MMC R8 Cath Lab / EP Lab TipsUPDATED

Revised March 2017

ICD Procedures Pacemakers & ICDs: Codes & Management
ICD Procedures Percutaneous Atrial Appendage Closure (Watchman)
Bi-Ventricular Pacer/Defibrillator  
Pediatric EP Studies & Ablations  
Ablation for Atrial Flutter  

Ablation for Atrial Fibrillation

A-fib Ablation Checklist

Convergent Hybrid Epicardial/Endocardial Ablation

 
Mitral Valve Clipping for MR  
   

Introduction

The Anesthesia Dept staffs two sites on Thursdays on R8 and/or R9 with a team of one anesthesiologist and 2 CRNAs (residents may sometimes substituted for CRNAs). This increased staffing is occurring in response to a large and sustained increase in the volume of electrophysiological (EP) procedures. 

I have attempted to summarize the approach to the anesthesia care of these EP patients (see below). Although I have attempted to describe a "typical" approach, it is only a guide. Other approaches are surely acceptable and may even be preferable. In addition, other anesthesia staff may have strong, and legitimate preferences for other approaches.

Of note, the cardiologists are very appreciative of our presence. They are eager to hear about any problems that we may be having (e.g., unexplained hemodynamic instability), are eager to help, and have a similar desire for optimal patient outcome. In addition, the cardiologists may have particular insight into the cause of problems (e.g., pericardial effusion) and has powerful diagnostic tools (e.g., fluoro).

-Paul Lennon July 2009


ICD (Implantable Cardiac Defibrillator) Procedures


Procedures: ICD placements, testings, and generator changes. 
Almost all these procedures involve at least one test of the device (i.e., VT/VF is induced and the ICD discharges). The procedure involves accessing the ICD pocket in the subcutaneous space in the upper anterior chest following administration of local anesthesia. The cardiologist typically accesses the central circulation via the subclavian vein and places lead(s) into the right heart. All these devices also have pacing capability. The procedure is usually less than 90 min in duration.

Patients: Patients with poor ventricular function (EF < 30%) or patients with a past history of proven or suspected VT/VF. The overwhelming majority of patients are of the former category (i.e., poor ventricular function), are older, and have multiple medical problems.

Anesthesia care: Typically includes a peripheral IV, BP cuff, an LMA, and inhalational anesthesia. Some staff have a preference for etomidate as induction agent given past episodes of severe hemodynamic instability (e.g., cardiac arrest, PEA) with induction. The advantage of an LMA is the maintenance of spontaneous ventilation; positive pressure ventilation in these patients in often not well tolerated hemodynamically. Inhalational anesthesia often results in hypotension; IV infusion of a vasoactive agent (e.g., phenylephrine, dopamine) may be necessary for blood pressure support. Fortunately, these patients' advanced age and coexisting diseases suggest a reduced MAC. 
Although not typical, placement of an ETT is always an option. (I prefer an ETT in those patients with severe pulmonary insufficiency, morbid obesity, or in instances of a poor LMA seal.) Cardiac arrest in the form of pulseless electrical activity (PEA) can occur for up to ten minutes following an ICD "shock". Although a relatively uncommon event (~1/500), outcome can be poor especially if diagnosis and treatment is delayed. Therefore, frequent BP measurement (i.e., q 1 min) for ten minutes after an ICD "shock" is suggested. 
The cardiologist's administration of local anesthesia is usually sufficient for postoperative analgesia.


Biventricular ICD Procedures


Procedures: Same as ICD procedures (see above) but also require placement of an additional lead into the coronary sinus (accessed from the right atrium). Placement of this lead can be challenging (i.e., require substantial time). This additional lead allows both ventricles to be depolarized simultaneously during ventricular pacing (there is evidence that such simultaneous ventricular depolarization is associated with an increase in EF over time). Procedure times tend to be long (3-4 hours and sometimes longer).


Patients: Patients with poor ventricular function (EF < 30%) who also are pacer dependent or who have a left bundle branch block (LBBB). However, these patients tend to be even "sicker" than typical ICD patients due to advanced, symptomatic congestive heart failure.

