Chapter 11 Primary care management of acute whiplash injury

Primary care practitioners are often the first healthcare contact for individuals who have sustained a whiplash injury. While somewhat dependent upon jurisdictions, injured individuals may see community general practitioners, community allied health practitioners, including physiotherapists, chiropractors and osteopaths among others, or visit an accident and emergency department of a hospital.

The personal and economic costs associated with whiplash associated disorders (WAD) are a significant health burden, due in most part to the numbers of individuals who develop a chronic pain condition—estimated to be approximately 50%.¹ Systematic review data indicate that most recovery following whiplash injury occurs in the first two to three months, with a general plateau in symptoms occurring after this time.² More recently, trajectory modelling analyses have been used to identify distinct recovery pathways following injury. Three recovery pathways have been identified:

1. Mild: mild or negligible pain/disability for the entire 12 months (45%)

2. Moderate: initial moderate pain/disability that decreased to mild-to-moderate levels by three months (39%)

3. Chronic–severe: severe pain/disability persisting at moderate-to-severe levels for 12 months (16%).³

Of note was the finding that, in all trajectories, the most rapid recovery occurred within the first three months post injury (see Fig 2.1). Thus, the early two-to-three month period after injury seems a crucial time frame to potentially avert the course to chronic pain development following whiplash injury. The primary care provider most commonly sees the patient at this point of time and, thus, plays a vital role in the quest to reduce chronicity associated with the whiplash condition.

Although there is considerable uncertainty about the best management approaches for acute whiplash, most guidelines recommend early return to activity, exercise and education/advice based on the evidence available at the time of their development.⁴^–⁶ It has been argued that this approach may be sufficient for those with a less severe condition but for patients with a more complex condition characterised by higher pain and disability levels and more profound physical and psychological changes, additional management strategies will be necessary.⁷

Of course, WAD grade IV ⁸ (fracture or dislocation) must be recognised, and guidelines recommend the use of the Canadian C-spine rule to decide if an X-ray is required.⁵ In this chapter, only WAD grades I to III are considered.⁸ (For a description of WAD grades see Chapter 2, Table 2.1.)

This chapter outlines the current evidence for the management of acute whiplash, particularly in the primary care setting. The implications for management in accordance with the current knowledge of the heterogeneity of the whiplash condition, in terms of both physical and psychological features, as well as future treatment directions, are discussed.

Current evidence for the management of acute WAD

A recent Cochrane review of conservative management for WAD included 21 studies, evaluating a broad variety of conservative treatment approaches for acute and subacute whiplash.⁹ Interventions were divided into passive interventions (e.g. rest, immobilisation, ultrasound) and active interventions (e.g. exercises, act as usual approach), and were compared with no treatment, a placebo or each other. Only eight studies were deemed to be of a high quality. The authors reported that data pooling was not possible due to clinical and statistical heterogeneity and that, while individual studies demonstrated the effectiveness of one treatment over another, the comparisons were varied and the results inconsistent. Their conclusions were that the evidence neither supports nor refutes the effectiveness of either passive or active treatments to relieve the symptoms of WAD, grades I or II.⁹

A frequent criticism of Cochrane reviews and other systematic reviews is that, in spite of their methodological rigor, they fail to provide clear clinical answers, or lack appropriate translation of the evidence into the realities of clinical practice. It is common to read in reviews that ‘the methodological quality of the evidence is limited, there are too few studies of merit, and there are no clear evidence-based answers’.¹⁰ To overcome this problem, Gross et al.¹⁰ attempted to translate findings from systematic reviews of neck pain management to clinical practice by the publication of a supplementary ‘Tool Kit’ with simplified summaries and practical application tips specifically aimed at clinicians. For acute whiplash, they reported strong evidence for active interventions, such as exercise, and that advice to rest and the wearing of neck collars should not be recommended.¹⁰ These findings are consistent with recent clinical guidelines for whiplash management, which promote education and assurance to the patient, the maintenance of activity levels, general and specific exercises, simple analgesics and the promotion of coping strategies for acute WAD.^{4–6, 11}

On closer inspection of data from randomised controlled trials included in the above-mentioned reviews, despite a particular intervention showing efficacy, a significant proportion of injured people still develop chronic pain and disability.¹²^–¹⁵ For example, in the study by Proviniciali et al.,¹² approximately 18% of participants were worse or only reported minimal improvement following a multimodal treatment intervention. In the study by Rosenfeld et al.,¹⁵ 48% of participants receiving an active exercise intervention still reported greater than low pain levels following treatment. Additionally, there is evidence available to indicate that the introduction of evidence-based clinical guidelines for the management of WAD (based on the promotion of activity as discussed above) did not either improve health outcomes for injured people or decrease costs.¹⁶ Thus, the current advocated approach is clearly not a panacea for whiplash.

