Femoral neck fractures are one of the most common limb injuries encountered in the pre-hospital setting and affect up to 75 000 elderly people each year (British Orthopaedic Association, 2007). Despite being a common injury, it should not be underestimated; 10% of people with these fractures die within 1 month and up to a third within 12 months (National Clinical Guideline Centre, 2010).
While the majority of these deaths are attributed to co-morbidities (such as pneumonia), effective management from the start of the injury is likely to reduce mortality. A key component of this management surrounds the pharmacological interventions paramedics can offer, particularly to combat pain and prepare the patient for surgery. This article focuses upon pain management in the pre-hospital setting, specifically related to management of femoral neck fracture. The need for a competent assessment of this injury (including a pain assessment) is recognised but is beyond the remit of this article.
What is a femoral neck fracture?
The femoral head and neck lie within the joint capsule of the hip joint, and the head of the femur moves within the acetabulum. The most common site of fracture is within the intracapsular region, largely as a result of the periosteum being very thin and increasingly diminished around the femur (Dolan and Holt, 2008).
Garden’s (1964) classification of femoral neck fractures is still widely used by physicians and describes four stages of fracture; Stage I represents impacted fractures, Stage II demonstrates non displaced fractures, Stage III depicts displaced fractures and Stage IV portrays displaced and adducted fractures (Figure 2). While these different types of fractures may seem to have little implication for emergency assessment and management, it is important for the pre-hospital clinician to understand that there are differing types of femoral neck fractures to ensure that a full patient assessment is carried out (Dolan and Holt, 2008). While shortening and rotation are often the cardinal signs of femoral neck fractures, it is only prevalent with a stage IV fracture, so the absence of this sign does not eliminate the risk of a fracture to the femoral neck. The other three types of fracture are unlikely to present with these cardinal signs, even though a fracture to the femoral head has occurred. For this reason, a full assessment should be carried out on any patient with a suspected fracture to the femoral neck.
Why do they occur?
The majority of femoral neck fractures occur in female patients aged over 80 years (Parker and Johansen, 2006). The usual mechanism of injury is minor or indirect trauma, although many other factors contribute to the problem (Eiff et al, 1998). These factors include the increased tendency for elderly people to fall, reduced bone strength and osteoporosis (particularly in women), and a loss of protective reflexes when falling—meaning falls tend to be on the hip and thus the already weak femoral neck becomes fractured (Parker and Johansen, 2006).
Pre-hospital assessment
All pre-hospital assessments should follow the systematic ABCDE approach to eliminate life threatening presentations. In suspected femoral neck fractures it is important to ascertain the underlying reasons for the fall: whether it is mechanical (due to stumbling) or medical. It is for this reason that a cardiac and metabolic assessment should take place to include blood pressure, a 12 lead electrocardiogram and a blood glucose reading (Greaves and Porter, 2010).
A formal assessment of pain status should also be carried out in order to facilitate appropriate patient management (Gloth, 2004). This should include a thorough assessment of the pain and include one of three common pain rating scales: the visual analogue scale or the verbal rating scale or the numerical rating scale. Williamson and Hoggart (2005) outline that the numerical rating scale often provides the most sensitive data, but patients’ often prefer a verbal rating scale—though this can be misunderstood. With this in mind, a combination of these scales may be appropriate, particularly considering the various co-morbidities of the elderly (including deafness or dementia).
Examination for musculoskeletal injuries should follow the ‘look, feel and move’ principles of assessment, although this is unnecessary in the presence of obvious fractures and should be ceased if it will produce further pain (Greaves and Porter, 2010). In the ‘move’ element of this assessment, the clinician should assess whether the patient can perform a straight leg raise (hip flexion) and flex the knee. Except for minor (incomplete) fractures, patients with any fracture to this region will be unable to perform a straight leg raise (Greaves and Porter, 2010). However, it should be remembered that patients with generally poor mobility or osteoarthritis may also have difficulty in moving their leg in this manner. By questioning the patient about any new pain or a new reduction in their mobility, the indication of a new fracture may be sought.
