The Collapsed Infant (Child) with Suspected Heart Disease (A Pragmatist’s Guide) Nick Pigott Staff Specialist in Paediatric Intensive Care Children’s Hospital at Westmead PAC 2012, November 16 th and 17 th

Resus room perspective… The collapsed newborn… –The case for considering heart disease –Diagnostic approach –Clinical management –(HLHS) Other customers: –Cardiomyopathy/myocarditis –(arrhythmias) –‘known’ cardiac patients

Congenital Heart Disease (CHD) accounts for 20% of all congenital malformations

Modes of detection of CHD Fetal USS Post natal examination Six week check Parental concern/acute presentation

1590 with CHD (~300,000 live births) 523 presented before neonatal exam Routine neonatal examination failed to detect more than half babies with heart disease Routine exam at 6/52 missed 1/3

‘Normal’ circulation  effectively 2 pumps in series Systemic blood flow (Qs) = Pulmonary blood flow (Qp) Qp Qs

3 main ways babies present with congenital heart disease… 1.SHOCK (obstructed flow to body) 2.“BLUE” (obstructed or restricted flow to lungs) 3.HEART FAILURE (excess volume load, eg. large AV canal defect) [at least the ones intensivists worry about…]

Fetal circulation and the duct

In some newborns with CHD… Emulating a ‘balanced’ circulation may be dependent on maintaining flow across a persistent arterial duct Ductal patency can be sustained using an infusion of Prostaglandin E [5 – 100ng/kg/min]

‘Varieties’ of duct-dependent circulation Duct-dependent mixing Duct-dependent pulmonary circulation Duct-dependent systemic circulation

‘Mixing’ lesions Transposition of the Great Arteries (with or without VSD ) Systemic oxygenation dependent on mixing at atrial, ductal levels (+VSD) Presentation:Cyanosis Management: PGE infusion May require ventilation for transfer Definitive balloon atrial septostomy (BAS) Occasionally babies will have intractable hypoxaemia and metabolic acidosis despite ductal patency – urgent transfer for BAS

Duct-dependent pulmonary circulation (obstructed pulmonary circulation) Pulmonary atresia with intact ventricular septum Critical pulmonary stenosis Tricuspid atresia Presentation:Cyanosis (murmur) Management: PGE infusion Often results in significant improvement Aim for percutaneous sats of 70 – 85% Adequate urine output, absence of metabolic acidosis May require ventilation for airway control/systemic collapse

Duct-dependent pulmonary circulation Management (continued): If confident underlying cause is cardiac  aim for ‘normo’- ventilation and keep FiO 2 between 0.21 and 0.4 HOWEVER! May be indistinguishable from Persistent Pulmonary Hypertension of the Newborn (PPHN)! …in which case, will need mechanical ventilation optimised to reduce PVR Aim for: PaO 2 > 80mm Hg (~100% FiO 2 ) pH 7.40 – 7.45 iNO, MgS0 4,, bicarbonate muscle relaxation, sedation

Duct-dependent systemic circulation (critically obstructed systemic circulation) Coarctation of the aorta Interruption of the aortic arch Hypoplastic left heart syndrome (HLHS) Presentation: Collapse, metabolic acidosis, oliguria, absent femoral pulses NB. Systemic, myocardial (coronary) and pulmonary circulations are all in parallel

Duct-dependent systemic circulation (critically obstructed systemic circulation) Management: PGE infusion to re-open duct AIM is to ‘Balance’ pulmonary, systemic (and coronary) circulations by manipulating PVR and SVR If collapsed  intubation and ventilation Fluid resuscitation Inotropes/inodilators (dopamine, adrenaline, milrinone)

Mini summary… CHD commonest congenital anomaly Should be considered as underlying cause in presentation of collapsed newborn Effective clinical mx does not require knowledge of specific underlying lesion

Clinical approach Physical examination –Cyanosis –Murmur –Pulses –Signs of heart failure (resp rate, hepatomegaly)

Clinical approach… CXR Heart size Pul vascularity (too much/too little) ECG

Initial management of the newborn in shock with suspected CHD Airway Management IV Access PGE 1 Antibiotics Volume, Calcium, Glucose Supplemental O 2 if needed Crossmatch

Call for Help!

Case Born at 42 weeks gestation. Normal delivery and Apgar score. Poor feeding and breathlessness noted at 2 days. Readmitted to hospital. Hepatomegaly, weak peripheral pulses and acidosis. Retrieval requested.

Team arrival… Gasping, grey and grunting Impalpable peripheral pulses Single heart sound CXR: Cardiomegaly Blood gases: Base deficit of -22, pH = 7.01 Blood glucose: 1mmol/L Echo: HLHS, tiny arterial duct

Resuscitation on site Intubated and ventilated Paralysed and sedated Central venous and arterial catheters Prostaglandin infusion increased Ventilated FiO 2 = 0.21 (O2 sat = 80%) pCO 2 = 6 Transferred

I II III aVR aVL aVF ECG

Parallel circulations Reduced systemic perfusion = Excessive pulmonary blood flow (PBF) until proven otherwise Poor Ventricular function = Poor myocardial blood flow = Excessive PBF Usually, high-dose Inotropes not required

HLHS RA LA RV LV

HLHS

Other ‘cardiac’ customers… Cardiomyopathy/myocarditis (Arrhythmias) The “known” cardiac patient

Dilated cardiomyopathy (DCM) 36.5/ Most commonly within first 2y Heart usually huge, big liver Ejection Fraction~10-20%!

Other ‘cardiac’ customers… Cardiomyopathy/myocarditis (Arrhythmias) The “known” cardiac patient

Other ‘cardiac’ customers… Cardiomyopathy/myocarditis (Arrhythmias) The “known” cardiac patient

Summary Newborns present collapsed as a consequence of congenital heart disease surprisingly often Consideration of the likely underlying physiology (rather than the exact lesion) may usefully guide clinical management Some features are more useful than others…

The Money… Murmur Cyanosis Diminished peripheral pulses Physical signs of heart failure Prostaglandin infusion CXR (ECG) ?Oxygen might not be the best thing…

Thank you!