Anesthesia care: Similar to ICD patients (see above). However, since these patients tend to be quite sick and procedure times are longer (3-5 hours), I often place an ETT. Sometimes, transition to spontaneous ventilation is well tolerated. However, controlled ventilation may be desirable (e.g., decreased work of breathing). 

The cardiologist's administration of local anesthesia is usually sufficient for postoperative analgesia.


Pediatric EP studies and ablations:


Procedures: Radiofrequency ablation of SVT pathways via femoral IV access. This often occasion requires intra-atrial transeptal puncture to obtain access to the left atrium. Procedure length is typically 3-5 hours.

Patients: Typically healthy older pediatric patients (i.e., ages 10 -16) with a history of proven or suspected SVT. However, these patients (and their parents) tend to be appropriately anxious.

Anesthesia care: Typically a peripheral IV, BP cuff, an LMA, and inhalational anesthesia. I often administer midazolam for preoperative anxiolysis. ETT placement is always an option, particularly if the procedure is lengthy or an LMA is problematic.


Atrial flutter ablations:


Procedures: Radiofrequency ablation (right atrial) via femoral IV access. 
Procedure length is typically 2-3 hours.

Patients: Typical (Maine) adult, usually with normal ventricular function.

Anesthesia care: Typically a peripheral IV, BP cuff, an LMA, and inhalational anesthesia. ETT placement is always an option, particularly if the procedure is lengthy or an LMA is problematic.


Atrial fibrillation ablations: Revised 6/13


Procedure: Radiofrequency ablation of pulmonary veins at their entrance into the left atrium. Access to the left atrium is obtained via femoral vein access and intra-atrial transeptal puncture. Procedure times tend to be long (i.e., 4+ hours). Particular risks include pericardial effusion and formation of a fistula between a pulmonary vein and esophagus (either is bad, particularly the latter). A TEE is performed after induction of anesthesia to rule out the presence of LA thrombus (unlikely). If a LA thrombus is seen, then the procedure is aborted. In some patients, the TEE is performed earlier in the day.

As of September 2012, some electrophysiologists are using cryo-therapy (rather than radio-frequency energy) to ablate a-fib. The anesthesia management is slightly different (see below)

Patients: Typical (Maine) adult, usually with normal ventricular function. 

Anesthesia care: Typically a peripheral IV, BP cuff, ETT, and inhalational anesthesia. As of August 2012, cardiologists are now requesting radial arterial lines on their atrial fibrillation ablation cases. All the necessary equipment and kits should be available on R8. The R8 techs will also be supplying the pressure bag set-ups and will assist you if you so request. Therefore, there should be no need to call the CVAT for assistance.

The anesthetic management for cryo-ablations is slightly different:

  • They still want no muscle paralysis during some of the case, particularly when they are ablating the right upper pulmonary veins. They purposely will pace the phrenic nerve which runs close by. This will effectively pace the diaphragm. The ETCO2 trace will be affected.
  • They don't give any fluid so we're free to mange our fluids just like any other case. It's best to inquire however, because some patients will receive as much as one liter of crystalloid.
  • Pts. may get cold; they actually turned the room temp up today. We monitor the pt's. temp ourselves.
  • Obviously, as part of the "start up" of this process, some things could have been overlooked. Please do not hesitate to contact me (Paul Lennon) with suggestions/observations.

An ETT is preferred due to the case length, need for an esophageal temperature probe (as an early indicator of pulmonary vein to esophageal fistula), and the (unlikely) risk of severe hemodynamic instability due to procedural complications. Cardiologists prefer particularly timely notification of hemodynamic instability (or increase in esophageal temperature) due to a concern that this may be an indicator of a procedural complication. 

