External Oblique—Intercostal (EOI) Fascial Plane Block for Upper Abdominal Surgery: A Case Series and Convenience-Study Report with Literature Integration
Importance: Regional truncal blocks that reliably cover the upper abdomen are desirable for opioidsparing
anesthesia and enhanced recovery after surgery (ERAS). The external oblique–intercostal
(EOI) fascial plane block is a recently described technique targeting the anterior and lateral branches
of the thoracoabdominal nerves and may provide useful analgesia for procedures above the umbilicus.
Objective: To present institutional convenience-study outcomes and a clinical case series experience
using the EOI block (often paired with quadratus lumborum [QL] blocks) for outpatient upper abdominal
surgery and to place these results in the context of current published evidence.
Design, Setting, and Participants: Retrospective convenience review of consecutive outpatient upperabdominal
procedures performed at a community hospital over a 3-month period; comparison made
to historic cases receiving QL block only over the prior 6 months. Inclusion/exclusion criteria and
procedural details followed institutional IRB guidance (convenience dataset). Outcome measures
included opioid use (morphine milligram equivalents, MME), postoperative nausea and vomiting
(PONV), and phase-II discharge time.
Main Outcomes and Measures: Total opioid consumption (intraop + PACU, reported as MME),
requirement for opioid in phase II, PONV incidence, and time to discharge.
Results: In the convenience cohort, patients receiving combined bilateral EOI + QL (n = 42) had a
mean total MME of 4.1 (range 0–17.4) compared with QL-only patients (n = 54) mean MME 12.8
(range 0–31.1). Phase-II opioid requirement was 4/42 vs 15/54; PONV in phase II was 2/42 vs 9/54.
Mean time to discharge was 98 minutes (EOI+QL) vs 136 minutes (QL only). These data are descriptive
and uncontrolled.
Conclusions and Relevance: The EOI block—particularly when used as part of a multimodal regimen
and combined with QL in this institutional experience—was associated with lower perioperative opioid
consumption, reduced PONV, and shorter PACU stays compared with historical QL-only practice.
Published literature remains early and comprised largely of cadaveric work, volunteer dermatomal
studies, case reports/series; randomized evidence is lacking. Larger controlled studies are warranted.
