The working principle and symptoms of defibrillator
Electrical defibrillation and cardioversion is to allow a very high voltage, very short time, and very small flow of current to pass through the fibrillating heart, so that the myocardial fibers are depolarized at the same time, and then repolarized at the same time, so as to restore organized and coordinated contraction .
Ventricular fibrillation refers to the irregular and disordered depolarization and contraction of myocardial fibers. The mechanism is not yet fully understood, and may be related to impulse formation disorder or impulse conduction disorder. It is a serious and fatal arrhythmia. Hypoxia, ischemia, acidosis, and electrolyte disturbances can all lower the threshold of ventricular fibrillation.
Defibrillator indications:
1. Ventricular fibrillation or ventricular flutter.
2. Ventricular rate> 152 beats/min, causing significant hemodynamic changes, accompanied by acute myocardial infarction, shock, heart failure, Al-Syndrome, etc., paroxysmal ventricular tachycardia that is ineffective in drug therapy.
3. Atrial fibrillation.
4. Patients who still have atrial fibrillation after surgery for mitral valve disease for more than 2 weeks.
5. Hyperthyroidism has been controlled by drugs but still has atrial fibrillation.
6. Patients with atrial fibrillation after recovery from myocarditis and pulmonary embolism.
7. Those who have sustained fibrillation for a long time and whose heart rate is difficult to control with drugs.
8. Heart failure accompanied by tachycardia atrial fibrillation, whose heart rate is difficult to control with drugs.
9. The onset time of atrial fibrillation <1 year (generally 3-6 months left atrium inner diameter <45 posts 1, cardiothoracic ratio 55%.
10. Pre-excitation syndrome with frequent atrial fibrillation, and the drug treatment is ineffective.
11. Atrial flutter wave>250 times 7 points, 1:1 atrioventricular conduction and drug therapy is ineffective.
12. Patients with paroxysmal supraventricular tachycardia with obvious hemodynamic changes that are ineffective in drug treatment.
13. Pre-excitation complicated by supraventricular tachycardia with ventricular differential conduction, or supraventricular tachycardia with differential conduction, whose nature is difficult to judge for a while.
Defibrillation steps:
1. Assess the patient's ECG type before defibrillation.
2. Cut off AC power and use DC power.
3. Spread the conductive paste evenly on the surface of the electrode plates on both sides, and turn on the defibrillation system to select energy.
4. Put the electrode plate in place and make it fully contact the skin.
5. Instruct other personnel to leave the bed and the patient's limbs to prevent electric shock.
6. Press the "CHARGE" button to charge. After the charge is fully reported, press the "DISCHARGE" discharge button at the same time on both sides, and the defibrillation limbs are discharged to complete the electric transfer rhythm.
7. After the discharge is over, the electrode plate still cannot leave the patient's skin, and the patient's ECG changes during the whole conversion process can be recorded completely.
8. After the defibrillation is completed, wipe the electrode plate, put it back in place, and place the energy selector button in the monitoring position.
