Cardiovascular Critical Care I
Short to Intermediate Term
Extracorporeal life
support (ECLS)
or extracorporeal
membrane
oxygenation (ECMO)
| • | Similar to cardiopulmonary bypass in which large-bore cannulas drain venous blood |
|---|
that is pumped through an oxygenator, where it is oxygenated and/or cleared of carbon
dioxide and then actively pumped back into the body
| • | Modality of support depends on the means of vascular cannulation |
|---|
Venoarterial: Removal of venous blood from the vena cava with circulation through the
ECMO circuit and delivery in retrograde fashion up the aorta; potentially indicated
for primary cardiogenic shock, cardiopulmonary failure, and post-cardiopulmonary
circulatory shock
Venovenous: Removal of venous blood from the vena cava with circulation through
the ECMO circuit and delivery back to the right atrium; potentially indicated for
hypoxic respiratory failure owing to any cause, hypercarbic respiratory failure with
bronchospastic disease or other cause of carbon dioxide (CO2) retention, or severe air
leak syndromes
Long term
Implantable LVADs
Examples include the HeartMate II (no longer commercially available), HVAD (no longer
commercially available), and HeartMate 3
Total artificial heart
Example includes Syncardia TAH (biventricular support)
LVAD = left ventricular assist device; VAD = ventricular assist device.
| d. | Anticoagulation considerations |
|---|
Anticoagulation strategies are specific to the proprietary device, and many institutions have
standardized protocols.
ii.
Safety and efficacy of DOACs in patients with ventricular assist devices (VADs) have not been
well established.
Complications of MCS (other than device failure)
Bleeding
Common sources
| (a) | Nasal/upper airway |
|---|---|
| (b) | Gastrointestinal (GI) |
| (c) | Arteriovenous malformations in one of the previously stated locations |
| (d) | Hemolysis |
ii.
Workup and/or acute treatment options
| (a) | Laboratory workup |
|---|---|
| (1) | Prothrombin time/INR/aPTT |
| (2) | Increase frequency of hemoglobin/hematocrit evaluation. |
| (3) | Multimeric von Willebrand testing for acquired von Willebrand factor deficiency |
(some clinicians believe that all patients with prolonged continuous flow MCS develop
acquired von Willebrand disease)
| (4) | If no overt sign of bleeding – Consider hemolysis workup. |
|---|---|
| (b) | If suspected/confirmed bleeding, hold anticoagulation and consider reversal with |
caution. Consider any history of bleeding/clotting-related problems and indications for
antithrombotic therapy in addition to MCS.
| (c) | Obtain appropriate consults, and consider common interventions. |
|---|---|
| (d) | Ear, nose, and throat: |
| (1) | Evaluate for source control and/or cauterization. |