Hydration status should also be assessed in the pre-hospital environment. This can be done by testing the turgor of the skin by gently squeezing the skin on the patient’s forearm and observing for the length of time it takes to return to its original shape—more than 30 seconds is considered to show dehydration (Buss, 2011). Dehydration is believed to contribute heavily to mortality rates following hospital treatment, which will be discussed further (McRae and Esser, 2002; Sutcliffe 2006; Dolan and Holt, 2008).
Clinical symptoms and signs
As there are four types of femoral neck fracture, not all fractures will show shortening and rotation, and more atypical presentations do exist. There are certain signs that are characteristic of fractures to this site. In the first instance, patients will often be lying in the position that they fell, unable to move due to pain, which may be in the groin and through the thigh to the knee. Except for minor (incomplete) fractures, patients with any fracture to this region will be unable to perform a straight leg raise (Greaves and Porter, 2010).
In stage IV fractures, the leg may appear to be externally rotated and slightly adducted as displacement has occurred at the fracture site. With all types of this fracture, pain is often worsened on movement and patients are usually unable to bear weight following the injury (Crawford-Adams and Hamblen, 1999; Gates and Mooar, 1999; Greaves and Porter, 2010). Clinicians should remember that there are a range of pain experiences; although a fracture to the femoral head is regarded as a painful condition, some patients may not complain of pain at all. Therefore, any suspected fracture should be fully exposed and evaluated, and clinicians should not rely on looking for deformity or areas of pain alone (Vassiliadis, 2002).
Pre-hospital management–pain relief
Pain relief is regarded as an ethical human right, set out by The International Covenant on Economic, Social and Cultural Rights (The Office of the United Nations High Commissioner for Human Rights, 1966). This pronounces the right ‘of everyone to the enjoyment of the highest attainable standard of physical and mental health’.
Thus, there is a strong argument for an individual’s right to pain relief from the expressed right to health. Untreated pain can not only produce psychological stress and anxiety, but also produces a neuro-humoral response (Dunwoody et al, 2008). This increases the sympathetic response, resulting in increased tachycardia, elevated blood pressure and increased oxygen consumption (Liu and Gropper, 2003), and poor wound healing (Kopf and Patel, 2010). For both ethical and physiological reasons, paramedics should seek to give pain relief to any patient complaining of pain.
To provide optimal pain relief, a comprehensive pain assessment is essential, but should also be continual to ensure that the appropriate treatment is given and an adequate response maintained (Herr, 2011). Many patients with femoral neck fractures do not receive pre-hospital analgesia, despite complaining of pain, and further analgesia administration in the emergency department is influenced by whether the patient has been given pre-hospital pain relief (Kelly, 2000; Vassiliadis et al, 2002). While a conventional ladder pain assessment may be difficult to obtain in elderly patients (due to dementia or other chronic painful conditions), a combination of pain scales and a thorough history of the injury from the patient (and family where necessary) can help identify and locate any pain, which can then be treated accordingly (Williamson and Hoggart, 2005; Gregory and Ward, 2010). Fisher, Brown and Cooke (2006) advocate that suitable analgesia should be given to patients with femoral neck fractures.
In the United Kingdom, under the Joint Royal Colleges Ambulance Liaison Committee (JRCALC), paramedics are approved to administer four types of analgesics: inhalational analgesia (nitrous oxide/oxygen mix), oral analgesia (paracetamol and ibuprofen), parenteral and enteral analgesia (morphine) and topical analgesia (tetracaine, lignocaine). Individual ambulance trusts may also use patient group directives (PGDs) to provide their clinicians with a greater range of analgesic options, such as codeine, tramadol and IV (IV) paracetamol.
Entonox
Entonox is recommended for patients with lower extremity fractures (Lee and Porter, 2005; Thomas and Shewakramani, 2008). Entonox has a very low solubility in blood, which allows for rapid saturation in the brain (where it has its anaesthetic effect) and also rapid elimination; hence it does not mask any signs or symptoms that may aid a differential diagnosis (Simonsen et al, 2006). The adverse effects of entonox (including dizziness) are deemed to be outweighed by the benefits of immediate pain relief. As good pain relief from entonox is consistent across a diverse group of investigations, reliability in the combined results reinforces the applicability of this drug for musculoskeletal injuries (Faddy and Garlick, 2005; Lindsay, 2007).
