Repeated and escalating preoperative subanesthetic doses of ketamine for postoperative pain control in patients undergoing tumor resection: a randomized, placebo-controlled, double-blind trial.

Background: Ketamine induces a short-term effect on postoperative pain when administered intravenously immediately before or during acute pain. Repeated administration of low-dose ketamine may induce long-term pain relief in chronic pain syndromes.

Objective: The aim of our study was to determine whether ketamine's effect on acute postoperative pain could be enhanced and prolonged and analgesia consumption reduced if it was administered intramuscularly in repeated and escalating subanesthetic doses many hours before surgery.

Immediate postoperative pain in orthopedic patients is more intense and requires more analgesia than in post-laparotomy patients.

Objective: To compare the immediate postoperative pain intensity between orthopedic and general surgery patients and evaluate the extent of severe pain in each group.

Design: Observational, open-label study.

Setting: Post-anesthesia care unit (PACU) in a tertiary, university-affiliated hospital.

Effects of intravenous patient-controlled analgesia with buprenorphine and morphine alone and in combination during the first 12 postoperative hours: a randomized, double-blind, four-arm trial in adults undergoing abdominal surgery.

Background: Intense pain in the first 12 hours after major abdominal surgery requires the use of large amounts of analgesics, mainly opioids, which may produce undesirable effects. Buprenorphine (BUP) is not typically used intravenously in this setting, particularly in combination with morphine (MO), due to concerns that BUP might inhibit the analgesic effect of MO.

Objective: This study compared the analgesic effect of BUP and MO separately and in combination for postoperative pain control in patients undergoing abdominal surgery.

Morphine with adjuvant ketamine vs higher dose of morphine alone for immediate postthoracotomy analgesia.

Background: Thoracotomy is associated with severe pain. We hypothesized that the concomitant use of a subanesthetic dose of ketamine plus a two-third-standard morphine dose might provide more effective analgesia with fewer side effects than a standard morphine dose for early pain control.

Methods: We conducted a 6-month randomized, double-blind study in patients undergoing thoracotomy for minimally invasive direct coronary artery bypass or for lung tumor resection.

Ketamine for acute and subacute pain in opioid-tolerant patients.

Prolonged acute pain, especially that of oncologic neurological origin, is at times difficult to control; it is seldom entirely alleviated by opioids. We report eight patients with severe pain, three of whom suffered from new onset oncologic metastatic bone pain, others had previous pain syndromes and presented with exacerbation of pain. Pain was associated with hyperalgesia and allodynia phenomena in two patients and with phantom pain in a third one.