During transcutaneous pacing, pads are placed on the patient's chest, either in the anterior/lateral position or the anterior/posterior position. The anterior/posterior position is preferred as it minimizes transthoracic
electrical impedance by "sandwiching" the heart between the two pads. The pads are then attached to a monitor/defibrillator, a heart rate is selected, and current (measured in milliamps) is increased until electrical capture (characterized by a wide
QRS complex with tall, broad T wave on the
ECG) is obtained, with a corresponding pulse. Pacing artifact on the ECG and severe muscle twitching may make this determination difficult. It is therefore advisable to use another instrument (e.g. SpO2 monitor or bedside doppler) to confirm mechanical capture. Transcutaneous pacing may be uncomfortable for the patient.
Sedation should therefore be considered. Before pacing the patient in a prehospital setting sedation is recommended by administering an analgesic or an anxiolytic. Prolonged transcutaneous pacing may cause burns on the skin. According to the Zoll M Series Operator's Guide," Continuous pacing of neonates can cause skin burns. If it is necessary to pace for more than 30 minutes, periodic inspection of the underlying skin is strongly advised." It is meant to stabilize the patient until a more permanent means of pacing is achieved. Other forms of cardiac pacing are
transvenous pacing, epicardial pacing, and permanent pacing with an
implantable pacemaker. In addition to synchronized transcutaneous pacing offered by newer cardiac monitor/defibrillators, there is also an option for asynchronous pacing. Sometimes in the prehospital setting a situation may arise where ECG electrodes are not available or something interferes with their adhesion to the patient's skin. In these rare situations where the patient must be paced and there are no other alternatives, asynchronous pacing may be used. Again, this setting should only be used as a last resort due to possible adverse cardiac effects it could cause. ==See also==