Cardiac Respiratory Arrest (PART 3)

ONLY four factors have been shown to be a mayor benefit in successful resuscitation from cardiac arrest:(1)


Time,arificial ventilation and cardiac massage,defibrillation and adrenaline (Atkins 1986).


The critical parameter  for restoring spontaneous circulation is development of adequate coronary perfusion pressure(CPP).(7)


In human,return of circulation requires that developed CPP exceeds 15-20 mmHg.(7)


Adrenaline with its alpha adrenergic properties ,make  peripheral vasoconstriction leads to an increase in aortic pressure during relaxation phase of closed chest compression,causing an increase in coronary perfusion pressure and coronary blood fllow(Michael 1984).


The ability of adrenaline to increase the amplitude of VF (beta adrenergic effects) make defibrillation easier but the beta adrenergic effects of adrenaline are potentially deterious during cardiac arrest,can increases oxygen consumption and decrease the endo/epicardial blood flow does not improve the oxygen supply/demand ratio (Ditchey 1984).


On the otherhand adrenaline has been shown to improve cerebral perfussion during closed chest massage in animals an effect not show with phenylephrine or methoxamine(Holms 80).


In summary the effectiveness of adrenaline during CPR probably due to reduction in myocardial ischaemia because of improved blood flow caused by the raised aortic pressure during closed chest massage,other vasopressor should be useful for augmenting coronary perfusion pressure (CPP) but lack prospective data.(7)    


All drugs therapy in cardiac arrest can be devided into three categories : pressors,antidysrhythmics and metabolic drugs.
Adrenaline also to convert fine fibrillation to a coarse fibrillation,to improve the coronary perfusion and to increase myocardial contratility.


In pediatric patients adrenaline is indicated for the treatment of symptomatic bradycardia ascociated with poor systemic perfusion or pulseless arrest,administer adrenaline every 3 to 5 minutes during arrest.In neonates may be administered via umbilical venous catheter if rapidly placed, but adrenaline should not be delayed,and may be administered via the ET as an alternative.(5)
The dose via either route is 0,01 to 0,03/kg of the 1;10.000 dilution or adrenaline 1cc 1:1000 dilute to 10 ml and give 0,1 ml/kg iv(5)


Isoprenaline should never be used in cardiac arrest,as a pure beta adrenergics it increases myodial oxygen consumption while reducing diastolic pressure and coronary blood flow.(1) 


Because of its potentially deterious effects,CaCl2 should no longer be used during CPR unless spesific indication exist.If the arrest is precipitated or contibuted by severe hyperkalemia, severe hypocalcemia or calcium channel blockers overdose,calcium may prove useful.(1)


The usual dose is 2-4 mg/kg of the 10%% solution administered slowly intravenously and repeated 10 minutes intervals as deem necessary. Although some animals studies appear promising there is no conclusive evidence that calcium channel blockers will improve the neurological outcome from cardiac arrest.


The known effects of vasodilatation and negative inotropism and dromotropism make the use of these agents in ardiac arrest questionable.Consequently calcium antagonist cannot be recomended for use during CPR in the present state of knowledge.(1)


In recent years,however a better understanding of mechanism of cell damage,high developed with anoxia or ischaemia,cellular phosphate energy stores are rapidly depleted;allowing a large shift of calcium into cells.Because of this increase in intracellular calcium.It has been suggested that additional administration of calcium during CPR is useless or worse than useless.


In the vascular smooth muscle the inflow of calcium results in vasocontriction and this may impede reperfusion of heart and brain.(1)


It has been reported the liberation of CO2 following administration of bicarbonate causes paradoxical CNS acidosis,presumably because CO2 readily diffuses across the blood brain barrier (BBB) while bicarbonate diffuse more slowly(Bereng Wolk and Kellip 1975). It is not appropriate to treat respiratory acidosis with bicarbonat natricus especially since elemination of CO2 during CPR is seldom difficult. Metabolic acidosis as indicated by serum bicarbonate or blood lactate levels,develops very slowly during cardiac arrest and CPR in both animal and humans (Weil et al 1986).


More recent studies suggest that bicarbonate does not improve the success od defibrillation or resuscitation (Minuek and Sharma 1977,Guerci et al 1986).


