《儿科学教学》16、infantile diarrhea（上）

1、编辑pptInfantile DiarrheaLi zhongyueDep. Gastroenterology Childrens Hospital , CQMU编辑pptDep. GastroenterologyChildrens Hospital, CQMU编辑pptContent Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management & prevention Fluid therapy Diarrhea编辑p

2、ptContent Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management & prevention Fluid therapy Diarrhea编辑pptDiarrhea-definition Diarrhea is defined as an increase in the Fluidity, Volume, and Frequency of stools. Volume 10 ml/kg/d in childr

3、en or 200g/day in adolescents Fluidity Decrease in consistency (loose or liquid) Frequency Bowel movements3 per 24 hours 编辑pptConstipationDiarrhea编辑ppt编辑pptContent Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management & prevention Fluid

4、 therapy Diarrhea编辑pptEpidemiology High incidence and mortality European 0.5-1.9 episodes per person per year编辑ppt Consume large amounts of health care costs USA: 1-2 episodes/child/year 1.5 Million medical consultations 160,000 ER visits 220,000 hospitalizations (mean hospital stay 3.4 days) $ 1.8

5、Billion per year of medical costs Mortality rates: 32.2 deaths/100,000 live born in Afro-Americans (8.2 in whites)编辑ppt Dehydration Death Malnutrition Growth retardation Impaired mental development Consequences of diarrhea in children编辑ppt编辑ppt编辑ppt leading causes of death in children in developing

6、countries 15%编辑pptMortality from diarrhea diseases among children in developing countriesThe mortality of diarrhea is decline:Development of economyProgress of Medicine Improvement of medical conditionsORS useBut 编辑pptPredisposing factor Infant digestive system is not well developed, and the functio

7、n is immature: Lack of gastric acid secretion,-Lower enzyme activity,-Rapid gastric emptying (infection & indigestion). Water metabolism rapidly, the water tolerance is poor, once the water loss prone to humoral disorder. The functions of nerve system, endocrine, circulation, liver, kidney are i

8、nmature, prone to gastrointestinal dysfunction. More nutrition demand Because children are growing rapidly, they need more nutrition to meet their rapid growth the burden of digestive system is heavier. 编辑ppt Weakness of defense system Lack of gastric acid secretion, -rapid gastric emptying, -lower

9、enzyme activity.The introgastric pathogenes cannot be killed thoroughly. The levels of serum IgA, IgM and the secretory IgA in intestinal tract are lower, so the immune defense is insufficient. Normal intestinal flora have not well established 编辑ppt编辑ppt编辑ppt编辑ppt Bottle-feeding (or artificial feedi

10、ng) Milk or/and bottle is prone to contaminated with pathogens during handling Milk nutrition damaged Breast milk contains immune components:(sIgA, lactoferrin, lysozyme,etc.)编辑ppt编辑pptE.coli编辑pptEtiology Infective factors (virus,bacteria,fungi,parasites) Noninfective factors Dietary factor Inapprop

11、riate feeding Allergic Diarrhea Disaccharidase Deficiency Climate Symptomatic Diarrhea 编辑pptEtiology Infective factors (virus,bacteria,fungi,parasites) Noninfective factors Dietary factor Inappropriate feeding Allergic Diarrhea Disaccharidase Deficiency Climate Symptomatic Diarrhea 编辑pptEtiology-Inf

12、ective factors Route of transmission: feces-mouth way编辑pptPathogens of infective factors编辑ppt编辑ppt编辑pptEtiology-Infective factorsViruses: The most Common pathogen in children with infected diarrhea. Rotavirus, Astrovirus, Noro virus, Coronavirus, Calicivirus, Enteric adenovirus, echo virus, cosackis

13、 virus, and so on. Usually occurs in the cold season(Autumn, winter). Rotavirus is the most severe enteric pathogen of childhood diarrhea. 编辑ppt编辑pptEtiology-Infective factors Bacteria: The second most common cause in children with infective diarrhea.编辑pptEtiology-Infective factors Fungi: Candida al

