Situation
How do you manage the
following situations in patients presenting for a thoracotomy and lung resection
?
1 Coronary disease
2 Valve disease
3 Combined coronary
and valvular disease
1 Coronary disease
Symptoms guide
management here. With lots of angina a cardiological assessment is needed re
exercise test or go straight to Angiography. The role of medical management,
angioplasty +/- stenting and surgery obviously needs to be assessed for each
case individually. Echocardiography can be quite helpful to asses LV and RV
function and PA pressure. Remember that it is RV function that is also
important, as you will be potentially doubling the pulmonary vascular resistance
when doing a pneumonectomy.
2 Valve disease
Echocardiography is
the initial test in all cases, followed by left and right heart catheterisation
+/- coronary Angiography in selected cases. In general:
1 Aortic stenosis –
patients with a high gradient (mean >40 to 50mmHg) may need valve replacement
pre thoracotomy. Beware of epidurals lowering the SVR, dropping the diastolic
blood pressure, and hence compromising coronary flow. Mild AS (grad <30mmHg)
is usually well tolerated.
2 Aortic
regurgitation – well tolerated even if quite severe, unless LV function is
severely compromised or pulmonary artery pressure is raised. Anesthesia and
epidurals help reduce the regurgitatant volume via the reduction in SVR.
3 Mitral
stenosis– patients with a small valve area (<1.5cm2) may need valve
replacement pre thoracotomy. Assessing PA pressure is an important factor in
deciding what to do. Mild MS is well tolerated (valve area >1.5cm2).
4 Mitral
regurgitation - well tolerated even if quite severe, unless LV function is
severely compromised or pulmonary artery pressure is raised. Anesthesia and
epidurals help reduce the regurgitatant volume via the reduction in SVR.
Assessing PA pressure is an important factor in deciding what to do
3 Combined coronary
and valvular disease
Same as above but a
lower threshold for cardiac surgery / cardiological intervention is needed.
4 Pacemaker
If defibrillating
turn defib function off. Changing to fixed rate, will help in reducing diathermy
interference. Always change back to original setting immediately post op, apart
from defibrillating function which should probably only be turned on when back
on the ward and mobile. Occasionally the intrinsic rate needs to be turned up
for a few days and then lowered back to the base line to help in the
physiological adaptation to the surgical and anaesthetic insult.