TY  - CHAP
M1  - Book, Section
TI  - IVH, PVL, and Hydrocephalus
A1  - Malcolm, William F.
Y1  - 2015
N1  - 
T2  - Beyond the NICU: Comprehensive Care of the High-Risk Infant
AB  - Intraventricular  hemorrhageDefinitionIntraventricular  hemorrhages  (IVH)  are  bleeds  in  the  subependymal  germinal  matrix  and  ventricular  system  of  the  brain.IncidenceRates  of  IVH  in  very  preterm  or  very  low  birthweight  (VLBW)  infants  (<32  weeks'  gestation  or  <1500  g)  vary  between  20%  and  25%,  with  about  6%  to  7%  suffering  from  severe  IVH  (grade  3  or  4).PathophysiologyThe  germinal  matrix,  which  is  lining  the  lateral  ventricles,  is  the  site  of  glial  and  neuronal  precursor  cells  and  involutes  by  34  gestational  weeks.  The  rich  microvasculature  of  this  temporary  structure  is  poorly  supported  by  connective  tissue  and  extremely  fragile.In  addition,  cerebral  circulation  in  the  preterm  infant  is  often  pressure  passive,  ie,  cerebral  blood  flow  varies  with  systemic  blood  pressure,  due  to  immature  cerebrovascular  autoregulatory  mechanisms.  Any  disturbance  in  cerebral  blood  flow  or  an  increase  in  cerebral  venous  pressure  can  lead  to  rupture  of  the  capillary  network  with  bleeding  in  the  germinal  matrix  and  possible  extension  into  the  ventricular  system.Venous  infarction  in  the  periventricular  white  matter  area  (periventricular  hemorrhagic  infarction  [PVHI])  may  follow  secondary  to  impaired  drainage  and  thrombosis  of  the  medullary  veins  due  to  compression  of  distal  terminal  veins  by  an  intraventricular  hematoma.Inflammatory  cytokines  and  reactive  oxygen  species  are  also  important  mediators  in  the  mechanisms  of  microvascular  disruption,  cerebral  blood  flow  dysregulation,  and  periventricular  reperfusion  injury.Finally,  obstruction  of  cerebrospinal  fluid  (CSF)  flow  can  lead  to  progressive  ventricular  dilation  (see  the  Hydrocephalus  section)  with  pressure-induced  infarction  of  adjacent  white  matter  and  subsequent  atrophy.Risk  factorsThe  risk  of  IVH  and  level  of  severity  increase  with  lower  gestational  age  and  lower  birthweight.Risk  factors  are  related  to  conditions  that  can  lead  to  either  fluctuating,  increased  or  decreased  cerebral  blood  flow  or  increased  cerebral  venous  pressure.They  are  also  associated  with  systemic  inflammation.Antepartum  conditions  includeAbsence  of  antenatal  steroids  administrationMaternal  hemorrhageChorioamnionitis  or  maternal  infectionsPeripartum  conditions  areRequirement  for  neonatal  transportVaginal  deliveryVigorous  resuscitationPostnatal  conditions  includeSevere  respiratory  distress  syndrome,  asynchronous  ventilator  breathing  pattern,  hypoxemia,  hypercarbia,  hypocarbia,  pneumothorax,  pulmonary  hemorrhage,  patent  ductus  arteriosus,  acidoses  requiring  sodium  bicarbonate,  hypotension  requiring  inotropes,  hypertension,  sepsis,  and  seizures.Furthermore,  candidate  genes  that  may  modulate  the  risk  for  IVH  due  to  their  involvement  in  the  processes  of  inflammation,  hemostasis,  or  vascular  stability  are  currently  being  investigated.Clinical  presentationSigns  and  symptoms90%  of  IVH  occur  within  the  first  72  hours  of  life  with  progression  over  the  following  week.  The  majority  of  infants  will  be  asymptomatic  and  diagnosed  following  screening  cranial  ultrasound.Signs  and  symptoms  may  be  subtle  and  include  changes  in  level  of  consciousness,  cardiorespiratory  pattern  (apnea,  bradycardia,  hypotension),  movement  quantity  and  quality,  muscle  tone,  and  eye  position/movement.  In  severe  cases,  stupor  and  coma,  a  sudden  drop  in  blood  pressure,  nonreactive  pupils,  decerebrate  posturing,  flaccidity,  and  seizures  may  be  present.  Distension  of  the  anterior  fontanelle  or  cranial  sutures  may  also  be  observed.Any  unexplained  decrease  in  hematocrit  or  failure  to  increase  the  hematocrit  following  blood  transfusion  should  also  raise  the  concern  for  a  possible  intracranial  bleed.If  lumbar  puncture  is  performed  in  the  context  of  suspected  sepsis,  CSF  can  reveal  the  presence  of  red  blood  cells,  high-protein  content,  and  low  glucose  level.Condition  variabilityIVH  are  graded  in  severity  according  to  Papile  classification  system.Grade  1:  Bleeding  ...
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/18
UR  - accesspediatrics.mhmedical.com/content.aspx?aid=1105545276
ER  -