14、bicans, aspergillus, mucor编辑pptEtiology-Infective factors Parasites: 编辑pptEtiology-Infective factors The most important infective causes of acute diarrhea in developing countries in children are: Rotavirus Enterotoxigenic Escherichia coli Shigella Campylobacter jejuni Salmonella typhimurium编辑pptEtio

15、logy Infective factors (virus,bacteria,fungi,parasites) Noninfective factors Dietary factor Inappropriate feeding Allergic Diarrhea Disaccharidase Deficiency Climate Symptomatic Diarrhea 编辑pptEtiology-Non-Infective factors Dietary factors Inappropriate feeding (Dietary Diarrhea): Overfeeding Indiges

16、tible diet Sudden change of formula Inappropriate feeding for a milk-fed baby shifting into solid food (too much, too early, too rapid) Disaccharidase Deficiency: Lactose Intolerance Primary disaccharidase deficiency Secondary disaccharidase deficiency Allergic Diarrhea编辑pptAllergic colitis编辑pptEtio

17、logy-Non-Infective factors Climate Seasonal variation affects the digestive function of young children: incidence of diarrhea is highest furing the early rainy season Cold weather causes increasing of enterokinesia Hot weather causes decreasing of digestive enzyme and malfunction of digestive tract.

18、编辑pptEtiology-Non-Infective factors Symptomatic Diarrhea: Diarrhea is only one of the symptoms of primary disease. Problem is not originally located in intestinal tract. Respiratory tract infection,-Otitis media,-Some infectious diseases, etc. Fever, toxin,antibiotics,local stimulate,etc. Symptom al

19、ways mild, and recover with the primary disease getting better. The younger the children, the more chance to get a symptomatic diarrhea accompanied by other diseases. 编辑pptContent Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management &

20、prevention Fluid therapy Diarrhea编辑pptPathogenesis of Diarrhea The basic pathogenesis of diarrhea: Osmotic Diarrhea (Pathogenesis of Viral Diarrhea) Secretory Diarrhea( Pathogenesis of Enterotoxigenic Diarrhea) Invasive diarrhea(Exudative diarrhea, Inflammatory diarrhea) Motility abnormalities编辑pptP

21、athogenesis of Diarrhea The basic pathogenesis of diarrhea: Osmotic Diarrhea (Pathogenesis of Viral Diarrhea) Secretory Diarrhea( Pathogenesis of Enterotoxigenic Diarrhea) Invasive diarrhea(Exudative diarrhea, Inflammatory diarrhea) Motility abnormalities编辑ppt编辑pptOsmotic Diarrhea Pathogens: Virus G

22、iardia EAEC Characteristics: Watery stool Stool WBC(-) Stool RBC(-) Diarrhea improved after fasting编辑pptPathogenesis of Diarrhea The basic pathogenesis of diarrhea: Osmotic Diarrhea (Pathogenesis of Viral Diarrhea) Secretory Diarrhea( Pathogenesis of Enterotoxigenic Diarrhea) Invasive diarrhea(Exuda

23、tive diarrhea, Inflammatory diarrhea) Motility abnormalities编辑ppt编辑pptSecretory Diarrhea Pathogens: Vibrio cholerae (cholera) Enterotoxigenic Escherichia Coli (ETEC) Staphylococcus aureus Clostridium difficile Characteristics: Watery stool Stool WBC(-) Stool RBC(-) Diarrhea without improvement after

24、 fasting编辑pptPathogenesis of Diarrhea The basic pathogenesis of diarrhea: Osmotic Diarrhea (Pathogenesis of Viral Diarrhea) Secretory Diarrhea( Pathogenesis of Enterotoxigenic Diarrhea) Invasive diarrhea(Exudative diarrhea, Inflammatory diarrhea) Motility abnormalities编辑ppt编辑pptInvasive Diarrhea Inv

25、asive organisms: Shigella species EIEC (enteroinvasive E. coli) Campylobacter jejuni Salmonella typhimurium Yersinia enterocolitica Characteristics: Mucopurulent bloody stool Stool WBC (+) Stool RBC (+) Abdominal pain Tenesmus Fever Toxic appearance 编辑ppt编辑ppt编辑pptPathogenesis of Diarrhea Pathogenes

