小儿腹泻英文教学课件

1、Infantile Diarrhea2012.025th floor of Building No.6Content Definition Epidemiology Etiology and Predisposing factorPathogenesis Clinical manifestation DiagnosisManagement & preventionFluid therapy DiarrheaContent Definition Epidemiology Etiology and Predisposing factorPathogenesis Clinical manifesta

2、tion DiagnosisManagement & preventionFluid therapy DiarrheaDiarrhea-definitionDiarrhea is defined as an increase in the Fluidity, Volume, and Frequency of stools. Volume 10 ml/kg/d in children or 200g/day in adolescents FluidityDecrease in consistency (loose or liquid)Frequency Bowel movements3 per

3、24 hours ConstipationDiarrheaDiarrhea-definitionDiarrhea is defined as an increase in the Fluidity, Volume, and Frequency of stools. Volume 10 ml/kg/d in children or 200g/day in adolescents FluidityDecrease in consistency (loose or liquid)Frequency Bowel movements3 per 24 hours The sudden change of

4、stool characteristics is more important!Content Definition Epidemiology Etiology and Predisposing factorPathogenesis Clinical manifestation DiagnosisManagement & preventionFluid therapy DiarrheaEpidemiology High incidence and mortality European 0.5-1.9 episodes per person per yearConsume large amoun

5、ts of health care costs USA:1-2 episodes/child/year 1.5 Million medical consultations160,000 ER visits220,000 hospitalizations (mean hospital stay 3.4 days)$ 1.8 Billion per year of medical costsMortality rates: 32.2 deaths/100,000 live born in Afro-Americans (8.2 in whites)Dehydration Death Malnutr

6、itionGrowth retardationImpaired mental development Consequences of diarrhea in childrenAcute stageChronic stage leading causes of death in children in developing countries 15%malariameaslesHIVPerinatal diseasesothersARTIdiarrheaMortality from diarrhea diseases among children in developing countriesT

7、he mortality of diarrhea is decline:Development of economyProgress of Medicine Improvement of medical conditionsORS useBut Predisposing factorInfant digestive system is not well developed, and the function is immature:Lack of gastric acid secretion,-Lower enzyme activity,-Rapid gastric emptying (inf

8、ection & 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 inmature, prone to gastrointestinal dysfunction.More nutrition demand Because children are growing rapid

9、ly, they need more nutrition to meet their rapid growth.the burden of digestive system is heavier. Weakness of defense systemLack of gastric acid secretion, -rapid gastric emptying, -lower enzyme activity.The introgastric pathogenes cannot be killed thoroughly.The levels of serum IgA, IgM and the se

10、cretory IgA in intestinal tract are lower, so the immune defense is insufficient.Normal intestinal flora have not well established Bottle-feeding (or artificial feeding) Milk or/and bottle is prone to contaminated with pathogens during handlingMilk nutrition damagedBreast milk contains immune compon

11、ents:(sIgA, lactoferrin, lysozyme,etc.)E.coliContent Definition Epidemiology Etiology and Predisposing factorPathogenesis Clinical manifestation DiagnosisManagement & preventionFluid therapy DiarrheaEtiologyInfective factors (virus,bacteria,fungi,parasites)Noninfective factorsDietary factorInappropr

12、iate feeding Allergic Diarrhea Disaccharidase Deficiency ClimateSymptomatic Diarrhea EtiologyInfective factors (virus,bacteria,fungi,parasites)Noninfective factorsDietary factorInappropriate feeding Allergic Diarrhea Disaccharidase Deficiency ClimateSymptomatic Diarrhea Etiology-Infective factors Ro

13、ute of transmission: feces-mouth wayPathogens of infective factorsshigellaEtiology-Infective factorsViruses: The most Common pathogen in children with infected diarrhea. Rotavirus, Astrovirus, Noro virus, Coronavirus, Calicivirus, Enteric adenovirus, echo virus, cosackis virus, and so on. Usually oc

14、curs in the cold season(Autumn, winter).Rotavirus is the most severe enteric pathogen of childhood diarrhea. Etiology-Infective factorsBacteria:The second most common cause in children with infective diarrhea.Etiology-Infective factorsFungi: Candida albicans, aspergillus, mucorEtiology-Infective fac

