Table 3.

Puncture site, cannulation time, number of attempts, and complications during arterial cannulation

Parameter	Group C (n = 38)	Group E (n = 38)	P value
Puncture site (left/right)	34/4	35/3	0.500
Cannulation time (seconds)	19 (13–24)	15 (11–19)	0.099
Number of attempts (1/≥2)	30/8	36/2	0.042
Posterior wall puncture, n (%)	8	1	0.028
Haematoma, n (%)	8	1	0.028
Thrombosis, n (%)	0	0	–

Values are expressed as the median (interquartile) or the number of patients. Cannulation time is defined as the time taken from the initial skin puncture to the successful arterial catheter insertion; the number of attempts is defined as the number of new skin punctures required to puncture the radial artery. A posterior wall puncture is defined when the withdrawal of blood in the needle stopped after confirming the presence of occult blood while advancing the needle or when pulsatile blood appeared during the withdrawal of the needle; a haematoma is defined as a solid swelling of clotted blood around the artery confirmed by ultrasound. A thrombosis is defined as the local coagulation or clotting of blood in the artery confirmed by ultrasound