Letters to the Editor: Letter to the Editor
To the Editor
Intraosseous (IO) access has been widely used as a conduit to gain entrance to the vascular space when the intravenous route is not available or difficult to obtain.1 The traditional site for IO access has been the proximal anterior tibia because of ease in identification of landmarks and accessibility. The proximal humerus (PH) has recently been seen as an alternative to the tibia because of decreased pain with initial bolus, decreased medullary pressure resulting in more rapid fluid delivery, and closer proximity to the heart.2
Proximal humerus intraosseous (PHIO) access relies on identification of the greater tubercle through palpation of the surgical neck of the humerus. This method can be especially difficult with patients with prominent deltoid musculature or adipose tissue overlying these landmarks. Success rates for PHIO needle insertion have been cited as low as 76% in 1 study compared with 92% for proximal tibial insertion.3 Moreover, a failed IO needle insertion precludes the immediate use of the same site for another trial.
The PHIO needle insertion site is in the greater tubercle with care to go lateral to the intertubercular sulcus. In the sulcus lies the biceps brachii tendon and branches off the axillary artery. With the standard blind approach, care is taken to avoid these structures by internally rotating the arm to expose more of the greater tubercle, but incorrect placement can still occur. Changes in the trajectory of the needle because of incorrect site identification or inability to mentally visualize the angle of entry can potentially lead to intracapsular or subcutaneous needle placement. With the limitations of the blind approach, an alternative method for identification and placement could prove more effective.
The application of ultrasound to identify the structures of the PH for PHIO access has not yet been described in the literature. Visualizing these specific landmarks has the potential to improve the success rate of what is now considered to be a blind procedure. By using a 13- to 6-MHz ultrasound linear probe (SonoSite Inc, Bothell, WA), this assessment was performed on 5 fresh cadavers with body mass indexes ranging from 20 to 35 kg/m2. We found that, in addition to the greater tubercle, the lesser tubercle, the intertubercular sulcus, and the surgical neck were easily interrogated and identified (Figure 1). Moreover, all 4 anatomical landmarks were very shallow from the skin (within 3 cm) in all cadavers regardless of their various body mass indexes.
Once the target site is identified, standard technique for blind insertion can be used with either manual or automated devices. Although the needle can be difficult to visualize below the periosteum, color flow doppler has been described in the literature to confirm the placement of tibial IO cannulas,4 and it can also be used in the PH (Figure 2).
As the clinical applications and scope of practice for ultrasonography continue to expand,5,6 further studies are needed to evaluate the clinical benefits of this procedure compared with the standard blind approach and in those with difficult palpable anatomy. Improving landmark identification of the PH target site with ultrasound could potentially improve the accuracy of IO needle placement in the emergency or urgent setting.
Sergio Bustamante, MDShravan Cheruku, MDDepartment of Cardiothoracic AnesthesiologyThe Cleveland Clinic FoundationCleveland, Ohiocheruks2@ccf.org
1. Petitpas F, Guenezan J, Vendeuvre T, Scepi M, Oriot D, Mimoz O. Use of intra-osseous access in adults: a systematic review. Crit Care. 2016;20:102.
2. Philbeck TE, Miller LJ, Montez D, Puga T. Hurts so good. Easing IO pain and pressure. JEMS. 2010;35:5862, 6566, 68.
3. Kovar J, Gillum L. Alternate route: the humerus bone—a viable option for IO access. JEMS. 2010;35:5259.
4. Tsung JW, Blaivas M, Stone MB. Feasibility of point-of-care colour Doppler ultrasound confirmation of intraosseous needle placement during resuscitation. Resuscitation. 2009;80:665668.
5. Mahmood F, Matyal R, Skubas N, et al. Perioperative ultrasound training in anesthesiology: A call to action. Anesth Analg. 2016;122:17941804.
6. Sites BD, Chan VW, Neal JM, et al.; American Society of Regional Anesthesia and Pain Medicine; European Society Of Regional Anaesthesia and Pain Therapy Joint Committee. The American Society of Regional Anesthesia and Pain Medicine and the European Society of Regional Anaesthesia and Pain Therapy joint committee recommendations for education and training in ultrasound-guided regional anesthesia. Reg Anesth Pain Med. 2009;34:4046.