Definition:
Paracorporal, pneumatically driven, pulsatile flow mechanical support device driven by a central driving unit (Ikus®) and different sizes of blood pumps (10, 25, 30, 50, 60, 80ml), can be used as RVAD, LVAD or BIVAD.
Aim:
Bridge to transplant or bridge to recovery
Standard settings:
| Driving pressures for Systole and Diastole (Chamber Size / LVAD / RVAD) |
||
| 10 ml | 225 / 175 | – 50 / – 50 |
| 25 ml | 175 / 150 | – 50 / – 50 |
| 30 ml | 175 / 150 | – 50 / – 50 |
| 50 ml | 175 / 150 | – 25 / – 25 |
| 60 ml | 200 / 150 | – 25 / – 25 |
| 80 ml | 225 / 175 | – 25 / – 25 |
Anticoagulation guide:
| Medications / Dosing / Target | ||
|
start UFH+ >24 hr post OP+ no bleeding + platelets >20.000 + normal TEG |
start witha) <12 month: 15 U/kg/hr (no bolus) and increase after 6hrs to 28 U/kg/hrb) >12 month: 10 U/kg/hr (no bolus) and increase after 6 hrs to 20 U/kg/hr |
aPTT 1.5-2.5 of normal (check every 6 hrs)or Anti-Xa 0.35-0.50 U/ml (draw level 4 hrs after 2nd dose) |
|
start LMWH+ creatinine normal+ no bleeding or if + unable to tolerate PO + unstable INRs + convert after UFH and no bleeding |
start with Enoxaparina) <3 month: 1.5 mg/kg BDb) >3 month: 1 mg/kg BD or if low INR 2.0-2.7: 1 mg/kg/ OD or if low INR <2.0: 1 mg/kg BD |
Anti-Xa 0.6-1.0 U/ml (draw level 4th after 2nddose until stable) |
| start Vitamin K Antagonist (bridge with LMWH)+ if age >12 month+ enteral feeds tolerated |
Warfarin 0.2 mg/kg/day(maximum 5 mg/day) | INR 2.7-3.5(use LMWH if unstable INRs) |
|
start Platelet inhibitorsDipyramidole+ if Platelets >40.000 + postop Day 2 and ADP >50% + Aspirin + if platelets >40.0000 + postop Day 4 and drains removed and ARA >50% |
Dipyramidole 1 mg/kg/dose QID (maximum 15 mg/kg/day)Aspirin 1 mg/kg/day | ADP activity <50%ARA activity <30% |
Trouble shooting: always inform PICU consultant for any changes !
| Insufficient filling of VAD (VAD Diastole) | |
| Hypovolaemia | check Hb and drain losses → replace volume |
| changes in intrathoracic pressure | check CXR (pneumothorax?), ventilation settings → aim for early extubation to increase CO (negative impact of positive intrathroacic pressure) |
| Tamponade | ECHO warranted, inform surgeon ASAP |
| increased PVR | lower PVR (pulmonary hypertension), check right heart function on ECHO |
| Kink in inflow cannula | check for mechanical obstruction: extracorporal / intracorporal (ECHO) |
| right heart failure(LVAD only) | check right heart function with ECHO → inotropic support of right heart (dobutamine, milrinone), →→ NO , RVAD |
| too low negative vacuum pressure | increase negative vacuum pressure (be careful not to suck air in) → driving pressures |
| VAD rate too high | lower VAD rate, decrease % systole |
| Insufficient emptying of VAD (VAD Systole) | |
| increased PVR (in RVAD) | lower PVR (pulmonary hypertension) |
| increased SVR (in LVAD) | lower SVR (vasodilators) |
| Kink in outflow cannula | check for mechanical obstruction |
| systolic drive pressure too low | increase systolic driving pressure (→ driving pressures) |
References:
[1] J of Cardiovasc Trans Res (2010) 3:612-617: Bryant 3rd: Current Use of the EXCOR Pediatric Ventricular Assist Device
[2] Artif Organs. 2010 Dec;34(12):1082-6: Humpl et al: The Berlin Heart EXCOR Pediatrics-The SickKids Experience 2004-2008
[3] Ann Thorac Surg. 2005 Jan;79(1):53-60; discussion 61: Groetzner et al: Cardiac transplantation in pediatric patients: fifteen-year experience of a single center
[4] J Heart Lung Transplant. 2009 Apr;28(4):399-401. Irving et al: Successful bridge to transplant with the Berlin Heart after cavopulmonary shunt
[5] Am Heart J. 2011 Sep;162(3):425-35.Almond et al: Berlin Heart EXCOR Pediatric ventricular assist device Investigational Device Exemption study: study design and rationale
[6] J Thorac Cardiovasc Surg. 2011 Mar;141(3):616-23, 623: Hetzer et al: Single center experience with treatment of cardiogenic shock in children by pediatric ventricular assist devices
[7] Artif Organs 2012 Jul;36(7):635-9: Sharma et al: Ventricular assist device support in children and adolescents with heart failure: the Children’s Medical Center of Dallas experience
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