③ Correction of the underlying disease state, while supporting and protecting all organs and assisting them in recovery to as near prearrest state as possible. ② Restoration of spontaneous cardiac and respiratory activity and establishment of circulatory self-sufficiency ① Basic life support, providing temporary perfusion of vital tissues.
There were no immediately applicable effective emergency resuscitation techniques available before 1950s.
Modern respiratory resuscitation was pioneered in 1950s
safar: opening airway 1958,
Elam: mouth to mouth breath,),
Modern circulatory resuscitation in the 1960s Kouwenhoven :external cardiac compression,1960 ,
Therapeuticall promising reseach on brain resuscitation began in 1970.
4. Anatomy and function of the circulatory system
The circulatory system is similar to a city water system:
The heart functions as a pump
The blood vessels as a network pipes
The blood as fluid
4. Anatomy and function of the circulatory system
After blood picks up oxygen in the lungs ,it goes to the heart ,which pumps the oxygenated blood to rest of the body.
The cells of the body absorb oxygen and nutrients from the blood and produce waste products(including carbon dioxide),that blood carries back to the lungs.In lungs ,the blood exchanges the carbon dioxide for more oxygen .Then the oxygenated blood returns to the heart to be pumped out again.
If the heart stop contracting,and no blood is pumped through the blood vessels.Without a supply of blood, the cells of the body will die because they cannot get any oxygen and nutrients and they cannot eliminate waste products.
Clinical Death has been defined by Negovsky as “the period of respiratory,circulatory,and brain arrest during which initiation of resuscitation can lead to recovery with prearrest central nervous system function.” Clinical Death is a reversible state
The duration of clinical death depends on the length of time of the cerebral cortex survives in the absence of circulation and respiration.
Under normal temperature ,from clinical death to biologic death ,the period does not exceed 3-6min.
Sudden cardiac death (also called sudden arrest) is death resulting from an abrupt loss of heart function (cardiac arrest). The victim may or may not have diagnosed heart disease. The time and mode of death are unexpected . It occurs within minutes to 1 hour after symptoms appear. The most common cause of cardiac arrest is coronary heart disease.
Sudden cardiac death is the clinical death,This is a reversible condition.In most victims if it's treated within a few minutes with an electric shock to the heart to restore a normal heartbeat. This process is called defibrillation.
Causes of cardiac arrest cardiac extracardiac Primary lesion of cardiac muscle leading to the progressive decline of contractility, conductivity disorders, mechanical factors all cases accompanied with hypoxia Death concepts
Resuscitation success is dependent on each link in the chain. Early defibrillation has emerged as a single element of ALS that appears to have the greatest impact on ultimate survival.When defibrillation alone is added to the BLS regimen,survival increases from 6% to 25% for prehospital VF.
A victim's chances of survival are reduced by 7 to 10 percent with every minute that passes without defibrillation.
Sudden death is unique.Time constraints are extreme. If resuscitative interventions are not begun within 5-7min,there is little likelihood of sucessful resuscitation and functional survival.Few attempts at resuscitation succeed after 10 minutes.
Most survivors of cardiac arrest are from the group of patients . . .
Whose collapse is witnessed by a bystander,
Who receive cardiopulmonary resuscitation (CPR) within 4 to 5 minutes, and
Who receive advanced cardiac life support (ACLS), e.g., defibrillation, intubation, drug therapy, within the first 10 minutes.
Decapition the head is separated from the rest of body.When this occurs,there no chance of saving the patient.
Rigor morits This is the temporary stiffening of muscles that occurs several hours after death. The presence of this stiffening indicate the patient dead and cannot be resuscitated .
Evidence of tissue decompositon Tissure decomposition or actual flesh decay occurs after a person has been dead for more than a day.
