As the need for mechanical circulatory assistance: increasing, advances and development in its structure, function, and continue to influence the outcome and the patient benefit. The currently available circulatory assist devices are the artificial cardiac pacemaker, the intraaortic balloon pump, the ventricular assist devices, and the implantable cardioverter defibrillator.
The aim of the study is to understand different hemodynamic and physiopathologic changes occur with use of these mechanical circulatory assist devices and understanding the anesthetic management of patients with these devices.
A) Artificial cardiac pacemaker: Pacemakers consist of a power source (battery) that supplies energy for stimulation and other pacemaker functions, circuit, for sensing and regulation of stimulation, and leads that connect the power source and electronic circuitry to electrodes.
Artificial pacing is indicated for treatment of pen stent bradycardia of any origin if it compromises hemodynamics or predisposes to ventricular irritability manifested by premature beats (ventricular tachycardia (VT). Complications following pacemaker; Pneumo (hemo)-thorax Thromboembolism, pulse Lead disk subcutaneous emphysema generator erosion, myocardial perforation, arterial lead placement, battery depletion, brachial plexus injury, arrhythmias, infection syndrome, and malfunction.
B) The intraaortic balloon pump: The IABP is a catheter mounted intravascular devices designed to improve the balance between myocardial oxygen supply and demand while increasing systemic perfusion to a modest degree, other components of IABP include a pump, a gas source, and a microprocessor
Console. The primary indications for IABP in cardiac surgical patient are inability to separate from CPB, poor hemodynamic function, and ongoing ischemia following CPB despite increasing drug support.
Myocardial function often improves with the use of the IABP, and systemic perfusion and vital organ function are preserved. It is crucial to control heart rate and suppress atrial and ventricular dysrhythmias to ensure proper balloon timing. As cardiac function returns, the assist ratio is gradually weaned from every beat to every other beat and so on assuming no further cardiac deterioration, and then removed. Complications associated with the IAP are primary related to ischemia distal to the site of balloon insertion. Direct trauma to the vessel, arterial obstruction, and thrombosis are common complications, although aortic perforation and balloon rupture occur rarely. Platelet destruction and thrombocytopenia may also occur,
C) Automatic implantable Cardioverter defibrillator: Recurrent ventricular tachycardia or ventricular fibrillation that can result in sudden death in the survivor of cardiac arrest may be treated with an automatic implantable cardioverter defibrillator (AICD)• it senses the onset of these ventricular dysrhythmias and delivers a synchronized 25- joule electrical discharge. Complications include Pneumothorax, Pocket erosion, Lead dislodgement, Hemothorax, Pocket hematoma Lead perforation Subclavian artery puncture, Pocket seroma, , Loose set SC Air embolism, Pocket infection, Failure , Bleeding, Malposition, Brachial plexus injury, and Diaphragms Subclavian arteriovenous fistula.
Contraindications: Implantation of an ICD is contraindicated in any patient who has a treatable cause of ventricular arrhythmias such as acute myocardial infarction, myocardial ischemia, electrolyte imbalance, drug toxicity, hypoxia, or sepsis.
D) The ventricular assist devices: The VAD a device that is designed to assist replaces the function of either the right or left ventricle. In the absence of right or left ventricular ejection, the RV supports the pulmonary circulation, while LVAD provides systemic perfusion respectively. The VADs are positioned intracorporeally in the anterior abdominal wall or within a body cavity other than the pericardium. Extracorporeal VADs may be located in a paracorpreal position, along the patient's anterior abdominal wall, or externally, in the patient's bedside. Infrequently, demands despite maximal pharmacologic therapy support are unable to meet systemic metabolic needs, and insertions of these devices that actually pump blood and bypass either the left or the right ventricle are required. The e devices are effective because the injections producing myocardial dysmotion takes place intraoperatively and, are important, is often revers it, A second group of patients who have shown benefit from assist devices are those with chronic heart failure. These devices allow for hemodynamic support as a temporary means prior to heart transplantation. Complications of Ventricular assist devices are inadequate LVAI flow, right ventricular failure, hemorrhage, thromboembolism, infection, multisystem organ failure, device malfunction, and pump dependency.
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