Category: Critical Care Nursing
Right ventricular dysfunction results in a loss of blood flow through the lungs and a backup of blood into the venous system, causing symptoms such as venous engorgement. Any organ can be affected during this process.
Category: Critical Care Nursing
Left ventricular dysfunction results in failure to move blood to the tissues adequately. This threatens every organ's ability to maintain its normal metabolic activity. All tissues are at risk when left ventricular function is disturbed.
Category: Critical Care Nursing
Nitroprusside use has two disadvantages. First, it breaks down into cyanide. Second, it acts as a nonselective arterial dilator. This can result in an ischemic myocardium and is called the "coronary steal" phenomenon.
Category: Critical Care Nursing
The use of afterload reducers is common in two situations: during hypertensive episodes and when the cardiac output is low and the SVR is high. The principles of their use are similar in both situations.
Category: Critical Care Nursing
Preload reduction occurs with vasodilation. Drugs such as nitroglycerin, diltiazem and morphine reduce preload through vasodilation. Vasodilation causes an "internal phlebotomy" by reducing the amount of blood returning to the heart.
Category: Critical Care Nursing
In patients presenting with symptoms of left ventricle heart dysfunction, relief is obtained by improving the strength of the heart. This is also referred to as inotropic therapy, which increases the strength of the cardiac contraction.
Category: Critical Care Nursing
Cardiac catheterization involves the insertion of catheters into cardiac chambers and blood vessels to measure intracardiac pressures, oxygen saturation and coronary blood flow. Cardiac catheterizations can be left or right sided.
Category: Critical Care Nursing
Mechanical ventilation is indicated to improve or support alveolar ventilation, to reduce the work of breathing or to aid in supporting oxygenation. All mechanical ventilation modes are designed to support one of these three functions.
Category: Critical Care Nursing
Endotracheal tube position can change with coughing, patient movement and suctioning. Reassessment of endotracheal tube placement is essential and daily chest x-rays can help assess the tip position of the endotracheal tube.
Category: Critical Care Nursing
Some clinicians believe in physiologic PEEP, a concept assuming that some PEEP is present in all people due to resistance of the airways. Low levels of PEEP (3-5cm H2O) may be ordered for patients without oxygenation problems.
Category: Critical Care Nursing
Optimal PEEP levels are achieved by the lowest level of PEEP needed to raise the PaO2/SaO2 levels and do not result in cardiovascular compromise, such as decreased cardiac output, tachycardia or impeded right heart filling.
Category: Critical Care Nursing
Auto-PEEP, also known as intrinsic PEEP, is the trapping of air in the alveoli, producing PEEP as the result of early airway closure or insufficient exhalation time. Auto-PEEP may develop due to overly aggressive ambu-bagging.
Category: Critical Care Nursing
Pulmonary contusion is damage to the lung parenchyma, resulting in localized edema and hemorrhage. The thorax hits an object, such as a steering wheel, compressing the thoracic cage, diminishing its size and compressing the lungs.
Category: Critical Care Nursing
Milking and stripping of chest tubes is not recommended, as it has been shown to create suction pressures of up to -400cm H2O. This can cause damage to lung tissue, disruption of suture lines and does little to maintain chest tube patency.
Category:Critical Care Nursing
If a chest tube is inserted to remove air, it is inserted into the second or third intercostal space at the midclavicular line. The chest tube is sutured in place and connected to a water seal or suction drainage system.
Category: Fundamentals
A premature atrial complex (PAC) occurs as the result of an irritable focus in the atria that fires prematurely and produces a single ectopic beat. PACs are common among healthy people and may be triggered for a variety of reasons.
Category: Fundamentals
A sinus arrest, sometimes called a sinus pause, occurs when the SA node fails to discharge an impulse, creating a pause in the rhythm before it randomly resumes. During a sinus arrest, there is no electrical activity at all.
Category: Fundamentals
The P wave is the first component of a normal EKG waveform. P waves represent atrial depolarization, when the stimulated atria contract and push the blood through the open tricuspid and mitral valves into the relaxed ventricles.
Category: Fundamentals
The Purkinje Network is comprised of small conduction fibers that deliver electrical impulses to the ventricular muscle cells and like the AV node, can also function as a pacemaker with a firing rate of 20 to 40 beats per minute.
Category: Fundamentals
The sinoatrial node (abbreviated SA node) is positioned in the upper posterior section of the right atrial wall. In a normal heart, the SA node depolarizes faster than any other component, firing at a rate of 60 to 100 beats per minute.
Category: Fundamentals
The atrioventricular node (abbreviated AV node) is a group of cells located in the posterior septal wall of the right atrium. The AV node is the one and only tract to conduct electrical impulses from the atrium to the ventricles.
Category: Fundamentals
The heart has two types of cells: pacer cells and myocardial cells. The pacer cells are responsible for the spontaneous generation and conduction of electrical impulses. Myocardial cells are muscle cells or the "working cells."
Category: Fundamentals
The autonomic nervous system controls the heart rate. Actually, it manages all involuntary actions. It is divided into two main parts: the parasympathetic nervous system (cholinergic) and the sympathetic (adrenergic) nervous system.
Category: Fundamentals
Cardiac output is the volume of blood the heart pumps per minute. Normal cardiac output for an adult is between 4L-8L/minute. Cardiac output may be affected by hormone levels, body size, age and metabolic need.
Category: Fundamentals
The left anterior descending (LAD) is the most critical branch of the left coronary artery (LCA). It supplies the anterior wall of the right ventricle, the interventricular septum, the apex and the anterolateral wall of the left ventricle.
Category: Fundamentals
The coronary arteries supply the heart muscle with blood and oxygen. We identify coronary arteries by their location. When coronary arteries "end," they interconnect with other coronary branches, forming a collateral circulation system.
Category: Fundamentals
The atrioventricular valves are the tricuspid valve (right side of heart) and the mitral valve (left side of heart). These valves open to let deoxygenated blood into the right ventricle and oxygenated blood into the left ventricle.
Category: Fundamentals
The endocardium, the innermost heart layer, receives blood from the coronary arteries and contains the branches responsible for the heart's electrical conduction system. It also provides the pathway for blood supply to the valves.
Category: Fundamentals
People with group O blood are considered universal donors because they do not have antigens on their RBCs. People with group AB blood are considered universal recipients because they have no antibodies to the transfused blood.
Category: Fundamentals
Blood transfusions are actually transplantations of tissue (blood) from one person to another. It is important that the recipient not have antibodies to the donor's RBCs. If this were to occur, there could be a hypersensitivity reaction.