Weaning Approaches in Neonatal Ventilatory Care

1
Weaning Approaches in Neonatal Ventilatory Care

• D.T. Murai

2
Objectives

• Discussion of Goals and Concerns of Ventilation
  in the Newborn
• Discussion of Criteria for intubation and IPPV
• Discussion of Elements to consider in preparation
  of extubation
• Review of Literature

3
Weaning

• Also known as
• LIBERATION
• DISCONTINUATION

4
Goals of IPPV

• Provide supplemental oxygen
• Provide distending pressures
• Provide ventilation

5
Goals of IPPV

• Provide supplemental oxygen
• Use hoods, nasal cannula
• Provide distending pressures
• Use nasal CPAP, BIPAP
• Provide ventilation
• Provide mask bag ventilation
• Apneic ventilation

6
Apnea

• Treated with methylxanthines and CPAP and IPPV
• Stability essential for Normal organ function and
  development
• Brain
• Cardiovascular system
• Gut - nutrition

7
Concerns of IPPV in Newborn

• Intubation associated soft tissue trauma
• Intubation associated cerebral hypertension and
  intraventricular hemorrhage
• ETT assoc airway trauma, strictures
• Loss of glottal braking, atelectasis
• Excessive volume, airleak syndromes

8
Concerns of IPPV in Newborn

• 6. Loss of normal ciliary function, retention of
  secretions, need for suctioning
• Loss of cough, retention of secretions
• Postural changes inhibited, atelectasis
• Ventilator associated Pneumonia
• Pain and distress

9
Concerns of IPPV in Newborn

• Secondary concerns malnutrition
• Malnutrition related
• Infection
• Laryngotracheomalacia
• Delayed lung repair and growth
• Short
• Developmental Delays, Learning disabilities

10
Long Term Consequences of IPPV in Newborn

• Chronic Lung Disease
• Bronchopulmonary Dysplasia
• BPD

11
Concerns associated with BPD in Newborn

• BPD related chronic ventilation
• Diuretics, Fluid restriction - Growth delays
• Dexamethasone therapy - developmental delays,
  cerebral palsy, MR
• Tracheostomy

12
What should we do?

• Avoid intubation if possible- non invasive
  ventilatory support
• Early extubation when possible
• Avoid reintubation which affects brain, gums,
  teeth, throat, trachea

13
Criteria for Intubation

• Baby who is Extremely Small
• Baby who is Depressed
• Baby with Congenital anomalies
• Baby with Meconium in Amniotic fluid
• Baby with Need for immediate CPR
• Baby who has Apnea
• Baby with Hypercapnia

14
What do we know?
15
Weaning in the Adult

• Readiness Testing
• Respiratory failure has resolved (at least part)
• Respiratory muscle function has recovered
• Ready for trial of spontaneous breathing

16
Weaning in the Adult

• Readiness testing
• Subjective
• Objective - guidelines vs rigid rules - 30
• Between 65-85 of patients will pass trial of
  spontaneous breathing if satisfy readiness

17
Weaning in the AdultReadiness Criteria
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Weaning in the AdultReadiness Criteria

• Required (use by all researchers)
• PaO2/FiO2 gt151
• SaO2 gt91 in lt41Peep lt6 cmH20
• Hemodynamic stability (no or low meds)
• No active cardiac ischemia

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Weaning in the AdultReadiness Criteria

• Optional (used by some researchers)
• Rate lt36 bpm
• Spont Vt gt5ml/kg
• Neg inspir force lt -20 to - 25 cmH20
• f/Vt lt105 b/L min
• Hemoglobin gt8-10
• Core temp lt38.5
• Normal electrolytes
• CNS awake alert, arousable

20
Weaning in the AdultSpontaneous Breathing Trial
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Other Weaning Predictors

• Measurement of O2 and gas exchange
• Simple meas of respiratory load and muscle
  capacity
• Meas integrating multiple factors
• Complex meas requiring special equipment

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Weaning Predictors

• Measurement of O2 and gas exchange
• PaO2/FiO2
• PaO2/PAO2
• Dead space / Vd/Vt

23
Weaning Predictors

• Simple meas of respiratory load and muscle
  capacity
• Negative inspiratory force
• Resp system compliance
• Resp system resistance
• Minute ventilation
• Resp frequency
• Tidal volume
• Maximum voluntary ventilation
• Vital capacity

