RESUMO
BACKGROUND: Radial arterial catheters (RAC) are commonly used in emergency services and intensive care units (ICU) for continuous invasive monitoring of blood pressure and arterial blood gas sampling. Complications associated with RAC are rare. Regarding length of RAC catheters and complications, few studies were found in the literature. The present study seeks to provide health care professionals with scientific evidence to select an optimal length of RAC, based on the difference in the incidence of complications between ultrasound-guided catheters of the same diameter but different lengths. METHODS: Observational, descriptive, retrospective study. Patients older than 17 years admitted to the emergency department or ICU were included. RAC were placed with diameters of 20 gauge, between 5 and 8 cm (Arrow-Teleflex), and 22 gauge diameters between 4 and 8 cm (Vygon). Univariate analysis was made to determine behavior of the numerical variables. Normality of variables was determined through a Shapiro-Wilk-test. Qualitative variables were expressed in percentages, quantitative variables in means and standard deviation, or with median and quartiles in the case of a non-normal distribution. Chi-square or Fisher method was used for qualitative variables and the t-test for symmetric quantitative variables. Asymmetric distributions were processed with the Mann-Whitney U test. A value p < 0.05 was considered statistically significant. The statistical analysis was performed with Stata 14.1 program. RESULTS: About 793 RAC were placed between 2016 and 2019 were included, median age was 60 (37-73) (RIQ) years, 49% male. Complications were reported in all groups on average 17.5%, the most frequent being dysfunction/occlusion of the catheter. Given complications of the same diameter and different catheter lengths, there were no statistical differences between groups. CONCLUSION: Selecting one length or another with a catheter of the same diameter does not have statistically significant differences, in terms of the complications this device may cause-meaning that size does not matter.