Hypertonic Saline Solution Versus Mannitol for Brain Relaxation During Craniotomies: An Updated Meta-analysis
Artur Menegaz de Almeida1, Patrícia Viana2, Gabriel Marinheiro dos Santos Bezerra3, Jessica Hoffmann Relvas4, Lucca Lopes5, Gustavo Lima Guilherme1, João Antônio Zanette Giusti1, Paloma Oliveira1, Mauro André Azevedo Silva Kaiser Cabral1, Renato Carvalho Santos6, Khalid Medani7
1Federal University of Mato Grosso, 2Catarinense Extreme-South University, 3Federal University of Ceará, 4Department of Internal Medicine, Mandaqui Hospital Complex, 5Sciences Medical School of Santos, 6São Lucas Hospital, 7Department of Occupational Medicine, Kaiser Permanente Medical Center
Objective:
This meta-analysis intends to provide an updated review of the published literature by comprising the largest published to date on the comparison of HTS with MAN for brain relaxation during craniotomies.
Background:
The choice between mannitol and hypertonic saline as the preferred osmotic agent for achieving brain relaxation during craniotomies still lacks a definitive consensus in the existing body of research. This lack of agreement can be attributed to limited sample sizes and substantial heterogeneity among the trials included in previous studies.
Design/Methods:
MEDLINE, Embase, and Cochrane databases were systematically searched until August 02, 2023. Data was examined using the Mantel-Haenszel method and 95% confidence intervals (CIs). Heterogeneity was assessed using I² statistics. Meta-regression analysis was conducted to evaluate a possible link between Brain Relaxation Score (BRS) and tumor volume. R, version 4.2.3, was used for statistical analysis.
Results:
A total of 16 RCTs and 1,031 patients were included, of whom 631 (61%) underwent surgery for supratentorial tumor resection. Compared with mannitol, hypertonic saline achieved better rates of BRS (80% vs. 71%; OR 1.68; 95% CI 1.22–2.33; p=0.001; I²=0%), which was also demonstrated in the subgroup analysis of supratentorial brain tumor patients (78% vs. 65%; OR 2.02; 95% CI 1.36–2.99; p=0.0005; I²=0%); a minor number of patients requiring a second dose of osmotic agent (14% vs. 28%; OR 0.43; 95% CI 0.27–0.69; p=0.0003; I²= 0%); a lower fluid intake (MD -475.9341 mL; 95% CI -818.8952– -132.9730; p=0.007; I²=88%); and lower urine output (MD -462.0941 mL; 95% CI -585.3020– -338.8862; p=<0.001; I²=96%). Hospital length of stay and focal neurological deficits did not reach a statistically significant difference.
Conclusions:
Our study shows that HTS has better benefits than mannitol, not only for brain relaxation. Furthermore, the study reveals, utilizing subgroup analysis, that patients with supratentorial brain tumors are more likely to benefit from HTS administration.