Advantages of OPCAB Over MIDCAB
- Intubation: No
need to selectively intubate one lung and avoids the potential hypoxemia
caused by collapsing a lung.
- Cardiopulmonary Resuscitation
(CPR): If CPR is needed, open chest CPR is much more effective
than closed chest compressions.
- Cannulation: Standard
cannulation sites are readily accessible.
Standard size paddles fit through a sternotomy incision while that
may not be the case for a MIDCAB incision.
- Graftable Areas:
Access to all coronaries.
Considerations for Beating Heart Surgery
There are several very important
considerations when approaching a beating heart CAB case:
- 1. Patient History.
- The anesthesiologist
should be very familiar with the coronary anatomy in general, and
with the patient's specific lesions in particular. It is not enough
to know that the patient has 3-vessel disease; you must also be aware
of the severity of the lesions and their specific locations. One should
also know the ejection fraction (EF), and if there is a global cardiomyopathy,
history of valvular disease or recent myocardial infarction (MI).
- 2. Communication between
the Surgeon and the Anesthesiologist.
- 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
with 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 patient's 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.
- Standard ASA
- Arterial Catheter
- Central Venous A
- Ischemia Monitoring
- EKG ST trend
- PA Catheter?
|EKG - electrocardiogram; PA Catheter - pulmonary artery catheter;
TEE - transesophageal echocardiography
Standard ASA monitors and
arterial lines are needed during the beating heart surgery. Central
vascular access is also necessary for administration of vasoactive drugs
and monitoring. The Emory team recommends using an introducer through
which you can rapidly feed a pulmonary artery catheter if required.
For ischemic monitoring,
the electrocardiogram (EKG) is critical but also has important limitations.
There is debate over whether to use a pulmonary artery (PA) catheter,
transesophageal echocardiography (TEE), both, or other modalities in
these cases, and this issue will be discussed later in this document.
The anesthetic management
presents a particular challenge because it requires the anesthesiologist
to balance two opposing problems. Ideally the anesthetic technique is
geared towards allowing early extubation of the patient by giving short-acting
drugs, and avoiding high-dose opiates that would prolong emergence.
At the same time, the operation can be characterized by periods of hemodynamic
instability which are easier to manage if the anesthetic is based on
high doses of opioids. In addition, it can be difficult to estimate
the depth of anesthesia at times when low doses of inhaled anesthetic
are being given because the hemodynamic parameters are markedly affected
by the surgical manipulation. In this situation we have found that the
information given by the Bi-spectral index is a useful guide to help
ensure that appropriate amnesia is provided to the patient. In addition,
we use continuous infusion of an opioid such as fentanyl to provide
analgesia. This option is well tolerated, even by patients who are hemodynamically