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ELECTRICAL CARDIOVERSION

 

 

INDICATIONS:

·         URGENT/EMERGENT

·         conversion of tachycardias with associated serious signs / symptoms (chest pain, pulmonary edema, hypotension, mental status changes)

·         ELECTIVE

·         Conversion of stable atrial fibrillation or flutter of greater than 48 hours duration

·         Consider anticoagulation for at least 3 weeks prior to elective cardioversion to decrease risk of embolization of atrial thrombi

·         Early cardioversion can be attempted if TEE negative for atrial clot, and patient started on IV Heparin, then continue anticoagulation for 4 weeks post-procedure

 

 

(RELATIVE) CONTRAINDICATIONS:

·         Cardioversion is unlikely to be successful and may be harmful in dysrhythmias due to enhanced automaticity (i.e. digoxin toxicity) because a homogenous depolarization state already exists

·         cardioversion is usually not only ineffective but is associated with a higher incidence of post-shock VT/VF.  Medications are usually more effective than cardioversion to control the rate/convert the rhythm.

 

 

MATERIALS:

·         defibrillator

·         many different machines/models

·         you should become familiar with equipment where you are practicing

·         paddles

·         adult size (8-9cm diameter) for patient weight > 10 kg.

·         pediatric size ( 2.2 cm diameter) for patient weight < 10 kg.

·         Electrode pads

·         Self – adhesive

·         Conductive material

·         Gel, paste or pads

 

 

PRE-PROCEDURE PATIENT EDUCATION:

·         Explain procedure indications, expected outcome and possible complications, as well as any alternatives (possible medications without cardioversion) to the patient.

·         Answer any questions the patient may have.

·         Obtain written consent for the procedure.

 

 

PROCEDURE/TECHNIQUE:

·         If time permits and the patient is hemodynamically stable, correct metabolic and electrolyte abnormalities which may be the cause of the arrhythmia.

·         Provide supplemental O2 and obtain IV access.

·         Ensure airway management equipment is readily available (suction, BVM, O2, laryngoscope, ETT, pulse ox, etc.)

·         Bring “code box” to bedside due to potential urgent need for ACLS meds.

·         Strongly consider sedation

·         Turn on defibrillator/monitor


Apply defibrillator monitor cable leads, or pads to patient to determine rhythm

·         Lead placement:  Attach monitor leads (“white on right”, “smoke over fire”) to patient to confirm rhythm

·         “White-on-the-right” will help you to remember the white electrode is placed on the right side of the chest just below the right clavicle

·         “smoke over fire” will help you to remember that the black lead is placed  on the left chest just below the left clavicle, and the red lead is placed in the left midaxillary line below the expected  PMI of the heart

·         electrode pad placement:

·         can be placed as described above for paddles, or

·         anterior pad just to the left of the sternum, and posterior pad on the patient’s back to the left of the spine.  (This technique “sandwiches” the heart between the pads)

·         Engage synchronization mode (press the “sync” button)

·         Look for markers on “R” wave to indicate sync mode activated

·         If necessary adjust monitor gain or change leads to select large enough R waves for sync mode recognition

·         Select appropriate recommended energy level (Initial/subsequent)

·         Atrial fibrillation  (100/200)

·         Atrial flutter  (20/50/100)

·         Atrial tachycardia – other  (50/100/200)

·         Ventricular tachycardia  (50/100/200)

·         Position conductor pads on patient (or apply conductive gel to paddles)

·         Position paddles on the patient (sternum/apex)

·         First (“sternum”) paddle:  to the right of the upper sternum and below the clavicle

·         Second (“apex”) paddle:  to the left of the nipple in the midaxillary line, centered in the 5th intercostal space

·         Avoid placing both paddles next to one another on the anterior chest wall to prevent arching current

·         Ensure “all clear”

·         Press “charge” button on paddle (usually located on “apex” paddle in right hand)

·         Apply firm downward pressure on paddles and press discharge buttons simultaneously after ensuring everyone and equipment is “all clear” from the patient

·         Check monitor, analyze rhythm, and reassess patient

·         If subsequent cardioversions are required, recheck the sync mode, as some defibrillators default back to unsynchronized mode after each shock

 

 

DOCUMENTATION FOR THE MEDICAL RECORD:

·         If the cardioversion was done in a “code” or arrest situation, most facilities have a “code sheet” to be filled out by a member of the code team.  This sheet should be reviewed for accuracy and completeness and signed by the physician (resident and/or attending) in charge of the code.

·         A brief progress note should be written in the chart to include the indications for cardioversion, pre/post-cardioversion rhythm, 12-lead ECG findings, medications given, energy level required, any complications that occurred, patient assessment and outcome, disposition, and the notification of attending physician and family members. 

 

 

COMPLICATIONS, Prevention & Management:

·         Soft tissue injury can occur after repeated shocks.  The presence of liquid (body fluids, medications, or IV fluids) may cause electrical arching thermal burns to the skin and soft tissue and produce ineffective defibrillation by allowing the current to pass across the trunk rather than transthoracic. To minimize this potential complication, ensure that any body fluids or liquids are wiped away from the skin before defibrillation attempts.

·         Myocardial and epicardial injury may result from the electrical current (not direct thermal injury)applied.  Use the minimal recommended energy levels to minimize injury

·         Post-cardioversion cardiac dysrhythmias are possible.  Follow ACLS protocols to manage resulting dysrhythmias.

·         Electrical injuries to health care providers can result if participants remain in contact with the patient during delivery of a shock, because they can serve as a ground for the current discharged.  Fires which can result from sparks in the presence of nitroglycerin patches or ointment, flammable gasses, or an oxygen-rich environment can also be a source of injury to the patient or healthcare providers.  Ensure “all clear” from the patient prior to delivery of shock to avoid these complications.

 

 

ITEMS FOR EVALUATION:

·         Performs accurate patient assessment and recognizes rhythms requiring cardioversion

·         Understands indications / contraindications for cardioversion

·         Educates/prepares patient for procedure

·         Applies and operates defibrillator/monitor properly and safely

·         Completes appropriate documentation for medical record

·         Effectively communicates with patient, family and involved physicians