Restrictive right heart SOP

This is an agreed pathway for the peri-operative management of patients undergoing primary repair of Fallot’s and DORV continuum.  It may well be considered applicable to patients with analogous physiological substrate.  It is not intended as a binding or detailed clinical guideline but rather represents an agreed consistent strategy. Similarly, it does not seek to cover every aspect of care, particularly where other guidelines apply.  

This is a demanding and highly variable group of patients who have a significant mortality and morbidity risk and frequently have long PICU stays.

In 2000, 9.1% of the 261 operations to repair ToF in the UK, resulted in death within 1 year (ie 24 deaths in one year). In 2015 the 30 Day mortality for ToF was zero. The 1 year mortality data from 2015 is not yet available. The post-operative survival data in the UK and Ireland for ToF remains daunting.  NICCOR data over its entire 16 year data set (4382 operations) shows a 30 Day Mortality is 1.3% and (3843 operations) 1 year mortality of 3.0%.  For the most recent 5 years of data the 30 day mortality is 0.4% (2011-15inc, 1514 operations) and 1 year mortality is 1.9% (2009-13 inc, 1545 operations). Post-discharge mortality in this group is rare.

This means effectively that we would reasonably expect 49 in 50 patients in this group to survive surgical repair and the post-operative course.  This risk burden can reasonably be assumed to be much higher in those patients with less favourable ToF anatomy and physiology but individual characterisation of risk in this group remains difficult and inexact.

RV dysfunction is insidious. The results of ECLS in this group are poor. 

It is, of course, inevitable that deviation from the pathway will be necessary but that this will be done after cross-speciality discussion and clinical review of the patient.

• Pre-operative phase:
  • Identify patient as having potential Restrictive RV pre-operatively and highlight at JCC (ToF and DORV surgery and patients with RVOTO or similar).
  • Review and agree at pathway at morning theatre brief and PICU cardiac round so all team on same page. The aim is to prevent descent into worsening RV Dysfunction/ Low Co/ Restriction in the hours following surgery (the “Evening dip”) by planned steady management.
• Intra-operative and post-operative phase:
  • Cardiac:
    • Permissive moderate systemic hypotension can be accepted as long as markers of cardiac output are adequate – avO2 / NIRS / lactate trends.
    • Accept that a higher RVEDP may be necessary and necessitate filling – target specific CVP range
    • Avoid direct adrenergic agents if possible.
    • Milrinone 0.5 mcg/kg/min. Start on bypass.  No loading bolus.
    • Noradrenaline 0.05 mcg/kg/min. Start on bypass.  Titrate to off-bypass systemic pressure.
    • If vasoplegic despite Noradrenaline up to 0.1 mcg/kg/min, consider Vasopressin infusion.
    • In anticipated severe Restrictive RV (eg small PAs/Tight Annulus/ High Collateral Flow on Bypass) start inhaled Nitric in theatre. Avoid cessation of Nitric during transfer.  Wean Nitric slowly aiming to avoid rebound pulmonary hypertension.
  • Respiratory:
    • Bilateral pleural drains to be sited in theatre and left in place till at least day 3 post-op. Mediastinal drains to be sited as standard.
    • Aim for low ventilatory pressures and modst PEEP (eg 4-6), using pressure control/pressure support ventilation mode setting tight etCO2 targets (eg 4.0-5.0KPa).
  • Predicted flightpath:
    • If a patient is on this pathway they are, by definition, NOT on a rapid recovery pathway. Aim for overnight ventilation and extubation on Day 1 at earliest.
    • RV dysfunction is insidious. Avoid independent escalation of therapy as much as possible.  Involve the rest of the team early with an echo to guide further intervention should therapy be escalating or the need for extra inotropic agents.