Prevent or Treat Hemodynamic Instability
Hemodynamic instability may occur during the procedure. Therefore,
a plan must be developed to determine how instability will be
handled if it occurs.
Ischemic preconditioning is one option available to prevent
- Occlude the artery.
- Maintain the occlusion for five minutes. Monitor heart rate,
EKG, and hemodynamics.
- Reperfuse the artery for 2Š3 minutes.
|"I use ischemic preconditioning for all arteries.
The occlusion is maintained for five minutes as the EKG, hemodynamics,
and regional wall motion are monitored, followed by three minutes
of reperfusion. The artery is then occluded, opened, and the anastomosis
is made. Occasionally, intraluminal occluders are used, but most
often back-bleeding is easily controlled with a humidified CO2
- James C. Hart, M.D.
Regardless of whether ischemic preconditioning confers any protective
response, a trial occlusion can be performed to assess the initial
tolerance to ischemia. If any hemodynamic or rhythm disturbance
is noted, appropriate adjustments can be made prior to performing
the arteriotomy. Other surgeons have not found trial occlusions
or ischemic preconditioning necessary.
Although the use of a shunt has not
been proven essential for beating heart CABG, shunting is a technique
that should be in every surgeon's arsenal. The dry anastomotic
site that shunting provides, along with distal perfusion, are
The threat of heartblock
or asystole is a real concern when occluding the proximal RCA.
The RCA can be shunted to prevent potential hemodynamic instability.
In the event that instability occurs, having pacing wires available
will substantially reduce the threat of deterioration associated
with bradycardia and hypotension.
New "First Assistant" Role for the
The anesthesiologist is integral to the success of beating heart
CABG. In contrast to CABG procedures that use CPB, beating heart
CABG requires the anesthesiologist to proactively maintain stable
hemodynamics and rhythm in an environment that changes rapidly
because of regional ischemia and cardiac manipulation. The anesthesiologist's
active role during beating heart CABG requires a new level of
communication with the surgeon. The surgeon must communicate to
the anesthesiologist when the heart is being displaced, when a
coronary artery is occluded, and when a shunt has been inserted
or removed. Likewise, the anesthesiologist must keep the surgeon
informed about the use of inotropes or vasopressors, ST segment
or rhythm disturbances, and the patientÕs general condition. In
no other cardiac procedure has it been more important for the
anesthesiologist to continually observe and treat the hemodynamic
and rhythm responses to cardiac manipulation and regional ischemia.
|"Anesthesia is the critical part of the operation. When we
occlude the vessel to perform the anastomosis is when hemodynamic
instability occurs and not the moment when you go off pump. You
have to cooperate very closely with the anesthesiologist in that
- F.W. Mohr, M.D., Surgeon