Chronic PH a spectrum illness Enhanced Precision in care of Neonate - - PDF document

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Chronic PH – a spectrum illness

Patrick McNamara Professor of Paediatrics & Internal Medicine Senior Associate Scientist, University of Iowa

Enhanced Precision in care of Neonate with cPH!

• Reliability of clinical assessment
• Optimal approach to diagnosis
• Therapeutic precision
• Preventative approach

Case

• Ex-24 week twin
• Hx Meconium Inspissation

[stoma], PDA –medical therapy,

• nCPAP FiO2 0.3
• Day 84 Screening TnECHO

TnECHO: RV systolic pressure 85 mmHg, mod dilated RV

• Ex-22 week infant
• Hx prolonged ventilation

HFJV, rec sepsis

• Tracheostomy/G-tube
• sIMV 30/5, FiO2 0.25
• Day 104 Screening TnECHO

TnECHO: Normal

Chronic Pulmonary Hypertension – Spectrum illness

Dysregulation of pulmonary vascular bed and/or right ventricular failure Incidence 28% in patients with CLD at 36 weeks

Weismann 2017 J Peri

Mortality rate up to 38% in severe BPD

Khemani 2007 J Pediatr

Challenges

• 1. Impact of confounding illnesses
• 2. Variable adaptive response of RV to elevated afterload
• 3. Echo limited to subjective appraisal of pressure and function
• 4. It doesn’t exist or it doesn’t matter

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Evaluation of Chronic Pulmonary Hypertension

• How reliable are methods of evaluation?
• How precise are diagnostic methods?
• Are screening thresholds temporally appropriate?
• Is longitudinal monitoring consistent?

Perinatal Factors

Gestation Chorioamnionitis Resuscitation Sepsis

Postnatal Factors

Lung disease Ventilation, Oxygen PDA Sepsis/NEC

36 weeks

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Perspectives: Echo Screening at 36 weeks

Altit et al 2018

Survey of management of chronic PH in premature babies in Canadian Neonatal Network and National Research Network NICUs

Michelle Baczynski, Emer Finan, Patrick McNamara, Edward Bell, Amish Jain

• Response from 37 tertiary NICUs [29/44 CNN, 9/16 NRN]
• 57% centers routine echo screening for cPH [almost always ‐

respiratory support at 36 weeks CGA (71%)]

• Only 17% (5 sites) performed RH catheterization
• 86% reported use of pulmonary vasodilators

Case

• Preterm infant with antenatal diagnosis possible coarctation of the

aorta and omphalocoele

• Gestational Age: 28+3
• Birthweight: 1105g
• Initial course unremarkable, CPAP in room air x 5 days then low

flow 50mL/min.

Cardiology: Serial echo – coarctation ruled out TnECHO…..

Course Prior to TnECHO Assessment

Postnatal Day PDA 2.4mm

2 6 16

PDA 1.6mm PDA 1.1mm Low Flow 30‐ 50mL/min Baseline HR 120s CPAP FiO2 0.21 Progressive respiratory decompensation Intubation; FiO2 40‐50%

41

FiO2 80% BP 95/60 well sedated

48

Baseline HR ⇡ gradually to 180s; irritable

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Dilated Right Heart

Dilated RA & RV Dilated main PA with mild PI

Severe Pulmonary Hypertension & low CO

RVSp at least 120mmHg + RAp Systolic BP = 95mmHg Paradoxical septal motion Very low left ventricular output – 70 ml/min/kg

Clinical Course

• Respiratory decline until FiO2 1.0 despite appropriate recruitment, normal CO2,

sedation and muscle relaxation

• Pulmonary vasodilator therapy initiated sequentially:

– Inhaled nitric oxide – Milrinone titrated up using echo guidance to a max dose of 0.9mcg/kg/min – IV prostacyclin

• Right heart dysfunction with systemic hypotension treated with dobutamine,

vasopressin, hydrocortisone

• Ongoing progressive desaturation [70‐75%] and right heart dysfunction; on

postnatal day 56 ICU support withdrawn with parents consent

Postnatal Day Cardiology: Serial echo – coarctation ruled out Progressive respiratory decompensation TnECHO….. PDA 2.4mm 40% R ⇢ L