Dependent livdity It is the red or purple color that appears on the parts of the patien’s body that are closest to the ground.It is caused by blood seeping into the tissure on the dependent,or lower, part of the persion’s body. It occurs after a persion has been dead for several hours
Adult Basic Life Support Check responsiveness Call for help Correctly place and open airway Check breathing breathe Assess 10 second only Pulse present Continue rescue breathing No pulse Compress chest Shake and shout Head tilt/chin lift Look,listen and feel 2 effective breatha Signs of a circulation 100per minute 30:2 BLS
Positioning the patient supine on a flat, firm surface with arms along the sides of the body, Always be aware of head and spinal cord injuries stabilize the cervical spine by maintaining the head ,neck, and trunk in a straight line
2.A – airway control BLS Part Ⅱ Ensure open airway by preventing the falling back of tongue, tracheal intubation if possible
Head-tilt/chin-lift is usually the first maneuver , if no concern cervical spine injury . This is done by placing one hand on the forehead ,and placing the tips of fingers of other hand under the bony part of the chin.life the chin foreward,bring the entire lower jaw with it ,helping to tilt the head back.
This is the safest method for opening the airway if there is the possibility of cervical spine injury.this is done by playing placing the fingers behind the angle of the jaw and bring the head foreward.
listening for sounds of breathing, placing your ear over the patient’s nose and mouth
feel and hear the movement of air If no spontaneous breathing ,you must begin artifical ventilation immediately.
mouth to mouth or mouth to nose respiration ventilation by a face mask and a self-inflating bag with oxygen 2 initial subsequent breaths wait for the end of expiration 10-12 breaths per minute with a volume of app. 800 ml, each breath should take 1,5-2 seconds Algorithm for artificial ventilation Control over the ventilation check chest movements during ventilation check the air return
Both mouth to mouth and mouth to nose ventilation can provide large volumes ， the concentration of oxygen delivered to the patient is 16%~17% ， may produce an alveolar partial pressure of oxygen of 80mmHg,more than enough to patient’s life.
● With mouth to mask ventilation connected to high flow oxygen ， the concentration of oxygen is 55% 。
4.C -Circulation BLS Part Ⅱ Restore the circulation, that is start external cardiac compression-ECC
● After 30 chest compressions give:2 slow breaths ( Ratio of compression-to-ventilations 30:2)
Continue until help arrives or victim recovers
If the victim starts moving: check breathing
Part Ⅱ BLS
mechanisms explaining the restoration of circulation by external cardiac massage Cardiac pump Thoracic pump
Cardiac pump during the cardiac massage Blood pumping is assured by the compression of heart between sternum and spine Between compressions thoracic cage is expanding and heart is filled with blood
1 ． Oropharyngeal airway has two major purpose.The first is to keep the tongue from blocking the upper airway.The second is to make suctioning the airway.This should be inserted in unconscious patients, and is often used inconunction with BVM ventilation
2 ． Nasopharyngeal airway
often used for a conscious patient who is not able to maintain an airway.This airway is usually well tolerated and is not a likely a the oropharygeal airway to cause vomiting.
Is the definitive technique for airway management in ALS. It should be performed as soon as possible in all patients for whom CPR .especially in the patient who cannot be rapidly resuscitated .It is a mandatory skill for any physician who cares for critically ill patients.
Note :The resuscitative efforts should not be interrupted by more than 30s with each attempt.
Chest compression during ALS are performed in the same manner as in BLS.
Newer techniques include the use of compression-decompression devices and abdominal counterpulsation compression-decompression device. These mechanical devices were used,have result in improved rates of return of spontaneous circulation but not in improved ultimate survial.
Defibrillation is the defnitive treatment for the vast majority of cardiac arrests.It should be delivered as early as posible.
At least 50% of patient in cardiac arrest are in VF when the first ECG.
In early 1970s “blind”defibrillation was recommended as soon as a defibrillator was available.
However, current defibrillators with quick-look paddles enable visualization of the rhythm disturbance upon arrival the defibrillator.As soon as ventricular fibrillation is documented,defibrillation as described below should be perform.
Precordial thump If an electrical defibrillator is not immediately available,a precordial thump should be employed.A sharp blow with the outside of a fist is delivered to the sternum from height of 8-12in (25 ～ 30cm).
If this successfully results in sinus rhythm, a bolus of lidocaine should be given.If VF persists, proceed to BLS and to defibrillation as soon as the defibrillator is available.
● Electrical defibrillation: passing an electrical current through a fibrillating heart, and causing synchronous depolarization the disorganized contracting myofibrils at once ,and allowing for uniform repolarization and subsequent organized cardiac electromechanical activity.
