Vascular access remains one of the most fundamental components of perioperative and critical care anesthesia. While intravenous (IV) lines are the cornerstone of modern anesthetic practice, intra-arterial (IA) lines offer a level of precision and continuous monitoring that is indispensable in high-acuity situations.
IV lines are the default for fluid resuscitation, medication administration, and anesthetic induction. Peripheral IVs, often placed in the forearm or hand, are relatively easy to insert, safe, and sufficient for most procedures. Compared to arteries, veins are often closer to the skin, easier to penetrate with a needle, and confer a lower risk of hemorrhage due to lower intraluminal pressure (Tucker et al 2025).
A central venous line (CVL) is a special kind of IV that is placed in one of the centrally located, larger veins in the body. These large bore catheters permit larger volumes of fluid to be administered and confer faster systemic distribution as the fluid is introduced closer to the heart. CVLs are also far less likely to clot or fall out of place during repositioning (Ratchagame et al 2021). They are typically reserved for complex cases involving vasopressors, large volume resuscitation, or long-term infusions.
In routine surgical cases, one or two peripheral IVs are sufficient for anesthetic delivery and hemodynamic support. However, IV lines cannot provide blood pressure readings and lack the ability to sample oxygenated blood without interrupting drug delivery, unlike IA lines.
Intra-arterial lines, commonly inserted into the radial, femoral, or dorsalis pedis artery, are primarily used for real-time blood pressure monitoring and frequent arterial blood gas (ABG) sampling. They are necessitated in the context of major surgeries with expected hemodynamic instability (e.g., cardiac, vascular, transplant), patients in shock, critically ill patients requiring tight blood pressure control or rapid titration of medications, and patients with respiratory failure.
In ambulatory surgery, IV lines are largely sufficient, and the placement of IA lines is generally discouraged unless the procedure unexpectedly escalates in complexity. In ICU settings, IA lines are more common for tight blood pressure and oxygenation control, especially in patients with sepsis, ARDS, or neurologic injury.
IA lines carry higher risks than IV lines. Direct arterial drug injection is avoided as it can cause severe vasospasm vessel wall injury, leading to thrombosis, tissue necrosis, and even limb loss (Lokoff et al 2019). Complications are more common in patients with coagulopathy, peripheral vascular disease, or prolonged catheterization. In these patients, post-operative IA line care must be prioritized. This includes waveform monitoring, dressing integrity, and early detection of ischemic signs in the distal limb.
Ultimately, IA and IV lines serve different but complementary purposes. While IV access remains essential for therapy, IA lines elevate the level of diagnostic clarity and physiologic monitoring when surgical or clinical acuity demands it.
References
Lokoff A, Maynes JT. The incidence, significance, and management of accidental intra-arterial injection: a narrative review. Incidence, importance et prise en charge des injections intra-artérielles accidentelles: un compte rendu narratif. Can J Anaesth. 2019;66(5):576-592. doi:10.1007/s12630-019-01327-6
Tucker WD, Arora Y, Mahajan K. Anatomy, blood vessels. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan–. Updated 2023 Aug 8. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470401/
Ratchagame V, Prabakaran V. Comparison of Risks from Central Venous Catheters and Peripheral Intravenous Lines among Term Neonates in a Tertiary Care Hospital, India. J Caring Sci. 2021;10(2):57-61. Published 2021 May 24. doi:10.34172/jcs.2021.012