Point‐of‐Care Ultrasound to Identify Landmarks of the Proximal Humerus

Abstract

Objectives The inability to identify landmarks is an absolute contraindication for intraosseous access. The feasibility of landmark identification using ultrasound (US) has been demonstrated on human cadavers. We aimed to study the feasibility of point‐of‐care US in identifying proximal humerus landmarks in living human patients. Methods This was a prospective cohort study conducted from May 3 to June 7, 2017, after approval from the Institutional Review Board at the Cleveland Clinic. Sixty upper extremities of 30 consenting participants across 3 distinct body mass index (BMI) groups (normal, obese, and morbidly obese) were alternately examined with a 12 L‐RS linear US transducer (GE Healthcare, Chicago, IL) by 2 investigators. Six anatomic landmarks were identified: the humeral shaft, the surgical neck of the humerus, the lesser tubercle, the greater tubercle, the inter tubercular sulcus, and the target site for needle insertion on the greater tubercle. Rates of successful identification of all 6 landmarks as defined by independent agreement between the investigators were reported as estimated incidence rates with 95% bootstrap confidence interval (CI) sampling at the participant level. Results Ultrasound had an overall success rate of 0.87 (95% CI, 0.78–0.95) in identifying all 6 landmarks with slight variability among various BMI groups. After excluding the surgical neck, the overall success rate improved to 0.93 (95% CI, 0.87–0.98), with minimum variability across BMI groups and no change in the ability to identify the target site. Conclusions Ultrasound is reliable in identifying proximal humerus intraosseous landmarks, with reasonable accuracy across various BMI groups.