Risk factors for complications in peripheral intravenous catheters in adults: secondary analysis of a randomized controlled trial

ABSTRACT Objective: analyze the risk factors linked to complications in peripheral intravenous catheters. Method: secondary data analysis of a randomized controlled trial with 169 medical and surgical patients placed in two groups, one with integrated safety catheter (n=90) and other using simple needle catheter (n=79), with three months follow-up time. Results: the risk factors that raised the odds of developing complications were: hospitalization between 10-19 days (p=0.0483) and 20-29 days (p=0,0098), antimicrobial use (p=0.0288) and use of fluid solutions (p=0.0362). The 20 Gauge lowered the risks of complications (p=0.0153). Multiple analysis showed reduction of risk for the 20 Gauge (p=0.0350); heightened risk for solutions and fluids (p=0.0351) and use of corticosteroids (p=0.0214). Conclusion: risk factors linked to complications in peripheral intravenous catheters were: hospitalization periods between 10-29 days, antimicrobial infusion, solutions and fluids and corticosteroids. Regarding complications, 20 Gauge is a protecting factor compared with 22. Brazilian Clinical Trials Registry: RBR-46ZQR8.


Introduction
Intravenous therapy is commonly used in hospitals, by inserting peripheral intravenous catheters.
Most catheters are removed due to the occurrence of complications, end of treatment or absence of use (1) .

The estimated annual use is about 200 million catheters
in the United States of America (USA) (2) . In Spain, approximately half of hospitalized patients receive an intravenous catheter, being 95% of them peripheral (3) .
More than 70% of patients admitted to hospitals require peripheral intravenous catheters (2) . Other studies show the use of peripheral venous catheters in 86.4% (4) and 80.6% (5) of the patients.
In spite of this extended use, the use of peripheral venous catheters can lead to complications such as phlebitis, obstruction, seepage, leakage and accidental removal (6) , resulting in increased hospitalization and treatment costs, and patient discomfort (1) . Understanding the risk factors for developing complications can facilitate the task of daily care of the nursing team, and may help to produce knowledge and scientific evidence to support the decision making of the nurses geared towards minimizing the risk of peripheral intravenous therapy.
Thus, the general purpose of this secondary analysis was to analyze the risk factors related to the occurrence of complications in the peripheral venous catheterization and the specific objective was to compare the incidence of complications according to the type of peripheral venous catheter used: integrated safety catheter and simple needle catheter. The main study, from which this secondary analysis was derived, consisted in a randomized clinical trial that analyzed the complications arising from the use and type of peripheral venous catheters in adults (7)(8) .

Methods
This is a secondary analysis of a randomized clinical trial, in which randomization occurred by systematic random sampling, in two groups: integrated safety catheter and simple needle catheter. The integrated safety catheter consists of a silicon covered needle with double angle, tri-faceted bezel connected to the mandrel through metal guide and handle; made of polyurethane biomaterial; it has full protection of the needle device, activated after the puncture; wings with slots; transparent vinyl extender tube; bio-selective reflux chamber filter cover; fast cutting clamp; twoway access composed of female "Y" connector, one a Luer-Lok ® connection and another with removable male plug device. The short flexible catheter is of the needle type, with internal safety device (triggered passively) and

Results
The study include 193 eligible participants, from them 15 were excluded from the data analysis (18 G (Table 1), but a minority of antibiotics, electrolytes, anticoagulants, vesicant drugs and corticosteroids were also used. Regarding the time of use, the majority of inserted catheters remained a time equal to or exceeding 72 hours (Table 1). Among the reasons for withdrawal, hospital discharge, followed by phlebitis were predominant. (Table1).    (Table 3).
Cumulative risk rates were estimated for all complications in the same manner for the four more frequent complications in this study. There was no significant difference between the curves (Figure 1).
However, it was noted that after the third day, the risk in the group that used the integrated safety catheter is progressively shrinking, when compared to the group using simple needle catheter. There was similarity between the risks of phlebitis up to four days with the catheter, but from the fifth day on, phlebitis risk rate in the group with simple needle catheter was close to 2.0, while in the group with integrated safety catheter was 1.0. The cumulative risks rates for seepage are almost equal up to the second day, but after the third day the risk rate in the group with integrated security catheter was close to 0.5 while being 1.1 in the control group.
In the case of obstructions, the cumulative risk rate is higher in integrated safety catheter group from the first day of puncture. Cumulative risk rates are lower related to develop traction in the integrated safety catheter group, and were were noticeable from the second day of placement of the catheter (Figure 1).
Similar rates of complications in the peripheral venous catheterization are found in 52% (9) and 51.1% (3) of catheters.  (18) . In the cumulative risk analysis it was perceived that the risk to develop complications in the integrated safety catheter group was increasingly smaller after the third day as compared to the simple needle catheter group.
By comparing the catheters that developed phlebitis with catheters developing other complications, having the catheter for more than 72 hours in place showed itself as a factor that increases risk. A study, linking the catheter time in the vein with phlebitis identified the development of this condition in 28% of catheters between the fourth and fifth days of stay (p = 0.03) (19) .
Another study showed that the probability of phlebitis development increases by 5% every 24 hours the catheter remains inserted in the patient (15).
Related to the length of time passed with the catheter inserted, the multiple analysis of a study result in an Odds Ratio (OR) of 1.010 for periods longer than 72 hours (p < 0.001) (12) . Other authors say that a catheter inserted for less than 48 hours and by 49 to 96 hours has a positive risk of phlebitis of 5.8 (p = 0.000) and 2.8 (p = 0.002) respectively when compared to the period 97-120 hours (17) . A binary logistic regression showed an OR of 2.72 (p = 0.000) when the catheter is inserted for more than 48 hours (20) , to those placed in the back of the hand (15) . Another study differs, referring that insertion in the forearm and arm compared to hand/wrist increases the risk of phlebitis by 1.53 (p = 0.024) (18) . A logistic regression analysis carried out in 2013 showed a reduction of the risk of phlebitis by 0.32 (p = 0.038) for catheters placed in upper limbs (21) . The stay of patients in orthopedic clinic (OR = 0.53, p = 0.034) and surgical wards (OR = 0.61, p = 0.041) reduce the risk of phlebitis when compared to those admitted to Medicine units (15) .
Presence of diabetes as comorbidity increased the chances of phlebitis (OR = 2.42; p = 0.011) (20) . A gauge 18G or wider catheter increased the risk of phlebitis by 1.48 (p = 0.014) (1) , as well as the presence of an infectious process in the patient (RR = 1.41, p = 0.022) (1) . The use of antimicrobial agents was also an increased risk factor for phlebitis by 1.48 (p < 0.01) (1) 1.87 (p = 0.013) (21) and 2.4 (p = 0.002) (17) . The infusion of other drugs reduced the risk of phlebitis in 0.79 times (p = 0.009) (1) , but comparing the infusion of drugs with hydration solutions, there is an increased risk of 1.55 (p = 0.02) (18) .