Invasive arterial blood pressure (IABP) monitoring is critical for perioperative and critically ill patients, yet traditional radial artery cannulation near the wrist joint is prone to catheter dysfunction (e.g., kinking, occlusion) due to positional changes, compromising accuracy and patient safety. This trial hypothesizes that modifying the cannulation site to 1.5-2.5 cm proximal to the radial styloid process may enhance catheter stability.
Methods and analysis:This is a prospective, parallel-group, randomized, controlled, analyst-blinded trial. A total of 486 participants (231 per group, adjusted for 5% dropout) will be enrolled. Eligible patients (18-75 years, ASA physical status I-III, requiring elective surgery with radial artery cannulation) will be randomized 1:1 to the modified group (1.5-2.5 cm proximal to the radial styloid process) or the conventional group (traditional site). The primary outcome is the incidence of arterial catheter dysfunction (defined by criteria such as blood sampling difficulty, position-dependent waveform, or improved waveform post-square wave test). Secondary outcomes include frequency of catheter dysfunction, damping abnormality rate, first-puncture success rate, number of arterial punctures,arterial cannulation time, complication incidence, and blood pressure measurement differences. Sample size calculation:This trial utilized a superiority test for sample size calculation. In the 100-case preliminary experiment results, the incidence rate of abnormal arterial catheter function was 30% in the control group and 12% in the modified group. With a predefined superiority margin Δ of -6% (actual observed Δ of -18%), using a type I error rate (α) of 0.025 and statistical power (1-β) of 0.90, statistical calculations determined that 231 participants per group (totaling 462) would be required to detect this difference in a two-sided test. Considering a 5% dropout rate among study subjects, the final planned sample size was adjusted to 486 cases.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
The ultrasound-guided radial artery puncture site is1.5-2.5 cm proximal to the radial styloid process
The ultrasound-guided radial artery puncture site is level with the radial styloid process and where the radial artery pulse is most prominent
the Sixth Affiliated Hospital, Sun Yat-sen University
Guangzhou, Guangdong, China
RECRUITINGThe Sixth Affiliated Hospital, Sun Yat-sen University
Guangzhou, Guangdong, China
RECRUITINGIncidence of arterial catheter dysfunction
(a) difficulty in blood sampling: When drawing arterial blood samples for blood gas analysis, the sample cannot be aspirated smoothly through the arterial pressure monitoring line, necessitating repeated flushing of the line to obtain an adequate sample; or arterial catheter occlusion occurs and a new arterial pressure monitoring pathway must be established based on surgical or anesthetic requirements; (b) position-dependent waveform or flushing: repositioning of the arterial catheter or wrist is required to obtain a satisfactory arterial waveform, or smooth flushing can only be achieved following such repositioning. (c) improved waveform post-square wave test: after a square wave test (conducted every 30 minutes or when the arterial waveform becomes flat), the arterial waveform shows significant improvement compared to its pre-flush state.
Time frame: during the period of catheter indwelling
Frequency of arterial catheter dysfunction
mean number of catheter instability events per subject per hour.
Time frame: during the period of catheter indwelling
Damping abnormality rate and frequency
Damping abnormality rate: the ratio of total cases with over-damping or under-damping to the total number of enrolled patients per group. Damping abnormality frequency: mean number of over-damping or under-damping events per subject per hour.
Time frame: during the period of catheter indwelling
First-puncture success rate
the ratio of cases with successful first-time arterial cannulation to the number of enrolled cases per group. A successful first puncture is defined as achieving arterial access and catheter placement without needle withdrawal or repositioning after initial skin entry.
Time frame: From the start of arterial puncture until successful arterial catheter placement or abandonment of the arterial catheter placement procedure,up to 10 minutes
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Enrollment
486
Number of arterial punctures
total number of arterial punctures performed before successful cannulation. One puncture is defined as withdrawing the needle to the subcutaneous layer and reinserting it during the cannulation process.
Time frame: From the start of arterial puncture until successful arterial catheter placement or abandonment of the arterial catheter placement procedure,up to 10 minutes
Arterial Cannulation Time
defined as the interval from the first skin entry of the needle to the first display of an arterial blood pressure waveform on the monitor.
Time frame: From the start of arterial puncture until successful arterial catheter placement or abandonment of the arterial catheter placement procedure,up to 10 minutes
Complication incidence
encompasses complications during puncture and catheter indwelling (e.g., hematoma, bleeding, ecchymosis) and post-puncture complications (e.g., bleeding, hematoma, distal ischemia, local infection, peripheral nerve injury, unintended catheter dislodgment). The observation window is 0-3 days post-surgery.
Time frame: from the time of the puncture onset until the time of every day after arterial puncture (at 1-day, 2-day, 3-day
Difference in IABP before and after square wave test.
The difference between the invasive blood pressure value before wave test and the invasive blood pressure value after waveform stabilization
Time frame: during the period of catheter indwelling
Difference between IABP and NIBP
The difference between the invasive blood pressure value and the cuff pressure after waveform stabilization
Time frame: during the period of catheter indwelling