BACKGROUND The analgesic properties of ketamine are associated with its non-competitive antagonism of the N-methyl-D-aspartate receptor; these receptors exhibit an excitatory function on pain transmission and this binding seems to inhibit or reverse the central sensitization of pain. In the literature, the value of this anesthetic for preemptive analgesia in the control of postoperative pain is...

BACKGROUNDS Impairment of gastrointestinal (GI) motility is an undesirable but inevitable consequence of surgery. This prospective randomised controlled study tested the hypothesis that postoperative thoracic epidural analgesia (TEA) with ropivacaine or a combination of ropivacaine and morphine accelerates postoperative GI function and shortens the duration of postoperative ileus following majo...

Morphine pharmacokinetics were studied in 17 premature neonates (26-34 weeks' gestation) after intravenous infusion during the first 24 hours of life. Infants received either standard dose morphine that comprised of a 100 micrograms/kg/hour loading infusion for 2 hours followed by a maintenance infusion of 12.5 micrograms/kg/hour, or a high dose of 200 micrograms/kg/hour for 2 hours followed by...

The authors conducted a randomized, prospective study comparing epidural morphine with patient-controlled intravenous (iv) morphine in 30 patients recovering from total hip or total knee arthroplasty. Six, 18, and 24 hr postoperatively, patients used a 10 cm visual-analogue scale to indicate both their current degree of discomfort and the maximum discomfort they had experienced since the previo...

BACKGROUND Patients receiving total intravenous anesthesia (TIVA) with propofol have been shown to experience less postoperative pain. We evaluated the post-operative analgesic effects of propofol compared with sevoflurane maintenance of anesthesia in liver surgery. This study was registered at ClinicalTrials.gov (NCT02179437). METHODS In this retrospective study, records of patients who unde...

Three rhesus monkeys, physically dependent on morphine, were trained to press a lever for food on a fixed ratio of 10 responses. A tone, initially a neutral stimulus, was aperiodically presented every third or fourth session, 5 min before and after the intravenous injection of nalorphine, a morphine antagonist which produces an immediate withdrawal syndrome in morphine-dependent monkeys. After ...

BACKGROUND The evaluation of pain intensity during the immediate postoperative period is a key factor for pain management. However, this evaluation may be difficult in some circumstances. The pupillary dilatation reflex (PDR) has been successfully used to assess the analgesic component of a balanced anesthetic regimen. We hypothesized that PDR could be a reliable index of pain intensity and cou...

OBJECTIVES Systemic β-endorphin, an endogenous opioid and stress hormone, has been demonstrated to correlate with the postoperative pain intensity, however its putative role as a postoperative pain biomarker has not been cleared. METHODS Thirty patients scheduled for elective hysterectomy were included into the study. Postoperative pain was assessed by a numeric rating scale from 0 to 10. Pla...

Data concerning the effects of morphine on human pancreatic secretion are fragmentary and inconclusive. In the present study, we evaluated the effects of morphine on pure pancreatic secretion in nine subjects with external transduodenal drainage of the main pancreatic duct performed after biliary tract surgery. Intravenous infusion of a small dose of morphine, 40 microgram/kg/h, during pancreat...