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Emerg Med J 30:501-505 doi:10.1136/emermed-2012-202291
  • Prehospital care

The use of analgesia in mountain rescue casualties with moderate or severe pain

  1. Peter Paal3
  1. 1Birbeck Medical Group, Penrith Health Centre, Penrith, Cumbria, UK
  2. 2Department of Emergency Medicine, West Cumberland Hospital, Whitehaven, Cumbria, UK
  3. 3Department of Anesthesiology and Critical Care Medicine, Innsbruck Medical University, Innsbruck, Austria
  1. Correspondence to Dr John Ellerton, Birbeck Medical Group, Penrith Health Centre, Bridge Lane, Penrith, Cumbria CA11 8HW, UK; johnellerton01{at}btinternet.com
  • Received 16 December 2012
  • Revised 16 January 2013
  • Accepted 17 January 2013
  • Published Online First 12 February 2013

Abstract

Objectives To assess the effectiveness of analgesia used in mountain rescue (MR) in casualties with moderate or severe pain. To determine if a verbal numeric pain score is practical in this environment. To describe the analgesic strategies used by MR.

Design Prospective, descriptive study.

Setting Fifty-one MR teams in England and Wales. The study period was 1 September 2008 to 31 August 2010.

Participants 92 MR casualties with a pain scoreof 4/10 or greater.

Main outcome 38% of casualties achieved a pain reduction of 50% or greater in their initial score at 15 min and 60.2% had achieved this at handover.

Results The initial pain score was 8 (median), reducing to 5 at 15 min and 3 at handover. The mean pain reduction was 2.5±2.4 at 15 min and 3.9±2.5 at handover. 80 casualties (87%) were treated with an opioid and seven had two different opioids administered. Seven main strategies were identified in which the principal agent was entonox, intramuscular opioid, oral analgesia, fentanyl lozenge, intranasal or intravenous opioid. The choice of strategy varied with the skills of the casualty carer.

Conclusions Pain should be assessed using a pain score. When possible, intravenous opioid is the gold standard to achieve early and continuing pain control in patients with moderate or severe pain. Entonox and oral analgesics, as sole agents, have limited use in moderate or severe pain. Intranasal opioid and fentanyl lozenge are effective, and appropriate in MR. Research priorities include bioavailability in different environmental conditions and patient's satisfaction with their pain management.

Introduction

This is a formative evaluation that aims to gain insight into the use and effectiveness of analgesia delivered in mountain rescue (MR). MR is performed in a difficult environment, with the weather, terrain and remote locations presenting physical challenges. Operational and strategic challenges exist by virtue of its voluntary nature, multiple teams and the varying skills of the casualty carers who may arrive on scene at different times. In England and Wales, MR responds to an average of 980 incidents per year during which 511 injured or ill casualties are managed.1 Whilst most MR casualties will have traumatic injuries (78.4%), the service also responds to a wide spectrum of illness.2 Trained MR team members can provide analgesia if they hold a mountain rescue England and Wales (MREW) casualty care certificate. This allows them, through Home Office licences and an amendment in the Medicines Act, to possess and administer analgesics including strong opioids.3 Healthcare professionals, allied to teams, work within their own licence to practice. Historically, intramuscular morphine has been the mainstay for treating moderate and severe pain. However, the practicalities of accessing injection sites and the variability of absorption in some conditions (environmental and casualty specific) have led some to question its use. In addition, many team members display a reluctance to inject that may contribute to poor analgesia. As a consequence, buccal fentanyl and intranasal opioids have been introduced.

The provision of effective and safe analgesia is a core principle of prehospital care and MR, and is a clinical standard in emergency medicine.4 However, there is a paucity of literature on prehospital analgesia. Previous studies have illustrated a delay in administering analgesia and poor documentation of pain scores despite demonstrating their feasibility.5 ,6 This is the first study to report on the provision and effectiveness of analgesia in MR. There have been no previous studies demonstrating the use of pain scores to assess and guide treatment in MR.

Methods

Quantitative data are used to describe the effectiveness of pain relief by changes in an 11-point (0–10) verbal numeric rating scale (VNRS).7 Its simplicity and the ease of communicating the score by radio make the VNRS attractive. Effective analgesia was defined as 50% or greater pain reduction from the initial score.8 The overall effectiveness of analgesia was determined by averaging the percentage of casualties achieving a or greater reduction in pain score at both 15 min and handover, and then assigning a descriptive rank score (poorest, intermediate, best) to each strategy.

Descriptive data are used to identify the strategies used to treat pain. The small number of casualties, the use of multiple drugs used the high ‘placebo’ effect in acute pain trials make it inappropriate to attempt statistical comparison between the strategies.9

Data collection and handling

In each episode in which a MR casualty had a pain score of 4/10 or greater at initial assessment, a standard form was used to collect and return data (see supplementary figure 1, available online only). Members of the MREW medical subcommittee piloted the form between 1 May  and 31 August 2008 resulting in 12 completed forms. The data on 10 of these forms could be used to assess the effectiveness of analgesia and were added to this part of the analysis.