24
Weaning Predictors

• Measure integrating multiple factors
• f/Vt
• CROP

25
Weaning Predictors

• Complex measurements requiring special equipment
• Airway occlusion pressure
• P0.1/max insp presure
• Work of breathing
• Oxygen cost of breathing
• Gastric intramucosal pH

26
Weaning Predictors

• Negative inspiratory force
• Maximal inspiratory pressure
• Minute ventilation
• Airway occlusion pressure/max Pinsp
• CROP index
• Compliance, Rate, Oxygen, Pressure

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Weaning in the AdultIf Fails Readiness Criteria
28
Weaning in the AdultReadiness Criteria
29
Spontaneous Breathing Trial

• PSV lt7 cm H20
• CPAP
• Unassisted on T- piece
• 30 to 120 minutes or more
• 40 failure if extubated after readiness
  criterial alone

30
Criteria of Success of SBT

• SaO2 gt90 or PaO2 gt60 on FiO2 lt.50 or Pa/FiO2
  gt150
• Increase of PCO2 lt10 torr, pH lt 0.1
• RR lt35 bpm
• HR lt140 bpm or increase lt20
• BP gt90 sys lt160 mmHg or lt20 baseline
• Absence of signs of increased work
• Absence of signs of distress

31
Failure of SBT

• 30 may require more time
• Hypoxemia - unusual
• Depressed central drive - occasionally
• More often signs of increased drive
• Tachypnea
• Shallow breathing
• Muscle fatigue
• Cardiac dysfunction
• Psychologic

32
Weaning in the AdultIf Fails SBT
33
Weaning in the Adult
Failure
34
Weaning in the Newborn
Failure
35
Elements to Consider Prior to Extubation in
Newborn

• Mechanics
• Airway patent
• Lungs more compliant than chest wall
• Diaphragm function adequate
• Drugs
• Nutrition
• Mechanical disadvantage
• Central Drive Adequate
• Apnea
• Need for pain relief

36
Literature review

• What should be the rate, PIP,PEEP, TV before we
  are ready to extubate?
• How long from SBT?

37
Weaning in the NewbornsReadiness Criteria

• Not Uniform
• Rate lt6, lt15-25 bpm
• PIP lt12 -16
• PEEP lt 2 -5
• FiO2 lt.3- .35
• CNS No apnea

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LiteratureNeed for SBT

• Direct extubation rather than SBT
• Usually from low rates lt10 bpm
• J Perinatology 1989 Kim

39
Protocols?
40
Literature review

• Literature fails to provide uniform view
• Semin Neonatology 2002 Sinha

41
Literature review

• Automated protocols vs physician adjustment of
  pressure support
• No difference 76 v 85 v no protocols 73
• All weaned lt2 days
• Need for sedation lt 24h predicted failure
• JAMA 2002, Randolph, Ped Acute Lung Injury
  Network

42
Literature review

• Minute Ventilation Test vs Clinical Assess
• Shorter time to trial of extubation 8 vs 36h
• Extubation failure rate similar
• J Perinatol 2003, Gillespie

43
Literature review

• Test Respiratory muscle strength, respiratory
  load
• Airway occlusion method
• 30 failed, lower GA, Low max inspiratory
  pressures
• Unable to Predict - Similar with all groups
• Low GA, older PNA, better than max press
• Arch Dis Childhood Fetal Neonatal Edition 2002
  Dimitrious

44
Literature reviewPFT

• lt1000g infants
• Spontaneous expiratory minute ventilation
  lt125ml/min/kg during 2 hr of ETT CPAP
• 27 failed extubation, no diff in C or R,
• Lower rates 43 v 53, MV 240 v 309
• More time lt125 predictions better than Sats,
  TCCO2
• J Mat Fetal Neonatal Medicine 2004 Vento, et,al.

45
Literature review

• What should we do to enhance the likelihood of
  being successful after extubation?

