Doppler-based renal resistive index for prediction of renal dysfunction reversibility: A systematic review and meta-analysis.
OBJECTIVE
Doppler-based renal resistive index (RI) might help in distinguishing transient from persistent acute kidney injury (AKI). The main objective of these systematic review and meta-analysis was to investigate the diagnostic performance of RI in predicting short-term reversibility of AKI.


METHODS
A systematic review of the literature was performed. Relevant studies were identified in Pubmed and Cochrane databases covering the years 1985 to 2013 and reviewed independently by 3 authors. Renal transplant recipients were excluded from this analysis. The summary estimates were computed using a random-effects model based on the DerSimonian and Lair meta-analytic method.


RESULTS
Among the 154 unique articles identified, 9 studies were included. Of the 176 patients in these studies with elevated RI or pulsatility index, 146 (83%) had a persistent AKI vs 44 (16%) of the 273 patients with normal values. Elevated RI or pulsatility index was associated with an increased risk of persistent AKI (odds ratio, 29.85; 95% confidence interval [CI], 8.73-102.16; P < .00001) with significant heterogeneity (I(2) = 75.0%, P < .0001). The pooled sensitivity and specificity were 0.83 (95% CI, 0.77-0.88) and 0.84 (95% CI, 0.79-0.88). The summary positive and negative likelihood ratios were 4.9 (95% CI, 2.44-9.87) and 0.21 (95% CI, 0.11-0.41).


CONCLUSIONS
These results suggest that an elevated RI may be a predictor of persistent AKI in critically ill patients. Further studies are warranted, however, to clarify the exact test performance given the marked heterogeneity among the included studies.
Réanimation médico-chirurgicale, Hôpital Nord, avenue Albert Raymond, 42270 St Priest en Jarez, France, Université Jean Monnet, Saint-Etienne, France.
Sebastien
S
Ninet
Réanimation médicale, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, 1 place de l'Hôpital-BP 426, 67091 Strasbourg Cedex, France.
David
D
Schnell
Service d'Anesthésie-Réanimation II, avenue de Magellan, CHU de Bordeaux, F-33604 Pessac, France, Université de Bordeaux, Bioingénierie tissulaire, U1026, 146 rue Léo-Saignat, F-33000 Bordeaux, France.
Antoine
A
Dewitte
Réanimation médico-chirurgicale, Hôpital Nord, avenue Albert Raymond, 42270 St Priest en Jarez, France, Université Jean Monnet, Saint-Etienne, France.
Fabrice
F
Zeni
Réanimation médicale, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, 1 place de l'Hôpital-BP 426, 67091 Strasbourg Cedex, France.
Ferhat
F
Meziani
Réanimation médico-chirurgicale, Hôpital Nord, avenue Albert Raymond, 42270 St Priest en Jarez, France, Université Jean Monnet, Saint-Etienne, France; Thrombosis Research Group, EA 3065, Saint-Etienne University Hospital and Saint-Etienne Medical School, Saint-Etienne, France.
Michael
M
Darmon
D058186:Acute Kidney Injury / Q000175:diagnosis / Q000000981:diagnostic imaging*; D016638:Critical Illness; D006801:Humans; D007668:Kidney / Q000098:blood supply* / Q000000981:diagnostic imaging; D011673:Pulsatile Flow; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance
Acute kidney injury; Critically ill; Doppler ultrasonography; Renal resistive index; Sensitivity; Specificity