The Unified Trauma Theory of High-Stress Level Fatigue a Case of Loyola University Essay

Abstract

The purpose of this paper is to develop a middle-range nursing theory by utilizing the process of theory derivation. Theory derivation is the mechanism that was employed in this project in which a procedure and process that offered an efficient mechanism to understand a phenomenon that had previously lacked description in nursing. The steps of this process are outlined, concluding with definitions and a description of the middle range theory of unified trauma theory of high-stress fatigue, which was developed. In the conclusion of this paper, the implications for nursing are discussed along with areas where further research may contribute to a broader understanding of this phenomenon.

Introduction

Traditionally, the evaluation of trauma care mainly focused on survival, complications and the length of hospital stay as the main contributing factors. However, the mortality rate in large populations of severely injured patients has tremendously declined in the past years by twenty percent (Bardenheuer et al, 2000, p. 355). Nevertheless, the importance of both short-term and long-term outcomes after major trauma has become of global concern in the recent past due to the ongoing development of sophisticated trauma care (Holbrook et al, 1999, p. 751). Researchers have also found out that post-injury functional limitation is a clinically significant complication in trauma patients at discharge and 6-month after follow-up (Holbrook et al, 1999, p. 767). All the same, post-injury depression, serious extremity injury, and the period of stay in the intensive care unit also have a significant impact on the quality of well-being outcome (Holbrook et al, 1998, p.321).

Holbrook et al. 1998 in the first report provided novel and challenging evidence that the importance of dysfunction after major injury had been underrated (p. 322). Little is, however, known to have an empirical foundation to guide the understanding of the phenomena. Although many experiences of trauma patients have been described in the literature, no theories have been found to describe the patients’ experiences after discharge and more Specific on the impact of high-level stress and fatigue that it comes with.

Furthermore, the possibility that IL-6 might participate directly or indirectly in the symptomatology of fatigue in trauma patients is more fascinating and worth further investigation. This is especially due to the lack of evidence about predicting sickness behavior symptoms in early trauma patients. Investigation of IL-6 may also provide valuable information for the prediction of sickness behavior symptoms as early as possible in trauma patients.

Theory derivation is therefore essential in gaining a better explanation and predictions about a phenomenon that is currently poorly understood, or lacks present means of studying (Walker and Avant, 2010, p.241). Theory derivation can help nurses modify a theory from another discipline to creatively develop a theory related to nursing. The steps in theory derivation are not linear and require repetition until the developed theory is suitably inclusive (Walker & Avant, 2010, p. 250). Therefore, the purpose of this paper is to develop a middle-range nursing theory utilizing the process of theory derivation. The theory derivation process was utilized to help in offering an efficient mechanism to understand a phenomenon that had previously lacked proper description in trauma nursing. Throughout this paper, the steps of this process are outlined, concluding with definitions and a description of the middle range theory of unified trauma theory of high-stress fatigue, which was developed. This derived theory represents promising areas in cytokine, psychoneuroimmunology, and trauma research. At the end of this paper, the implications for nursing are discussed along with areas where further research may contribute to a broader understanding of this phenomenon.

Background and Significance

The basic principle of Psychoneuroimmunology (PNI) is that an individual’s adaptive response to the environment involves coordinated interactions between the nervous, endocrine, and immune systems. The biological pathways that connect the brain to the cells and tissues of the immune system include direct innervations of lymphatic tissue by the central nervous system and a shared communication network in which cells of the nervous, endocrine, and immune systems use common molecules and receptors to jointly modulate biological activity. An expanding body of evidence suggests that emotions play a big role in the development and progression of disorders that involve immune processes (Myers, 2008, p.701). Furthermore, accumulated evidence in the research field of PNI has indicated that there is an existence of reciprocal communication pathways between nervous, endocrine and immune systems (Schiepers et al, 2005, p.215).

The adverse physiological and psychological traumatic event is bound to induce a series of reactions. These reactions include; sustained proinflammatory cytokine production and persistent pro-inflammation-based behavioral symptoms such as fatigue, poor sleep, and depressive mood in trauma patients (Irwin, 2008, p. 96). There is evidence confirming that trauma patients exhibit elevations in pro-inflammatory cytokine production, especially IL-6 (Segal et al, 1997, p. 46).

