Recognition of infection associated with intravenous catheters

Thrombotic and infectious complications of central venous catheters in patients with hematological malignancies

Central venous catheters (CVCs) have considerably improved the management of patients with hematological malignancies, by facilitating chemotherapy, supportive therapy and blood sampling. Complications of insertion of CVCs include mechanical (arterial puncture, pneumothorax), thrombotic and infectious complications. CVC-related thrombosis and infections are frequently occurring complications and may cause significant morbidity in patients with hematological malignancies. CVC-related thrombosis and infections are related and can therefore not be seen as separate entities. The incidence of symptomatic CVC-related thrombosis had been reported to vary between 1.2 and 13.0% of patients with hematological malignancy. The incidence of CVC-related bloodstream infections varies between 0.0 and 20.8%. There is need for a specific approach regarding diagnosis and treatment of CVC-related thrombosis and infection with specific attention to the preservation of the catheter. Since data on CVC-related infections and thrombosis in hematological patients have been obtained mainly from retrospective studies of small sample size, prospective, randomized studies of prophylactic measures concerning CVC-related thrombosis and infection are warranted.

A comparative study of 'Op-site' and 'Nobecutan gauze' dressings for central venous line care

A comparative study of 'Op-site' and 'Nobecutan-gauze' dressings for central venous lines was performed. Seventy-seven long antebrachial and 68 infraclavicular subclavian catheters were studied. A statistically significant reduction in the incidence of positive cultures from the catheter tip and from the skin puncture site was found with the 'Nobecutan-gauze' dressing. No difference in the incidence of catheter-related septicaemia was found. The theoretical advantage of being able to observe signs of inflammation when 'Op-site' was used did not reduce the incidence of local infection at the skin puncture site. In conclusion we found that a 'Nobecutan-gauze' dressing was a satisfactory alternative to an 'Op-site' dressing.

Blood culture as a guide for the diagnosis of central venous catheter sepsis

The purpose of this study was to evaluate the predictability of peripheral (PBC) and central blood cultures (CBC) in the diagnosis of central venous catheter (CVC) sepsis (growth of the same microorganism in the peripheral blood and on the catheter tip). The contamination and sepsis rate of 256 CVCs and the relationship with PBC and CBC was evaluated in a series of cancer patients included in a prospective protocol on CVC infections at the Istituto Nazionale Tumori of Milan. Overall CVC contamination was 10.5% and sepsis rate was 3.1%. The positive predictive value for CVC sepsis was 46.7% for positive PBC + CBC, 38.1% for positive PBC and 16.6% for positive CBC. The small gain in the predictive positive value obtained with the use of PBC and CBC and the slight increase in the specificity does not justify, in our opinion, the use of both these parameters for the diagnosis of CVC sepsis.

Caval catheterization in the intensive care nursery: a useful means for providing parenteral nutrition to the extremely low birth-weight infant

We provided parenteral nutrition to 40 very low birth-weight premature infants (birth weight 815 +/- 17 grams, gestational age 27 +/- 2 weeks) with a superior vena cava catheter. To avoid the risk of transport, catheterization was performed under sterile conditions in the intensive care nursery. The central venous catheter facilitated administration of calories to sustain growth, especially in infants whose catheters remained in place for 3 weeks or longer. The overall incidence of catheter related sepsis was high (30%) but the majority of cases were due to Staphylococcus epidermidis and resolved without incident. Other complications of parenteral nutrition were minimal. This approach is a safe and effective means of providing nutrition to the very low birth-weight infant.

Infection of percutaneous devices: prevention, monitoring, and treatment

Infection continues to pose the major obstacle to long-term percutaneous access. Development of methods to prevent infection or techniques to determine early onset of infection at a time when antibiotic therapy may prove successful would be of enormous value. Our laboratory has been working toward developing and testing a noninvasive semiquantitative swab culture technique (SQ) to monitor percutaneous leads for infection. This technique was found to have a 76% sensitivity having identified 47 of 62 organisms detected by a quantitative tissue culture technique (Q) at the time of system explant. Furthermore, 47 of 61 organisms identified by the SQ technique accurately detected those isolated by the Q techniques. Accordingly, the SQ technique has a 77% specificity. This technique was capable of detecting organisms a median of 14 days prior to overt clinical infection. Prompt initiation of oral antibiotic treatment based on SQ results has doubled system survival compared with untreated systems. Clearly, the SQ technique has proven useful to monitoring percutaneous devices.

Infection and peripheral venous catheterization

A prospective bacteriological and clinical study was carried out to determine the incidence of local and systemic infection associated with peripheral venous catheterization in a 630-bed general hospital with 24 hr intravenous team coverage. In all, 1,696 cannulas were obtained using standardized techniques and were cultured by a semiquantitative method on solid media. 41 cannulas (2.4%) yielded positive cultures (15 or more colonies). An additional 318 (18.8%) showed lesser growth indicative of contamination. No case of septicemia was encountered. Local signs of inflammation showed no correlation with positive cannula culture. The semiquantitative culture technique is easily performed and yields clear results. However, the upper limit for the number of colonies which should be regarded as contamination and criteria for phlebitis require further study. Although the infective risk of peripheral venous catheterization must not be ignored, an extremely low rate can be achieved with continuous IV team coverage and strict aseptic technique.