释义 |
DictionarySeepumpintra-aortic balloon pump
intra-aortic balloon pump (IABP) a mechanical aid to the circulatory function of the heart that acts to provide internal counterpulsation. The basic components of the device are a catheter tipped with a balloon and a pump machine that inflates the balloon with either helium or carbon dioxide. The balloon is inserted via a femoral artery cutdown and guided under fluoroscopic control to a position in the descending thoracic aorta just distal to the left subclavian artery. In some models, the balloon is tri-segmented. When inflation begins in a tri-segmented balloon, the middle segment is inflated first, then the distal ends inflate simultaneously; there is no occlusion of the aorta. An alternative type of balloon catheter consists of only one segment with a second small balloon just distal to the main one; the smaller balloon partially occludes the aorta only during diastole, thus providing directional flow. The pump console contains signal processing, drive, and timing and control mechanisms for appropriate inflation and deflation. The system also contains a display and diagnostic unit. The physiologic effect of the IABP is to improve coronary blood flow and systemic circulation. It does this by (1) augmenting aortic root pressure during ventricular diastole at the time of maximum blood flow, and (2) reducing the workload of the heart by decreasing the amount of residual blood in the aortic arch, thereby decreasing resistance to the flow of blood from the ventricle. Inflation of the balloon during diastole just after aortic valve closure, and deflation just prior to ventricular systole reduces the pressure workload of the left ventricle and lessens oxygen demand and consumption by the myocardium. Timing of the inflation--deflation cycle is based on the arterial pulse wave configuration seen on the console's display screen. Adjustments to the cycle are made according to the site of arterial wave sampling, heart rate, and the depth of diastolic dip. Indications for employment of the IABP include cardiogenic shock or severe pump failure secondary to acute myocardial infarction or following open-heart surgery, unstable angina resistant to drug therapy, and refractory ventricular irritability after myocardial infarction. The effect of improved oxygenation of the myocardium can result in reversal of ischemic damage resulting from infarction, and limitation of the size of the myocardial infarction. Following insertion of the IABP catheter and initiation of the pumping action, nursing care is focused on proper administration of medications, monitoring the patient's response and the function of the equipment for evidence of safe and effective pumping, observation for ischemia of the limb in which the catheter is inserted, and observation for side effects and complications, such as excessive bleeding from the insertion site or formation of a hematoma, wound inflammation and infection, abdominal or back pain, reduction in platelet count and hematocrit and other signs of clotting abnormalities, and thrombus formation. Nursing care problems associated with IABP include patient anxiety involving fear of the procedure, concerns about coronary angiography and surgery, or lack of knowledge about the procedure and its purpose; the need for cardiovascular and respiratory support; physical discomfort; and limited mobility. The patient with an IABP requires highly skilled nursing care.Intra-aortic balloon pump (IABP). From Polaski and Tatro, 1996.intra-aortic balloon pump Interventional cardiology A device that changes hemodynamic loading conditions in the heart by ↑ mean and peak diastolic BP, and ↓ peak systolic BP; these changes result in ↓ left ventricular end-diastolic pressure, ↑ stroke volume, ↑ cardiac output; the IABP is used primarily for cardiogenic shock after an acute MI, or in severe mitral insufficiency of abrupt onset; the IABP ↑ coronary blood flow, myocardial perfusion, ↑ collateral coronary circulation, improves subendocardial oxygenation, ↓ myocardial O2 consumption Contraindications Acute or significant aortic regurgitation, as IABP exacerbates regurgitation from the aorta into the left ventricle and ↑ left ventricular diastolic filling pressure; IABP is used as a ventricular assist device, pre-, intra- or postoperatively when medical therapy is insufficient by itselfpump (pump) 1. An apparatus that transfers fluids or gases by pressure or suction.2. To force air or fluid along a certain pathway, as the heart does to blood.air pumpA device for forcing air in or out of a chamber.blood pump1. A device for pumping blood. It is attached to an extracorporeal circulation system. 