Entrapped patients—time for an extrication re-think?
Being trapped following a motor vehicle collision (MVC) provides its own set of challenges for the patient and the rescuers. Fire and rescue service (FRS) extrication strategies have developed on the basis of minimal patient movement in order to avoid exacerbation of potential spinal injury. These procedures mandate that all casualties should be treated as if they have a spinal injury until proven otherwise. Despite this, our understanding of the type and rate of spinal injuries in those trapped following an MVC is limited as is our understanding of the type and rate of time-critical injuries within the entrapment group. The research team argues that without this understanding, extrication approaches cannot be contextualised or understood in terms of potential benefits and harms to our patients.
This retrospective database study interrogated the Trauma Audit and Research Network (TARN) database. Patients were included if they were admitted to an English hospital following an MVC from 2012 to 2018. In total, 426 135 major trauma cases were identified, of which 63 625 patients were included: 6983 trapped and 56 642 not trapped.
Trapped patients had a higher mortality (8.9% vs 5.0%, p<0.001), a higher injury severity score (ISS) (18 [IQR 10–29] vs 13 [IQR 9–22]) and more deranged physiology with lower blood pressures, lower oxygen saturations and lower Glasgow Coma Scale (all p<0.001). Trapped patients had more significant injuries of the head, chest, abdomen and spine (all p<0.001) and an increased rate of pelvic injures with significant blood loss, blood loss from other areas or tension pneumothorax (all p<0.001). Notably, spinal cord injuries occurred more frequently in the trapped group but were still rare (0.71% of all extrications).
The authors concluded that when considering the frequency, type and severity of injuries reported here, the benefit of movement minimisation may be outweighed by the additional time taken.
Addressing the difficulties of traumatic brain injury management in out-of-hospital care
Managing traumatic brain injury (TBI) is fraught with difficulties in the out-of-hospital environment, not least because prehospital clinicians rely primarily upon clinical signs to identify patients with a raised intracranial pressure (ICP). These clinical signs, include a reduction in Glasgow Coma Scale (GCS) score, fixed dilated pupil(s) and/or Cushing's triad (hypertension, bradycardia and an irregular breathing pattern). The difficulty is that clinical criteria for the detection of a raised ICP are not well defined, such that there are no cut-off values for blood pressure and heart rate to define Cushing's response and there is no definition of ‘fixed dilated pupils’ in the context of TBI.
This retrospective cohort study investigated adult patients attended by helicopter emergency medical services (HEMS) who had sustained a TBI and required prehospital anaesthesia between January 2016 and January 2018. They sought to establish optimal cut-off values for clinical signs to identify patients with a raised ICP and to investigate the diagnostic accuracy for combinations of these values.
The bad news is that they found clinical signs to be a poor predictor of a raised ICP following TBI in the prehospital setting. Treatment decisions based on clinical signs of a raised ICP are correct in only around 75% of the cases. As part of their work, the researchers did identify the optimal cut-off values to discriminate patients with a raised ICP (systolic blood pressure &160 mmHg, heart rate <60 bpm and a fixed pupil &5 mm) but even using these criteria, the recognition of raised ICP does not improve.
Teaching has traditionally held that Cushing's response is a good indicator of raised ICP but while the Cushing's response had a high specificity of 96.9% for the detection of a raised ICP, it had a sensitivity of just 11.5%. Only seven patients in this study had a fixed dilated pupil and fulfilled Cushing's criteria
The researchers concluded that traditional clinical signs of raised ICP may under-triage patients to prehospital treatment and that further research should identify more accurate clinical signs or alternative non-invasive diagnostic aids in the prehospital environment.