Lower GI Disorders Flashcards
Nausea, crampy abdominal pain, abdominal distension, no BM, mildly tender abdomen w/o rebound, elevated WBC count
Dx = SBO; workup req’s obstructive series which demonstrates multiple air fluid levels in small bowel w/o air in the colon/rectum
fluid/electrolyte status of pt w/SBO
Dehydration d/t vomiting and poor PO intake. Contraction (water loss in vomitus) alkalosis (d/t vomiting up H+) with HYPOchloremic (loss in vomitus) HYPOkalemia (kidney retains Na+ and H+ to compensate for loss in vomit and in turn results in loss of K+ into urine)
correction of contraction alkalosis
Rehydration w/IV fluids containing Na+ and K+
Mgmt for pt w/SBO
- NG drain
- IV fluids
- Serial PE, Labs, abdominal Xray to monitor for leukocytosis, fever, acidosis, localized tenderness
Proximal vs. distal GI obstructions
Proximal obstructions have less abdominal distension on PE
Causes of abdominal adhesions
- Prior surgery
- Hernia
- SB tumors
- Metastatic tumors to the bowel
- Inflammatory processes
Pt passes flatus but not stool
Partial small bowel obstruction; more likely to resolve on its own w/o ischemia or perforation
DDx for small amount of diarrhea
- partial small bowel obstruction
- Gastroenteritis
- Fecal impaction
- Severe constipation
- Inguinal hernia
- Metastatic melanoma to the intestines (most common tumor to met to intestine)
- Recurrent ovarian CA (peritoneal studding causes obstruction
- Metastatic breast cancer
Localized tenderness + sx of bowel obstruction +/- marked leukocytosis
Requires surgical exploration DDx: 1. Closed loop obstruction 2. Perforation 3. ischemia 4. Abscess
Metabolic acidosis + sx of bowel obstruction
Suspect ischemic or necrotic bowel
Workup: urgent exploration vs. mesenteric arteriography to evaluate bloodflow
High fever + sx of bowel obstruction
suspect bowel perforation or ischmia
Recurrence of abdominal distension and nausea after previous improvement on NG tube
If pt fails nonoperative mgmt then the next step would be ex-lap. Most likely finding = adhesive band affecting single/multiple bowel segments. Plan: lysis of adhesions to free up all of involved bowel
Closed loop obstruction on abd Xray
Adhesive band occluding both the inlet AND outlet of a loop of bowel resulting in accumulation of secretions and air in the loop and distention.
Complications: blood flow obstruction d/t twisting of the blood supply or adhesive band obstructing the blood supply
What is a “second look” operation?
Re-exploration of bowel 24-hrs after detecting edematous bowel from twisting
Crampy abd pain + free air in peritoneum
- Ischemic perforation
2. Perforation d/t overdistention of bowel
Small bowel obstruction + inguinal hernia
Suspect incarcerated inguinal hernia d/t SBO.
Treatment:
1. inguinal approach w/exploration and hernia reduction with repair
2. Abdominal approach is better for ill-appearing patients b/c it allows for thorough inspection of the entire bowel w/possible resection/reanastamosis
Unplanned enterotomy (perforation of bowel during surgery)
- Small holes may be repaired via suture
2. Large or multiple holes require bowel resection
Complications of enterotomy
Small bowel fistula
Diseases mimicking SBO
- HF
- Sepsis
- COPD
Study to r/o SBO
- Upper GI series w/small bowel follow through w/barium
N/V, severe abd pain, low grade fever, elevated WBC count
Suspect ischemic bowel
- Proceed to OR if suspect necrotic bowel
- Further eval and tx prior to surgery (hydration, sigmoidoscopy, mesenteric angiogram)
If pain worsens then consider bowel necrosis and proceed directly to the OR
Same as above but with LOW WBC count
Elderly pts may respond to overwhelming sepsis w/leukopenia
Causes for polycythemia? Risks a/w polycythemia? Tx?
- Dehydration
- Polycythemia vera
- COPD or other hypoxemic states
Complications = hypercoagulable state and may cause stasis/low flow/thrombosis in vascular beds
Tx = phlebotomy + hydration
Causes of bloody diarrhea? Workup?
Dx = colonic ischemia w/necrosis of the mucosa and subsequent sloughing
Sigmoidoscopy to assess colon. Mucosal ischemia tx includes optimizing hemodynamics, ABx, and observation. Full thickness neecrosis requires exploration +/- resection
Necrosis extending from ligament of Treitz to transverse colon
Most likely hopeless situation. Surgical resection + reanastamosis in younger pts is ok. most likely results in short bowel syndrome.
