Occipitocervical dissociative injuries: common in blunt trauma fatalities and better detected with objective computed tomography-based measurements.
ABSTRACT Occipitocervical injuries (OCIs) are generally not common in blunt trauma victims, but autopsy studies of blunt trauma fatalities consistently report a high prevalence of these injuries. New computed tomography (CT)-based quantitative criteria have recently been developed for use in assessing the occipitocervical spine. The efficacy of these new criteria for detecting OCI would be supported if the high prevalence of OCI in blunt trauma fatalities can also be detected using these objective CT-based criteria.
To test the hypothesis that the prevalence of OCI in blunt trauma fatalities, determined using objective CT-based measurements and reliable reference data, will be similar to the prevalence reported in prior autopsy studies.
Retrospective assessment of the CT examinations of blunt trauma fatalities at a Level 1 trauma center.
Seventy-four consecutive patients who died within 21 days of blunt trauma and had a CT examination of the cervical spine.
Quantitative measurements from CT examinations of the occiput-C1 and C1-C2 levels.
Measurements were made on a Picture Archiving and Communication System (PACS) from the CT images that were originally used for diagnosis and also using imaging software that allowed for precisely reoriented slices that correct for variations in the alignment of the upper cervical spine. The prevalence of abnormal measurements found by each method and the interobserver reliability of the measurements were assessed.
At least one abnormal measurement was found in 50% of cases based on measurements made on the PACS, and in 34% of cases using measurements from carefully reoriented images. At least three abnormal measurements were found in 22% and 14% of patients, respectively. Only one of the patients had been diagnosed as having an OCI before death. Interobserver reliability measurements of more than 80% were found for most measurements.
Using precise CT-based measurements and reliable reference data for diagnosis of occipitocervical dissociative injuries, the prevalence of injuries in severely injured blunt trauma patients was close to the levels reported in prior autopsy studies (approximately 30%). This supports that with careful measurements, both soft- and hard-tissue OCI can be detected by CT. This study is limited by the fact that a gold standard was not available to confirm the injuries.
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ABSTRACT: Abstract Introduction. Prehospital spine immobilization has long been applied to victims of trauma in the United States and up to 5 million patients per year are immobilized mostly with a cervical collar and a backboard. Objective. The training of paramedics and emergency medical technicians on the principals of spine motion restriction (SMR) will decrease the use of backboards. Methods. The training for SMR emphasized the need to immobilize those patients with a significant potential for an unstable cervical spine fracture and to use alternative methods of maintaining spine precautions for those with lower risk. The training addressed the potential complications of the use of the unpadded backboard and education was provided about the mechanics of spine injuries. Emergency medical services (EMS} personnel were taught to differentiate between the critical multisystem trauma patients from the more common moderate, low kinetic energy trauma patients. A comprehensive education and outreach program that included all of the EMS providers (fire and private), hospitals, and EMS educational institutions was developed. Results. Within 4 months of the policy implementation, prehospital care practitioners reduced the use of the backboard by 58%. This was accomplished by a decrease in the number of patients considered for SMR with low kinetic energy and the use of other methods, such as the cervical collar only. Conclusion. The implementation of a SMR training program significantly decreases the use of backboards and allows alternative methods of maintaining spine precautions. Keywords: Emergency Medical Services; humans; spinal injuries/therapy; transportation of patients; cervical vertebrae/injuries; emergency medical services/ methods; emergency medical technicians; immobilization/ methods; spinal motion restriction.Prehospital Emergency Care 02/2014; · 1.86 Impact Factor
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ABSTRACT: Based on the multi-loop circuit method of AC machine a mathematic model is established for the large unit-connected generators, namely the outlet terminal of generators connected to a common busbar, and the transient zero-sequence current and voltage of these generators are simulated and analyzed at different grounding location. Further, making use of the wavelet transform sensitively detecting the singularity of signal, the properties of their value of wavelet transform are analyzed, and a selective transient protection is proposed according to the sign and value of the modulus maxima of wavelet transform. The results of simulation and experiment verify the new protection can correctly detect the generator with ground fault, and discriminate between the internal and external faults.Power System Technology, 2002. Proceedings. PowerCon 2002. International Conference on; 02/2002