ADVANCED CARDIAC LIFE SUPPORT
ADVANCED CARDIAC LIFE SUPPORT …This is absolutely fruitless without basic CPR.
THE TEAM LEADER
There should be one leader to give proper direction in every step. He should supervise the entire operation. Continuous support of ventilation and circulation should be observed by the leader throughout the process of resuscitation. The leader should decide when to terminate the resuscitative measures. All suggestions may be appreciated but cross talks should be avoided.
A team leader should try to find out:-
- What is the nature of the problem, e.g., Asystole, arrhythmia, respiratory failure.
- What is the underlying cause; whether correctable or not.
- What further measures are to be adopted.
ECG monitoring should be initiated with paddles of defibrillator as quickly as possible. It is to be note that in outpatient setting the first rhythm force is ventricular fibrillation in 70%-80% cases and this becomes 50% in cases of inpatients setting.
DEFIBRILLATION AND CARDIOVERSION
To assess the cardiac rhythm ECG monitoring should be done as soon as possible and this can be achieved very quickly by paddles of defibrillator. The most important part of ACLS is defibrillation, because this is the only way to increase numbers of viable survivors.
At times it becomes difficult to distinguish between asystole and fine fibrillation but even then in such conditions defibrillation should be done.
In emergency situations a DC shock 400J is routinely given and to be repeated according to necessity.
This is very important for proper defibrillation. One paddle should be placed on the base of the heart while the other one is placed over left 5th intercostals space over the cardiac apex. Skin resistance should be minimized by electrode gel. During defibrillation no one should touch the patient or the bed. As the patient is unconscious no anaesthesist is required. Shock applied by pressing the button when there will be jerking of the patient’s body. Now response of the shock should be determined and a decision should be made as to restart chest compression and ventilation, to improve the oxygenation and perfusion or to give another shock.ADVANCED CARDIAC LIFE SUPPORT
AIRWAY CONTROL, VENTILATION AND OXYGENATION
As soon as available 100% oxygen should be used. The objective is to maintain an arterial PO2 greater than 60 mm of Hg. Endotracheal intubation may be done by qualified personnel but CPR should not be discontinued for more than 30 seconds for this plea. If endotracheal intubation is unsuccessful for cervical spinal injury or due to upper airway obstruction, cricothroidotomy should be done instead.
DRUGS OF ADVANCED CARDIAC LIFE SUPPORT
In such situations drug therapy means intravenous delivery. IV channels should be kept ready in upper arms. Feroral veins inappropriate and intracardiac routes may be hazardous. Most of the drugs are given as bolus. Isotonic injections, e.g., Epinephrine, Atropine, Lidocaine may be diluted with 10 cc saline and be injected IV or through endotracheal tube into the tracheobronchial vein. Injections should not be delivered in endotracheal tube.
This is used mainly for its o adrenergic rather than B adrenergic agonist properties. Vasoconstriction is extremely useful for coronary perfusion. The dose is 0.5-1 mg, e.g., 0.5- 1 cc in 1: 1000 dilution or 5-10 cc 1 10000 dilution should be given every 5 minutes. The drug may start cardiac contraction and may produce ventricular fibrillation which can be treated by DC counter shock.
Hypoxia in cardiac arrest results in lactic acidosis, Paripasu respiratory failure leads to CO2 retention and respiratory acidosis. It should be noted that acidosis has an inhibitory influence over catechnolamines which in turn lowers the threshold for production of fibrillation. Acidosis also inhibits cardiac contractility. Again Alkalosis prevents O, release from haemoglobin which favours production of arrhythmia. In presence of excellent basic CPR bicarbonate is rarely required. If at all one has to use bicarbonate it should be given after difibrillation and after establishment of adequate ventilation. It may also be used if specific indication, e.g., hypercalcaemia. Sodium bicarbonate 3.75 gm (44.6 meq) should be given IV and repeated every 5 minutes till circulation is restored. A slow infusion of 5% Sodibicarbonate at 100-150 drops per minute is more suitable. PH and PaCO, should be measured frequently. It should not be given in the same IV line with calcium and catecholamine as the former may be precipitated and the latter is inactivated.ADVANCED CARDIAC LIFE SUPPORT
This drug is vagolytic and thus increases the rate of SA node. Due to its vagolytic effect it also improves AV conduction.
Atropine is indicated:-
(i) When there is relative or absolute bradycardia in presence of narrow QRS complex,
(ii) In presence of ventricular ectopics due to bradycardia having symptoms pertaining to bradycardia,
(iii) In presence of hypotension with inappropriate heart rate and in absence of use of negative chronotropic drugs.
