Association of Tryptophan: Kynurenine Metabolites with Healing in Chronic Venous Leg Ulcers

OBJECTIVE

Chronic wound healing is a complex process that is still not well understood. The tryptophan (TRP)-L-Kynurenine (KYN) pathway has recently been under increased scrutiny in regards to wound healing. The study applied metabolomics to elucidate the TRP-L- KYN pathway associated with wound healing in chronic venous leg ulcers (CVLUs).

APPROACH

This study used a longitudinal comparative design of 60 serum samples collected from 30 older adult patients with CVLUs, receiving weekly sharp debridement at a wound clinic. The serum samples were collected at baseline and week 4 (healed wounds) or week 8 (non-healed wounds). Liquid chromatography-mass spectrometry (LC-MS) metabolomics was used to analyze targeted metabolites. A Bayesian approach was employed to examine robust correlations between changes in metabolite values and linear healing slope and to compare by group.

RESULTS

The mean age was 71.13 (±9.46). Half of the sample were female and the minority (17%) were Black. The mean values of evaluated metabolites for the non-healed group were consistently lower than those for the healed group. The healed group (n=12) had higher KYN values; Those on a healing trajectory (n=23) had lower KYN levels and higher TRP levels at baseline and over time. There was moderate support (Bayes Factor = 3.70) for a negative association between change in Kynurenic Acid and linear healing slope (r = -0.35, CrI = -0.62, -0.04, PD= 98%). Results suggest KYN and TRP may be markers for healing in individuals with CVLUs.

INNOVATION AND CONCLUSION

Gaining a better understanding of the associations between the TRP-L- KYN pathway and the healing of CVLUs may help to clarify the links of inflammation with the rate and success of wound healing. Biomarker development focused on the TRP-L- KYN pathway could be pursued, if the associations are further supported by focused research studies.

Associations Among Wound-Related Factors Including Biofilm, Wound-Related Symptoms and Systemic Inflammation in Older Adults with Chronic Venous Leg Ulcers

Objective: The purposes of this observational prospective study were to (1) characterize the wound-related factors (wound area, the presence of biofilm, and total bacteria), wound-related symptoms (fatigue, pain, exudate, itching, and edema or swelling), and systemic inflammation (level of serum C-reactive protein [CRP]), and (2) explore associations between wound-related factors, wound-related symptoms, and systemic inflammation in older individuals with chronic venous leg ulcers (CVLUs) over 8 weeks of wound treatment. Approach: A total of 117 participants who received standardized care (weekly sharp debridement) for chronic venous ulcer were enrolled. We collected clinical data every 2 weeks during the 8 weeks of the study period or until the wound was healed (if healed before 8 weeks). Associations among variables were estimated using a Bayesian approach applied to general linear mixed models. Results: Based on Bayes factor (BF) value, there was extremely strong evidence for the association of biofilm with mean total bacteria (BF >1,000). There was moderate evidence of a direct association between biofilm presence and levels of CRP (BF 4.3) and moderate evidence of direct associations between biofilm and wound-related symptoms, pain and exudate (BF 5.12, 8.49, respectively). Innovation: Wound-related symptoms and the level of systemic CRP were associated with biofilm among patients who were receiving weekly sharp debridement. Symptom severity associated with CVLUs requires assessment and management of wound-related factors and levels of inflammation in addition to symptom assessment. Conclusion: This study is the first to examine associations among biofilm, as wound-related factors, systemic inflammation, wound-related symptoms, and wound healing in clinical settings. Symptom severity, level of systemic CRP, and wound-related factors should be considered as well as assessment of biofilm in CVLU in older individuals with CVLU.

The association of wound factors and symptoms of fatigue and pain with wound healing in chronic venous leg ulcers

The purpose of this study was: (1) to characterise the association of wound area, wound exudate C-reactive protein (CRP), broad-spectrum matrix metalloprotease protein (MMPs), and symptoms of fatigue and pain in individuals with chronic venous leg ulcers (CVLUs) over time and (2) to identify factors associated with the wound healing trajectory in CVLUs. Seventy four participants with CVLU who received weekly sharp debridement were recruited from a wound care clinic during the 8-week study period. To examine associations among wound CRP, MMPs, pain, fatigue, and wound healing trajectory over time, we calculated Bayes factors (BF) based on a linear mixed model. The mean age of participants was 71.8 (SD = 9.8) and the mean wound area was 2278 mm² (SD = 7085 mm² ) at baseline. Higher fatigue was strongly associated with higher MMPs (BF = 9, 95% HDI: [-.05, .43]), lower CRP (BF = 11, 95% HDI: [-.02, .002]), and large areas of wound (BF = 20, 95% HDI: [-.001, .01]). Higher CRP and MMPs activity in wound exudate and higher fatigue were associated with a larger wound area. To facilitate wound healing, clinicians need to utilise the multifactorial approach, which includes wound treatment and management of symptoms such as pain and fatigue, because of the molecular and psycho-behavioural factors involved in wound healing.

