Editorial Article | Open AccessAvailable online freely| Peer Reviewed
Chronic Pain One To Five Years After Lung Transplantation
Chronic bodily pain after lung transplantation has received little attention. Therefore, the aim was to provide a multidimensional assessment of self-reported chronic pain 1-5 years after lung transplantation and its relationship with self-reported psychological general well-being (PGWB) and self-efficacy. This multicenter, cross-sectional study is a part of the Swedish national study: Self-management after thoracic transplantation (SMATT). In total, 117 lung transplant recipients, all white, due for their yearly follow-up at one (n=35), two (n=28), three (n=23), four (n=20) or five years (n=11) after transplantation were included. Of these, 113 reported their pain on the Pain-O-Meter (POM), which provides information about pain intensity, quality, location, and duration. In addition, they responded to the PGWB instrument and the Self-Efficacy instrument for managing chronic disease. The prevalence of pain was 51% after 1 year, 68 % after 2 years, 69.5 % after 3 years, 75 % after 4 years and 54.5 % after 5 years. Women experienced higher pain intensity and worse sensory and affective burden than men. Psychological general well-being was the main factor that contributed to the experience of pain. Better perceived psychological well-being lowered the odds for pain, while higher self-efficacy reduced the probability of experiencing pain. Many of the lung recipients lacked pain treatment and were uncertain about the reasons behind their pain. Chronic bodily pain is a common and serious symptom up to five years after lung transplantation. Female lung recipients experience more pain and pain related illness than men.
Chronic pain has wide-ranging detrimental effects across various life-domains and also affects health related quality of life (HRQoL) after solid organ transplantation (SOT) (1-3). The rationale behind this study is that the extent to which lung recipients experience chronic bodily pain in the years after lung transplantation has received little attention in the literature.
Pain is a complication that might hamper self-management (4) due to decreased ability to cope with the physical and psychosocial consequences inherent in being a lung recipient. Self-efficacy, defined as the perceived capability of the lung recipient to perform a specific action required to achieve a concrete goal (5), might also be seriously limited.
After liver transplant, 26% of recipients stated that they suffered severe bodily pain (1) and in another cohort 18% reported pain in an extremity and 40% had arthralgia (6). Bone pain and fractures were also reported as the most significant non-immunological postoperative complication (7). Furthermore, deterioration in bone disease can lead to compression fractures of the vertebrae and pain (8). Kidney recipients treated with cyclosporine reported severe pain, restriction of movement, transient musculoskeletal pain, and a leg bone pain syndrome (9-12). Musculoskeletal-neurologic complaints and low back pain were prevalent following heart transplantation (13), and patients with at least mild pain after heart transplantation reported worse HRQoL than the general population and were less likely to be employed (3). Peripheral neuropathy is an undesirable complication after SOT with unexpected onset, rapid escalation of symptoms, lack of provider monitoring, and poor provider response to patient reported symptoms (14).
When discussing pain after SOT it is necessary to address Calcineurin-Inhibitor induced Pain Syndrome (CIPS), identified by Grotz et al., 2001 (15). In SOT recipients the overall incidence of the syndrome ranges from 1-17 % (16). The usual onset occurs 1 to 3 months after the introduction of Calcineurin Inhibitors (CIs) and the syndrome presents as symmetric bilateral pain in the lower extremities involving the bones of the feet, ankles
Indications for transplantation and medication among the 117 included lung recipients are shown in Table 2. The mean age of the pain free recipients was 53 years (SD 13.5) (range 22-70 years). Of the 113 recipients who answered all three instruments, 74 (65.5 %) reported pain, 40 women and 34 men with a mean age of 53 years (SD 12) (range 18-74 years). In the pain group, 71.6 % of the recipients were over the age of 50 years. In the group of patients younger than 50 years the prevalence of pain was 64.6 %, thus there was no significant difference between the two age groups. None of the patients were enrolled in a rehabilitation program at the time of their yearly follow-up
The key findings in this study are:
·Chronic pain is very common in the first five years after lung transplantation ranging from 54.5-75 % of lung recipients.
·The most common pain locations are the chest, back, and legs.
·The pain reduces psychological general well-being and self-efficacy.
·Female lung recipients report higher pain intensity and worse sensory and affective burden than male lung recipients.
Chronic pain was more common than we could possibly have imagined. Moderate to severe persistent postsurgical pain occurred in 5-10 % of the patients in a Danish nationwide study of chronic pain after lung transplantation (28), which in turn was lower than that reported after non-transplant thoracotomy. The self-rated prevalence of generalized pain in the general Swedish population is 10-15 % (29-30). In total, 24 % of the population is living with persistent pain, i.e., lasting for more than 3 months, with an increased risk of various co-morbidities (31). For example, among persons with chronic pain the lifetime prevalence of depression is 58-86 % and anxiety 35-62 % (32). In the Regional database of care consumption in the south of Sweden about 3 % of the population is diagnosed with generalized pain each year. While such pain might be viewed as a specificdisease per se, pain is also a common symptom of many other diseases including chronic conditions (33). Thus, the prevalence of pain among lung recipients is far above that of the general population, which constitutes an important aspect of long-term management after lung transplantation.
