<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT02241278</url>
  </required_header>
  <id_info>
    <org_study_id>MK334037</org_study_id>
    <nct_id>NCT02241278</nct_id>
  </id_info>
  <brief_title>Preoperative Ketamine Has no Preemptive Analgesic Effect in Patients Undergoing Colon Surgery.</brief_title>
  <official_title>Preoperative Low-dose Ketamine Has no Preemptive Analgesic Effect in Opioid-naïve Patients Undergoing Colon Surgery When Nitrous Oxide is Used</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Hospital Arquitecto Marcide</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
    <collaborator>
      <agency>Complexo Hospitalario Universitario de A Coruña</agency>
      <agency_class>Other</agency_class>
    </collaborator>
  </sponsors>
  <source>Hospital Arquitecto Marcide</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      The analgesic properties of ketamine are associated with its non-competitive antagonism of&#xD;
      the N-methyl-D-aspartate receptor; these receptors exhibit an excitatory function on pain&#xD;
      transmission and this binding seems to inhibit or reverse the central sensitization of pain.&#xD;
      In the literature, the value of this anesthetic for preemptive analgesia in the control of&#xD;
      postoperative pain is uncertain. The objective of this study was to ascertain whether&#xD;
      preoperative low-dose ketamine reduces postoperative pain and morphine consumption in adults&#xD;
      undergoing colon surgery.&#xD;
&#xD;
      In a double-blind, randomized trial, 48 patients were studied. Patients in the ketamine group&#xD;
      received 0.5 mg/kg intravenous ketamine before surgical incision, while the control group&#xD;
      received normal saline. The postoperative analgesia was achieved with a continuous infusion&#xD;
      of morphine at 0.015 mg∙kgˉ¹∙hˉ¹ with the possibility of 0.02 mg/kg bolus every 10 min. Pain&#xD;
      was assessed using the Visual Analog Scale (VAS), morphine consumption, and hemodynamic&#xD;
      parameters at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively. We quantified times to&#xD;
      rescue analgesic (Paracetamol), adverse effects and patient satisfaction.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      In spite of the techniques we have at our disposal and the elementary nature of incisional&#xD;
      pain, optimal pain management remains a challenge. Because the severity of early&#xD;
      postoperative pain relates to residual pain after some types of surgery, perioperative pain&#xD;
      management can considerably influence the long-term quality of life in patients.&#xD;
&#xD;
      Woolf, in 1983, first introduced the theory of preemptive analgesia to attenuate&#xD;
      postoperative pain, confirming the presence of a central factor of post-injury pain&#xD;
      hypersensitivity in experimental research. After this, experimental studies showed that&#xD;
      various anti-nociceptive methods applied before injuries were more effective in reducing&#xD;
      post-injury central sensitization in contrast to administration after injury.&#xD;
&#xD;
      After activation of C-fibers by noxious stimuli, sensory neurons become more sensitive to&#xD;
      peripheral inputs, a process called central sensitization. 'Wind up, another mechanism&#xD;
      activating spinal sensory neurons, is seen after reiterated stimulation of C-fibers. These&#xD;
      sensitizations produce c-fos expression in sensory neurons, and are related to the activation&#xD;
      of N-methyl-D-aspartic acid (NMDA) and neurokinin receptors. These genes produce long-lasting&#xD;
      changes in the pain-processing system, resulting in hyperexcitation. According to Wall,&#xD;
      protection of sensory neurons against central sensitization may provide relief from pain&#xD;
      after surgery. Based on this assumption, preemptive analgesia has been recommended as an&#xD;
      effective aid to control postsurgical pain. NMDA antagonists have been demonstrated to block&#xD;
      the induction of central sensitization and revoke the hypersensitivity once it is&#xD;
      established.&#xD;
&#xD;
      Ketamine is an old drug that is increasingly being considered for the treatment of acute and&#xD;
      chronic pain. Its pharmacology and mechanism of action as an NMDA receptor antagonist are&#xD;
      adequately known, but in clinical practice it presents irregular results. Since ketamine is&#xD;
      an NMDA-receptor antagonist, it is supposed to avoid or revoke central sensitization, and&#xD;
      thus to attenuate postoperative pain.&#xD;
&#xD;
      This antihyperalgesic action can be achieved by smaller doses than those required for&#xD;
      anesthesia. Small-dose ketamine has been specified as not more than 1 mg/kg when given as an&#xD;
      iv bolus, and not higher than 20 µg∙kgˉ¹∙minˉ¹ when given as a constant infusion.&#xD;
&#xD;
      Low-doses preemptive ketamine administered iv seem to reduce postoperative pain and/or&#xD;
      analgesic consumption. According to one study, a single dose of ketamine 1 mg/kg, when&#xD;
      administered in conjunction with local anesthetics, opioids or other anesthetics, provides&#xD;
      good postoperative pain control.&#xD;
&#xD;
      Regardless of the overwhelming effectiveness of preemptive ketamine in animal experiments,&#xD;