The study protocol explained that the pain score should relate to pain on movement rather that at rest because MR inevitably requires lifting and movement on rough terrain during extrication and evacuation. This is different from the hospital setting but similar to other forms of prehospital care. The pain score was recorded at time 0 (initial assessment), 15 min after giving analgesia, and at handover to another agency. The 15 min time was chosen to reflect the point at which splinting and packaging of a casualty would start. The analgesia used, dose and route were recorded from time 0 to handover. Complications or other notable events were recorded.

All forms were returned to a single researcher (JAE). The anonymous data were transcribed to an Excel spreadsheet. The mean and SD was calculated for the overall pain relief. Medians were used to quantify the effectiveness of analgesia in the subgroup analysis, as the sample size was small and the data non-parametric.

During the study period, a report was presented every 6 months to the MREW medical subcommittee as part of clinical governance; drug names were removed from this report.

In addition, the authors had access to the MREW incident database, which was independent of the study, and collects details, including drugs given, of all incidents involving MR. This database was used to assess the completeness of reporting.

Population and sample

The sampling frame was the 51 MR teams in England and Wales. They were invited to participate by way of a letter and an article in the MR newsletter. The study period was 1 September 2008 to 31 August 2010.

Results

Ninety-four forms from 17 MR teams were returned during the study period. In the same period, the MREW database recorded 209 incidents in which an analgesic drug was given. Therefore, our study captured 45% of these incidents. Comparing the study group to the MREW database, there was underreporting of parenteral opioid use (54 vs 121) and oral analgesics (11 vs 66). Conversely, fentanyl lozenge and intranasal diamorphine use (29 vs 22) were recorded more often.

Seventeen teams participated by providing at least one study form (median 4, range 1–17) including all teams attending more than 50 incidents a year. Geographical data shows the study captured most of the MR activity in three of the four regions where analgesia was used most often.

Overall analgesia effectiveness in casualties with moderate or severe pain

During the study period, analgesia effectiveness was recorded in 92 forms; two study forms were excluded—one in which the initial pain score was 3 and one in which a pain score (handover) data point was missing.

The initial pain score for all casualties was 8 (median), reducing to 5 at 15 min and 3 at handover. The mean pain reduction at 15 min was 2.5 (SD 2.4). At handover, the mean pain reduction was 3.9 (SD 2.5); 38% and 60.2% of casualties achieved a pain reduction of 50% or greater of their initial score at 15 min and handover, respectively. The median time from initial analgesia to handover was 45 min (IQR 30–72.5 min); 30% of casualties had additional pain relief after 15 min.

Use of pain score

Only one data point was missing in the study forms. The reason for the omission was ‘forgot to ask’.

Analgesia strategies

The 92 casualties with moderate or severe pain received a total of 205 drugs, of which 157 were analgesics. The number of drugs given to each casualty is displayed in figure 1. Eighty of the 92 casualties (87%) were treated with an opioid; 73 received one opioid (two by different routes of administration) and seven had two different opioids administered. Thirty-nine of 92 (42%) received an antiemetic (buccal prochlorperazine, intravenous ondansetron, intravenous or intramuscular cyclisine, intravenous metoclopropramide). Other drugs administered were midazolam (four cases), inhaled methoxyflurane (three), ketamine (one) and glyceral trinitrate (one). (Methoxyflurane is an unlicensed drug in Europe although used extensively in Australasia. Its use (as Penthrox) is limited to one practitioner (JAE) while awaiting European studies such as that at Nottingham University Hospital (EudraCT no: 2011-000338-12). Five casualties had a period of ‘procedural sedation’ for manipulation. In six cases, it was commented that intravenous access had failed or had required multiple attempts. Six casualties had taken analgesia before the arrival of the rescue team.

Figure 1

Total number of drugs given to a casualty (n=92).

Seven main strategies were identified by the principal analgesic. They were: entonox, intramuscular opioid, oral analgesia, fentanyl lozenge, intranasal opioid or intravenous opioid. When multiple drugs were given, the hierarchy opioid–oral analgesia–entonox was used to place the form in the highest group. Eight forms could not be allocated and were analysed as an ‘unclassified’ group (two no drug given; two procedural sedation (midazolam, ketamine); two entonox then intravenous opioid for over 15 min; two fentanyl lozenge and intravenous opioid within 15 min). Ten forms from the pilot phase were added to the analysis.

The choice of strategy varied with the skills of the carer (table 1). Healthcare professionals, able to cannulate, tended to do so and gave intravenous opioid, whereas team members used the intramuscular and intranasal routes.