We did not explore the cause of the pain. However, the pain locations suggest multiple causes such as the incision, CIPS (especially pain in the hands, feet, joints, and head), and the side-effects of immunosuppressive drugs other than CNIs. The chest pain may be due to post thoracotomy pain syndrome (PTPS) that may have an incidence of more than 50 % (34) and be related to intra operative factors such as whether anterolateral thoracotomy or classic posterolateral thoracotomy was applied. The apparent etiology of PTPS is nerve damage and loss of superficial abdominal reflexes (34), thus it is noteworthy that in ten cases the personal models for explaining the pain involved nerve injury. None of these factors were explored in the present study, but will be analyzed in an ongoing prospective study. Due to the sensory descriptions in at least hands and feet it is reasonable to believe that we partly deal with neuropathic pain. For some time it has been recognized that inflammatory mediators released from immune cells can contribute several persistent pain states. Immune cell products might have a crucial role not just in inflammatory pain but also in neuropathic pain caused by damage to peripheral nerves or to the CNS (35). Accumulating evidence suggests that non-neuronal cells such as immune cells, glial cells, keratinocytes, cancer cells and stem cells play active roles in the pathogenesis and resolution of pain. Recent studies also suggest that bacterial infections regulate pain through direct actions on sensory neurons, and specific receptors are present in nociceptors to detect danger signals from infections (36). Since all the lung recipients were treated with CNIs more than one year our understanding is that the immunological condition caused by the anti-rejection treatment might be one reason behind the high prevalence of pain along with the occurrence of bacterial infections.
The findings reveal that 18 recipients experienced no consequences in their everyday life, suggesting that it is possible to experience pain and still mange one s daily occupation without limitations. However, in a majority of cases chronic pain affects everyday life, which is supported by the Danish survey (28) where daily social activities were limited in 29-92 % of the participants and where more than half of the LuTx felt that their QoL was compromised due to pain. The consequences regarding HRQoL from our data are currently being analyzed and will be reported later.
In our study PGWB was reduced, but we do not know whether pain causes anxiety, depression, and poor general health or if reduced PGWB increases the experience of pain. The design does not permit any suggestions or conclusions regarding cause-effect. One concern is that self-efficacy was impaired among LuTX with pain. The ability to achieve certain goals is important for the experience of health and as self-efficacy is a pre-condition for self-management (37), the latter might also be limited by chronic pain. We argue that chronic pain after lung transplantation might hamper the recipient s ability to manage the symptoms, treatment, physical and psychosocial consequences, and life style changes inherent in living with the chronic condition of being a lung recipient.
As recommended in the consensus report on gender differences in pain and analgesia (38), we tested the pain experience in both sexes. Women with pain experienced significantly higher pain intensity and pain related illness than men with pain. Despite the lack of evidence, our understanding is that the differences in experienced pain intensity refer more to societal based gender phenomena than purely biological sex differences. The gender role might differ for female lung recipients and our findings suggest that both PGWB and self-efficacy affect the pain experience. It is well-established that there is a 2 to 6 fold greater prevalence and intensity of chronic pain syndromes in women compared to men (38). As women are more likely than men to have a history of clinical pain experiences and pain history influences pain perception, we argue that pre-transplant multi-dimensional pain assessment should be mandatory for all transplant candidates, but especially for female lung transplant candidates.
The limitations of this study are the design and its retrospective nature. The investigation included data from the only two thoracic transplant centers in Sweden with different staffing conditions at the outpatient lung transplant clinic, which possibly affected the recruitment of participants during the study period. The slightly different approach to the care of these recipients in the pre, peri, and postoperative setting contributes to the heterogeneity of the study population. Although this heterogeneity might be considered a weakness, it can also be viewed as a strength because it may accurately represent the cross-section of patients undergoing lung transplantation in Sweden. As pain is a subjective sensation the data are self-reported and thus represent the inside perspective of the recipients experience of pain. Consequently, this opens up the possibility of different interpretations of the items pertaining to pain and how pain intensity is rated by the study participants. However, these findings from our clinical research are probably more relevant to the relief of chronic pain after lung transplantation than those from studies involving laboratory animals or healthy, pain-free humans.
The POM has been used among various organ transplant recipients and is therefore known to work in this context. The POM includes both a mechanical VAS and two lists of pain descriptors also present in the MPQ (39). Especially the POM Affective scale has been shown to be adequately reliable, and sensitive to analgesic treatment (22, 39). It has also been shown to discriminate patients with acute myocardial infarction from patients with chest pain but no diagnosis of a myocardial infarction. On the down side, POM Affective scale may be less strongly related to other measures of affective disturbances e.g. measures of anxiety and depression than the POM Sensory scale or the VAS measure of pain intensity on the POM (39).
This is the first multi-dimensional exploration of chronic pain after lung transplantation. It reveals that chronic bodily pain is a common and serious symptom for up to five years after lung transplantation. Female lung recipients experience more pain and pain related illness than men. Consequently, multi-dimensional pain assessment should be performed pre-transplant as well as regularly at follow-up after lung transplantation. It is also necessary to adopt a gender perspective. In addition to providing proper analgesia, an advanced nurse practitioner specialized in pain management and the use of complementary methods might be useful together with patient education aimed at relieving suffering and promoting healthy adaptation and self-efficacy despite pain.
None of the authors have any financial relationship with a commercial entity. This work was supported by the Thure Carlsson foundation.