Epidural Morphine for Postoperative Analgesia After Total Knee Arthroplasty

Peking University

Status: Completed

Conditions: Adult Patients; Femoral Nerve Block; Epidural Analgesia; Total Knee Arthroplasty; Analgesic Adverse Reaction

Treatments: Procedure: Single femoral nerve block; Drug: Intravenous morphine analgesia; Procedure: Epidural morphine; Procedure: Epidural placebo

Study type: Interventional

Funder types: Other

Identifiers

NCT03203967

2017[1308]

Details and patient eligibility

About

Single femoral nerve blockade combined with patient-controlled intravenous analgesia are used for postoperative analgesia for patients after TKA in the hospital of the investigators. Although this method provides acceptable analgesia, the incidence of opioid-associated side effects is relatively high. Low-dose epidural morphine is commonly used in postoperative analgesia after cesarean section, and the effect of single dose morphine lasts more than 20 hours, with low incidences of itching, nausea, vomiting, and respiratory depression. The investigators hypothesize that, for patients undergoing TKA, the addition of low-dose epidural morphine to single femoral nerve block and intravenous opioids can improve the postoperative analgesia, reduce the consumption of intravenous opioids and decrease opioid-associated side effects.

Full description

Total knee arthroplasty (TKA) is an important therapy for patients with serious knee osteoarthritis in order to improve quality of life and relieve pain. But a large number of patients who undergo this surgery experience moderate to severe postoperative pain. Previously, the investigators used single femoral nerve blockade combined with patient-controlled intravenous analgesia for postoperative analgesia for patients after TKA. Although this method provides acceptable analgesia, the incidence of opioid-associated side effects is relatively high. Low-dose epidural morphine is commonly used in postoperative analgesia after cesarean section, and the effect of single dose morphine lasts more than 20 hours, with low incidences of itching, nausea, vomiting, and respiratory depression. The investigators hypothesize that, for patients undergoing TKA, the addition of low-dose epidural morphine to single femoral nerve block and intravenous opioids can improve the postoperative analgesia, reduce the consumption of intravenous opioids and decrease opioid-associated side effects.

Enrollment: 110 patients

Sex: All

Ages: 18 to 90 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Adult patients (age of 18 years or older);
• American Society of Anesthesiologists classification I-III;
• Scheduled to undergo unilateral TKA under combined spinal and epidural anesthesia.

Exclusion criteria

• Age higher than 90 years old;
• Presence of any contraindication to neuraxial block or peripheral nerve block;
• Continuous use of opioid analgesics during the last month;
• Unable to understand Numeric Rating Scale for pain evaluation or existence of language barrier;
• Severe renal insufficiency (requirement of renal replacement therapy);
• History of asthma;
• Recruited in another clinical trials.

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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110 participants in 2 patient groups, including a placebo group

Epidural morphine

Experimental group

Description:

1. Epidural morphine (2 mg morphine in 5 ml normal saline) is administered through the epidural catheter at the end of surgery. 2. Single femoral nerve block is performed with 20 ml of 0.5% ropivacaine under the guidance of ultrasonography and nerve stimulator after surgery. 3. Intravenous morphine analgesia is provided with a patient-controlled analgesia pump which is established with 100 ml of 0.5 mg/mL morphine, programmed to deliver a 2 ml bolus with a lockout interval of 8-10 min and a background infusion of 0.5 mL/h.

Treatment:

Drug: Intravenous morphine analgesia

Procedure: Single femoral nerve block

Procedure: Epidural morphine

Epidural placebo

Placebo Comparator group

Description:

1. Epidural placebo (5 ml normal saline) is administered through the epidural catheter at the end of surgery. 2. Single femoral nerve block is performed with 20 ml of 0.5% ropivacaine under the guidance of ultrasonography and nerve stimulator after surgery. 3. Intravenous morphine analgesia is provided with a patient-controlled analgesia pump which is established with 100 ml of 0.5 mg/mL morphine, programmed to deliver a 2 ml bolus with a lockout interval of 8-10 min and a background infusion of 0.5 mL/h.

Treatment:

Drug: Intravenous morphine analgesia

Procedure: Single femoral nerve block

Procedure: Epidural placebo