double outlet right ventricle -subaortic vsd...

Double Outlet Right Ventricle-Subaortic VSD Christine M. Riley, BS, MSN, APRN, CPNP-AC

Disclosures

I have no financial disclosures.

(Accepting offers or donations, grad school was expensive…)

Objectives

• Describe specific anatomy of DORV/Subaortic VSD

• Review preoperative physiology of DORV/Subaortic VSD

• Explain currently utilized surgical options for children with DORV/Subaortic VSD

• Summarize important post-operative considerations for children with DORV/Subaortic VSD

Introduction

• Most common variation of DORV ~55-70%

• VSD is closer to Ao valve than to PV and is to the right of the conus septum

• Right ventricular outflow track obstruction is common ~50%

Embryology: “We all start as DORV…It’s all about the conus”

Embryology

Objectives





Clinical Framework

Optimize for Operating

Room Hemostasis Hemodynamic

Stability Diuresis & Extubation Thrive & Grow IF NOT, WHY NOT?

Optimize for OR: Preoperative Anatomy

• Confirm relationship of great vessels/conal septum and VSD

• Evaluate degree of RVOTO • RVOT obstruction most commonly due to infundibular

stenosis/deviation of the conal septum, but more rarely may be valvar or even pulmonary atresia

• Evaluate for other cardiac abnormalities – CAVC – Coronary anatomy

Optimize for OR: Preoperative Physiology

• Degree of RVOT obstruction determines preoperative physiology

• VSD verse TOF VSD TOF


• VSD-like physiology – VSD is typically unrestrictive – Pulmonary blood flow

determined by relationship of PVR and SVR

– Volume loads LV – As PVR falls Qp:Qs > 1

creating s/s of CHF – PVR increases in response to

the volume and pressure load, if left unaddressed increased PVR may become fixed resulting in pulmonary hypertension


• TOF-like physiology – Pulmonary blood flow is

determined by the degree of RVOT obstruction

– Pressure loads RV – May create a balanced

circulation but more commonly Qp:Qs <1 resulting in cyanosis

– Obstruction may have dynamic component creating hypercyanotic episodes


VSD-like (no PS) TOF-like (PS)

Optmize growth (ñkcal/kg/day)

✔ ✔

Diuretics ✔ Unlikely

Digoxin ✔ Unlikely

Oxygen ✔

Optimize for OR: Associated Conditions

• Abdominal Ultrasound – Eval for heterotaxy

• Situs of abdominal organs

• Asplenia/polysplenia • Venous anatomy

• Preoperative brain MRI • Genetic testing

Objectives





Surgical Options

• Typically amenable to complete primary biventricular repair

• Depends on preoperative physiology i.e. amount of RVOT obstruction

• May require initial palliation (BTS vs. PAB)

Surgical Repair

VSD Physiology

• Typically repaired in first 3-4 months (before fixed ñ PVR)

• VSD patch closure baffling LV blood to Ao

• May require enlargement of the VSD if septal defect is smaller than Ao orifice

TOF Physiology

• RV outflow track augmentation in addition to baffle closure of VSD

• Extent depends on degree of obstruction – Infundibular patch – Transannular patch – RV to PA conduit (Rastelli)

Objectives





Hemodynamic Stability: Post Operative Anatomy

• Depends of degree of RVOT obstruction (if any) and how it was relieved – Non-transannular patch – Transannular patch – RV to PA conduit

• Was a right ventriculotomy required?

• Is there an remaining atrial level communication?

Hemodynamic Stability: Post Operative Physiology

• What do we worry about post op? – Oxygen balance – RV failure – LV failure – Hypoxia: Resp vs. CV – Residual Lesions – Arrhythmias (JET)

Hemodynamic Stability: Post Operative Management

Physiology Review…

• Q = ΔP/R

• CO = HR x SV

• DO2 = CO x CaO2

Oxygen Delivery

Amount of O2 in the

blood

Cardiac Output

Oxygen Delivery

Remember…

Preload

Contractility

Afterload

Heart Rate Cardiac Output

Oxygen Delivery

Optimizing Oxygen Balance

• O2 Consumption = O2 Demand • Always a priority • Avoid: tachycardia, fever, needless procedures/cares,

too much touching, acidosis, hypoxia, electrolyte imbalances, anemia

• Promote: clustered cares & periods of rest, enhanced awareness during routine cares, careful lab monitoring, situational awareness/critical thinking

Optimizing Oxygen Balance

Conditions & Associated Approximate Increase in O2 Consumption

Fever (per °C) 10% Work of breathing

40%

Shivering 50-100% Postop procedure 7%

ETT Suctioning 7-70% MODS 20-80%

Sepsis 50-100% Dressing Change 10%

Visitor 22% Bath 23%

Position Change 31% Chest Xray 25%

Weighing patient 36%

Clinical Framework

Optimize for Operating

Room Hemostasis Hemodynamic

Stability Diuresis & Extubation Thrive & Grow IF NOT, WHY NOT?

