Presentation on theme: "Intraoperative Small-Dose Ketamine Enhances Analgesia After Outpatient Knee Arthroscopy Elizabeth Mann, RN, BSN, SRNA Oakland University-Beaumont Hospital."— Presentation transcript:
Intraoperative Small-Dose Ketamine Enhances Analgesia After Outpatient Knee Arthroscopy Elizabeth Mann, RN, BSN, SRNA Oakland University-Beaumont Hospital Graduate Program of Nurse Anesthesia February 8, 2012
Article Menigaux, C., Guignard, B., Fletcher, D., Sessler, D.I., Dupont, X., Chauvin, M. (2001). Intraoperative small-dose ketamine enhances analgesia after outpatient knee arthroscopy. Anesthesia & Analgesia 93, 606-12.
Background Ketamine had been previously been tested in inpatient arthroscopic anterior ligament repair proving better pain relief and faster return to normal functional activity Standard treatment for outpatient arthroscopy at the time of study NSAIDs alone Combination with intraarticular Bupivacaine and morphine.
Hypothesis A small intraoperative dose of Ketamine will improve postoperative analgesia and facilitate ambulation after arthroscopic meniscectomy and that the benefits will last for several days.
Study Double blinded study 50 patients: 25 in Control Group and 25 in Ketamine Group Inclusion Criteria: Patients were all scheduled for elective arthroscopic surgery ASA status I and II Between the ages of 18-60
Exclusion Criteria ASA status >II Surgery performed under regional anesthesia History of chronic pain Chronic use of analgesic medications Drug or alcohol abuse Psychiatric disorders Contraindications to NSAIDs
Pain Assessment Tools Verbal rating scale (VRS) and visual analog scale (VAS) while ambulating VAS: 0-100 mm, 0 is no pain and 100 is worst pain VRS: 0= no pain 1= light pain 2= moderate pain 3= intense pain 4= severe pain
Methods Consent was obtained The hospital pharmacist prepared a 10 mL syringe of either isotonic sodium chloride or 0.15 mg/kg Ketamine diluted in isotonic sodium chloride The group assignments were made with a computer generated random number table Patients and OR Staff were unaware of their group assignment
Methods Patients were premedicated with 100mg hydroxyzine PO, 1-2 hours before surgery Induced with Propofol (2mg/kg) followed with Alfentanil (20mcg/kg) LMA inserted Mechanically ventilated GA maintained with Propofol gtt (60-200 mcg/kg/min) Titrated to maintain HR and MAP within 20% of preoperative vitals 60% N2O in oxygen
Methods Same surgeon Same technique Every patient received 20 mL 0.5% Bupivacaine and 5 mg of Morphine injected into knee joint before tourniquet deflation Propofol gtt was discontinued after trocars were removed from the knee
Methods Transferred to PACU 3 mg IV Morphine (every 5 minutes/PRN) until VAS score was <30 mm or VRS score was <2 Patients received 550 mg Naproxen PO Patients were discharged home Instructed to take 550 mg Naproxen twice daily 2 tablets of Di-Antalvic every 6 hours for pain (400 mg Acetaminophen/30 mg dextropropoxyphene) Resume normal activity as soon as they could
Measurements in PACU Pain scores were evaluated at both rest and mobilization Recorded every 15 minutes x 1 hour, then at 2, 4, and 6 hours after surgery Mobilization assessment stopped VAS score >30 mm VRS >2 Sedation score > 2 (patient somnolent, responds to tactile stimulation) HOTN (MAP <60) or Bradycardia (HR <50)
Questionnaires POD 1-3 Assessed pain during the night, at their first step, and an over all rating (VAS) Number of painful events during the day (0-5, 6-10, >10) Duration of walking during that day (0, <1 hour,1-3 hour, or normal) Number of doses of Di-Antalvic and any concomitant medication used during the day Side effects Whether they experienced bad dreams Global score of patient satisfaction with pain control
Data Analysis Primary end point: Post-op pain Secondary end point variables: Analgesic consumption and return to normal walking. Statistical analysis was performed with NCSS 6.0 Unpaired Student T-tests Age, weight, length of surgery, amount of Propofol and Alfentanil Time intervals to SV, LMA removal, arrival to PACU, and discharge home
Data Analysis Mann-Whitney U-test Analgesic doses, sedation scores, and pain episodes X2 Frequency of side effects Results presented as +/- SD or median and 25-75 th percentile ranges P< 0.05 was considered statistically significant
Results Control group required more Morphine titration in PACU (P<0.05) Ketamine group had lower VAS scores in PACU while ambulating Pain scores were lower in the Ketamine group (POD 1-3) During the night At their first step During ambulation Ketamine group required less additional narcotic (POD1- 3) There were no reports of N/V, dysphoria, hallucinations, diplopia, cognitive or memory impairments in both groups
Strengths/Limitations Strengths No patients were excluded All 50 patients returned the follow up questionnaire Double Blind Study Limitations Small sample size Difficult to study pain due to subjective measurements
Conclusion This study extended previous studies that evaluated small dose ketamine benefits for inpatient orthopedic procedures. It provided evidence that a balanced technique with Ketamine could provide better analgesia and improve ambulation without increasing adverse effects.