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Residual Neurological Symptoms After Peripheral Nerve Blocks for Pediatric Knee Surgery
Robert J Tamai1, Brian T Sullivan, Rushyuan J Lee
1Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD.
Insights
Peripheral nerve blocks (PNBs) can cause neurological symptoms in children undergoing knee surgery. Obesity and female sex are risk factors for these symptoms, which may persist long-term.
Area of Science:
- Anesthesiology
- Pediatric Orthopaedic Surgery
- Neurology
Background:
- Peripheral nerve blocks (PNBs) are effective for pain management in pediatric orthopaedic surgery.
- Neurological complications from PNBs are rare but documented in adults.
- This study examines PNB complications in pediatric knee surgery.
Purpose of the Study:
- To investigate the incidence and characteristics of neurological complications associated with PNBs in children undergoing knee surgery.
- To identify risk factors for PNB-associated neurological symptoms in this population.
Main Methods:
- Retrospective review of 121 children undergoing knee surgery (October 2014 - September 2016).
- Analysis of 100 patients who received PNBs, focusing on postoperative neurological symptoms.
- Statistical analysis (Student t tests, Fisher exact tests) to identify associations with patient characteristics, surgical details, and PNB parameters.
Main Results:
- 6% of patients (6/100) experienced PNB-associated neurological symptoms, primarily paresthesias, in a pattern consistent with the nerve block.
- Symptoms were linked to femoral nerve blocks and were more common in patients with higher BMI (obesity) and female sex.
- Three cases of persistent symptoms were noted at long-term follow-up; no procedural complications were reported.
Conclusions:
- Pediatric knee surgery with PNBs is associated with a higher rate of neurological symptoms than previously reported.
- Obesity and female sex are significant risk factors for developing PNB-associated neurological symptoms.
- These symptoms can be persistent, underscoring the need for careful patient selection and monitoring.
Background:
Peripheral nerve blocks (PNBs) provide excellent pain control and reduce the need for systemic analgesics in orthopaedic surgery. PNBs rarely cause complications; however, a few studies of adults have reported neurological complications during the early postoperative period. We investigated complications associated with the use of PNBs during pediatric knee surgery.
Methods:
We reviewed the medical records of all 121 children (aged ≤18 y) who underwent knee surgery by 1 orthopaedic surgeon between October 2014 and September 2016. One hundred of these patients had PNBs. The primary outcome of interest was postoperative neurological symptoms. Other study parameters were patient characteristics, surgical details, tourniquet use/duration of use, PNB guidance method and anatomic location, and PNB-associated procedural complications (eg, blood loss, anesthetic neurotoxicity). Data were analyzed using Student t tests and Fisher exact tests, with significance at P<0.05.
Results:
Of the 100 patients with PNBs, 23 had persistent lower-extremity paresthesias postoperatively. Most paresthesias were attributed to the surgical procedure; however, at first follow-up (mean, 1.6±0.4 wk) 6 patients had paresthesias and other neurological symptoms proximal to the knee in a distribution pattern consistent with the PNB. Three of these were unresolved at last follow-up (mean, 56±37 wk). All neurological symptoms were associated with femoral nerve blocks. The 6 patients with suspected PNB-associated neurological symptoms had a significantly higher mean BMI (31±5.5) than the 94 patients without symptoms (23±6.1; P=0.002). Obesity was associated with PNB-associated neurological symptoms (P=0.002), as was female sex (P<0.001). No significant differences were found in terms of age, surgery duration, or tourniquet use/duration of use. Most PNB procedures used ultrasound guidance, and no procedural complications were reported.
Conclusions:
Compared with previous studies, we report a higher rate (6%) of PNB-associated neurological symptoms in children after knee surgery with PNBs. Obesity and female sex were associated with persistent neurological symptoms in the distribution pattern of the PNB.
Level Of Evidence:
Level III (retrospective comparative study).
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