Abstract
The use of venous catheters is essential in critical care units. Their use is not risk free, especially from catheter-related infections, which have a significant associated morbidity and mortality. Knowing the relevance of the endoluminal route in the pathogenesis of sepsis from catheters, the aim of these studies is to observe the security of a new needle-free disinfectable connector (Smartsite, Alaris Medicals Systems, San Diego, California 92121, USA) in experimental and clinical conditions.
Description of the disinfectable connector.
The Smartsite connector is a needle-free device with a silicone valve, which becomes permeable when compressed by a syringe or any luer-type connector. The peculiarity of this system comes from the possibility of disinfect easily the external surface of the device by swabbing it with a gauze with antiseptic before handling.
Experimental evaluation An experimental trial was designed in which a laboratory model simulated the insertion of a peripheral venous catheter. This model consisted in two groups of 25 bottles of aerobic hemoculture (Bact Alert) into which an 18G peripheral venous catheter (Venflon) was inserted and closed with disinfectable needle-free connectors (study group) or conventional caps (control group). Five catheters from each group were left untouched to evaluate the sterility of the system without handling. In the remaining catheters, after the third day of insertion, the external surfaces of the disinfectable connectors and the caps were daily contaminated with S. Aureus. Five hours after each contamination, one cubic centimeter of sterile saline was injected.
A sensor in the bottom of the bottle changed its colour if it was contaminated, detecting the CO2 produced by the growth of the bacteria. Once positive, the liquid in the bottle was examined to identify the microorganism.
There was no infection in the fifty bottles in the first three days and there was no contamination in the 10 untouched models of the two groups of the study. Fifty per cent of the bottles were colonized in the fifth day in the control group and in the eleventh day in the study group. All control group bottles were colonized by the ninth day while 40% of the study group bottles were still sterile at the end of the study, after 18 days of handling. The survival curves of both groups show a significant difference (p<0.001).
Clinical evaluation.
A randomized controlled trial was performed in a polyvalent Intensive Care Unit to assess the efficacy of the disinfectable needle-free connector in the prophylaxis of catheter-related bloodstream infection. Patients who needed multilumen central venous catheters were assigned at random to study or control group. All catheters were inserted and manipulated according with the CDC96 recommendations. Catheters of patients of the study group were equipped with disinfectable needle-free connectors whereas catheters of patients of control group catheters were equipped with three-way stopcocks.
Two hundred forty three patients were included, with a total of 278 central venous catheters (139 in each study group). The mean insertion length of catheters was 9.9 days. Both groups were statistically comparable regarding patients and catheters characteristics. Incidence rate of catheter-related bloodstream was 0.7/1000 days of catheter use in the study group, in comparison with 5.0/1000 days of catheter use in the control group (p = 0.03). The multivariate logistic regression analysis identified age, obesity, number of days in ICU and the use of three-way stopcock as independent risk factors for catheter-related bloodstream.
Conclusion.
The needle-free disinfectable Smartsite connector has shown more resistance to the pass of microorganisms to catheter lumen than conventional caps in the extreme conditions of the described experimental model.
To add a disinfectable needle-free connector to the CDC recommendations reduces significantly the incidence of catheter-related bloodstream in central venous catheters inserted in critically ill patients.
| Date of Award | 1 Apr 2003 |
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| Original language | Spanish |
| Supervisor | Mercedes Palomar Martínez (Director) |