Source: J Indian Med Assoc  |  Posted 7 years ago

By Jill Stein

PARIS, FRANCE -- April 20, 2004 -- New data indicate that there is marked C-spine movement during the removal of protective helmets in healthy subjects, particularly closed-face helmets.

Based on this evidence, patients who sustain a motor vehicle accident may be at risk spinal injury when their helmet is removed for the purpose of airway access, the investigators said, during their presentation here on April 20th at the 13th World Congress of Anaesthesiologists.

Orlando Hung, MD, Professor, Departments of Anesthesia, Surgery, and Pharmacology, Dalhousie University, Halifax, Canada, and his team determined the magnitude and location of C-spine movement during the removal of open-faced and closed-faced helmets in 10 healthy volunteers.

"Evidence exists that demonstrates benefits from wearing protective helmets for many recreational and sports activities, such as football, hockey, rollerblading, riding motorcycles, and auto racing," Dr. Hung said.

He also observed that cadaver studies have shown that significant C-spine movement occurs during helmet removal. Such studies also have shown that helmet and shoulder pad removal in the unstable C-spine result in significant angulation in flexion and narrowing of the cervical canal.

In the present study, each subject was studied under 4 different conditions -- wearing an open-faced helmet with a relaxed neck; wearing an open-faced helmet with a simulated stiff neck; wearing a closed-face helmet with a relaxed neck; and wearing a closed-faced helmet with a simulated stiff neck.

A dynamic lateral C-arm fluoroscopy was recorded for off-line analysis of the C-spine during helmet removal.

Results showed that marked complex C-spine movement occurred (initial flexion up to 14 degrees followed by extension up to 15 degrees) during the removal of the helmets. The movements were mostly between C3-5.

The study also found significantly more C-spine movement with closed-face compared with open-face helmets.

Although there were slight differences in C-spine movements within the same volunteers with a relaxed and stiff neck during helmet removal, these were not significantly different.

"Although closed-face helmets may provide additional protection to facial injury, our data suggest that there is significant movement that occurs in the higher C-spine (between C3-5) during helmet removal of closed-face compared to open-faced helmets," Dr. Hung said. This means potential C-spine injury would occur during helmet removal following motor vehicle accidents."

The potential risk of C-spine injury thus poses a challenge in the management of the patient who may require emergency airway management, particularly when a closed-faced helmet is being used, he added.

"The fact that there's about a 30 degree C-spine movement when you remove the helmet means that there is a risk that the patient with an unstable C-spine fracture can be converted to a quadriplegic," he said.

Dr. Hung advised against helmet removal in these patients and instead recommended airway access via nasal intubation.

[Study title: Evaluation of cervical spine movement during helmet removal. Abstract 359]