15、torsParasites: Etiology-Infective factorsThe most important infective causes of acute diarrhea in developing countries in children are:Rotavirus/norovirusEnterotoxigenic Escherichia coliShigellaCampylobacter jejuniSalmonella typhimuriumEtiologyInfective factors (virus,bacteria,fungi,parasites)Noninf

16、ective factorsDietary factorInappropriate feeding Allergic Diarrhea Disaccharidase Deficiency ClimateSymptomatic Diarrhea Etiology-Non-Infective factorsDietary factorsInappropriate feeding (Dietary Diarrhea): OverfeedingIndigestible dietSudden change of formulaInappropriate feeding for a milk-fed ba

17、by shifting into solid food (too much, too early, too rapid)Disaccharidase Deficiency: Lactose IntolerancePrimary disaccharidase deficiency Secondary disaccharidase deficiency(Lactase deficiency )Allergic DiarrheaAllergic colitisEtiology-Non-Infective factorsClimateSeasonal variation affects the dig

18、estive function of young children: incidence of diarrhea is highest furing the early rainy seasonCold weather causes increasing of enterokinesiaHot weather causes decreasing of digestive enzyme and malfunction of digestive tractEtiology-Non-Infective factorsSymptomatic Diarrhea: Diarrhea is only one

19、 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 always mild, and recover with the primary disease getting better.The younger the ch

20、ildren, the more chance to get a symptomatic diarrhea accompanied by other diseases. Content Definition Epidemiology Etiology and Predisposing factorPathogenesis Clinical manifestation DiagnosisManagement & preventionFluid therapy DiarrheaPathogenesis of DiarrheaThe basic pathogenesis of diarrhea:Os

21、motic Diarrhea (Pathogenesis of Viral Diarrhea)Secretory Diarrhea( Pathogenesis of Enterotoxigenic Diarrhea) Invasive diarrhea(Exudative diarrhea, Inflammatory diarrhea) Motility abnormalitiesPathogenesis of DiarrheaThe basic pathogenesis of diarrhea:Osmotic Diarrhea (Pathogenesis of Viral Diarrhea)

22、Secretory Diarrhea( Pathogenesis of Enterotoxigenic Diarrhea) Invasive diarrhea(Exudative diarrhea, Inflammatory diarrhea) Motility abnormalitiesOsmotic DiarrheaPathogens:VirusGiardia EAECCharacteristics:Watery stoolStool WBC(-)Stool RBC(-)Diarrhea improved after fastingPathogenesis of DiarrheaThe b

23、asic pathogenesis of diarrhea:Osmotic Diarrhea (Pathogenesis of Viral Diarrhea)Secretory Diarrhea( Pathogenesis of Enterotoxigenic Diarrhea) Invasive diarrhea(Exudative diarrhea, Inflammatory diarrhea) Motility abnormalitiesSecretory DiarrheaPathogens:Vibrio cholerae (cholera)Enterotoxigenic Escheri

24、chia Coli (ETEC) Staphylococcus aureusClostridium difficileCharacteristics:Watery stoolStool WBC(-)Stool RBC(-)Diarrhea without improvement after fastingPathogenesis of DiarrheaThe basic pathogenesis of diarrhea:Osmotic Diarrhea (Pathogenesis of Viral Diarrhea)Secretory Diarrhea( Pathogenesis of Ent

25、erotoxigenic Diarrhea) Invasive diarrhea(Exudative diarrhea, Inflammatory diarrhea) Motility abnormalitiesInvasive DiarrheaInvasive organisms:Shigella speciesEIEC (enteroinvasive E. coli)Campylobacter jejuniSalmonella typhimuriumYersinia enterocoliticaCharacteristics:Mucopurulent bloody stoolStool W

26、BC (+)Stool RBC (+)Abdominal painTenesmusFeverToxic appearance Pathogenesis of DiarrheaPathogenesis of Dietary DiarrheaInappropriate diet OverfeedingIndigestible dietSudden change of formulaInappropriate solid food adding(too much, too early or too rapid, and so on.) Clinical features of Dietary Dia

27、rrheaWatery like diarrheaStool WBC (-)Stool RBC (-)anorexia Abdominal painFeverToxic appearanceDyspepsiaPathogenesis of Diarrhea The basic pathogenesis of diarrhea:Osmotic diarrheaSecretory diarrheaExudative diarrhea:Invasive diarrhea, Inflammatory diarrhea Motility abnormalities Diarrhea is not cau

