Vorhersage postoperativer Schmerzen nach laparo- skopischer Cholezystektomie

Zusammenfassung

Die vorliegende Studie untersucht die Zusammenhänge zwischen klinischen und soziodemographischen Daten, 2 spezifischen Persönlichkeitsmerkmalen – Selbstwirksamkeitserwartungen und Kontrollüberzeugungen – und dem postoperativen Schmerzgeschehen nach laparoskopischer Cholezystektomie. Es wird postuliert, daß zwischen den beiden Persönlichkeitsmerkmalen und den postoperativen Schmerzparametern, der Theorie entsprechend, positive und negative Zusammenhänge bestehen. Weiters wurde ein multipler Zusammenhang zwischen diesen Variablen angenommen. Die postoperativen Schmerzparameter wurden in Form von subjektiver Schmerzempfindung, Verlangen und Verbrauch von Analgetika über die Dauer der ersten 3 postoperativen Tage ausgewertet. Die Datenanalyse von 56 Patienten erbrachte signifikante, der Theorie entsprechende Korrelationen zwischen den präoperativ erhobenen Persönlichkeitskonstrukten und den Parametern des postoperativen Schmerzgeschehens. Auch die errechneten multiplen Korrelationen waren der Annahme entsprechend eindeutig, signifikant und klärten auch einen erheblichen Anteil der Varianz auf. Variablen wie Differentialdiagnose, operative Vorerfahrungen oder Alter und Geschlecht der Patienten waren nicht von Relevanz. Die Variable „Chirurg” wurde zum Zweck der Untersuchung konstant gehalten. Die Ergebnisse der Studie legen nahe, daß das postoperative Schmerzgeschehen zu einem Großteil von der Persönlichkeit des Patienten abhängt und sich auch vorhersagen läßt.

Abstract

The study consists of a prospective randomized controlled clinical trial of patients undergoing laparoscopic cholecystectomy. Besides medical and sociodemographic data, two personality factors – self-efficacy and locus of control – were found to predict postoperative pain. Self-efficacy describes the expectations of a person to successfully execute the behavior required to produce behavioral outcomes. Locus of control, in the extreme case, is a personality factor which is represented by an internal orientation in which the individual believes that rewards are brought about by his own action, versus an external orientation, in which the individual believes that rewards are the result of powerful others or chance factors and fate. We postulate that the two personality factors correlate with postoperative parameters of pain and that there are also multiple correlations between them.

Methods: For the two personality factors we applied two questionnaires which were given to the patients preoperatively. One is well established and the second one was developed and tested especially for this study by us. We used subjective pain, demand for and quantity of analgetics as parameters of postoperative pain until the 3rd day after surgery.

Results: The statistical analysis of 56 patients revealed that the two personality factors proved to be the most relevant and significant factors (p<0.05–0.001) to predict and also to explain high rate of variance up to 60% of postoperative pain. Patients with a high expectation of self-efficacy in pain management and an internal locus of control had a significantly lower subjective pain, demand for and quantity of analgetics than patients with low expectations of self-efficacy or a high external orientation with chance factor and fate in control. Medical and sociodemographic variables did not predict any parameters of pain. Some surgical factors were kept constant.

Discussion: These findings underline the importance of personality factors also in postoperative pain, which can be predicted by self-efficacy and locus of control. This result means for us that self-efficacy and locus of control influence the cognates of personal pain perception within the context of the individual history of experiences and seem to be changeable preoperatively by special psychological training.