Sciatic lateral popliteal block with clonidine alone or clonidine plus 0.2% ropivacaine: effect on the intra- and postoperative analgesia for lower extremity surgery in children, a randomised prospective controlled study
Our hypothesis was that clonidine alone or combined with 0.2% ropivacaine could produce a long lasting sciatic lateral popliteal block (SLPB) after foot and ankle surgery, adequate for the first postoperative day.
Scientific Ethics Committee of General Children's Hospital, Penteli, Athens approved on 20/05/2008
Single-centre interventional prospective randomised controlled study
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
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Disturbances of Achilles tendon and club foot
Between January 2009 to May 2010, 77 consecutive children, American Society of Anesthesiologists (ASA) physical status I and II, aged 5-14 years were scheduled for elective mild to moderate painful foot and ankle surgery.
66 children were randomly assigned to three groups by means of a computer generated table to receive either isotonic saline (n=21) or clonidine (n =23) or clonidine plus 0.2% ropivacaine (n=22), during performance of a sciatic lateral popliteal block (SLPB) plus femoral block. The investigators were blind to the group assignment. The placebo or the treatment solutions were prepared by the pharmacy and supplied to the Department of Anaesthesia in syringes labelled with predetermined code for each solution. There were two syringes for the SLPB and the femoral block respectively.
In the SLPB, the syringes contained
1. For the control group isotonic saline 10 ml plus 0.25 ml/kg and saline 0.13 ml/kg
2. For the clonidine group isotonic saline 10 ml plus 0.25 ml/kg and clonidine 2 µg/kg (0.13 ml/kg) respectively
3. Finally in the clonidine plus 0.2% ropivacaine group the syringes contained 0.2% ropivacaine 10 ml plus 0.25 ml/kg (maximum 25 ml) and clonidine 2 µg/kg (0.13 ml/kg) respectively.
Similarly in the femoral block the syringes contained
1. For the control group isotonic saline: 0.4 ml/kg and 0.065 ml/kg respectively
2. For the clonidine group isotonic saline 0.4 ml/kg and clonidine 1µg/kg (0.065 ml/kg) respectively
3. For clonidine plus 0.2% ropivacaine group 0.2% ropivacaine 0.4 ml/kg and clonidine 1µg/kg (0.065 ml/kg) respectively. The maximum dose of 0.2% ropivacaine was decided to be 3.5 mg/kg and for clonidine 3 µg/kg.
In the anaesthetised children in the supine position, the SLPB was performed, using 100 mm or 50 mm, 21 gauge insulated stimulated needle. An additional femoral block became necessary for the use of tourniquet in the area around the thigh. After the performance of blocks a pneumatic tourniquet at 150 mmHg was applied to the mid-thigh.
Postoperative analgesia was assessed by by means of a color analogue scale (CAS). Patients with mild or moderate postoperative pain (CAS score > 30 to 45 mm and 46 to 55 mm respectively) received nalbuphine 0.2 mg/kg and 0.3 mg/kg respectively.
Primary outcome measure
Time to first analgesic request of nalbuphine after the surgery by Kaplan- Meier analysis. Postoperative analgesia was assessed by means of a colour analogue scale (CAS). Pain CAS score at rest, was assessed in the recovery room (0), 2, 4, 6, 8, 18, 24 hours postoperatively and the tourniquet pain (0). Total number of rescue nalbuphine doses and the total amount of nalbuphine for the 24 hours observational period.
Secondary outcome measures
1. Classification of motor and sensory block
2. Restlessness based on dichotomous(yes or no)
3. Incidence of nausea and/or vomiting
4. Sedation level using a four-point scale
5. Childrens parents satisfaction score was assessed on the second postoperative day, using a numerical scale.
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Children who underwent Achilles lengthening
2. Children with club foot
Target number of participants
Total final enrolment
Participant exclusion criteria
1. Children with neurologic or neuromuscular disease or problems in communication
2. Childrens parents refusal
3. Skin infection at the site of needle insertion
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
8 V. Mela str
Department of Anesthesiology & the Pharmacy Department of General Children's Hospital (Greece)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
2012 results in https://www.ncbi.nlm.nih.gov/pubmed/22297020 (added 24/01/2020)