Multidimensional Pain Characteristics in Older Adults with Chronic Venous Leg Ulcers

Objective: Pain affects wound healing, treatment, and quality of life because it has significant impacts on physical, psychological, and social well-being. Despite the fact that more than half of chronic venous leg ulcer (CVLU) patients experience mild-to-moderate pain, the multidimensional characteristics of CVLU pain are not well documented. The objective of this study was to describe the multidimensional pain characteristics, including the sensory, affective, cognitive, and behavioral dimensions, of CVLU before debridement. Approach: Participants (N = 40) were recruited from a wound clinic. We conducted a descriptive analysis of clinical data, including pain, wound, and demographic characteristics, collected at the first visit. Results: The mean age of participants was 70.8 ± 9.1 years, 22 (55%) participants were female, and 35 (87.5%) were white. Participants reported mean current pain intensity (2.9 ± 2.7), least (1.2 ± 2.2) and worst (4.8 ± 3.4) pain intensity in 24 h, and tolerable pain level (4.9 ± 2.64) on a 0-10 scale. They described pain as periodic (66.7%, n = 26) with multiple pain quality descriptors (5.4 ± 2.9). Their past pain treatments provided some pain relief (65%, n = 25). For 68% (n = 27), their pain was the same as they expected. Nearly all had a tendency not to tell others about their pain (95%, n = 38). Innovation: This study is the first to describe the multidimensional pain characteristics of patients with CVLU as measured with PAINReportIt. Conclusion: Patients with CVLU reported willingness to tolerate a relatively high level of pain and experience the level of pain they anticipate. Multidimensional pain assessment will assist clinicians to select individualized therapies to manage pain and improve quality of life for these patients.

Metabolomics: Impact of Comorbidities and Inflammation on Sickness Behaviors for Individuals with Chronic Wounds

Significance: Approximately 6.5 million people in the United States suffer from chronic wounds. The chronic wound population is typically older and is characterized by a number of comorbidities associated with inflammation. In addition to experiencing wound-related pain, individuals with chronic wounds commonly experience multiple concurrent psychoneurological symptoms such as fatigue and depression, which delay wound healing. However, these distressing symptoms have been relatively overlooked in this population, although their adverse effects on morbidity are well established in other chronic disease populations. Recent Advances: Inflammation is involved in multiple pathways, which activate brain endothelial and innate immune cells that release proinflammatory cytokines, which produce multiple symptoms known as sickness behaviors. Inflammation-based activation of the kynurenine (KYN) pathway and its metabolites is a mechanism associated with chronic illnesses. Critical Issues: Although putative humoral and neuronal routes have been identified, the specific metabolic variations involved in sickness behaviors in chronic wound patients remain unclear. To improve health outcomes in the chronic wound population, clinicians need to have better understanding of the mechanisms underlying sickness behaviors to provide appropriate treatments. Future Directions: This article presents a synthesis of studies investigating associations between inflammation, metabolic pathways, and sickness behaviors in multiple chronic diseases. The presentation of a theoretical framework proposes a mechanism underlying sickness behaviors in the chronic wound population. By mediating the immune system response, dysregulated metabolites in the KYN pathway may play an important role in sickness behaviors in chronic inflammatory conditions. This framework may guide researchers in developing new treatments to reduce the disease burden in the chronic wound population.

Abstract PO-110: Determining the validity of patient pain markings for wound pain prior to debridement