Is your kid being a BRAT? • B: Bleeding? - > 3mL/kg/hr for 2-3hrs or

>5-10mL/kg for 1 hr

• R: Residual Lesions? - post op TEE look like?

• A: Arrhythmia? - check all your monitored

waveforms esp. RA/LA

• T: Tamponade? - tachycardia, narrow pulse

pressure, increased CVP/RA/LA, check window

RV failure/Restrictive RV Physiology

• Causes: – Right ventriculotomy plus CPB

and immature myocytes lead to diastolic dysfunction creating restrictive RV physiology

– RV must receive increased volume to force it to distend & recoil to maintain CO

– Pulmonary hypertension (this subset of DORV at highest risk)

– Residual RVOT obstruction

• Characterized by s/s of systemic venous congestion – Increased CVP/RAP – Hepatomegaly – Peripheral edema – Signs of LCOS if left

unaddressed

Hemodynamic Stability: Managing RV Failure

• Appropriately volume load, AVOID over distension

• Afterload reduce with milrinone, oxygen, and iNO if needed

• Situational awareness around cares that increases O2 demand

• Evaluated long term outcomes on RV function for limited right ventriculotomy (<1cm) vs. standard in TOF repair • No benefits in terms of RV volume or function as measured by post op cardiac MRI • RV function abnormalities found in both groups

Hemodynamic Stability: LV Failure

• Causes: – Acute increase in LV

afterload following VSD closure

– Obstruction to systemic output

– Aortic insufficiency – Myocardial ischemia – LCOS

• Characterized by s/s of low CO – Cool extremities – Lactic acidosis – Pulmonary edema – High LAP

Hemodynamic Stability: Hypoxia

Decreased RV Function • Decreased RV function creates

elevated RVEDP and RàL shunt at PFO

• Increased RàL creates decreased saturation

• Know your PFO (blue vs. grey) • Is expected to some extent, but

be careful that you don’t lower your standards too much!

• S/S of restrictive physiology • Treat according

PV Desaturation

• Pulmonary edema secondary to reperfusion injury

• Atelectasis • DOPE Displacement, Obstruction, PE/Pneumothorax Equipment

Hemodynamic Stability: Residual Lesions

• RVOT obstruction -increased pressures will

cause increased RàL shunt creating hypoxia

• Residual VSD -poorly tolerated -volume loads LV -compromises systemic

output • Systemic obstruction by

baffle patch or restrictive VSD

Hemodynamic Stability: JET

Cannon A-Waves

Hemodynamic Stability: JET Management

• Rate control vs. rhythm control

• Decrease O2 demand & rate control:

cool/tylenol , sedate, paralyze, wean inotropes

• Rhythm control: Amiodarone, Procainamide, overdrive pacing

Hemodynamic Stability: JET Management

Kadam et al. (2015) Effect of dexmeditomidine on postoperative junctional ectopic tachycardia after complete surgical repair of tetralogy of Fallot: A prospective randomized controlled study. Annals of Cardiac Anesthesia, vol 18:3, 323-328.

Thrive & Grow: Long-term Care and Outcomes

• Excellent long-term outlook in general – CICU morbidity

• ~20% will need reoperation of the interventricular baffle

• RV to PA conduit/pulmonary valve replacements • Long term follow-up for RV size and function

Things to take away…

• Please don’t underestimate the power your knowledge has at the bedside, everything we do matters

• Understanding what we do

and why makes us better advocates, better clinicians, and elevates our practice and profession as a whole

• Nursing needs you, find a way to get invested and stay invested

References Jonas, R. (2014) Comprehensive Surgical Management of Congenital Heart Disease, 2ed Ed. Boca Raton,

FL: CRC Press. Kadam et al. (2015) Effect of dexmeditomidine on postoperative junctional ectopic tachycardia after

complete surgical repair of tetralogy of Fallot: A prospective randomized controlled study. Annals of Cardiac Anesthesia, vol 18:3, 323-328.

Lee et al. (2014) Does limited right ventriculotomy prevent right ventricular dilatation and dysfunction in patients who undergo transannular repair of tetralogy of Fallot? J of Thoracic and Cardiovascular Surgery, 147: 3, 889-896.

Masse, L., & Antonacci, M. (2005). Low cardiac output syndrome: Identification and management. Critical Care Nursing Clinics of North America, 17(4), 375-383.

Nichols et al. (2006) Critical Heart Disease in Infant and Children, 2ed Ed.. Philadelphia, PA: Mosby Elsevier.

Park, M.K. 2008 (5th Edition) Pediatric Cardiology for Practitioners. St. Louis: Mosby Year Book. Wessel, D. L. (2001). Managing low cardiac output syndrome after congenital heart surgery. Critical

Care Medicine, 29 (10 Suppl), S220-30.

double outlet right ventricle -subaortic vsd...

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