While it is useful to treat a diverse group of injuries, there are potential problems related to the method of administration, especially in elderly patients. The device used to deliver entonox works on a demand valve activated by the patient’s inspired breath, however, there must be a minimum effort of 0.25 kPa (British Oxygen Company, 2010).
Peak inspiratory pressures tend to decrease due to decreased respiratory muscle force, as part of the ageing process (Tack et al, 1983). With this in mind, some elderly people who sustain femoral neck fractures may not have respiratory muscles strong enough to create the required pressure to activate the demand valve and obtain the drug. In addition, the device may need to be altered to provide optimal drug uptake. Gregory and Mursell (2010) advocate the use of a face mask rather than mouth piece for administration of this analgesic, as the face mask allows full inhalation of the drug and minimal outside air. However, it should be recognised that, as entonox should only be self administered by the patient (Fisher et al, 2006), some elderly patients may have difficulty in holding the face mask to their face in an appropriate manner. For this reason, this analgesic may not be appropriate for all elderly patients and continuous assessments need to be done by the clinician to evaluate its effectiveness.
Lee and Porter (2005) advocate the use of entonox for splinting and transfer-manoeuvres, which would take place in the pre-hospital environment. In patients who are able to activate the demand valve and are able to self administer the drug, it should be administered via a face mask to provide initial pain relief while other drug treatments are being prepared. Following the transfer of the patient to the ambulance stretcher, it is more appropriate to consider other avenues of pain relief, as the use of entonox in the elderly group can be poor and, therefore, the analgesia being provided is suboptimal.
Ibuprofen and paracetamol
Oral analgesia in the form of paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs) are not considered immediate analgesia in the treatment of lower leg injuries; trauma injuries or specific femoral neck injuries (Vassiliadis, 2002; Lee and Porter, 2005; Thomas and Shewakramani, 2008), though they may still provide effective pain relief. A search of key medical databases (Pubmed and Cinahl, 2012) revealed a paucity of recent research on this topic, possibly on ethical grounds. Both ibuprofen and paracetamol are thought to reduce pain by inhibiting the synthesis of prostaglandins, though the complete mechanism of action is not fully understood. Ibuprofen inhibits cyclooxygenase (the agent that catalyses the manufacture of prostaglandins) and also limits the inflammatory response, as well as acting on peripheral nociceptors—reducing the generation of nociceptive (pain) impulses (Simonsen et al, 2006).
By inhibiting the production of prostaglandins, acid secretion in the stomach increases as prostaglandins prevent the synthesis of hydrochloric acid in the stomach mucosa. This results in acid-related inflammation of the stomach and sometimes bleeding, which can have a profound effect on the elderly patient if taken regularly.
One study comparing ibuprofen and paracetamol in musculoskeletal pain noted that ibuprofen had a far greater effect and tolerability than paracetamol (Boureau et al, 2004). Although this focused on the elderly population, it was limited as it included only those with osteoarthritis. As well as this, the analgesic was titrated to effect over 6 hours, compared with the short duration of pre-hospital care, where only one 400 mg ibuprofen tablet could be given. While this paper showed ibuprofen to be superior to paracetamol within the first hour (Boureau et al, 2004), the benefits
‘The IV route offers an almost immediate onset of effect and can be titrated to clinical effect’
side effects (including gastrointestinal disturbance and fuid retention) in the elderly population. For this reason, even a single dose of NSAIDs are not recommended as analgesia for patients with femoral neck fractures, and paracetamol should be used instead (National Clinical Guideline Centre, 2010).
The mechanism of paracetamol is not fully understood so far, but it is thought to have a combination of a peripheral and central effect. The peripheral effect is COX-2 inhibition, which inhibits prostaglandin synthesis and has a peripheral effect on the nociceptors in a similar way to ibuprofen (Simonsen et al, 2006). Recent studies suggest it is also has a central effect that first reinforces the activity of endogenous opioid and/or cannabinoid systems in the brain. From here it is also thought to reinforce the effect on the descending serotonergic pathways and spinal 5-HT7 receptors to reduce sensitivity to pain stimuli (Dogrul et al, 2012). The National Clinical Guideline Centre (2010) advocates paracetamol as a safe drug to use, largely due to the diminished risk of gastrointestinal bleeding. Therefore, paracetamol is deemed an effective analgesic and can be used either singularly or alongside other analgesia in the pre-hospital management of femoral neck fractures. However, one major limitation of giving repeated doses of oral paracetamol is the limit in its analgesic efficacy—once the maximum dose has been given, and the patient is still complaining of pain, further doses will have no further effect and a toxic level may be reached once the patient is in hospital (Hawthorn and Redmond, 1999; Parsons and Preece, 2010). For this reason, a combination of analgesia may be required.