26、is of Dietary DiarrheaInappropriate diet Overfeeding Indigestible diet Sudden change of formula Inappropriate solid food adding(too much, too early or too rapid, and so on.) 编辑ppt编辑ppt Clinical features of Dietary Diarrhea Watery like diarrhea Stool WBC (-) Stool RBC (-) anorexia Abdominal pain Feve

27、r Toxic appearanceDyspepsia编辑pptPathogenesis of Diarrhea The basic pathogenesis of diarrhea: Osmotic diarrhea Secretory diarrhea Exudative diarrhea:Invasive diarrhea, Inflammatory diarrhea Motility abnormalities Diarrhea is not caused by a single mechanism, but occur in a variety of mechanisms.编辑ppt

28、Content Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management & prevention Fluid therapy Diarrhea编辑pptClinical manifestations of diarrhea Common symptoms Classification Water-electrolyte disturbances, acid-base imbalance(see detail in n

29、ext section) Clinical characteristics of diarrhea caused by special pathogen(rotavirus infection)编辑pptClinical manifestations of diarrhea Common symptoms Site of action: small intestine: enterotoxin-producing organisms enteroadhesive organisms large intestine: invasive organisms cytotoxin-producing

30、organisms enteroadhesive organisms编辑ppt Gastrointestinal symptom: Anorexia(Loss of appetite) Nausea Vomit Diarrhea( watery or bloody) with or without abdominal pain编辑ppt Systemic symptom Fever, pale Debilitation/restlessness/irritability Lethargy/depression/indisposition, etc. Water-electrolyte dist

31、urbances,base-acid imbalance.(see detail in next section)编辑pptClinical manifestations of diarrhea Classification编辑pptClinical manifestations of diarrhea Classification编辑pptClinical manifestations of diarrhea Clinical characteristics of diarrhea caused by special pathogen-rotavirus编辑pptRotavirus编辑ppt

32、编辑pptRotavirusVirology:Double-stranded RNA virus Live seven months under normal temperature, acid-resistance, -20 can be long-term preservationVP6, Rotavirus is divided into seven groups: A-G groupsGroup A is the most important parhogen in childhood diarrheaEpidemiology:Peak season: autumn/winter, “

33、Autumn diarrhea”Contagiousness: fece-mouth way or spread by gasoloid. Peak age: 6M2yrs old.编辑ppt编辑ppt编辑ppt编辑pptRotavirus Mechanisms: Pathogenesis of Viral Diarrhea NSP4编辑pptRotavirus编辑pptContent Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Ma

34、nagement & prevention Fluid therapy Diarrhea编辑pptDiagnosis of diarrhea The initial clinical evaluation of the patient should focus on: Assessing the severity of the illness and the need for rehydration Identifying likely causes on the basis of the history and clinical findings 编辑pptPhysical exam

35、inationHistory Assess dehydrationEvaluation of acute diarrhea patient Onset,frequency,quantityCharacter-bile,blood,mucusVomitingPast medical historyUnderlying medical conditionsEpidemiological clues Body weightTemperatureHart rateRespiratory rateBlood pressureGeneral appearance,alertnessPulse and bl

36、ood pressurePosture hypotensionMucosa and tearsSunken eyes,skin turgorCapillary refill,jugular venous pressureSunken fontanelle 编辑ppt Can stool analysis differentiate a Bacterial from a Nonbacterial Agent? Fecal marker? Stool cultures are usually unnecessary for immunocompetent patients who present

37、within 24 hours after the onset of acute, watery diarrhea. Microbiologic investigation is indicated in patients who are dehydrated or febrile or have blood or pus in their stool. How about lab. findings?编辑ppt编辑ppt Electrolytes should be measured: In moderately dehydrated children whose history and p

38、hysical examination findings are inconsistent with a straight diarrheal disease All severely dehydrated children (Va, D). In all children starting intravenous (IV) therapy,and during therapy because hyper- or hyponatremia will alter the rate at which IV rehydration fluids will be given (Va, D). 编辑pp