Peripheral proinflammatory cytokines are capable of signaling the brain to induce behavioral symptoms like fatigue, sleep disturbance and depressive mood (Dantzer, 2001a, p.228: Dantzer, 2004a, p. 400.: Dantzer and Kelley, 2007, p.157: Myers, 2008, p. 805). Cytokine-to-brain signaling provides a theoretical base consistent with the evidence demonstrating an association between proinflammatory cytokines and behavioral symptoms of fatigue, sleep disturbance and depressive mood (Foex et al, 1993, p. 373). Pro-inflammatory cytokines such as IL-6 play a significant role in developing depression and can mediate its psychological, behavioral and neurobiological manifestations (Dantzer et al, 2010, p.312).

The cytokine hypothesis of depression recommends that external psychological stressors and internal organic inflammatory diseases or condition stressors induce the inflammatory process (Schiepers et al, 2005, p. 216). Additionally, it has been shown through research that psychological stress might induce an inflammatory response with increased production of pro-inflammatory cytokines (Maes et al, 1999, p. 834). Cytokines had been shown to induce behavioral changes related to some symptoms of depression causing neuroendocrine changes in animals that are similar to those in depressed patients (Wollman and Yirmiya, 2002, p. 189). (Biffl et al, 1996, p. 652) summarized the properties of IL-6 and characterized its response to injury. There are also clinical studies that describe the IL-6 response to trauma (Ayala et al, 199, p. 171: Kremer et al, 1996, p. 269: Maruszynski and Pojda, 1995, p. 883: Ohzato et al, 1993, p. 1560: Segal et al, 1997, p. 43). However, despite the fact that IL-6 is considered to be a mediator of the physiologic short-term phase reaction to injury, excessive and prolonged post injury elevations are associated with increased morbidity (Gebhard et al, 2000, p. 292).

“The result of a hyperactive proinflammatory state marked by excess production of proinflammatory cytokines such as IL-1, IL-6 and TNF and IFN gamma may contribute to the pathogenesis of various human diseases such as allergy, autoimmunity, obesity, depression and atherosclerosis” (Sternberg, 2006, p. 146). It is thus theorized that cytokines released in response to infection or inflammation alert the brain to any real or potential threats and initiate behaviors that are thought to be important for survival (Frink et al, 2009, p. 78). Some even refer to the ability of the immune system to alert or communicate with the brain as a “sixth sense” (Blalock and Smith, 2007, p. 109). Sickness behavior is believed to be adaptive in that it forces an individual to rest and withdraw from activities so that physiological processes can more effectively produce healing (Blalock and Smith, 2007, p. 110). It is now known that proinflammatory cytokines released during infection, inflammation, injury and even psychological stress can signal the brain to initiate behavioral changes that facilitate adaptation to these threats. And as mentioned earlier, cytokine-to-brain signaling has been implicated in mood disorders, particularly depression and fatigue that accompany illness (Dantzer, 2009, p.262).

In summary, it can be evidenced that there is compelling evidence to implicate cytokines’ role in fatigue. The investigation of acute circulating inflammatory markers’ responses is a fruitful area that may provide insight into the role of psychoneuroimmunological processes in trauma patients (Johnson et al, 2005, p.79). Therefore, the purpose of this paper is to explain the theory derivation process, provide an overview of the parent theory of “unified engineering theory of high stress level fatigue” which was utilized in this project as well as to present a new middle range theory of unified trauma theory of high stress level fatigue.

Theory Derivation Process

Theory derivation is an efficient and useful way to develop theory in an area of interest to the discipline when there is a lack of a structural representation of related concepts that are significant to practice. The process of theory derivation involves assessing the equivalence of a theory in a related field, where the explanation and understanding of the phenomenon in that field offers insight and an improved comprehension to areas in one’s own discipline. It is through the analogous process of assessing and comparing related work from outside the discipline that one can gain an improved comprehension and perspective in an area of practice that has not been well defined or articulated. The theory that is utilized from an associated field is modified to fit the new field. Sets of inter-related concepts or pieces of the fundamental elements of the theory structure are revised and transferred to the new field, where there is a more cohesive and systematic view of a phenomenon that previously lacked description (Walker and Avant, 2010, p.180).

