Use of Liposomal Bupivacaine in Pediatric Peripheral Nerve Blocks after Traumatic Amputation.

Liposomal bupivacaine has been explored for indications in regional anesthesia, but little has been reported about its use in pediatric patients. In March 2021, the FDA approved an indication for liposomal bupivacaine as an infiltrated local anesthetic in children older than the age of six. Despite this recently expanded indication, the literature lacks reports of use for peripheral nerve blockade in children. We describe a case where liposomal bupivacaine was used for femoral and sciatic nerve blocks in a 5-year-old child with traumatic amputation of his lower leg. Pain control was excellent, with no pain or opioid use reported during the first 62 hours. After the regional anesthesia subsided, the patient required in total 4 oral doses of oxycodone 0.1 mg/kg prior to discharge. The patient did not develop chronic pain or phantom limb syndrome. While liposomal bupivacaine is not currently FDA-approved for peripheral nerve blockade in children, this case highlights a potentially effective use of this drug and possible area for further investigation.

A Novel Use of Liposomal Bupivacaine in Erector Spinae Plane Block for Pediatric Congenital Cardiac Surgery.

We describe the use of liposomal bupivacaine (Exparel) in erector spinae plane blocks for two patients undergoing pediatric cardiac surgery with cardiopulmonary bypass and one undergoing division of the compressive vascular ring. The perioperative course of all patients was remarkable for low pain and sedation scores, especially after chest tube removal. Erector spinae plane blocks are an expanding pain-control technique in both adult and pediatric cardiac surgery for postoperative analgesia. Liposomal bupivacaine offers prolonged analgesia and may be an attractive option for this indication.

Removal of a knotted catheter lodged in an appendicostomy tract.

Knots are an unusual complication of catheterization procedures but have been reported in a variety of circumstances. Refractory constipation and colonic dysmotility disorders can be treated with a surgically created appendicostomy that is typically catheterized nightly to administer an antegrade colonic enema. We report a case of a catheter that formed a knot and became lodged in an appendicostomy. We describe the method used to remove the knot and make a recommendation to prevent this complication.

Mechanical properties of the gastrocnemius aponeurosis in wild turkeys.

In many muscles, the tendinous structures include both an extramuscular free tendon as well as a sheet-like aponeurosis. In both free tendons and aponeuroses the collagen fascicles are oriented primarily longitudinally, along the muscle's line of action. It is generally assumed that this axis represents the direction of loading for these structures. This assumption is well founded for free tendons, but aponeuroses undergo a more complex loading regime. Unlike free tendons, aponeuroses surround a substantial portion of the muscle belly and are therefore loaded both parallel (longitudinal) and perpendicular (transverse) to a muscle's line of action when contracting muscles bulge to maintain a constant volume. Given this biaxial loading pattern, it is critical to understand the mechanical properties of aponeuroses in both the longitudinal and transverse directions. In this study, we use uniaxial testing of isolated tissue samples from the aponeurosis of the lateral gastrocnemius of wild turkeys to determine mechanical properties of samples loaded longitudinally (along the muscle's line of action) and transversely (orthogonal to the line of action). We find that the aponeurosis has a significantly higher Young's modulus in the longitudinal than in the transverse direction. Our results also show that aponeuroses can behave as efficient springs in both the longitudinal and transverse directions, losing little energy to hysteresis. We also test the failure properties of aponeuroses to quantify the likely safety factor with which these structures operate during muscular force production. These results provide an essential foundation for understanding the mechanical function of aponeuroses as biaxially loaded biological springs.