Note to me: When I review any of Pediatric EM Morsels excellent posts, I follow all the links in the post which takes me deep into a review of all the associated topics. The extra time it takes me is very much worth it.
All that follows is from the above Pediatric EM Morsels’ post.
Let’s have a heart to heart. We have talked previously about pediatric myocarditis and recognizing the subtle signs of pediatric heart failure. We have even discussed some of the complications that children can get after the final stage of single ventricle palliation- a Fontan procedure. But, be still my heart! What if the myocarditis (or other causes of heart failure) are bad enough that the child needs a new heart? Well, don’t lose heart! Mechanical circulation devices are available to keep blood pumping even when the ventricles are not. Let’s talk about Pediatric Ventricular Assist Devices (VADs).
Pediatric Heart Failure
- Very different causes than in adults.
- Usually from congenital heart disease and cardiomyopathy. (Jayaprasad 2016)
- Congenital heart disease occurs in approximately 8/1000 live births, with 20% of these experiencing heart failure. (Jayaprasad 2016)
- ~10,000-14,000 children each year are hospitalized with heart failure, and ~ 3000 of those have an underlying cardiomyopathy. (Rossano et al, 2012)
- Acute rheumatic fever and rheumatic heart disease are still contributors to carditis and pediatric heart failure even in the United States. (Lahiri & Sanyahumbi 2021)
Pediatric Ventricular Assist Devices
Bridge therapy vs Destination therapy
- Bridge therapy (Seattle Children’s 2021)
- Bridge to Transplant
- Supports the circulation until they can receive a heart transplant.
- This is most common.
- Bridge to Recovery
- Much less common.
- Supports heart muscle after myocarditis or another temporary diagnosis until the heart regains its function.
- Destination therapy (Rose 2001, Seattle Children’s 2021)
- The VAD device is meant to support circulation indefinitely.
- Usually when patients are not candidates for heart transplants, the VAD devices can still improve quality of life.
Left vs Right vs BiVentricular
- Depending on the ventricle(s) that are failing, different devices can be used.
- The Berlin Heart (EXCOR® Pediatric) is the only pediatric device currently that can provide right ventricular and biventricular support.
- There are many sizes that can be used for any age.
- There are multiple devices that can provide left ventricular support
- Many have size (BSA > 1.2-1.5 m2) limitations. (Abbott 2021, Abbott 2021)
Pediatric Ventricular Assist Devices: Flow
Pulsatile Flow vs Continuous Flow (Eisen 2019)
- Pulsatile flow
- Pneumatrically driven membrane in the Berlin Heart (EXCOR® Pediatric).
- The membrane is visible outside the body.
- Patients with a Berlin Heart (EXCOR® Pediatric) typically remain admitted to the hospital until they undergo heart transplantation.
- Continuous flow devices
- What you will most likely see in the ED.
- The device is internal except for the driveline
- Patients won’t have a pulse
- Use a doppler to assess minute pulsatile flow
- Monitor mean arterial pressures.
- Most common are the HeartWare, HeartMate II™ (Abbott), CentriMag™ (Abbott) and HeartMate 3™ (Abbott). (Seattle Children’s)
Pediatric VAD Assessment: (LVAD)2
(LVAD)2 is a useful mnemonic for LVAD Assessment (Noste, Lupez, 2019)
Look / Listen (and feel)
- Look: Green light (or yellow or red), full battery signal? Adequate RPMs? error messages?
- Listen (and feel): You should hear a constant hum of the device.
- A quiet LVAD is BAD NEWS.
- Listen for any alarms to signal badness, too!
- Feel the LVAD to see if it is very hot, which can signal obstruction, thrombosis, or dislodgement.
Ventricles / Venous Thromboembolism (Eisen 2019)
- Use POCUS to look at any extreme dilation of the ventricles
- Could indicate pump thrombus, right sided myocardial infarction, or pulmonary embolism.
- Venous Thromboembolism:
- Patients are at risk of TIA, stroke, PE, DVTs, or pump thrombi.
- Pump thrombus = elevated RPMs + elevated pump power + overheated device + low flow of device.
Anticoagulation / Arrhythmias
- Patients on aspirin and warfarin, or sometimes clopidogrel
- INR goal 2-3
- If INR drops < 1.5 they are at risk of thrombus or embolic events
- Elevated INR increases risk for bleeding – epistaxis, intestinal bleeding, spontaneous AV fistula rupture, head bleeds, acquired von Willebrand disease
- May alter flow of blood through the device, and must be treated!
- VFib and VTach should be treated – it is safe and recommended to defibrillate patients when clinically indicated!
- Check an EKG and compare to previous
Driveline/Dehydration (Shinar ED ECMO)
- Driveline: Big risk of infection (40-60% will develop)
- Dehydration: May lead to suction events and arrythmias. LVADs love fluids.
Pediatric VAD & CPR?
- You can do chest compressions safely! (Peberdy 2017)
- There have been no case reports of device dislodgement from CPR.
- You can defibrillate or cardiovert safely!
- You can use all PALS and/or ACLS drugs safely!
- If in cardiac arrest, treat them as you would anyone else.
Pediatric Cardiologist Pointers
- Call Pediatric Cardiology (and maybe even the cardiothoracic surgeon) when the patient arrives!.
- LVADs will tell you what is wrong, just look at the error messages.
- Never reverse anticoagulation. EVER. Even with bleeding.
- Use Nicardipine to lower elevated BPs. Hypertension can cause pump malfunctions.
- Vancomycin and Cefepime for any concern of infection.
Moral of the Morsel
- Pediatric patients can have heart failure and need for mechanical circulatory support.
- Pediatric patients may come in to your ED with an LVAD! Be vigilant about how to assess their LVAD and who to call for help with troubleshooting.
- You can perform normal CPR for these patients.
- GET PUMPED to care for these patients!