NeonatalHyalineMembraneDisease(HMD)

新生兒肺透明膜病

1WhatisHMD?

alsocalled,

NeonatalRespiratoryDistressSyndrome(NRDS)-新生兒呼吸窘迫綜合征

一.

Introduction2Mostcommoncauseof

respiratoryfailure

intheprematureinfants,correlatingwithimmaturestructuralandfunctionallung.

OccurringfrequentlyininfantswithGA＜34w,theincidenceisinverselyproportionaltotheGAandbirthweight.Reasonissurfactantdeficiency,inturn,leadedtoatelectasis.Thereishyalinemembraneincollapsedalveoli

byphotomicrograph.

3incidence

≤28w:50%～80%32to36w:

15%～30%＞37w:＜5%

Rarelyatfullterminfants≤4二.EtiologyandPathophysiologyWhatcausesHMD?

WhoareaffectedbyHMD?5Etiology(1)----deficiencyofPulmonary

Surfactant

（basiccause）6Pulmonary

Surfactant(PS)--肺表面活性物質acomplexcomposedoflipidsandproteinsinfluidliningofalveolarsurfacesecretedbythecellsofthe

alveolistartingin20w,butlowbefore35w,toadultlevelafter3~7dofbirthhalf-life12~24h7SurfactantCompositionProtein(SP-A,B,C,D)11.1%Totallipid85-90%

Phosphatidylcholine磷脂80-90%(Lecithin磷脂酰膽堿/卵磷脂70-80%

)

Phosphatidylethanolamine

乙醇胺

5.2%Cholesterol膽固醇

6-8%Sphingomyelin鞘磷脂1.5%Lysophosphatidylcholine溶酶體膽堿0.9%Inmaturelung,Phospholipid/Sphingomyelin(L/S)≥28PS-function

reducethesurface

tension

oflungalveolikeeplungopenatendofexpirationpreventingthealveolifromcollapsingimmunomodulatoryeffects:巨噬細胞的吞噬、殺菌和趨化活性producednaturallyinthelungstokeepthelungalveoliopen.AlveoliwithoutPSAlveoliwithPS9FunctionofPSdecreasealveolarsurfacetension(

lungcompliance),andreducesrespiratoryworkMaintainalveoliinflationandfunctionalresidualcapacity(功能殘氣量）Acceleratelungfluidabsorption,reducealveolareffusionPathogenOpsonization,alveolarmacrophageactivation

increaseoxygenation—增加氧合improveventilation/perfusion—促進通氣anti-inflammation—抗炎作用10alveolarsurfacetension肺泡腔液面壓力液體薄層表面張力11PS是保障肺泡發揮換氣功能的關鍵PS正常時PS含量不足

/功能異常時吸氣時呼氣時12

IncreasedRisk

DecreasedRisk

Prematurity

早產Maternaldiabetes

糖尿病母親Cesareandelivery

withoutlaborPerinatalasphyxia

窒息Chorioamnionitis

絨毛膜羊膜炎

Multiplegestation

多胎Caucasian,malesex

白種人,男性FamilialpredispositonChronicintrauterinestressProlongedruptureofmembranesMaternalhypertensionIUGR/SGA宮內生長遲緩Antenatalmaternalsteroidsuse母親產前使用激素ThyroidhormoneEtiology(2)13PreterminfantsoftenhaveimmaturelungswithinadequatePS14Pathogenesis

Pulmonaryimmaturityresultsinsurfactantdeficiency

Alveolicollapseattheendofexpirationleadstorespiratoryfailure

Surfactantdeficiencymayariseafterasphyxia,shockandacidosisalveolar

surfacetensionishigherDiminishedPSPulmonaryatelectasisImpairedgasexchange(hypoxiaandacidosis)PulmonaryarteryhypertensionRight–to-leftshuntingPulmonarycapillaryleakedproteinForminghyalinemembrane15嗜伊紅透明膜肺透明膜病—發病機理肺泡表面張力PS缺乏肺泡不張缺氧、酸中毒肺動脈高壓，PDA肺間質水腫纖維蛋白沉著于肺泡內表面氣體彌散障礙

