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Minimizing Lung Damage During

Respiratory Support

Care of the Sick Newborn 2015

Eduardo Bancalari MD

University of Miami

Miller School of Medicine

Jackson Memorial Hospital

University of Miami Jackson Memorial Medical Center

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20

40

60

80

100

%

23 24 25 26 27 28

Gestational Age (wks)

NICHD NETWORK

Bronchopulmonary Dysplasia (O2 at 36 wks PMA)

Years 2003-2007

What Can Damage The Immature Lung

• Over distension

Excessive VT : PIP – PEEP

Excessive FRC: PEEP, gas trapping

Prolonged inspiratory time

• Low volume, loss of FRC: Insufficient PEEP

• Oxidative damage

• Infection: Pulmonary, systemic

• Increased PBF-PE : PDA, excessive fluid administration

• Inadequate conditioning of the inspired gas:

Temperature, humidity

How Can We Protect The Immature Lung ?

• Accelerate Maturation: Antenatal steroids

• Surfactant Replacement Prophylaxis vs Rescue?

• Gentle Ventilation Appropriate tidal volume / Volume target/ HFV Adequate PEEP Patient Triggered Ventilation

Permissive hypercapnia?

• Avoid High Inspired Oxygen Concentrations

• Avoid Invasive Ventilation: CPAP , N-IPPV

Respiratory support strategies to prevent BPD • Respiratory support during resuscitation : Ventilation,

Oxygen • NCPAP vs intubation after birth • NIPPV vs IPPV in RDS • Synchronized ventilation • Permissive hypercapnia • HFV: HFO, HFJV • Volume targeting • Oxygen targets

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Does variation in respiratory management in NICUs

explain differences in CLD? Van Marter. Pediatrics 2000, 105,1194-1201

Compared Columbia NY with 2 Boston hospitals.

Infants < 1501g in 1991 - 1993.

Boston Columbia

n=341 n=100

Ventilation 75% 29%

Surfactant 45% 10%

Oxygen at 36 wks 22% 4%

Boston Columbia

n=341 n=100

Ventilation 75% 29%

Surfactant 45% 10%

Do differences in delivery room intubation explain different

rates of BPD between hospitals?

Gagliardi, L et al. Arch Child Fetal Neonatal Ed. 2011;96:F30-F35

IPPV >24h = OR for BPD 2.4

IPPV >7d = OR for BPD 14.9

NCPAP vs. IPPV BPD or Death

Fischer S H, and Buhrer C, Pediatrics Nov 2013

Death/BPD IPPV Surfactant CPAP MV-Surf CPAP MV-Surf CPAP MV-Surf

COIN 25-28 wks

34% 39% 58.7% 100% 38% 77%

SUPPORT 24-28 wks

49% 54% 83.1% 24.8 d

99.7% 27.7d

67% 99%

VON (CPAP) 26-30 wks

31% 37% 52% 96% 46% 99%

VON (ISX) 29% 37% 59% 96% 98% 99%

Early CPAP vs. IPPV in extremely low gestational age newborns

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fan

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500-599 600-699 700-799 800-899 900-999 1000-1099 1100-1199 1200-1250 <1250

Birth weight (g)

Distribution of infants (%) into respiratory care groups by birth

weights

CPAP-started (% of total) CPAP-success (% of CPAP-started) CPAP-success (% of total)

Adapted from Ammari et al. J Pediatr. 2005; 147(3): 341-347

Is Nasal Ventilation a Better

Alternative?

• Possible mechanisms of action:

– Increase in Vt and Ve

– Upper airway stimulation may reduce apnea

– Higher mean airway pressure: Better lung stability and

gas exchange

– Reduced dead space: Clears exhaled gas from proximal

airway

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Nasal Ventilation

Physiologic effects

• Decreases apnea

• Improves ventilation- gas exchange

• Increases lung volume- improves

oxygenation

• Decreases respiratory effort

• Decreases chest wall distortion

Non Invasive Respiratory Support - Conclusions

Many very premature infants can be managed with NCPAP or NIPPV from birth

It is difficult to predict which infants will fail and require intubation and mechanical ventilation

Success depends on gestational age, degree of lung disease, respiratory drive, and team’s attitude and skills

Use of NIPPV instead of CPAP may reduce the number of infants that need intubation and shortens the duration of MV

Early NCPAP or NIPPV may delay administration of surfactant in infants with RDS and worsen their evolution

The evidence that non invasive respiratory support improves short or long term outcome in ELBW infants is not very compeling

Depressed - Poor resp effort

ET tube IPPV

Surfactant if RDS

When stable extubate

to NCPAP or N-IMV

Active - Good resp effort

Approach to VLBWI in the DR

Start NCPAP or N-IMV

Deterioration,

Increasing FiO2,

PaCO2, Apnea

ET tube-IPPV-

Surfactant if RDS

When stable extubate

to NCPAP or N-IMV

Stable-Continue

NCPAP

Newer Modalities of Mechanical Ventilation

• Patient Triggered (Synchronized Ventilation) S-IMV Assist control Pressure support Proportional assist ventilation (PAV) NAVA (Neurally adjusted ventilatory assist)

• Volume targeted ventilation

• Experimental:

Closed Loop FiO2 control

Continuous flow or distal tracheal ventilation

Targeted minute ventilation

CONTROLLED IPPV

(Apnea or M. Relaxants)

IMV - SIMV - AC - PSV - PAV

NON INVASIVE SUPPORT

Nasal CPAP - Nasal IPPV

Ve

ntilato

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nc

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ASSISTED VENTILATION

• Duration of ventilation

Synchronized vs. Conventional

Ventilation

Greenough and Dimitriou

Cochrane Database 2008

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Firme SRE et al. Pediatr Pulmonol 2005;40(1):9-14