Introduction: Little research has been done to determine if the wound pain markings correlate with the changes in measured wound size. For cancer patients, wound pain could be caused by the tumor or cancer treatments. The study purpose was to evaluate the validity of patient pain markings (body surface area) as an indicator of wound size and changes in size over time. This study will contribute to the clinicians’ understanding of the patient reported pain outcomes as an indicator of wound healing. Methodology: Among a sample of 40 participants, 22 (55%) were female, 38 (95%) were non-Hispanic, and 35 (88%) were White and 5 (12%) were Black. Mean age of participants was 70.8 (SD=9.1) years, 13 participants completed high school, 16 completed some college, and 11 completed more than college. The majority of the participants (n=23, 58%) were married. All subjects were asked to complete the PAINReportIt, an electronic adaptation of the McGill Pain Questionnaire. Their wound areas were measured using the Silhouette device, which measured the wound length, depth, and volume. Using the subject’s PAINReportIt pain markings on a body outline, the ImageJ software algorithm calculated the body surface area (BSA) in pixels as marked for each pain site. Analyses included descriptive statistics and Kendall correlations. Results: From the 40 unique patients, there were 157 visits where both BSA and wound size data were recorded: 18 patients had 5 visits, 4 had 8 visits, 7 had 3 visits, and 7 had data from 2 visits. As a context to the magnitude of pain the patients reported at visit 1, the mean pain intensity was 2.9±2.7 (0-10 scale). The wounds were in the lower extremity for 39 patients and in the foot for 1 patient. The mean wound area was 2634±8005 mm2. 35 patients reported pain in 1 site, 1 reported 2 sites, 1 reported 3 sites, 2 patients reported pain in 4 sites, and 1 patient did not report pain sites at visit 1 but did so at other visits. The between- subject correlation between the wound size and the BSA area marked was tau=.33 (p<.01). The within-subject correlation between these two measurements was tau=.08 (p=.45). Conclusions: The findings show that the within-subject correlation between repeated BSA and wound area measurements was low, indicating that the BSA is not a good indicator of change in wound area over time. In the future, studies of a larger sample size are needed to confirm the degree of correlation between BSA and wound area.

Citation Format: Jessi Noel, Rishabh Garg, Yingwei Yao, Michael Weaver, Debra Lyon, Joyce Stechmiller, Diana J. Wilkie. Determining the validity of patient pain markings for wound pain prior to debridement [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-110.

Optimizing Nutrition Care for Pressure Injuries in Hospitalized Patients

Significance: It is estimated that up to 50% of hospitalized patients are malnourished. Malnutrition can lead to longer hospital stays, altered immune function, and impaired skin integrity and wound healing. Malnutrition has been found to be a significant factor influencing pressure injury (PI) risk and wound healing. While PI prevention requires multidimensional complex care using a variety of evidence-based strategies, hospitalized patients benefit from interventions that focus on improving oral nutrition to reduce PI risk and enhance wound healing. Unfortunately, malnutrition is often under-recognized and inadequately managed in hospitalized patients and this can lead to higher rates of complications such as PI. Recent Advances: Recent studies suggest that nutritional care has a major impact in PI prevention and management. Strategies, including early identification and management of malnutrition and provision of specially-formulated oral nutritional interventions to at-risk patients, optimization of electronic health record systems to allow for enhanced administration, monitoring, and evaluation of nutritional therapies, and implementation of protocol-based computerized decision support systems, have been reported to improve outcomes. Critical Issues: Unfortunately, there are gaps in the implementation of nutritional care in hospitals. Timely identification and management of malnutrition is needed to advance quality care for hospitalized patients and reduce malnutrition and associated PI. Future Directions: Further research on effective, evidence-based strategies for implementation of all stages of the nutrition care process is needed to reduce pressure injuries and malnutrition in hospitalized patients.

How Well Does the Braden Nutrition Subscale Agree With the VA Nutrition Classification Scheme Related to Pressure Ulcer Risk?

The VA Nutrition Classification Scheme documented by dietitians was found to be superior in assessing nutritional risk and predicting the development of pressure ulcers in acutely ill hospitalized veterans compared with use of the Braden nutrition subscale.

Building a Biopsychosocial Conceptual Framework to Explore Pressure Ulcer Pain for Hospitalized Patients

Although pressure ulcers are a prevalent condition, pain associated with pressure ulcers is not fully understood. Indeed, previous studies do not shed light on the association between pressure ulcer stages and the experience of pain. Especially, pain characteristics of suspected deep tissue injury, which is a new category that was recently added by the National Pressure Ulcer Advisory Panel, are yet unknown. This is concerning because the incidence of pressure ulcers in hospitalized patients has increased exponentially over the last two decades, and health care providers are struggling to ensure providing adequate care. Thus, in order to facilitate the development of effective interventions, this paper presents a conceptual framework to explore pressure ulcer pain in hospitalized patients. The concepts were derived from a biopsychosocial model of pain, and the relationships among each concept were identified through a literature review. Major propositions are presented based on the proposed conceptual framework, which integrates previous research on pressure ulcer pain, to ultimately improve understanding of pain in hospitalized patients with pressure ulcers.