肺泡萎陷、肺順應性

潮氣量、通氣量

肺泡通透性增加16

AlveolarSurfaceTension

AtelectasisLungcompliancedecreased.Functionalresidualcapacitydecreased.Lungvolumereduced.AlveolarventilationdecreasedAirwayresistanceremainsnormal肺順應性氣道阻力功能殘氣量17三.Pathology18

Gross––thelungcollapsed,firm,darkred,andliver-like.decreasedlungvolume19正常肺泡RDS:水腫，血管充血，毛細血管滲出，肺泡萎陷20RDS:

Atelectasis,pulmonaryedema,collapsedalveoli

fillwith

fibrin,cellulardebrisandhyalinemembrane21RDS:

hyalinemembranes

22

四.ClinicalManifestation23ClinicalPresentationRespiratorydistress

respiratoryfailureoccurinfirstfewhoursofageandgetsprogressivelyworse

--生后進行性呼吸困難

TachypneaRR>60bpm，Cyanosis(increasedneedtooxygen)chestretractions

--三凹征nasalflaring--鼻扇

expiratorygrunting--呻吟24

Featuresofrespiratoryfailure

respiratoryfailureoccuratorsoonafterbirth,notlongerthan12h;

thesymptomsusuallypeakonthethird

day

whendiuresisstarts,

thesymptomscanresolvequicklyby

PSsupplement.25Circulatoryinsufficiency

PDA/PPHN/ypotensionHypotensionCongestiveheartfailure（duetoleft-to-rightshuntingduringrecovery

）ShockIntracranialHemorrhageOthers:pulmonaryhemorrhage,

pulmonaryinfectionscomplicationsofassistedventilation—emphysema,pneumothorax,

ventilator-associatedpneumonia，BPD--Complications26RadiographicChanges1.bell-shapedthorax(lessvolumelung)2.thelungsarehypoaerated低透亮度bilateral,diffuse,homogeneousreticulogranularopacities

彌漫、均勻的網狀顆粒影3.airbronchograms-peripherallyextending支氣管充氣征4.unclearnessofthecardiac/diaphragmaticsilhouette

心臟、橫隔輪廓不清，orwhitelung白肺27Classicrespiratorydistresssyndrome(RDS).28ModerateNRDS.

Thereticulogranularpatternismoreprominent.Thelungsarehypoaerated.peripherallyextendingairbronchograms

arepresent.

29SevereRDS.Reticulogranularopacities,prominentairbronchograms,totalobscurationofthecardiacsilhouette.303132ComplicationofRDSarighttensionpneumothoraxwithherniationofrightupperlungacrossmidline.pneumomediastinum

33LaboratoryFindingsBloodgasanalysis:hypoxemia,hypercapnia,andrespiratoryacidosis

Phospholipid(PL)/Sphingomyelin(S)<2:1;orPhosphatidylglycerol(PG):negativeShaketestorBubblestest:

amnioticfluid(gastricaspirate),

negative

34BubblestestorShaketest:

95%alcohol1mlSample1mlShake15”Negativeamnioticfluid,gastricaspirate35五.DiagnosisDifferentialDiagnosis36DiagnosisDiagnosiscanbedecidedbyacombinationofassessments,including:

medicalhistory:GA,Diabeticmother,Asphyxia,male,Bubblestest(-)clinicalfeatures:

respiratorydistressoccuredinfirstfewhoursofageandgotprogressivelyworsechestX-ray:

confirmedbloodgases:37

Theinfantisalmostalwayspreterm.Onlyoccasionallyinterminfant.TerminfantwithHMDareusuallyborntowomenwithpoorlycontrolleddiabetes.

