The following is a summary of “Impact of rigid cervical collars on the vital signs and cervical vasculature: Should we be on the alert for anything?,” published in the April 2023 issue of Emergency Medicine by Tatliparmak, et al.

For a study, researchers sought to investigate the effects of Rapid Cervical Collar (RCC) application on vital signs and the physiology of neck vascular structures. 

The study was designed as a prospective interventional study on 11 volunteers, and the factors that could affect their hemodynamics were standardized before measurements. They measured and compared the vital signs and various parameters of the neck vascular structures, including the cross-sectional area (CSA) of the internal jugular vein, the diameter of the common carotid artery (CCA), peak systolic velocity (PSV), end-diastolic velocity (EDV), time-averaged maximum velocity (TAMAX), Pulsatility Index, Resistivity Index, time-averaged mean velocity (TAMEAN), and Volume Flow (FV) before and after RCC application under the guidance of ultrasonography (USG).

The results showed that 10 minutes of RCC application led to a decrease in heart rate by 7.9 bpm (95% CI 4.84–10.98) (pre-collar 74.73 + −8.84, post-collar 66.82 + −9.05, P < 0.001), a corresponding decrease in systolic blood pressure by 7.18 mmHg (95% CI 2.11–12.25) (pre-collar mean 115.82 mmHg + −12.55, post-collar mean 108.64 mmHg + −11.46, P = 0.01), and a reduction of 108.55 mL/min of mean common carotid artery blood volume (95% CI 22.28–194.82) (pre-collar 590.14 mL/min + −194.63, post-collar 481.59 mL/min + −279.36, P = 0.019). In addition, the CSA of the internal jugular vein decreased by 0.17 cm2 (95% CI 0.05–0.29) (pre-collar CSA 0.53 + −0.29, post-collar CSA 0.36 + −0.17, P = 0.012). Furthermore, the study found that the internal jugular vein collapsed more than the common carotid artery following the pressure applied by RCC.

In conclusion, RCC application for 10 minutes in healthy volunteers was associated with decreased heart rate and systolic blood pressure. It reduced blood volume in both the common carotid artery and the internal jugular vein. The findings of the study may have implications for the use of RCC in emergency settings, particularly in patients with compromised cardiovascular function.

Reference: sciencedirect.com/science/article/abs/pii/S0735675723000190