Lessons Learned from the Pediatric Regional Anesthesia Network

By Benjamin Walker, MD
Director of Pediatric Pain Management, American Family Children’s Hospital
Associate Professor of Anesthesiology, Department of Anesthesiology
University of Wisconsin School of Medicine and Public Health
Madison, Wisconsin

The Pediatric Regional Anesthesia Network (PRAN) is a prospective, observational study of complications from regional anesthesia procedures performed at over 20 children’s hospitals. Since its inception in 2007, more than 100,000 blocks have been entered into the database. Early analyses of PRAN data revealed few complications and a zero incidence for some major complications,1,2 indicating a need for a larger sample size to better assess the risk of major complications such as neurological problems, local anesthetic toxicity (LAST), hematoma and serious infection. Recently, the entire database was analyzed for these and other serious incidents.3

Overall, there were very few major complications reported. There were no cases of paralysis, and only one case each of an epidural abscess (in an infant with a lumbar epidural) or hematoma (from paravertebral catheters). There was a low rate of transient sensory deficit (2.4:10,000, 95% CI 1.6-3.6:10,000), with only two cases of deficits lasting beyond three months. The rate of LAST was very low (0.76:10,000, 95% CI 0.3-1.6:10,000), but there was a significantly increased risk in infants younger than six months (OR 7.42, 95% CI 1.31-39.25, p = 0.02).The rate of cutaneous infection was also quite low at approximately 0.5%, with a slightly higher rate reported in neuraxial catheters compared to peripheral catheters, and no infections reported with single-injection blocks.

This most recent analysis of the PRAN data also reaffirmed our earlier results regarding the safety of performing blocks under general anesthesia (GA).2 There was no additional risk for neurologic complications or LAST with blocks performed under GA. In fact, the risk was actually higher with blocks performed awake (OR 2.93, 95% CI 1.34-5.52, p < 0.01), even when adjusted for age to account for the difficulty in diagnosing subtle neurologic deficits in younger children. Although it may be tempting to say that performing blocks under GA is safer than awake, approximately 94% of all blocks were performed under GA, so there was a relatively small comparison group for awake blocks. Therefore, in light of the limitations of the database, a conservative interpretation would be that performing blocks under GA is at least as safe as with the patient awake. In addition, we did not find any neurologic complications associated with interscalene blocks placed under GA, despite doubling the sample size from our previous analysis.4 Interscalene blocks had been singled out as unsafe to perform under GA in the original American Society of Regional Anesthesia guidelines based on adult case reports, but the most recent version has removed this stipulation based in part on results from the PRAN.5

Subgroup analysis with a low event rate is difficult, as further splicing of the data often yields very wide confidence intervals, so these results need to be interpreted with caution. However, our subgroup analyses did not support many accepted truths in pediatric regional anesthesia. For example, we did not find any evidence that thoracic epidurals are “higher risk” than lumbar or caudal based on neurologic problems or dural puncture. We also could not find any evidence that caudal catheters are higher risk for infection. Rather, the duration of the catheter (regardless of location) was the most significant risk factor for infection, as well as an association with ASA class 3 or greater. Finally, we could not find an association between ultrasound or test dose utilization and a reduction in LAST.

The results from the PRAN should be reassuring to those performing these procedures, but there are significant limitations to the data that need to be acknowledged. The PRAN is a prospective, observational trial that relies on self-report from clinicians. Although there is a robust auditing process, there is still a possibility that some complications are not reported. In addition, follow-up processes differ among institutions, and complications occurring after the follow-up period rely on passive reporting from patients, families and surgeons. Many complications are based on clinician judgment, so there will be heterogeneity in reporting. Gathering data on rare complications requires a large sample size and the efforts of multiple institutions, and some degree of data resolution must be sacrificed to do so. However, despite these limitations, we do believe that severe complications, such as paralysis or hematoma, would be captured by the database.

Another major limitation of the PRAN is that it cannot answer questions of efficacy or provide guidance for specific procedures. These questions are better suited to prospective, randomized trials with standardized protocols and a defined control group. The lessons learned from the PRAN and other major audits endorse the safety of performing these procedures in children.3,6,7 We have less evidence in our field for how our regional procedures affect patient outcomes, such as length of stay and functional recovery, so future research endeavors should focus on these topics.

References

  1. Polaner DM, Taenzer AH, Walker BJ, Bosenberg A, Krane EJ, Suresh S, Wolf C, Martin LD: Pediatric Regional Anesthesia Network (PRAN): a multi-institutional study of the use and incidence of complications of pediatric regional anesthesia. Anesth Analg 2012; 115: 1353-64
  2. Taenzer AH, Walker BJ, Bosenberg AT, Martin L, Suresh S, Polaner DM, Wolf C, Krane EJ: 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: 279-283
  3. Walker BJ, Long JB, Sathyamoorthy M, Birstler J, Wolf C, Bosenberg AT, Flack SH, Krane EJ, Sethna NF, Suresh S, Taenzer AH, Polaner DM on behalf of the Pediatric Regional Anesthesia Network. Complications in Pediatric Regional Anesthesia: An Analysis of More than 100,000 Blocks from the Pediatric Regional Anesthesia Network. Anesthesiology 2018; 129:721-32.
  4. Taenzer A, Walker BJ, Bosenberg AT, Krane EJ, Martin LD, Polaner DM, Wolf C, Suresh S: Interscalene Brachial Plexus Blocks Under General Anesthesia in Children: Is This Safe Practice? A Report From the Pediatric Regional Anesthesia Network (PRAN). Reg Anesth Pain Med 2014; 39: 502-505
  5. Neal JM, Barrington MJ, Brull R, Hadzic A, Hebl JR, Horlocker TT, Huntoon MA, Kopp SL, Rathmell JP, Watson JC. The Second ASRA Practice Advisory on Neurologic Complications Associated With Regional Anesthesia and Pain Medicine: Executive Summary 2015. Reg Anesth Pain Med 2015;40:401-30
  6. Ecoffey C, Lacroix F, Giaufré E, Orliaguet G, Courrèges P: Epidemiology and morbidity of regional anesthesia in children: a follow-up one-year prospective survey of the French-Language Society of Paediatric Anaesthesiologists (ADARPEF). Paediatr Anaesth 2010; 20: 1061-9
  7. Llewellyn N, Moriarty A: The national pediatric epidural audit. Paediatr Anaesth 2007; 17: 520-33

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