Download Pathogenesis

Approach to the patient with diarrhea
วัตถุประสงค์
1. ทราบ Definition ของ Diarrhea
2. ทราบ กลไกการเกิด Diarrhea
3. เรียนรู้ แนวทางการวินิจฉัยและแยกโรคของภาวะ Diarrhea
4. เรียนรู้ แนวทางการวางแผนการรักษา
Definition of Diarrhea
Pathophysiology :- Stool weight > 200 g/day
(infant stool weight > 10 g/kg/day)
Clinical : Frequency , Liquidity,
Changing character
Form
water
mucous - bloody
Frequency of bowel movement in general population
Mean number of bowel movement /day
Daily intake and endogenous secretion and absorption
Oral intake 2000
Salivary 1500
Glands
Stomach 2500
Bile 500
Net balance 2000-200=1800
Endogenous secretions 7000 ml
Pancreas 1500
Intestine 1000
9000
- 8800
Stool
200
% absorbed 8800/9000=98%
The amount of fluid absorbed differs throughout the intestine
Duodenum / jejunum
~5.5 L
Intake
2 liter
Ileum
~2L
Colon – Rectum
~ 1.3 L
Stool <200 ml
Mechanism of Diarrhea
1. Osmotic diarrhea
2. Secretory diarrhea
3. Inflammatory diarrhea
4. Abnormal gastrointestinal motility
Osmotic Diarrhea
สาเหตุ
1. Unabsorbable osmotic load
2. Malabsorption or maldigestion
กลไก
1. Unabsorbable solute load ---> more fluid
transport to lumen
Osmotic Diarrhea
Raised CI Secretion
Clinical approach to diarrhea
Diarrhea
Acute
Pseudodiarrhea
Chronic
Acute Diarrhea
Infectious
Non infectious
Non infectious acute diarrhea
 Drug induced
 Diet
 Poisoning
Acute Infective Diarrhea
Clinical Evaluation
• Severity of illness
• Underlying disease
Clinical setting
Diagnosis + treatment
Special
Consideration
and management
Parasite
Viruses
Bacteria
Parasites
Enteroadherant E.coli Giardia Cryptosporidia
Bacteria
Helminths
Etiology of infectious diarrhea
• Bacterial
•
•
•
•
•
•
•
Shigella Sp.
Aeromonas Shigelloides
Salmonella Sp.
Vibrio Sp.
Compylobactor Sp.
Clostridium difficile
E.coli (ETEC, EPEC, EIEC, EAEC and EHEC)
• Viral
•
•
•
•
•
Norwalk
Rotavirus
Enteric adenovirus
Cytomegalovirus
Herpes simple virus
• Fungal
• Candida Sp.
• Histoplasma Sp.
• Parasite
•
•
•
•
•
Entamoeba histolytica
Giardia lamblia
Strongyloides
Cryptosporidium
Cyclospora Cayetanensis
Severity of Diarrhea
• Sunken eyeballs
• Poor skin turgor
• Orthostatic hypotension
• Tachycardia
• Oliguria or Anuria
• Alteration of consciousness
Underlying diseases
• AIDS
• Hyperthyroidism
History of Diet
ชนิดของอาหาร
เห็ด
อาหารกระป๋อง
นม
ขนมจีน, แป้งหมัก , ข้ าวผัด
อาหารทะเล
สาเหตุของ diarrhea
Amanita phelloides
Botulism
Lactose deficiency
Samonella
Campylobacter
Bacillus cereus
Vibrio cholerae
Vibiro pararhemolyticus
Vibrio non-O-group I
Norwalk virus