39、tContent Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management & prevention Fluid therapy Diarrhea编辑pptDo We Know How to Treat It?Diarrhea编辑pptManagement of diarrhea 编辑pptManagement of diarrhea Fluid therapy Diet and Nutrition therapy D

40、rug therapy 编辑ppt编辑ppt编辑ppt Drug therapy Antimicrobial therapy Adsorbents Probiotics Supplemental zinc therapy, multivitamins, and minerals Antiemetics Antidiarrheal treatment Antisecretory agents 编辑ppt编辑ppt编辑ppt编辑ppt编辑pptSupplemental zinc therapy, multivitamins, and minerals For all children with d

41、iarrhea: 20 mg zinc for 14 days(WHO&UNICEF).Antiemetics Suggest that antiemetics should not be routinely used to treat vomiting during AGE in children (II, B). Ondansetron ( 5- hydroxytryptamine serotonin antagonist) Metoclopramide(a dopamine antagonist) 编辑ppt Antidiarrheal treatment Nonspecific

42、 antidiarrheal treatment Antimotility: Antisecretory agents: 编辑ppt编辑ppt编辑pptPrevention Water, sanitation, and hygiene: Safe water Sanitation: houseflies can transfer bacterial pathogens Hygiene: hand washing Safe food: Cooking eliminates most pathogens from foods Exclusive breastfeeding for infants

43、Weaning foods are vehicles of enteric infection To avoid misuse of antibiotics Micronutrient supplementation: depends on the childs overall immunologic and nutritional state further research is needed编辑ppt Vaccines: Salmonella typhi: Shigella organisms: V. cholerae: ETEC vaccines: Rotavirus: RotaTeq

44、 (Merck) Rotarix (GSK) Measles immunization:编辑pptContent Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management & prevention Fluid therapy Diarrhea编辑pptFluid therapy The characteristics of childrens water-electrolytes balance Disturbance

45、s of water and electrolytes Common Solution of fluid Therapy Intravenous infusion编辑pptFliud therapy The characteristics of childrens water-electrolytes balance Volume and distribution of body fluid 编辑ppt编辑ppt Composition of electrolyte in body fluids 编辑ppt编辑ppt The characteristics of water metabolis

46、m in children Large water requirements, high water exchange rate High metabolism,need more water. Insensible loss of water loss (double adults amount). Infants water exchange amount is 1/2 of ECF, the adults is only 1/7. Immature of body fluid regulating function ( concentration-dilution function )编

47、辑ppt编辑ppt编辑ppt编辑ppt Disturbances of water and electrolytes Dehydration Hypokalemia Metabolic acidosis Hypocalcemia Hypomagnesemia编辑ppt Dehydration Assessment of dehydration Mild Moderate Severe The types of dehydration Hypotonic dehydration Isotonic dehydration Hypertonic dehydration编辑ppt编辑ppt编辑ppt编

48、辑ppt编辑pptIsotonicHypertonicHypotonic编辑pptNormalInterstitial fluidIntracellular fluidPlasmaHypotonic dehydrationSodiumwaterOsmotic pressure of ECFICFWater will shift from ECF to ICFICF ECFCell edemacirculatory failure+编辑pptIsotonic dehydrationNormalInterstitial fluidIntracellular fluidPlasmaSodium=wa

49、terOsmotic pressure of ECF=ICFNo water shift between ECF and ICFICF- ECFNormal Cell shapecirculatory failure+编辑pptHypertonic dehydrationNormalInterstitial fluidIntracellular fluidPlasmaSodiumwaterOsmotic pressure of ECFICFWater will shift from ICF to ECFICF ECFCell dehydrationcirculatory failure+编辑p

50、pt Hypokalemia Serum K+ Pathogenesis intake insufficient Loss of kalium from kidneys or gastrointestinal tract Abnormal kalium distribution (K shifts into the cells). alkalosis, insulin therapy、periodic paralysis） Burn, dialysis, etc. 编辑ppt编辑ppt Hypokalemia -Clinical manifestations Nervous system de

