Monitoring techniques in shock

Monitoring of a variety of cardiovascular functions is necessary to make the diagnosis of shock and to select and follow the response to appropriate therapy. The adequacy of peripheral perfusion is assessed by the measurement of hourly output of urine, auscultatory blood pressure and arterial blood gases and by bedside evaluation of the adequacy of cerebral, coronary and cutaneous blood flow. Elucidation of the hemodynamic mechanism of shock primarily involves the differentiation between inadequacy of venous return to the heart and impairment of cardiac function. Use of a properly functioning catheter to monitor central venous pressure and judicious use of infusions of dextran are the most effective means of making this distinction. Accurate measurement of arterial and venous pressure often requires the use of a strain gauge transducer. Monitoring of the response to therapy requires that a knowledgeable and attentive physician frequently assess arterial and venous pressures, heart rate and rhythm, urinary output, blood gases, skin temperature and sensorium.