Fifteen consecutive patients who had been resuscitated from cardiac arrest and transferred immediately to an Intensive Care Unit were studied. Measurements of intraarterial pressure, cardiac output and systemic vascular resistance demonstrate that 'cuff' blood pressure may not always be related to intraarterial pressure or cardiac output and cannot be used for diagnostic, therapeutic, or prognostic purposes. Following resuscitation, a palpable pulse was present in each of these patients, but did not correlate with adequacy of cardiac output. Too often we hear during a cardiac arrest the question 'Does the patient have an output?', when we should really be asking 'Does the patient have a pulse?'. The palpation of a pulse is a simple and important indication of spontaneous cardiac activity. However cardiac output must be measured and it's adequacy cannot be inferred from this basic clinical measurement.