Controlling pain in the post-operative setting

Background and aims: Postoperative pain (POP) is a form of acute, intense pain experienced in the period following surgery, whose adequate control is often problematic. This paper reviews determinants and characteristics of POP, together with rationale and current protocols for its management. Determinants/consequences of POP: Main determinants of POP are the type of intervention and the disease motivating surgery, though other factors related to patient (age, pain threshold, sociocultural factors, personality) and setting (pre-operative information, relationship with medical staff) may also influence its perception. POP control is essential to relieve suffering but also to prevent dangerous consequences on organ systems, e.g., reduced cough, atelectasis, increased myocardial oxygen consumption and ischemia, constipation, urinary retention, reduced musculoskeletal mobility and increased risk of deep venous thrombosis. Management of POP: Constant assessment of pain intensity is recommended for optimal POP control. This is mostly achieved pharmacologically with monitoring of side effects. Multimodal analgesia is recommended, combining different drug classes, e.g., an opioid (morphine, pethidine, fentanyl, tramadol, codeine) with a non-opioid (NSAID; Cox-2 inhibitor), delivered through various routes, and including neuraxial use of local anesthetics (bupivacaine, ropivacaine) alone or in combination with other drugs, nerve blocks, antihyperalgesics (ketamine, dextromethorphan) and techniques such as patient-controlled analgesia (PCA) and pre-emptive analgesia. An efficient organization of pain services is also recommended. Conclusion: Acute post-surgical pain represents a crucial problem, but the multimodal therapeutic approach has enhanced the efficacy of pain control while minimizing side effects of each modality. Further improvement of POP control will necessarily involve better organization of pain services.