Critical Care Vascular Access: ICU Device Selection, Arterial Lines, and High-Acuity Protocols

The ICU patient presents the most complex vascular access scenario in clinical medicine: multiple simultaneous access needs, hemodynamic instability that precludes repositioning or waiting, coagulopathy that complicates insertion, high-acuity medications (vasopressors, high-concentration electrolytes, insulin drips) that mandate central venous access, and extended CVAD dwell times in a patient population with maximal CLABSI susceptibility. Managing vascular access in critically ill patients is as much a patient safety discipline as it is a technical skill.

Parent guide: Vascular Access Special Populations: Complete Reference

The ICU Vascular Access Landscape

A complex ICU patient may simultaneously require:

• Central venous catheter (CVC): For vasopressors, concentrated electrolytes, TPN, central venous pressure (CVP) monitoring
• Arterial line: For continuous blood pressure monitoring and frequent arterial blood gas sampling
• Dialysis catheter: For CRRT (continuous renal replacement therapy) or intermittent hemodialysis
• Pulmonary artery catheter (PAC): In selected cases for hemodynamic monitoring
• Peripheral IVs: For medication administration, volume resuscitation, and access redundancy

Understanding which access type is required for which purpose — and how to sequence device placement in an unstable patient — is a core critical care competency.

Central Venous Catheter in the ICU

Site Selection: CDC and Clinical Recommendations

Site priority for non-tunneled CVC in the ICU (CDC Guidelines for CLABSI Prevention):

1. Subclavian vein (first choice for CLABSI prevention): Lowest CLABSI rate among non-tunneled CVC insertion sites in meta-analyses. However, highest risk of pneumothorax (1–3%); not suitable in patients with coagulopathy, emphysematous bullae near the apex, or contralateral pneumothorax.

2. Internal jugular (IJ) vein (second choice): Lower pneumothorax risk than subclavian. Higher CLABSI rate than subclavian. Preferred when coagulopathy is present (site is compressible if arterial injury occurs). Right IJ is most direct path to SVC/RA.

3. Femoral vein (avoid when possible): Highest CLABSI rate; highest DVT rate; access site contamination with perineal/fecal flora. Avoid femoral access unless upper body access is impossible. If femoral CVC is placed emergently, plan for earliest possible replacement with IJ or subclavian access.

Exception to femoral avoidance: Femoral CVC is appropriate and preferred in:

• Cardiac arrest (upper body access interferes with CPR)
• Patient position prohibiting upper body access (severe burns, prone positioning, surgical field constraints)

Ultrasound Guidance for ICU CVC Insertion

Routine ultrasound guidance for CVC insertion is a standard of care in the ICU (TJC, AHRQ, CDC). Real-time ultrasound guidance reduces:

• Arterial cannulation risk (from ~3% to <0.5% for IJ CVC)
• Pneumothorax risk for IJ CVC
• Failed placement attempts
• Time to successful placement in a hemodynamically unstable patient

IJ CVC ultrasound technique: Real-time short-axis (transverse) visualization of the IJ vein for needle guidance. The IJ lies lateral to the common carotid artery — compressibility differentiates them. Valsalva maneuver or Trendelenburg position distends the IJ to improve target size.

Multi-Lumen CVCs in the ICU

Most ICU patients require multi-lumen CVC (triple or quadruple lumen) to accommodate simultaneous infusions. Dedicated lumen assignment reduces medication incompatibilities:

Standard lumen assignment (varies by institution):

• Proximal lumen: Vasopressors, vasodilators — medications where flow rate precision matters
• Medial lumen: High-risk medications (heparin, insulin), TPN
• Distal lumen: Blood sampling, CVP monitoring, volume administration

Lumen selection principles:

• Never mix incompatible medications in the same lumen
• Use the smallest number of lumens that meets clinical needs — each lumen is a separate access event and CLABSI risk
• Document lumen assignments in nursing notes
• Reassess lumen necessity daily — remove CVC as soon as clinically no longer required

ICU CVC Dwell and Necessity Review

Daily necessity review is mandatory for every CVAD in the ICU. This is part of the CLABSI maintenance bundle and a TJC expectation.

The question: “Does this patient still need this catheter? In this location? At this number of lumens?”

Documentation: Most institutions require daily documentation that CVAD necessity was assessed. Some use formal checklists; others use a nursing note field or electronic prompts.