      clinical reports are mixed; some authors have described positive effects while others have&#xD;
      not.&#xD;
&#xD;
      While early reviews of clinical findings were mostly contradictory, there is still conviction&#xD;
      in the effectiveness of preemptive analgesia.&#xD;
&#xD;
      To our knowledge, no prior controlled study has determined the effectiveness of preoperative&#xD;
      low-dose iv ketamine as contrasted with placebo in adults after open colon surgery. Thus,&#xD;
      this clinical trial was designed to examine the postoperative analgesic effectiveness and&#xD;
      opioid-sparing effect of single low-dose iv ketamine in contrast with placebo administered&#xD;
      preoperatively.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date>September 2001</start_date>
  <completion_date type="Actual">June 2002</completion_date>
  <primary_completion_date type="Actual">June 2002</primary_completion_date>
  <phase>Phase 4</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Randomized</allocation>
    <intervention_model>Parallel Assignment</intervention_model>
    <primary_purpose>Prevention</primary_purpose>
    <masking>Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Visual Analog Scale (VAS) score</measure>
    <time_frame>at 0 hours postoperatively (arrival at recovery room)</time_frame>
    <description>The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).</description>
  </primary_outcome>
  <primary_outcome>
    <measure>Visual Analog Scale (VAS) score</measure>
    <time_frame>at 1 hour postoperatively</time_frame>
    <description>The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).</description>
  </primary_outcome>
  <primary_outcome>
    <measure>Visual Analog Scale (VAS) score</measure>
    <time_frame>at 2 hours postoperatively</time_frame>
    <description>The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).</description>
  </primary_outcome>
  <primary_outcome>
    <measure>Visual Analog Scale (VAS) score</measure>
    <time_frame>at 4 hours postoperatively</time_frame>
    <description>The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).</description>
  </primary_outcome>
  <primary_outcome>
    <measure>Visual Analog Scale (VAS) score</measure>
    <time_frame>at 8 hours postoperatively</time_frame>
    <description>The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).</description>
  </primary_outcome>
  <primary_outcome>
    <measure>Visual Analog Scale (VAS) score</measure>
    <time_frame>at 12 hours postoperatively</time_frame>
    <description>The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).</description>
  </primary_outcome>
  <primary_outcome>
    <measure>Visual Analog Scale (VAS) score</measure>
    <time_frame>at 16 hours postoperatively</time_frame>
    <description>The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).</description>
  </primary_outcome>
  <primary_outcome>
    <measure>Visual Analog Scale (VAS) score</measure>
    <time_frame>at 24 hours postoperatively</time_frame>
    <description>The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>morphine consumption</measure>
    <time_frame>at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively</time_frame>
    <description>The cumulative amounts of morphine (mg) administered through the Patient-Controlled-Analgesia (PCA) device as a basal infusion and the incremental supplemental bolus required by the patient were documented at these time points.</description>
  </secondary_outcome>
  <other_outcome>
    <measure>Blood Pressure (BP) systolic</measure>
    <time_frame>at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively</time_frame>
    <description>Measured in mm Hg. We evaluated these hemodynamic parameters as an indirect measure of pain.</description>
  </other_outcome>
  <other_outcome>
    <measure>Blood Pressure (BP) diastolic</measure>
    <time_frame>at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively</time_frame>
    <description>Measured in mm Hg. We evaluated these hemodynamic parameters as an indirect measure of pain</description>
  </other_outcome>
  <other_outcome>
    <measure>Heart rate</measure>
    <time_frame>at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively.</time_frame>
    <description>We evaluated these hemodynamic parameters as an indirect measure of pain</description>
  </other_outcome>
  <other_outcome>
    <measure>Respiratory rate</measure>
    <time_frame>at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively.</time_frame>
    <description>We evaluated these hemodynamic parameters as an indirect measure of pain.</description>
  </other_outcome>
  <other_outcome>
    <measure>Time for the first demand of analgesia</measure>
    <time_frame>24 h postoperatively.</time_frame>
    <description>The time interval to first solicited rescue analgesia in the 24 h postoperatively (in minutes). This rescue analgesia was administered if the established analgesic treatment was not sufficient to alleviate pain.</description>
  </other_outcome>
  <other_outcome>
    <measure>Number of rescue doses</measure>
    <time_frame>24 h postoperatively</time_frame>
    <description>The number of times a rescue analgesic dose was administered as a supplement in the first postoperative 24 hours.</description>
  </other_outcome>
  <other_outcome>
    <measure>Satisfaction score</measure>
