Fluid resuscitation is a key element for the management of critical care patients. However, it is uncertain whether balanced crystalloids may be preferred over normal saline (NS) in trauma patients. Therefore, the current meta-analysis compared the efficacy and safety of balanced crystalloids with NS in trauma resuscitation.

The online search for articles relevant to our study objective was conducted in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and Scopus. This search was limited to randomized controlled trials (RCTs) available in English language. The primary outcome of our study was all-cause mortality, and secondary outcomes were incidence of acute kidney injury (AKI), length of intensive care unit (ICU) stay, ventilator-free days, need for renal replacement therapy (RRT), and base deficit. The statistical analyses were performed using RevMan 5.4.1, and bias assessment was performed using the Cochrane risk of bias tool (ROB-2).

Six distinct RCTs involving 1950 trauma patients were included. The pooled analyses revealed that NS was associated with decreased mortality in traumatic brain injury (TBI) patients (OR: 1.35; 95 % CI: 1.06 to 1.72; p  = 0.02), but not in trauma patients without TBI (OR: 1.17; 95 % CI: 0.47 to 2.90; p  = 0.74). Similarly, more ventilator-free days were observed in the NS group than in the balanced crystalloids group among TBI patients (MD: −0.67 days; 95 % CI: −0.86 to −0.48; p   <  0.00001), but not in trauma patients without TBI (MD: 3.0 days; 95 % CI: −3.36 to 9.36; p  = 0.36). On the other hand, no significant difference was observed in total volume of study fluid administered, AKI incidence and length of ICU stay among patients with or without TBI.

In trauma patients with TBI, NS was associated with lower mortality and more ventilator-free days than balanced crystalloids, whereas no significant difference was noted in trauma populations without TBI. Moreover, there was no significant difference between NS and balanced crystalloids in terms of AKI incidence, need for RRT, and ICU stay, suggesting that balanced crystalloids remain a safe and reasonable option for trauma resuscitation.