28、sed by a single mechanism, but occur in a variety of mechanisms.Content Definition Epidemiology Etiology and Predisposing factorPathogenesis Clinical manifestation DiagnosisManagement & preventionFluid therapy DiarrheaClinical manifestations of diarrhea Common symptomsClassificationWater-electrolyte

29、 disturbances, acid-base imbalance(see detail in next section)Clinical characteristics of diarrhea caused by special pathogen(rotavirus infection)Clinical manifestations of diarrheaCommon symptomsSite of action: small intestine:Virusenterotoxin-producing organismsenteroadhesive organisms large intes

30、tine:invasive organismscytotoxin-producing organismsenteroadhesive organismsGastrointestinal symptom:Anorexia(Loss of appetite)NauseaVomitDiarrhea( watery or bloody)with or without abdominal painSystemic symptom Fever, paleDebilitation/restlessness/irritability Lethargy/depression/indisposition, etc

31、.Water-electrolyte disturbances,base-acid imbalance.(see detail in next section)Clinical manifestations of diarrheaClassificationClinical manifestations of diarrheaClassificationClinical manifestations of diarrheaClinical characteristics of diarrhea caused by special pathogen-rotavirusRotavirusP1-44

32、G1-14A-G groupRotavirusVirology: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 pathogen in childhood diarrheaEpidemiology:Peak season: autumn/

33、winter, “Autumn diarrhea”Contagiousness: fece-mouth way or spread by gasoloid. Peak age: 6M2yrs old.RotavirusMechanisms:Pathogenesis of Viral DiarrheaNSP4RotavirusContent Definition Epidemiology Etiology and Predisposing factorPathogenesis Clinical manifestation DiagnosisManagement & prevention Flui

34、d therapy DiarrheaDiagnosis 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 Physical examinationHistory Assess dehydrationEvaluat

35、ion of acute diarrhea patient Onset,frequency,quantityCharacter-bile,blood,mucusVomitingPast medical historyUnderlying medical conditionsEpidemiological clues Body weightTemperatureHart rateRespiratory rateBlood pressureGeneral appearance,alertnessPulse and blood pressurePosture hypotensionMucosa an

36、d tearsSunken eyes,skin turgorCapillary refill,jugular venous pressureSunken fontanelle Can stool analysis differentiate a Bacterial from a Nonbacterial Agent? Fecal marker?Stool cultures are usually unnecessary for immunocompetent patients who present within 24 hours after the onset of acute, water

37、y diarrhea. Microbiologic investigation is indicated in patients who are dehydrated or febrile or have blood or pus in their stool. How about lab. findings?Can stool analysis differentiate a Bacterial from a Nonbacterial Agent? Fecal marker?Stool cultures are usually unnecessary for immunocompetent

38、patients who present 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?Electrolytes should be measured:In moderately dehydrated children whose hist

39、ory and physical examination findings are inconsistent with a straight diarrheal diseaseAll severely dehydrated children (Va, D).In all children starting intravenous (IV) therapy,and during therapybecause hyper- or hyponatremia will alter the rate at which IV rehydration fluids will be given (Va, D)

40、. Content Definition Epidemiology Etiology and Predisposing factorPathogenesis Clinical manifestation DiagnosisManagement & prevention Fluid therapy DiarrheaDo We Know How to Treat It?DiarrheaManagement of diarrhea Management of diarrheaFluid therapyDiet and Nutrition therapyDrug therapy Drug therap

41、y Antimicrobial therapy Adsorbents ProbioticsSupplemental zinc therapy, multivitamins, and minerals Antiemetics Antidiarrheal treatment Antisecretory agents Supplemental zinc therapy, multivitamins, and minerals 6M: 20 mg zinc for 14 days(WHO&UNICEF).6M : 10 mg zinc for 14 days(WHO&UNICEF).Antiemeti

42、cs 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) Antidiarrheal treatmentNonspecific antidiarrheal treatmentAntimotility:Antisecretory agents: Preve

43、ntionWater, 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 Weaning foods are vehicles of enteric infection To avoid misuse of antibioticsMicr

