Small & Large Bowel Obstruction

Terms in this set (47)

Small bowel obstruction
-Major causes:
1) Extra-luminal (adhesions, neoplasms, etc)
2) Intrinsic (intussception, Crohn's, etc)
3) Intra-luminal (gallstones, feces)
Post-op surgical adhesions (SBO)
-most of SBOs
-risk after abd surgery increases w/ time
SBO pathophysiology
-small bowel dilation proximal to obstruction-> fluid sequestration in lumen-> emesis, feculent or if excessive dilation then-> necrosis, perforation
-fluid losses
-bacteria thrive
Intravascular volme depletion
-vomiting
-3rd spacing
-decreased fluid intake
Presentation of SBO
-sxs will vary
-initially crampy abdominal pain then steady (bad sign-> dead bowel)
-abdominal distension (more w/ distal obstructions)
-N/V, anorexia, bloating
-constipation (passing flatus, no stool)
-obstipation (no flatus or stool-> bad sign)
-high pitched/ absent bowel sounds
-tympany on percussion, dilated proximal bowel loops
SBO PE
-Vitals: look for dehydration, tachycardia/ hypotension -> sepsis/ strangulation
-scars, hernias
-bowel sounds: high-pitched w/ rushes early, silent if late
-tympanitic to percussion
-diffuse abd tenderness
SBO labs
-altered e-lytes
-elevated BUN/Cr-> dehydration
-WBCs likely elevated
-increased hematocrit (hemoconcentration)
-LDH elevation-> sign of tissue breakdown
SBO diagnosis
1) Plain films (supine, upright): dilated bowel, air-fluid levels
2) CT scan (no contrast): when plain films negative, see bowel wall thickening (>3mm)
3) Upper GI & small bowel follow through: usually outpatient w/ recurrent SBO
-if very high suspicion call a surgeon
Red flags of SBO
-pneumperitoneum
-retroperitoneal air
-peritoneal signs
-shock
SBO management
1) Volume resuscitation, decompression w/ NG tube, NPO, abx
2) Consult surgeon
3) Reassess pt over next 2-3 d (correct e-lyte imbalances, assess fluid status, watch vitals)
-most will resolve spontaneously
Complete vs partial SBO
1) Complete: cessation of passage of stool or flatus
-absence of air or fluid in distal SB or colon=SBO
Indications for surgical exploration in SBO
-Complicated bowel obstruction
1) complete obstruction
2) closed loop obstruction
3) incarcerated hernia
4) bowel ischemia, necrosis or perforation
-highest complications w/incarcerated hernia, lowest w/ adhesive obstruction
Bowel ischemia w/ SBO
-high index of suspicion-> cut out
-possible signs: fever, leukocytosis, tachycardia, SIRS, acidosis, worsening abd pain, peritonitis
Malignant SBO
-primary or secondary tumor
-intrinsic or extrinsic compression
-can still be from adhesions or post-radiation fibrosis
-often non-operative
Peritonitis
-pt looks sick
-lie still-> minimize discomfort
-rebound tenderness, tenderness to percussion
-pain w/light palpation/ bumps
-diminished bowel sounds
Intussusceptions
-mostly in children, usually resolves spontaneously
-currant jelly stools
Paralytic ileus
-obstipation and intolerance of oral intake
-from non-mechanical factors
-decreased motility-> absent or hypoactive BS
-post-operatively bowel does not want to work-> more w/ larger incisions, lower abd operations
Pathologic ileus
-no return of bowel function in 4-6 d post-op
-absence of flatus or stool by POD #6
-N/V requiring cessation of PO intake
-requirement of NG tube after POD #5
-KUB-> dilated loops but air in both small bowel and colon, w/out transition zone
Diagnosis of paralytic ileus
-all same as SBO
-plain films: diffuse bowel dilation in small and large bowel
Management of paralytic ileus
1) Fluid/ e-lytes
2) Pain management (no narcotics)
3) NGT (in some)
4) PPN or TPN
5) Ambulate
Large bowel obstruction
-less common than SBO
-Causes:
1) Adenocarcinoma
2) Stricture due to diverticulitis/ ischemia
3) Volvulus
4) IBD, foreign bodies, fecal impaction
Presentation of LBO
-crampy pain
-distension, bloating-> may be dramatic
-constipation/obstipation
-sometimes N/V
-high pitched bowel sounds
LBO labs
-CBC, CMP, LDH
LBO diagnosis