Necrosis of 2ft of jejunum and ischmia of adjacent bowel
- Resection + reanastamosis
- Second look
- Ileostomy (avoids risk of anastomotic breakdown)
Ischemia w/o necrosis d/t acute occlusion of the SMA
SMA should be exposed and the occlusion removed or bypassed
Crampy abd pain, N/V, hx of Crohn’s of terminal ileum s/p steroid infusion 6mo ago, now presenting w/SBO
SBO 2/2 stricture of the involved bowel w/Crohn’s disease
Workup for Crohn’s diasease
- CT abdomen demonstrates stenotic bowel in the terminal ileum may reveal stenotic bowel, perforation, abscess/fistula formation
Tx for Crohn’s stricture
- TPN
- Bowel rest
- Observation
If Crohn’s stricture/SBO does not resolve or recurs then surgery is indicated
- Relieve the obstruction by bowel resection
- Resect strictures and involved bowel back to grossly normal appearing bowel
- Stricturoplasties (cut strictures axiailly and repair them transversely to dilate the lumen
Complications of surgical intervention for Crohn’s
- Reoperation in the future
- B12 deficiency
- Impaired reabsorption of bile salts
- Malabsorption d/t deplection of bile salt pool
- Diarrhea d/t inability to digest fats.
Perianal dz in Crohn’s
- Surgery indicated to drain perirectal abscesses
- Mgmt of superficial fistulas
- Seton insertion - plastic tubes that facilitate fistula closure
- Metronidazole
Crohn’s dz in colon vs. Crohn’s dz in small bowel
Rectal involvement is NOT favorable. If dz is limited to colon then 5-ASA+ steroids. If surgical complications evolve then subtotal colectomy and ileostomy may be performed if rectum is involved. If dz is limited to small bowel then the 5-ASA is not effective. If rectum spared then a reanastamosis may be performed to the sigmoid or rectum
Screening for CRC in pts with UC
- Pancolitis = colonoscopy q1-2yrs after 8yrs of dz
- Left colitis = colonoscopy q1-2yrs after 10yrs of dz
- Suspicious lesions (strictures, polypoid lesions, and mucosal plaques) warrant biopsy
- Random biopsy is also reqd b/c CRC doesnt always follow pathway of polyp to CA
- Colectomy + rectum removal in the case of severe dysplasia
Goals of surgical intervention for CRC
- Remove entire colonic and rectal mucosa
- Restore anal continence
- Establish a reservoir function to allow controlled defecation
e. g. total proctocolectomy (removes mucosa i.e. risk of CA) with ileorectal anastamosis
Pt is s/p total proctocolectomy w/ileal pouch anal anastamosis p/w fever, bloody diarrhea, and pain w/defecation
Pouchitis resulting in hemorrhagic mucosa w/edema and small ulcerations. Tx = Metronidazole
Several mo of abd cramps, diarrhea, 5lb weight loss, bloody diarrhea x1day
IBD
Workup: colonoscopy or barium enema. Ulcerative colitis affects only the mucosa, begins in distal colon and rectum and has crypt abscesses and raised ulcerations
Bloody diarrhea, abd pain, distention, fever, tachycardia. Workup for DDx
Suspect Toxic megacolon
Workup:
1) Abdominal obstructive series to r/o perforation
2) Abdominal CT to r/o abscess or perforation
Mgmt of UC/toxic megacolon
1) NG tube
2) NPO
3) TPN
4) IV fluids
5) Broad-spec ABx
6) High dose IV steroids
7) Close observation for worsening s/s with frequent abd examinations and radiographs to r/o toxic megacolon
Free air on upright CXR or air in the wall of the colon
Operate immediately as these are signs of perforation. Perform ileostomy w/Hartmann pouch of the rectum
Pain in middle abdomen–>lower right abdomen. Anorexia. No guarding or rebound tenderness in RLQ
Dx: Appendicitis Workup: 1) Rectal exam to r/o retroceal appendicitis 2) Pelvic exam to r/o ovarian dz and PID Mgmt: 1) NPO 2) Hydration 3) Observation + serial exams 4) Repeat CBC 5) AVOID PAIN MEDS B/C THEY MASK SX
abdominal pain, anorexia, no guarding/rebound, dysuria and urinary WBC >10000/hpf
UTI may also occur with appendicitis d/t appendiceal abscess in continuity with the bladder
same as above but with only few WBC detected and only minimal dysuria
Local inflammatory processs results in inflammation of urinary tract d/t local inflammatory process
If a pt has suspected IBD d/t significant FHx
consider CT imaging before exploration. CT may show thickened loop of bowel or enlarged nodes in the terminal ileum in the case of IBD. But remember that appendicitis may still occur in pt with IBD