History of Diet
ชนิดของอาหาร
เนื้อไก่ และเครื่ องในสั ตว์
ไข่ ดบิ
นา้ ไม่ สะอาด
ผักและผลไม้ ไม่ สะอาด
เนื้อ, หมู
นา้ แข็ง
สาเหตุของ diarrhea
Samonella , Campylobacter
Salmonella , S aureus
Giardia , Aeromonas
Shigilla , Salmonella
E histolytica
E coli (EHEC)
V. cholera , E coli
Norwalk Virus
ประวัติการกินยา
ยา
•
•
•
•
•
Antacid
Lactose containing drugs
Cancer chemotherapy
Neomycin
Cadiovascular drugs : digitalis ,
quinidine , ganglionic - blocking agent
• Antibiotics
•
•
•
•
•
สาเหตุของ diarrhea
Magnesium induce osmotic diarrhea
Osmotic diarrhea
Mucosal Injury
Malabsorption
Increase motility
• Antibiotic associated enterocolitis
(Clostridium difficile)
Clinical Setting
Food poisoning
Fever
Incubation
Peroid
Mucous-bloody stool
Nausea vomiting
Tenesmus
Voluminous stool
Etiology
Water Diarrhea
(entero/neuro
(non-Invasive
toxin producing)
Organism)
Rare
< 6 hours
Non
++
+
Staphylococcus
aureus, C.perfringens
B, ceceus
Salmonella
Dysentery
(Invasive organism)
Non or Low Grade
6 hours-3 days
Common
1-3 days
Non
+
++
Common
+
+
+
EPEC, ETEC, EAEC
Aeromonas,
Vibrio Cholerae
Giardia,
Cryptospodium
Salmonella
virus
Shigella
P.shigelloides
EIEC EHEC
Salmonella
Campylobactor
C.difficile,
E.Histolytica
V.Parahemolyticus
Stool Leukocyte
Present stool leukocyte
HSV
CMV
Aeromonas
Campylobacter
EIEC, EHEC
Shigella
Salmonella
V.parahemolyticus
Plesiomenas Shigiloides
E.Histolytica
Microsporidium
Strongyloides
Absent stool leukocyte
Adenovirus
Norwalk virus
Rotavirus
Bacillus cereus
Staphylococcus aureus
ETEC, EPEC, EAEC
Giardia lamblia
Cryptosporidium
V. cholerae
Cyclospora sp.
Treatment
1. Supportive
2. Symptomatic
3. Specific
Antimicrobial treatment
• Fecal WBC
• Severe volume depletion
• Community out break
• Impaired host
การรักษา
เชื้อ
Shigella sp.
Areomonas sp.
Drug of choice
Norfloxacin , ofloxacin
Amlnoglycoside
Ceftriaxone
Campylobacter
Erythromycin
Norfloxacin
Clostridium difficile
Metronidazole
Vancomycin
Vibrio cholerae
Tetracycline
E. histolytica
Metronidazole
Giardia lamblia
Metronidazole
Strongyloides
Thiabendazole
Alternative
Ciprofloxacin, ceftriaxone
TMP/SMX, loramphenical
Ciprofloxacin
Bacitacin
Doxycycline , TMP/SMX
Emitine
Quinacrine hydrochloride
Albendazole
Chronic Diarrhea
Functional
HIV
Organic
Non-HIV
Causes of chronic diarrhea in Thai-AIDS
29/45
Found causative organism
Cryptosporidium
TB
Salmomella spp.
CMV
MAC
Strongyloidiasis
Giardiasis
Cryptococcus
Histoplasma carsulatum
Campylobacter
Cyclospora
%
20
17.8
15.5
11.1
6.6
4.4
4.4
2.2
2.2
2.2
2.2
Manatsathit S. et al. J Gastroenterol.1996;31(4):533-7.
