Our results question the usefulness of calcitonin in chronic phantom limb pain and stress the potential interest of N-methyl-D-aspartate antagonists. Sensory assessments indicated that peripheral mechanisms are unlikely important determinants of phantom limb pain. Ketamine, but not calcitonin, affects central sensitization processes that are probably involved in the pathophysiology of phantom limb pain.

Small-dose ketamine combined with morphine for PCA provides no benefit to patients undergoing major orthopedic surgery and cannot be recommended for routine use.

No abstract

Using a novel method to analyze drug combinations, the study supports combinations of morphine with ketamine in a ratio of 1:1 and a lockout interval of 8 min for postoperative PCA following spine and hip surgery.

Patient-controlled analgesia with morphine and ketamine is safe. It produces side-effects which, however, are infrequently a reason for discontinuing the regimen. It is also associated with low pain scores and high patient satisfaction.