Hi everyone,
What is your approach to dogs with cardiac murmurs and anaesthesia ? For those cases where the clinician worries about a murmur in a dog that has never presented signs of CHF , they request an echo to predict anaesthetic risks.
I usually look for :
causes of the murmur: valves
myocardial function: dilation / hypertrophy/ volume overload
pericardial disease
Then, M mode and FS to assess systolic function, Velocity of the in and outflow compared to normal, regurgitation, etc. LA/Ao ratio to assess LA enlargement and stage severity of disease.
Hi everyone,
What is your approach to dogs with cardiac murmurs and anaesthesia ? For those cases where the clinician worries about a murmur in a dog that has never presented signs of CHF , they request an echo to predict anaesthetic risks.
I usually look for :
causes of the murmur: valves
myocardial function: dilation / hypertrophy/ volume overload
pericardial disease
Then, M mode and FS to assess systolic function, Velocity of the in and outflow compared to normal, regurgitation, etc. LA/Ao ratio to assess LA enlargement and stage severity of disease.
If no evidence of severe haemodynamic consequences on these paramaters, then is anaesthetic risk low for such patient, and preinduction oxygenation , reduced or avoid ACP in premedication.
Do you use any other echocardiographic indexes of LV function, for example, to get a more clear indication of systolic/ diastolic function in a “basic” cardiac examination?
Thanks,
Silvana
Comments
fs%, lvidd, epss, la max,
fs%, lvidd, epss, la max, la/ao, mr and tr jet velocity to concern myself with systemic hypertension or pulmonary hypertension respectively, rvot and lvot velocities, as well as BP measurements. I also take a peak at the cvc and hepatic veins to ensure no dilation that would suggest passive congestion from right heart disease in the case of a very thin TR jet that I may have missed. I have had pht cases wiht normal hearts and dilated hv and cvc, rare but possible. If none of these parameters excite me then i have nop issue with anesthsia.
A side note my favorite higher risk protocol is torbutrol premed, propofol induction iso maintenance and ensure an easy induction and easy reanimation without excitement.
fs%, lvidd, epss, la max,
fs%, lvidd, epss, la max, la/ao, mr and tr jet velocity to concern myself with systemic hypertension or pulmonary hypertension respectively, rvot and lvot velocities, as well as BP measurements. I also take a peak at the cvc and hepatic veins to ensure no dilation that would suggest passive congestion from right heart disease in the case of a very thin TR jet that I may have missed. I have had pht cases wiht normal hearts and dilated hv and cvc, rare but possible. If none of these parameters excite me then i have nop issue with anesthsia.
A side note my favorite higher risk protocol is torbutrol premed, propofol induction iso maintenance and ensure an easy induction and easy reanimation without excitement.
What is important to me is to
What is important to me is to know if there´s evidence of volume or pressure overload (right or left sided) or atrial enlargement. In my opinion, the 2D-appearance (right 4-chamber, long axis) is more important than relying on measurements only. If the left free wall fits 3.5-4.5 times into the LVd, if the IVS is straight, if the interatrial septum is straight, if the LA fits into the LV 2 times at end diastole, if the right ventricle is 1/3 of the left, if the right free walll is 1/2 of the left, if the RA is smaller than the left one and to arrhythmia is detected, then there´s no increased anesthetic risk because there´s no evidence of hemodynamic compromise. In my opinion, this rule applies 99% of cases, no matter where the murmur comes from (with the exception of anorganic murmurs like anemia).
In any other case, the risk is increased. If the LA is large and the LV is volume overloaded, I look for CHF on rads. If not present, anesthesia is possible. Avoid alpha-2 agonists in these cases, assure adequate analgesia, preoxygenate and intubate them and monitor at least ECG and oxygen saturation. i.v. fluids have to be given cautiously to avoid iatrogenic congestion. monitor respiratory rate when the patient awakes.
Strictly avoid ACEI at the day of anesthesia before anesthesia (hypotension!)
In cases of severe pressure overload (stenosis, pulmonary hypertension) there´s concern of low output, tissue oxygenation and arrhythmia. Appropriate medications like Lidocaine, Esmolol, Atripine and Adrenaline shoudl be at hand. Ketamine, acepromacine and alpha 2 agonists should be avoided. Opioids, propofol, iso/sevoflurane are appropriate.
Peter
What is important to me is to
What is important to me is to know if there´s evidence of volume or pressure overload (right or left sided) or atrial enlargement. In my opinion, the 2D-appearance (right 4-chamber, long axis) is more important than relying on measurements only. If the left free wall fits 3.5-4.5 times into the LVd, if the IVS is straight, if the interatrial septum is straight, if the LA fits into the LV 2 times at end diastole, if the right ventricle is 1/3 of the left, if the right free walll is 1/2 of the left, if the RA is smaller than the left one and to arrhythmia is detected, then there´s no increased anesthetic risk because there´s no evidence of hemodynamic compromise. In my opinion, this rule applies 99% of cases, no matter where the murmur comes from (with the exception of anorganic murmurs like anemia).
In any other case, the risk is increased. If the LA is large and the LV is volume overloaded, I look for CHF on rads. If not present, anesthesia is possible. Avoid alpha-2 agonists in these cases, assure adequate analgesia, preoxygenate and intubate them and monitor at least ECG and oxygen saturation. i.v. fluids have to be given cautiously to avoid iatrogenic congestion. monitor respiratory rate when the patient awakes.
Strictly avoid ACEI at the day of anesthesia before anesthesia (hypotension!)
In cases of severe pressure overload (stenosis, pulmonary hypertension) there´s concern of low output, tissue oxygenation and arrhythmia. Appropriate medications like Lidocaine, Esmolol, Atripine and Adrenaline shoudl be at hand. Ketamine, acepromacine and alpha 2 agonists should be avoided. Opioids, propofol, iso/sevoflurane are appropriate.
Peter
Thank you Eric and Peter,
Thank you Eric and Peter, very useful tips.
Silvana
Thank you Eric and Peter,
Thank you Eric and Peter, very useful tips.
Silvana