Background: Limited data exist regarding the safety of ultrasound-guided femoral nerve blockade (US-FNB) in patients with hip fractures treated with anti-Xa direct oral anticoagulants (DOAC).

Objectives: To compare the safety outcomes of US-FNB to conventional analgesia in patients with hip fractures treated with anti-Xa DOAC.

Methods: This observational exploratory prospective study included 69 patients who presented to our emergency department (ED) in 3 years with hip fracture and who were treated with apixaban or rivaroxaban. Patients received either a US-FNB (n=19) or conventional analgesics (n=50) based on their preference and, and the presence of a trained ED physician qualified in performing US-FNB. Patients were observed for major bleeding events during and 30 days after hospitalization. The degree of preoperative pain and opioid use were also observed.

Results: We found no significant difference in the number of major bleeding events between groups (47.4% vs. 54.0%, P = 0.84). Degree of pain measured 3 and 12 hours after presentation was found to be lower in the US-FNB group (median visual analog scale of pain improvement from baseline of -5 vs. -3 (P = 0.002) and -5 vs.-4 (P = 0.023), respectively. Opioid administration pre-surgery was found to be more than three times more common in the conventional analgesia group (26.3% vs.80%, P < 0.0001).

Conclusions: Regarding patients treated with Anti-Xa DOAC, US-FNB was not associated with an increase in major bleeding events compared to conventional analgesia, although it was an effective means of pain alleviation. Larger scale randomized controlled trials are required to determine long-term safety and efficacy.