Bubblestestofamnioticfluidorgastricaspirateisnegative,indicatsinadequatesurfactant.Theinfantdevelopsrespiratorydistressatorsoonafterdelivery.Thesignsofrespiratordistressgraduallybecomeworseduringthefirst48hoursafterbirth.

ChestX-rayisabnormalandshowssmalllungswithreticulogranularopacities.AtypicalchestX-rayisneededtomakeadefinitediagnosisHMD.Diagnosis38DifferentialDiagnosis

PulmonarycausesofrespiratorydistressWetlungMeconiumaspirationPneumoniaExtra-pulmonarycausesofrespiratorydistressPneumothoraxHeartfailureDiaphragmaticherniaMetabolicacidosisAnaemiaPolycythaemia39

“Wetlung”orTransienttachypneaofthenewborn(TTN)---濕肺

Amnioticfluidormeconiumaspirationsyndrome

---羊水或胎糞吸入綜合征

GroupBhemolyticStreptococcuspneumonia

---B組溶血性鏈球菌肺炎DifferentialDiagnosis40MeconiumAspiration

（MAS）

nodularnonhomogeneousdensities(bilateral,irregularcoarseinfiltrates),mayhavepleuraleffusions,usuallyincreasedlungvolume.

(不均,不規則粗大高密度影,肺容積增大,肺氣腫,肺不張等）指胎兒在宮內或娩出過程吸入被胎糞污染的羊水，發生氣道阻塞、肺內炎癥和一系列全身癥狀。特點：生后出現呼吸困難，但不呈進行性發展。可合并“氣漏綜合征”、PPHN、ARDS、肺部感染。多見于足月兒、過期產兒，有窒息史或羊水糞染史，胸片可有不規則斑片狀陰影，肺氣腫明顯。41MeconiumAspiration

不均勻密度增高影，肺氣腫，42diffuse,coarsenodularopacities;focalemphysema.Lungsareusuallyhyperaerated.MeconiumAspiration

43FluidinthefissureWetlung

Hyperaeration；BilateralreticulogranulardensitiesarefleetinganddisappearwithventilationTransienttachypneaofthenewborn(TTN)

多見于足月兒，剖宮產。呼吸困難逐漸減輕、消失，病程較短，呈自限性，預后良好；x線：肺門紋理粗和斑點狀影，常見水平線。44Wetlung

bilateral

(nonhomogeneous)densities;interstitialedemaandpleuraleffusions;hyperaeration

densitiesarefleeting

(samepatienton1daylater)45TransientTachypneaofNewbornat6hoursTheradiographontheleftshowshyperaeration,streakybilateralreticulonodularopacifications,prominentperihilarinterstitialmarkings,andmildcardiomegaly.Twodayslaterthereisnocardiomegalyandthepulmonaryparenchymalabnormalitieshavediminished.Thereisstillsomeperihilarstreakyopacities.at48hoursImagesfromEmedicine46

Group-BhemolyticStreptococcuspneumonia:Usuallyassociatedwithprematureruptureofmembranes.oftencoexistwithRDS,themimicappearance(clinicalandXfeatures)ofRDS（Hence,usallygivingantibioticstoallneonatesinthisconditionuntilbloodculturesarenegative.)47GBSNeonatalPneumoniaImagefromVirtualChildren’sHospital48陣發性呼吸急促及發紺腹部凹陷，患側胸部呼吸音減弱甚至消失，可聞腸鳴音

X片見患側胸部有充氣的腸曲或胃泡影、肺不張，縱膈移位Diaphragmatichernia---膈疝49六.Treatmentsupplementaloxygen—correcthypoxia

continuouspositiveairwaypressure(CPAP)

mechanicalventilation

---CPAP

Indication:whenFiO2>0.6,PaO2<50mmHgorTcSO2<85%

Pressure:4~10cmH2O,flow5L/min,32°C,humidity100%

---CMV