    <time_frame>24 hours postoperatively</time_frame>
    <description>Global patient satisfaction (0-3), regarding pain control, was measured 24 hours after the operation</description>
  </other_outcome>
  <other_outcome>
    <measure>Side effects</measure>
    <time_frame>24 hours postoperatively</time_frame>
    <description>Number of Participants with Serious and Non-Serious Adverse Events in the 24 hours postoperatively</description>
  </other_outcome>
  <number_of_arms>2</number_of_arms>
  <enrollment type="Actual">48</enrollment>
  <condition>Pain, Postoperative</condition>
  <arm_group>
    <arm_group_label>Control</arm_group_label>
    <arm_group_type>Placebo Comparator</arm_group_type>
    <description>In the operating room, the anesthesiologist administered 50 mL of 0.9% saline intravenously to patients in the control group 30 minutes before surgical incision.</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Ketamine</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>In the operating room, the anesthesiologist administered 0.5 mg/kg of ketamine chlorhydrate in 50 mL of 0.9 % saline intravenously to patients in the ketamine group 30 minutes before surgical incision. (a single dose).</description>
  </arm_group>
  <intervention>
    <intervention_type>Drug</intervention_type>
    <intervention_name>Ketamine</intervention_name>
    <description>In the operating room, the anesthesiologist administered 0.5 mg/kg of ketamine chlorhydrate in 50 mL of 0.9 % saline intravenously to patients in the ketamine group 30 minutes before surgical incision (a single dose).</description>
    <arm_group_label>Ketamine</arm_group_label>
    <other_name>ketamine chlorhydrate</other_name>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  age between 18 and 75 years&#xD;
&#xD;
          -  normal Body Mass Index (18.5 - 24.9)&#xD;
&#xD;
          -  American Society of Anesthesiologists (ASA) class I, II or III&#xD;
&#xD;
          -  elective surgery&#xD;
&#xD;
          -  surgery time between 60-150 min&#xD;
&#xD;
          -  understanding of the Visual Analog Scale (VAS)&#xD;
&#xD;
          -  lack of allergies or intolerance to anesthetics&#xD;
&#xD;
          -  absence of psychiatric illness&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  cognitive deterioration&#xD;
&#xD;
          -  inability to use the Patient-Controlled-Analgesia (PCA) device&#xD;
&#xD;
          -  history of chronic pain syndromes&#xD;
&#xD;
          -  chronic use of analgesics, sedatives, opioids or steroids&#xD;
&#xD;
          -  liver or hematologic disease,&#xD;
&#xD;
          -  history of drug or alcohol abuse&#xD;
&#xD;
          -  intolerance to ketamine or Paracetamol.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>75 Years</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Manuel Camba Rodriguez, M.D.</last_name>
    <role>Study Chair</role>
    <affiliation>Hospital Arquitecto Marcide</affiliation>
  </overall_official>
  <overall_official>
    <last_name>Beatriz Nistal Nuno, M.D.</last_name>
    <role>Principal Investigator</role>
    <affiliation>Complexo Hospitalario Universitario A Coruna</affiliation>
  </overall_official>
  <overall_official>
    <last_name>Enrique Freire-Vila, M.D.</last_name>
    <role>Study Director</role>
    <affiliation>Complexo Hospitalario Universitario A Coruna</affiliation>
  </overall_official>
  <overall_official>
    <last_name>Francisco Castro Seoane, M.D.</last_name>
    <role>Principal Investigator</role>
    <affiliation>Hospital Arquitecto Marcide</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Hospital Arquitecto Marcide</name>
      <address>
        <city>Ferrol</city>
        <state>A Coruna</state>
        <zip>15405</zip>
        <country>Spain</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Spain</country>
  </location_countries>
  <verification_date>September 2014</verification_date>
  <study_first_submitted>September 11, 2014</study_first_submitted>
  <study_first_submitted_qc>September 15, 2014</study_first_submitted_qc>
  <study_first_posted type="Estimate">September 16, 2014</study_first_posted>
  <last_update_submitted>September 15, 2014</last_update_submitted>
  <last_update_submitted_qc>September 15, 2014</last_update_submitted_qc>
  <last_update_posted type="Estimate">September 16, 2014</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Complexo Hospitalario Universitario de A Coruña</investigator_affiliation>
    <investigator_full_name>Beatriz Nistal Nuno</investigator_full_name>
    <investigator_title>M.D.</investigator_title>
  </responsible_party>
  <keyword>colon surgery</keyword>
  <keyword>ketamine</keyword>
  <keyword>patient-controlled-analgesia</keyword>
  <keyword>preemptive analgesia</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Pain, Postoperative</mesh_term>
  </condition_browse>
  <intervention_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Ketamine</mesh_term>
  </intervention_browse>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT02241278
org study id: MK334037
nct id: NCT02241278
lead sponsor: 
collaborator: 
has dmc: No
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 uncertain. The objective of this study was to ascertain whether
      preoperative low-dose ketamine reduces postoperative pain and morphine consumption in adults
      undergoing colon surgery.