The emerging multifactorial nature of WAD suggests that while the current guidelines may benefit some whiplash patients, they are likely to be inadequate for the management of those with a more complex condition, including both marked physical impairment and psychological distress. This has been recognised in more recent clinical guidelines, which have attempted to include recommendations for the identification of factors such as sensory disturbance and psychological distress, although they fall short of recommending what treatment should be provided to those with this clinical presentation.⁴ The now greater understanding of the physical and psychological characteristics of the condition offers the opportunity to guide the development of improved management approaches in the acute/subacute stage of injury.

The provision of advice and education

Clinical guidelines for whiplash recommend the provision of education and advice for individuals who have sustained a whiplash injury.⁴^–⁶ A recent qualitative study in Western Australia that explored the experiences of patients with acute whiplash in relation to the management of injuries, as well as general practitioners, indicated that injured people sought reassurance and understanding of the implications of their condition.¹⁷ However, a number of the general practitioners interviewed were unaware of their patients’ concerns, feelings and fears about the injury.¹⁷ Few qualitative studies of whiplash are available, so this one is important in that it suggests that this disconnection between patient and practitioner may challenge quality patient-centred care and detrimentally influence outcomes.¹⁷ The findings of this study are supported by a survey of emergency departments in the United Kingdom, where it was found that inconsistent advice was often provided to patients with acute WAD and that advice about return to activity and appropriate use of collars was rarely provided.¹⁸ Of interest was the common encouragement to pursue a personal injury claim, even extending to the sponsorship of advice leaflets by personal injury solicitors.¹⁸ This may potentially facilitate delayed recovery in view of recent findings that poor expectations of recovery are associated with persistent pain and disability.¹⁹

These two studies were conducted in very specific geographical areas, so it is not known whether the results are transferable to other jurisdictions. Nevertheless, it is concerning that whiplash-injured people may not be receiving appropriate and helpful information. In saying this, a recent Cochrane review concluded that there was moderate evidence of no effect on outcomes for various forms of advice alone, focusing on resumption of activity in acute WAD, although this conclusion was based on the results of just two studies.²⁰ One study used a mailed-out video,²¹ and the other an educational pamphlet provided in the emergency department.²² Other forms of education, such as internet delivery or education about the pain neurophysiology, have not been investigated in patients with WAD, although these approaches show benefit for other conditions, such as low back pain.^23,²⁴

In summary, although patients understandably want advice on the prognosis and implications of their injury,¹⁷ it is not clear that advice per se will improve outcomes, and the most effective form and nature of the advice/education remains to be established.

Is pain control important?

The most consistent predictor of poor functional recovery following whiplash injury is initial levels of pain and disability.^1, ^{2, 25} Reported pain levels do not have to be high, as moderate or greater levels of pain and disability (pain: visual analogue pain scale >5 out of 10; disability: neck disability index >30%) demonstrate prognostic capacity.^25,²⁶ It would seem logical that a primary aim of early whiplash management would be to decrease levels of pain. Consistent with this are current recommendations for pain management that advocate adequate pain relief following acute injury.^27,²⁸ Despite this, very few trials of pain relief using medication in the early stages of whiplash have been conducted. One study showed that infusion of methylprednisone, provided in a hospital accident and emergency setting, for patients with acute whiplash resulted in fewer sick days over six months and less disabling pain than in those in the placebo group.²⁹ While interesting, this seems a rather drastic management approach that would not be feasible in community primary care settings. In a recent randomised controlled trial, little benefit (pain relief) was found from the use of muscle relaxants (cyclobenzaprine), either alone or combined with non-steroidal anti-inflammatory drugs (NSAIDs), for patients with acute neck strain in emergency departments.³⁰

Some clinical guidelines recommend that analgesics can be used for acute whiplash but not routinely, and only when there is documented improvement in patient outcomes;⁵ few include pain relief as an aim of treatment.⁶ Such recommendations are predominantly consensus-based due to the lack of high-quality trials.^4,⁵ This seems at odds to recommendations for acute pain after other injuries or surgery, where pain relief is seen as mandatory.²⁸ There seems to be a disparity between recommendations for other painful conditions and whiplash with respect to pain management. Presumably, this discrepancy has arisen due to the lack of randomised controlled trials specifically investigating pain control for patients with acute WAD. Thus, it is clear that further investigations of early pain-relief strategies for patients with acute whiplash are required.

Of course, pain relief can be achieved or enhanced via means other than medication, including advice and education,²⁸ or via some physical interventions, including exercise.³¹ Therefore, by whatever means, decreasing pain should be an aim of management, particularly for those individuals reporting moderate or greater levels of pain.

