[Measurement of residual gastric volume: in search of better evidence].

INTRODUCTION Measurement of residual gastric volume is a frequent practice in chronic patients, but there is lack of consensus on the convenience of reintroducing or discarding aspirated gastric content (AGC). OBJECTIVE Determine the grade of scientific evidence on the efficacy of two interventions -reintroduction/rejection- of AGC in chronic patients. MATERIAL AND METHODS Systematic review of the evidence available on the convenience of reintroducing or discarding ACG. PROCEDURE a) establishment of inclusion/exclusion criteria; b) determination of the search strategy (keywords and itineraries); c) dumping of databases: MEDLINE, CINAHL, CUIDEN, IME, SCIELO and COCHRANE. Search for indirect method and manual dumping of indexes; d) independent and contrasted critical reading, using the CASPe template; and e) contrast of critical analysis results. RESULTS Search itineraries generate more than 800 references that once purged make it possible to select 54. After reading them, only 4 really focused on the questions related with the reintroduction/rejection of AGC: 2 revisions, 1 observational study and a random clinical trial with a small sample. Meta-analysis techniques could not be used due to the heterogeneity of these studies. Thus, the results of the study were analyzed separately. Using this procedure, a final result was obtained that showed a low grade of scientific evidence. CONCLUSIONS There is limited scientific evidence on the convenience, safety and benefits of both interventions. It is difficult to establish a care protocol, so that we suggest performing an experimental study to establish the indications and contraindications of both interventions.