Some ambulance trusts use PGDs to maximise the pain relief available for their patients. Two common PGDs are for oral codeine phosphate and tramadol, both weak opioids. Tramadol has long been used to treat musculoskeletal pain and there is evidence to show that it has a strong analgesic efficacy after the initial dose (Pagliara et al, 1997), but is often only available to ambulance nurses or emergency care practitioners. Codeine phosphate is also shown to be effective for the treatment of musculoskeletal pain, but the elderly patient is more likely to experience adverse effects, such as dizziness, vomiting or constipation, than with tramadol (Gloth, 2004). It is worth noting that codeine is a ‘pro-drug’ converted to morphine inside the stomach in phase 1 metabolism (McGavock, 2010). Codeine reaches its maximum analgesic effect when administered alongside paracetamol and, for this reason, should be considered alongside paracetamol as the first course of treatment for any musculoskeletal injury (Moore et al, 1997).
However, there are limitations in administering any oral analgesic to patients in severe pain. The time to optimal pain relief using the oral route is at least 20 minutes (Simonsen et al, 2006) and patients in severe pain have a delayed gastric absorption rate (Dunwoody et al, 2008), thus prolonging optimal analgesic effects. In addition, patients who have sustained this fracture are often lying on the foor, and will remain lying down for immobilisation and transfer, they may be unable to physically swallow a tablet. While this should not be a deterrent for administering oral analgesics, the patient’s severity of pain should be thoroughly assessed and more prompt pain relief may need to be considered.
Morphine
The National Clinical Guideline Centre (2010) advocates offering opioids if paracetamol alone does not provide sufficient relief. Morphine works centrally in the midbrain nuclei and cerebral cortex. It stimulates the release of 5-HT noradrenalin and enkephalins, which directly inhibit the spinal dorsal horn and further inhibit the peripheral terminals of the pain fbres. In this way, it inhibits pain signals both centrally and peripherally.
There are three opioid receptors: μ (mu), δ (delta) and κ (kappa). Natural opioids (enkephalins) target all these receptors, but morphine and other opiate analgesics bind selectively to the mu receptor (McGavock, 2010). IV (IV) morphine provides very effective analgesia, which can be titrated to clinical effect and patient need, rather than giving a single dose as with oral morphine (Lee and Porter, 2005). IV morphine is the fastest working and longest lasting opioid when compared with intramuscular and oral morphine. The IV route offers an almost immediate onset of effect and can be titrated to clinical effect (rather than block administration with intramuscular (IM) and oral morphine); and has a duration of up to 4 hours (Thomas and Shewakramani, 2008).
While it is believed that elderly patients are more susceptible to the adverse effects of opioid analgesics (National Clinical Guideline Centre, 2010), lower doses of morphine at 0.05 mg/kg are inappropriate for treating severe pain, and higher doses starting at 0.1 mg/kg are found to be effective for use in the pre-hospital setting (Bounes et al, 2008).
The average weight of an 80-year-old female (the age and sex where femoral neck fractures are most common) is approximately 60 kg. Therefore under this guidance, 6 mg of morphine should be the initial dose for severe pain in this age group. This is in contrast to current guidelines, which advocate only 2.5 mg for elderly patients over 65, possibly due to the potential side effects (Fisher et al, 2006). Therefore, the paramedic needs to create a balance between these two doses: a dose not so low as to inadequately treat pain, but not so high that the potential side effects (including respiratory depression and nausea) outweigh the benefits.
