Handling Emergencies
An emergency condition exists whenever the device is potentially or actually unable
to pump an adequate amount of blood. These conditions are signified by a HAZ-
ARD ALARM symbol and accompanied by a CONTINUOUS AUDIO TONE.
There are no backups for the HeartMate II LVAS. In the event that the LVAD stops
operating, all attempts must be made to restore pump function immediately by:
-
Checking the percutaneous lead connection to the System Controller;
-
Switching power sources, and/or
-
Replacing the System Controller (see
Replacing System Controllers
, page 35).
Loss of power will cause the LVAD to stop and blood pumping to cease. Power must
be restored immediately. If the LVAD stops, retrograde flow may occur; and, if non-
circulating blood is in the pump for more than a few minutes (depending on the
anticoagulation status of the patient), there is a risk of of stroke or thromboem-
bolism if or when the device is restarted.
If the pump’s fixed speed is set at or above 8,000 rpm, the pump should restart auto-
matically once power is restored. If the pump’s fixed speed is below 8,000 rpm, firm-
ly press the Silence Alarm or Test Select button and hold for a count of two to restart
the pump. If the pump does not restart, check all power sources and the percuta-
neous lead connection. If power source and perc lead connections are intact and the
pump still does not resume pumping after attempting restart, replace the System
Controller (see
Replacing System Controllers
, page 35). If replacing the System
Controller does not restore pump function, immediately call for additional help and
notify the patient’s physician.
Note
: Conditions that affect pump flow, such as decreased preload (LV filling),
mechanical defects, or hypertension, may limit the restoration of normal pump
flows until the condition(s) is/are resolved.
Defibrillation / Cardioversion
If
external defibrillation
is necessary, leave the pump running. Do NOT discon-
nect the System Controller from the percutaneous lead before delivering the shock.
If
open-chest defibrillation
is required, it is advised that the LVAS be disconnected
from the System Controller due to the proximity of the paddles to the device.
Note
:
Since retrograde flow may occur through the pump when it is off, it may be neces-
sary to clamp the outflow graft while the device is stopped.
CLINICAL OPERATION AND PATIENT MANAGEMENT
37