Hypernatremia and hyperosmolarity cause by bicarbonate natricus administration are frequent during and following CPR and are associated with a poor oputcome (Mattar et al 1974).


It is probably should not be used during CPR unless a known pre existing severe metabolic acidosis and blood gases indicate a severe metabolic acidosis(very low serum bicarbonate).(1)


Bicarbonate can be used to reverse metabolic acidosis or eithe electrolyte problems when they are recognized,however there are no data to support the  rutine use of these drugs for all patients.(7)


Acidosis is managed with ventilation and volume replacement.(5)


Only amiodaron has clinical data supporting its use during VF that persist after rescue shock, Anti dysrhythmic druga are useful for preventing refibrillation in all successfully defibrilated patient not for terminating VF.(5)


Aminophyline is antagonist adenosine released during ischaemia but adenosine hypothesized to suppress cardiac electrical activity.(7)


The high likehood of an acute coronary syndrome in the patient suffering cardiac arrest should prompt consideration of anti platelets therapy,anti coagulation,beta blockade and nitrate during post resuscitation care. Unless clearly non cardiac etiology for cardiac arrest is evident acute coronary angiography may reveal and indication for angioplasty,thrombolysis or other
reperfusion therapy. Early angioplasty or reperfusion therapy is associated with improved survival and outcome.Among out of hospital patients as many as 66% have primary cardiac disturbance. For in hospital patients experiencing cardiac arrest dysrhythmia and cardiac ischaemia account for 59% of events.(7)


If  ROSC is successful :(6)


1. Continue oxygenation,ventilate if necessary and establish infus line for rapid giving drugs.
2. Treat hypotension with inotropic and vasoactive 
    drugs(adrenaline,dopamine,dobutamine)
3. Correction of electrolyte,fluids and  blood glucose. 
4. Becareful with possibly recurrent of cardiac arrest.
5. Treat the arrhythmia.
6. Monitor in ICU.


When there is intractable cardiac arrest probably caused by:(6)


4 H :Hypoxia,Hypovolemia,Hyperkalemia,Hypothermia.
4 T  :Tension pneumothorax,Tamponade of cardiac,thromboembolus of lung,Toxic overdose MA Massive myocard infarct, and Acidosis.


If after ROSC,recurent cardiac arrest :


1.Follow initial algorhytm
2.If necessary ,DC shock 360 J is given and followed with CPR.


TERMINATION OF CPR :(2)


Resuscitation is considered unsuccessful if signs of death of heart and brain are present after one hour of continous CPR effort.   


A.Signs of cardiac death


1.Absence of electrical activity of the heart
2.Slurring and widening of the QRS complex
3.Persistyent fibrillation with slowing and loss of amplitude.


B. Signs of CNS death


1.No breathing
2.Unresponsiveness
3.No movement
4.Absence of reflexes
5.Fixed and dilated pupil,not responding to a direct light,
6.Isoelectric EEG


SUMMARY :


It is frequently difficult to determine wether respiratory arrest precedes or follows circulating arrest in any particular patients. Wether the initial event,however,is the cessation of circulation or of respiration,tissue hypoxia occurs rapidly.


The initial goal of therapy is oxygenation of the brain,the second goal is restoration of circulation and in addition the underlying conditions must be corrected. 


There are five steps in prevention of biological death from sudden cardiac arrest :


1.Rapidly recognized cardiac and respiratory arrest singly or combination.
2.Immediately institute artificial ventilation.
3.Quickly provide techniques that artificially circulate blood.
4.Promptly administer appropriately drug therapy
5.Apply post resuscitative care procedures designed to minimize the deterious effect of the arrest.


During the first few minutes after non asphyxial cardiac arrest the blood oxygen content remain high and myocardial and cerebral oxygen delivery is limited more by diminished cardiac output than a lack of oxygen in the lung ,therefore chest compression is more important than ventilation. For this reason and to emphasize the priority of chest compression it is recomended that in adult CPR should start with chest compression rather than initial ventilation.


REFERENCES :


1. Otto W.Charles,Nunn F.J,:Cardiopulmonary resuscitation of the adult in Textbook of General Anaesthesia,fifth edit,Butterworth,London,Boston Singapore,Sydney,1989, pp1333-44.