It is this weight-dose link that presents the problem with the administration of intramuscular (IM) or oral morphine, as block administration may not treat the pain at all or intensify these side effects. The rate of absorption of IM morphine is dependent on muscle mass, tissue perfusion and dehydration (McGavock, 2010). Oral morphine is again dependent on gastric motility, which is reduced in severe pain (Dunwoody et al, 2008). However, since the analgesic efficacy of IM and oral morphine is arguably less than IV administration (Thomas and Shewakramani, 2008), it could be argued that this block administration does not present a problem regarding adverse effects, but may not provide adequate pain relief. Problems regarding the patient lying down may mean oral morphine is contraindicated due to risk of choking (Fisher, Brown and Cooke, 2006) or a loss of muscle mass in the elderly patient may make intramuscular injection more challenging. The pre-hospital clinician needs to use their autonomy to decide on the most appropriate route of morphine for each individual patient.
While morphine is currently the most widely available IV opioid that can be administered by paramedics (Medicines and Healthcare Products Regulatory Agency, 2011), other opioids may be effective in reducing pain in the pre-hospital environment. In a comparison of intranasal fentanyl and IV morphine, there was no statistical difference in pain reduction from the baseline value to that obtained at hospital, demonstrating that these different opioids were not significantly different in their pre-hospital effectiveness (Rickard et al, 2007). Similar results were found by Galinski et al (2005) comparing the IV routes of administration for fentanyl and morphine. Intranasal fentanyl was easier to administer due to the accessible intranasal route, and had a rapid effect due to the quick absorption rate. This is in contrast to the IV route, where some patients are unable to be cannulated and others refuse treatment due to needle phobia. However, fentanyl is a fat soluble opioid. This allows it to have a quick absorption rate, but also has a half life of 15 minutes. This is comparable to IV morphine, which has a slightly slower onset (being a water soluble opioid), but a half life of 200 minutes (McGavock, 2010). With this in mind, the intranasal route would be ideal in a patient in whom IV access is difficult but fentanyl may not be the most suitable opioid in the treatment of a femoral neck fracture, where a longer lasting analgesic would be more appropriate.
Another study has found comparable results between IV morphine and IV paracetamol (Craig et al, 2012). A considerable limitation of this study was that morphine was not titrated to effect, despite it being advocated to be best method of administration in the elderly (Lee and Porter, 2005; Bhangu et al, 2010; The National Clinical Guideline Centre, 2010). The study has highlighted that block use of IV paracetamol can prove advantageous for both patient and clinician (Craig et al, 2012). Despite this, there is still little pre-hospital research relating to the use of IV paracetamol alone. One PGD advocates that IV paracetamol infusion is used for the treatment of severe pain as an alternative to IV morphine, or when morphine is providing insufficient analgesia (England, 2012). This indicates that IV paracetamol infusion is suitable for patients with a femoral neck fracture, though only in the ambulance trust where this particular PGD is applicable. While Craig et al (2012) suggest that IV paracetamol provides effective pain relief in musculoskeletal injuries, we await the publication
‘Pain relief for femoral neck fractures should be considered in a step-wise approach’
As a final point, pain relief for femoral neck fractures should be considered in a step-wise approach. This should ideally start at entonox, progress towards oral paracetamol and additionally morphine. If PGDs to provide further pain relief, such as tramadol, codeine or IV paracetamol are active within the paramedics’ trust, these further analgesics should be incorporated into this step-wise approach. The paramedic should assess patient status and use their clinical judgement to determine the type and route of analgesic to ensure the patient remains pain free throughout (The National Clinical Guideline Centre, 2010). Currently, IV morphine appears to be the best form of analgesia that can be given to elderly patients by all paramedics, providing it has an initial higher dose and is titrated to clinical effect (Lee and Porter, 2005; Bounes et al, 2008; The National Clinical Guideline Centre, 2010).
Pre-hospital management–fluid rehydration
Dehydration is associated with increased mortality following femoral neck fracture and the use of IV crystalloids prior to surgery is advocated (McRae and Esser, 2002, Sutcliffe; 2006). The principle goal of fuid administration is to maintain tissue perfusion (through hydration status) and compensate for fluid loses during surgery (Arkilic et al, 2003; Chong et al, 2009). Inadequate fluid resuscitation can lead to organ failure, due to decreased intravascular volume and inadequate interstitial perfusion—affecting cardiac, pulmonary, renal and gastrointestinal systems (Chong et al, 2009). However, excessive fluid resuscitation may lead to cardiac failure, resulting in complications following surgery and poor survival rates (Venn et al, 2002; Brandstrup et al, 2003). Nevertheless, fluid administration before and during surgery shortens the time to being medically fit for discharge and is an intervention that can be started in the pre-hospital setting (Venn et al, 2002).