Arterial Lines in the ICU

Indications for Arterial Line Placement

Continuous arterial blood pressure monitoring is indicated when:

• Vasopressors are being administered (blood pressure changes are rapid; cuff monitoring is inadequate)
• Hemodynamic instability requires real-time pressure data to guide resuscitation
• Frequent arterial blood gas sampling (>4 per day) is anticipated
• Large-volume surgery or procedural resuscitation is anticipated

Arterial Line Sites in Order of Preference

Radial artery (dominant wrist) is first choice for most ICU patients. Perform modified Allen test (occlude both radial and ulnar while patient makes a fist; release ulnar — hand should flush within 5–7 seconds, confirming collateral flow) before radial cannulation.

Arterial Line Insertion Technique (Radial)

1. Position wrist in dorsiflexion with support roll under wrist; sterile prep with CHG/IPA
2. Palpate radial artery at 1.5 cm proximal to the radial styloid
3. Insert 20G IV catheter at 30–45° angle; advance until flash of blood in hub
4. Lower angle and advance catheter while withdrawing needle
5. Connect transducer tubing; confirm arterial waveform (pulsatile, systolic > diastolic)
6. Secure catheter; apply transparent dressing
7. Do not aspirate from arterial line without first disconnecting from pressure transducer — aspiration against a pressurized system can draw air into the line

Ultrasound guidance for arterial line: Increasingly used for difficult radial access (hypotension, small body habitus, obesity, failed attempts). Short-axis in-plane technique; the artery is non-compressible, pulsatile, and round — distinguish from radial vein.

Arterial Line Management and Complications

Continuous transducer flushing: Pressurized flush system (300 mmHg pressure bag) with heparinized or non-heparinized saline (3 mL/hr) maintains catheter patency.

Zeroing the transducer: Level transducer at the phlebostatic axis (fourth intercostal space, midaxillary line) for accurate pressure readings. Zero the transducer after repositioning the patient, at the start of each shift, and after any transducer manipulation.

Complications:

• Thrombosis/occlusion: Most common; managed with removal; thrombolysis is not appropriate for arterial catheters
• Distal ischemia: Absence of pulse distal to arterial line, blanching, pain — emergent catheter removal required
• Infection: Arterial catheters have lower CLABSI rates than CVCs; change arterial line tubing per institutional policy (typically 96 hours per INS)
• Hemorrhage: Accidental disconnection of arterial line can result in rapid, large blood loss; all connections must be Luer-locked

Arterial line dwell: Change site if any evidence of infection, occlusion, or distal ischemia. INS recommends against routine replacement at fixed intervals without clinical indication (same principle as CVC).

Vasopressor Access in the ICU

Central Access for Vasopressors

Vasopressors (norepinephrine, dopamine, vasopressin, phenylephrine, epinephrine) are vesicants — extravasation causes ischemic tissue necrosis via vasoconstriction mechanism. Standard ICU practice requires central venous access for vasopressors expected to run more than 6 hours.

Emergency peripheral vasopressor: In the setting of septic shock before central access is achieved, peripheral vasopressor administration through a large antecubital vein is acceptable as a short-term bridge:

• Site: forearm or antecubital, preferably antecubital (largest veins, highest flow)
• Concentration: use lowest effective concentration (norepinephrine ≤8 mcg/mL; dopamine ≤3,200 mcg/mL)
• Duration: transition to central access as soon as possible; typically <6 hours peripheral vasopressor
• Monitoring: every 30 minutes; nurse dedicated to frequent site assessment
• Phentolamine available at bedside

Key evidence: Multiple observational studies have demonstrated the safety of short-term (<6–12 hours) peripheral vasopressor administration in appropriately monitored patients without increased extravasation injury vs. central administration. The key variable is monitoring intensity, not route alone.

CRRT and Hemodialysis Access in the ICU

Critically ill patients with acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) or intermittent hemodialysis (IHD) need a dedicated large-bore dialysis catheter — not a standard CVC.

Dialysis catheter requirements:

• 12–14 Fr dual-lumen (standard CVC of 7–8 Fr cannot achieve the 200–350 mL/min blood flow required for CRRT)
• Tip position at IVC-RA junction (femoral insertion) or RA/SVC-RA junction (jugular insertion)
• Right IJ insertion preferred — most direct path, lowest dysfunction rate

Site considerations for CRRT catheter in the ICU:

• Right IJ: preferred; does not conflict with groin access, can be placed without patient repositioning if patient is supine
• Femoral: second choice; useful when IJ access is not feasible (neck anatomy, prior procedures, patient intolerance of positioning)
• Subclavian: avoid in ESRD/CKD patients (central venous stenosis risk) and when respiratory status is precarious (pneumothorax risk)

Do not use a dialysis catheter for non-dialysis medications — dialysis catheters are high-thrombosis-risk, high-CLABSI-risk devices; every unnecessary access event increases risk. Lock the catheter between dialysis sessions with heparin or citrate per protocol.