2. Snow J.C. : Cardiac arrest and cardiopulmonary resuscitation,Handbook of Manual Anaesthesia, Asian Edition,Little Brown and Company Boston,Igaku Shoin,Tokyo,1977, pp 61-73.


3. Thornton L.Harry : Cardiac arrest and Resuscitation,in Texbook of Emergency Anesthesia,second edit,Edward Arnold Publishers,Ltd 1974, pp 464-75.


4.  Rilex L.Joseph,Ravin BM : Cardiopulmonary Resuscitation in Textbook of Problems in Anesthesia,Little Brown and Company,1981,pp 120-27.


5.  Zimmerman,Taylor W.R> : Cardiopulmonary Resuscitation in Textbook of Fundamental Critical Care Support,Course Syllabus Editorial Committee Medicine,USA 1996 pp 16-24.


6. Modul Workshop CPR,Guidlines 2005,Department of Anesthesiology & Reanimation, Sutomo Hospital -Airlangga University,Surabaya,Indonesia December 2006.


7.Pint P.Mitchell,Abraham E. :Cardiopulmonary resuscitation in Textbook of Critical Care 5th edit, Elsevier Saunders, Philadelphia,Pensylvania,2005 pp 311-4.

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Cardiac Respiratory Arrest (PART 2)

THERAPY


A.The initial goal of therapy is oxygenation of the brain.
The second goal is restoration of circulation. In addition the underlying conditions must be corrected(2).


1. CPR is not indicated for all patients,natural death in the aged or the terminal stages of chronic illness should not be reversed in this manner.


2. CPR should be performed in cases of reversible unexpected death.       


That occur as a result of myocardial infarction, general and local anesthetic drugs,electric shock,cardiac catheterization or suffocation.


OLD GUIDELINES :


B. Emergency CPR includes the following ABCD steps which should always be started as quickly as possible (2)  
          
1.A ----(Airway)
2.B-----(Breathing)
3.C-----(Circulation)
4.D-----(Drugs and definitive therapy)

5. In a witness cardiac arrest when treatment can be initiated within one minute of the arrest the ABCD sequence should include use precordial pump.


1.AIRWAY : (A)(2)


Time is the critical factor,establishment of an airway as soon as possible. To make the airway clear and clear the airway.      


Artificialventilation and circulation must be initiated within 2-4 minutes.


a.Immediate opening the airway


This can be easily and quickly by tilting the patient brow(head) backward as fare as possible. But in newborn not too excessive that worsen airway obstruction because the neck is flexible.                                                                  


Many times this manuver can resume breathing spontaneously. 


The rescuer places one hand beneath the victim's neck and the other hand on the victim's forehead to carry out head tilt. Then the neck is raised by rescuer with one hand and the head is tilted backward by pressure with the other hand on forehead, this effort raised the tongue away from the back of the throat, this relieved anatomic obstruction of  
the airway created by the tongue dropping against the back of the throat.


b. If head tilt not successful in opening the airway satisfactorily additional forward displacement of the lower jaw, jaw thrust, maybe necessary but not recomended for the lay people.


c.This can be done by triple airway maneuver :   


1.The rescuer places his fingers behind the angles of the patient jaw and forcefully displaces the mandible forward.
2. He tilts the head backward.
3. He uses his thumbs to retract the lower lips to allow the patient to breath through the mouth and nose.


2.BREATHING (B):


If the patient does not promptly resume spontaneous breathing after the airway is opened, artificial ventilation must be started immediately by mouth to mouth or mouth to nose or mouth to mask breathing.


After opening the airway by tilting the head backward and displacing mandible forward, clearing the mouth of secretions, and beginning mouth to mouth ventilation.Keep the head tipped, and close the nose to keep air from escaping by squeezing between the left thumb and index finger.(3)


Take a deep breath and cover the patient's mouth with rescuer's mouth.


Give 2-4 big breaths as rapidly as possible without allowing time for the lungs to collapse between breaths.(4)


But in young children and infant ventilates with exhale volume smaller than an adult.


