1.What is the mechanism of mannitol to reduce intracranial pressure? A: After the intravenous injection of hypertonic solution (such as mannitol), the osmotic pressure of blood can rise rapidly, so that part of the water of brain tissue and cerebrospinal fluid can enter the blood, which dehydrates the brain tissue and reduces the intracranial pressure. Therefore, when infusing mannitol, it should be input quickly, generally 250 ml should be finished in 20-30 minutes. Oral can not play the above role, so can not be taken orally. 2, fast intravenous injection of magnesium sulfate will have what consequences, how to first aid? Answer: magnesium sulfate intravenous injection speed is too fast, the magnesium ion concentration in the blood can increase, inhibit the central nervous system and heart, and has blocked the motor nerve muscle and joints and other reactions, causing a drop in blood pressure, limb paralysis and respiratory paralysis. In the above cases, the drug should be immediately stopped, intravenous injection of 10% calcium gluconate or 5% calcium chloride injection to rescue. 3.What should I pay attention to when pushing aminophylline intravenously? A: Intravenous aminophylline must be injected after dilution, and strictly control the injection speed and dose, and children should be used with caution. Patients with myocardial infarction with reduced blood pressure should not be used. 4.What is the meaning of total intravenous nutrition? A; It is a method to inject hypertonic glucose, protein, electrolytes and vitamins from vena cava into the patient’s body. To make the calories, amino acids, electrolytes and vitamins to a more satisfactory degree, instead of the gastrointestinal tract to supplement nutrition, in order to maintain the tissue repair and the needs of the body growth. 5.What is CPR A,B,C ? A: The patient in cardiac and respiratory arrest to take a rapid and effective way to restore it, known as cardiopulmonary resuscitation. The so-called A, B, C is to determine the heartbeat, respiratory arrest, that is, according to the A, B, C sequence of resuscitation.” A” (Airway) refers to open the airway, the method is: head back, hold the neck, hold the jaw, so that the airway open; “B” (Breathing) refers to artificial respiration, the method is: mouth to mouth or mouth to nose will blow air into; “C” (Circula-tion) refers to artificial circulation, the method is: fist pounding the patient’s precordial area, that is, boxing pacing, etc.. 6.What are the clinical manifestations of cardiac arrest? A: The clinical manifestations of cardiac arrest are: 1) acute loss of consciousness and respiratory arrest after gasping; 2) disappearance of radial artery, femoral artery or carotid artery pulsation; 3) disappearance of heart sounds; 4) acute pallor or cyanosis; 5) spasmodic tonicity; 6) acute weak dilatation of pupils (starting 30 seconds after cardiac arrest); 7) electroencephalographic wave hypoplasia; 8) electrocardiographic changes. 7.What are the main points of clinical observation of patients in shock? A: Consciousness and expression, skin color, temperature, humidity, peripheral venous filling, blood pressure and pulse pressure difference, pulse rate, respiratory rate and depth, urine volume and urine specific gravity. 8.Why is there no urine in severe shock? A: Severe shock patients can occur in the microcirculatory dysfunction, causing extreme lack of tissue perfusion, which significantly reduces renal blood flow and causes renal ischemia, renin increases, causing further contraction of the renal vasculature, glomerular filtration is more reduced or even stopped, resulting in oliguria or anuria. At the same time, the parenchymal damage caused by shock also causes the aggravation of oliguria or anuria. 9.Why do we need to keep urine specimens in the early morning? A: Because the urine discharged in the early morning is more stable in terms of volume and content of various components, and it is not affected by food and has the lowest PH value. It is conducive to maintain the integrity of formed components such as cells and tubular forms.