Monitorage d’urgence

Abstract

Monitoring of critically-ill patients, both in pre-hospital and hospital practice must be continuous and reliable and to be effective, should cover a number of vital parameters. Electrocardiography, which will detect problems of cardiac rhythm, has become standard in patient care but is not sufficient alone to provide effective monitoring. Arterial blood pressure measurement may be either non-invasive or invasive and manual or automatic. Although invasive monitoring is the most reliable technique it is not easy to perform in the pre-hospital situation and should be restricted to use in patients in a critical condition. Monitoring of ventilation requires continuous recording of oxygen saturation using pulse oxymetry. This parameter is related to arterial oxygen saturation but may be influenced by a number of factors. The values recorded must therefore be interpreted in the light of the patient’s overall condition. Other ventilatory parameters which are often measured include tidal and minute volumes, frequency of ventilation and inflation pressure. These values are essential for all patients on mechanical ventilation to permit the ventilator to be set to the patient’s requirements. The measurement of end–tidal C0 2 gives information, not only about the ventilation but also of the haemodynamic status of the patient. Analysis of capnography curves provides information about a number of conditions such as bronchospasm, circulatory failure or the effectiveness of external cardiac massage. Finally a current development in monitoring is on–site blood chemistry. This allows rapid bedside evaluation of acid-base status, electrolytes and other key chemico–pathological markers. These new techniques promise to be a major aid in diagnosis but have yet to be evaluated properly in pre–hospital practice.