Disclaimer: This article is intended solely for informational and educational purposes only. It does not constitute medical advice.
Peripheral intravenous (IV) access is performed more than one billion times worldwide each year and is essential for perioperative, critical, and emergency care settings (Beecham, Agarwal, & Tackling, 2025). Site selection is central to successful cannulation, patient comfort, and preservation of vascular integrity, and anesthesia providers must be familiar with anatomy, patient-specific factors, and adjunct technologies that influence the choice of an optimal site for peripheral IV access.
In the upper extremity, the nondominant arm is generally preferred due to lower rates of dislodgement and thrombophlebitis and greater patient comfort (Beecham et al., 2025). The metacarpal veins on the dorsum of the hand are the most frequently attempted as a first site because of their visibility and accessibility, despite being more painful due to a dense concentration of cutaneous nerve endings (NYSORA, 2024).
These veins drain proximally into the cephalic and basilic veins of the forearm, which converge near the antecubital fossa via the median cubital and median antebrachial veins. The cephalic vein is large and easily palpated but can be difficult to access in patients with significant subcutaneous adiposity or muscle bulk, while the median antebrachial vein is well suited to short-term access provided the operator avoids its bifurcation points, since venous valves clustered near branch points increase the likelihood of failed cannulation (Beecham et al., 2025; NYSORA, 2024). The median cubital vein, though large and easily accessed, is frequently reserved for phlebotomy and can be more difficult to cannulate in patients with obesity.
Vessel selection criteria converge on straight, unbranched, distal veins that are visible or palpable and free of induration, sclerosis, or bruising suggestive of thrombosis (Beecham et al., 2025; NYSORA, 2024). Tourniquet application 5 to 10 cm proximal to the intended site, gravity-dependent limb positioning, and local application of warmth are established adjuncts to venous engorgement that facilitate site selection, particularly in patients with cold extremities or anatomically difficult veins.
Patient-specific factors substantially influence the difficulty of peripheral IV access and the likelihood of a site being successful. Obesity is a well-documented risk factor for difficult peripheral access; a prospective study of children undergoing noncardiac surgery found that obese children were significantly more likely to fail first-attempt cannulation and to require multiple attempts compared with lean controls, an outcome largely attributable to reduced vein visibility and palpability beneath a thicker subcutaneous adipose layer (Nafiu et al., 2010).
Notably, that study found that when the dorsum of the hand failed in obese children, the volar surface of the wrist offered a significantly higher secondary success rate than in lean children, a finding the authors attributed to relative sparing of adipose deposition over the flexor tendons and retinaculum at that site (Nafiu et al., 2010).
When landmark-based techniques fail or difficult access is anticipated, ultrasound guidance offers a validated alternative. A systematic review and meta-analysis of seven randomized controlled trials found that ultrasound-guided cannulation significantly increased the odds of successful peripheral access compared with standard technique (pooled odds ratio 2.42), although it conferred no significant advantage in procedure time or number of skin punctures (Egan, Healy, O’Neill, Clarke-Moloney, Grace, & Walsh, 2013).
The authors recommended reserving ultrasound guidance for patients with confirmed difficult access rather than as a first-line approach for routine cannulation, given the additional equipment, training, and time requirements involved.
Selecting a peripheral IV access site for surgical and anesthetic care requires integration of anatomic knowledge, patient-specific risk factors such as obesity, and judicious use of adjuncts including tourniquet technique, limb warming, and ultrasound guidance when standard approaches fail.
References
Beecham, G. B., Agarwal, A., & Tackling, G. (2025). Peripheral line placement. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK539795/
Egan, G., Healy, D., O’Neill, H., Clarke-Moloney, M., Grace, P. A., & Walsh, S. R. (2013). Ultrasound guidance for difficult peripheral venous access: Systematic review and meta-analysis. Emergency Medicine Journal, 30(7), 521–526. https://doi.org/10.1136/emermed-2012-201652
Nafiu, O. O., Burke, C., Cowan, A., Tutuo, N., Maclean, S., & Tremper, K. K. (2010). Comparing peripheral venous access between obese and normal weight children. Pediatric Anesthesia, 20(2), 172–176. https://doi.org/10.1111/j.1460-9592.2009.03198.x
NYSORA. (2024, September 3). Finding the perfect vein: Tips for selecting the ideal site for IV cannulation. https://nysora.com/education-news/tips-for-selecting-the-ideal-site-for-iv-cannulation/
