Postoperative Pain and Analgesic Use After Total Knee Arthroplasty

This prospective, monocentric observational study evaluates postoperative pain intensity and analgesic consumption in adult patients undergoing primary total knee arthroplasty (TKA). The study focuses on anesthesia techniques routinely used in clinical practice, including general anesthesia with peripheral nerve block, general anesthesia with an epidural catheter, spinal anesthesia with peripheral nerve block, and spinal anesthesia alone.

The primary methodological aim is to compare postoperative pain trajectories (NRS) and total analgesic use during the first 48 hours after surgery across anesthesia strategies. Secondary observations include adverse effects related to analgesia, patient satisfaction, and the need for therapeutic interventions such as fluid administration, vasopressors, antiemetics, or adjustments in analgesic regimen.

Independent variables include type of anesthesia, ASA physical status, age, sex, BMI, type of peripheral nerve block, and duration of surgery. Dependent variables include postoperative pain scores, analgesic consumption, adverse events, and patient-reported satisfaction.

The study is designed to identify clinically relevant differences in postoperative pain control and to explore factors associated with hypotension and other perioperative complications. Findings may support optimization of perioperative analgesia and guide clinical decision-making in anesthesia management for TKA.

Inclusion criteria

• Age 18-100 years
• Primary total knee arthroplasty (TKA)
• ASA physical status I-III
• Glasgow Coma Scale (GCS) score of 15
• Ability to understand study procedures and provide informed consent
• Ability to cooperate during pre-anesthetic evaluation
• No severe sensory impairment (e.g., blindness, deafness)

Exclusion criteria

• Revision or reoperation of TKA
• ASA score IV or higher
• Refusal to participate or inability to provide informed consent
• GCS ≤ 14
• Limited legal capacity
• Active psychiatric disorder
• Chronic use of strong opioid analgesics
• Neurological disease affecting pain perception or cooperation
• Cognitive impairment or language barrier preventing questionnaire completion
• Use of anesthesia techniques other than GA + PNB or SA + PNB (e.g., epidural anesthesia, local infiltration without PNB)