Roy CL, et al. Does this patient with a pericardial effusion have cardiac tamponade? JAMA. 2007 Apr 25;297(16):1810-8.
Systematic review of studies assessing accuracy of history, physical examination, and basic diagnostic tests for the diagnosis of cardiac tamponade.
Only searched Medline for English-language articles, but included reference lists of articles and textbooks.
Articles selected by two independent authors and disagreements resolved by a third reviewer.
Inclusion criteria: studies comparing various history, physical exam, and diagnostic test findings to a reference standard of either pericardiocentesis with right heart catheterization and echocardiography
Excluded studies of patients with cardiac tamponade after cardiac surgery and those with fewer than 15 patients
Table 3 shows the sensitivity and specificity of pulsus paradoxus from one study (N=65) comparing this finding between patients with pericardial effusion with tamponade to those with pericardial effusion without tamponade.
Table 4 shows a pooled analysis of eight studies (N=295) comparing sensitivity of pulsus paradoxus to other physical exam findings.
A pulsus paradoxus greater than 10 mm Hg among patients with a pericardial effusion helps identify patients at risk for cardiac tamponade, but additional testing is required for a definitive diagnosis.
How I found it
Checked Dynamed under tamponade-physical exam. Found reference to this review. Also, tried in PubMed with this string: pulsus paradoxus tamponade sensitivity
No relevant studies that were more recent.