Impact of Cervical Collars on Intracranial Pressure Values in Traumatic Brain Injury: A Systematic Review and Meta-Analysis of Prospective Studies

Background Spinal cord injury (SCI) is present in around 2-4% of trauma victims. More than half of this injuries are located at the cervical region. Twenty percent of victims with cervical spinal trauma and 5% of patients with severe traumatic brain injury (TBI) will have an SCI. Cervical immobilization with rigid or semirigid collars is routinely used as prophylactic or definitive treatment intervention in general trauma care. An important adverse effect of cervical collars application is the increase in intracranial pressure (ICP) values. This systematic review and meta-analysis aim to estimate the overall magnitude of ICP changes after cervical collar application. Methods Major electronic databases (Ovid/Medline, Embase and Cochrane Library) were systematically searched for prospective studies that assessed ICP changes after cervical collar applications. Study level characteristics and ICP values before, during and after cervical collar application, were extracted. The meta-analysis was performed using random-effects model. Results Five studies comprising 86 patients were included in the systematic review and the quantitative synthesis. The overall increase in ICP after collar application was statistically significant (weighted mean difference [WMD] = 4.43; 95%CI 1.70, 7.17; P < 0.01), meaning an overall ICP increase of approximately 4.4 mmHg. The decrease in ICP values after collar removal reached statistical significance (WMD = - 2.99; 95%CI - 5.45, - 0.52; P = 0.02), meaning an overall ICP decrease of approximately 3 mmHg after collar removal. ICP values before and after cervical collar application were not statistically significant (WMD = 0.49; 95%CI - 1.61, 2.59; P = 0.65), meaning no ICP change. Conclusions Heterogeneous studies of application of cervical collars as a partial motion restriction strategy after injuries have demonstrated increases in ICP in TBI patients. Increases in ICP can induce complications in TBI patients. Appropriate selection criteria for cervical motion restriction in TBI patients need to be considered.