And in newborn exhale with a mouthful volume is adequate  


There after two breaths are interposed between every 30 chest comppression (3).


In children both mouth and nose are covered by the rescuer's mouth and distension of the stomach is prevented by epigastric pressure with the right hand,the chin being held forward with the left.(3) 


There is enough oxygen (16%) in expired air to secure oxygenation of a patient's circulating blood, by doubling normal tidal volume the rescuer increase the expired oxygen to 18%. During CPR, cardiac output(CO) is (25-30)% of normal so oxygen uptake from the lung and CO2 delivery 
to the lungs are also reduced. As result low minute ventilation (lower than normal tidal volume and respiratory rate) can maintain effective oxygenation and ventilation during CPR.


It is also recognized that rescuers are frequently unwilling to carry out mouth to mouth ventilation for a variety of reasons including for infection and distate for the procedures. For these reasons and to emphasize the periority of chest compression it is recomended that in 
adults, CPR should start with chest compression rather than initial ventilation.(Guidelines 2010) (6)


Alternative methods :


a. A self filling non rebreathing bag and wellfitting anesthesia mask,with oxygen supplied from a cylinder of compressed oxygen may be used as soon as they are available/will add the efficiency and convenience of 
resuscitation.(2,4).


b. Endotracheal intubation must be carried out at the earliest possible moment but not before ventilation is produced for a few minutes by another methode.


Intubation should be performed by trained personal,with a cuffed endotracheal.Tube permits easy tracheobronchial toilet, facilitates the connection to a mechanical ventilator, prevent gastric dilatation and regurgitation and decrease dead space.(4)


c. An emergency tracheostomy is indicated when an adequate airway cannot otherwise be effective.


Alternative methodes are :


1.Crycothyrotomy  
2.Transtracheal catheter ventilation or oesophageal obturator airway.


d. In a patient with a laryngectomy,direct mouth to stoma artificial respiration must be carried out.The head tilt and jaw thrust are unnecessary.


During artificial ventilation the following adverse effects may take place :


1.Inflation of the patients stomach with air,followed by regurgitation and/or transmission of infection to the rescuer.


These may occur when there is no tracheal tube in place.


2.Rupture of the patient's lungs.


3.ARTIFICIAL CIRCULATION: (C)


A search for a pulse should always be made following artificial ventilation and before starting sternal compression.


Artificial circulation can be carried out by external cardiac  compresision.    


Which must be started at once because anoxia may cause irreversible damage to the brain after 4 minutes; if resuscitation is successful the patient will probably remain decerebrate.(4)


Proper application of external cardiac compression requires that the patient be in horizontal position and on a firm surface.


Application of pressure must be restricted to the mid of the sternum not half lower of sternum especially not over the xiphoid process to obtain maximum compression of the heart to minimize the dangers of fractured ribs and damage to the liver.


The heel only one hand is placed in the center of the chest over the mid of sternum and the heel of the other hand is placed on top of heel of the first hand. It is very important that fingers be kept elevated at all times and not allowed to touch the chest wall.(4)


Adequate force must be exerted vertically downward to move the lower sternum 4-5 inches toward the vertebral collume, forcing blood into the pulmonary and systemic arteries but for infants and young children, less pressure is required. Following sternal compression the sternum is 
released,and one cycle is repeated.


When the pressure is released,the chest expands and the heart fills with oxygenated blood which is circulated through the tissues with the next compression of the heart. 


Pressure with the finger tips alone on the middle of the sternum is recomended for infants. For children up to 9-10 years of age the use one hand is considered adequate.The compression rate should 100 times perminute with 2 ventilation every 30 compression wether there are one or two rescuers of infant, child or adult is recomended. In the patient trachea has been intubated,the compression rate can be 80 times perminute no pause in compression should be made for ventilation. Synchronizing ventilation between compression is also unnecessary.(2)


Under optimal condition external heart compression produces only 30-40% of the normal amount of blood flow. 


