The purpose of the study is to evaluate the impact of arm abduction and adduction on the intravascular electrocardiograph during PICC placement and to find out how arm position influences the catheter tip location by taking postprocedural chest X-ray radiographs.

PICC has been widely applied for therapeutic and nutritional use. In the routine procedure of PICC placement, for better exposure of the punctured vein and a wider aseptic area, the PICC set is investigated with the patient's arm abducted in a supine position. While in actual use of the PICC line, patients commonly prefer a more comfortable position with arm adducted. Considering the incorporation of the arm position when the catheter is placed and being used, the effectiveness and safety of the PICC line with the punctured arm adducted are of practical importance.

This study aims to evaluate the impact of arm abduction and adduction on the intravascular electrocardiograph (ECG) during ECG-guided PICC placement and to explore how arm movement (from abduction to adduction) makes an influence on the catheter tip position.

This study is expected to enroll 150 participants. All participants would undergo the procedure of ECG-guided PICC placement. ECG data will be recorded before the procedure (basal ECG) and during the procedure with the punctured arm abducted and adducted. After the procedure, participants will take a post chest X-ray confirmation with arms adducted and abducted in a supine position. The catheter tip position and influences of arm movements will be calculated by the distances from the catheter tip to the carina on radiographs.

Inclusion Criteria:

• indication for PICC placement
• able to corporate with the operator during the procedure
• a recognizable P wave on basal ECG

Exclusion Criteria:

• bedside PICC placement
• Atrial fibrillation or other atrial arrhythmia's in which a P wave was not consistently present on ECG.
• with pacemaker
• unable to move to take post-procedural chest X-ray radiographs
• unable to move the punctured arm or can only move with limited angles due to anatomical abnormalities or personal/medical equipment or surgeries.
• catheter tip cannot be clearly visible on chest X-ray radiograph due to thoracic abnormalities or cardiothoracic surgeries.