Comparison of the success rates of different catheter designs for radial artery cannulation in adult patients undergoing surgery-A randomized trial

There are several types of catheters in usage for radial artery cannulation in cardiac surgical patients. Research is needed to assess the existing catheter designs and develop a catheter with better design for radial artery cannulation in cardiac surgical patients. Although, success rates of different catheter types were compared for peripheral venous cannulation, to the best of our knowledge, there haven’t been any studies done yet to compare these various catheter designs for radial artery cannulation. We believe, this study would through some light in that direction and help in future trials.

  Relevance of the research question and potential clinical applicability of the outcomes

                                       If we can find out the better catheter design for radial artery cannulation, it can be employed uniformly in clinical practice. Catheters with better design are likely to be easy to place with less complications. Patients will be more comfortable and less anxious with better catheter design as it is likely to take less time for placement. It would be very helpful, especially in cardiac surgical patients where tachycardia due to anxiety of the patients is detrimental. We feel, catheter with better design would help in maintaining hemodynamic stability in patients undergoing cardiac surgery, where radial artery cannulation in awake patients under local anaesthesia is a routine.

Background

Cannulation of radial artery is a routine practice in cardiac surgical patients before induction of anesthesia.[1] It allows beat to beat monitoring of blood pressure and as a sampling access to the arterial blood gas monitoring.[2] It also helps in titration of anesthetic medications while maintaining hemodynamic stability which is of prime importance in anesthetic induction of cardiac surgical patients.[3] Although, under local anesthesia, radial artery cannulation in awake patient can cause unwanted anxiety and tachycardia. Various types of catheters are in use for radial artery cannulation in cardiac surgical patients.The objective of this study is to compare the success rates of three commonly used catheters in India for radial artery cannulation, namely arterial leadercath,VYGON-5 rue Adeline 95440 Ecouen-France(Group L), BD arterial cannula, Becton Dickinson Infusion Therapy system Inc, 9450 South state Street, Sandy, Utah 84070,USA(Group B) and ported, winged MAISFLON I.V. cannula, FEP radio-opaque catheter  Boulevard General Wahis 53, B-1030 Brusseis, Belgium(Group I). [Figure 1] Although I.V. cannulas are not supposed to use for arterial cannulation, they have been in use in many centers because of its easy availability and low cost. It should be labelled properly and the injection port on the top of the IV cannula should be closed to prevent inadvertent administration of drugs into arterial system. [4,5]

 Figure 1: Catheters with different designs for radial artery cannulation. (From left to right:  VYGON arterial leadercath, BD arterial cannula, MAISFLON I.V. cannula)

    Methodology including technical description

Type of the study: A prospective randomized trial

Set-up: All India Institute of Medical Sciences, Bhopal which is a tertiary care teaching hospital

Patient inclusion criteria:

1. All adult patients aged 18-65 years of either sex undergoing elective cardiac surgery under general anesthesia who are willing to participate in the trial

Patient exclusion criteria:

1.     Patients with contraindications for radial artery cannulation like local site of infection, gangrene, aneurysms. etc

2.     Chronic Kidney disease patients with arterio-venous fistulas

3.     Patients with bilateral amputated upper limbs

4.     Patients with psychiatric problems who are uncooperative for radial artery cannulation

    This will be a prospective randomised trial conducted on adult patients of either sex, between 18-65 years undergoing cardiac surgery under general anesthesia at All India Institute of Medical Sciences, Bhopal, India. Institutional human ethics committee approval will be obtained before starting the trial. Patient’s information sheet will be handed over to all the subjects three to five days prior to the scheduled procedure. The written and informed consent for the conduct of the study will also be obtained three to five days prior to the surgery from all the subjects, after explaining the procedure. All patients will be given oral tablet alprazolam 0.25 mg on the previous night and on the morning of surgery. Fasting for solids will be for 6 hours and clear liquids will be for 2 hours. All patients will be encouraged to take clear liquids up to two hours prior to surgery.

 Block randomization will be done to allocate the enrolled patients into one of the three groups.  Patients in group L, group B and group I will receive arterial leadercath, BD arterial cannula and ported, winged I.V. cannula respectively for radial artery cannulation. On arrival to the operating room, standard monitors will be attached and baseline recordings of vital parameters will be noted. All the radial artery cannulations will be done under aseptic precautions using local anesthesia(0.5 mL of 2% lignocaine). Physicians having at least 3 years of training in anesthesia will be the operator in all the patients. The technique of insertion will be left to the discretion of the operator. Duration from the point of skin prick to the complete threading of catheter into the radial artery will be defined as “ time taken for cannulation”. Data regarding the number of attempts required for successful radial artery cannulation will be documented. Any complications during the procedure like catheter kinks, catheter tears, needle stick injuries to the operator or any other complication will be noted. Any complications in the post insertion period will also be noted and compared among different catheter designs.

 Sample size and statistical analysis: This, being a pilot project, we are considering a sample size of 40 in each group. Quantitative data will be expressed in mean and standard deviation, qualitative data will be expressed in percentage. P < 0.05 will be considered statistically significant.