Clinical Features, Complications And General Measures Of Treatment Of Shock
The Shock Syndrome
The Shock syndrome is characterised by rapid thready pulse, cold clammy skin and systolic blood pressure below 90 mmHg. Alteration in the consciousness such as agitation, somnolence, confusion or coma is a common feature. The urinary output falls below 20 ml/hour. With the urinary sodium falling below 30 meq/liter. Metabolic acidosis manifests with tachypnea and Kussmaul's respiration. Several complications develop if shock continues. The majority of cases end up fatally, if left untreated.
1. Pulmonary: Adult respiratory distress syndrome (ARDS), characterized by tachypnea, diffuse bilateral rales and respiratory failure.
2. Cardiac: Myocardial dysfunction and arrhythmias.
3. Renal: Acute tubular necrosis and obstruction of tubules by casts.
4. Gastrointestinal: Hepatocellular failure, mesenteric vasoconstriction, hemorrhagic necrosis of bowels.
5. Hematological: disseminated intravascular coagulation (DIC).
Treatment of Shock
General measures: Shock should be diagnosed early. Survival is inversely related to the duration of the shock before starting treatment. Prompt institution of specific treatment reduces mortality. The patient is put to bed with foot-end of the bed elevated to increase the venous return to the heart. Patency of the airway is established by removing foreign bodies from the mouth and throat and by keeping the neck extended backwards to prevent the tongue from falling back. If there is pain, morphine 5mg is given intravenously and repeated, if needed, every 10-15 minutes to reach a total dose of 15-20 mg. Vital signs like pulse, respiration, blood pressure and urine flow are monitored. A venous cannula introduced into the jugular vein helps monitoring the central venous pressure and also in administering fluids, if prolonged treatment becomes necessary. It is ideal to keep the ventral venous pressure at 10-14cm of water. metabolic acidosis is corrected by administration of 50-100 meq of sodium bicarbonate given as a 7.5% solution.
Vasopressor drugs: Sympathomimetic drugs are used to improve vascular tone. Dopamine is given intravenously at a rate of 3-15 ug/kg/min, depending upon the response of blood pressure and urine output. Other drugs in this group are isoprenaline (4-8 ug/min) and dobutamine (3-15 ug/Kg/min). These drugs cause improvement in cardiac output and blood pressure, but cardiac arrhythmias may be precipitated.
AED steps of CPR
Hypovolemic shock: Rapid replacement of the blood volume by administration of the appropriate fluid (depending on the fluid lost) is life-saving and this should be undertaken without delay. Blood, isotonic saline or plasma volume expanders such as 6% dextran or other colloidal solutions should be used. The rate of infusion should match the rate of fluid loss. In severe cases of gastro-enteritis up to 3-4 liters of fluid, may have to be infused in the first 1-2 hours. Fluid infusion is continued until the systolic blood pressure comes up to 100 mmhg. Further maintenance depends on rate of fluid loss. If the shock is unresponsive to replacement of conventional fluids, infusion of 7.5% saline (100-400ml) may help to restore the blood pressure.
Cardiogenic shock: Inotropic agents to improve cardiac contractility, vasodilators to reduce the afterload on the heart and correction of the cardiac abnormality are the main principles of treatment. If the cardiac output is persistently low, the circulation can be assisted by means of balloon counterpulsation in the aorta if facilities permit. The balloon is position in the upper part of descending aorta. It is inflated during diastole and deflated during systole. This helps in reducing afterload in systole and increase the diastolic filling pressure of the ventricle. By these mechanisms, balloon counterpulsation improves the cardiac output and coronary circulation. In conditions such as rupture of interventricular septum or acute damage to a valve, emergency surgery may have to be undertaken if the shock remains unresponsive to medical treatment.
Anaphylactic shock: It is treated by intramuscular injection of 1ml of1/1000 adrenaline, repeated if needed every 5-10 minutes. Adrenaline corrects the hypotension and bronchospasms. If the bronchospasm is severe, 250mg of aminophylline is given intravenously slowly. In severe cases, hydrocortisone in doses of 100mg or its analogues (betamethasone or dexamethasone 8mg) are given intravenously either by repeated injections or through an intravenous drip, until the condition improves. If laryngeal edema obstructs the airways, emergency tracheostomy has to be done to save life.
© 2013 Funom Theophilus Makama