‘You can’t clear the cervical spine until the patient wakes up!’ How often have you heard this said about a patient with severe traumatic brain injury who may not ‘wake up’ for weeks, if at all?
A controversial area, but many institutions now allow collar removal if a neck CT scan is normal. Does this rule out injury with 100% sensitivity? No – but it probably pushes the balance of risk towards removing the collar – an intervention with no evidence for benefit and plenty of reasons why it may be harmful to ventilated ICU patients. For example, clearing the cervical spine based on MDCT was associated with less delirium and less ventilator associated pneumonia, both of which have been associated with increased mortality in critically ill patients (this is referenced in the paper below).
The UK’s Intensive Care Society has had pragmatic guidelines along these lines since 2005, which can be found here. This month’s Intensive Care Medicine publishes an updated literature review providing some further support to this approach.
PURPOSE: Controversy exists over how to ‘clear’ (we mean enable the clinician to safely remove spinal precautions based on imaging and/or clinical examination) the spine of significant unstable injury among clinically unevaluable obtunded blunt trauma patients (OBTPs). This review provides a clinically relevant update of the available evidence since our last review and practice recommendations in 2004.
METHODS: Medline, Embase. Google Scholar, BestBETs, the trip database, BMJ clinical evidence and the Cochrane library were searched. Bibliographies of relevant studies were reviewed.
RESULTS: Plain radiography has low sensitivity for detecting unstable spinal injuries in OBTPs whereas multidetector-row computerised tomography (MDCT) approaches 100%. Magnetic resonance imaging (MRI) is inferior to MDCT for detecting bony injury but superior for detecting soft tissue injury with a sensitivity approaching 100%, although 40% of such injuries may be stable and ‘false positive’. For studies comparing MDCT with MRI for OBTPs; MRI following ‘normal’ CT may detect up to 7.5% missed injuries with an operative fixation in 0.29% and prolonged collar application in 4.3%. Increasing data is available on the complications associated with prolonged spinal immobilisation among a population where a minority have an actual injury.
CONCLUSIONS: Given the variability of screening performance it remains acceptable for clinicians to clear the spine of OBTPs using MDCT alone or MDCT followed by MRI, with implications to either approach. Ongoing research is needed and suggestions are made regarding this. It is essential clinicians and institutions audit their data to determine their likely screening performances in practice.
Clinical review: spinal imaging for the adult obtunded blunt trauma patient: update from 2004
Intensive Care Med. 2012 Mar 10. [Epub ahead of print]