IMV vs. SIMV and Hypoxemia in Preterm Infants 20cmH2O

Paw

0 16 ml

VT

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0.8 s

SIMV (20 b/m)

SIMV (10 b/m) + PS 20cmH2O

Paw

0 16 ml

VT

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Time (Days)

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Ven

tila

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Dep

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%)

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100SIMV+PS

SIMV

Time to extubation

On MV at day 28

SIMV 69%

SIMV+PS 47%

Reyes et al. Pediatrics October 2006

Ventilator and Oxygen Dependency

700-1000g BW strata SIMV SIMV+PS

Days on MV (median, 25thand 75th percentile)

25 (8-47)

15 (6-23)

Days on oxygen (median, 25th and 75th percentile)

58 (44-87)

41 (34-51)*

On oxygen at 36w PMA 38

17%

Reyes et al. Pediatrics October 2006

*P 0.034

Pressure Support Ventilation

• Patient maintains spontaneous respiratory effort

• Duration of inspiration and expiration determined by the patient

• Spontaneous breaths can be unloaded as necessary to maintain Vt and Ve

• Volume loss can be prevented by few larger SIMV breaths

• Weaning is accomplished by gradual reduction of the pressure support

Limitations of PTV

• Low Sensitivity of trigger

Lack of trigger

Trigger delay: Mechanical breath extending

into expiration causing active expiration

• Excessive sensitivity to trigger artifacts:

Auto triggering

• Early termination, mechanical inspiration too

short: insufficient tidal volume

• Added dead space:CO2 retention

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Volume Targeted

Ventilation

No. of studies

No. of Infants

Statistical method Effect size

Duration of IPPV (log data)

5 381 Mean Difference (IV,

Fixed, 95% CI) -0.08 [-0.16, -0.00]

Wheeler K et al. Cochrane Database of Systematic Reviews 2010, Issue 11.

Volume-targeted vs. pressure limited ventilation: Duration of IPPV

VTV versus PLV: Death or BPD (36 weeks)

Significant difference Death or BPD 32% v 43%

RR 0.73 95% CI 0.57 to 0.93, NNT 8

Wheeler K et al Neonatology 2011

VTV versus PLV: Pneumothorax

Significant difference Pneumothorax 4% v 10%

RR 0.46, 95% CI 0.25 - 0.84

Wheeler K et al Neonatology 2011

VTV versus PLV: Grade 3/4 IVH or PVL

Significant difference PVL or grade 3-4 IVH 8% v 16%

RR 0.48, 95% CI 0.28 - 0.84

Wheeler K et al Neonatology 2011

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Peng WS et al. Arch Dis Child Fetal Neonatal Ed 2013;0:F1–F8. doi:10.1136/archdischild-2013-304613

BPD

Volume-targeted ventilation is more suitable than pressure-limited ventilation for preterm infants: a systematic review and meta-analysis

VG

Volume targeted ventilation

• Rationale: More consistent Vt – avoids excessive volumes

Automatic weaning of pressure

Shorter duration of mechanical ventilation

Reduces duration of hypoxemia episodes

Reduces death or BPD

• Limitations: Leaks around the endotracheal tube

Poor estimation of Vt:

Different inspiratory and expiratory Vt with leaks

Volume loss in the ventilator circuit: Vt delivered by ventilator larger than patient Vt

Cools F, Henderson-Smart DJ. Cochrane Database of Systematic Reviews 2009

OXYGEN DAMAGE

Contrasting light microphotographs of lung parenchyma of rats exposed to room air and O2

Shaffer SG, et al. Pediatr Res. 1987;21:14-20.

Hyperoxia Disrupts Alveolar Development

Room air O2

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Are New Ventilation Modalities

Associated With Better

Outcome?

TEN YEAR TRENDS IN NEONATAL ASSISTED VENTILATION

Rich W, et al: Journal of Perinatology 2003, 23:660

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Unadjusted annual rates for GA <29 weeks (n = 1441)

BPD Severe BPD

Smith et al. J Pediatr. April 2005; 146(4):469-473

“Miami Neonatology 2015” &

Workshop:

“Advances in Neonatal Respiratory Care”

November 11 – November 14, 2015

Fontainebleau, Miami Beach

Speakers Topics

http://www.miamineonatology.com

39th Annual International Conference

• Robert “Bob” Christensen, MD

• Scott C. Denne, MD

• Terrie Eleanor Inder, MD, M.B.CH.B.

• Julie R. Ingelfinger, MD

• Shahab Noori , MD, RDCS

• Saroj Saigal, MD, FRCP

• Pablo Sanchez, MD

• Umberto Simeoni, MD

• Sergio Stagno, MD

• Anton H van Kaam, MD, PhD

• Myra Wyckoff, MD

• Jill L. Maron, MD, MPH

• Thrombocytopenia in the NICU

• Evidence-based NICU transfusion guidelines

• Growing extremely premature infants in the NICU

• Providing enteral nutrition to extremely premature

• Influence of the environment and experience on brain development

• To MRI or not to MRI at term for the preterm infant

• Acute kidney injury (AKI) in the neonatal period

• The neonate with CAKUT

• Diagnosis and Management of Neonatal Hypotension and Shock

• Pathophysiology of P/IVH in the very preterm neonate

• Lifetime perspectives of former very premature infants

• Quality of life of former premature infants

• Antimicrobial Stewardship in NICU

• Early nutrition and the risk for long term disease

• Extreme preterm birth and medical decision making

• Perinatal viral infections, new developments on an old challenge

• High frequency ventilation

• Lung protective ventilation using conventional modes

• 2015 New Neonatal Resuscitation Guidelines

• Use of monitoring and Epinephrine in the DR