However, a majority of this research focuses on fluid administration before, during and following surgery, with a deficiency in pre-hospital evidence. Fisher, Brown and Cooke (2006) advocate both sodium chloride and sodium lactate with a loading volume of 250 ml to reverse dehydration and improve tissue perfusion. IV fluids are generally advocated for initial replacement in the pre-hospital arena if dehydration is detected or if there is a prolonged journey time to hospital or transfer to a hospital bed, as it is a basic resuscitative manoeuvre (Bhangu et al, 2010; Greaves and Porter, 2010).
Pre-hospital management–immobilisation
The application of a splint is deemed essential in reducing pain. Principles of immobilisation include continual reassessment of the neurovascular status prior to and following the immobilisation of the joints above and below the fracture (Lee and Porter, 2005). As the femoral neck is within the pelvis (and so cannot be easily splinted above the fracture site), the whole leg is immobilised to reduce movement and so prevent pain.
Following the administration of appropriate analgesia, the leg should be repositioned (if required) and secured to the uninjured leg (Greaves and Porter, 2010). Figure 4 shows the appropriate way to splint a suspected femoral neck fracture. There should be padding between the legs, using either an ambulance service blanket or multiple triangular bandages. Broad bandages should be used above and below the knee, splinting the injured leg to the good leg. A figure of eight knot around the ankles will prevent further movement of the injured leg, helping to reduce further pain (Lee and Porter, 2005).
Nevertheless, there are some limitations with this type of splinting. Although the injured leg is secured to the good leg, there is still a possibility of movement from the hips–causing further pain and possibly worsening the fracture, depending on severity. As this injury is often due to a fall (Eiff et al, 1998), these patients will also require lifting onto a stretcher and moving into the ambulance.
The use of carry or striker chairs to convey patients with these injuries should be avoided. Not only will movement (and so pain) be magnified during transfer, further injury to surrounding tissue may also occur due to impaction of the injury. A scoop stretcher is the most appropriate type of lifting aid, as it reduces the need to log roll the patient and so prevents any further movement which may cause damage (Krell et al, 2007). However, in practice, scoop stretchers can be difficult to use if patients need to be manoeuvred down stairs or where there are other space restrictions. In addition, lying down flat may aggravate other chronic conditions the patient may have (such as respiratory diffculties) and may initiate the development of pressure sores–which could be further exacerbated in hospital. While the scoop stretcher is deemed the best and safest method for removal of the patient, the clinician needs to weigh up each situation individually to ensure the most appropriate aid for removal is used to reduce pain, reduce impaction of the fracture and to promote tissue viability.
Conclusion
As fractures to the femoral neck are so common, there is a need for paramedics to be able to recognise both the cardinal signs and atypical features of these fractures and provide the highest level of care to reduce morbidity and mortality. Alongside this recognition should be investigations to discover the reason for the fracture, to reduce other co-morbidities (Parker and Johansen, 2006; Greaves and Porter, 2010). Pain relief should be instigated early, ideally in a step-wise approach using entonox and oral paracetamol. However, bearing in mind the slow mechanism of onset for paracetamol, the paramedic should use their clinical judgement to assess the status of the patient and consider the immediate administration of IV morphine in conjunction with ambulance service guidelines (Fisher et al, 2006; National Clinical Guideline Centre, 2010). Secondary to pain relief, hydration status should be assessed to prepare the patient for surgery (McRae and Esser, 2002) and fluid replacement should be commenced if the patient appears dehydrated or if journey time to hospital is prolonged (Greaves and Porter, 2010).
Immobilisation of the injured leg and transfering using the scoop stretcher not only reduces further pain but also provides a safe means of transferring the patient to the ambulance and prevents further damage to the leg (Lee and Porter, 2005). This pre-hospital management of the patient with a femoral neck fracture ensures the patient will receive the highest levels of care in the scope of practice of a paramedic by providing adequate analgesia and fluid replacement before any definitive treatment at hospital.
