mira cradle.ppt

a device for therapeutic hypothermia

1. Mira cradle applications
Dr. SACHIN SAKHARKAR
Surya hospital NICU
7/29/2022

2. Objectives
•Therapeutichypothermia(TH)
•SelectioncriteriaforTH
•Contraindication
•Monitoringoftheinfant
•SystemiccareofpatientsduringTH
•MiraCradle
•Re-warming
•THpriortoandduringtransport
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3. Introduction
•Neonatalhypoxicencephalopathyisaneurological
emergency
•Peripartumasphyxiaaffects3to5newbornsper
1000livebirthswithsubsequenthypoxicischemic
encephalopathy(HIE)in0.5to1per1000live
births(Levene1986)
•NGunn(1997):60%LTNDif:
HIE
Seizures

4. •Biphasic nature of cell death GluckmanPD, et al 1992
•Primary neuronal death (cell hypoxia/primary energy
failure)
•Latent period –6 hours
•Secondary phase –delayed neuronal death begins

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9. History
•1803 “Russian Method of Resuscitation” consisted of
burying the victim of a cardiac arrest in snow hoping
for ROSC
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10. •JamesMillerandBjornWestininthe1950s
developedascientificrationalefortheuseof
hypothermiain"asphyxianeonatorum”infirstcase
series
•In1959,Bensonetal,caseseriesof19patientpost
cardiacarrest

11. •Animal Studies
•Preservation of architecture in cortex of cooled fetal
sheep (Gunn et al J of ClinInv 1997)
•Control Cooled

12. •MarianeThorensen-Intrigued by stories of children
who fell through Norwegian ice and suffered
prolonged drowning in iced water emerged with
preserved cerebral function

13. •Infants≥36weeksgestationalagewithmoderateto
severeneonatalencephalopathy
•Intervention-Braincoolingvsconventionaltreatment
•Outcome:
Death
Neurodevelopmentaldisability
Combinedoutcome

14. •THisdefinedasmoderatehypothermiawhenwhere
thecorebodytemperaturemeasuredbyesophageal
orrectalprobeiscooleddownto33.0–35°Cfor72h
followedbyslowre-warming(0.2–0.5°C/h)

16. Total body hypothermia for neonatal encephalopathy
TOBY-n=325
•Cooledto33C-34Cfor72hoursorusualcare.
•Primaryoutcome:deathorsevereneurodevelopmental
disabilityat18monthsoccurredin53%oftheusualcaregroup
and45%ofthecooledgroup([RR]0.86[0.68–1.07],P=.17).
•Predefinedsecondaryoutcomes:survivalwithoutdisabilities
significantlyhigherinthecooledvs.theusualcaregroup.The
rateofCPwaslow,improvedmentalandpsychomotorindices
werenotedinthecooledvs.theusualcaregroup(P<.05)
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23. Inclusion Criteria
Infant>36weeksgestationandleastone
•Apgarscoreof≤5at10minutes
•Continuedneedforassistedventilationat10mins
•Acidosis(umbilicalcordphorarterialph<7.00)
•Basedeficit≥16mmol/L
•Moderatetosevereencephalopathywithorwithout
seizuresorthepresenceofoneormoresignsin3of6
categoriesonthechart(modifiedSarnatscore)

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26. ExclusionCriteriaforTherapeuticHypothermia:
•SevereIUGR<1750grams
•Severecongenitalanomalies/geneticsyndromes/
metabolicdisorders
•Majorintracranialhemorrhage
•Overwhelmingsepsis
•Uncorrectable,clinicallyrelevantcoagulopathy
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28. MIRA CRADLE

29. •IthasbeendevelopedincollaborationwithCMC,
Vellore
•Components
Cradle
Phasechangematerial
Conductionmattress
•Associatedequipments
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30. •Cradle
Exoskeleton of the device
Provides insulation to the PCM mattress from
ambient temperature
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31. •PhaseChangeMaterials(PCMs)arespecialthermal
energystoragematerials
•Ituseschemicalbondstostoreandreleaseheat
•Properties-Consistency
ConstantTemperature
HighLatentheatenergystoragecapacity
•TwoPCMs
FS21
FS29

33. FS29
•Nominalfreezingandmeltingtemperatureof29°c
•Itretainsitsformandshape
•Sixunitsareprovided
•Chargingtime8-10hourswhenstoredinbottompart
oftherefrigerator

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•Usedinmaintainingandsustaininghypothermia
•Threeunitstobeused
•Notrequiredtobereplacedduring72hoursprocess
•Otherthreeunitsshouldbekeptonstandby

