Bowel Obstruction Flashcards
Partial vs complete bowel obstruction
Partial- fluid or air continue to pass
Complete- cessation of passage of stool or flatus
Categories of bowel obstruction causes
Extrinsic/extra luminal (external to bowel)
Intrinsic (within wall of bowel)
Intraluminal (defect that prevents passage of GI contents)
What is happening in the bowel during an obstruction?
Bowel dilatation and retention of fluid within lumen proximal to obstruction while distal the bowel decompresses (swallowed air and gas from fermentation contribute to distention)
Why are pts with an obstruction usually dehydrated?
Edematous bowel leads to fluid sequestration so depletes volume
How do complications result from bowel obstructions?
Dilatation–poor vascular supply and perfusion–ischemia–necrosis–perforation–peritonitis
Most common obstruction
SBO
Most common causes of SBO
Adhesions MOSTLY (from prior abdominal/pelvic surgery) Hernia (abd wall/groin) Neoplasm (primary or metastatic tumor) Or intestinal inflammation/abscess, strictures, FB ingestion, intussusception, volvulus
What questions can be asked to determine if IBD associated with SBO?
N/v/d, constipation, hematochezia and length
Presentation of SBO
Maybe fevers/chills Abd pain (initially can be periumbilical, intermittent and crampy) and more focal can be peritonitis Bloating/distention, anorexia, n/v, hematochezia, obstipation (can't pass)
Red flags to indicate peritonitis on SBO exam
Shock vitals (tachycardia and hypotension)
Lying motionless
Hypoactive/absent bowel sounds (late phase)
Peritoneal signs (guarding, rigidity, rebound tenderness)
Diagnostics used in SBO
CBC/CMP Amylase/lipase UA (and elevated specific gravity) Lactate/LDH Plan abd films
Why is a CT scan helpful for SBO?
ID location, severity, etiology and complications
What is seen on a supine and upright abd x-rays for SBO?
Dilated loops of bowel with air fluid levels
Proximal bowel dilatation with distal bowel collapse
Look for free air consistent with perforation
What is seen on CT abd for SBO?
Dilated proximal bowel with distal collapsed loops
Bowel wall thickening > 3 cm
Submucosal edema
What other imaging can be used for SBO when xray and CT are contraindicated (pregnant, kidney function, allergy)?
Abd u/s
CT/MR enterography
UGI/SBFT
Management of SBO
Admit
Non operative (NPO, IVF, lytes, NG tube, anti-emetics)
Gastrograffin (diagnostic and therapeutic)
Monitor over 2-5 days
Indications for surgical exploration of SBO
Complicated bowel obstruction
Intestinal strangulation
Worsening sxs or unresolved with NG tube and bowel rest
Signs of complete bowel obstruction
Ischemia, necrosis, perf
Worsening abd pain, fever, tachycardia, leukocytosis, metabolic acidosis, peritonitis
Signs of peritonitis
Pts look sick, lie still to minimize discomfort, hypoactive/absent bowel sounds, peritoneal signs, significant pain with light bumps
Causes of intestinal strangulation
Strangulated hernia
Volvulus
Intussusception
What is an ileus?
Hypomotility of GI tract in absence of mechanical bowel obstruction often secondary to post op abd surgery
Can be physiologic or pathologic (no return of function in 4-5 days)
Can be nonsurgical causes (hypomotility agents)
Presentation of ileus
Abd pain, distention, bloating, gassiness, n/c, can’t tolerate PO
What is seen on supine/upright abd films of ileus?
Dilated loops of bowel but air present in both small bowel and colon
No air fluid levels
Management for ileus
Support with IVF
Lyte management, pain (use NSAIDs), bowel rest (NPO/CL)
NG tube if persistent n/v
Causes of large bowel obstruction
Mostly adenocarcinoma (commonly colon and rectum) Stricture due to diverticulitis/ischemia, volvulus, IBD, fecal impaction, FBs
Presentation of LBO
Similar to SBO
Fever/chills, pain, bloating, constipation, n/v, tenderness, peritoneal signs maybe, hematochezia
Diagnostics for LBO
CBC, CMP, UA, LDH/lactate Plain abd films (supine and upright) CXR for free air Gastrograffin enema CT scan
What is seen on up right abd xrays for LBO?
Distended colon proximal to obstruction
Management for partial LBO
Surgical consult, NPO, IVF, abx, NG tube to decompress if vomiting
Avoid narcotics and anticholinergics
Management for complete LBO (based on cause)
Cancer/stricture-resection
Intussusception- barium enema
Fecal impaction-enema
Volvulus (sigmoid is resection and sigmoid is reduction)
Types of volvulus
Sigmoid (more common)
Cecal
Risk factors of sigmoid volvulus
About 70 YO Chronic constipation Redundant sigmoid colon Colonic dysmotility Hypomotility agents
Presentation of sigmoid volvulus
Cramping abd pain n/v Pain before vomiting Constipation Distended tympanitic abd TTP
Diagnostics of sigmoid volvulus
Upright abd xray
CT scan
Contrast enema (diagnostic and therapeutic)
Management to sigmoid volvulus
Flex sig to decompress and derotate
Surgery to resect redundant sigmoid colon and prevent recurrence
Mean age of cecal volvulus
33-53 (younger)
Presentation of cecal volvulus
Episodic pain of acute abd catastrophe
Distended abd
Tympanitis
Diagnostics for cecal volvulus
Upright abd xray (dilated cecum typically displaced medially superiorly) CT scan (diagnostic)
