Transcript Short Bowel Syndrome

Short Bowel Syndrome
Ricardo A. Caicedo, M.D.
Pediatric Gastroenterology
Definitions
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Short bowel syndrome (SBS)
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Functional impairment resulting from critical
reduction in intestinal length
Includes malnutrition, chronic diarrhea,
malabsorption, growth failure
The most common cause of…
Intestinal failure
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Severely compromised intestinal function of any
etiology (irrespective of bowel length)
Total parenteral nutrition (TPN)-dependent
Etiology: Neonates
Congenital
NEC
- Gastroschisis
- Omphalocele
- SB atresias
- Volvulus
-Malrotation
-Other
- Thrombosis
- Aganglionosis
About 20 % of infants with NEC requiring resection develop SBS
Etiology: Children/Adolescents
Volvulus
 Trauma
 Intra-abdominal cancer
 Vascular anomalies
 Radiation enteropathy
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Overall Incidence
1:500,000
Prognostic Factors
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SB length
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Absorptive function of residual SB
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Proportion of daily calories tolerated enterally
Intestinal adaptation
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Normal FT infant: 200-250 cm
Loss of >70% (residual SB length < 70 cm in infants)
portends SBS
Compensatory events stimulated by massive bowel resection
Anatomy of resection
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Loss of segment-specific functions
Loss of ileocecal valve
Anatomic Considerations
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Loss of segment-specific functions
Jejunum: primary site of digestion and
absorption
 Ileum: B12 and bile acid absorption
 Colon: water absorption and adjunctive
carbohydrate absorption
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Ileo-cecal valve
Regulation of intestinal transit
 Prevention of bacterial reflux into SB
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Management: Postoperative Period
Maintenance of fluid/electrolyte balance
 Maintenance TPN
 Separate IVF for ostomy output
replacement
 H2-blocker to tx gastric hypersecretion
 Await resolution of postoperative ileus
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Enteral Feeding
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Initiated when postop. Ileus resolved, UGI tract
decompressed, and F/E/N status stable
 Advancement of EN and reduction/elimination
of PN is the goal
Promotes intestinal adaptation
 Follow hydration status, stool output, body growth,
labs (albumin, prealbumin, Hb, BUN)
Continuous tube feeds: decrease SB osmotic load and
absorptive workload per unit of time
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Enteral Feeding Composition
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Protein
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Breast milk: promotes adaptation
Hydrolysate (semi-elemental): peptides more easily assimilated
in short gut
Amino acid (elemental): prevention of milk protein
hypersensitivity
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Fats
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MCT do not required bile acids/micelle formation for absorption
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Higher osmolarity
Excess of MCT can lead to EFA deficiency
Carbohydrate
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CHO malabsorption is the rate-limiting factor in advancing EN
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Glucose polymers digested more efficiently than lactose
Start with dilute formula
increasing in volume before increasing energy density OR
Increasing in concentration before increasing rate
Monitor stool output, pH, reducing substances
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Advancement of EN
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Supplements
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Vitamins ADEK, B12
Electrolytes: Na/K citrate, Ca, Mg
Elements: Fe, Zn
Cycle/window and wean TPN
 Increase EN at avg. rate of 0.5-1.0 cal/kg q 1-3
days
 Non-nutritive sucking and PO feeding to
prevent oral feeding aversion
 Intolerance of EN but stable: home TPN
Predicting Ability to Wean TPN
Length of residual SB
 Percent daily enteral intake
 Earlier restoration of intestinal continuity
 Fewer complications
 Biomarkers: experimental stage
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Urine 3-0-methylglucose after PO feeding (rat model)
 Plasma citrulline levels (adult SBS pts)
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< 20 umol/L predict permanent intestinal failure
Complications
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TPN-related
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CVL-related
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Cholestasis/hepatopathy
Calcium-bilirubinate gallstone disease
Infection- bacterial or fungal sepsis
Thrombus/thromboembolism
SB bacterial overgrowth
 Nutrient deficiencies
 Enterocolitis
 Mechanical or pseudo-obstruction (dysmotility)
 Pancreatitis
 Nephrolithiasis (oxalate stones)
Prevention of TPN Liver Disease
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Reduce TPN/advance EN
 Cycle TPN (run < 18 hrs/d)
 Monitor TPN composition
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Glucose infusion rate < 8-12 mg/kg/min
Keep AA at 2.5 g/kg/d
Keep lipids at < 40% of total caloric intake
Reduce trace elements (Mn, Cu) to 25% RDA once
cholestasis develops
Manage CVL infection and SBBO
 Start UDCA at 15-30 mg/kg/d
SB Bacterial Overgrowth
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Factors
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Symptoms
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Feeding intolerance, abd. distention, weight loss, blood in
stools
D-lactic acidemia: lethargy, ataxia, WAGMA
Diagnosis
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Dysmotility/poor peristalsis leading to stasis of enteral contents
Loss of ICV
Duodenal fluid aspirate and culture (> 105 col/ml)
Breath hydrogen test
Often made on clinical grounds
Treatment
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Empiric antibiotics (metronidazole, TMP-SMX, PO gentamicin, amoxclavulonate, rifaximin)
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Adjunctive probiotics: little evidence, and a safety concern in SBS
pts esp. those with CVL
Medical Therapies
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Anti-motility agents
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Loperamide, diphenoxylate/atropine
Slow transit time
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Bile acid binder (cholestyramine)
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Improve fluid absorption and reduce fecal fluid loss
Prevents bile acid malabsorption and bile acid-induced
secretory diarrhea
Octreotide: reduces output from proximal enterostomies
Glutamine/GH
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Mostly theoretical/animal or transient benefit
GLP-2: may stimulate mucosal growth and reduce
secretions; still experimental
Surgical Interventions
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Longitudinal tapering
 Bianchi lengthening
operation
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Doubles length,
reduces diameter
by 0.5
preserves effective
surface area
Serial Transverse Enteroplasty (STEP)
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Creates a maze-like
tunnel within dilated
segment
 Kim HB et al, J.
Pediatr Surg. 2003;
38:881-5.
SB Transplantation
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Indications (Am. Soc.
Transplantation, 2001)
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Progressive/irreversible TPN liver
disease (~ 4% of infants w/SBS)
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Cholestasis beyond 3-4 mos of age
Features of PORTAL HTN
Impaired synthetic function
(albumin, INR)
Recurrent sepsis
Threatened loss of central venous
access
Contraindications
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Absolute: AIDS, overwhelming
sepsis
Relative: weight < 5 kg, multiple
previous abdominal operations
Survival
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Overall: 80-94%
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Mortality higher in patients with NEC
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Very long term (up to 25 y) TPN: 94% survival
Transplantation
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Mortality is center-specific
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Largest experience: U. Pittsburgh (Reyes J, Semin Pediatr Surg 2001)
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1-yr survival rate: 70%
3-yr, all ages combined: 55%
Mortality greater in
Patients under 2 y of age
Combined SB-liver tx
Higher risk of PTLD in SB transplantation
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