Prevalence and characterization of postoperative pain in the Postanaesthesia Care Unit.

INTRODUCTION: Immediate postoperative pain occurs initially after surgery, while the patient is in the Post-Anaesthesia Recovery Unit. Very few studies assess this pain in this most immediate phase.

OBJECTIVE: Cross-sectional study of the prevalence and characteristics of immediate postoperative pain in patients after surgery.

MATERIAL AND METHODS: Between August 2014 and February 2015, a sample of 503 patients from the Post-Anaesthesia Recovery Unit was followed. Immediate postoperative pain was assessed (by the patient and the researcher) using the visual analogue scale (VAS; range 0-10) on 5 occasions after surgery. The impact of numerous factors (age, gender, type of surgery, type of anaesthesia and analgesic) on the pain, as well as variation in vital signs and the presence of side effects, were analysed.

RESULTS: Assessment of the pain showed overall VAS values of 2.2±2.8 on all occasions. Pain was reported to be of greatest intensity 20min after the patients' arrival in the Post-Anaesthesia Recovery Unit (P<.001). The VAS values reported by the researcher (1.4±2.0) were lower than those reported by the patients. Although there was a very strong correlation (R2 =0.82; P<.001) and they followed a parallel distribution, there was moderate concordance (kappa=0.4). Plastic surgery and neurosurgery were the specialties with the highest percentages of VAS values in the strong intensity range (8-10). Patients with regional block techniques (with or without general anaesthesia) had lower VAS values than other general anaesthesia groups. Male patients and older patients displayed less pain than female and young patients, respectively (P<.001).

CONCLUSIONS: Studying the characteristics of postoperative pain at such an early stage allows for improved management. It helps to predict, according to the type of surgery and the anaesthesia used, those patients in which higher VAS values may be seen and to better adapt analgesic therapy.