儿科学英文课件：19 infantile diarrhea

Infantile Diarrhea2012.025th floor of Building No.6Content Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management&prevention Fluid therapy DiarrheaContent Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management&prevention Fluid therapy DiarrheaDiarrhea-definition Diarrhea 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 Fluidity Decrease in consistency(loose or liquid)Frequency Bowel movements3 per 24 hours ConstipationDiarrheaDiarrhea-definition Diarrhea 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 Fluidity Decrease in consistency(loose or liquid)Frequency Bowel movements3 per 24 hours The sudden change of stool characteristics is more important!Content Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management&prevention Fluid therapy DiarrheaEpidemiology High incidence and mortality European 0.5-1.9 episodes per person per year 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 Billion per year of medical costs Mortality rates:32.2 deaths/100,000 live born in Afro-Americans(8.2 in whites)Dehydration Death Malnutrition Growth retardation Impaired 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 countriesThe mortality of diarrhea is decline:Development of economyProgress of Medicine Improvement of medical conditionsORS useBut Predisposing factor Infant digestive system is not well developed,and the function 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 inmature,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.Weakness of defense system Lack 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 secretory 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 handling Milk nutrition damaged Breast milk contains immune components:(sIgA,lactoferrin,lysozyme,etc.)E.coliContent Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management&prevention Fluid therapy DiarrheaEtiology Infective factors(virus,bacteria,fungi,parasites)Noninfective factors Dietary factor Inappropriate feeding Allergic Diarrhea Disaccharidase Deficiency Climate Symptomatic Diarrhea Etiology Infective factors(virus,bacteria,fungi,parasites)Noninfective factors Dietary factor Inappropriate feeding Allergic Diarrhea Disaccharidase Deficiency Climate Symptomatic Diarrhea Etiology-Infective factors Route 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 occurs in the cold season(Autumn,winter).Rotavirus is the most severe enteric pathogen of childhood diarrhea.Etiology-Infective factors Bacteria:The second most common cause in children with infective diarrhea.Etiology-Infective factors Fungi:Candida albicans,aspergillus,mucorEtiology-Infective factors Parasites:Etiology-Infective factors The most important infective causes of acute diarrhea in developing countries in children are:Rotavirus/norovirus Enterotoxigenic Escherichia coli Shigella Campylobacter jejuni Salmonella typhimuriumEtiology Infective factors(virus,bacteria,fungi,parasites)Noninfective factors Dietary factor Inappropriate feeding Allergic Diarrhea Disaccharidase Deficiency Climate Symptomatic Diarrhea Etiology-Non-Infective factors Dietary factors Inappropriate feeding(Dietary Diarrhea):Overfeeding Indigestible 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(Lactase deficiency)Allergic DiarrheaAllergic colitisEtiology-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 tractEtiology-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 always 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.Content Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management&prevention Fluid therapy DiarrheaPathogenesis 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 abnormalitiesPathogenesis 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 abnormalitiesOsmotic Diarrhea Pathogens:Virus Giardia EAEC Characteristics:Watery stool Stool WBC(-)Stool RBC(-)Diarrhea improved after fastingPathogenesis 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 abnormalitiesSecretory Diarrhea Pathogens:Vibrio cholerae(cholera)Enterotoxigenic Escherichia Coli(ETEC)Staphylococcus aureus Clostridium difficile Characteristics:Watery stool Stool WBC(-)Stool RBC(-)Diarrhea without improvement after fastingPathogenesis 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 abnormalitiesInvasive Diarrhea Invasive 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 Pathogenesis of Diarrhea Pathogenesis 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.)Clinical features of Dietary Diarrhea Watery like diarrhea Stool WBC(-)Stool RBC (-)anorexia Abdominal pain Fever Toxic appearanceDyspepsiaPathogenesis 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.Content Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management&prevention Fluid therapy DiarrheaClinical manifestations of diarrhea Common symptoms Classification Water-electrolyte disturbances,acid-base imbalance(see detail in next section)Clinical characteristics of diarrhea caused by special pathogen(rotavirus infection)Clinical manifestations of diarrhea Common symptoms Site of action:small intestine:Virus enterotoxin-producing organisms enteroadhesive organisms large intestine:invasive organisms cytotoxin-producing organisms enteroadhesive organisms Gastrointestinal symptom:Anorexia(Loss of appetite)Nausea Vomit Diarrhea(watery or bloody)with or without abdominal pain Systemic symptom Fever,pale Debilitation/restlessness/irritability Lethargy/depression/indisposition,etc.Water-electrolyte disturbances,base-acid imbalance.