During the first few minutes after non asphyxial cardiac arrest the blood oxygen content remain high and myocardial or cerebral oxygen delivery is limited more by diminished cardiac output than a lack of oxygen in the lungs.Ventilation is therefore, initially less important than chest compression or compression is the first step.( C,A,B )


So initial steps of resuscitation may include for the nonasphyxial cardiac arrest :
Guidlines 2010  : 


1.Cardiac compression 30 times (C)
2.Opening the airway and clear the airway.(A)
3.Giving two breaths using compression ventilation ratio of 
   30:2 (B)D


Main changes in adullt basic life support (BLS)---> guidelines 2005.(6)


- Start CPR when victim is unresponsive and not breathing normally agonal gasp are common in the early stages of cardiac arrest.


- Airway ---> tracheal intubation (A)
- Breathing --- AMBU/Ventilator/O2 (B)
- Circulation --- Cardiac compression (C)
- Defibrillation (D)


Shockable rythm are Venricular tachycardia(VT-pulseless),Ventricular fibrillation (VF). Non shockable are Asystole and Electro mechanical discociation EMD)or Pulseless electro activity (PEA).


Automatic External Defibrillator)(AED) :


Public Access Defibrillation (PAD) Program are recomended for the locations where the expected use of an AED for witnessed cardiac arrest exceeds once in 2 years.

A single shock is delivered immediately followed by two minutes of uninterrupted CPR without a check for signs of life or a pulse.


If VF appears give the first  shock recomendation for higher energy (360 Joule) when using monophasic waveform, immediately begin chest compression.


Don't interrupt chest compression to check rhythm or pulse until 5 cycles or 2 minutes of CPR are given.


Biphasic : Monophasic  ( 96% vs 54% )


When biphasic is given before 5 minutes > ( 50- 70)% probably recovery of spontaneous circulation (ROSC).


Main changes in AED :


PAD programmes are --> A single defibrillatory shock (at least 150 Joule)(biphasic) or 360 Joule(monophasic) is delivered immediately followed by two minutes of uninterrupted CPR without a check for termination of VF or check for signs of live or a pulse.


                   CARDIAC ARREST
                                  I
               ------------------------------
              I                                           I
         unwitness                               witness
              I                                           I
         CPR 2 min                          single shock
              I                                    contnued with
          evaluate                             CPR 2 min -----> evaluate
              I                                           I
   -------------------->            <---- ------------ unshockable        unshockable             shockable
          I                             I                                               I                                                                                                                 CPR 2 min                single shock                         CPR 2 min c            
adrenaline                continued with                     adrenaline                                          
                                  CPR 2 min                                      I?                               
          I ?                          I?                                                                                                                                 
                               


Main changes in Adult Advance Life Support (6)
-----------------------------------------------------------
1. CPR before decfibrillation
2. Defibrillation strategies
3. Fine VF
4. Adrenaline
5. Anti arrhythmia drugs
6. Thrombolytic theraphy for cardiac arrest
7. Post resuscitation care.--therapeutic hypothermia.


CPR before defibrillation :


Unwitness : Give CPR 2 minutes about 5 cycles at 30:2 before defibrillation dont delay defibrillation if an out of hospital arrest is witnessed by a healthcare professional. Dont delay defibrillation for in hospital arrest.


Defibrillation strategy :


Treat VF/pulseless VT with a single shock followed by immediate resumption of CPR ( 30 compression to 2 ventilation). Do not reasses the rhythm or feel for a pulse. 


After 2 minutes of CPR check the rhythm and give another shock (if indicated).


The recomended initial energy for biphasic defibrillators is 150-200 J. Give second and subsequent shocks at 150-360 J. The recomended energy when using monophasic defibrillators is 360 J for both the initial and subsequent shocks. The children 2 joule/kg.


Fine Fibrillation :


If there is doubt about another the rhythm is asystole or fine VF do not attempt defibrillation,instead,continue chest compression and ventilation.


For VF/VT give adrenaline 1 mg iv if VF/VT persist after a second shock. Repeat the adrenaline every 3-5 minutes thereafter if VF/VT persist. For Pulseless electrical activity(PEA)/asystole,give adrenaline 1 mg iv as soon as intravenous access is obtained and repeat every 3-5 min thereafter up to return of ROSC is achieved.


