Pace maker anaesthesia

anaesthetic management in a patient with pacemeker

1. Pacemaker & Anaesthesia Speaker: Dr . Rajesh Choudhuri , PGT Moderator: Dr. V. Majumder , Asst. Prof. Dept of Anaesthesiology

2. History Battery-operated pacing devices were introduced by C. W. Lillehei (a cardiothoracic surgeon) and Earl Bakken (an electrical technician) in 1958 . In 1960, Wilson Greatbatch , an engineer in Buffalo, New York, created the first implantable battery-powered device. I nvention of the implantable cardioverter -defibrillator (ICD * ) around 1980 by Michael Morchower (of Baltimore).

3. 3 Pacemakers Today Single or dual chamber. Multiple programmable features, Adaptive rate pacing. Programmable lead configuration. Internal Cardiac Defibrillators ( ICD) Transvenous leads. Multiprogrammable Incorporate all capabilities of contemporary pacemakers. Storage capacity.

4. 4 Permanent Pacing Indications Complete heart block Chronic Bifascicular and Trifascicular Block. AVHB after Acute MI. 2 nd degree heart block / Mobiz type 2 Hypersensitive Carotid Sinus and Neurally Mediated Syndromes. Sick sinus syndrome( Sinus Node Dysfunction) Stroke A dams syndrome. Indications for ICDs Cardiac arrest due to VT/VF not due to a transient or reversible cause. Spontaneous sustained VT. Syncope with hemodynamically significant sustained VT or VF

5. Pacer malfunction symptoms 1. Vertigo/Syncope *Worsens with exercise 2. Unusual fatigue 3. Low B/P/  peripheral pulses 4. Cyanosis 5. Jugular vein distention 6. Oliguria 7. Dyspnea / Orthopnea 8. Altered mental status

6. Anesthesia for Insertion MAC To provide comfort To control dysrhythmias To check for proper function/capture Have external pacer/ Isoproterenol /Atropine ready Continuous ECG and peripheral pulse. Pulse ox with plethysmography to see perfusion of each complex.

7. Preoperative Evaluation : Indication for implanted pacemaker/ICD Sustained /intermittent tachyarrhythmia or bradyarrhythmias . Heart failure Type of device: Clinical indication of the device Appraisal of patient’s degree of dependence on the devices(for patient requiring pacing for bradyarrhythmias ) Assessment of device function, A preoperative history of vertigo, pre syncope , or syncope in a patient with a pacemaker could reflect pacemaker dysfunction . A 10% decrease in heart rate from the initial heart rate setting may reflect battery depletion. An irregular heart rate could indicate competition of the pulse generator with the patient's intrinsic heart rate or failure of the pulse generator to sense R waves . Continue antiarrythmic drug and other cardiac drugs as mandated Consider Electromagnetic and Mechanical Interference (EMI)

8. Monitoring Manual pulse palpation Pulse oximetry Continuous ECG monitoring Auscultation of heart sounds Intra-arterial blood pressure Investiagtion : Routine investigation along with s. electrolytes/acid –base analysis. Chest xray : Location and external condition of pacemaker electrodes. If bi-ventricular pace maker(position of coronary sinus lead when insertion of central line or PA catheter planned ).

9. Management of a Patient --Intra Operatively Application of magnet over pulse generator of pace maker…no longer an acceptable practice. Results in asynchronous fixed rate.(chance of R on T phenomenon) But Difficult to assess the effect of magnet on cardioverter - defibrilator . Transcutaneous pacing is always kept ready. Rate responsive pacemakers should have rate responsive mode disabled before surgery. Central venous catheterisation : chance of pacing leads dislodgement.

10. Factors affecting the pacing threshold Increase threshold 1-4 wks after implantation MI Hypothermia/Hypothyroidism Hyperkalaemia /acidosis/alkalosis Antiarrhythmics (class 1a,1b,1c) Severe hypoxia/hyperglycemia Inhalational –local anaesthesia Decrease threshold Increases catecholamines Stress,anxiety Sympathomimetic drugs Anticholinergics Glucocorticoids Hyperthyroidism Hypermetabolic status

11. Choice of A naesthesia Technique may not influence directly but physiological changes (acid- base,electrolytes ) & hemodynamic shifts ( heart rate, rhythm, hypertension, coronary ischemia) can change CIED function& adversely effect patient outcome.

12. Effects of Anaesthetic Drugs Drugs that causes hyperkalemia (increases the pacemaker threshold) like sch which also may inhibit a normally functioning cardiac pace maker by causing contraction of skeletal ms groups ( myo potentials) that the pulse generator could interpret as intrinsic R wave. If SCH to be used defasiculating dose of non depolarizing ms relaxants should be given prior to this. Etomidate and ketamine should be avoided as these cause myoclonic movements. Chance of dislodgement of pacemaker leads by positive pressure ventilation or nitrous oxide entrapment in the pacemaker pocket

13. Factors affecting CIED FUNCTION --- Electro cautery / MRI /Radio frequency ablation Effect of MRI on pacemaker Inhibition of pacing Asynchronous pacing Inappropriate defibrillation /complete device failure Shielding reduces problems now a days.

14. Effect of Cautery on Pacemaker Mainly coagulation setting in mono ploar cautery than the cutting. Bipolar & ultrasonic harmonic scalpel less likely, mono polar effects more. Use cautery with low current ,short burst, avoid using in the area of pulse generator and electro leads. U se of cautery at least 15 cm from the pulse generator, 1 sec burst with 10-15 sec gap. Grounding electrodes for electrocautery should be as far as possible from pulse generator.

15. Patient under going lithotripsy keeping the focus of lithotripsy beam away from pulse generator. Radiation field : chance of pace maker failure & runway pace maker.. ECT Therapy : anti tachycardia function should be suspended. Myopotential during seizure may inhibit pacemaker activity. Peripheral nerve stimulators /evoked potential monitors/shivering/medication induced ms fasciculation also cause pacemaker interference. If emergency defibrillation needed ,keep the defibrillator away( 12 cm) from the pulse generator & lead system( antero -posterior direction pads).

16. Post Operative Management Interrogating the device & restoring baseline settings( like anti tachycardia therapy). Cardiac rate ,rhythm monitoring continuously, Hypothermia prevention. Reprogramming.

17. 18 Pace maker failure Failure to pace Failure to capture Undersensing / failure to sense Oversensing Pace maker failure

18. THANK YOU