There are several steps that are involved in theory derivation. The process begins with being aware of the theory development that currently exists within the profession. If there is adequate and useful theory available, this process would be excessive and unnecessary. One needs to be familiar with the literature related to the phenomenon. The next step in this process is to choose a parent theory, which is usually a theory from another field of practice. The established theory from outside of the discipline offers resourceful information on the phenomenon of interest that is being examined. Once the parent theory is chosen, the author determines relevant information from the parent theory and incorporates either all of the theory or only those parts that are relevant to the derived theory. The final step in theory derivation is to define the relevant concepts and structure from the parent theory. The author then refines and develops concepts, assumptions and theoretical propositions for the purpose of applying the derived theory to the phenomenon of interest in nursing. This process of deriving theory provides the nursing profession with a method for developing new knowledge and gaining a deeper understanding of the phenomenon of interest (Walker and Avant, 2010, p. 112).

Parent Theory

• Scope of theory: Valluri (1961, p.18), proposed “A unified engineering theory of high stress level fatigue” which enables an understanding and allows prediction of the various aspects of fatigue from the same basic model. The proposed model combines certain features of dislocation theory of metals with elasto-plastic analysis of the stress distribution near a crack, and determines an estimate of fatigue life to failure based on estimates of the rate of crack transmission.
• Assumptions: The assumptions of this model include:
  • “ This theory predicts the shape of the familiar stress versus number of cycles curve extending from one fourth of a cycle at the ultimate static tensile strength down to several million cycles and incorporates no additional assumptions in predicting cumulative damage during fatigue” (Valluri, 1961,p. 19).
  • “The theory distinguishes the order of application of stresses in cumulative damage. The weighting factor frequently associated with high stress levels in cumulative damage is implied in the basic model itself” (Valluri, 1961, p. 19).
  • “The theory also discusses the dependence of fatigue upon the several commonly observed variables, some quantitatively and some qualitatively, as well as residual static strength in fatigue and its dependence on material properties” (Valluri, 1961, p. 19).
  • “The inherently statistical nature of the fatigue problem is emphasized and this is attributed to an internal stress existing at the level of the pattern structure” (Valluri, 1961, p.19).
  • “This stress is thought to be due primarily to the existence of a network of dislocations and the solute atoms of alloying elements”. (Valluri, 1961, p. 19).

Concepts and definitions

• Damage in stress- controlled fatigue is defined as the product ‘equivalent’ surface crack length of the longest strain range, both in exponential form (Fatemi and Yang, 1998, p. 17).
• Crack: “the concept of crack is well developed in the engineering discipline and it is defined as a fracture type discontinuity characterized by a sharp tip and high ratio length and width to opening displacement. More so, a line of fracture without completes separation.” (Davis, 1992, p.69).
• Stress: stress in engineering is defined as the load exerted by a force divided by the capacity of the material to resist. More precisely, it is the load in relation to capacity to resist (Rothbart, 2006, p. 105).
• Fatigue: the concept of fatigue in engineering refers to the behavior of materials under the actions of repeated stresses and train. It is defined as the progressive structural damage occurring in a material subjected to conditions that produce fluctuating stresses and strains at some points that may result is cracks or complete fracture after sufficient number of fluctuation (Stephens and Fuchs, 2001, p. 164).
• Structural failure: “is defined as the reduction of the capability of a structural system or component to such a degree that it cannot safely serve its intended purpose. Precisely, it is the system or the components inability to sustain the load for which it was designed.” (Janney, 1986, p. 89)

Derived Theory for Nursing

Scope of theory

In the process of theory derivation, the author may use the entire parent theory or only those portions that are pertinent to the concept of interest (Walker and Avant, 2010, p. 78). The parent theory of “unified engineering theory of high stress level fatigue” was utilized in the development of this middle range theory that includes the linear structure of the theory and the concepts. The proposed “unified trauma theory of high stress level fatigue” encompasses the concept of fatigue which is dependent on previous cracks, high stress level, sustained proinflammatory cytokine production (IL-6), the cluster of other symptoms such as depression and poor sleep. It emphasizes that the high stress is primarily due to the existence of physiological and psychological traumatic event. These physiological and psychological traumatic events lead to high stress level and sustained proinflammatory cytokine production (IL-6). External interventions can avoid fatigue and buffer the effect of stress before fatigue occurs. Success or failures of external interventions (buffers) are the determining factors if the trauma patient will be fatigued. Crack is another important concept in the theory, where the result of previous cracks before the injury such as previous psychological or physical health may impact susceptibility and resistance to fatigue. Precisely, the more previous cracks exist, the more the patient is susceptible to fatigue. For instance, the trauma patient can have no cracks or zero cracks. This theory therefore proposes that stressors will not latch on in the absence of cracks.

