Asystole

Asystole General Information:

Asystole Symptoms:

The immediate identification of Asystole requires the detection of a complete cardiac arrest and a definite rhythm that is flat-lined and in perpendicular leads of 2 numbers. When a rhythm that is bradyasystolic occurs, fainting or lightheadedness often occurs in the affected. If it is an asystolic rhythm and is present for several seconds, the patient will become unresponsive and unconscious. They might take some painful gasps of breath but palpable marginal pulses and noticeable heart sounds are not found. Secondary Asystole conditions are arrived upon due to conditions like suffocation, pulmonary embolus that is massive stroke, hyperkalemia, near drowning experience, stroke, VF or VT complicated by MI leading to Asystole, hypothermia, and narcotic or sedative overdoses leading to a respiratory problem and defibrillation.

Hypothermia is a special condition where aystole is tolerated for a longer time and can be reversed with warming again rapidly while performing CPR – cardiopulmonary resuscitation. When metabolic functions that are cellular are not intact and an impulse that is electrical is not generated then a condition called as primary Asystole is developed. The transmembrane activity is hampered when the cells of the pacemaker are not able to transport the ions because of ischemia. It is also caused due to failure of pacemaker that is implantable. Sometimes, sudden death due to this disease occurs from a cardiac trauma, a local tumor or a congenital heart block.

Asystole Treatment:

The 3 only drugs suggested or up to standard by the AHA (American Heart Association) for adults with Asystole are atropine-0.03mg/kg, epinephrine-0.20mg.kg and vasopressin-40 U. Although, atropine is not recommended for children and infants with asystolic condition it can be recommended for adults having slow rhythms of PEA. If circulation that is spontaneous has not been re-established then vasopressin of 40U can be administered and can also be followed by epinephrine as suggested by the medical practitioner for good results. A recent study conducted on 528 asystolic patients showed that 4 of them survived in the group with standard therapy and 12 with vasopressin survived when discharged. The ACLS 2005 – advanced cardiac life support guidelines have allowed a one time dose of vasopressin 40 U followed by epinephrine as a treatment for VF and Asystole.

When there is a lack of metabolic deficit like impulse generating disorder followed by cardiac arrest Transcutaneous pacing TCP can be used. The main foundation of the emergency treatment involves providing the patient with oxygenation and ventilation through intubation that is endotracheal and circulation is done through CPR, administering TCP and agents that are pharmacologic. A high dose of epinephrine - 0.20 mg /kg improves hemodynamics of the CPR which in turn increases the rate of circulation that is spontaneous.

The drug category comes under agents that are Anticholinergic. On using these agents it enhances activity that is sinoatrial and also improves conduction through the AV or SA nodes by reducing the vagal tone through the muscarinic receptor blockade. This will prove to be effective only if the block site is within the AVor SA node. This therapy is ineffective for patients with block that is infranodal. It increases Mobitz II second-degree block to a higher degree of block almost to a third-degree block. Atropine is an agent that is Parasympatholytic which removes the vagal influence on the AV and SA nodes. It is not effective for a heart block that is third-degree and infranodal. For adults 0.03mg/kg can be given, if IV/IO is not accessible then 2.5 mg can be administered through ET – endotracheal tube, this dose should be followed by a saline flush of 5ml or 5 ventilations, to avoid a paradoxical parasympathomimetic effect that is centrally mediated 1 mg of the dose must be given. In children, it is not recommended for bradyasystolic arrest. For a pulse which is unresponsive to fluids and oxygen for symptomatic bradycardia 0.02mg/kg is to be administered. For children 0.5-1 mg is administered, and adults – 1 to 2 mg.

The drug categories of agents that are Adrenergic are agents that produce the constriction of vascular and skeletal muscles. The drugs that come under this category are epinephrine and vasopressin. Epinephrine or adrenaline can be used for cardiac arrest. It increases the blood flow to the heart and the brain during CPR. During Asystole it enhances automaticity. It is used for bradycardia in children and in adults. 0.01 to 0.20 mg/kg are recommended for adults and 0.10 mg/kg is recommended for children. The drug vasopressin or pitressin contains ADH activity and has vasopressor. It increase water reabsorption into distal renal tubular epithelium and promotes a muscle contraction that is smooth along with vasopressor effects. Vaso-constriction is done in intra-hepatic, splanchnic, cerebral, coronary, portal, pulmonary and peripheral vessels.