34.4 Adaptation Theories and Models

Stress-Response Theory

The stress-response theory reflects the identification of the body’s nonspecific reaction to a need (threat or stressor) (Selye, 1956/1976). Selye’s description of the approach to illness during his medical education was that it was diagnosis based. Each patient was approached and given a particular diagnosis, and treatment was suggested accordingly. As an early medical student, he made an association that although the patients had different infections, there were similarities. Ultimately, he determined the patients’ physiological responses did share commonalities, and he identified this as the stress response (Selye, 1956/1976).

The stress-response theory involves the chemical (hormonal) actions and reactions upon recognition of a stressor by the limbic system. This reaction continues to the hypothalamus, which initiates the release of CRH, resulting in secretion of adrenocorticotrophic hormone (ACTH) from the anterior pituitary gland. The ACTH causes the adrenal glands to release corticosteroids, most notably cortisol, and to activate the ANS, specifically the SNS. This causes release of fight-or-flight catecholamines: norepinephrine and epinephrine. Under normal circumstances, when the threat has been resolved, the effects of SNS stimulation are opposed by its counterpart, the parasympathetic nervous system (PSNS), and its rest-and-digest actions.

Selye’s (1956/1976) research did not stop with merely identifying stress and its chemical actions and reactions. He continued to examine stress from various angles and with different experiments, through which he further specified the stress response as involving phases he branded as the GAS, which is discussed in the following paragraphs.

General Adaptation Syndrome

The general adaptation syndrome (GAS) involves the concept that stress causes a three-stage syndrome of events resulting in either adaptation or exhaustion (potentially death) (Figure 34.7). The first stage is that of alarm, at which time the SNS is triggered. The activation of the SNS is likely apparent in signs of bronchodilation, tachycardia, tachypnea, elevated blood pressure and glucose, and pupillary dilation, as the body is prepared for facing the stressor. Such confrontation may involve physical or mental confrontation of the stressor, or a combination of both.

The second stage of the GAS is that of resistance. It is during this phase that effective adaptation allows the threat from the stressor to dissipate, and activation of the PSNS opposes the stimulating effects of the SNS. The chemicals released during the alarm phase and the SNS fade, and homeostasis is restored. If, however, ineffective coping by either conscious or subconscious means is apparent, the resistance stage can be extended, and maladaptive results become apparent. These maladaptive results may become apparent in physiological or psychophysiological behaviors and symptoms and in subsequent chronic diagnoses and disorders.

Unresolved adaptations to stress prevent a return to homeostasis and continuation to the third stage of the GAS: exhaustion. At this point, the hormones released during the alarm phase and their reactions have dwindled, and the organism does not have the resources to continue resisting the stressor. This stage can sometimes be prolonged by medical interventions, as healthcare providers order and nurses administer exogenous catecholamines and corticosteroids to critically ill patients. Patients whose compensation ability has been drained may be supported by intravenous medications, intubation, and ventilation, until such time as their own adaptive abilities are revived or reach a point of depletion that is irrecoverable.

Figure 34.7 Selye’s general adaptation syndrome theory consists of three phases with an associated time factor. modification of work from Psychology 2e. (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

Allostasis and Allostatic Load Theories

Allostasis is a concept related to homeostasis (Figure 34.8). The two are considered as nearly opposites in achieving and maintaining equilibrium. Homeostasis is the balance represented by normal vital signs, laboratory findings, and mental state. Stressors lead to instability, and the body naturally attempts to return to and maintain the state of homeostasis. The body’s responses to stressors (e.g., bronchodilation, tachypnea, tachycardia, hyperglycemia) are necessary and life supporting, but the increased effect of these responses over time can be detrimental (Cherry, 2020; Guidi et al., 2021; Igboanugo & Mielke, 2023). The short-term response, with prompt return to normalcy after a challenge, is associated with homeostasis. Allostasis has been described as the ongoing changes within the body in response to stress. The greater the challenge, the more variability there is in the response. As previously established, allostatic load is the response to the collective capacity of events and related chronic stress.

