Arterial catheterization is a common procedure in medical and
surgical intensive care units (ICUs). Arterial catheters are used
for blood pressure monitoring in hemodynamically unstable patients
and frequent arterial sampling in mechanically ventilated patients;
the arterial line may also have been placed in the operating room
prior to ICU arrival in perioperative patients.
- ▪ Arterial cannulation or catheterization: Insertion
of a catheter into an artery for the purposes of continuous blood
pressure transduction or arterial blood sampling
- ▪ Transducer: An electronic device that converts blood pressure
into an electrical signal translated by a physiologic monitor into
a numeric value—requires a reference, atmospheric value
- ▪ Indications for arterial line placement.
- —Need for continuous (real-time) blood pressure
- —Hemodynamic instability necessitating the use and
titration of inotropes or vasopressors
- —Need for reliable access to the arterial circulation
for measurement of arterial oxygenation, arterial carbon dioxide,
and/or frequent blood sampling
- ▪ Contraindications.
- —Compromised flow distal to cannulation site
precludes cannulation on that side
- —Injury distal to cannulation site
- —Infection in the skin or subcutaneous tissues around
cannulation site (ie, cellulitis)
- —Systemic anticoagulation (relative)
- ▪ Prior to procedure, obtain patient consent, prep and
drape, and perform universal protocol as described in Section I.
- ▪ Identify cannulation site based on patient anatomy and
clinical situation (Figure 35-1 and Table 35-1).
- ▪ Preparation.
- —Skin: The CDC recommends preparation of the
cannulation site with a 2% aqueous chlorhexidine-gluconate
solution, which has been associated with lower blood stream infection
rates than povidine-iodine or alcohol-based preparations. The skin
and tissue around the artery should be infiltrated with 1% lidocaine
solution, except in patients with a known allergy to lidocaine,
in whom alternative local anesthetics can be used.
- —Hygiene: The operator should observe proper hand
hygiene by washing hands with antiseptic soap, gel, or foam prior
to palpation of the cannulation site or insertion, replacement,
manipulation, or dressing of the catheter or site.
- —Equipment: The cannula used for intra-arterial
cannulation is typically a polyurethane or polyethylene catheter.
The catheter size and length is typically determined by the size
and depth of the artery of interest. Shorter, smaller catheters
(ie, 20–22 gauge, 25–50 mm) are typically used
when cannulating arteries in the hands and feet; whereas longer
and thicker catheters (ie, 14–20 gauge, 15–20
cm) are used for larger vessels. The catheter should be connected
to a disposable transducer using noncompliant tubing, which transmits
the arterial waveform to the transducer with optimal fidelity.
- —Operator: The CDC recommends that the operator
wear sterile gloves for the placement of arterial catheters.
- ▪ Methods (see Chapter 34 on vessel cannulation).
- —Direct cannulation (Figures 35-2, 35-3, 35-4, 35-5, and 35-6)
- —Seldinger technique
- —Ultrasound guided
- —Cut down
- ▪ Monitoring: After placement, the catheter is attached
to a pressure transducer zeroed to the level of the right atrium
with high-pressure tubing and tracked ...