Malabsorption syndrome
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Transcript Malabsorption syndrome
Malabsorption
syndrome
By:
Dr. Elias S.
Dr. Maruf A
Malabsorption
Impaired absorption of one or more
dietary nutrients
Dietary nutrient absorption –in small b.
Ca., iron, folic acid – absorbed in proximal SB
Cobalamine, bile acid – in the ileum
Glucose, a.a., lipids – throughout the SB
Malabsorption could be:
A pathophysiologic state with multiple
etiologies/varied clinical manifestations
Primary (congenital defects)
Secondary (acquired defects)
Clinical Sx usually due to:
Malabsorption of fat &/or carbohydrate
(with water & electrolyte Mal.)
Steatorrhea main feature in most cases
Nutrient
malabsorption
Intestinal
secretion
Diarrhea
Steatorrhea
Watery D.
Inflammatory D.
Inflammation
mechanisms
1.
Luminal phase (processing defect)
2.
Mucosal phase
3.
Digestive enzyme deficiency / inactivation
bile salt synthesis; Excretion; loss;
bile salt de-conjugation
gastric acid; intrinsic factor (p. anemia)
Bacterial consumption of nutrients
Epithelial transport defect – inflammations
infections
Brush border hydrolysis defect
congenital/acquired disacharidase deficiency
Post-absorptive phase
Enterocyte processing – Abetalipoproteinemia
Lymphocytic obstruction – intestinal
lymphangectasia
causes
Exocrine pancreatic insufficiency
ch. Pancreatitis
pancreatic CA
cystic fibrosis
Inactivation of pancreatic
lipase – Gastrinoma(ZES)
drugs (orlistat)
bile acid (impaired
micelle formation)
parenchymal liver D.
cholestatic liver D.
Bacterial overgrowth
Anatomic stasis
(blind loop,stricture,fistula)
Functional stasis
(DM, scleroderma)
Interrupted interohepatic
circulation of bile acid
(ileal resection, crohn’s D.)
Drugs(bind or precipitate bile salt)
neomycin, chlestyramine
Impaired mucosal absorbtion/
mucosal loss or defect
intestinal resection or bypass
inflammation/infiltration/infect.
(celiac sprue, tropical sprue,
whippl’s disease, lymphoma,
mastocytosis, eosinophilic e.,
scleroderma, crohn’s D., …)
Impaired nutrient transport
lymphatic obstruction
(lymphoma, lymphangectasia)
CHF
Genetic disorders
disacharidase defficiency
Agamaglobulinemia
Abetalipoprotinemia
Endocrine/Metabolic disorders
DM
Hyperthyroidism
adrenal insufficiency
carcinoid syndrome
Clinical features
Depend on the cause and severity
Glabal
Diffuse mucosal
involvement
Impaired absorption of
all nutrients
Classic manifestation
Diarrhea(steatorrhea)
weight loss
Majority – sub clinical
E.g.. Celiac disease
Partial (isolated)
2° to diseases that
interfere with
absorption of specific
nutrients
E.g.Pernicious Anemia
Lactase deficiency
Signs & symptoms
Calori
Weight loss with normal appetite
Fat
Pale,voluminous,greasy offensive diarrhea
Protein
Edema, muscle atrophy, amenorrhea
carbohydrate
Abdominal bloating, flatus, w. diarrhea
B12
Macrocytic anemia
Subacut combined degeneration of sp.cord
Folic acid
Macrocytic anemia
Vit B (general)
Cheliosis, glossitis,A.stomatitis, Acrodermatitis
Iron
Microcytic anemia
Ca & Vit D
Osteomalacea (bone pain,pathologic#), Tetany
Vit A
Follicular hyperkeratosis, Night blindness
VIt K
Bleeding diathesis, Hematoma
Clinical Evaluation
In 75-80% of cases
• Dx by expert Hx & P/E + focused lab tests
25% - need extensive study/ Hospitalization
Hx: • Diarrhea- duration, consistency, frequency
stool characteristics, Volume
time of occurrence, association
with diet etc….
• Bloating,borborigmi, flatus
• Abdominal pain
• Sxs of extra intestinal manifestation (joint pain, mouth ulcer..)