Bodily pain intensity in nursing home residents with pressure ulcers: analysis of national minimum data set 3.0

Clinical reports suggest that superficial pressure ulcers produce pain, but that pain decreases as the wound advances in stage. This study of the relationship between pressure ulcer stage and bodily pain intensity in nursing home residents was a secondary analysis of the national Minimum Data Set 3.0 assessment data in long-term care facilities, collected from nursing home residents at least 65 years of age. Data were examined from residents with pressure ulcers who completed a bodily pain intensity interview between January and March 2012 (N = 41,680) as part of the MDS comprehensive assessment. After adjusting for other variables (e.g., cognition, functional impairment, presence of comorbidities, use of scheduled pain medication, and sociodemographic variables), bodily pain intensity for those with more severe pressure ulcers in comparison to those with Stage I ulcers was higher by 11% (Stage II), 14% (Stage III), 24% (Stage IV), and 22% (suspected deep tissue injury). Because multivariate analysis showed that greater bodily pain intensity was associated with an advanced stage of pressure ulcer, health care providers should assess bodily pain intensity and order appropriate pain management for nursing home residents with pressure ulcers, particularly for those with advanced pressure ulcers who are vulnerable to greater bodily pain intensity.

The Role of Doxycycline as a Matrix Metalloproteinase Inhibitor for the Treatment of Chronic Wounds

Many chronic wounds fail to heal with conventional therapy, resulting in disability and impaired quality of life. New technologies using recombinant growth factors, autologous growth factors, or bioengineered skin—tissue substitutes have been shown to be effective, but these treatments are costly. An effective, low-cost treatment to improve healing of chronic wounds is needed. The molecular environment of chronic wounds, like many other chronic inflammatory diseases, contains abnormally high levels of proinflammatory cytokines (tumor necrosis factor [TNF]-α and interleukin [IL]-1β]) and matrix metalloproteinases (MMPs), which impair normal wound healing. In animal models and clinical studies of ulcerative diseases, doxycycline, an inexpensive and Food and Drug Administration (FDA)-approved antibiotic, appears to inhibit members of the MMP superfamily like MMPs and TNF-α-converting enzyme (TACE). This article provides an overview of the roles of MMPs and intrinsic tissue inhibitors of metalloproteinases (TIMPs) in wound healing and the damaging effects of chronically elevated levels of MMPSs in chronic wounds. It also explores the use of topical doxycycline, a synthetic MMP inhibitor (MMPI), to enhance healing of chronic wounds.

Interruption of enteral feedings in head injured patients

This study was undertaken to determine differences between caloric intake and requirements of critically ill, enterally fed, neurosurgical and neurotrauma patients and to determine the nature and frequency of interruptions in enteral feedings in this same population. This descriptive, prospective study was conducted in a surgical intensive care unit (ICU) in a university teaching hospital. The sample consisted of 52 mechanically ventilated, critically ill patients with a mean age of 48.96 years who were receiving enteral nutrition for at least two days. Basal energy requirements, daily nutritional intake and enteral feeding interruption characteristics were recorded for a total of 586 study days. Underfeeding due to interruptions occurred in the majority of patients for the first eight days following initiation of enteral feeding. Reasons for underfeeding were interruptions of continuous tube feedings due to medication administration via the feeding tube (31%), feeding tube displacement (27%), surgery (12%), ileus (9%), radiologic studies (9%), airway management (8%), bedside procedures (3%) and agitation (1%). The frequency of these enteral feeding interruptions may indicate inadequate nutritional support, highlighting the importance of performing daily nutritional monitoring to prevent malnutrition.

Complications of enteral nutrition in hospitalized patients with artificial airways

This study investigated complications of enteral feeding in hospitalized patients with artificial airways. A prospective chart review, using a descriptive design, was used in this study of 51 inpatients in a large southeastern teaching hospital. A low (5.9%) incidence of pulmonary aspiration was found. Diarrhea was also found to be an infrequent complication (2%). The most common complication in this sample was interruption in continuous tube feedings: 24 patients (47%) experienced such interruptions, resulting in potential underfeeding. Further investigation of the adequacy of nutrition of hospitalized tube-fed patients with artificial airways is necessary to determine clinical significance.

Cardiac tamponade resulting from pneumopericardium: case report and implications for the critical care nurse

Pneumopericardium resulting in cardiac tamponade may be caused by a variety of phenomena. The onset of cardiac tamponade can indicate the presence of a rare underlying condition. As a rare complication of mechanical ventilation and PEEP, our patient experienced pneumopericardium that resulted in cardiac tamponade. Perhaps the most crucial therapy of all is astute critical care nursing assessment of patients at risk of developing the life-threatening complication of cardiac tamponade. All critical care nurses should know the signs and symptoms of cardiac tamponade. Through accurate data collection, frequent monitoring, and immediate referral to the critical care team for medical diagnosis and treatment, a patient's death can be prevented.

Pulmonary aspiration in tube-fed patients with artificial airways

Based on the results of this study, it appears that critically ill patients may receive nutritional supplements through the use of a small-gauge, flexible enteral feeding tube without significant danger of pulmonary aspiration. However, the potential for aspiration of tube feedings in any critically ill patient still exists, and further research in this area would contribute to a decrease in morbidity and mortality rates.