Chronic organic diarrhea (Non HIV)
Inflammatory
Malabsorption
Secretory
Chronic Inflammatory Diarrhea
• Infection
• Inflammatory bowel
• Radiation
• Ischemic
Malabsorption syndrome
• Diarrhea
• Malnutrition
Intestinal epithelial cells are continually renewed
Villus
Region
Cell death
And sloughing
Turn over time ~ 48 – 72hr
Crypt
Region
Diving cells
Paneth cells
Normally : # Cells entering villus = # Cells dying
The intestine has a very large surface area
for absorption
Type of surface
Amplification
factor
Surface area
(cm2)
Mucosal cylinder
1
3,300
Fold of Kerkring
3
10,000
Villi
10
100,000
Microvilli
20
2,000,000
Malabsorption syndrome
• Strongyloidiasis
• Giardiasis
• Capillariasis
• Lymphoma
Chronic secretory diarrhea
• Vipoma
• Carcinoid syndrome
• ZE syndrome
Constipation
วัตถุประสงค์
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•
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ทราบ Definition
รู้กลไกการเกิด Constipation
ทราบสาเหตุ
เรียนรู้แนวทางการวินิจฉัยและแยกโรค
เรียนรู้แนวทางการวางแผนการรักษา
Definition
Acute
Chronic
Patient review
Clinical review
Rome II Criteria for chronic constipation
(At least 2 of following)
• Fever than 3 bowel movement/week
• Hard stool in more than 25% of BM
• A sense incomplete evaluation in more than 25% of BM
• Excessive staining in more than 25% of BM
• The necessity of digital manipulation to facilitate
evaluation
• Any 12 week period in the least 12 months
Pathogenesis
Drugs
(opiates, phenothiazines)
Obstruction Pseudo-obstruction
Cause of constipation
Extrinsic
Structural
Systemic
Neurological
Drugs
Extrinsic
• Inadequate dietary fiber, fluid
• Ignoring urge to defecate
Structural
• Colorectal : neoplasms, stricture,
ischemia , volvulus, diverticular
disease
• Anorectal : inflammations,
prolapse, rectocele,fissure, stricture
Systemic
• Hypokalemia
• Hypercalcemia
• Hyperparathyroidism
• Hypothyroidism
• Hyperthyroidism
• Diabetes mellitus
Neurological
• CNS : Parkinson’s disease, multiple
sclerosis, trauma, ischemia, tumor
• Sacral nerves : trauma, tumor
• Autonomic neuropathy
• Aganglionosis (Hirschsprung’s disease)
Drugs
• Analgesics
• Opiates, non-steroidal antiinflammatory
• Anticholinergics
• Atropine agent,
antidepressants, neuroleptics
Drugs
• Metal ions
• Aluminum (antacids, sucralfate),
barium sulfate , bismuth, calcium,
iron, heavy metals (arsenic, mercury)
• Resins
• Cholestyramine, polystyrene
Diagnosis and differential
• History taking
• Physical examination
• Diagnostic techniques
History taking
• How many stools per week?
• Chronic constipation or not?
• Is there concomitant abdominal pain?
• Dietary history
• Lifestyle
• Use of laxative
• Use of other drugs
Physical examination
• Percussion (check for gas)
• Palpable feces (‘loaded colon’)
Rectal palpation
• Consistency / impaction
• Presence of non fecal masses pr
abnormalities (tumor, hemorrhoid, fissures,
fistulas, prolapse, neoplasms)
• Presence of blood
• Sphincter tone
Diagnostic techniques
• Stool analysis (assess seriousness)
• weighing 3 days ; < 100 g average means constipation
• Abdominal Xray (assess seriousness)
• Radiological or Endoscopic investigation (to
assess/exclude obstructions) :
– megacolon
– redundant sigmoid colon
– pattern of haustral folds
» IBS patients ---> normal length haustral colon
» Colon inertia ---> longer length less haustral colon
Major Alarm symptoms especially
in patients > 50 yr
• New onset constipation
• Anemia
• Weight loss
• Anal blood loss
• Positive occult blood test
• Sudden change in defecation pattern and
appearance of stool
Stepped Treatment of Constipation
change lifestyle and diet
Stop medications which cause constipation
Bulk-forming agent
Osmotic laxatives
Pelvic floor
physiotherapy
Contact laxatives
Enema
Prokinetics
Laxatives
• Bulk laxative
• Psyllium
• Polycarbophil
• Methylcellulose
• Lubricating agents
• Mineral oil
Laxatives
• Osmotic agents
• Magnesium and phosphate salts
• Lactulose
• Sorbitol
• Polyethylene glycol
• Glycerin suppositories
Laxatives
• Stimulant laxatives
• Surface acting agents
– Ducusate
– Bile acids
• Diphenymethane derivates
– Phenolphtalein
– Bisacodyl
– Sodium picosulfate
• Ricinoleic acid
• Anthraquinones
– Senna
– Cascara sagrada
– Aloe
– Rhubarb