Pain following extremity injury - Management, Predictions and Outcomes
Acute pain is a frequent complaint of patients requiring emergency medical care. Acute pain as a result of (potential) tissue damage warns and protects the body from (further) damage. Normally, acute pain disappears along with the healing process. However, in some cases, persisting pain outlasts the healing process and no longer serves as a protecting mechanism. This pain without any useful biological function is called chronic pain. Chronic pain is prevalent and has an impact that often extends well beyond the pain itself. Chronic pain and related disability often leads to complex social and psychological maladaptations affecting patient’s quality of life, leads to health care overutilization, as well as many other substantial costs for example due to productivity loss. It is increasingly recognized that acute and chronic pain represent a continuum rather than distinct entities. Chronic pain patients often relate their pain onset to acute injury such as surgery or trauma, drawing attention to the need to prevent the progression from acute to chronic pain. The transition from acute to chronic pain is still a complex and poorly understood developmental process. A range of injury-, psychosocial-, socio-environmental and patient-related factors has been associated with the persistence of pain. Against this background, the PROgnostic factors for the Transition from Acute to Chronic pain in Trauma patients (PROTACT)-study was designed.
The PROTACT-study was initiated as a one year prospective follow-up study with the primary aim to determine prognostic factors involved in the transition from acute to chronic pain after extremity injury. This will give the ability to target high-risk patients in the emergency setting and to intervene on one or more of these factors thereby preventing the development of chronic pain. Secondary objectives were to describe the current state of pain management following extremity injury and to determine the consequences of extremity injury and developing chronic pain post-injury in terms of quality of life. The PROTACT-study was conducted in adult patients, aged 18 until 69 years, who presented themselves to the emergency department (ED) of Medisch Spectrum Twente in Enschede with isolated musculoskeletal extremity injury caused by blunt trauma. During the 22 months inclusion period, 1994 adult patients with extremity injury attended the ED and met the study criteria. Of these patients, 803 participants provided written informed consent. Participants were asked during the follow-up period to complete 4 or 5 questionnaires. Data from the emergency medical services (EMS), ED and hospital electronic patient registry were collected. Collected data included potential prognostic factors, injury and pain-related characteristics, pain management and patient’s perspective of their quality of life. The inadequate and ineffective pain treatment in emergency care is a well-documented problem worldwide. Chapter 2 shows that oligoanalgesia (inadequate pain relief) is a serious problem in patients with acute musculoskeletal pain following extremity injury. The prevalence of pain following extremity injury is high: 4 out of 5 patients presented themselves to the ED with moderate to severe pain. And even though sixty percent of the patients used analgesics (pain medication) somewhere in the chain of emergency care, more than two-thirds of the patients still suffered moderate to very severe pain at discharge from the ED. The importance of analgesics in the ED is reflected by the significant and clinically relevant higher reduction of pain in patients who were administered pain medication. Chapter 3 represents the outcome of the primary aim of the study. In the PROTACT-study, a comprehensive set of potential prognostic factors was used to determine incidence and to identify prognostic factors for chronic pain following both minor and major isolated musculoskeletal extremity injuries. At 6 months post-injury, 43.9% of the patients still had some degree of pain and 10.1% developed chronic pain, defined as persisting pain with a pain score ≥4 on the site of injury. Patients aged over 40 years, in poor physical health, with pre-injury chronic pain, pain catastrophizing, high urgency level (as surrogate for injury severity) and severe pain at discharge were found to be at high-risk for developing chronic pain. Only two prognostic factors, severe pain at discharge and pain catastrophizing, are potentially modifiable. Acute musculoskeletal pain following extremity injury may have many consequences including medical, psychosocial and economic problems. Health-related quality of life (HRQoL) has become more important when it comes to evaluating outcome following injury and disease burden. In chapter 4 the impact of extremity injury and chronic pain on health from the patient’s perspective is described. There is ample evidence that extremity injuries are painful and cause significant interruption to quality of life in the early post-injury phase. High prevalences of health problems were found. Changes immediately after injury are seen for 7 of the 8 HRQoL dimensions, except for general health which is recalled over the last year. Also on the long-term the consequences of injury are still present. Overall health state of the injured patients at 6 months post-injury was significantly lower than before injury. A significant decrease was present in physical health state dimensions vitality, bodily pain, physical functioning and role limitations due to physical functioning. That pain plays a crucial role in our daily life is revealed by the impact of developing chronic pain on HRQoL. The impact on HRQoL is much higher in patients