Ultrasound in cardiac arrest: a feasibility study
Over the years there has been growing interest in the use of ultrasound as a diagnostic tool to enhance paramedic practice when managing patients with a variety of clinical presentations.
This study aimed to evaluate whether paramedics can be educated to carry out focused echocardiography in life support (ELS) involving the use of ultrasound scanning to assess cardiac function, as well as recognise reversible causes of cardiac arrest.
The study was undertaken in the Scottish Ambulance Service using paramedics from the Resuscitation Rapid Response Unit (3RU) who are regularly exposed to out-of-hospital cardiac arrest. Eleven of the 3RU staff attended a one-day training course focused on ELS.
They were taught to acquire both parasternal and subxiphoid views, and to assess the images for presence of movement, quality of function, recognition of rhythm, presence of fluid (i.e. pericardial effusion), and size of the chambers of the heart.
In total, nine paramedics participated in the data collection. Participants' knowledge was assessed through the use of pre- and post-course questionnaires to assess whether there was any difference in theoretical knowledge level (including interpretation) linked to participation in the educational intervention.
Additionally, after completion of the course, each paramedic was assessed on their ELS performance on three healthy volunteers. Participants had to a) perform one subxiphoid and one parasternal scan—they were assessed on time taken and quality of image; b) perform both scans in a 10-second window simulating the rhythm checks during a cardiac arrest (only if they managed this was the quality of the image assessed). Image quality was evaluated using a five-point scale with 1 being poor quality, and 5 being high quality.
Results demonstrated a significant improvement in knowledge from a mean pre-course score of 54% to a post-course score of 89% (p<0.001).
During the moulages, in relation to practical skills, all nine participants managed to produce images from both parasternal and subxiphoid views on every attempt. For the parasternal view the mean time taken to acquire an image was 13.1 seconds and the mean image quality was 4.1. For the subxiphoid view, mean time was 13.2 seconds with a mean image quality of 3.8.
During simulated resuscitation, in both views the success rate was 88% of images attained within the 10-second time frame, with a mean image quality of 3.8 in the subxiphoid view, and 4.0 in the parasternal view.
Ten weeks after the course, four participants were re-assessed involving a repeat questionnaire and another practical assessment. Three participants acquired a subxiphoid image (mean quality 3) and one achieved a parasternal view (image quality 4). Theoretical knowledge was reduced (82%; p=0.13), and this was deemed as non-significant; however, it is not possible to draw any firm conclusions from such a small sub-group.
The authors recognise that their study has limitations—for example, the small sample size and the use of a specific cohort of paramedics who are exposed to a high number of cardiac arrests (which prohibits generalisation of the results). Additionally, the participants were scanning healthy volunteers in a controlled environment, which does not accurately reflect the nature of the out-of-hospital environment.
In conclusion, although this is a small-scale feasibility study, the results demonstrate that paramedics can be trained to perform ELS. However, before implementing this practice across all Trusts, there is a need for larger studies to be undertaken involving non-specialist paramedics to establish whether these findings can be repeated. In addition, the authors recommend that future research should focus on establishing whether ELS actually contributes in a meaningful way to paramedics' clinical decision-making about management of patients in cardiac arrest in the pre-hospital setting.
Managing pain associated with femoral fractures: an alternative approach?
This study set out to examine both the feasibility and efficacy of paramedic-performed fascia iliaca compartment block (FICB) on patients with suspected femoral fractures compared to using only morphine to control the patients' pain.
Undertaken in New South Wales in Australia, between July 2010 and July 2011, this randomised control trial involved intensive care paramedics (trained in advanced life support and non-drug facilitated intubation) who had participated in a self-directed learning programme on regional anaesthesia plus one attendance day with a specialist in anaesthesia.
The primary outcome measure for this research was a change in the verbal numerical pain scale (VNPS) between the first measurement (as soon as possible after paramedics arrived on scene) and a second measurement taken 15 minutes after either the first administration of morphine sulphate (control group), or the administration of local anaesthetic (intervention group).
Secondary outcomes included: differences in VPNS on arrival at hospital (paramedic assessment), at the point of triage (independent assessment by triage nurse), on transfer from stretcher to bed in the emergency department (ED); and assessment after two hours (ED staff); patient satisfaction scores; number and type of adverse events; and assessment of the quality of the block in relation to the patients' responses to a cold stimulus.
In total, 25 patients were included in the study with 12 randomised to receive FCIB (one was subsequently excluded as the paramedic was unable to find the anatomical landmarks), and 13 to ‘standard’ care. Unfortunately the low numbers resulted in the study being underpowered, as sample size calculations indicated the need for a minimum of 30 patients in each group (80% power, alpha 5%).
All patients received an initial loading dose of morphine sulphate (0.1 mg/kg IV). Those in the intervention group subsequently received no further morphine sulphate before assessment of the primary outcome measure, which was evaluated 15 minutes after the injection of the local anaesthetic (lidocaine and adrenaline with an adjusted dose according to patient's estimated body weight). Patients in the standard care group were administered additional morphine sulphate as required. Any patients who were still in pain after assessment of the primary outcome were given further aliquots of morphine sulphate (2.5 mg every 2 minutes) until pain was controlled (max dose 0.5 mg/kg).
In relation to the primary outcome measure, results indicated that patients treated with FICB experienced a greater reduction in pain than the control group (median pain score 50% intervention group, and 22% control, p=0.025).
There was no difference in median pain score between the two groups on arrival at the ED or at the point of independent triage, which the authors suggest may be due to the fact that people in the control group continued to receive additional analgesia (morphine), whereas those having FICB did not.
Interestingly, when assessed at the point of transfer from stretcher to hospital bed, participants in the control group (morphine only) had higher median pain scores than those in the intervention group—the researchers infer this may be because the pain can be well managed when at rest but it is harder to control on movement, whereas a local block would consistently alleviate pain whether moving or not.
At the 2-hour assessment point, those who had received FICB had lower pain scores, although this difference did not reach the point of statistical significance.
Notably there was no difference between the groups in relation to on-scene time, despite the FICB procedure taking between 8–15 minutes (median time 11 minutes).
When being tested for sensory reaction using an icepack as a cold stimulus, five participants had complete sensory blockade; four had partial, and two experienced no reduction in cold sensation.
In relation to patient satisfaction there was no difference between the two groups, with no one reporting poor pain control, although one patient in the FICB group rated the control as average.
There were no significant adverse effects observed in the intervention group, whereas in the control group (morphine) there were reported events including nausea (38%).
There are limitations with this study, including the issue of sample size discussed earlier. Using a loading dose of morphine for all patients potentially impacts on the results as it is more difficult to demonstrate a difference between the two groups, but this was a condition of the ethical approval for the study as the feasibility of paramedic-performed FICB was unknown at the start of this research and therefore the ethics board needed reassurance that no patient would suffer uncontrolled pain as a direct result of the trial. The authors recommend that as this study has demonstrated that paramedics can perform FICB, future studies could omit the loading dose in the FICB group and should include a longer period of follow up. Another consideration is that the study was restricted to a specialist sub-set of paramedics and therefore may not be generalisable to other non-specialist paramedics.
‘Paramedic-performed FICB could be a useful option in the management of pain in patients who have sustained a femoral fracture’
Although FICB is currently not applicable to UK paramedic practice, it is interesting to look at a wider picture of urgent, unscheduled care to examine whether paramedic practice in other countries could influence UK practice if the conditions were right. The authors of this paper suggest that paramedic-performed FICB could be a useful option in the management of pain in patients who have sustained a femoral fracture, but further research on a larger scale is required to evaluate the full impact of this procedure on patient safety and pain management.