Continuous psoas compartment blocks after major orthopedic surgery in children: a prospective computed tomographic scan and clinical studies

Abstract

Femoral shaft or hip surgeries are very painful for children. We conducted both computed tomographic (CT) and clinical prospective studies to define new landmarks in children and to evaluate the effectiveness of continuous psoas compartment blocks (CPCBs) using disposable elastomeric pumps. In a preliminary CT scan study of 20 patients, the plexus depth was correlated to patient age and the optimal point of puncture for CPCB was three-quarters of the distance from the spinous process of L4 to a line parallel to the spinal column passing through the posterior superior iliac spine. In a subsequent prospective series, a CPCB was administered before surgery to 15 children for pain relief after femoral and hip osteotomies. After general anesthesia, a 0.5 mL/kg bolus of a mixture of 1% lidocaine with epinephrine (1/200.000) and 0.5% ropivacaine was injected through the CPCB catheter. After contrast media assessment of the catheter location, a disposable pump (Infusor LV); Baxter, Paris, France) with 0.2% ropivacaine was connected and pump flow was adjusted to the patient's weight (0.2 mg x kg(-1) x h(-1)). Postoperative pain was evaluated using a visual analog scale or the Children and Infants Postoperative Pain Score at hour H1, H6, H12, H18, H24, H36, and H48, and in terms of rescue analgesia, adverse events, and motor blocks. All blocks were effective during surgery. Postoperative analgesia was excellent. The median pain scores were 1 for H1 and 0 beginning H6. The motor blockade was minimal before 24 h and absent thereafter. No major adverse event was noted. Parents of 93% of the children were satisfied. We conclude that postoperative analgesia with CPCB is a very effective technique in children after major proximal lower limb orthopedic surgery. The CT scan landmarks described in this study were more medial than the conventional landmarks used in the literature.

Implications: Continuous psoas compartment blocks provide optimal pain relief in children after major orthopedic surgery without major adverse events. The landmarks used, defined in a preliminary computed tomographic scan study, were more medial than conventional landmarks.