Table 1

Physiological Variables and Their Clinical Relevance

Physiological VariableClinical Relevance
Heart sounds
 First heart soundAssociated with ventricular contraction status
 Third heart soundAssociated with early diastolic filling
Thoracic impedanceAssociated with fluid accumulation and pulmonary edema
Respiration
 Respiration rateRapid shallow breathing patterns associated with shortness of breath
 Ratio of respiration rate to tidal volume
Heart rateIndicator of cardiac status
ActivityGlobal patient status and fatigue