      In a double-blind, randomized trial, 48 patients were studied. Patients in the ketamine group
      received 0.5 mg/kg intravenous ketamine before surgical incision, while the control group
      received normal saline. The postoperative analgesia was achieved with a continuous infusion
      of morphine at 0.015 mg∙kgˉ¹∙hˉ¹ with the possibility of 0.02 mg/kg bolus every 10 min. Pain
      was assessed using the Visual Analog Scale (VAS), morphine consumption, and hemodynamic
      parameters at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively. We quantified times to
      rescue analgesic (Paracetamol), adverse effects and patient satisfaction.
In spite of the techniques we have at our disposal and the elementary nature of incisional
      pain, optimal pain management remains a challenge. Because the severity of early
      postoperative pain relates to residual pain after some types of surgery, perioperative pain
      management can considerably influence the long-term quality of life in patients.

      Woolf, in 1983, first introduced the theory of preemptive analgesia to attenuate
      postoperative pain, confirming the presence of a central factor of post-injury pain
      hypersensitivity in experimental research. After this, experimental studies showed that
      various anti-nociceptive methods applied before injuries were more effective in reducing
      post-injury central sensitization in contrast to administration after injury.

      After activation of C-fibers by noxious stimuli, sensory neurons become more sensitive to
      peripheral inputs, a process called central sensitization. 'Wind up, another mechanism
      activating spinal sensory neurons, is seen after reiterated stimulation of C-fibers. These
      sensitizations produce c-fos expression in sensory neurons, and are related to the activation
      of N-methyl-D-aspartic acid (NMDA) and neurokinin receptors. These genes produce long-lasting
      changes in the pain-processing system, resulting in hyperexcitation. According to Wall,
      protection of sensory neurons against central sensitization may provide relief from pain
      after surgery. Based on this assumption, preemptive analgesia has been recommended as an
      effective aid to control postsurgical pain. NMDA antagonists have been demonstrated to block
      the induction of central sensitization and revoke the hypersensitivity once it is
      established.

      Ketamine is an old drug that is increasingly being considered for the treatment of acute and
      chronic pain. Its pharmacology and mechanism of action as an NMDA receptor antagonist are
      adequately known, but in clinical practice it presents irregular results. Since ketamine is
      an NMDA-receptor antagonist, it is supposed to avoid or revoke central sensitization, and
      thus to attenuate postoperative pain.

      This antihyperalgesic action can be achieved by smaller doses than those required for
      anesthesia. Small-dose ketamine has been specified as not more than 1 mg/kg when given as an
      iv bolus, and not higher than 20 µg∙kgˉ¹∙minˉ¹ when given as a constant infusion.

      Low-doses preemptive ketamine administered iv seem to reduce postoperative pain and/or
      analgesic consumption. According to one study, a single dose of ketamine 1 mg/kg, when
      administered in conjunction with local anesthetics, opioids or other anesthetics, provides
      good postoperative pain control.

      Regardless of the overwhelming effectiveness of preemptive ketamine in animal experiments,
      clinical reports are mixed; some authors have described positive effects while others have
      not.

      While early reviews of clinical findings were mostly contradictory, there is still conviction
      in the effectiveness of preemptive analgesia.