who developed chronic pain post-injury; these patients had a considerable loss in HRQoL both on physical and mental health state. The single index of health (utility score) decreased with at least two times the minimally important difference; a change in outcome that a patient would identify as important. Moreover, the utility score at six months in patients who developed chronic pain is substantially lower than in the rest of the study population. These latter patients will regain their pre-injury level of function. One other reason that indicates prevention of chronic pain is necessary. It is assumed timely and adequate treatment of pain intervenes the progression from acute to chronic pain and thereby reduce the risk of developing chronic pain. Worldwide, different strategies to enhance pain management have been developed in response to inadequate pain relief such as pain management protocols or clinical guidelines and staff educational interventions. The pre-post intervention study in chapter 5 aims to evaluate the effect of a nurse-initiated pain protocol in the ED. With the implementation, emergency nurses were allowed to administer analgesics, including opioids, according to a pre-defined protocol, without the patient first being assessed by an ED-physician. This is important because there can be a considerable delay between the patient’s presentation and being seen by an ED-physician, and even a longer time to analgesic administration. Especially in patients presenting to the ED with minor extremity injuries this protocol might be useful to optimize pain treatment, because these patients are usually triaged to a low (semi-urgent) triage category which typically results in an extended waiting time to physician’s assessment. The pre–post intervention comparison shows that the implementation of the protocol lead to an increase of analgesic provision, a shorter time to analgesics and a higher (clinically relevant) pain relief in patients with acute musculoskeletal pain following extremity injury. Despite these improvements in pain management, a relatively high percentage of patients was still discharged with moderate to severe pain. Inaccurate pain assessment is a consistent finding in various clinical settings including the ED. Accurate pain assessment is crucial for effective pain management. Nurses not always rely on patients’ self-reported pain and apparently make their own assessments of patients’ pain based on a combination of nonverbal cues, such as type of and time since injury or patient behaviour. Due to the subjective nature of pain, it can be very difficult to quantify patients’ pain. In chapter 6 the discrepancies in pain assessment between patients and nurses were analysed. In the PROTACT-study nurses significantly underassessed patients’ pain with a mean difference of 2.4 points on an 11-points numeric rating scale. Even more important is the issue of clinically relevant differences (33%) between both assessments. In a majority of 63% patients’ pain was clinically relevant under assessed. In our population, pain was in particularly under assessed by nurses in women, in persons with a lower educational level, in patients who used prehospital analgesics, in smokers, in patients with injury to the lower extremities, in anxious patients and in patients with a lower urgency level (surrogate for minor injuries). There should be awareness among nurses that these patients are at high-risk for underassessment. Underassessment can result in under-treatment of pain if the emergency nurses rely on their assessment to conduct further pain treatment. In chapter 7 the impact and implications of the main findings of the PROTACT-study were discussed. Chronic pain is confirmed to be a common complication following extremity injury. The health impact of developing chronic pain is substantial; it causes impaired quality of life. Six prognostic factors for the development of chronic pain were found. Of these factors, pain severity in acute pain phase and pain catastrophizing are potentially modifiable. A nurse-initiated pain protocol, which was implemented to reduce inadequate pain relief in the ED, appears to lead to an increase of analgesic provision, a shorter time to analgesics and a higher (clinically relevant) pain relief. Although this showed that severe pain can be reduced, the prevention of chronic pain is not investigated. Despite improvements in pain management, the results reflected by the amount of patients discharged with moderate to severe pain showed that there is still room for improvement. Accurate pain assessment is crucial for effective pain management. Nurses significantly underassessed patient’s pain. By drawing attention to patients’ self-reported pain and minimizing assumptions, and the routinely use of pain assessment tools, pain management might further improve. Furthermore, it is desirable to educate patients about the importance of communicating unrelieved pain and the use of pain medication. Due to the limited number of studies which identified prognostic factors for chronic pain following extremity injury and the different methodology used only a limited set of consistently found factors that predict the development of chronic is available. When future studies use a more common and systematic approach in order to better identify the scope and magnitude of those at high-risk of developing chronic pain, this will contribute, together with current findings of the PROTACT-study, to identify (modifiable) physical and psychosocial prognostic factors as input for a brief risk screening tool that includes assessment of prognostic factors to identify injured patients at high-risk for chronic pain in the early acute pain phase and to stratify treatment based on their risk.
