Should we use cervical collars for neck stabilization in trauma patients? Evidence from a systematic review with meta-analysis

Introduction: The aim of this study was to evaluate the impact of neck stabilization with cervical collar on optic nerve strength diameter. Methods: A literature search of PubMed, Scopus, EMBASE and Web of Science databases from their inception to December 22, 2021 was conducted. The search was conducted using the terms: “cervical collar” OR “collar” AND “intercranial pressure” OR “optic nerve strength diameter” OR “ONSD” OR “traumatic” OR “brain injury” and restricted to English language documents. Results: The pooled analysis showed that optic nerve sheath diameter (ONSD) without collar was 4.5 ± 0.9mm. After insertion of the cervical collar and stabilization of the cervical spine for 20 minutes, an increase in ONSD was observed (4.9 ± 1.5mm; SMD = 0.89; 95%CI: 0.39 to 1.39; p =0.01). In clinical trial ONSD at baseline (4.8 ± 0.9mm) and 20-minutes after fitting the flange (5 ± 0.9mm; SMD = 0.22; 95%CI: -0.07 to 0.51; p =0.13). In experimental trials, the pooled analysis showed statistically significantly higher ONSD values for a 20-minute cervical collar application (4.86 ± 1.74 vs. 4.35 ± 0.91mm, respectively; SMD = 1.05; 95%CI: 0.46 to 1.65; p <0.001). Discussion and Conclusion: Our meta-analysis showed that stabilizing the cervical spine with a cervical collar increases the intracranial pressure even in healthy volunteers, with the NextSplit collar being the least stressful. Large prospective, randomized studies are needed to confirm the obtained results.