(see detail in next section)Clinical manifestations of diarrhea ClassificationClinical manifestations of diarrhea ClassificationClinical manifestations of diarrhea Clinical characteristics of diarrhea caused by special pathogen-rotavirusRotavirusP1-44G1-14A-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/winter,“Autumn diarrhea”Contagiousness:fece-mouth way or spread by gasoloid.Peak age:6M2yrs old.Rotavirus Mechanisms:Pathogenesis of Viral Diarrhea NSP4RotavirusContent Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management&prevention Fluid 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 dehydrationEvaluation 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 and 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,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?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,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 history and physical 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).Content Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management&prevention Fluid therapy DiarrheaDo We Know How to Treat It?DiarrheaManagement of diarrhea Management of diarrhea Fluid therapy Diet and Nutrition therapy Drug therapy Drug therapy Antimicrobial therapy Adsorbents Probiotics Supplemental 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).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)Antidiarrheal treatment Nonspecific antidiarrheal treatment Antimotility:Antisecretory agents:Prevention 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 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 Vaccines:Salmonella typhi:Shigella organisms:V.cholerae:ETEC vaccines:Rotavirus:RotaTeq(Merck)Rotarix(GSK)Measles immunization:Content Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management&prevention Fluid therapy DiarrheaFluid therapy The characteristics of childrens water-electrolytes balance Disturbances of water and electrolytes Common Solution of fluid Therapy Intravenous infusionFliud therapy The characteristics of childrens water-electrolytes balance Volume and distribution of body fluid Composition of electrolyte in body fluids The characteristics of water metabolism 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)Disturbances of water and electrolytes Dehydration Hypokalemia Metabolic acidosis Hypocalcemia Hypomagnesemia Dehydration Assessment of dehydration Mild Moderate Severe The types of dehydration Hypotonic dehydration Isotonic dehydration Hypertonic dehydrationeyesIsotonicHypertonicHypotonicNormalInterstitial fluidIntracellular fluidPlasmaHypotonic dehydrationSodiumwaterOsmotic pressure of ECFICFWater will shift from ECF to ICFICF ECFCell edemacirculatory 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 ECFICFWater will shift from ICF to ECFICF ECFCell dehydrationcirculatory failure+Hypokalemia Serum K+3.5mmol/L 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.Hypokalemia-Clinical manifestations Nervous system depressed 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,depressed S-T Kidney concentrating function decreased,urine volume increased(polyuria)Metabolic acidosis Serum pH 7.35 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 much acid substance intake（long time to take calcium chloride,ammonium chloride,amino acid.）Degrees of acidosis Clinical features:Mild acidosis:symptoms is not obvious,only faster breathing Sereve acidosis:depressed,irritable,lethary,coma,deep and fast breathing,(kussmauls breathing),breath with ketone smell,red lip nausea and vomiting 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 Common Solution of fluid Therapy Non-electrolyte solution:5glucose 10glucose Electrolyte solution:0.9 NaCl,Ringers solution 1.4NaHCO3,5 NaHCO3 10 KCl Mixed solutions:ORS ORS Composition of ORSMolar concentration?mol=w(g)/MW mmol=w(g)/MW1000 NaCl(mmol)=2.6/58.51000=44mmol =Na(mmol)=Cl(mmol)Sodium Citrate;Trisodium citrate(C6H5O7Na32H2O:294)Sodium Citrate(mmol)=2.9/2941000=10mmol Na(mmol)=3citrate(mmol)=3Sodium Citrate=30mmol ORSH20:1000ml Mechanism of ORS ORS Indications:mild or moderate without vomiting and abdominal distention Methods:mild dehydration:50-80 ml/kg Moderate dehydration:80-100 ml/kg 8-12 hr(4-6hr)Intravenous infusion:Indications:Moderate dehydration(serious vomiting)Severe dehydration Volume of fluid in intravenous rehydration types of fluid in intravenous rehydration Speed of intravenous rehydration:First phase:In the first 30min1hr,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(4-6hr).Second phase:In the following 1216hours,focuses on provision of maintainance fluids(6080ml/kg.d)and replacement of ongoing losses(1040ml/kg.d).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 fluid60-80ml/kg Correction 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 mmol/L Correction of hypokalemia Potassium chloride injection(10%KCl)needs to be added to the infusion once urine output is established Mild hypokalemia:200300mg/（kgd）/23ml/（kgd）10%KCl Severe hypokalemia:300450mg/（kgd）/34.5ml/kg.d 10%KCl Concentration of potassium chloride under 0.3%Maintainance:4-6days Correction of Hypocalcemia 10%Calcium Gluconate 10ml+10%GS 10ml IV Correction of Hypomagnesemia 25%Mg.Sulfas 0.20.4ml/kg deep IM Q6hRemember this girl?The next day Content Definition Epidemiology Etiology and Predisposing factor Pathogenesis Clinical manifestation Diagnosis Management&prevention Fluid therapy Diarrhea