Pulmonary Artery Catheter (PAC)

The pulmonary artery catheter (Swan-Ganz catheter) provides hemodynamic data including:

• Pulmonary artery pressure (PAP)
• Pulmonary capillary wedge pressure (PCWP) — surrogate for left atrial pressure / left ventricular preload
• Cardiac output (via thermodilution)
• Mixed venous oxygen saturation (SvO₂)

Indications: Cardiogenic shock, severe heart failure, complex hemodynamic management where non-invasive assessment is insufficient, high-risk cardiac surgery (institution-specific).

Declining use: PAC use has declined significantly in the last two decades. Multiple randomized trials (ESCAPE, PAC-Man) failed to demonstrate mortality benefit of PAC-guided management over standard care for most ICU indications.

Insertion approach: PAC is inserted through a large-bore sheath (introducer catheter, typically 8.5 Fr) via IJ, subclavian, or femoral vein. The catheter is balloon-tipped — after insertion into the central venous system, the balloon is inflated and the catheter “floats” through the right heart into the pulmonary artery, guided by characteristic pressure waveforms (CVP → RV pressure → PA pressure → wedge pressure).

Complications: Ventricular arrhythmias during passage through the right ventricle; pulmonary artery rupture (rare, fatal); catheter knotting; infection. Balloon should never be inflated more than wedge measurement intervals (rupture risk from sustained inflation).

CLABSI Prevention in the ICU: Unique Considerations

The ICU is where CLABSI prevention bundles originated (the Keystone ICU project in Michigan demonstrated that comprehensive bundle implementation reduces CLABSI rates to near-zero in ICU settings). The standard CLABSI insertion and maintenance bundles apply, with ICU-specific emphasis:

Insertion bundle compliance in emergency situations: When a CVC is inserted emergently without full sterile technique (e.g., cardiac arrest, rapid deterioration), the catheter should be removed or exchanged over a wire with full sterile technique within 24–48 hours when the patient is stable.

CHG daily bathing: Most evidence for daily CHG bathing comes from ICU studies (Climo 2013 NEJM, Bleasdale 2007). ICU patients on daily CHG bathing have 28% lower CLABSI rates. Daily CHG bathing should be standard in any ICU where CLABSIs occur.

Catheter burden: ICU patients may have 3–4 vascular access devices simultaneously. Every catheter must have documented daily necessity review. Removing any single device that is no longer necessary reduces total CLABSI risk.

Catheter hubs in the ICU: Hub access frequency in the ICU is dramatically higher than ward patients — vasopressors, insulin drips, sedation, and analgesics all require multiple daily hub manipulations. Passive disinfection caps on all CVC lumens that are not in continuous use reduce hub contamination burden.

Simultaneous Device Management in the ICU: Practical Framework

Related Resources

Related guides:

• Non-Tunneled CVC Guide
• CLABSI Insertion Bundle
• CLABSI Maintenance Bundle
• Vesicant Administration Safety
• Vascular Access Special Populations

References

1. Gorski LA, et al. (2021). INS Infusion Therapy Standards of Practice (Standards 26–27, 34, 40). J Infus Nurs, 44(Suppl 1).
2. O’Grady NP, et al. (2011). CDC Guidelines for Prevention of Intravascular Catheter-Related Infections. MMWR, 60(RR-1).
3. Pronovost P, et al. (2006). An intervention to decrease catheter-related bloodstream infections in the ICU. N Engl J Med, 355(26):2725–2732.
4. Climo MW, et al. (2013). Effect of daily chlorhexidine bathing on hospital-acquired infection. N Engl J Med, 368(6):533–542.
5. Ricard JD, et al. (2013). Subclavian or internal jugular central venous catheter — which is more efficient? Crit Care Med, 41(7):1760–1765.
6. Loubani OM & Green RS. (2015). A systematic review of extravasation and local tissue injury from administration of vasopressors through peripheral intravenous catheters. J Crit Care, 30(3):653.e9–653.e17.