Table 1

Analgesia strategy based on skills of casualty carer (study and pilot phases)

The results for the analgesia strategy groups are summarised in table 2 and figure 2.

Table 2

Analgesia effectiveness according to strategy (study and pilot phases)

Figure 2

Analgesia effectiveness at 15 min and handover according to strategy (study and pilot phases). IM, intramuscular; IN, intranasal; IV, intravenous.

Discussion

The study reports on 45% of the MR analgesia practice in England and Wales. The reasons for non-reporting are unknown. Some of the drugs used would be for casualties with an initial pain score of less than 4/10, which were not captured in the study design. Assessing the severity of pain using a scale is new to MR, and its introduction in the study may have been an unwelcomed intrusion, particularly for teams using the well-established intramuscular morphine strategy. Teams may also have perceived that the study, and pain scoring, was for the more recent methods of analgesia, as the teaching often went hand in hand. Despite this, we conclude that the study is a reasonable representation of analgesia as practised by MREW during a transition period when newer techniques, such as fentanyl lozenge and intranasal opioid, were being introduced.

The inadequacies in the provision and effectiveness of prehospital analgesia have previously been described.4 Comparing our results with other emergency services is difficult due to differences in populations, methodology and outcome measures (table 3). Our results show a mean pain score reduction of 2.5 at 15 min; this is greater than that demonstrated in an Australian ambulance service using a mixture of strategies, but less that that achieved on the battlefield when using fentanyl lozenges.10 ,11 Our mean reduction in pain score of 3.9 at handover compares favourably with other studies, which had a range between 2.3 and 5.4.12–17

Table 3

Selected prehospital studies reporting analgesia effectiveness

Given the range of drugs, the techniques and skill sets employed, we conclude that MREW is providing reasonable pain relief. Research into patient satisfaction is urgently needed in MR.18

The VNRS was found to be a practical and feasible pain scoring method even in the harsh environment of MR. Indeed, it opened a dialogue with the casualty on their pain, with repetitive use guiding further pain management. However, it is apparent that the casualty carer does need to display a degree of flexibility not conveyed in the simple question ‘if 0 is no pain and 10 is the worst pain imaginable, what number would you give your pain?’ Having been immobile for a number of hours in a harsh environment, the casualty often responded ‘3’ despite a lower leg fracture. Unfortunately, rescue inevitably involves more movement than occurs when the casualty is in an ambulance or emergency department, and this needs to be conveyed to the casualty and anticipated by the casualty carer. Despite this reservation, we recommend that pain scoring becomes part of the current casualty care training programme.

This study demonstrates that a variety of analgesics are used in MR. Only 19/92 (21%) casualties received one drug; 87% received opioids, with seven of 92 (8%) receiving two opioid drugs. Forty-two per cent of the casualties were given an antiemetic to combat potential nausea and vomiting from the opioid and/or motion sickness during evacuation; vomiting is particularly unwanted in a casualty restrained on a MR stretcher. Reasons for polypharmacy include: failure of initial strategy to provide analgesia; a stepwise approach during the assessment and treatment with (characteristically) the use of inhalational agents followed by parenteral opioids; team members with different skill levels arriving on scene; and healthcare professionals from other agencies administering analgesics during the evacuation. In a few instances there appears to be a true multimodal strategy. Although polypharmacy is appealing and common practice in hospitals, there are very few prehospital data to inform on its advantages and disadvantages. Synergy between drugs seems likely, despite conflicting reports in the literature. For example, there was no benefit from adding methoxyflurane to intranasal fentanyl, yet co-administering morphine and ketamine was advantageous, albeit with more minor adverse effects.16 ,19 MR, with its diverse environments, injury and illnesses, and practitioners, does not lend itself to a protocol-driven approach. Both healthcare professional and non-healthcare professional casualty carers are often high achievers and independent. Combined with the ability to utilise the whole pharmacopaeia, in contrast to UK paramedics, the methods of achieving analgesia in MR has become diverse, locally determined and flexible. However, policymakers need to ensure that recommended drugs are at least compatible and acceptable to other emergency medical services.

Entonox is readily available to MR and is recommended for prehospital analgesia.20 However, the strategy of its sole use, even at 15 min, resulted in the poorest pain score reduction. A study in children has reported poor reductions in pain scores during painful procedures, although rates of satisfaction were high.21 The authors concluded that ‘N2O alone may not be the ideal drug in very painful procedures’ but remained useful for the less painful procedures as an anxiolytic. Using closed circuit systems and higher concentrations of nitrous oxide are impractical in MR; indeed, the weight and expense of the current apparatus as well as the potential for the separation of the component gases at cold temperatures makes other inhalational options, such as methoxyflurane, attractive.22

Intramuscular morphine was the most frequent technique when a non-healthcare professional administered analgesia. A medically qualified doctor attends only 20% of incidents and this route has historically provided trained team members with a potent parenteral analgesic. An intramuscular opioid produced an intermediate level of effectiveness, suggesting that it retains a place in MR if more acceptable methods are unavailable.