If VT with palpable carotid pulse give lidocaine 1 mg /kg iv or amiodaron 300mg. Pulseless VT give a single shock 360 J immediately CPR 30:2 in 2 minutes. Lidocaine 1-1,5 mg/kg every 3-5 minutes maximal 3 mg/kg in 1 hour.


INTERNATIONAL LIAISON  COMMITEE ON RESUSCITATION (ILCOR) guidelines 2005 (6)


1. Adrenaline 1 mg iv repeated every 3-5 minutes.


2. Amiodaron 300 mg iv bolus,if VT/VF persist after 3 shocks. Doses of 150mg may be given for recurrent or refractory VF/VT followed by an infusion of 900 mg over 24 hours.


3. Lidocaine 1 mg/kg, iv if amiodaron is not available,do not exceed a total dose of 3 mg/kg during the first hour. Do Not give lidocaine if amiodaron has already been given. Atropine,adrenaline and lidocaine may be given intravenously,intratracheal or transtracheal the dosis 3-10 times intraveneously or intraosseus but Not intra cardiac.

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Cardiac Respiratory Arrest (PART 1)

INTRODUCTION :


Cardiopulmonary arrest is the sudden,unexpected cessation of respiration and functional circulation.(2)


It is frequently difficult to determine wether respiratory arrest precedes or follows circulatory arrest in any particular patients wether the initial event,however,is the cessation of circulation or respiration,tissue hypoxia occurs rapidly.(4)


Haldane remarked not only does the body machine breakdown,but the machinery is wrecked.(4)


In case circulatory arrest,the pupil dilate in 45 sec and respiratory stop within one minute due to medullry depression.(4)


In the adult the brain may be damaged within 4-6 minutes (2). If respiratory arrest occurs first the circulation continue for 5 minutes. A prompt decision to initiate effective resuscitative measure is required,since the greater the time lag between cardiac arrest and therapy,the lesser the likelihood that normal brain function will return. Hence the main objective of cardiopulmonary resuscitation is the effective delivery of oxygenated blood to the tissues.(4)


Failure to reinstitute artificially an adequate flow of oxygenated blood to the brain within 3 minutes of cardiac arrest dooms the patients to irreversible cerebral damage.(4)


DIAGNOSIS OF CARDIAC ARREST :


Absence of pulsation in mayor vessels such as a carotid or femoral or axillary artery or absence of the heart sound over the precordium.indicates loss of functional circulation.(4)


An ECG can easily detect asystole or ventricular fibrillation. Cardiac asystole there is absence of elctrical activity.The ECG tracings shows only a straight line.Ventricular fibrillation account for 75% of cardiac arrest ,especially after myocardial infarct. The ECG tracing shows wavy,irregular and chaotic activity.


Electro mechanical dissociation (EMG) or Pulseless electrical activity(PEA) regular electrical activity may be seen with a recognizable electro cardiographic complex but there is in adequate cardiac output,as evidence by absence of a palpable pulse,as in profound cardiovascular collapse where ECG appears normal in configuration but usually of low voltage.(2.4)


A systolic of about 50 mmHg is necessary for the pulse to be palpable.(4)


Agonal gasping respiration followed a respiratory apnoe is diagnosed by the chest movement or breath sounds.


Dilatated pupils that are unresponse to light are suggestive,but not necessary diagnostic of brain hypoxia.


Loss of conciousness and flaccidity,if the patient convulsies the brain not anoxic yet.(4)


The cessation of surgical bleeding and pallor of the skin.


CAUSATION  OF CARDIAC ARREST :


Sudden failure of cardiac action or output may be due to asystole or ventricular fibrillation.


Aetiological factors :(3)


I.Myocardial hypoxia :


1.This may be anoxic in origin due to a reduction of oxygen 
   concentrations in  the inspired atmosphere to : 
   - obstruction to the upper respiratory tract.
   - failure of adequate movement of the chest.
   - a diffusion block at alveolar level


2.As result from extreem hypotension and gross anemie with milder hypotension, or under ventilation.


3. Massive pulmonary embolus or air embolus produce inadequate coronary perfussion.


4.Certain poisons such as cyanide which inhibits cytochrome oxydase system and prevent cellular oxygenutilization.


II. Hypercapnia


Secondary to obesity or chronic lung disease


- Results in endogenous adrenaline release and hyperkalemia.


