critical care medicine
Cardiac Arrest
Diagnosis of Cardiac Arrest
Clinical evaluation Cardiac monitoring and electrocardiography (ECG) Sometimes testing for cause (eg, echocardiography, chest imaging [x-ray, ultrasonography], electrolyte testing) Diagnosis of cardiac arrest is by clinical findings of apnea, pulselessness, and unconsciousness. Arterial pressure is not measurable. Pupils dilate and become unreactive to light after several minutes. A cardiac monitor should be applied; it may indicate Ventricular Fibrillation (VF) (VF), The patient is evaluated for potentially treatable causes; a useful memory aid is "Hs and Ts": H:Hypoxia,hypovolemia, acidosis (hydrogen ion),hyperkalemia orhypokalemia,hypothermia hrombosis ( Pulmonary Embolism (PE) or coronary) In pediatric cardiac arrest,hypoglycemia is another potentially treatable cause. Unfortunately, the cause of cardiac arrest often cannot be identified during cardiopulmonary resuscitation (CPR). Clinical examination, chest ultrasonography during CPR, and chest x-rays taken after return of spontaneous circulation following needle thoracostomy can detect pneumothorax, which suggests Diagnosis as the cause of the arrest. Cardiac ultrasonography can detect cardiac contractions and recognize Diagnosis , extreme hypovolemia (empty heart), right ventricular overload suggesting Rapid bedside blood tests can detect abnormal levels of potassium, helping to confirm suspicion that cardiac arrest was caused by an arrhythmia secondary to hyperkalemia. History given by family or rescue personnel may suggest overdose. 