35. FS21
•Nominal freezing and melting temperature of 21°c
•It retains its form and shape
•Two units are provided
•Charging time 6-8 hours when stored in bottom part
of the refrigerator

36. •Used in conjunction with FS29
•Used to induce hypothermia
•Used to control temperature ( when newborn temperature
starts drifting above 33.8 c)

37. Conduction mattress
•Gel based, wt-1.2kg
•Enhances heat transfer
•Provides smooth surface for newborn to lie
•Store-room temperature
•Flat and uniform before use

38. Use
Beforeuse
•Cleancomponentswithhospitalapproved
disinfectant
•RemoveclothbagandensurePCMsarehardand
rigid
•EnsurethatPCMsandconductionmattressarenot
leaking
•EnsurethetemperatureofFS29

39. Checking FS29
•Should feel hard and rigid
•Temperature indicator
•Three units to be placed at the bottom
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42. Preparing associated equipments
•Thincleanbedshit
•Warmer-switchofthewarmerandlatertobeused
inmanualmode
•Rectalprobe-insert3-5cmwithintherectumto
monitorcoretemperature
•Multiparameter-settemperaturealarmlimitsof33.2-
33.8c
•NICUtemperature24-30C

43. Inducing hypothermia
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44. Sustaining hypothermia
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46. Re-warming phase
•Target re-warming rate -0.2°C/hour
•Target re-warming temperature-36.5°C
•During re-warming phase, do not remove infant from
Mira cradle
•Use warmer in manual mode only

47. Steps
•Covernewbornwithsheet
•Turnonwarmerwith10-30%output
•Recordtemperatureeveryhour
•Ifrateishigher-switchofthewarmer
•Oncethetemperatureis36.5°C
removeinfantfromMiracradle
•Monitortemperaturefornext8hours

48. Monitoring
Heart rate Hourly
Respiratory rate Hourly
Blood pressure Hourly
Spo2 Hourly
Rectal temperature
Skin temperature Continuous
Urine output 6 hourly
Skin redness/breaks 4 hourly

49. Respiratory management
•Hypocarbiaandhyperoxiahaveshowntoincrease
neuronalinjuryinasphyxiatednewborns
•Thoresenetal.suggesttoaimforPaCO2levelsof41–50
mmHg
•Effectsofwholebodyhypothermiaonlungmechanics
•hypothermiacausesaleftwardshiftinthehemoglobin-
oxygendissociationcurve

50. Circulatory management
•EffectsofTHonheartarebradycardiaand
decreasedcardiacoutput
•Sinusbradycardia-sloweractivityofatrial
pacemakerandintracardiacconduction
•Cardioprotectiveeffect
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51. •Effect of TH on mesenteric circulation is unclear
•Enteralnutrition is generally delayed until rewarming
•HIE itself cause renal failure or SIADH resulting in
oligo-anuriawhich may necessitate fluid restriction to
avoid volume overload and brain edema
•TH may be associated with “cold diuresis” in the
adult

52. Hematological aspects
•TH is also known to cause platelet dysfunction, and
thrombocytopenia and
Electrolyte monitoring
•Dilutionalhyponatremia
•Intracellular potassium shift
Glucose management
•Hyperglycemia due to stress hormones followed by
•Hypoglycemia due to depleted liver glycogen

53. Subcutaneous fat necrosis
•THhasassociationwithSCFN
•Self-limitedcondition
•SCFNusuallyappearswithin1
st
weekoflife,
hypercalcemiamayevenoccurmonthslater
•Maycauserefractoryhypercalcemiasometimesresulting
innephrocalcinosis

54. Drug metabolism
•TH causes delayed metabolism of drugs -
phenobarbital, morphine, and vecuronium
•Gentamicinmetabolism has been studied during TH
and 36 h dosing interval has been found to result in
acceptable trough levels with desired efficacy

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56. Stop cooling before 72 hours if
•Persistent hypoxemia with 100% Fio2
•Life threatening coagulopathy
•Arrhythmia requiring medical treatment
•Decision on withdrawal of care
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57. Maintenance
Storage
•Storeinrefrigerator
•Chargefor8-10hours
•Donotfold/bend/distort
•Storeonflatsurface
•Donotstackoneaboveother
•Whennotinuse,shouldbekeptinclothbag
provided

58. Periodiccalibrationcheck
•Onceamonth,crosscheckindicatortemperature
manually
•Temperaturedifferenceof1Cisacceptable
•Ifdifferenceis>1c,thencontactcompanyfor
replacement
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59. Periodicreplacement
•Tobereplaced3yearsfrom1
st
useorwhenfound
damaged
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60. Cooling during transport
•passive cooling allows safe controlled cooling to begin prior to
the arrival of the baby in the cooling centre
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63. Thank you