This more common occurence of cardiac arrest when the halothane as anesthetics.


III. Reflex stimuli :


Vagal stimulus such as occulocardiac reflex during traction on the extrinsix occular muscle.


IV. Overdosage of drugs or drug sensitivity :


- direct depression of the myocardium
- extreem hypotension
- hypoxia or hypercapnia following respiratory depression.


V. Changes of ionic environment :


- hyperkalemia in uremica or following massive transfusion or metabolic acidosis.


VI. Hypothermia : 


- Slow the heart rate and depresss conduction if cooling is continued of about 15 degree Celcius asystole is produced 
often preceded by ventricular fibrillation.


- The very rapid infusion of cold blood has been implicated in the causation of cardiac arrest.


VII. Mechanical stimulation


Incidental handling or retraction of the heart has resulted sudden ventricular fibrillation(VF).


VIII Electrical shock :
Death from electrocution from asystole or VF


IX. Intrinsix myocardial disease - coronary thrombosis.


INCIDENCE : (2)


Cardiac arrest more frequent :

1. In geriatric or pediatric
2. In patients with hystory of arrhythmia ,heart block myocard infarct (MI) or CHF.
3. In massive haemorrhage
4. During following heart surgery


PREVENTION :


The majority of studies that tend to promote cardiac arrest are preventable :(2)


A.Identification of high risk patient by careful attention to previous history of heart lung or kidney diseases, diabetes mellitus (DM),drug allergy or addiction and blood dyscrasia


B.Special attention should be given to following :


1. Maintainance of adequate volume.
2. Proper choice of preanesthetic medication.
3. Vagal stimulation by intubation or other maneuvers should be done during induction of anesthesia following hyperoxygenation.
4 .Blood loss during surgery must be check and replace properly.
5. Arterial blood gases,pH,and electrocytes must be monitored continously.
6. Respiratory insufficiency should be watched for and anticipated during recovery. Post operatively,respiration is frequently depressed and additional oxygen or assistance with a respirator may be necessary.


While a patient may be well ventilated during surgery,during recovery the patient may developed a progressive hypoxia and hypercapnia. Possibly leading an irritable myocardium into VF.


C.Avoid hazardous maneuvers :


Suctioning of the trachea in a hypoxic patient is often the stimulus for cardiac arrest.


D.Induction of anesthesia must always be done very carefully particularly in high risk patients with the following precautious :


1. Continuous ECG monitoring
2. Use of chest or oesophageal stethoscope
3. Availability of a DC defibrilator.
4. Ready availability of all drugs for therapy of cardiopulmonary arrest.




There are five steps in the prevention of biologic death from sudden cardiac standstill(4)


1. Rapidly recognize cradiac an respiratory arrest, singly or 
    combination.
2. Immediately institute artificial ventilation.
3. Quickly provide tecniques that arificially circulate blood.
4. Promptly administer appropriate drug therapy.
5. Apply post resuscitative care procedures designed to minimize the detererious effect of the arrest.


PROGNOSIS IN CARDIAC ARREST :(7)


Prognosis after cardiac arrest is influenced by time to initiate basic cardiopulnary resuscitation (CPR) and advance cardiac life support(ACLS).


In addition prognosis after CPR is influenced by the type of initial arrhythmia, Patients experiencing tachyarrhythmia (ventricular fibrillation(VF) or ventricular
tachycardia(VT), generally have a better prognosis than patients experiencing asystole or PEA unless the PEA results from mechanically correctable from obstructive shock such as a tension pneumothorax or pericardial tamponade.


Arrhythmic arrest may be prepicitated by electrolyte abnormalities in critically ill patients. Review of the most recent laboratory data should be conducted early during resuscitation. Cardio pulmonary arrest in infants and children is rarely a sudden event. More commonly it is secondary to progressive respiratory or circulatory failure that deteriorates to asystole or pulseless cardiac arrest.If respiratory failure or arrest is treated promptly the child is likely to survive intact.If respiratory arrest is allowed to progress to pulseless cardiac arrest, the outcome is poor.


Therefore early initiation of oxygenation and ventilation is the utmost importance.

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