Original review article
Alrayashi W, Cravero J, Brusseau R. Unique Issues Related to Regional Anesthesia in Pediatric Orthopedics. Anesthesiol Clin. 2022 Sep;40(3):481-489. PMID: 36049876
Today’s PAAD is a review article on controversial issues in the use of regional anesthesia in pediatric orthopedic surgery. Four areas are highlighted: awake vs asleep blocks, acute compartment syndrome, regional anesthesia and implanted spinal hardware, and ambulatory catheters.
Awake vs asleep blocks is a settled issue in pediatrics. This was demonstrated back in 2014 in a cohort of 54,000 patients and reconfirmed in 2018 in an additional 50,000 patients.[1, 2] “Regional blocks can and should preferably be performed under anesthesia or deep sedation in children of all ages”[3]. Case closed. However, it must be stated that while this statement is strongly supported by the data for general anesthesia, “deep sedation” is not a clearly defined state- it is continuum, perhaps synonymous with general anesthesia or perhaps not, and the term is never used in any of the PRAN reports. Indeed, PRAN data showed that the highest risk of adverse events occurred in sedated patients, and “sedated” is never categorized as light, moderate or deep.
Surgical acute compartment syndrome is the result of an increased pressure in a closed, largely inelastic fascial compartment, usually due to postinjury edema and increased venous capillary pressure. Tissue ischemia is produced by inadequate perfusion resulting in cellular injury. The main symptom is pain, and delay in diagnosis and treatment can be catastrophic, resulting in loss of limb and generalized sepsis. “Pulselessness is definitively not a clinical sign of compartment syndrome. It should be emphasized that peripheral pulses can still be detected in compartments with critically high pressures”.[4] Will a regional block mask and delay diagnosis? In the United States many orthopedic surgeons and anesthesiologists believe it will[4], but in Europe they believe it doesn’t (particularly if lower concentrations of local anesthetics are used).[5, 6] There are anecdotal reports that regional analgesia can in the early detection of compartment syndrome- that is, breakthrough pain in a previously comfortable patient with a block is a strong sign that something is amiss and demands immediate investigation. It is most likely that it is not the block that masks the diagnosis, but rather missing or ignoring the early signs that herald the onset of the event. Almost 70% of acute compartment syndrome cases occur following fractures, mostly involving the tibia and occasionally the elbow, and special caution is mandated for these injuries.
Regional anesthesia and implanted spinal hardware
Intrathecal baclofen pumps are common in children with disabilities, particularly those with spastic cerebral palsy. Does the presence of an intrathecal pump preclude the use of regional anesthesia? Although epidurals are possible with neurosurgical and fluoroscopic guidance, ultrasound guided lumbar plexus blocks probably are safer and may make more sense.[7] The same may be so for patients who have undergone spinal instrumentation and fusion for scoliosis, which make access to the epidural space difficult or impossible.
Ambulatory catheters
Ambulatory peripheral nerve catheters are increasingly being used in pediatrics, not only for their superior pain relief but as an alternative to opioids.[8] There are primarily 2 types of pumps: elastomeric and electronic. Both have pros and cons. Although limited in the volume that can be stored and lacking in bells and whistles like alarms and displays that show the amount of volume remaining, our experience is that the elastomeric pumps are most commonly used and can last for up to 3 days with a very low rate of malfunction. The PRAN database reported no cases of major complications like local anesthetic toxicity or permanent neurologic injury, however the investigators did not stratify the blocks as inpatient or ambulatory. The most common issues included pericatheter leakage, dislodgement, and failed blockade. These adverse events highlight the necessity of bombproof fixation techniques to ensure block success.
References
1. Taenzer, A.H., et al., Asleep versus awake: does it matter?: Pediatric regional block complications by patient state: a report from the Pediatric Regional Anesthesia Network. Reg Anesth Pain Med, 2014. 39(4): p. 279-83.
2. Walker, B.J., et al., Complications in Pediatric Regional Anesthesia: An Analysis of More than 100,000 Blocks from the Pediatric Regional Anesthesia Network. Anesthesiology, 2018. 129(4): p. 721-732.
3. Alrayashi, W., J. Cravero, and R. Brusseau, Unique Issues Related to Regional Anesthesia in Pediatric Orthopedics. Anesthesiol Clin, 2022. 40(3): p. 481-489.
4. Marhofer, P., et al., Regional Anesthesia and Compartment Syndrome. Anesth Analg, 2021. 133(5): p. 1348-1352.
5. Nathanson, M.H., et al., Regional analgesia for lower leg trauma and the risk of acute compartment syndrome: Guideline from the Association of Anaesthetists. Anaesthesia, 2021. 76(11): p. 1518-1525.
6. Lönnqvist, P.A., et al., The European society of regional anesthesia and pain therapy and the American society of regional anesthesia and pain medicine joint committee practice advisory on controversial topics in pediatric regional anesthesia I and II: what do they tell us? Curr Opin Anaesthesiol, 2017. 30(5): p. 613-620.
7. Boretsky, K., et al., Ultrasound-guided lumbar plexus block in children and adolescents using a transverse lumbar paravertebral sonogram: Initial experience. Paediatr Anaesth, 2018. 28(3): p. 291-295.
8. Gurnaney, H., et al., Ambulatory continuous peripheral nerve blocks in children and adolescents: a longitudinal 8-year single center study. Anesth Analg, 2014. 118(3): p. 621-7.