46
Literature review

• Caffeine
• Non Invasive support

47
Literature reviewCaffeine

• lt32 week infants
• 3,15,30 mg/kg/d dose x 6 d
• Did not significantly improve extubation success
• Did reduce apnea at higher doses
• J Paediatric Child Health 2003, Steer

48
Literature Review

• Aminophylline
• Vent settings 12/2 f12 FiO2 lt.3
• Effective in lt 1000g lt 7days
• 72 control vs 28 treated
• Not effective gt1000g or lt1000g gt7 days no
  difference
• Pediatrics 1987, Durand

49
Literature reviewMethyl xanthines

• Reduced failure 53 lt1w
• Absolute reduction of 27
• NNT 13.7 but significant heterogenity in the 6
  RCT - control grp failures 20-100
• Cochrane 2003 Henderson-Smart

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Literature reviewMethyl xanthines

• One RCT
• Effective lt1000g , ltfirst week
• Not effective lt1000g, gtfirst week
• Not effective 1-1.25kg
• Cochrane 2003 Henderson-Smart

51
Literature Review

• Doxapram
• Extubated from f 6
• NCPAP
• No difference from controls
• Acta Paediatrica 1998 Barrington

52
Literature reviewNon invasive Pressure Support

• Nasal CPAP
• Any system acceptable and effective?

53
Literature reviewNCPAP

• Infant Flow System vs long prongs
• lt30weeks
• Success rate 62 vs 62
• Most common reason for failureapnea
• Pediatrics 2003 Stefanescu

54
Literature reviewNCPAP

• Hudson prongs vs single nasal prong
• Hudson 24 v 57
• Infants lt800g 24 v 88
• Cochrane 2001 Davis

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Literature reviewNCPAP

• Reduces adverse clinical events after extubation
  by 40
• apnea, resp acidosis, increased O2
• NNT 1 6
• Optimal level unknown
• Cochrane 2003 Davis and Henderson Smart

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Literature reviewNIPPV

• NISIMV vs NCPAP lt34w
• Extubated from 16/5 f15-25 FiO2 .35
• Success NISIMV 94 v NCPAP 60
• Ped 2001 Khalaf

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Other Therapies
58
Literature review

• Dexamethasone
• Since 1985 Multiple RCT show increases success of
  Extubation
• 1990s significant increase in Developmental
  Delay, Cerebral Palsy
• Pediatrics 1985 Avery

59
Literature review

• Dexamethasone
• 7 days of 0.5 or 0.2 mg/kg/d
• Similar changes to compliance, FiO2 need
• Pediatrics 2002 Durand

60
Literature review

• Aerosol Steroids vs IV Dexamethasone
• Success is Extubation lt7d after start
• 61 infants 761g, 25.7 w,
• Dxm 7/15, hi 3/16, med 1/15, low 2/15
• Inc BP, gluc, less wbc in T aspirates
• Ped Pulm 2003 Rozycki etal, Richm VA

61
Literature review

• gt3 weeks with BPD on Thiazides/Spirono
• Improved Compliance
• Reduced need for lasix.
• Decreased risk of death,
• Trend to decrease failure to extub in 8 w
• No effect - vent support, LOS, long term outcome
• Cochrane 2002 Brion

62
Literature Review

• Nebulize racemic epinephrine
• No evidence supporting or refuting the use
• Cochrane 2002 Davies and Davis

63
Literature review

• End tidal during mech and spont vent
• 25 in icu capnography
• Peak values of exhaled co2, rate of rise, area
  under curve
• Ped Pulmonology 2001 Hsieh

64
Literature reviewNIPPV

• Pulmonary function testing
• Compliance gt0.5ml/kg/cm and Resistancelt70 cmH/l/s
  
• 80 successful extubation
• Pediatrics 2001 Khalaf
• Ped 2001 Khalaf

65
Literature review

• Ncpap
• NINSIMV Vent12/6/f12 v NCPAP 6
• lt35 lt18b/m extubated amniophylline
• After 12 hours SIMV rate 12
• Success lt70 CO2, lt.7 FiO2 no
  signs apnea x 3d
• Extubation average 7.6days
• 4/27 vs 12/27 most apnea, hyperCO2
• Ped 2001 Barrington

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Literature ReviewOne Article's Summary

• NCPAP
• NIPPV
• Methylxanthines
• IV Dexamethasone
• Chest physiotherapy no effect on atelectasis,
  need q1-2h
• Paediatric Resp Rev 2004 Halliday

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Summary

• Weaning or Liberation from Mechanical Ventilation
  is still part Science and a lot of Art
• The differences in Adults and Neonates are due to
  differences in physiology, anatomy and degrees of
  consequences
• When you are at KMCWC remember little a babies
  are not little adults