The 4 H’s Hypoxia Hyper-/Hypokalemia Hypovolemia Hypothermia Hypoglycemia - Deprivation of adequate oxygen supply - High and Low potassium causes cardiac arrest - - If exposed to the cold, warming measures should be taken - Low serum blood glucose - Ensure patient’s airway is open - Major signs of hyperkalemia are taller, peaked T-waves and wide QRS complex on ECG - - Hypothermic patient may be unresponsive to drug therapy and electrical therapy (defibrillation or pacing). Treat hypoglycemia with IV dextrose to reverse a low blood glucose. - Removed from 4 H’s but still important measurement. - - Ensure chest rise and fall and bilateral breath sounds with ventilation present. - Ensure 100% oxygen supply is connected properly and patients lungs are ventilated adequately. Interventions for hyper = sodium bicarbonate (IV), glucose and insulin, calcium chloride (IV), Kayexalate, dialysis, and possibly albuterol. - - Major signs of hypokalemia are flattened T-waves, prominent U-waves, and widened QRS complex - Interventions for hypo = rapid but controlled infusion of potassium. NEVER give undiluted intravenous potassium - Loss of fluid volume in the circulatory system i.e. hemorrhage. Can be due to trauma, GI bleed or rupture of aortic aneurysm, sweating, severe diarrhea and/or vomiting, and even severe vasodilation. Severe burns. - Raise core temperature above 86 F (30 C) as soon as possible. - *USE LOW READING THERMOMETER Look for obvious blood loss in the patient with pulseless arrest Interventions = Obtain IV access and administer IV fluids (0.9% NaCl / Hartman’s/ blood transfusion) + URGENT control of bleeding (surgery, compression, interventional radiology, tourniquet). Fluid challenge or fluid bolus may to determine if the arrest is related to hypovolemia. The 4 T’s Tension Pneumothorax Cardiac Tamponade Toxicity Thrombosis (Heart: MI) Thrombosis (lungs: PE) Trauma - - - Accidental overdose: most common drugs are tricyclics, digoxin, beta-blockers, and calcium channel blockers. - - Blockage of the main artery of the lung which can rapidly lead to respiratory collapse and sudden death. - - Cocaine: most common and increases the incidence of pulseless arrest - ECG: narrow QRS Complex and rapid heart rate. Can be a cause of pulseless arrest. Requires good evaluation of the patient’s physical condition and history to reveal any traumatic injuries. - Physical signs: no pulse felt with CPR. distended neck veins, positive ddimer test, prior positive test for DVT or PE. - Treat each traumatic injury as needed to correct any reversible cause or contributing factor to the pulseless arrest. - Removed from the 4 T’s - - Air enters the pleural space and is prevented from escaping leading to a build-up of tension that causes shifts in the intrathoracic structure that can rapidly lead to cardiovascular collapse and death. ECG: narrow QRS complexes and rapid heart rate - Physical signs: Decreased air entry, decreased expansion and hyperresonance to percuss on affected side. Tracheal deviation, difficulty with ventilation, and no pulse felt with CPR - - Interventions = needle decompression. Emergency condition in which fluid accumulates in the pericardium (sac in which the heart is enclosed). Results in the ineffective pumping of the blood leading to cardiac arrest ECG: narrow QRS complex and rapid heart rate. Physical signs: JVP distention, no pulse or difficulty palpating a pulse, and muffled heart sounds due to the fluid inside the pericardium. Intervention = pericardiocentesis. - - - Physical signs: bradycardia, pupil symptoms, and other neurological changes ECG: prolongation of the QT interval Poison control can be utilized to obtain information about toxins and reversing agents. - Coronary thrombosis: an occlusion or blockage of blood flow within a coronary artery caused by blood clot. Causes an acute MI which destroys heart muscle and can lead to sudden death depends on the location of the blockage. ECG: ST segment changes, T-wave inversions and/or Q wave. - Physical signs: Chest pain and elevated cardiac markers i.e. trop levels - Interventions = fibrinolytic therapy, or PCI (percutaneous coronary intervention) - - Common PCI: coronary angioplasty with or without stent placement Interventions = surgical (pulmonary thrombectomy) and fibrinolytic therapy. Cardiac arrest due to PE = give thrombolytic drug immediately.
