due to crohns dz or radiation treatment

manifestations of a non mechanical obstruction

abd distention constant, diffuse discomfort decrease in bowel sounds is early absent bowel sounds is late

mechanical obstruction

bowel is physically blocked by problems outside the intestines (adhesions) in the bowel wall (crohns dz) or in the intestinal lumen (tumors)

Causes of mechanical obstruction: fibrosis

due to endometriosis

Causes of mechanical obstruction: vascular dz

emboli and arteriosclerotic narrowing of mesenteric artery

manifestations of a non mechanical obstruction: vomiting

gastric contents bile no foul smell

manifestations of mechanical obstruction

mid abd pain or cramping vomiting- bile, mucus, orange-brown, foul smell obstipation- no passage of gas or stool, in complete obstruction diarrhea- may be present in partial obstruction alteration in bowel pattern and stool abd distention *borborgymi- proxmial high pitched bowel sounds abd tenderness

Causes of mechanical obstruction: intussusception

telescoping segment of intestines within itself

manifestations of a non mechanical obstruction: obstipation

this may or may no be present with a non mechanical obstruction

hypokalemia

this predisposes a patient to a paralytic ileus (non mechanical)

Causes of mechanical obstruction: volvulus

twisting of intestine