SLR - July 2010 - Michael R Brewer

Continuous peripheral nerve blocks for postoperative analgesia in children: feasibility and side effects in a cohort study of 339 catheters

Reference
Dadure C,  Bringuier S, Raux O, Rochette A, Troncin R, Canaud N, Lubrano-Lavadera J, Capdevila X. Can J Anesth. 2009;56:843-50

Scientific Literature Reviews

Reviewed by:  Michael R Brewer, DPM
Residency Program: Maricopa Medical Center PM&S 36, Phoenix AZ

Podiatric Relevance:
Post-operative pain management continues to be a challenging area of foot and ankle surgical practice. The complications associated with opioid analgesia include nausea, pruritis, constipation, and perhaps the most worrisome, addiction. Any method or technology that allows for decreased dosing or the elimination of the use of mu-receptor agonists should be explored thoroughly by the podiatric surgeon. Continuous peripheral nerve blocks (CPNB’s) are hypothesized to be just such a technology.

Methods:
The authors performed a cohort study of 339 catheters placed in 292 children from 2002-2006 in Montpellier University Hospital in France.  Using sterile technique and a nerve stimulator, CPNBs were positioned after the initiation of general anesthesia or conscious sedation. Each child received a bolus of anesthetic between 0.5-1 ml/kg with a subsequent infusion rate between 0.1-0.2 ml/hr. Post-operative pain adjuncts were utilized and consisted of non-steroidal anti-inflammatory drugs dosed 2-4 times daily. Pain scores for children <7 years old were evaluated by the CHIPPS pain score and older children were evaluated with the VAS. All adverse events were recorded including mechanical dysfunction, hematoma, insensate extremity, pruritis, nausea, vomiting, urinary retention, signs of local anesthetic toxicity, local infection, pus, cellulitis, fever and/or shivering.. 

Results: 
Ninety percent of the catheters were placed in the lower limb. Foot surgery with continuous popliteal nerve block was the most common location (50.5%). The median duration of CPNB was 61.6 hours. Bupivicaine dosed at 0.61-1.22 mg/kg was initially the most common dose, but subsequently ropivicaine 0.2% 0.49 to 0.98 mg/kg was utilized as it allowed for pain control without paralysis. 93% received adjunctive Tylenol, 89% received NSAIDS,  22% received tramadol, and 3% received morphine. The median pain score was 0 throughout the study period. 88% of children or parents were very satisfied, 11% satisfied, and 1% unsatisfied.  The most common complication was mechanical problems (20.1%) and was characterized by catheter dislodgement from child movement. Nausea and vomiting occurred in 14.7%, was associated with general anesthesia. Notably low rates of urinary retention (1.5%) and pruritis (0.9%) were observed.

Conclusions:
Continuous peripheral nerve blocks appear to be effective at virtually negating the need for opiates in the post-operative period. This reduces potential adverse side effects of narcotics. The treatment appears to be safe in children and has been shown in other studies to be effective in adults. Local anesthetics should be favored over mu receptor agonists in light of decreased side effects as well as risk reduction for substance dependence.  The more experience we gain with dosing regiments and treatment protocols, the more effectively we can carry out this directive.

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