Comparison of 14-day catheter-related infection rates between standard and antiseptic-impregnated central venous catheters in intensive care patients
Duse, Adriano Gianmaria
The most frequent life-threatening complication of central venous catheters (CVCs) is septicaemia. Most CVC-related septicaemias derive from invasion of the catheter wound by microorganisms from the patient’s own cutaneous microflora. To decrease the rates of CVC related sepsis, it has been the practice of many intensive care units to re-sito CVCs at specified intervals (e.g., every seven days). However, there is good evidence to suggest that CVCs should remain in place until there is a clinical indication (e.g., fever without a known source) for change. In recent years, antisepticand antibiotic- impregnated catheters have been studied to determine whether they substantially reduce the incidence o f catheter-related infection, extend the time that CVCs can be left in place safely, and are, overall, cost-effective. The purpose o f this study was to compare standard CVCs (ARROW Standard Triple Lumen catheter, Arrow International, Inc., Reading, Pa, US) with chlorhexidine gluconate/silver sulfadiazine-impregnated CVCs (ARROWgard™ Triple Lumen Catheter, Arrow International, Inc., Reading, Pa, US) left in situ for 14 days in adult intensive care unit (ICU) patients. Clinical data were collected and microbiological analyses were performed to determine the following: 1) the epidemiology of CVCrelated infections (CRIs) in the General Intensive Care Unit, Johannesburg Hospital; 2) whether the use o f antiseptic-impregnated (ARROWgard) catheters can significantly decrease the incidence of catheter-related infection as compared to the ARROW Standard CVC at 14 days; and 3) whether the duration of catheter insertion can be safely increased to 14 days. This is the first study conducted in South Africa documenting the epidemiology and rates o f CVC-related infections (expressed per 1000 CVC days) in ICU patients, using the synthesis o f both clinical and microbiological definitions as proposed by the Centers for Disease Control and Prevention (CDC), US. The General ICU of the Johannesburg Hospital is a multidisciplinary unit that admits trauma, medical,gynaecology and surgical patients. Of the original sample of 149 patients receiving CVCs, only 118 CVCs were evaluable. Sixty-two patients received ARROW Standard CVCs and 56 received ARROWgard ™ CVCs. Data presented in this report on the types o f colonising organisms (predominantly skin colonisers) and those causing infections via the transcutaneous route are consistent with those described in other studies. The routes of catheter infection in our patients, viz., mainly transcutaneous and the catheter hub,are likewise well documented in the literature. Molecular techniques (macrorestriction analysis using PFGE) were found to be useful in elucidating the aetiological role of coagulase-negative staphylococci in CRIs. There was no statistically significant difference in total bloodstream infection rates between the group of patients who received ARROW Standard catheters (14.1 CRB s/1000 CVC days) and those who received ARROWgard catheters (10.8 CRBsZ 1000 CVC days). If only primary bloodstream infections are considered (i.e., excluding haematogenous seeding o f the CVC) there is still no statistically significant difference in CRI rates between the 2 catheter groups (12.7 CRTs/1000 CVC days and 8.1 CRTs/1000 CVC days for the ARROW Standard and ARROWgard ™ CVCs respectively). It is pertinent to note that the absence of statistical significance between the 2 groups was noted despite the fact that the ARROW Standard CVC group included more than double the number of trauma patients than the ARROWgard ™ group (20/62 [69%] versus 9/56 [31%] respectively). Furthermore, all patients with an additional intravascular catheter other than a CVC (6/118 [5.1%]) all belonged to the ARROW Standard group. Trauma patients as well as patients with other intravascular devices are, for obvious reasons, more likely to be susceptible to CRTs. Statistical analyses showed, in this study, that it was significant that more than double the number of trauma patients (p = 0.04) and all patients with other intravascular devices (p - 0.016) belonged to the ARROW Standard group with no apparent difference in infection rates in the 2 groups. The mean duration of catheter placement for the full sample of 118 CVCs was 12.31 days. The relatively high rates of CRTs documented in our ICU should caution practitioners against leaving catheters in situ for periods longer than absolutely necessary. Further studies carried out in multi-disciplinary ICUs are required to determine an acceptable range of sepsis rates in this setting. Such studies should also investigate the optimal duration of CVC placement. This study adds to the growing body of literature that suggests that chlorhexidine gluconate/silver sulfadiazine-impregnated CVCs are marginally, if at all, more effective than standard catheters in reducing CRIs. Until such time that more data become available to confirm or refute the anti-infective benefits, and therefore the cost-effectiveness, of chlorhexidine gluconate /silver-sulfadiazine impregnated CVCs, it seems reasonable to reduce CRTs by concentrating on meticulous infection control practice.