P1:IML/OVY P2:IML/OVY QC:IML/OVY T1:IML GRBT084-465 McMillan-2257G GRBT084-McMillan-v23.cls February25,2006 0:10 ii P1:IML/OVY P2:IML/OVY QC:IML/OVY T1:IML GRBT084-465 McMillan-2257G GRBT084-McMillan-v23.cls February25,2006 0:10 F O U R T H E D I T I O N OSKI’S PEDIATRICS PRINCIPLES & PRACTICE i P1:IML/OVY P2:IML/OVY QC:IML/OVY T1:IML GRBT084-465 McMillan-2257G GRBT084-McMillan-v23.cls February25,2006 0:10 ii P1:IML/OVY P2:IML/OVY QC:IML/OVY T1:IML GRBT084-465 McMillan-2257G GRBT084-McMillan-v23.cls February25,2006 0:10 F O U R T H E D I T I O N OSKI’S PEDIATRICS PRINCIPLES & PRACTICE Editor-in-Chief Editors Julia A. McMillan, MD Ralph D. Feigin, MD ProfessorofPediatrics DistinguishedServiceProfessor ViceChairforEducation BaylorCollegeofMedicine DepartmentofPediatrics Chairman,DepartmentofPediatrics Director,ResidencyTrainingProgram BaylorCollegeofMedicine AssociateDeanforGraduateMedicalEducation Physician-in-Chief JohnsHopkinsUniversitySchoolofMedicine TexasChildren’sHospital JohnsHopkinsHospital Chief,PediatricService Baltimore,Maryland BenTaubGeneralHospital Chief,PediatricService TheMethodistHospital Houston,Texas Catherine DeAngelis, MD, MPH ProfessorofPediatrics JohnsHopkinsUniversitySchoolofMedicine Editor-in-Chief JAMA Chicago,Illinois M. Douglas Jones, Jr., MD Professor DepartmentofPediatrics SectionofNeonatology TheUniversityofColoradoSchoolofMedicine TheChildren’sHospital Denver,Colorado 389 Contributors iii P1:IML/OVY P2:IML/OVY QC:IML/OVY T1:IML GRBT084-465 McMillan-2257G GRBT084-McMillan-v23.cls February25,2006 0:10 AcquisitionsEditor:AnneM.Sydor/SonyaSeigafuse DevelopmentalEditor:KathleenScogna ManagingEditor:NicoleT.Dernoski EditorialAssistant:SarahGranlund ProjectManager:NicoleWalz SeniorManufacturingManager:BenjaminRivera DesignerCoordinator:HollyReidMcLaughlin CoverDesigner:ChristineJenny Compositor:TechBooks Printer:QuebecorWorld-Taunton ©2006byLIPPINCOTTWILLIAMS&WILKINS,aWoltersKluwerbusiness 530WalnutStreet Philadelphia,PA19106USA LWW.com Allrightsreserved.Thisbookisprotectedbycopyright.Nopartofthisbookmaybe reproducedinanyformorbyanymeans,includingphotocopying,orutilizedbyany informationstorageandretrievalsystemwithoutwrittenpermissionfromthecopyright owner,exceptforbriefquotationsembodiedincriticalarticlesandreviews.Materials appearinginthisbookpreparedbyindividualsaspartoftheirofficialdutiesasU.S. governmentemployeesarenotcoveredbytheabove-mentionedcopyright. PrintedintheUSA LibraryofCongressCataloging-in-PublicationData Oski’spediatrics:principles&practice/editor-in-chief,JuliaA.McMillan;editors,Ralph D.Feigin,CatherineD.DeAngelis,M.DouglasJones,Jr.—4thed. p.;cm. Includesbibliographicalreferencesandindex. ISBN0-7817-3894-6(alk.paper) 1.Pediatrics. I.McMillan,JuliaA.II.Oski,FrankA.Principlesandpracticeof pediatrics.III.Title:Pediatrics. [DNLM:1.Pediatrics. WS100O8162006] RJ45.P67542006 618.92—dc22 2006000380 Carehasbeentakentoconfirmtheaccuracyoftheinformationpresentedandtodescribe generallyacceptedpractices.However,theauthors,editors,andpublisherarenotresponsible forerrorsoromissionsorforanyconsequencesfromapplicationoftheinformationin thisbookandmakenowarranty,expressedorimplied,withrespecttothecurrency, completeness,oraccuracyofthecontentsofthepublication.Applicationofthisinformation inaparticularsituationremainstheprofessionalresponsibilityofthepractitioner. Theauthors,editors,andpublisherhaveexertedeveryefforttoensurethatdrugselection anddosagesetforthinthistextareinaccordancewithcurrentrecommendationsand practiceatthetimeofpublication.However,inviewofongoingresearch,changesin governmentregulations,andtheconstantflowofinformationrelatingtodrugtherapyand drugreactions,thereaderisurgedtocheckthepackageinsertforeachdrugforanychange inindicationsanddosageandforaddedwarningsandprecautions.Thisisparticularly importantwhentherecommendedagentisaneworinfrequentlyemployeddrug. SomedrugsandmedicaldevicespresentedinthispublicationhaveFoodandDrug Administration(FDA)clearanceforlimiteduseinrestrictedresearchsettings.Itisthe responsibilityofthehealthcareprovidertoascertaintheFDAstatusofeachdrugordevice plannedforuseintheirclinicalpractice. Topurchaseadditionalcopiesofthisbook,callourcustomerservicedepartmentat(800) 638-3030orfaxordersto(301)223-2320.Internationalcustomersshouldcall(301) 223-2300. VisitLippincottWilliams&WilkinsontheInternet:http://LWW.com.Lippincott