【正文】 lts in cell death from oxygen starvation. ? Cerebral hypoxia, or lack of oxygen supply to the brain, causes victims to lose consciousness and stop breathing. ? Cardiac arrest is a medical emergency that, if left untreated, invariably leads to death within seconds to minutes. ? The primary firstaid treatment for cardiac arrest is cardiopulmonary resuscitation. 5 Etiology ? Coronary artery disease (CAD) is the predominant disease process associated with sudden cardiac death in the United States. ? In apparently healthy adults, cardiac arrest is often caused by ventricular fibrillation during myocardial infarction (heart attack). ? In children, cardiac arrest is typically caused by hypoxia from other causes such as neardrowning. With prompt treatment survival rates are high. ? Every fatal injury or illness ultimately terminates in cardiac arrest, which is a natural part of the processes of death. 6 Diagnosis ? The state of cardiac arrest is diagnosed in an unconscious (unresponsive to vigorous stimulation) person who does not have a pulse . ? An ECG clarifies the exact diagnosis and guides treatment. but treatment should begin without awaiting an ECG. 7 cardiac arrest four rhythms ? Ventricular fibrillation % ? Ventricular standstill (asystole) % ? Electromechanical dissociation(EMD) % ? Ventricular tachycardia % ? There are 4 rhythms which result in a cardiac arrest. VF and VT are both responsive to a defibrillator and so are colloquially referred to as shockable rhythms, whereas asystole and EMD are nonshockable. 8 Cardiopulmonary Resuscitation (CPR) Definition 是指對于早期心臟呼吸停止的病人，通過采取人工呼吸，人工循環(huán)，電除顫等方法幫助病人恢復(fù)自主心跳和自主呼吸的一種急救技術(shù)。 「 B」 =Breathing 人工通氣 。 ? If foreign body is lodged in the oropharynx, the Heimlich maneuver is performed. 18 BLSairway 19 Basic Life Support —breathing ? Proper check of the patient39。s chest and put your hands in the correct position again. ? Repeat this cycle of 30 and 2 for a total of 3 times every minute. 29 When to stop? ? Continue until there is: ? breathing, coughing or movement or other signs of circulation return ? qualified help arrives and you are asked to stop (if a defibrillator arrives, its operation will have priority on the CPR). ? you are too exhausted to continue. ? It is also important to note that, particularly in elderly patients, crepitations 劈拍聲 will often occur. Crepitations are the shattering碎裂 of bones in the rib cage and sternum. They can be both heard and felt. Do not discontinue CPR due to crepitations, although check your hand position if bone breakage appears to be excessive. 30 CPR 31 Effectiveness ? CPR is almost never effective if started more than 15 minutes after collapse because permanent brain damage has probably already occurred. A notable exception is cardiac arrest occurring with exposure to very cold temperatures. There are cases where CPR, defibrillation, and advanced warming techniques have revived hypothermia victims after over 30 minutes. ? In respiratory arrest, when the victim still has a heartbeat, such as in drowning, choking, or drug overdose with opioids or sedatives, the Airway and Breathing part of CPR is relatively very effective. About 10% of those on which CPR has been performed will recover entirely. 32 Complication of chest pression ? 1. Gastric distentiondue to breathing too forcefully and/or too quickly, causing air to enter the stomach. 2. broken ribs ? 3 Pneumothorax 4. Disease transmission, including herpes, HIV, Hepatitis, Mononucleosis, Influenza, Staph infection, and TBdue to inadequate or no protective mask. 5. Vomiting and possible aspiration into lungs. 33 Advanced Life Support,ALS and Arrhythmia Rocognition ? Attach a defibrillator–monitor ? Monitor the cardiac rhythm: ? Place the defibrillator paddles or selfadhesive electrode pads on the chest wall。 amiodarone。verapamil。furosemide。thrombolytic agents。 cardiac care。 SAPS – physiologically based classification systems ? General severity scores ? Aim at stratifying patients based on their severity ? 1985 – 1993: general oute prediction models ? 1991 – APACHE III ? 1993 – SAPS II ? 2022 – SAPS III ? 2022 – APACHE IV ? During process of evolution of models, main prognostic determinants of oute changed 67 APACHE ? William Knaus ? Initially 34 physiological variables ? 1985 – APACHE II 12 variables ? APACHE II allows probability of death before hospital discharge to be estimated ? Standardised mortality ratio 68 APACHE ? acute physiology and chronic health evaluation ? APACHEⅡ 0～ 71 ? APACHE Ⅲ 0～ 299 69 APACHE II score = (acute physiology score) + (age points) + (chronic health points) Scores range from 0 – 71 ? Score ? risk of hospital death 70 71 MPM (Mortality Prediction Models) ? Developed by Stanley Lemeshow ? Uses data collected during first hour of ICU admission。 administrative applications: assessing severity of illness Determining resource requirements Assessing use of critical care facilities