44、onutrient supplementation: depends on the childs overall immunologic and nutritional statefurther research is neededVaccines: Salmonella typhi: Shigella organisms:V. cholerae:ETEC vaccines: Rotavirus: RotaTeq (Merck) Rotarix (GSK) Measles immunization:Content Definition Epidemiology Etiology and Pre

45、disposing factorPathogenesis Clinical manifestation DiagnosisManagement & preventionFluid therapy DiarrheaFluid therapyThe characteristics of childrens water-electrolytes balanceDisturbances of water and electrolytesCommon Solution of fluid TherapyIntravenous infusionFliud therapy The characteristic

46、s of childrens water-electrolytes balance Volume and distribution of body fluid Composition of electrolyte in body fluids The characteristics of water metabolism in childrenLarge water requirements, high water exchange rateHigh metabolism,need more water. Insensible loss of water loss (double adults

47、 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 )Disturbances of water and electrolytesDehydration HypokalemiaMetabolic acidosisHypocalcemia HypomagnesemiaDehydrationAssessment of dehydrationM

48、ildModerateSevereThe types of dehydrationHypotonic dehydrationIsotonic dehydrationHypertonic dehydrationeyesIsotonicHypertonicHypotonicNormalInterstitial fluidIntracellular fluidPlasmaHypotonic dehydrationSodiumwaterOsmotic pressure of ECFICFWater will shift from ECF to ICFICF ECFCell edemacirculato

49、ry failure+Isotonic dehydrationNormalInterstitial fluidIntracellular fluidPlasmaSodium=waterOsmotic pressure of ECF=ICFNo water shift between ECF and ICFICF- ECFNormal Cell shapecirculatory failure+Hypertonic dehydrationNormalInterstitial fluidIntracellular fluidPlasmaSodiumwaterOsmotic pressure of

50、ECFICFWater will shift from ICF to ECFICF ECFCell dehydrationcirculatory failure+HypokalemiaSerum K+ 3.5mmol/LPathogenesisintake insufficientLoss of kalium from kidneys or gastrointestinal tractAbnormal kalium distribution (K shifts into the cells).alkalosis, insulin therapy、periodic paralysis）Burn,

51、 dialysis, etc. Hypokalemia -Clinical manifestationsNervous systemdepressedMuscleMuscular tension decreased，Abdominal distension，Respiratory muscle paralysis.Cardiovascular systemTachycardia, lower heart sound, arrhythmia, Bradycardia，atrioventricular block, Adams-Stokes syndrome,Electrocardiogram s

52、hows U wave appearing，UT， flatten T wave. Prolonged Q-T period,depressed S-TKidneyconcentrating function decreased, urine volume increased(polyuria)Metabolic acidosisSerum pH 7.35PathogenesisThe lose of large amount of basic substances（from gastrointestinal tract, kidneys）Too much Acid metabolites （

53、because of hungriness, diabetes, renal failure, hypoxia）Too much acid substance intake （long time to take calcium chloride, ammonium chloride, amino acid. ） Degrees of acidosisClinical features: Mild acidosis:symptoms is not obvious, only faster breathingSereve acidosis : depressed, irritable, letha

54、ry, coma, deep and fast breathing, (kussmauls breathing), breath with ketone smell, red lipnausea and vomitingHypocalcemia Normal serum Ca2+: 2.22.7mmol/L (911mg/dl)Ca2+1.75mmol/L (7mg/dl) HypocalcemiaHypomagnesemiaNormal serum Mg2+: 0.81.2mmol/L (2.0-3.0mg/dl)Mg2+0.6mmol/L (1.5mg/dl) Hypomagnesemia

55、Common Solution of fluid TherapyNon-electrolyte solution: 5glucose10glucoseElectrolyte solution:0.9 NaCl, Ringers solution1.4NaHCO3, 5 NaHCO310 KClMixed solutions:ORSORSComposition of ORSMolar concentration?mol=w(g)/MWmmol= w(g)/MW1000NaCl(mmol)=2.6/58.51000=44mmol =Na(mmol)= Cl(mmol)Sodium Citrate ;Trisodium citrate (C6H5O7Na32H2O:294) Sodium Citrate(mmol)=2.9/2941000=10mmolNa(mmol)= 3citrate (mmol)= 3Sodium Citrate=30mmol ORSH20:1000mlMechanism of ORSORS Indications: mild or moderate without vomiting and abdominal distentionMethods: mild dehydration: 50-80 ml/