Cadaveric findings of the effect of rib fractures on spread of serratus plane injections

摘要

Serratus plane (SP) blocks provide effective analgesia for patients with rib fractures following chest trauma and are an attractive alternative if thoracic epidural analgesia is contra-indicated.1 Serratus plane blocks involve injecting local anesthetic superficial to the serratus anterior muscle (SAM) in the mid-axillary line using ultrasound guidance. A cadaveric study showed spread of SP injectate to be limited to the lateral cutaneous branches of intercostal nerves with no direct spread between fascial layers deep enough to reach the intercostal nerves. Rib periosteum and intercostal muscles are, however, innervated by the intercostal nerves, which travel between internal and innermost intercostal muscles. Thus, effective analgesia for rib fractures logically requires local anesthetic to spread across multiple tissue planes to affect this deeper layer. We wanted to show "If the presence of rib fractures facilitated spread of SP injectate towards deeper structures?"