The Effect of Perioperative Ketamine on Acute and Chronic Pain After Major Back Surgery

Summary

After a surgical operation, patients may suffer from chronic pain. Ketamine, a well known anesthetic acts on receptors in the spine (NMDA receptors), which are implied in the occurrence of chronic pain. The mechanism is called central sensation. It is known that Ketamine reduces immediate postoperative pain, but its effectiveness in the prevention of the chronic pain is still unknown. The investigators study will follow patients until one year after operation for the occurrence of chronic pain. The investigators hypothesis is that Ketamine reduces significantly chronic postoperative pain after major back surgery and improves patient outcome.

There may be important inter-individual differences how persons react on a drug. These differences are partly determined by the genes of each individual. The investigators study includes therefore a genetic analysis.

Psychological and social factors also influence the perception of pain. It is still not well understood who these "psychosocial factors" determine the appearance and perception of chronic pain. In the investigators study the investigators will therefore study these factors by questionnaires.

Conditions

• Postoperative Pain

Interventions

DRUG

Placebo

50 ml syringes provided by the HUG pharmacy will contain 1% ketamine or 0.9% NaCl. After induction and before start of surgery, patients will receive an intravenous bolus of 0.025 ml/kg of the study solution (corresponding to 0.25 mg/kg ketamine). Maintenance will be with a syringe driver at a rate of 0.025 ml/kg/h (corresponding to 0.25 mg/kg/h ketamine) until one hour before the end of surgery, and will then be decreased to a rate of 0.01 ml/kg/h (corresponding to 0.1 mg/kg/h ketamine) throughout the stay in the recovery room (usually 2 to 3 hours). The infusion will be stopped when the patient leaves the recovery room.

DRUG

Ketamine

50 ml syringes provided by the HUG pharmacy will contain 1% ketamine or 0.9% NaCl. After induction and before start of surgery, patients will receive an intravenous bolus of 0.025 ml/kg of the study solution (corresponding to 0.25 mg/kg ketamine). Maintenance will be with a syringe driver at a rate of 0.025 ml/kg/h (corresponding to 0.25 mg/kg/h ketamine) until one hour before the end of surgery, and will then be decreased to a rate of 0.01 ml/kg/h (corresponding to 0.1 mg/kg/h ketamine) throughout the stay in the recovery room (usually 2 to 3 hours). The infusion will be stopped when the patient leaves the recovery room.

Sponsors & Collaborators

• University Hospital, Geneva

  lead OTHER

Principal Investigators

• Martin Tramèr, Prof, MD, PhD · anesthesia department

• Christoph A Czarnetzki, MD, MBA · anesthesia department

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

QUADRUPLE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2007-10-31

Primary Completion

2013-03-31

Completion

2013-03-31

Countries

• Switzerland

Study Locations