51、pressed Muscle Muscular tension decreased，Abdominal distension，Respiratory muscle paralysis. Cardiovascular system Tachycardia, lower heart sound, arrhythmia, Bradycardia，atrioventricular block, Adams-Stokes syndrome, Electrocardiogram shows U wave appearing，UT， flatten T wave. Prolonged Q-T period,

52、depressed S-T Kidney concentrating function decreased, urine volume increased(polyuria)编辑ppt编辑ppt Metabolic acidosis Pathogenesis The lose of large amount of basic substances（from gastrointestinal tract, kidneys） Too much Acid metabolites （because of hungriness, diabetes, renal failure, hypoxia） Too

53、 much acid substance intake （long time to take calcium chloride, ammonium chloride, amino acid. ） 编辑ppt Degrees of acidosis编辑ppt Clinical features: Mild acidosis: symptoms is not obvious, only faster breathing Sereve acidosis : depressed, irritable, lethary, coma, deep and fast breathing, (kussmauls

54、 breathing), breath with ketone smell, red lip nausea and vomiting编辑ppt Hypocalcemia Normal serum Ca2+: 2.22.7mmol/L (911mg/dl) Ca2+1.75mmol/L (7mg/dl) Hypocalcemia Hypomagnesemia Normal serum Mg2+: 0.81.2mmol/L (2.0-3.0mg/dl) Mg2+0.6mmol/L (1.5mg/dl) Hypomagnesemia编辑ppt Common Solution of fluid The

55、rapy Non-electrolyte solution: 5glucose 10glucose Electrolyte solution: NaCl,Ringers solution NaHCO3,5 NaHCO3 10 KCl Mixed solutions: ORS编辑ppt编辑ppt ORS Composition of ORS编辑pptMolar concentration? mol=w(g)/MW mmol= w(g)/MW1000 NaCl(mmol)=2.6/58.51000=44mmol =Na(mmol)= Cl(mmol) Sodium Citrate ;Trisodi

56、um citrate (C6H5O7Na32H2O:294) Sodium Citrate(mmol)=2.9/2941000=10mmol Na(mmol)= 3citrate (mmol)= 3Sodium Citrate=30mmol ORSH20:1000ml编辑ppt编辑ppt Mechanism of ORS编辑ppt ORS Indications: mild or moderate without vomiting and abdominal distention Methods: mild dehydration: 50-80 ml/kg Moderate dehydrati

57、on: 80-100 ml/kg 8-12 hr编辑ppt Intravenous infusion: Indications: Moderate dehydration (serious vomiting) Severe dehydration 编辑ppt Volume of fluid in intravenous rehydration编辑ppt types of fluid in intravenous rehydration 编辑ppt编辑ppt Speed of intravenous rehydration : First phase: In the first 30min1hr

58、, 20ml/kg of isotonic sodium chloride solution or lactated Ringer solution (total amount300ml) need to be replaced. The remainder of deficit should be replaced within 812hours. Second phase: In the following 1216hours, focuses on provision of maintainance fluids (6080ml/kg.d) and replacement of ongo

59、ing losses (1040ml/kg.d).编辑ppt Hypernatremia dehydration Determine time for correction based on initial sodium concentration Na+ 145-157mmol/L: 24hr Na+ 158-170mmol/L: 48hr Na+ 171-183mmol/L: 72hr Na+ 184-194mmol/L: 84hr Control Sodium concentration or rate of IV fluid编辑ppt60-80ml/kg编辑ppt Correction

60、 of acidosis Acidosis may accompany dehydration, and although rehydration will correct this to an extent, if it is severe enough to cause air hunger, sodium bicarbonate can be added to the infusion. 5%NaHCO3(ml)=(-BE)0.5 BW(kg) 5%NaHCO3(ml)=(40-CO2CP) 0.5 BW(kg) Emergency situations : 5% NaHCO3 5ml/kg or 1.4% NaHCO3 20ml/kg serumHCO3 -5 m