Measurement of pulsus paradoxus

Pulsus paradoxus is a valuable clinical sign when there is a greater than 10 mm Hg drop in peak systolic blood pressure during normal inspiration. Although the exact mechanism is not known, tense fluid accumulation within the pericardial sac impairs left ventricular filling during inspiration when right ventricular filling is increased. This causes an exaggerated reduction in systolic blood pressure during inspiration. Critical care nurses need to become familiar with the three methods of measuring pulsus paradoxus: palpation, cuff sphygmomanometry, and arterial wave formation. Nurses should practice and become skilled at measuring a greater than 10 mm Hg change.