Figure 34.8 The diagram shows baseline as the solid blue line; the orange lines indicate the dynamic nature of equilibrium in (1) homeostasis and (2) allostasis. (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

Allostatic overload describes the situation when the threat or stress is more than the coping ability of an individual (Guidi et al., 20201; Igboanugo & Mielke, 2023). This may be seen as similar to a lack of effective coping during the resistance stage of the GAS, with an ultimate transition to the exhaustion phase if psychophysiological interventions are not taken or are unsuccessful. The following are examples of potential diagnoses ensuing from allostatic load (and overload):

• DM
• cancer
• HTN
• arteriosclerosis
• psychiatric/mental health disorders

Roy’s Adaptation Model

Roy’s adaptation model (RAM) is a holistic approach to nursing as a combination of art and science, structured as a science, model, and practice discipline containing various elements. The model and elements note the inclusion of (1) the goal of nursing, (2) health, (3) environment, and (4) nursing activities (Gonzalo, 2024). The RAM provides a comprehensive foundation for all aspects of nursing and patient interactions, including psychophysiological concepts throughout the life span (Table 34.5). Nursing’s goal is to foster adaptive behavior and alter ineffective behaviors to become effectively adaptive.

Integral to the RAM are the interactions of the person (an individual or a group) and the system. The system is composed of the inputs, outputs, control, and feedback (Gonzalo, 2024), which are compared to the functions of machinery (Figure 34.9). Scientifically, it is noted that the possibilities for adaptation are not infinite but are limited by the body’s resources and the person’s ability to cope. The strictly scientific approach to stress and adaptation is enhanced by the values of humanism, and the role of the person. The notion that the patient can be more than merely a reflexive participant in stress, and at least in some circumstances exert some control of stress, is a component of this model.

Figure 34.9 This diagram shows the RAM, from input through output, and the associated feedback mechanism. (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

Psychophysiological Stress Model

The psychophysiological stress model (PSM) reflects the relationship between the mental and physical reactions and adaptations to stress. The adaptive component of the stress response may be where the relationship is most evident. Whether the body is responding to a physical or psychological threat, negative results tend to occur when the level of stress does not adequately dissipate, which typically happens during resistance or through adaptation. Effective coping leads to positive adaptation and minimizes poor outcomes. Maladaptive coping mechanisms, however, contribute to the signs, symptoms, and diagnoses of chronic disorders, including physical diagnoses like HTN, DM, HF, as well as mental health diagnoses like anxiety, depression, and PTSD. The stress response involves actions at the hypothalamus, pituitary gland, and adrenal glands, which cause physiological reactions. Hormones released activate the ANS, with particular signs of stimulation of the SNS. Effects from the SNS involve increased actions in the respiratory and cardiovascular systems and release of corticosteroids; nervousness and anxiety are also common consequences. Interestingly, anxiety may also be the original stressor starting the cascade of events. Considering that the limbic system of the brain is where stress is identified by the body, and that the hormones also act chemically as neurotransmitters, the relationship between the psychological and physical responses to stress are unmistakable. Sometimes these interactions occur in a rather cyclical fashion, either initiating or fostering the processes.

Identify Predisposing Risk Factors for Stress Reactions

Like the diagnoses induced by stress, there are many risk factors for development of stress and how it is handled by the body. As nurses plan their care of patients, an important piece can be to distinguish those risk factors that increase the patient’s likelihood of being adversely affected by stress. Such risk factors begin early in life, with stressors imposed during fetal development, based on maternal health status, mental health, and behaviors. Such early risk factors continue with ACEs and the effects of such adverse events on adaptation throughout the life span.

Despite negative experiences, there are some who are innately optimistic. There are also those who are pessimistic despite supportive environments and mostly pleasant experiences. Also, there are people who are predictably optimistic or pessimistic, based on incidents perceived as accordingly good or bad. Additionally, ascertaining whether a patient reaches high levels of anxiety, or a crisis point, easily can be a contributing risk factor for stress responses cascading out of control and away from balance. Therefore, a general outlook can be a predisposing risk factor of homeostatic maintenance.

During a nurse’s interaction with a patient, helping the patient (or family) to determine what coping mechanisms have been successful in the past, as well as those that have been ineffective, may contribute as risk factors for inability to maintain homeostasis. After all, if an adaptive technique has not been helpful in the past, a patient’s reliance on it is not likely to be fruitful with repeated use. Another piece of a patient’s history that may be considered a stress risk factor is health and surgical history. Well-controlled diagnoses may still contribute to stress, either by worry about it or by the actual stressful event of an exacerbation. Similarly, while some surgeries offer definitive and complete resolution of a problem, sequelae or side effects may occur, involving subsequent stress and inflammatory responses. This adaptation technique toward maintenance of homeostasis is represented by the assessment phase of the nursing process. Within the CJMM, this is the phase Recognize Cues.

