HYPOTENSIVE RESUSCITATION

Hypotensive Resuscitation

Hypotensive Resuscitation

Introduction

It is a shock which is exclusive or predominant cause failure of the heart pump. This failure is responsible for a significant drop in cardiac output. Whatever the etiology, the common characteristic hemodynamics of cardiogenic shock is a reduction of early and significant decrease in cardiac output by stroke volume of the left ventricle.

The decrease in cardiac output primitive has the first consequence of a fall in blood pressure. The intensity of hypotension can lead to disorders of the microcirculation that are generators of hypoxia, acidosis with peripheral blood sequestration, effective hypovolemia and decreased venous return. The compensatory mechanisms brought into play by reflex arterial or cardio-pulmonary vasoconstriction and tachycardia. The latter mechanism is multiple: Rise of catecholamine and sympathetic tone, bringing into play of the renin-angiotensin system, vasopressin secretion.

Some aggravating factors in the cardiogenic shock will affect more the compensatory mechanisms. Rhythm disorders reduce the time to ventricular diastolic filling, coronary perfusion and increases MVO2. Conduction disorders may prevent reflex tachycardia. The chronic hypoxia impairs myocardial contractility. Severe and associated acidosis and it increases peripheral sequestration and reduces right ventricular preload. These aggravating factors create a vicious circle, as a consequence of heart failure, they contribute to the increase (Mathias, 1999).

Treatment

Mortality of primary cardiogenic shock during myocardial infarction ranges from 85 to 100%. The goals of treatment are to normalize hemodynamics by restoring the noble organ perfusion and limit necrosis. Must be removed and or treat an aggravating factor: Metabolic acidosis, hypoxemia, arrhythmias. Drug treatment is based primarily on the type bleated agonist dobutamine. It is a symptomatic treatment for recovering cardiac output sufficient pressure to correct tissue perfusion by increasing blood pressure. The dosage should be adapted to the clinic. It is usual to start at 7.5 gamma / kg / min. Adrenaline is used only temporarily in difficult situations to help restore an acceptable mean arterial pressure. It has the potential to increase after load (Mukai, 2002).

Goals for Patients

The absolute priority is the diagnosis and control as quickly as possible to the source of bleeding: surgical homeostasis, arteriography, embolization of a fractured pelvis or uterus post pregnant bleeding, endoscopy for gastrointestinal bleeding, should never be delayed because it is the key to solving the problems posed by hemorrhagic shock. Hypotension was complicated by shock is common in the severe trauma, from the initial management. Many studies conducted in the United States and France, show that low blood pressure was found in serious injuries, from the initial phase of their care (Rutan, 1992).

Causes of Hypotension

The pathophysiology of hypotension initial trauma is poorly understood but several factors combine to cause a decrease in blood pressure may be complicated by shock. Hypotension results from the decrease in venous return to right heart (preload), which may be increased or caused by a mechanical obstruction such as a tension pneumothorax or hemopericardium. Setting positive pressure ventilation after endotracheal intubation, which is one of the first acts of the pre-hospital respiratory involved in this ...