Use of a drug named dexmedetomidine with local anaesthesia drug for middle thigh block in patients undergoing knee ligament surgeries and its effect on requirement of post operative pain relieving drug.

Not Applicable

Completed

• Conditions: Patients undergoing knee ligament reconstruction surgeries

• Registration Number: CTRI/2016/03/006712
• Lead Sponsor: Govt Medical College And Hospital

Brief Summary

Regional nerve blocks provide longer duration of analgesia and are efficient in preventing sensitization of the central and peripheral nervous system, which may prevent the development of chronic pain. Patients after arthroscopic ACL reconstruction experience moderate to severe pain in the postoperative period. There are various modalities for postoperative pain control after arthroscopic ACL reconstruction such as systemic analgesics (non-opioids and opioids), intra-articular analgesics, neuraxial blocks and peripheral nerve blockade. One such technique is adductor canal block (ACB) of the saphenous nerve. ACB involves injection of local anaesthetic into the adductor canal deep to the sartorius muscle.  The local anaesthetic then spreads throughout the adductor canal around the saphenous nerve resulting in sensory analgesia of its dermatomal distribution without any appreciable motor block.

Dexmedetomidine is a highly selective alpha 2 agonist acting through centrally mediated mechanism, having analgesic, anxiolytic, haemodynamic, sedative, and anaesthetic sparing effects. Due to its central sympatholytic effect, dexmedetomidine is useful in blunting haemodynamic responses in perioperative period. The peripheral actions of dexmedetomidine are mediated through post synaptic alpha 2a receptors. It causes local vasoconstriction, thus decreasing local anaesthetic spread and removal of local anaesthetic around the neural structures.

Dexmedetomidine as adjuvant to local anaesthetic in peripheral nerve blocks has shown to shorten the sensory block onset time and extend the duration of analgesia . In a recently published study by Keplinger et al, it was concluded that dexmedetomidine mixed with ropivacaine produces a dose dependent prolongation of sensory analgesia when used in ulnar nerve block. So far, there has been no randomized controlled trial to study the analgesic effect of dexmedetomidine as adjuvant to local anaesthetic ropivacaine in saphenous nerve block. The present study is planned to evaluate the efficacy of ultrasound guided ACB with local anaesthetic ropivacaine and dexmedetomidine as adjuvant in prolonging the duration of analgesia after ACB following arthroscopic ACL reconstruction surgery.

Sample size calculation-

Sample size was calculated on the basis of few pilot cases conducted in the department of Anaesthesia and Intensive Care, Government Medical College and Hospital, Chandigarh. It was observed that the mean opioid consumption in the patients receiving dexmedetomidine and ropivacaine with the ACB was 5mg with a standard deviation of 4.08 and intravenously was 5.25mg with a standard deviation of 3.4. In the control group patients receiving ropivacaine in the ACB catheter, the mean opioid consumption was 8.25mg with a standard deviation of 4.72. The sample size came out to be 29 patients per group at a power of 80% and confidence interval of 95%. To compensate for drop-outs, we decided to include 35 patients per group. So, the total sample size of our study will be 105 patients.

Results: The mean postoperative morphine consumption was significantly reduced till 4 hours in Group II 0.57 mg (0.98 [0-3]) (p = 0.011) and up to 6 hours in Group III 0.77 mg (1.00 [0-4]) (p = 0.004) compared to control group. The mean postoperative morphine consumption was comparable at 24 hours in Group III 3.57 mg (1.73 [0-8]) and Group II 3.34mg (1.92 [0-7]) (p = 1.000). The time to first analgesic request was significantly prolonged in group III 8.57 h (4.98) compared to group I 4.43 h (5.54) and group II 7.14 h (4.83) (p < 0.001). The VAS scores were comparable in all the three groups at all the time intervals studied (p > 0.05). The strength of the quadriceps muscle was well preserved, there were no significant differences in range of movement (p = 0.387) and timed-up-and-go tests (p = 0.469) between all the three groups at 24 hours postoperatively. There were no adverse effects i.e. hypotension or bradycardia observed during the study. The Ramsay Sedation Score (RSS) was significantly higher in group III 2.49 (0.74 [2-4]) as compared to group I 2.09 (0.28 [2-3]) and group II 2.09 (0.28 [2-3]) till 20 min postoperatively (p = 0.003).

Conclusion:  Postoperative morphine consumption was significantly reduced up to 4 h with perineural dexmedetomidine and up to 6 h with IV dexmedetomidine in patients undergoing arthroscopic ACL reconstruction surgeries.

Detailed Description

Not available

Study Timeline

• Study Start: 2016-10-03
• Last Update Posted: 2018-07-03
• Study Completion: 2018-10-02

Recruitment & Eligibility

• Status: Completed
• Sex: All
• Target Recruitment: 105

Inclusion Criteria

• ASA physical status I and II of either sex 2.
• Age between 18 to 60 years 3.
• BMI ≥ 20 to ≤ 30 kg m-2 4.
• Scheduled for ACL reconstruction surgery.

Exclusion Criteria

• Patients having history of substance abuse.
• Patients with coagulopathy and bleeding disorders.
• Preexisting peripheral neuropathy.
• Preexisting local infection at the site of block.
• Pregnant and lactating women.
• Inability to understand functioning of PCA pump and VAS (Visual Analogue Scale).
• Contraindication to study drugs ropivacaine, dexmedetomidine and morphine.
• Patients having haemodynamic instability, hypotension, bradycardia, hepatic dysfunction.
• Patients on regular chronic pain management drugs for the last three months.

Study & Design

• Study Type: Interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
To study morphine sparing effect of dexmedetomidine as adjuvant to ropivacaine in ultrasound guided ACB following arthroscopic ACL reconstruction surgery.	To study cumulative morphine consumption at 24 hours. Morphine consumption will be monitored at 0,2,4,6,8,12 and 24 hours interval.

Secondary Outcome Measures

Name	Time	Method
To study postoperative pain relief, haemodynamics and adverse effects after ultrasound guided ACB following arthroscopic ACL reconstruction surgery.	Preoperatively (baseline),immediately after block 0, 5, 10, 15, 20, 30, 60 minutes and followed by 2, 4, 6, 8, 12 and 24 hours interval.

Trial Locations

Locations (1)

Govt Medical College and Hospital; 🇮🇳 Chandigarh, CHANDIGARH, India

Govt Medical College and Hospital

🇮🇳Chandigarh, CHANDIGARH, India

Dr Deepak Thapa

Principal investigator

9646121524

dpkthapa@gmail.com