Does preoperative anxiety level predict postoperative pain?

AORN Journal, March, 2007 by Felicia Vaughn, Harriet Wichowski, Gerry Bosworth

Preoperative anxiety is recognized regularly during patient assessments, and varying levels of anxiety exist from patient to patient. Typical anxiety before surgery comes from fear of the unknown; however, higher-than-normal levels of anxiety may be overlooked or discounted by caregivers in the preoperative area.

Research has shown that preoperative anxiety affects patients on both a physiological and a psychological level. (1) Anxiety can alter the way a person thinks, feels, and acts. On a physiological level, anxiety can alter a patient's vital signs. This may be the first indication to a nurse in the preoperative area that a patient is experiencing significant anxiety. Anxiety also may be responsible for cognitive and behavioral changes. Psychological changes are individualized and reflect a person's baseline personality. (1)

Research also has shown that anxiety lowers immunity and delays healing, (2) and many studies have focused on understanding this complex biochemical process in the body. According to Hughes, (3) measurable physiological and psychological changes occur in the body because of anxiety. These changes include fluctuation in vital signs and changes in mood and behavior. Anxiety results in the release of epinephrine (ie, adrenaline) into the bloodstream causing blood vessel constriction, increased heart rate and force of contractility, increased blood pressure and temperature, flushing and sweating, and many other changes. (4) Anxiety also causes psychological symptoms such as inability to concentrate, difficulty performing simple tasks, and decreased interest in usual roles. (5)

Postoperative pain also is problematic during a patient's surgical experience. Pain after a procedure is the most common fear encountered in preoperative patients. (6) This existence of this fear is validated by studies that have repeatedly shown that pain is inadequately treated in 30% to 80% of surgical patients. (6)

A review of current literature was conducted to investigate the relationship between preoperative anxiety and postoperative pain. Several published studies have demonstrated correlations between the two, suggesting that increased postoperative pain can be predicted. If this is so, nurses have a responsibility as health care providers to institute preventive measures to reduce postoperative pain. The evidence gathered during this review may result in a more psychosomatic and proactive approach to pain relief rather than administration of postoperative pain medications only.

ANXIETY AND SURGICAL RECOVERY

The role of anxiety in surgical recovery was explored in 1958 by Janis. (7,8) He hypothesized that a curvilinear relationship (eg, a relationship that does not follow a straight line) exists between a person's level of anxiety and pain. He called his theory "the work of worry." In this theory, moderate levels of anxiety helped to prepare the patient for the distress of surgery. Levels of anxiety lower or higher than normal were considered to be maladaptive and to negatively affect surgical recovery. Lower anxiety could leave the patient unprepared for postoperative pain, and higher anxiety levels might sensitize a patient to noxious stimuli. (8)

Many studies were conducted in the 1950s and 1960s that tried to replicate pain and anxiety in a laboratory. These studies found positive correlations between anxiety and response to painful stimuli and also found minimized responses to pain with decreased anxiety levels. (9) It seems doubtful, however, that anxiety from life experiences can be replicated in a laboratory. More recent studies have addressed real-life situations and surgical stress in particular.

Current literature and research is based on the theory of a linear rather than curvilinear relationship between anxiety and pain, meaning that with increased anxiety there is an increase in pain. If a relationship exists between preoperative anxiety and postoperative pain, then patients with high levels of anxiety should be identified preoperatively, and care providers could prepare those patients for potential postoperative pain by speaking with the patient's surgeon about antianxiety measures and pain management. If pain control strategies are not already in place for these patients, their quality of care could be decreased. As a worse-case scenario, the patient may have a negative surgical experience resulting in the fear of ever having surgery again.

CLINICAL SIGNIFICANCE

Establishing a link between preoperative anxiety and postoperative pain may allow health care providers to predict a patient's postoperative response. For this to occur, information about the correlation would need to be disseminated to nurses employed in the perioperative area. Nurses then would be able to identify patients with high levels of anxiety preoperatively and anticipate the potential for increased pain postoperatively. This is a matter of importance both in theory and in clinical practice. There is great variability in response among patients who undergo the same surgical procedure. Any means of predicting this variability would result in better patient care and satisfaction. (10) If preoperative anxiety levels can predict postoperative pain, patients should have alternative treatments made available from a holistic perspective with antianxiety strategies and education about coping mechanisms. Nurses may be better able to anticipate pain control issues because of their unique position in patient care.