Angiotensin-converting-enzyme inhibitors are a class of medication used primarily for the treatment of high blood pressure and heart failure. This class of medicine works by causing relaxation of blood vessels as well as a decrease in blood volume, which leads to lower blood pressure and decreased oxygen demand from the heart.
Shock is the state of insufficient blood flow to the tissues of the body as a result of problems with the circulatory system. Initial symptoms of shock may include weakness, fast heart rate, fast breathing, sweating, anxiety, and increased thirst. This may be followed by confusion, unconsciousness, or cardiac arrest, as complications worsen.
Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs.
Human vasopressin, also called antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin, is a hormone synthesized from the AVP gene as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP. It then travels down the axon terminating in the posterior pituitary, and is released from vesicles into the circulation in response to extracellular fluid hypertonicity (hyperosmolality). AVP has two primary functions. First, it increases the amount of solute-free water reabsorbed back into the circulation from the filtrate in the kidney tubules of the nephrons. Second, AVP constricts arterioles, which increases peripheral vascular resistance and raises arterial blood pressure.
Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in controlling hemorrhage and reducing acute blood loss. When blood vessels constrict, the flow of blood is restricted or decreased, thus retaining body heat or increasing vascular resistance. This makes the skin turn paler because less blood reaches the surface, reducing the radiation of heat. On a larger level, vasoconstriction is one mechanism by which the body regulates and maintains mean arterial pressure.
Septic shock is a potentially fatal medical condition that occurs when sepsis, which is organ injury or damage in response to infection, leads to dangerously low blood pressure and abnormalities in cellular metabolism. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) defines septic shock as a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone. Patients with septic shock can be clinically identified by requiring a vasopressor to maintain a mean arterial pressure of 65 mm Hg or greater and having serum lactate level greater than 2 mmol/L (>18 mg/dL) in the absence of hypovolemia. This combination is associated with hospital mortality rates greater than 40%.
An inotrope or inotropic is a drug or any substance that alters the force or energy of muscular contractions. Negatively inotropic agents weaken the force of muscular contractions. Positively inotropic agents increase the strength of muscular contraction.
Atenolol is a beta blocker medication primarily used to treat high blood pressure and heart-associated chest pain. Atenolol, however, does not seem to improve mortality in those with high blood pressure. Other uses include the prevention of migraines and treatment of certain irregular heart beats. It is taken orally or by intravenous injection. It can also be used with other blood pressure medications.
Angiotensin II receptor blockers (ARBs), formally angiotensin II receptor type 1 (AT1) antagonists, also known as angiotensin receptor blockers, angiotensin II receptor antagonists, or AT1 receptor antagonists, are a group of pharmaceuticals that bind to and inhibit the angiotensin II receptor type 1 (AT1) and thereby block the arteriolar contraction and sodium retention effects of renin–angiotensin system.
Nadolol, sold under the brand name Corgard among others, is a medication used to treat high blood pressure, heart pain, atrial fibrillation, and some inherited arrhythmic syndromes. It has also been used to prevent migraine headaches and complications of cirrhosis. It is taken orally.
Phenylephrine is a medication used as a decongestant for uncomplicated nasal congestion, used to dilate the pupil, used to increase blood pressure, and used to relieve hemorrhoids. It can be taken by mouth, as a nasal spray, given by injection into a vein or muscle, or applied to the skin.
Telmisartan, sold under the brand name Micardis among others, is a medication used to treat high blood pressure, heart failure, and diabetic kidney disease. It is a reasonable initial treatment for high blood pressure. It is taken by mouth. Versions are available as the combination telmisartan/hydrochlorothiazide, telmisartan/cilnidipine and telmisartan/amlodipine.
Losartan, sold under the brand name Cozaar among others, is a medication used to treat high blood pressure (hypertension). It is in the angiotensin receptor blocker (ARB) family of medication, and is considered protective of the kidneys. Besides hypertension, it is also used in diabetic kidney disease, heart failure, and left ventricular enlargement. It comes as a tablet that is taken by mouth. It may be used alone or in addition to other blood pressure medication. Up to six weeks may be required for the full effects to occur.
Valsartan, sold under the brand name Diovan among others, is a medication used to treat high blood pressure, heart failure, and diabetic kidney disease. It belongs to a class of medications referred to as angiotensin II receptor blockers (ARBs). It is a reasonable initial treatment for high blood pressure. It is taken by mouth. Versions are available as the combination valsartan/hydrochlorothiazide, valsartan/amlodipine, valsartan/amlodipine/hydrochlorothiazide, or valsartan/sacubitril.
Distributive shock is a medical condition in which abnormal distribution of blood flow in the smallest blood vessels results in inadequate supply of blood to the body's tissues and organs. It is one of four categories of shock, a condition where there is not enough oxygen-carrying blood to meet the metabolic needs of the cells which make up the body's tissues and organs. Distributive shock is different from the other three categories of shock in that it occurs even though the output of the heart is at or above a normal level. The most common cause is sepsis leading to a type of distributive shock called septic shock, a condition that can be fatal.
Fenoldopam mesylate (Corlopam) is a drug and synthetic benzazepine derivative which acts as a selective D1 receptor partial agonist. Fenoldopam is used as an antihypertensive agent. It was approved by the Food and Drug Administration (FDA) in September 1997.
Dopexamine is a synthetic analogue of dopamine that is administered intravenously in hospitals to reduce exacerbations of heart failure and to treat heart failure following cardiac surgery. It is not used often, as more established drugs like epinephrine, dopamine, dobutamine, norepinephrine, and levosimendan work as well. It works by stimulating beta-2 adrenergic receptors and peripheral dopamine receptor D1 and dopamine receptor D2. It also inhibits the neuronal re-uptake of norepinephrine.
Norepinephrine, also known as noradrenaline, is a medication used to treat people with very low blood pressure. It is the typical medication used in sepsis if low blood pressure does not improve following intravenous fluids. It is the same molecule as the hormone and neurotransmitter norepinephrine. It is given by slow injection into a vein.
Vasopressin infusions are in use for septic shock patients not responding to fluid resuscitation or infusions of catecholamines to increase the blood pressure while sparing the use of catecholamines. These argipressins have much shorter elimination half-life than synthetic non-arginine vasopresines with much longer elimination half-life of many hours. Further, argipressins act on V1a, V1b, and V2 receptors which consequently lead to higher eGFR and lower vascular resistance in the lungs. A number of injectable arginine vasopressins are in clinical use in the United States and the European Union. Pitressin among others, is a medication most commonly used in the treatment of frequent urination, increased thirst, and dehydration such as that resulting from diabetes insipidus, which causes increased and diluted urine. It is used to treat abdominal distension following some surgeries, and in stomach roentgenography. Vasopressin is a hormone that affects the kidneys and reduces urine flow.
Vasodilatory shock, vasogenic shock, or vasoplegic shock is a medical emergency belonging to shock along with cardiogenic shock, septic shock, allergen-induced shock and hypovolemic shock. When the blood vessels suddenly relax, it results in vasodilation. In vasodilatory shock, the blood vessels are too relaxed leading to extreme vasodilation and blood pressure drops and blood flow becomes very low. Without enough blood pressure, blood and oxygen will not be pushed to reach the body's organs. If vasodilatory shock lasts more than a few minutes, the lack of oxygen starts to damage the body's organs. Vasodilatory shock like other types of shock should be treated quickly, otherwise it can cause permanent organ damage or death as a result of multiple organ dysfunction.
