Arterial and Central Venous Catheters

Chapter 11 Arterial and Central Venous Catheters



Hovig V. Chitilian, MD




1 What are the indications for intraarterial blood pressure monitoring?




image Inability to obtain noninvasive blood pressure measurements (i.e., burn or multitrauma patient with all extremities affected; during cardiopulmonary bypass; in patients with left ventricular assist devices)


image Need for beat-to-beat monitoring of blood pressure because of patient’s underlying condition


image Need for multiple blood drawings for laboratory testing



2 Which are the common sites for intraarterial catheter placement? What is the effect of the catheter site on the measured blood pressure?


The common sites are the radial, brachial, axillary, femoral, and dorsalis pedis arteries. As the monitoring site is moved further distally in the arterial tree, systolic pressures increase and diastolic pressures decrease when compared with central arterial pressure. The mean arterial pressure, however, remains the same between peripheral and central arterial waveforms.



3 What additional data can be determined from the intraarterial pressure waveform?


In addition to direct pressure measurements, the arterial pressure waveform can be used to determine a patient’s fluid responsiveness, as well as cardiac output. Changes in the arterial pressure waveform with mechanical ventilation have been shown to predict fluid responsiveness (a measurable increase in stroke volume with the administration of fluid). Goal-directed intraoperative fluid management based on arterial waveform changes has been shown to improve outcome in patients undergoing high-risk surgery. In addition, a number of commercially available devices exist that allow the continuous measurement of cardiac output with use of arterial pressure waveform analysis.



4 What are the most common complications of arterial catheterization?


Vascular insufficiency (3%-5%), bleeding (1.5%-2.5%), and infection (< 1%)



5 What are the risk factors for vascular complications in patients with intraarterial catheters?


Concomitant use of vasopressors, prior arterial injury, duration of cannulation longer than 48 or 72 hours, hematoma formation, presence of disseminated intravascular coagulation, reduced cardiac output, and female sex



6 What is the risk of permanent distal ischemic damage?


Studies have suggested that the rate of arterial occlusion is lower in axillary and femoral catheters compared with radial artery catheters; however, the rate of permanent distal ischemic damage is comparable at 0.1% to 0.2%. The incidence of permanent ischemic damage to the hand after radial artery catheterization has been reported to be 0.09%.



7 Is the modified Allen’s test useful?


There is no evidence that the modified Allen’s test (a test of circulatory supply to the hand based on alternating occlusion of the radial and ulnar arteries) can predict hand ischemia with radial artery cannulation.



8 What is the risk of arterial catheter–related bloodstream infection (BSI)?


The incidence of BSIs associated with arterial catheters is 0.8% or 1.7 per 1000 catheter days. Data are conflicting regarding the association of the site of catheterization with risk of infection with some studies suggesting that radial or dorsalis pedis arterial sites are associated with a decreased incidence of BSI when compared with the femoral artery.



9 What measures can be taken to reduce the risk of BSI associated with intraarterial catheters?


The Centers for Disease Control and Prevention do not recommend routine replacement of peripheral arterial catheters at fixed time intervals as a method for preventing catheter-related BSIs. The use of full-barrier sterile precautions (chlorhexidine skin preparation, mask, hat, sterile gloves, gown, and sheet) has not been shown to reduce the risk of bacterial colonization or BSI when compared with the use of hand washing, chlorhexidine preparation, and sterile gloves for the placement of radial or dorsalis pedis arterial catheters.



10 What are the indications for central venous cannulation?




image Monitoring cardiac filling pressures


image Rapid administration of fluid


image Intravenous administration of drugs or fluids that are potentially damaging to peripheral veins or tissues (vasoactive medications, parenteral nutrition)


image Insertion of pulmonary artery catheter or transvenous pacing wires


image Aspiration of air embolus


image Access for hemodialysis or hemofiltration


image Venous access in the instance of difficult peripheral venous access



11 Which veins are commonly used, and how are they accessed?


The most commonly accessed central veins are the internal jugular, the subclavian, and the femoral veins. With use of either anatomic landmarks or ultrasound guidance, the vein is accessed percutaneously with a finder needle of a gauge smaller than the catheter. A guidewire is then passed through the needle and into the vein. The needle is removed, and a dilator is passed over the wire and into the vein to dilate the tissues and venous entry point. The dilator is removed, and the catheter is then passed over the wire and into the vein.

< div class='tao-gold-member'>

Related posts:

Poisoning by Cardiovascular Drugs Mechanical and Noninvasive Ventilation Alcohol Withdrawal Status Epilepticus Hemodynamic Monitoring Thyroid Disease in the Intensive Care Unit

Stay updated, free articles. Join our Telegram channel
Tags:
Jul 6, 2016 | Posted by in CRITICAL CARE | Comments Off on Arterial and Central Venous Catheters

Full access? Get Clinical Tree
Get Clinical Tree app for offline access