Bolton, Patrick B.

Background: The modern scalp block consists of local anesthesia injections that target the supraorbital, supratrochlear, zygomaticotemporal, auriculotemporal, and greater and lesser occipital nerves. Limited data exist on the local anesthetic spread that occurs with this technique. This study examines the extent of the spread of a scalp block using methylene blue in a cadaveric model. Methods: A traditional landmark-based scalp block was performed on 6 unembalmed human cadavers using 25-G, 1.5-inch needles to inject 1 to 2 mL of methylene blue 0.1% at each nerve bilaterally; a total volume of 20 mL was injected. The cadavers were then dissected, and the spread of injectate was measured and recorded. Results: All the nerves required for analgesic coverage were appropriately stained by the injections, except for in 2 specimens where the lesser occipital nerve could not be identified. The zygomatic (stained in 2 of 8 specimens) and temporal (stained in 5 of 8 specimens) branches of the facial nerve were stained as a result of the zygomaticotemporal and/or auriculotemporal injections. Tracking from the zygomatic injection site was noted as far inferior as the temporalis muscle attachments on the mandible. Conclusions: This cadaveric study confirms that the landmark-based technique for scalp blocks consistently stained all 6 nerves involved in scalp innervation. There was significant unintentional spread to the branches of the facial nerve when using the landmark technique.

Objectives: Topical vasoconstrictors and intravenous tranexamic acid (IV TXA) are safe and efficacious to decrease bleeding and improve the surgical field during endoscopic sinus surgery (ESS). The purpose of this study was to investigate practice patterns, awareness of clinical evidence, and comfort levels among anesthesia providers regarding these hemostatic agents for ESS. Methods: A total of 767 attending anesthesiologists, residents, and certified registered nurse anesthetists (CRNAs) at 5 United States academic centers were invited to participate in a survey regarding their experience with IV TXA and 3 topical vasoconstrictor medications (oxymetazoline, epinephrine, and cocaine) during ESS. Results: 330 (47%) anesthesia providers responded to the electronic survey. 113 (97%) residents, 92 (83%) CRNAs, and 52 (68%) attendings managed 5 or fewer ESS cases per month. Two-thirds of providers had not reviewed efficacy or safety literature for these hemostatic agents. Oxymetazoline was perceived safest, followed by epinephrine, IV TXA, and cocaine. Respondents considered potential side effects over surgical field visibility when selecting agents. The majority of providers had no formal training on these agents for ESS, but indicated interest in educational opportunities. Conclusion: Many anesthesia providers are unfamiliar with safety and efficacy literature regarding agents used to improve hemostasis for ESS, highlighting a need for development of relevant educational resources. Rhinologic surgeons have an opportunity to communicate with anesthesia colleagues on the use of hemostatic agents to improve the surgical field during ESS.