title: The analgesic effect of combined treatment with intranasal S-ketamine and intranasal midazolam compared with morphine patient-controlled analgesia in spinal surgery patients: a pilot study.
abstract: OBJECTIVE
  Ketamine is a well-known analgesic and dose-dependent anesthetic used in emergency and disaster medicine. Recently, a new formulation of S-ketamine, as an intranasal spray, was developed and tested in our institution in healthy volunteers. The authors investigated the effect of intranasal S-ketamine spray combined with midazolam intranasal spray in postoperative spinal surgery patients.
  
  
  METHODS
  In this prospective, computer-randomized, double-blinded noninferiority study in spinal surgery patients, the effects of intranasal S-ketamine and midazolam were compared with standard morphine patient-controlled analgesia (PCA). The primary end point was the numeric rating scale pain score 24 hours after surgery.
  
  
  RESULTS
  Twenty-two patients finished this study, eleven in each group. There were similar numeric rating scale scores in the morphine PCA and the S-ketamine-PCA groups at 1, 2, 4, 24, 48, and 72 hours after surgery during rest as well as in motion. There were no differences in the satisfaction scores at any time between the groups. The number of bolus demands and deliveries was not significantly different.
  
  
  CONCLUSIONS
  In our study, we found that an S-ketamine intranasal spray combined with intra-nasal midazolam was similar in effectiveness, satisfaction, number of demands/deliveries of S-ketamine and morphine, and number/severity of adverse events compared with standard intravenous PCA with morphine. S-ketamine can be regarded as an effective alternative for a traditional intravenous morphine PCA in the postoperative setting.
authors.affiliation: Department for Anesthesia, Surgical Intensive Care, Prehospital Emergency Medicine and Pain Therapy, University of Basel, Basel, Switzerland.
authors.forename: Christine
authors.initials: C
authors.lastname: Riediger
authors.affiliation: Clinical Pharmacology, University of Basel, Basel, Switzerland.
authors.forename: Manuel
authors.initials: M
authors.lastname: Haschke
authors.affiliation: Hospital Pharmacy, University of Basel, Basel, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Bitter
authors.affiliation: Clinical Trial Unit, University of Basel, Basel, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Fabbro
authors.affiliation: Orthopedic Department, University Hospital Basel, University of Basel, Basel, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schaeren
authors.affiliation: Department for Anesthesia, Surgical Intensive Care, Prehospital Emergency Medicine and Pain Therapy, University of Basel, Basel, Switzerland.
authors.forename: Albert
authors.initials: A
authors.lastname: Urwyler
authors.affiliation: Department for Anesthesia, Surgical Intensive Care, Prehospital Emergency Medicine and Pain Therapy, University of Basel, Basel, Switzerland.
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Ruppen
keywords: S-ketamine; intranasal; patient-controlled analgesia; postoperative pain