      To our knowledge, no prior controlled study has determined the effectiveness of preoperative
      low-dose iv ketamine as contrasted with placebo in adults after open colon surgery. Thus,
      this clinical trial was designed to examine the postoperative analgesic effectiveness and
      opioid-sparing effect of single low-dose iv ketamine in contrast with placebo administered
      preoperatively.
allocation: Randomized
intervention model: Parallel Assignment
primary purpose: Prevention
masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
measure: Visual Analog Scale (VAS) score
time frame: at 0 hours postoperatively (arrival at recovery room)
description: The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).
measure: Visual Analog Scale (VAS) score
time frame: at 1 hour postoperatively
description: The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).
measure: Visual Analog Scale (VAS) score
time frame: at 2 hours postoperatively
description: The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).
measure: Visual Analog Scale (VAS) score
time frame: at 4 hours postoperatively
description: The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).
measure: Visual Analog Scale (VAS) score
time frame: at 8 hours postoperatively
description: The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).
measure: Visual Analog Scale (VAS) score
time frame: at 12 hours postoperatively
description: The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).
measure: Visual Analog Scale (VAS) score
time frame: at 16 hours postoperatively
description: The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).
measure: Visual Analog Scale (VAS) score
time frame: at 24 hours postoperatively
description: The VAS represents a scale with the lowest value as 0 (no pain) and the highest value as 10 (worst imaginable pain).
measure: morphine consumption
time frame: at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively
description: The cumulative amounts of morphine (mg) administered through the Patient-Controlled-Analgesia (PCA) device as a basal infusion and the incremental supplemental bolus required by the patient were documented at these time points.
measure: Blood Pressure (BP) systolic
time frame: at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively
description: Measured in mm Hg. We evaluated these hemodynamic parameters as an indirect measure of pain.
measure: Blood Pressure (BP) diastolic
time frame: at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively
description: Measured in mm Hg. We evaluated these hemodynamic parameters as an indirect measure of pain
measure: Heart rate
time frame: at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively.
description: We evaluated these hemodynamic parameters as an indirect measure of pain
measure: Respiratory rate
time frame: at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively.
description: We evaluated these hemodynamic parameters as an indirect measure of pain.
measure: Time for the first demand of analgesia
time frame: 24 h postoperatively.
description: The time interval to first solicited rescue analgesia in the 24 h postoperatively (in minutes). This rescue analgesia was administered if the established analgesic treatment was not sufficient to alleviate pain.
measure: Number of rescue doses
time frame: 24 h postoperatively
description: The number of times a rescue analgesic dose was administered as a supplement in the first postoperative 24 hours.
measure: Satisfaction score
time frame: 24 hours postoperatively
description: Global patient satisfaction (0-3), regarding pain control, was measured 24 hours after the operation
measure: Side effects
time frame: 24 hours postoperatively
description: Number of Participants with Serious and Non-Serious Adverse Events in the 24 hours postoperatively
arm group label: Control
arm group type: Placebo Comparator
description: In the operating room, the anesthesiologist administered 50 mL of 0.9% saline intravenously to patients in the control group 30 minutes before surgical incision.
arm group label: Ketamine
arm group type: Experimental
description: In the operating room, the anesthesiologist administered 0.5 mg/kg of ketamine chlorhydrate in 50 mL of 0.9 % saline intravenously to patients in the ketamine group 30 minutes before surgical incision. (a single dose).
intervention type: Drug
intervention name: Ketamine
description: In the operating room, the anesthesiologist administered 0.5 mg/kg of ketamine chlorhydrate in 50 mL of 0.9 % saline intravenously to patients in the ketamine group 30 minutes before surgical incision (a single dose).
arm group label: Ketamine
other name: ketamine chlorhydrate
criteria: 
gender: All
minimum age: 18 Years
maximum age: 75 Years
healthy volunteers: No
last name: Manuel Camba Rodriguez, M.D.
role: Study Chair
affiliation: Hospital Arquitecto Marcide
last name: Beatriz Nistal Nuno, M.D.
role: Principal Investigator
affiliation: Complexo Hospitalario Universitario A Coruna
last name: Enrique Freire-Vila, M.D.
role: Study Director
affiliation: Complexo Hospitalario Universitario A Coruna
last name: Francisco Castro Seoane, M.D.
role: Principal Investigator
affiliation: Hospital Arquitecto Marcide
facility: 
country: Spain
responsible party type: Principal Investigator
investigator affiliation: Complexo Hospitalario Universitario de A Coruña
investigator full name: Beatriz Nistal Nuno
investigator title: M.D.
mesh term: Pain, Postoperative
mesh term: Ketamine