The purposes of this middle range theory development are to provide trauma nursing with an improved understanding of the various aspects of stress and fatigue with the consideration of previous cracks and the impact of buffers referred to as the external interventions. Most importantly, this theory emphasizes on the importance of assessing fatigue in trauma patients as follow up measures after discharge, because if fatigue is left unchecked, it will lead to deterioration and worsening health outcomes. This proposed theory emphasizes the importance of developing nursing interventions that can be efficiently targeted to improve outcomes of trauma patients after discharge and buffer stressors. Assessing fatigue and stress is essentially a valuable in tool determining the success and evaluation of external therapeutic intervention

Concepts and definitions

There are four derived concepts from the parent theory in unified engineering theory of high stress level fatigue. A model that represents the image of the middle range theory of unified trauma theory of high stress level fatigue included in the Appendix. The four concepts include:

• Crack: the person’s state before the injury, which includes the previous mental (emotional) and physical health before the event of injury.
• Stress: it can be defined as a negative emotional experience accompanied by predictable biochemical, physiological, and behavioral changes that are directed toward adaptation either by manipulating the situation to alter the stressor or by accommodating its effects (Baum, 1990, p. 654). In the proposed theory, stress is defined as the impact of trauma or rather how the stressor has an effect on the person. In relation to the type of injury to the person physiologic state whether it is going to have an effect or not.
• Fatigue: originally fatigue is defined as a multidimensional experience characterized by distress and decreased functional status related to a decrease in energy (Stein et al, 2004, p. 21). Fatigue is experienced across 5 domains; general, emotional, physical, mental, and vigor domains (Stein et al, 2004, p.22). In the proposed theory, Fatigue is defined as the person’s response to the stressors and the inability for the person to reach for external interventions that would buffer the effect of stressors and be successful. Fatigue eventually leads to deterioration.
• Deterioration: is defined as the worsening of the patient’s condition after experiencing fatigue.

Assumptions

There are three proposed assumptions for the derived theory, which include: 1. Damage is cumulative, 2. Fatigue is statistical. 3. Dislocation occurs in networks.

Propositional Statements

Propositional statements indicate the relationships between the main conceptual ingredients of the theory (Polit and Hungler, 1987, p. 360). In the unified trauma theory of high stress level fatigue there are five relational statements. Which include:

• Fatigue is dependent on previous cracks, high stress level, sustained proinflammatory cytokine production (IL-6), and the cluster of other symptoms such as depression and poor sleep.
• Physiological and/or psychological traumatic events lead to high stress level and sustained proinflammatory cytokine production (IL-6)
• Fatigue can lead to deterioration
• External interventions can buffer the effect of stress before fatigue occurs and avoid fatigue.
• More cracks leads to more susceptibility and resistance to fatigue.

Significance in Nursing

• Potential Utility in Practice: This theory provides new insights for clinical practice and enhances the ability to support individuals with after traumatic events. It also provides clinicians with a useful theoretical framework to guide them through their practice. It provides new information that stimulates research questions where we are provided with the opportunity for scientific inquiry. It is through continued examination and data becoming substantiated over time that we become confident in recognizing new knowledge.
• Potential Utility in Research: The derived theory can help in designing a conceptual model for a research program, as it can also provide a rich source of potential hypotheses for studies. It is hoped that it can help in achieving a body of knowledge about the phenomena of interest. Further research that would aid in testing this theory would be to implement it in clinical practice and measure the relation between the fatigue and stress in trauma patients. Both should be targeted by early treatment interventions and neurobiological research. Lastly, the model could serve well in the development of fatigue and stress measurement tools specific to trauma patients. The goal is to improve the health of trauma patients after discharge for better functional outcomes. This theory could be used for routine screening of trauma patients to identify the risk for fatigue.

Conclusion

Theory derivation process has been helpful in offering an efficient method to understand the phenomenon that had previously lacked description in trauma nursing. It is hoped that the proposed unified trauma theory of high stress level fatigue can provide a framework for understanding trauma patients.

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