Intra-arterial catheters: An evidence-based review of device design, function and application

Table 1 Approximate dimensions for needles, wires and cannulae utilized in arterial catheterization; note that minor variability exists between manufacturers, products, and measurement systems

Needle or catheter gauge	Needle or catheter outer diameter (mm)	Matching guidewire thickness (inches)	Gravity flow rate (mL/minute)
22G	0.7-0.9	0.014	35
21G	0.8-0.9	0.018	60
20G	0.9-1.1	0.025	65
18G	1.2-1.3	0.035	100

Table 2 Characteristics of common commercially available arterial line products; these examples represent classic dimensions but many size combinations are available

Product	Pink BD Insyte	Blue BD Insyte	Vygon Leadercath	Arrow Quickflash	Arrow Integrated	Arrow Seldinger	BD Floswitch
Assembly style	CN	CN	S	IW	IW	S	CN
Intended insertion site	Radial	Radial	Radial	Radial	Radial	Femoral	Radial
Catheter material	Polyurethane	Polyurethane	Polyethylene	Polyurethane	Polyurethane	Polyurethane	Polyurethane
Catheter gauge	20G	22G	20G	20G	20G	18G	20G
Catheter length (cm)	3	2.5	8	3.8	4.5	16	4.5
Introducer needle gauge	21G	23G	20G	21G	22G	18G	21G
Introducer needle length (cm)			3.8			7
Guidewire material			Stainless steel	Stainless steel	Stainless steel	Stainless steel
Guidewire gauge (inches)			0.021	0.018	0.018	0.025

CN: Catheter-over-needle; S: Seldinger; IW: Integral-wire modified Seldinger.

Table 3 Important aspects in the daily care of arterial lines

Daily care	Explanation
Dressings	The optimal dressing products, frequency of dressing changes and frequency of site inspections are uncertain. A common practice is to replace dressings weekly or sooner if they become loose or unclean. Local institutional policies should be followed. A topical cleansing agent should be applied to the catheter site during a dressing change to prevent infection[76,83]
Antibiotic prophylaxis	Daily antimicrobial prophylaxis to prevent infection while the arterial line is in situ is not advised, as evidence is insufficient
Securement	Both sutures and adhesive dressings are suitable methods for catheter securement. No consistent differences in adverse events have been demonstrated[84]. Sutures were associated with fewer arterial line displacements in retrospective studies compared with sutureless fixation dressings but may predispose to infection
Flushing	A continuous slow infusion of normal saline is delivered through the arterial line to maintain patency. A pressure bag attached to the transducer system is commonly inflated to 300 mmHg to deliver fluid at a rate of ~3 mL/hour. This configuration reduced adverse events compared with intermittent flushes or infusion rates[85,86]. Heparin does not improve patency over normal saline[87]
Routine catheter changes	Routine arterial line changes are not recommended. Regular arterial line replacement does not reduce the risk of catheter-related sepsis as opposed to a process of replacement only when clinically indicated[88-90]. The relationship between catheter dwell time and the incidence of infection is unclear