There’s been a big debate re: who should care for LVAD patients… a general anesthesiologist or a cardiac anesthesiologist? See below for pros and cons of each. Ultimately, I think all anesthesiologists should be comfortable caring for these patients as we’ll see more and more LVAD patients undergoing procedures.
Goals of care for LVAD patients undergoing non-cardiac surgery should be directed at maintaining forward flow and adequate perfusion. Three main factors that affect LVAD flow are preload, RV function, and afterload.
The right ventricle is the primary means of LVAD filling; therefore, maintaining RV function is imperative.
Marked increases in systemic vascular resistance should be avoided.
Generally, decreases in pump flow should first be treated with a fluid challenge. Hypovolemia should be avoided and intraoperative losses should be replaced aggressively. Second line treatment should include inotropic support for the right ventricle.
Low-dose vasopressin (<2.4 U/h) may be the vasopressor of choice due to its minimal effect on pulmonary vascular resistance.
Standard Advanced Cardiovascular Life Support Guidelines should be followed; however, external chest compressions should be avoided during cardiac arrest.
Steep Trendelenburg may increase venous return, risking RV strain. Peritoneal insufflation for laparoscopic surgery also increases afterload and has detrimental effects on preload. Insufflation should utilize minimum pressures and be increased in a gradual, step-wise fashion.
TEE can be extremely valuable in diagnosing the cause of obstruction.
Transthoracic echo: a beginner’s guide #tte #cardiac #echo #meded
Knowing how to do a quick focused echo exam can be instrumental in diagnosis as well as treatment. This has helped me determine how severe cardiac tamponade has been in an emergent case prior to induction when there was no prior echo. There are so many more useful answers that a bedside echo can provide. Time to get acquainted.
Today, we had a guest speaker Christian Spies from Queen’s Hospital in Hawaii who spoke on his experience with his TAVR team and conscious sedation vs. general anesthesia for these patients. More specifically, we are speaking of the transfemoral route.
Patient selection is key (consider for COPD; bad for OSA)
Short surgical time for monitored anesthesia care (MAC)
Decrease invasive monitoring (no PA catheter,+/-CVP)
No difference in hospital LOS or 1 year mortality rate
Move from TEE to TTE if MAC
Be prepared to convert MAC to GA (can be difficult in already tenuous patient in a crowded space under the drapes)
MAC agents: dexmetetomidine, propofol, ofirimev
Decrease pressor use
Develop an algorithm for MAC vs. GA and patient selection
We at Scripps Memorial Hospital in La Jolla do most of our transfemoral TAVRs via conscious sedation assuming appropriate patient selection. These patients still tend to be the inoperable patients not cleared for open heart AVR (aortic valve replacement). My techniques and choices for setup have changed over time as I’ve had a chance to fine-tune my plan based on prior experiences with TAVR. Patients typically come to the hybrid room with a 20g PIV placed by the pre-op RN.
4 channel Alaris pump:
dexmedetomidine @ 0.7 mcg/kg/hr until incision –> 0.4 mcg/kg/hr until valve deployment –> off
norepinephrine @ 2 mcg/min (titrating on/off, up/down as vitals suggest)
Initially, I would have the interventional cardiologist setup a femoral venous line since they’re getting access to the groin. However, the cardiologist would use that femoral line for emergent ECMO cannulation and I would lose my venous access and have to depend on a measly 20g PIV. Nowadays, I try for a short 14g or 16g PIV. If I can’t get one, the patient gets an awake right IJ cordis for large venous access.
Hot line fluid warmer with blood-Y tubing: this is for hookup to a large PIV or cordis line
Right radial arterial line
I started only placing right radial arterial lines because there was a case of a dissection and I immediately lost my left radial arterial line and couldn’t do pressure monitoring. I insist on only using the RIGHT radial for my arterial monitoring. Do not let the cardiologist only give you arterial monitoring based on their femoral arterial access. It will only give you intermittent monitoring and there are critical points leading up to the deployment where you need CONTINUOUS arterial monitoring. Therefore, I’ve found the right RADIAL arterial line best for continuous monitoring.
Facemask for continuous oxygen at 10L/mim with ETCO2 monitoring
For trans-subclavian/axillary approach vs. transfemoral approach TAVR, I’ll put in a supraclavicular block right after Cordis/large-bore PIV venous access for patient comfort while still utilizing conscious sedation/MAC.
When the patient gets to the room, transfer patient to OR table. Start IV fluids @ 200ml/hr. Cases that go well are about 2 hours from start to end.
Facemask O2 at 10L/min.
Start sedation: precedex/dexmedetomidine @ 0.7 mcg/kg/hr. Some patients may receive 1-2mg midazolam x 1 and 25-50mcg fentanyl for radial art line placement.
Place right radial art line with lidocaine for skin numbing. Place PIV with lidocaine. If unable to get access for PIV, prep neck –> sterile gown/glove/drapes for U/S guided Cordis placement with lidocaine.
OR staff preps patient. Antibiotics prior to incision.
At incision –> precedex to 0.4 mcg/kg/hr. 25-50mcg fentanyl PRN discomfort. 10-20mg propofol push for discomfort if needed while large sheath placed for valve deployment.
Crossing valve –> BP changes. Manage with volume or levophed.
Don’t treat over-drive pacing too aggressively when the valve is deployed. Typically, once the new valve is in, a little volume will help normalize the BP.
Once valve is deployed, turn precedex off. No other sedation or BP meds needed. Change IVF rate to 50ml/hr.
Patient heads to PACU awake, interactive, and comfortable.
What techniques do you like to do? Any suggestions on a different approach?