2. A compression sleeve placed about a plastic transfusion bag.breast pumpAn apparatus for expressing milk from the human breast.efflux pumpA cell membrane protein channel that selectively admits or excludes chemicals from the cytoplasm. In some bacteria efflux pumps prevent their cells from accumulating antibiotics, contributing to drug resistance. electronic implantable infusion pump Abbreviation: EIIP A type of infusion pump inserted in the body. The pump, which may be programmable or nonprogrammable, is placed in a subcutaneous pocket and is connected to a dedicated catheter leading to the appropriate compartment or site. infusion pumpA pump to administer fluids into an artery, vein, or enteral tube, beneficial in overcoming arterial resistance, controlling the rate of the fluid and drug administration, or administering thick solutions. The pump can be programmed to set the rate of administration depending on the patient's needs. See: ; electronic infusion device Synonym: intravenous infusion pump See: Infusion Pump INSULIN PUMPinsulin pumpA small battery-driven pump that delivers insulin subcutaneously into the abdominal wall. The pump can be programmed to deliver varying doses of insulin as a patient's need for insulin changes during the day (e.g., before exercise or meals, when physical or psychological levels of stress change). See: illustrationintra-aortic balloon pumpIntra-aortic balloon counterpulsation.intravenous infusion pumpInfusion pump.lymphedema pumpA pneumatic compression device for application to an edematous limb. It works best when combined with elevation of the limb and manual massage. The device, which may be single-chambered or multichambered, is designed to provide calibrated, sequential pressure to the extremity. This action “milks” edema fluid from the extremity. It is essential that the device be used in the early phase of the development of lymphedema. If the affected lymph vessels develop fibrotic changes (i.e., scar tissue), then pneumatic compression devices are of questionable benefit. proton pumpAn enzyme located in the parietal cell of the stomach that excretes hydrogen ions in exchange for potassium ions. The formal name of the proton pump is hydrogen/potassium adenosine triphosphate (H+/K+ATPase). Patient careGastric acids produced by the proton pump aid chemical digestion of foods. Some diseases and conditions are worsened by acid in the stomach (e.g., peptic ulcers, acid reflux disease). Drugs that inhibit the proton pump (proton pump inhibitors such as omeprazole) are used to treat these illnesses. respiratory pumpThose abdominal and thoracic structures that contribute to the expansion and contraction of the lungs. Movement of the chest and abdomen alters central pressures during inspiration and expiration. During inspiration, decreases in intrathoracic pressure draw air into the trachea, bronchi, and lungs and draw blood into the vena cava and right atrium of the heart. During expiration, intrathoracic pressures rise, and air is forced out of the lungs. sodium pumpThe active transport mechanism that moves sodium ions across a membrane to their area of greater concentration. In neurons and muscle cells, this is outside the cell. In many cells, the sodium pump is linked with the potassium pump that transports potassium ions into the cell, also against a concentration gradient, and may be called the sodium-potassium pump. In neurons and muscle fibers, this pump maintains the polarization of the membrane. See: Sodium-Potassium Pumpsmart pumpA programmable infusion device used to control and administer intravenous drugs and limit medication administration errors. Its software may include some or all of the following features: infusion rate programming; dosing limit lockout features; configurations for specific hospital areas (pediatric dosing versus adult or intensive care unit dosing); surgical or anesthetic drug libraries; controls for patient-controlled analgesia; and alert features (alarms or messages that notify users of possible medication errors). stomach pumpA colloquial term for gastric lavage.thoracic pumpThe negative pressure in the chest during inspiration that pulls venous blood into the vena cava and right side of the heart so that it can circulate to the lungs.venous plexus foot pumpA device that alternates between applying pressure and no pressure on the sole of the foot. The change in pressure allows venous blood vessels to alternately fill and then empty, thus imitating the effects of walking on the veins of the lower extremities. The pump is used to prevent deep vein thromboses (DVTs) in patients at high risk because of a previous history of DVTs, hypercoagulable states, or prolonged bedrest. AcronymsSeeIABP |