1) Plain films (flat, upright abd): distended colon proximal to obstruction, air in rectum-> ileus or partial SBO, intraluminal air-> ischemia, competent ileocecal valve-> higher chance of perf, loss of haustral markings in volvulus
2) CXR: look for free air under diaphragm
3) Gastrograffin enema: if x-ray unclear, if "birds beak"-> volvulus
4) CT scan: if diagnosis unclear
LBO management
-partial: try conservative
1) IV fluids, NPO
2) Antibiotics
3) decompression if vomiting
4) start bowel cleanse slowly if prep for surgery
5) avoid narcotics and anticholinergics
-pseudo-obstruction-> neostigmine, decompression
-complete: usually laparotomy
Volvulus
-abnormal twisting of part of GI tract which can impair blood flow
Sigmoid volvulus
-majority of LBO in 3rd world
-sigmoid more than cecal
-avg 70yo, institutionalized/ delbilitated pts
-hx of constipation
-neuro & psych meds
-twists around mesentary: 180 degrees-> obstruction, 360 degrees-> ischemia
Presentation of sigmoid volvulus
-slowly progressive abd pain
-N/V, distention, constipation
-pain before vomiting
-pain continuous/severe
Imaging of sigmoid volvulus
-KUB/Upright: U shaped 'bent inner tube' sign
-CT scan: whirl pattern and birds beak
-contrast enema: diagnosis and treatment
Treatment of sigmoid volvulus
-Reduction: a) flex sig-> decompress, de-rotate b) interval surgery to resect and fix colon
Cecal volvulus
-rare, younger pts (33-53 yo)
-presentation: variable, intermittent abd pain to acute abd catastrophe
Imaging of cecal volvulus
-KUB/Upright: comma or coffee bean sign w/ air fluid levels
-CT scan-> diagnostic
-barium enema
Treatment of cecal volvulus
1) R colectomy
2) Cecopexy w/ cecostomy tube
3) Cecostomy tube alone in debilitated
Hemorrhoids
-cluster of veins, arteries, CT
-causes: prolonged sitting, straining, pregnancy, advanced age
-sxs from swelling in tissue: local dermatitis (puritis ani), bleeding-> bright red blood per rectum, on toliet paper, not mixed in (exposure of vasculature), swollen tissue may prolapse
Hemorrhoid diagnosis
-internal hemorrhoids= most common cause of rectal bleeding
-visual inspection, DRE, anoscopy, other endoscopic procedures
-CBC
Internal hemorrhoids
-above dentate line
-may bleed and prolapse
-non-painful
External hemorrhoids
-below dentate line
-do not bleed, may thrombose
-pain, itching, scarring
Classification of hemorrhoids
-slide 68
Hemorrhoid treatment
1) Non-operative symptomatic: office txt, rubber band ligation, grade II and II internal hemorrhoids
2) Surgical hemorrhoidectomy: mixed internal & external, extensive thrombosis & pain, persistent bleeding
Perianal infections
-obstruction of perianal crypt glands-> stasis-> bacterial infection
-common from E. coli, bacterioides
-mostly perianal
-causes rectal pain, fullness
-diagnosis: DRE, rarely CT/MRI
Anorectal abscess
-severe, sharp anal pain
-palpable, tender, fluctuant mass
Anorectal abscess treatment
-surgical drainage
-broad spectrum antibiotics
-wound care
-if shallow-> drain in office, some require drain placement
-commonly associated w/ fistula
Fistula in ano (anal fistula)
-abnormal communication btwn anal canal and perianal skin
-50% chance after abscess, Crohn's, diverticulitis
-presentation: chronic drainage of pus, stool from it
-management: fistulotomy, or placement of Seton
Diagnosis of fistula
1) exam under anesthesia-> cord-like tract on DRE
2) MRI for complex/ recurrent
3) Colonoscopy if concern for IBD
Anal fissures
-linear tears in lining of anal canal below dentate line
-causes: trauma from foreign body or very hard BM
-tear-> spasm in muscle-> decreased blood flow and poor healing
-commonly on posterior wall
-presentation: severe rectal pain w/ BM, rectal bleeding
-diagnosis: feel on DRE, if unsure-> flex sig/colonoscopy
Management of anal fissures
-aim for soft, formed BM
-Sitz baths
-Nitroglycerin ointment
-Botox
-if not healed in 3-4 wks then surgery
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