Physical characteristics of acute WAD and implications for management

It is clear that motor and postural control impairments, including movement loss, altered cervical and shoulder girdle muscle recruitment patterns, kinaesthetic deficits and disturbed eye movement control, have been identified in individuals with an acute whiplash injury;^32,³³ these have been discussed in detail in Chapter 7. The presence of such findings suggests that rehabilitation strategies directed at ameliorating these impairments may enhance recovery. However, as outlined above, while interventions based on trying to increase activity and restore movement have been shown to be somewhat beneficial in reducing pain and disability, significant numbers of patients still make the transition to chronicity.^12,¹⁵ A trial of specific neck exercises and manual therapy for patients with chronic whiplash demonstrated only a modest effect on pain and disability, with preliminary data suggesting that this intervention was ineffective for those with associated sensory hypersensitivity.³⁴ Although it should be noted that this latter study involved patients with chronic WAD, such a trial for patients with acute WAD, where participants are subgrouped according to their sensory presentation, is yet to be reported. Additionally, motor or movement impairments have been shown not to be predictive of poor recovery.^26,³² Together, these findings suggest that motor deficits, although present, may not play a key role in the development or maintenance of chronic symptoms following whiplash injury. This is not to say that treatment directed at ameliorating motor dysfunction should not be provided to whiplash-injured people, but, rather, that the identification of such impairments may not equip the primary care provider with useful information on either prognosis or treatment responsiveness.

Identification of sensory hypersensitivity

The early presence of sensory hypersensitivity (widespread decreased pain threshold to several stimuli) has been shown to be a feature of individuals with acute whiplash and higher levels of pain and disability,³³ and is associated with poor functional recovery.^35,³⁶ These changes are indicative of augmented central pain-processing mechanisms; these phenomena are discussed in depth in Chapter 5.

These sensory disturbances have implications for the management of acute WAD. As sensory hypersensitivity is not present in all those with an acute injury,³⁶ it is important for clinicians to be able to identify such processes in individual patients. Unfortunately, at this stage, there is no ‘gold standard’ per se for the assessment of central hyperexcitability. Clues as to its presence can be gained from both the patient interview and physical examination. Patient reports of mechanical and thermal allodynia, high irritability of the pain and sleep disturbances may be indicative of augmented central pain-processing mechanisms (Table 11.1).⁷

Table 11.1 Findings from patient interviews that may be suggestive of central hyperexcitability

Symptom	Example of patient report
Mechanical allodynia/hyperalgesia	Pain with touch Pain from clothes or bedclothes
Thermal allodynia/hyperalgesia	Pain with cold (e.g. ice, cold weather)
Irritable condition	Pain that is easily aggravated but difficult to settle infers the presence of sensitisation
Sleep disturbances	Difficulty sleeping due to pain

Neuropathic pain questionnaires, while not yet frequently used in the assessment of common musculoskeletal pain conditions, may provide an indication of central hyperexcitability. Thirty per cent of an acute whiplash cohort reported features indicative of neuropathic pain (S-LANSS ≥ 12).³⁷ This group showed higher levels of pain and disability, cold hyperalgesia and heightened bilateral responses with the brachial plexus provocation test (BPPT).³⁷

The physical examination also provides additional clues. The presence of allodynia with manual light touch of the patient is indicative of disturbed central pain-processing mechanisms.³⁸ Pressure pain thresholds can be measured with commercially available pressure algometers, with control and whiplash data available for comparison (Fig 11.1).^39,⁴⁰ Clinical measurement of cold pain thresholds is more difficult. The use of thermorollers, which can be set at predetermined temperatures, has been suggested,⁴¹ but at this stage no clinical test is available with which to quantify cold pain threshold. The BPPT has been proposed as a measure of central hyperexcitability,^42,⁴³ as hypersensitive responses to this test have been demonstrated in people with acute and chronic whiplash.^36,⁴⁴ A bilateral loss of range of movement (elbow extension) has been shown to be associated with decreased pressure and cold pain thresholds in whiplash.⁴² In view of these findings and the familiarity of many musculoskeletal practitioners with the test, it is suggested that it may be a useful clinical tool in the assessment of hypersensitivity in neck pain. Table 11.2 summarises physical tests that may be useful in the evaluation of central hyperexcitability.

Figure 11.1 Measurement of pressure pain thresholds (PPT) over the median nerve trunk with an electronic pressure algometer. (Somedic AB, Sweden)

Table 11.2 Findings from physical examination that may be indicative of central hyperexcitability

Clinical tests	Interpretation
Manual examination of the neck	Presence of allodynia (pain with light touch) infers central hyperexcitability
Manual examination of structures away from the neck (e.g. upper limb nerve trunks)	Presence of allodynia/hyperalgesia infers central hyperexcitability
Pressure pain thresholds	Decreased pain thresholds at sites away from the neck may indicate central hyperexcitability
Cold sensitivity measured with thermorollers	Pain with thermorollers at 20°C—cold hyperalgesia
Brachial plexus provocation test (BPPT)	Bilaterally reduced elbow extension infers central hyperexcitability of motor responses