AED with a large pads.This machine can recognize VF and deliver direct current(DC) countershock with better than 85% sensivity and with 100%specificity.Defibrillation success rate appears equal traditional handheld defibrillator. The potential impact of using this technology widely in public setting such as office building,stadiums( 体育场） ,factorices airport railway stations,and rural areas served by volunteer rescue personnel.
⑸ Adequate contact (Apply electrode gel or saline-soaked4×4 gauze pads) between paddles and skin
⑹ Proper position of the paddles
Antero-apical position: one paddle is placed to the right of the sternum just below the clavicle.another paddle is placed to the normal cardiac apex . Antero-posterior position : the anterior paddle placed over the apex,and the posterior paddle on the back in the left or right infrascapular （ 肩胛下的 ） region. Proper position of the paddles There two widely accepted positions for the paddles that optimize current delivery to the heart:
ALS Part Ⅱ ⑺ Clear the area ,no contact with anyone other than the victim. ⑻ Recheck the ECG ⑼ Activate the firing button. ⑽ If no skeletal muscle twitch or spasm has occurred ， you should check the equipment ， contacts ， and synchronizer switch Procedure of Electrical defibrillation ⑾ The rhythm should be assessed after each countershock and the patient should be checked for a pulse at appropriate time. ⑿ If unsuccessful,,repeat steps 4~11.
Possible arrhythmias after cardiac defibrillation
bradyarrythmia including electromechanical dissociation and asystole
supraventricular arrhythmia accompanied with tachycardia
supraventricular arrhythmia with normal blood pressure and pulse rate
If several shocks fail to stop VF , optimal chest compression,oxygen and intermittent positive-pressure ventilation, epineprine, lidocaine, and sodium bicarbonate should be given in this sequence. If this measure is unsuccessful, bretylium is indicated.Patients have occasionllay recovered after more than 1 hour of external CPR with multiple defibrillation attempts
ALS Part Ⅱ
5. Venous access ALS Part Ⅱ To establish a reliable intravenous route is an essential part of ALS ， this allow administration of necessary drugs and fluids during the CPR .
● Peripherial veins :usually recommed median cubital vein( 肘静脉） ， particularly during the arrest situation when access to the neck and chest is restricted by BLS procedure. when these route are being used,IV medication should be administered rapidly by bolus injection and following by a 20ml fluid bolus injection and elevate the extremity.
● Central venous offers more secure route for drug administration ， internal jugular or subclavian are preferable because of proximity to the heart ， but their placement should not be allowed delay defibrillation attempts or interfere with BLS. femoral vein cannulation is difficult to achieve during CPR.
★ Endotracheal route requires a higher dose to achieving an equivalent blood level .It is suggested that 2.5 times the IV dose be administered.Delivery of the drug to the circulation is facilitated by diluting the drug to a 10ml volume ,delivering it though a catheter positioned to the tip of the endotracheal tube.
To maintain the IV access and increased central volume are often required during CPR.The standard fluid infusion for ALS should be normal saline or lactated Ringer’s solution , rather than dextrose in water ,because glucose may exacerbate anoxic injury to the brain.
During CPR ,only a few drugs have proved useful.I introduce epinephrine, Vasopresine, Amiodarone lidocaine , atropine , magneium ,and sodium bicarbonate.
Part Ⅱ ALS
① Epinephrine ALS Part Ⅱ . Actions: Epinephrine can stimulate peripheral α-adrenergic receptor and cardial β adrenergic receptor ， increases resistance in non-cerebral and non-coronary arteries,result in decreased blood flow to non-cerebral and non coronary vessels.in creased aortic blood pressure and increased perfusion of heart and brain vessel .
It can help convert fine VF into coarse VF ， which is more susceptible to stop by electrical shock .
Indication : include all forms cardiac arrest. It is recommeded in VF/VT cardiac arrest if there is no ROSC(return of spontaneous circulation) after first three defibrillation.It is recommended in EMD and asystole after initiation of CPR
Actions: Lidocaine is a class IB agent that depresses myocardial excitability by blocking sodium channels without extending action potential duration.
Indication : The drug is indicated in Ventricular ectopy, ventricular tachycardia and ventricular fibrillation that has recurred after a successful defibrillation or that has been refractory to defibrillation. Prophylactic lidocaine therapeutic dose is deemphasized.