2 6 16

PDA 1.6mm 30% R ⇢ L PDA 1.1mm 40% R ⇢ L Low Flow 30‐ 50mL/min

41

Intubation; FiO2 40‐50% Baseline HR 120s

48

FiO2 80% BP 95/60 well sedated Baseline HR ⇡ gradually to 180s; irritable

Course Prior to TnECHO Assessment

CPAP FiO2 0.21

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• 1. RV pressure

RVSP – TR jet PDA shunt Septal wall motion PAAT:RVET ratio

• 2. RV Function

Subjective RV fractional area % TAPSE Tissue Doppler / Strain

• 3. Impact of PH

RV output Pulm vein S/D Vmax LV function & output

Comprehensive PH EVALUATION

HARM BENEFIT CHD NORMAL PH

McNamara and Jain 2015

Diagnostic criteria used

Baczynski et al 2017 E-PAS

Estimated sPAP vs Cath derived PAP

Mourani et al 2009

I: Tricuspid Regurgitation dependant on RV function

Bernoulli Equation [RVSP = 4 Vmax2 + Right Atrial Pressure] (i) Normal patients: TR absent or trivial (< 2 m/sec) (ii) Underestimates RVSP if RV dysfunction

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II: Septal Wall Motion impacted by LV pressure

Septum Convex Septal Flattening Septal Bowing Normal ½ to 2/3 systemic Systemic or above RV LV

(i) False negatives if Systemic Hypertension (ii) Impacted by RV vs LV systolic function

Afterload and Heart function ‐ continuum III Reliability of RV Assessment

All (n=60) Controls (n=30) PH (n=30) RV Dilation All 0.14 (0.02), p<.001 0.12 (0.04), p=.004 0.12 (0.03), p<.0001 Expert 0.15 (0.06), p=.003 0.13 (0.02), p<.001 0.17 (0.07), p=.009 Novice 0.13 (0.05), p=.003 0.22 (0.07), p=.002 0.02 (0.06), p=.38 Septal Curvature All 0.2 (0.02), p<.001 0.08 (0.03), p=.004 0.22 (0.03), p<.0001 Expert 0.23 (0.05), p<.001 0.09 (0.08), p=.13 0.23 (0.08), p=.001 Novice 0.21 (0.05), p<.001 0.06 (0.07), p=.18 0.29 (0.07), p<.0001 RV dysfunction All 0.3 (0.03), p<.001 0.11 (0.05), p=.01 0.33 (0.04), p<.0001 Expert 0.31 (0.06), p<.001 0.13 (0.01), p=.1 0.32 (0.08), p<.0001 Novice 0.35 (0.06), p<.001 0.06 (0.1), p=.3 0.4 (0.08), p<.0001

Reliability of qualitative assessment of RV dilation, septal flattening and RV systolic function

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Triaging TnECHO at 36/40

• Ex-preterm 22/40 infant
• CGA 36 week infant
• 2150 grams
• nCPAP
• 30% oxygen, SpO2 92%

Dilated RV with Septal Flattening

A: 36+2 weeks PMA PEEP 8, FiO2 35% B: 36+1 weeks PMA PEEP 9, FiO2 43% C: 37+5 weeks PMA PEEP 7, FiO2 47%

RVO = 428ml/min/kg LVO = 211ml/min/kg

B: Large left to right Atrial Septal Defect C: Pulmonary Pressure = Systemic Level

RVSp estimated at 75mmHg + Rap Systemic systolic of 81mmHg High RVET:PAAT ratio with notched PA Doppler

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Stenotic Pulmonary Veins

Peak Gradient 2.96m/s

Chronic Pulmonary Hypertension – A Spectrum

• Resistance mediated

Vasodilator

– Lung disease – Remodeling

• Flow mediated

Shunt modulation

– Chronic hsDA / ASD – AV malformations

• cPH mimicking

Disease Specific

– Pulm. Vein stenosis – Hypertension

Summary

• cPH is a physiologic spectrum disorder characterized by elevated

PAP and impaired RV performance

• TnECHO provides enhanced diagnostic precision and longitudinal

monitoring that is individualized to ambient physiology

• RV performance in health and disease requires prospective

consideration

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ASD and BPD risk

Kumar 2018 J Pediatr

Severe RV dysfunction Impaired LV Filling [Acute PH/MAP] Septal Hypertrophy

Treatment – reduce MAP as is possible, transition dopamine to vasopressin or norepinephrine Treatment – inotropic support, prostin if PDA restrictive Treatment – volume, reduce MAP, vasopressin, remove all positive inotropy

25 (86%) reported use of pulmonary vasodilators