See Also more detailed notes on the first case of A-Fib Ablation at MMC, immediately below

Atrial Fibrillation Ablation Checklist

June 2013 Shannon Calvert, Paul Lennon

  ITEM RATIONALE
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Radial arterial line
Major concern is cardiac tamponade (~2% of cases) during the ablation phase. Hypotension (after commencement of ablation) raises a strong suspicion of tamponade. Inform us (cardiology) immediately if hypotension occurs so that we can quickly look for tamponade with our indwelling ultrasound. False alarms are OK. If tamponade occurs, the arterial line will also be crucial in management (on R8 and/or in the OR).
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Use an endotracheal tube
Airway control and occasional breath holding will be required
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Muscle relaxants...
...must be largely gone by 45 minutes after intubation: we need to identify the phrenic nerve via nerve stimulation.
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Patient movement...
...during the procedure can substantially complicate and prolong the procedure (movement will change the atrial map and may require redo of this mapping).
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limit IV fluids
We give substantial amounts of IV fluid as part of the ablation procedure. Therefore, please attempt to limit your IV fluids.
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Heparin...
...will be administered by cardiology.
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Antibiotics...
...are not routinely required.
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Communication
frequent and open frequent and open communication is strongly encouraged.

 

 

 


Anesthesia for Ablation of Atrial Fibrillation
10/17/2007 (Revised 5/2009)- VerLee

Indications:

Initially, these were "young", otherwise healthy, patients who don't want to be on anticoagulants and rate control for rest of their life. Since 2009, we are seeing sicker patients, with CHF hx.
Paroxysmal AF more successful to ablate vs. chronic AF
 

Approach:

-TEE done first to confirm /delineate anatomy (?PFO, etc.)
    (if case booked for noon or after, the TEE is sometimes done in the AM; if so, you may consider 
     changing your airway management to a LMA) 
-cath via groin(s)
-Cardiologist makes trans-septal puncture to gain access to pulmonary veins (site of origin of AF)
-intracardiac echo to make 3-D map of Left Atrium, to chart ablations 
-once map is made, patient must be still, or reference points lost and map must be recreated.
-patient heavily heparinzed (ACT 350-450). Heparin management by Cath Lab nurses.

Risks:

1) Tamponade: burn hole through atrial wall,  with high heparinization
2) Aortic puncture: (mis-directed trans-septal puncture)
3) Stroke: from emboli

Anesthesia Considerations/Concerns:

1) Duration: eventually 3-4 hours, but initially 6-8 hours
2) in an ideal world, Sedation is preferred  by cardiologist, to monitor presence of chest pain and/or mentation. In a real world, these patients invariably go to sleep.
    
3) Airway Considerations:
   a) TEE Done at outset (if case booked for noon or after, the TEE is sometimes done in the AM; if so, you may consider changing your airway management to a LMA) 
   b) Esophagus must be delineated radiographically; esophageal temp probe is usually sufficient (they will ask you to adjust the position for optimum temp measurement during ablation)
   

For all the above reasons, the cardiologist was easily persuaded to allow me to intubate and ventilate this patient. Maybe in the future we might consider a pro-seal LMA.

Other notes:

-The ablating catheter is saline-cooled (15-30cc/minute). "Waste" saline becomes intravascular, adding 2000-3000 cc to fluid load over the course of the case. Diuretics may be necessary.

-Hypotension is the cardinal sign of bleeding or tamponade, and communication between anesthesiologist and cardiologist is essential. There are times when the stimulus of the procedure is relatively high (TEE placement, some stages of the ablation), and some times when there is virtually no stimulus, but you still need to keep the patient asleep, so neosynephrine is necessary. So the key is a heightened awareness to hypotension: is it anesthesia, blood loss, or tamponade?

-If tamponade DOES occur and is diagnosed, the procedure would be stopped, heparin reversed, and TEE-guided pericardiocentesis done.

-Ironically, many patients arrive to the cath lab in sinus rhythm but leave in Atrial fibrillation (something to do with edema and irritation), only to revert to SR after a couple of days.
-About a third of patients return within  six-months for a touch-up.

Addenda:

2/27/08: Denise LaRue had a patient flip into rapid Afib, with marked hypotension. Rather than tank the patient with fluids or squeeze with Neo, she told the cardiologists, who administered Ibutilide which quickly converted the patient to sinus rhythm. Her case also lasted 6 hours, and she used GA with an LMA for the Airway.

 

References

Endovascular Ablation of Atrial Fibrillation (Review), Anesthesiology V120, No.6, pp1513-19, 2014

The First Atrial Fibrillation Ablation 
at MMC October 17, 2007

Six EP cardiologists in attendance!

 


Mitral Valve Clipping (for Mitral Regurgitation)

information coming.