Davis P, Turner-Gomes S, Cunningham K, Way C, Roberts R, Schmidt B. Precision and accuracy of clinical and radiological signs in premature infants at risk of patent ductus arteriosus. Arch Pediatr Adolesc 1995; 149: 1136-1141.
Evidence:
Prospective cohort study (Level 1b).
Comparison of clinical findings with echocardiography (Gold Standard).
Results:
Outcome | Key Results | Comments |
Detection of PDA by clinical examinationv Echocardiography (Gold-Standard) | Murmur LR+ 3.23 (CI 1.2 to10) LR- 0.67 (CI 0.53 to 0.93) Bounding Pulses LR+ 1.65 (CI 0.79 to 3.53) LR- 0.77 (CI 0.48 to1.16) | Clinical signs poor predictors of PDA. |
Comment:
In this study, a high percentage of babies with PDA had no murmur (Murmur alone only 42% sensitive). Similarly bounding pulses were a poor independent predictor of a PDA. However, the combination of murmur and bounding pulses had a positive predictive value of 77%.
We can also calculate post-test probability for patent ductus arteriosus using the likelihood ratios (LRs) from this study. For presence of a murmur alone, if we assume a pre-test probability of 65% (Costeloe et al 2000), and positive LR of 3.23 then our post-test probability is increased to 86%. However if no murmur is present and negative LR is 0.67 post-test probability falls only to 55%. For an increased pulse volume, with a pre-test probability of 65%, post-test probability is increased to 75% when there are bounding pulses but falls only to 59% when bounding pulses are absent.
Clinical Bottom Line:
Echocardiography is required to confirm or refute a diagnosis of PDA.
Costeloe K, Hennessy E, Gibson AT, Marlow N, Wilkinson AR. The EPICure Study: Outcomes to Discharge from Hospital for Infants Born at the Threshold of Viability. Pediatrics 2000; 106: 659-671.
Appraisers: Don Urquhart, Richard Nicholl