Procedure-specific postoperative pain treatment

The aims of this thesis are: To give an overview of one of the serious consequences of acute pain – the transition to chronic pain; To measure and rank pain intensity in a large number of surgical groups in order to define the surgical groups where pain treatment is insufficient and those where pain control is adequate; To determine possible reasons for inadequate pain relief: to identify patient and surgical factors that are associated with postoperative pain intensity, as well as: to analyze whether their influence is dependent on the type of surgery; To obtain a better insight into patient’s pain perception and the impact of acute pain by analyzing different pain outcome variables next to pain intensity. Outline of this thesis: Acute postoperative pain is known to be the most important risk factor for the development of chronic postoperative pain. Chapter 2 reviews the transition from acute to chronic postoperative pain and its consequences. Chapter 3 describes and compares pain intensity, pain treatment, and anesthesia technique of 179 different surgical groups. In Chapter 4, more than 800 cesarean-section patients are analyzed and compared to more than 2,400 hysterectomy patients with respect to anesthesia and analgesic techniques, to identify potential causes of insufficient pain treatment after cesarean section. In Chapter 5 the procedure-specific influence of gender, age, and preoperative chronic pain intensity on postoperative pain scores is investigated using the 30 most frequently performed surgeries involving over 22,000 patients. Chapter 6 further examines the potential role of gender in the development of postoperative pain. In addition to pain intensity, other relevant outcomes such as wish for more analgesics or pain-related interferences are used to indicate the clinical relevance of gender-specific pain perception. Chapter 7 analyzes the influence of the duration of surgery on postoperative pain. In Chapter 8, the factors influencing satisfaction with postoperative pain treatment are analyzed based on data from the PainOut registry. Chapter 9 aims to define optimal cut-off values to divide the 11-item numeric rating scale (NRS 0-10) of postoperative pain intensity into three frequently used categories (mild, moderate, and severe pain). In Chapter 10 results of the studies are discussed and directions for improvement and future studies on postoperative pain treatment are outlined.