Williams&Wilkinscustomerservicerepresentativesareavailablefrom8:30amto6pm, EST. 10987654321 iv P1:IML/OVY P2:IML/OVY QC:IML/OVY T1:IML GRBT084-465 McMillan-2257G GRBT084-McMillan-v23.cls February25,2006 0:10 FRANK A. OSKI, MD (1932–1996) FrankA.Oskiwasaleader,amentor,avisionary,ascientist, Pediatriciansandchildrenthroughoutthecountryandthe andaclinician,butmostofallhewasateacher.Hewelcomed world have benefited from Frank’s teaching, but those fortu- studentswillingtotakeontheawesomeresponsibilityofpro- nateenoughtohavebeenhisstudentshadtheirliveschanged vidingmedicalcareforchildren,buthedemandedexcellence byhim.Heremindedhisstudentsoftenthattheyhadanobli- inthatendeavor. gationtotheirpatientsandtotheirownstudentstorealizethat Frankwaschairmanoftwodepartmentsofpediatrics—at theycouldneverknowasmuchastheyshould.Frank’sexpec- theStateUniversityofNewYorkHealthScienceCenteratSyra- tationswerehigh,butoneofhismanyparticulargiftswasthat cuse(1972to1985)andatJohnsHopkinsUniversitySchool heidentifiedstrengthsineachofhisstudentsandthenhelped of Medicine (1985 to 1994). He was editor or author of 13 eachachievethepotentialheknewheorshehad.Hislegacy booksforpediatriciansandhematologists,authored293arti- tothefieldofpediatricsisthathehelpedmanyfuturepedia- cles,andservedonnineeditorialboardsofpediatricjournals triciansbecomestronger,wiser,andmoreconfidentthanthey and as the editor-in-chief of The Yearbook of Pediatrics and everthoughttheycouldbe.Hispersonallegacyisthat,because Contemporary Pediatrics. As the founding editor-in-chief of ofhim,weknowmoreaboutwhataprivilegeitistoteach. thistextbook,hewroteintheprefaceofthefirstedition,“Our goalhasbeentorepresentaccuratelyandfullythebroadand JuliaA.McMillan,MD rich tapestry that is pediatrics today.” No thread was more CatherineD.DeAngelis,MD importanttothattapestryduringthepastthreedecadesthan RalphD.Feigin,MD Frank. JosephB.Warshaw,MD v P1:IML/OVY P2:IML/OVY QC:IML/OVY T1:IML GRBT084-465 McMillan-2257G GRBT084-McMillan-v23.cls February25,2006 0:10 vi P1:IML/OVY P2:IML/OVY QC:IML/OVY T1:IML GRBT084-465 McMillan-2257G GRBT084-McMillan-v23.cls March21,2006 6:57 ■ D E D I C AT I O N TO JOSEPH B. WARSHAW, MD (1936–2003) ThisfourtheditionofOski’sPediatrics:PrinciplesandPractice inandaptitudeforscientificexplorationtopursuecareersthat isdedicatedtothememoryofJosephB.Warshaw,M.D.,one would result in improved health for children throughout the of the editors of the first three editions of this text. Joe died world.AttheUniversityofVermont,wherehewasDeanofthe in December, 2003, of multiple myeloma. He was an active College of Medicine at the time of his death, he spearheaded participantintheplanningandinitialrevisionsforthecurrent thecreationoftheM.D./Ph.D.programandtheschool’snew edition. medicalcurriculum. Joe was a pediatrician, a neonatologist, a developmental Joehadenthusiasmandenergythatcaughteveryonearound biologist, and a leader in academic medicine. Most impor- himintoitsvortex.Helovedlifeandlivedittothefullest.He tantly, however, he was an educator with an instinct for cre- displayedsincereinterestandappreciationforthosefortunate ating environments and programs in which young physician enough to work with him or to be part of his family, and he scientists could thrive. Joe’s research efforts led to improved consideredeveryonepartofhisfamily.Hewasanadvocatefor understandingoffetalgrowthanddevelopmentandapprecia- students,fortrainees,forhisfaculty,andforchildren.Oski’s tionforthecomplexitiesofneonatalbiochemicaladaptation. Pediatrics: Principles and Practice is only a part of the pro- As Chair of the Departments of Pediatrics at the University foundlegacyJoeleavestopediatrics,itspractitioners,andits of Texas Southwestern Medical School at Dallas and at Yale scientists. UniversitySchoolofMedicine,hefosteredthedevelopmentof departmentsofpediatricswhosefacultymembersforgedacon- sistent link between molecular biology and clinical medicine. JuliaA.McMillan,MD JoehelpedfoundthePediatricianScientistDevelopmentPro- CatherineD.DeAngelis,MD gram,aneffortledbythechairsofAmericandepartmentsof RalphD.Feigin,MD pediatrics to encourage pediatricians with particular interest M.DouglasJones,Jr.,MD vii P1:IML/OVY P2:IML/OVY QC:IML/OVY T1:IML GRBT084-465 McMillan-2257G GRBT084-McMillan-v23.cls February25,2006 0:10 viii