Identify the Stressor

As the nurse considers a patient who is experiencing a stressful situation, it is important to identify the stressor. The assessment findings or cues from the previous risk factors step may prove helpful in narrowing down possible stressors to that which is currently causing psychophysiological stress responses. This adaptation technique reflects “analysis,” the second phase of the nursing process, or “analyze cues” from the CJMM.

At this point, the nurse investigates aspects of the patient’s life that may shed light on specific stressors influencing the patient. This may include potential contributions from health history and current state, including current socioeconomic situations such as family and employment status (or lack thereof). Recent events that have already been identified as having produced stress, or that have caused issues in the past, are worthy of analysis and consideration. With the nurse and patient working together to analyze the possibilities, the stressor (or multiple stressors) is typically identifiable.

Identify Personal Feelings Toward Stressor

For patients who are attempting to effectively cope with and adapt to stress, once a particular stressor has been identified, the next step toward hopeful success is to identify personal feelings relative to the stressor. Sometimes, stress responses are subconscious, as the body reacts to changes in homeostasis with automatic chemical reactions. Cases of this nature often reflect physical assaults to equilibrium, such as the vasoconstriction, aldosterone, and ADH release that are initiated to counter fluid volume deficit from blood loss or dehydration. These automatic reactions are often associated with acute stress circumstances, without the patient cognitively recognizing or responding.

An example of fluid volume deficit is an older adult patient who does not drink enough water. With this additional information in mind, the nurse can help identify contributions to the stressful incident. What is prohibiting adequate fluid intake? The nurse determines that the factors are forgetfulness and diminished thirst. And, because the patient has difficulty ambulating, it is too complicated to get up to fix a drink. As the nurse uncovers these issues, the patient can be collaborated with once again to determine what factors can be changed, and which among those the patient wants to change in order to minimize stress, maximize effective adaptation, and restore homeostasis.

An ability and desire to change may reflect the same coping behaviors; sometimes, though, the fact that change is possible does not mean the patient wants to do so. This can pose a barrier to coping, leading to refusal to try or use of defense mechanisms. Maladaptive mechanisms unfortunately perpetuate negative results of stress and, ultimately, chronic stress-induced disorders. Nurses can assist patients through education about the following:

• pathophysiological processes
• prevention
• treatment compliance
• actions for effective coping:
  • regulating emotions
  • relaxing
  • novel approaches to stress and its relief
  • supportive relationships
  • professional therapy
  • positive self-talk and activities
  • participation in spiritual or religious actions (Peterson, 2021; Wilson, 2023).

Maintaining homeostasis continues with the analysis phase of the nursing process or the CJMM. During this step, collected data from the assessment or recognition phases are analyzed for possible interventions and actions by the nurse and patient. Subsequently, they will be arranged by priorities.

Decide Action

At this point, the nurse has identified risk factors, applicable stressors, and the patient’s feelings toward the stressors. With these pieces in place, the stressors can be prioritized, and actions can be considered and decided on. If there is but one stressor identified or noted to be of importance, prioritization is simple; frequently, however, patients have more than one issue going on at once, or the source of stress is complicated with multiple actions possible. Based on severity of symptoms, patient goals, and the patient’s personal priorities, decisions need to be made about action(s) to plan and implement. To continue the previous exemplar about fluid volume deficit, the nurse previously considered possibilities for the patient’s hypovolemia, including forgetfulness, diminished thirst, and ambulation challenges limiting access to fluids. With the patient’s input, it is determined the most important action is to improve the availability of fluids. The patient feels that even without feeling thirsty, it will be easier to remember to drink if water is handy.

Evaluate Outcome

Finally, in an effort to produce and foster adaptation techniques to maintain homeostasis, the evaluation process should be employed. At the point where actions were decided, patient goals and nursing goals were both considered in order to determine which action(s) to plan and act on. This period allows for the nurse to evaluate the outcomes of the previous actions; when the actions were implemented, were the established goals achieved? If so, then the cycle of the nursing process continues with assessment or recognition occurring again to determine the next important cues. If goals were not met, the process again begins, but with focus on what modifications may prove helpful for goal achievement and how to implement such changes.