INTRODUCTION

Continuous arterial pressure monitoring and direct arterial blood samplings are the two most common indications for arterial catheterization, which is typically used for perioperative monitoring during major surgical procedures and in critically ill patients. Common sites of cannulation include radial, femoral, and axillary arteries, and the most frequently reported complications include vascular insufficiency, bleeding, and infection. Despite reported complications, numerous studies have demonstrated the safety of arterial cannulas for monitoring in both the surgical and the medical intensive care settings.¹ In an extensive review of the literature from 1978 to 2001, Scheer and coworkers¹ reported a major complication rate of less than 1% in over 25,505 attempts at cannulation of the radial, femoral, and axillary arteries.

INDICATIONS

• Continuous arterial pressure monitoring

• Direct arterial blood sampling

OPERATIVE PROCEDURE

Radial Artery Cannulation

Scheer and coworkers ¹ found temporary occlusion of the radial artery to be the most common complication, with an incidence rate from 1.5% to 35%. Complications after radial cannulation have also been reported: hematoma formation (14% incidence rate), local infection (0.7%), bleeding (0.5%), pseudoaneurysm (0.09%), and permanent ischemic damage (0.09%).¹

Thrombosis

• Consequence

Occlusive complications plague all of the common sites for arterial cannulation. Arterial spasm and pulseness are more commonly seen after new-site insertion, whereas vascular insufficiency and bleeding were more common after line changes over a guidewire.²

Grade 1/2 complication

• Repair

Catheter removal is typically sufficient therapy except in extreme circumstances, as noted under “Pseudoaneursym,” later in this chapter.

• Prevention

Thrombotic complications can be avoided and minimized through the use of smaller-gauge catheters (20-gauge) and Teflon catheters.³ Minimizing the number of punctures has also been shown to be an effective means of minimizing the chance of thrombotic complications.⁴ Slogoff and associates⁴ also demonstrated an increased risk of occlusive complications in patients who also have hematoma, which is also related to multiple puncture attempts. Beards and colleagues⁵ in a randomized, controlled trial demonstrated that arterial cannula insertion using a Seldinger technique resulted in fewer puncture attempts and fewer occlusive problems than a direct puncture method of cannula insertion. Similarly, Mangar and coworkers⁶ demonstrated an 82% success rate when cannulating the radial artery using a guidewire versus only 65% success when a direct puncture method was used. The use of heparinized flush solution made no difference in the maintenance of cannula patency versus flushing with normal saline; however, more accurate blood pressure monitoring was recorded in patients receiving heparinized flush solutions than in those with cannulas flushed with normal saline only.⁷ Low-dose aspirin or low-dose heparin therapy pretreatment has been demonstrated to minimize the risk of occlusive complications after arterial cannulation.⁸

Infection

• Consequence

Whether or not cannula site influences infection rate after arterial cannulation is controversial. Frezza and associates ² found that the infection rate of 0.4% to 0.7% does not vary regardless of line site and that serial changing of the arterial cannulation site made no difference in terms of the complications reported. However, in a large prospective observational study, Lorente and coworkers ⁹ demonstrated a higher risk of catheter-related line infections and catheter-related bloodstream infections with femoral arterial cannulas than with radial cannulas.⁹

Grade 1 complication

• Repair

Appropriate antibiotic therapy and catheter removal will typically provide sufficient therapy.

• Prevention

Sterile insertion technique, adequate disinfection of cannulation site, and length of cannulation have been demonstrated to be crucial factors for decreasing the incidence of cannula-related infections.¹⁰ Mimoz and colleagues¹⁰ compared the use of chlorhexidine with iodine preparation solutions for both sterilization of the insertion site and maintenance of indwelling cannula sites in a prospective, randomized trial and found that the chlorhexidine solution was more effacious at prevention of infection at cannula sites. This effect was attributed to chlorhexidine’s effect on gram-positive organisms.¹⁰