A strategy of using intravenous opioid is effective in producing analgesia both quickly and throughout the evacuation. This is no surprise as it has been demonstrated in other challenging settings.13 A training programme has allowed a few team members to acquire the necessary skills, but they were only able to apply their skills three times in 2 years. Focussing resources too much on this strategy may lead to an unintentional failure to deliver adequate analgesia if other effective techniques are neglected.

Intranasal opioid was introduced to MR in 2008 as an alternative method of delivery.23 The MREW protocol specifies 5 mg of diamorphine given via an atomiser, and repeated at 15 min if necessary (see supplementary figure 2, available online only). The technical and practical barriers are less than intravenous opioid while theoretically maintaining similar pharmacokinetics. Both team members and healthcare professionals used this method of delivery. Intranasal opioid was ranked as intermediate in efficacy, indicating that it has potential to provide quality analgesia in the MR setting. Seven of 18 casualties given 5 mg intranasal diamorphine required additional doses (5–10 mg) shortly after the first. Further work is needed on the bioavailability at different ambient temperatures.

Fentanyl lozenges were also introduced to MR in 2008.11 An equivalence with intravenous morphine just by unwrapping the lozenge was attractive! A MREW protocol was designed using a 800 μg lozenge, which could be repeated if necessary at 15 min (see supplementary figure 3, available online only). Team members took up this option and its effectiveness particularly by handover was good. Another study has mirrored the slower onset in action that we observed at 15 min.24

Our study captured only a small percentage of MR oral analgesia use, as the MREW database indicates that oral medication comprises two-thirds of all drugs administered. Single agents and combinations of paracetamol, codeine and diclofenac were used in casualties, many of whom, we surmise, had mild pain. For the management of moderate and severe pain, oral analgesia was ranked as poor in our study group.

Adverse events

No serious adverse events or naloxone administration were recorded. One intervention was required in a casualty with a 90° angulated fractured tibia and moderate hypothermia. The patient became hypotensive, requiring a 250 ml fluid bolus, following a difficult technical extrication having received 800 μg fentanyl lozenge, 10 mg intravenous morphine, entonox and buccal prochlorperazine 6 mg over 20 min. Other events included a fentanyl lozenge used the wrong way round (no drug administered) and a casualty that failed to respond to intranasal diamorphine who was later identified as having four MR over 6 years for a (recurrent) dislocated shoulder in different parts of the country.

Limitations

This study provides insight into patient care under challenging conditions and within a complex organisational framework. The effects of non-pharmacological methods of pain relief, such as splinting, reassurance and distraction, were not recorded. Techniques that are used rarely in special instances, such as local and regional anaesthesia, did not feature in the study period. The management of mild pain in MR has not been studied.

The use of pain scoring and the development of options other than intramuscular morphine may have contributed to the quality of analgesia. The interventions, which preceded the study, included training and protocols for more recently introduced techniques, and mirror those that improve analgesic provision.25

Team members can only give doses by protocol and this may have resulted in some loss of effectiveness both in achieving initial pain relief and in the longer term at handover. This may be particularly true in the intranasal opioid group; healthcare professionals were not restrained by protocol.

An outcome measure for effective analgesia in the prehospital environment has not been consistently defined in the literature. We chose a 50% or greater reduction from the initial pain score as a clinical outcome measure, which we believe best represents what we wish to achieve for patient care.

Conclusions and recommendations

All patients with moderate or severe pain should have their pain assessed using a pain score. The effectiveness of pain management should be reassessed and suitable interventions taken to achieve pain control during evacuation.

When possible, intravenous opioid is the gold standard to achieve early and continuing pain control in casualties with moderate or severe pain. Entonox and oral analgesics, as sole agents, have limited use in moderate or severe pain, and should be replaced by other strategies. The use of intranasal opioid is feasible and effective and should be used more extensively. Further work on the bioavailability of intranasal opioids in the MR environment should be undertaken. Fentanyl lozenges provide effective analgesia and may be an appropriate choice. The use of different modes of delivery as an option deserves further research in other prehospital settings.

Footnotes

  • Contributors All authors contributed substantially to the conception and design, acquisition of data or analysis, and interpretation of data. All authors were substantially involved in drafting the article and revising it critically for important intellectual content. All authors gave approval that the final revision be submitted. JAE is responsible for the overall content as guarantor.

  • Competing interests None.

  • Ethics approval This study observed current practice and did not require change in practice or new intervention.

  • Provenance and peer review Not commissioned; externally peer reviewed.

References


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