Effects of single shot femoral nerve block combined with intrathecal morphine for postoperative analgesia: a randomized, controlled, dose-ranging study after total knee arthroplasty

Pain after total knee arthroplasty (TKA) is severe, thus adequate pain control can be a challenge. Intrathecal morphine (ITM) provides excellent postoperative analgesia for TKA, but may have side effects. Femoral nerve block (FNB) also has been used for postoperative analgesia in TKA. We examined po...

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Bibliographic Details
Published inJournal of the Medical Association of Thailand Vol. 97; no. 2; p. 195
Main Authors Kunopart, Mutita, Chanthong, Pratamaporn, Thongpolswat, Nimit, Intiyanaravut, Tawan, Pethuahong, Chanyapat
Format Journal Article
LanguageEnglish
Published Thailand 01.02.2014
Subjects
Aged
Analgesics, Opioid - administration & dosage
Arthroplasty, Replacement, Knee
Female
Femoral Nerve
Humans
Injections, Spinal
Male
Middle Aged
Morphine - administration & dosage
Nerve Block - methods
Pain Measurement
Pain, Postoperative - prevention & control
Treatment Outcome
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Summary:Pain after total knee arthroplasty (TKA) is severe, thus adequate pain control can be a challenge. Intrathecal morphine (ITM) provides excellent postoperative analgesia for TKA, but may have side effects. Femoral nerve block (FNB) also has been used for postoperative analgesia in TKA. We examined postoperative analgesia efficacy and side effects of ITM combined with single shot femoral nerve block (SSFNB) after TKA, over the dosage range of 0.0 to 0.3 mg. Sixty patients undergoing elective TKA received SSFNB (0.5% bupivacaine 20 ml) and spinal anesthesia with 15 mg of hyperbaric bupivacaine (0.5% Heavy Marcaine) were included in this study. They were randomized to receive ITM (0, 0.1, 0.2, and 0.3 mg). A patient-controlled analgesia (PCA) device provided additional intravenous morphine. Morphine consumption, pain score, and side effects were recorded at 0, 1, 4, 8, 12, and 24 hour postoperative. Patient satisfaction was rated at the 24-hour postoperative visit. Morphine consumption was significant higher in 0 mg ITM group (control) than other groups, but there was no difference between ITM groups. Pain score was significant lower in 0.3 mg ITM group compared to 0 mg at 1 hour (0.5 vs. 3.5, respectively; p-value = 0.013) and 4 hour (1.5 vs. 4.5, respectively; p-value = 0.037) postoperative period Side effects were not different in all groups. The present study concluded that, low-dose ITM combination with SSFNB provided good pain relief with low side effects and reduced morphine consumption during the first 24 hours post TKA.
ISSN:0125-2208