Management of Respiratory Disease in the Term Infant

Transcription

1 Management of Respiratory Disease in the Term Infant David Tingay 1. Neonatal Research, Murdoch Children s Research Institute, Melbourne 2. Neonatology, Royal Children s Hospital 3. Dept of Paediatrics, University of Murdoch Children s Research Institute, 2017

2 Respiratory support of the term infant is more interesting Aim for NIV as soon as practical What is the pathophysiological process? Disease State? Mechanical State? Regional? Ti & Te Where possible target V T not PIP Ventilation Approach Modality* Atelectasis C RS, R RS N Short HVS CMV/ HFOV Normal Lung C RS N, R RS N Homogeneous Short Cautious HVS+P CMV/ HFOV Gas Trapping C RS N, R RS Normal NVS CMV Hypoplasia C RS, R RS N Heterogeneous Long LVS HFJV/ HFOV In complex mixed regional lung pathophysiology the correct approach is usually dictated by the current primary problem strategy needs frequent re-evaluation. Normal - Long Short N or LVS+P N or LVS HFJV/HFO V/CMV HFJV P = positioning, VS = Volume Strategy; H = high, N = normal, L=low 2

3 Ventilator settings for the term infant are not the same as the preterm Tau = C RS x R RS 3

4 Time is an important factor in volume and oxygen change in the term infant Miedema et al ICM 2012 Tingay PhD

5 The Congenital Diaphragmatic Hernia lung Respiratory support for Bilateral Heterogeneous Hypoplasia for many, the management of the newborn with CDH is more emotional than scientific. Glick, Irish & Holm Clin Perinatol 1996 unlike the other neonatal pulmonary diseases, CDH does not represent a recruitable lung and attempts to use a high mean airway pressure are likely to cause pulmonary damage. Kotecha et al Eur Respir J 2012 Bohn AJRCCM

6 CDH: Cardiac or respiratory disorder? 1. Milnarone 2. Adrenaline/Dobutamine 3. Noradrenaline 4. Steroids 5. ECMO 1. Inhaled Nitric Oxide 2. Sildenafil 3. Milnarone 4. PGE1 5. Other agents/ecmo 1. Conventional Ventilation 2. High frequency Oscillatory Ventilation 3. High Frequency Jet Ventilation Adapted from Kinsella J Peds

7 CDH is not a static problem understanding the baby Poor Oxygenation High CO 2 Acid build Up Aggressive Ventilation Surgery Loss of lung elasticity Large lungs Pulmonary Hypoplasia Small Lungs Ventilator Induced Injury VILI 1. Cautious use of pressure: P aw <15 cmh 2 O PEEP 4-6 cmh 2 O PIP <25 cmh 2 O 2. V T Target? V D & Alveolar V T unknown What impact will my ventilator settings have on RV and LV Function? 7

8 Different diagnoses but are they different diseases? Term Blood Aspiration Preterm Pulmonary Haemorrhage Term Congenital Pneumonia De Luca Lancet Rep 2017 Suppl Material 8

9 The Montreux definition of Neonatal Acute Respiratory Distress Syndrome Diagnostic criteria for a new neonatal disease The Neonatal ARDS Collaborative Project (ESPNIC/ESPR) D De Luca, AH van Kaam, DG Tingay, SE Courtney, O Danhaive, VP Carnielli, LJ Zimmermann, MCJ Kneyber, P Tissieres, J Brierley, G Conti, JJ Pillow, PC Murdoch Children s Research Institute, 2017

10 Biology of ARDS Red circles/squares = proinflammatory mediators, ROS, proetases Red shading = sits of ARDS-mediated cellular injury Orange balls = intraalveolar plasma proteins Phosplipase-driven surfactant dysfunction (spla2) 10

11 Does Neonatal ARDS exist? 32 publications with term neonatal ARDS from 1989 All with criteria that meet PALICC but occurred in perinatal period 11

12 Proposed Pathophysiology of Neonatal ARDS Aetiology Direct injury to lung parenchyma Extra pulmonary process Perinatal or postnatal Lung inflammation Secondary surfactant dysfunction Impaired compliance Increased shunt Alteration of local lung defences 12

13 The Montreux definition Oxygen impairment with decreased EEV needing Positive Pressure support to recruit alveoli Respiratory failure not fully explained by lung oedema due to heart failure 0-44 weeks PMA or up to 4 weeks postnatal age 5 Criteria that must be met: Timeframe: Acute onset (<7d) of known or suspected insult (including perinatal) 2. Exclusion: RDS, TTN, congenital anomalies and genetic disorders of surfactant dysfunction 3. Imaging confirmation: Diffuse bilateral irregular opacities on imaging (excludes primary RDS and focal events e.g. localised pneumonia and bronchiolitis) 4. Origin of Oedema: Not cardiac 5. Oxygenation defect based on OI 13

14 Montreux Definition Specific points: Perinatal triggers allowed Does not exclude preterm infants Does not exclude infants managed with NIV OI ideally defined using arterial blood gas but TcO 2 allowed SpO 2 concentrations not to be used to asses oxygenation due to variable oxygen dissociation curve in neonates (eg SpO 2 /FiO 2 ratio) Preductal measures of oxygenation to account for comorbidity of PPHN 14

15 Different diagnoses same characteristics = same disease 1. Acute Onset 2. No RDS, TTN etc 4. Oedema not cardiac* 5. Severe oxygenation deficit Term Blood Aspiration Preterm Pulmonary Haemorrhage Term Congenital Pneumonia 3. Diffuse bilat irregular opacities/infiltrates De Luca Lancet Rep 2017 Suppl Material 15

16 Summary Term lung diseases are more diverse and requires greater understanding of respiratory physiology The concepts of respiratory support are the same as the preterm infant but absolute values are not Collectively diseases of the term infant are common but specific diseases are rare relative to the preterm infant A focus on pathophysiological processes rather than specific disease entity may provide a better method of defining term lung disease Opportunity to better evaluate new therapies and apply existing therapies established in older populations 16