Psychological Stress and the Surgical Stressor

Introduction

Perioperative and postoperative morbidity and mortality are seen as correlates of the preoperative condition of the patient, the quality of surgical care provided, and the extent of surgical stress. The latter are of clear importance. Considered here are pre- and postoperative stress responses—psychological, behavioral, biologic—and patients' view of illness, hospitalization, and surgery as stressors. We begin with defining stress and the similarity of physiologic models of surgical stress and psychological stress. We note that stress covaries with negative affect, such as negative mood and anxiety and depressive symptoms. Stress in critical periods in the patients' experience, e.g., awareness of illness/diagnosis, anticipation of surgical treatment, and short- and long-term recovery, is described, and empirical relationships to morbidity and mortality are discussed. We conclude with a prompt to consider psychological stress and sequelae in prehabilitation and postoperative surgical care.

Stressors and Stress Responses

Stressors and the stress response are conceptually distinct. Though a bit unsatisfying as it is circular, a stressor can be defined as an event in the environment which most people would find stressful. Indeed, data reliably confirm that, on average, people undergoing divorce, bereavement, caregiving, and importantly, surgery, report greater stress than those not experiencing these stressors. What are the characteristics that define a stressor? Several have been offered, including (1) the level of adaptation required to respond to the stressor; (2) the immediacy of harm, the duration, and the degree to which the event is uncontrollable; (3) the demands of the event exceeding one's capacity/resources to respond; and (4) the stressor interrupts one's goals, including those for psychological or physical well-being. Some characteristics may be more relevant than others in particular situations, but taken together, we can assume that the awareness and anticipation of surgery is a potent stressor and for many, one that does not readily resolve with the occurrence of surgery per se.

Individuals subjectively (psychologically) appraise a stressor, one's capacity to respond to it (behavioral), and physiologic systems are activated (e.g., fight or flight processes) to support behavior to respond. Hypothesized by many (see examples: cardiovascular, diabetes ) and tested by some (see example: cancer ), biobehavioral elements play a role in adaptation to a health stressor and potentially, downstream disease/illness outcomes.

The principal aspect of psychological stress is cognitive, i.e., perceiving an event as stressful. That is, the individual first appraises the threat and then his or her capacity to respond to it. ^, This appraisal process determines the type, direction, and intensity of stress-related emotions (e.g., anxiety, anger, fear, sadness). Individual differences among people also influence appraisals, such as past experience with the stressor, one's perceived ability to cope, and other social determinants (e.g., see associated chapters on financial resources, race, and others). In short, stress responses of individuals vary, even when the precipitating event (e.g., type of surgery) is similar.

In addition to cognitions and negative emotions, stressors prompt behaviors/behavioral change (“flight or fight”). Although there are exceptions, people generally engage in less healthy behaviors when under stress from an event or when perceiving stress. For example, people reporting greater perceived stress are likely to exercise for less time on fewer days, report lower self-efficacy for meeting an exercise goal, or feel less satisfied with their exercise. Stress is also related to sleep difficulties. Stress is not only the leading cause of temporary insomnia, but lack of sleep may also be a source of stress. Stress is associated with increases in health-damaging behaviors. People under stress are likely to increase alcohol intake, smoke more cigarettes, and eat more “fast food,” and high calorie foods.

What are the physiologic responses to psychological stress? Essentially, the system wide physiological responses of the surgical stress response are common to physiologic responses to psychological stress. Two major regulatory pathways exist: the hypothalamic–pituitary–adrenocortical (HPA) axis and the sympathetic adrenomedullary (SAM) axis, providing the basis of stress adaptation. In brief, psychologic stressors activate the brain in a top-down fashion; descending information is stored in the hypothalamus and ascending information in the brainstem. The two pathways act in unison, ensured by bidirectional connection between their centers. Both have physiological responses in common and are viewed as innate survival mechanisms designed to reestablish homeostasis as quickly as possible after stress exposure/injury. Repeated demands, however, tax the body's ability to respond and return to normal, producing “wear and tear” or “allostatic load” (see accompanying chapter). Notably, psychological stressors are able to activate the physiologic adaptational systems even without a physiological stimulus.