Prolongation of spinal duration by escalating doses of intrathecal epinephrine in lower limb arthroplasty

Abstract

Aim: The optimal dose of low-dose intrathecal epinephrine in the absence of intrathecal opioids is unknown. Materials & methods: Prospective, randomized, double blind clinical trial of patients undergoing lower limb arthroplasties. The primary end point was spinal block duration measured via motor and sensory block duration. Results: 30 patients undergoing lower limb arthroplasty were randomized into one of six groups with varying intrathecal epinephrine doses 0–100 mcg. There was a direct linear effect between motor block duration and intrathecal epinephrine dose with higher doses being associated with longer block duration (p = 0.011). Mean motor block duration was 3.74 ± 1.13, 3.36 ± 0.47, 3.39 ± 0.60, 4.06 ± 0.98 and 5.20 ± 1.41 h for the EPI0, EPI25, EPI50, EPI75 and EPI100 groups respectively. Conclusion: This study reveals that low-dose intrathecal epinephrine (75–100 mcg) in the absence of intrathecal opioids can be reliably used to prolong motor block duration in lower limb arthroplasty.

Clinical Trial Registration: NCT02619409 (ClinicalTrials.gov)

Plain language summary

What is this summary about?

Here, we summarize the results of the addition of a medicine called epinephrine to a type of anesthesia called spinal anesthesia which involves injection of medication into the fluid surrounding the spinal cord. The study was to determine the optimal amount of epinephrine needed to prolong the effect of spinal anesthesia for patients undergoing replacements of their hips and/or knees.

What were the results?

The study showed that the addition of low-dose epinephrine to spinal anesthesia prolongs the motor block – or inability to move the leg – in a linear fashion with higher doses of epinephrine associated with longer motor block. Our results did not show a significant difference in sensory block, or the inability to feel the leg.

What do the results mean?

The study shows that the addition of low-dose epinephrine to spinal anesthesia can reliably prolong the effect of the anesthesia which may be needed in more complicated hip or knee surgeries.

Tweetable abstract

A prospective, randomized clinical trial investigating escalating doses of low dose intrathecal epinephrine in lower limb arthroplasty found that 75–100 mcg of intrathecal epinephrine can reliably prolong spinal motor block duration.

Keywords::

• anesthesia adjuvants
• epinephrine
• intrathecal injections
• spinal anesthesia
• total hip arthroplasty
• total knee arthroplasty

Supplementary data

Author contributions

C Wolla: analysis and interpretation of data, drafting and revising of the manuscript, and final approval of the version to be published. T Epperson: conception/design of the work, acquisition/analysis/interpretation of the data, drafting/revising of manuscript and final approval of manuscript. E Woltz: acquisition/analysis/interpretation of the data, drafting/revising of manuscript, and final approval of manuscript. B Wolf: acquisition/analysis/interpretation of the data, drafting/revising of manuscript. E Bolin: conception/design of the work, acquisition/analysis/interpretation of the data, drafting/revising of manuscript and final approval of manuscript.

Financial disclosure

The authors have no financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Competing interests disclosure

The authors have no competing interests or relevant affiliations with any organization or entity with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, stock ownership or options and expert testimony.

Writing disclosure

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Data sharing statement

The authors certify that this manuscript reports original clinical trial data. Deidentified, individual data that underlie the results reported in this article (text, tables, figures and appendices), along with the study protocol will be available indefinitely to investigators whose proposed use of the data has been approved by an independent review committee.