Author: Eric S. Schwenk, et al.
Regional Anesthesia and Pain Medicine, BMJ Journals.
Rib fractures in older adults are associated with substantial pain, impaired ventilation, pneumonia, delirium, and increased mortality. This pilot randomized study compared an erector spinae plane catheter, an intravenous lidocaine infusion, and standard multimodal analgesia in patients with multiple unilateral rib fractures.
Study Design
The investigators enrolled patients 55 years or older with at least three unilateral rib fractures. Participants were randomly assigned to one of three groups:
- Continuous erector spinae plane catheter
- Intravenous lidocaine infusion
- Multimodal analgesia alone
Pain scores, opioid consumption, pulmonary function, delirium, sedation, adverse effects, and vital capacity were assessed for 72 hours.
The study was primarily designed to evaluate feasibility and help determine the most appropriate outcomes for a larger definitive trial.
Key Findings
Twenty-four patients were included in the analysis.
Average pain scores did not differ significantly among the erector spinae plane, lidocaine, and control groups during the first three days.
Opioid consumption was also similar among the groups:
- Erector spinae plane catheter: median 25.0 mg
- Lidocaine infusion: median 26.7 mg
- Multimodal analgesia: median 20.0 mg
The overall difference in opioid use was not statistically significant.
Although the study did not demonstrate a clear analgesic advantage, the small sample size means that a modest early benefit from the erector spinae plane block or lidocaine infusion cannot be excluded.
Pulmonary Complications and Delirium
Pneumonia occurred more frequently in patients receiving multimodal analgesia alone. The investigators suggested that pulmonary complications may be a more clinically meaningful primary outcome than pain scores in a future definitive trial.
Delirium occurred less frequently among patients receiving erector spinae plane catheters. This finding is potentially important because delirium is common and clinically consequential in older trauma patients, although the pilot study was too small to establish a definitive protective effect.
Lidocaine Safety Concerns
Three patients receiving intravenous lidocaine developed symptoms considered potentially consistent with local anesthetic systemic toxicity.
These events occurred despite the use of a conservative dosing protocol. The findings raise concern about systemic lidocaine infusions in older trauma patients, who may have altered drug clearance, reduced physiologic reserve, or unrecognized comorbidities.
Future trials involving intravenous lidocaine should include systematic monitoring for neurologic and cardiovascular symptoms of local anesthetic systemic toxicity.
Feasibility of a Larger Trial
Recruitment averaged approximately 2.4 patients per month, and two patients withdrew.
The investigators estimated that a definitive trial using pneumonia as a primary outcome would require enrollment of approximately 11 patients per month over three years. This would likely require a multicenter design.
Two patients died before the 30-day assessment, emphasizing the seriousness of multiple rib fractures in older adults.
Clinical Implications
This pilot study did not establish that erector spinae plane catheters or intravenous lidocaine provide better pain relief or reduce opioid consumption compared with multimodal analgesia alone.
However, the study suggests that pain scores and opioid use may not capture the most meaningful potential benefits of regional analgesia in patients with rib fractures.
Future research should focus on outcomes such as:
- Pneumonia
- Respiratory failure
- Delirium
- Intensive care admission
- Mechanical ventilation
- Hospital length of stay
- Mortality
The possible reduction in delirium with erector spinae plane catheters deserves further investigation. In contrast, the possible toxicity observed with lidocaine infusions warrants caution.
Conclusion
Pain scores and opioid consumption were comparable among erector spinae plane catheters, intravenous lidocaine infusions, and multimodal analgesia alone.
The study did not rule out a modest benefit from either intervention, but pulmonary complications and delirium may be more appropriate outcomes for a larger trial.
Possible local anesthetic systemic toxicity occurred in three patients receiving lidocaine despite conservative dosing, highlighting the need for careful patient selection and monitoring, particularly among older adults.
We thank Regional Anesthesia and Pain Medicine and BMJ Journals for allowing us to summarize this important clinical research.