Cardiac Pacing

imagesHemodynamic instability (presyncope, angina, altered mentation, pulmonary edema) secondary to:


   imagesBradydysrhythmias:


      imagesSinus bradycardia


      imagesSinus node dysfunction


      imagesAtrioventricular (AV) node conduction blocks (second and third degree)


      imagesAcute myocardial infarction with bifascicular block, alternating bundle branch block, new left bundle branch block (LBBB), escape rhythm <40 bpm


      imagesMalfunctioning permanent pacemaker


      imagesElectrolyte/metabolic disturbances (i.e., hyperkalemia) if medical therapies fail or are unavailable


      imagesPost–cardiac surgery (i.e., valve replacement)


      imagesThoracic trauma (i.e., cardiac contusion)


      imagesOther (i.e., lyme carditis, endocarditis)


   imagesTachydysrhythmias (overdrive pacing, typically transvenous only):


      imagesSupraventricular tachycardia (SVT)


      imagesVentricular tachycardia (VT)


imagesTransvenous Pacing—same as above, but also including:


   imagesFailure or nontolerance of transcutaneous pacing


   imagesBridge to permanent pacemaker placement


   imagesHigh risk of progression to complete heart block


   imagesOverdrive pacing


CONTRAINDICATIONS



imagesAbsolute


   imagesAsymptomatic, stable rhythms (i.e., first-degree AV block)


   imagesProsthetic tricuspid valve (transvenous only)


imagesRelative


   imagesSevere hypothermia (may be physiologic bradycardia; can induce fibrillation)


   imagesBrady-asystolic arrest >20 minutes


   imagesDrug-induced dysrhythmias (although can be utilized as last resort if antidote fails)


TRANSCUTANEOUS PACING PROCEDURE



imagesLandmarks


Pacer pads should preferentially be placed over the precordium anteriorly and in the interscapular paraspinous region posteriorly. Anterolateral pad placement is also acceptable.


imagesSupplies


   imagesCardiac monitor with pacemaker capabilities (if electrocardiogram [ECG] monitor is not part of the pacer unit, a separate monitor and adaptor will be required)


   imagesAdhesive pacing pads


   imagesECG electrodes


   imagesSafety razor


imagesTechnique


   imagesPreparation


      imagesIn conscious patients, reassurance and explanation of the procedure, including expectations for discomfort, are extremely important


      imagesRemove excess hair if time permits


      imagesContinuous cardiac and pulse oximetry monitoring, intravenous access, and bedside capability for resuscitation, including airway management, defibrillation, and arrhythmia treatment, should be at the bedside before initiation


   imagesPacer/Electrode Placement


      imagesPads are placed as shown in FIGURE 9.1


      imagesAnterior chest pacing pad (negative charge electrode) is placed over the point of maximal impulse


      imagesIf access to the posterior chest wall is limited or difficult, posterior pacer pad may also be placed in cardiac apex/base position (identical to electrical cardioversion placement)


      imagesECG electrodes should be placed in limb lead positions for monitoring


   imagesPacing


      imagesIdentify pacemaker mode on equipment and turn to “on”


      imagesSet heart rate to 70 bpm


      imagesPlace and maintain one hand in pulse-check position (radial, femoral, or carotid) or observe noninvasive or invasive blood pressure response


      imagesIn bradyasystole and unconscious patients, set current to 150 to 200 mA and lower in 10-mA decrements; set current at the lowest level that will consistently achieve mechanical capture


      imagesIn stable and conscious patients, set current to 10 mA and raise in 10-mA increments until mechanical capture is achieved


      imagesObserve cardiac monitor for pacemaker spikes and electrical capture—“electrical capture” refers to narrow pacemaker spikes followed by typically wide ventricular complexes


      imagesMonitor constantly for “mechanical capture”—a palpable arterial pulse induced by pacemaker discharges or perfusing blood pressure by noninvasive or invasive blood pressure monitoring


      imagesTitrate sedation/analgesia/anxiolysis to allow for tolerance of ongoing pacing


      imagesFailure to achieve mechanical capture should prompt immediate preparation for transvenous pacer placement


imagesComplications


   imagesUnrecognized ventricular fibrillation


   imagesLocal discomfort


   imagesCutaneous injury



images


FIGURE 9.1 Proper placement of transcutaneous pacing electrodes. (From Morton PG, Fontaine DK. Critical Care Nursing. 10th ed. Philadelphia, PA: Wolters Kluwer Health; 2012.)


SAFETY/QUALITY TIPS




imagesProcedural


   imagesThe most common causes of failure to capture in transcutaneous pacing are improper electrode placement or large patient size


   imagesFor many patients, adequate amperage will not be possible without aggressive sedation/analgesia


imagesCognitive


   imagesCompared to transvenous pacing, transcutaneous pacing is painful and ineffective. Transcutaneous pacing should be thought of as a brief bridge to transvenous pacing or correction of the underlying disorder.


   imagesElectrical capture is not mechanical capture, and mechanical capture is what counts. Once electrical capture occurs, mechanical capture must be immediately verified using pulses, invasive arterial pressure monitoring, ultrasound, or (most conveniently) pulse oximetry.


   imagesBe careful not to mistake ventricular fibrillation or tachycardia for a paced rhythm

Only gold members can continue reading. Log In or Register to continue

Aug 9, 2016 | Posted by in EMERGENCY MEDICINE | Comments Off on Cardiac Pacing
Premium Wordpress Themes by UFO Themes