The usual dose is 0.5 mg IV repeated at 5 minutes interval. In presence of ventricular asystole 1-2 mg IV should be given. Total dose should not exceed 2 mg. It should be remembered that smaller dose will have a vagotonic effect.
Very high level of serum calcium has been observed after cardiac arrest. Thus unless definite hypo-calcaemia or calcium- channel blocker toxicity is present, it should not be given. Calcium ion enhances ventricular automaticity apart from increasing myocardial contractile force. It may have a profound effect on cardiovascular collapse and may be useful for establishing electrical rhythm when asystole is present. Calcium chloride is injected IV as 10 % solution and repeated at 10 minutes interval if necessary…ADVANCED CARDIAC LIFE SUPPORT
It is an adrenergic stimulator increasing heart rate, cardiac contractility and AV conduction. In presence of bradycardia refractory to atropine while preparation for pacemaker lodgement is being made, this may be used in a dose of 1 mg in 500 ce of 5% Dextrose water at a rate of 3 cc per minute.
Of all antiarrhythmic drugs Lidocaine and Bretylium are best used for ventricular fibrillation but as Bretylium has a hypotensive property Lidocaine is maximally used. Thus when arrhythmia is refractory to Lidocaine one may use Bretylium and Procainamide.
Start 1 mg/kg initially as a bolus and then after 10-12 minutes 0.5 mg/kg may be given IV till a total dose of 5 mg/kg is given. After successful resuscitation as constant infusion 2-4 mg per minute may be continued.
This is best indicated for ventricular fibrillation refractory to DC shock or when Lidocaine has failed. Start with 5 mg/Kg IV and if fibrillation persists for 10-15 minutes, 10 mg/Kg should be given in addition. For recurrent intractable ventricular tachycardia, Bretylium should be given in infusion in a dilution of 1: 4 for over 8 minutes, after which 1-2 mg per minute may be continued.
This is useful in Lidocaine failed cases. The dose is 20 mg per minute until dysrhythmia disappears or hypo-tension Develops or total dose of 1000 mg has been given or ECG shows wider QRS with 50% increase. A continued infusion of 1-4 mg per minute should be continued.
It should be used within seconds of the arrest because it is less likely to be successful when used late and hence in such situation it is not recommended.
This is a consequence of ischaemic heart disease. Before initiating treatment correct hypokalaemia, if it is present. Start defibrillating with 200J and repeat with 200-300J and repeat for 3rd time with 360J, if fibrillation persists.
If above procedure is unsuccessful, start with basic CPR, give epinephrine and repeat it every 5 minutes. Now defibrillate again with 300-360J. If no response, start Lidocaine 1 mg/Kg I. V bolus and defibrillate with 300-360J. If no response, start Bretylium 5 mg/Kg bolus and again defibrillate with 300-360J. At this point one may use bi-carbonate. If still there is no response, give Bretylium 10 mg/Kg bolus and defibrillate with 300-360J.
In presence of VT without pulse, treatment should be same as ventricular fibrillation, If VT is associated with pulse and patient is conscious, attempt to arrest it with Lidocaine, Bretylium or Procainamide. If no response is seen then synchronized cardioversion with 20-100J should be done. If VT is associated with pulse and patient is unconscious cardioversion should be done with 200J after a bolus dose of Lidocaine. If there is no response then Lidocaine, Bretylium and Procainamide should be readministered and cardioversion should be done again with 300J. Once VT is converted to stable rhythm maintenance therapy should be done by above drugs.ADVANCED CARDIAC LIFE SUPPORT
This should be confirmed at two different leads because fine ventricular fibrillation may simulate asystole. When doubt exists treatment for fibrillation should be done. When asystole is confirmed the following are done:-
Oxygen, Epinephrine, Sodi-bi-carb, Atropine, Calcium Chloride may be given. If all fail Isoproterenol infusion should be started as well as temporary ventricular pacing, particularly when P waves are seen in ECG.
ELECTROMECHANICAL DISSOCIATION (EMD)
This is a condition when ECG shows electrical activity but pulse is absent. This may be due to IHD, including infarction, pulmonary embolism, cardiac rupture, pneumothorax, cardiac tamponade, enhanced vagal tone, hypovolaemia, etc. For this, basic CPR, maintenance of ventilation, acid-base balance, epinephrine, calcium chloride may be required. Isoproterenol infusion may be tried when all others fail. CPR is to be continued even if no pulse appears. All other causes of EMD mentioned above should also be treated.