Dose : The recommened dose is 1.5mg/kg bolus repeated in 5~10 min for total dose of 3mg/kg .
Actions: Amiodarone is classIII agent that has some classI activity weak non-competitive β-blocking effects.It lowers the defibrillation threshold and has potent antifibrillatory effect.its broad spectrum of antidysrhythmic effects make it a potentially useful agent.
Indication and dose: can be considered if multiple electrial shocks and epinephrine have failed to revert VF/VT.The initial dose is 5mg/kg given as a slow intravenous infusion over 5-15min.This may be repeated if indicated
Class I recommendation (definitely helpful) : symptomatic sinus bradycardia
Class II recommendation (acceptable, or possibly helpful) : atrioventricular block （ AVB ） at the nodal level, or in asystole.
Class III recommendation (not indicated, maybe harmful) : In Mobitz AVB or CHB.
Actions: Magnesiun is an essential electrolyte that may be depleted by duretics,severe diarrhoae and alcohol abuse.Hypomagnesaemia may cause cardiac dysrhythmias . Indication ： Magnesium may be considered in refractory VF/VT,particularly hypokalaemia is present,and is an agent of choice in torsaded de pointes. Dose: The initial dose is 5mmol given over1 minute, which may be repeated if indicated and followed by an infusion of 20 mmol over 4 hours . ⑤ Magnesium Sulfate
There two components contributing to the acid load.
Respiratory acidosis :result from failure carbon dioxide eliminition, carbon dioxide(CO 2 ) production continues , but it can not be remove because pulmonary and heart failure during CPR, the PaCO 2 rise.
Metabolic acidosis: develops prolonged tissue hypoperfusion and conversion to anaerobic forms of metabolism.
Actions: Sodium bicarbonate (NaHCO 3 )is an alkalinizing agent,that theoretically reverse the metabolic acidosis associated with profound ischemia.However,provided CPR is effective, acidosis does not develop rapidly or severely in otherwise healthy individuals during during cardiac arrest.
Indication and dose:It is unneccessary in brief resuscitation when the patient have been previously well.It can be considered if cardiac arrest exceeds 10-15mintures duration.It should be considered when cardiac arrest occurs in a patient with a prexisting profound acidosis or in special conditions,such as hyperkalaemia and tricyclie antidepressant overdose .
Note: If alveolar ventilation is not adquate,the CO 2 released from the NaHCO 3, ,and correction of the acidosis will not be attained, and may result inincreased central venous and tissue PaCO 2 level .Tissue acidosis may worsen following NaHCO 3, administration.
These complications are more likely to occur when ventilation pressure exceeded the opening pressure of the lower esophageal sphincter .In mouth-to-mouthe ventilation,1.5~2.0seconds shouled be allowed for air delivery to the lungss to prevent airway pressure from exceeding 20~25cmH 2 O.Breathing rapidly without allowing full exhalation should be avoided for same reason.
● Complication of defibrillaton Skin burns (common) Skeletal muscle injury or thoracic vertebral fractures (uncommon) Myocadial injury and post-defibrillation dysrhythmias (high-energy shocks) The rescuer can receve electrical injures(due to electrical contact with the patients during defbrillation The complication of CPR
ECG monitoring is essential during resuscitation, both as a diagnostic tool and as a guide to the most effective therapy.Initially,the “quick look” paddles should be used.if available,the standard ECG machine or monitoring unit with a display screen should be attached as soon as possible.
Blood pressue Intra- arterial pressure monitoring provides an accurate and continuous measure of SBP 、 DBP and MAP.Continous intra-arterial monitoring during CPR allows for rational titration of vasoconstrictor therapy and accurate assessment of the hemodynamic effectiveness of spontaneous rhythms 。
Endotracheal CO 2 monitoring provide a noninvasive measure of pulmonary perfusion (CO).Which also has been shown to correlate with coronary perfusion pressure.Patients who have undergoing 10~15 min of ECC with accompanying ALS ,and have an endotracheal CO2 above 10-15mmHg are unlikely to survive.
Laboratory investigation will guide ongoing therapy.The most useful initial measurements include arterial blood gas,the hematocrit,serum glucose, sodium, potassium, calcium.if abnormalities are noted,they may be treated, and the succes of such treatment maybe monitored by repeated measurement.