• Previous abd. Surgery
• medication
• Alcohol intake
• Recurrent PUD
• DM , CLD
• Falmily Hx – celiac disease, crohn’s D.)
• Risk factors – HIV infection
P/E – thorough examination
Look for
signs of specific nutrient Malabsorption
extraintestinal signs
Lab.
CBC, PT, serum protein, ALP
Checks for depletion of iron,folate, B12, Vit D, Vit K)
RFT,electrolytes
Stool exam
Additional tests:
Serum carotene, cholesterol, albumin, iron, folate
cobalamine
Tests for steatorrhea
Quantitative test
72hr stool fat collection – gold standard
• > 6gm/day – pathologic
• P’ts with steatorrhea - >20gm/day
• Modest elevation in diarrheal disease
(may not necessarily indicate Malabsorption)
Qualitative tests
Sudan lll stain
• Detect clinically significant steatorrhea in
>90% of cases
Acid steatocrit – a gravimetric assay
• Sensitivity – 100%, specificity – 95% , PPV – 90%
NIRA (near infra reflectance analysis)
• Equally accurate with 72hr stool fat test
• Allows simultaneous measurement of fecal fat, nitrogen,
CHO
Schilling test
To determine the cause of cobalamine(B12)
malabsorbtio
Helps to asses the integrity of gastric, pancreatic and
ileal functions.
• Abnormal cobalamine absorbtion in:
pernicious anemia, ch. Pancreatitis, Achlorohydria, Bacterial
overgrowth, ileal dysfunction
The test
• Administering 58Co-labeled cobalamine p.o.
Cobalamine 1mg i.m. 1hr after ingestion to saturate hepatic
binding sites
• Collecting urine for 24 hr
(dependant on normal renal & bladder function)
• Abnormal - <10% excretion in 24 hrs
Schilling test cont….
58CoCbl
Pernicious
Anemia
Chronic
Pancreatitis
Bacterial
overgrowth
Ileal
disease
With
With
5 Days
Intrinsic pancreatic Of Ab
factor
enzyme
N
N
N
D-xylose test
D-xylose
A Pentose monosacharide absorbed
exclusively at the proximal SB
Used to asses proximal SB mucosal function
The test
After overnight fast, 25gm D-xylose p.o.
Urine collected for next 5 hrs
Abnormal test - <4.5 gm excretion
show duodenal / jejunal mucosal D.
False +ve results: Renal dysfunction
Inadequate urine sample
Impaired gastric empyting, ascitis
Drugs(ASA,indometacin, Neomycin)
Othe tests for carbohydrate malabsorbtion
Lactose tolerance test
• P.o. 50gm lactose
• Bloood glucose at 0,60,120 min.
• BG <20mg/l + dev’t of Sxs – diagnostic
Breath tests (hydrogen,4Co2,13Co2)
Test for bacterial overgrowth
Tests for pancreatic insufficiency
Quantitative bacterial count from aspirated
SB. Normal count: < 10 /ml (jejunum)
> 10 /ml (ileum)
Stimulation of pancreas through adm. Of a meal
or hormonal secretagogues , then analysis of duodenal
fluid
Indirect tests – schilling test
Tests for protein malabsorption
Enteral protein loss measuring alpha-1 antitirypsin clearance
Endoscopy
Gross morphology – gives diagnostic clue
Cobblestone appearance – crhon’s D.
Reduced duodenal folds and scallopng
of duodenal mucosa – celiac disease
• Use of vital dyes to identify villous atrophy
Biopsy – to establish Dx
Lesions seen – classifid in to three
For p’ts with documented steatorrhea
or ch. Diarrhea
Diffuse,specific e.g. whippl’s Disease
Patchy, specific – crohn’s D., lymphoma
infectious causes
Diffuse,non-specific – celiac sprue, Tropical sprue
autoimmune enteropathy
Suspected distal pathology - push enteroscopy
wireless capsule endoscopy
Barium studies
Important
information about the gross
anatomy and morphology of SB
Upper GI series with SB follow through
Enteroclysis
• double contrast study by passing a tube into
proximal SB and injecting barium+ methylcellulose
Normal
study doesn’t exclude SB disease