A study to determine the minimum volume of blood necessary to be discarded from a central venous catheter before a valid sample is obtained in children with cancer

Northern Institute for Cancer Research, University of Newcastle upon Tyne, Newcastle upon Tyne, NE2 4HH, United Kingdom.
Pediatric Blood & Cancer (Impact Factor: 2.56). 06/2007; 48(7):687-95. DOI: 10.1002/pbc.20873
Source: PubMed

ABSTRACT The objective of this study was to determine the minimum volume of blood that should be discarded from a range of different types of central venous catheter (CVC), such that the subsequent blood sample was not diluted or contaminated by the residual intra-luminal fluid.
Seventy children aged 1-19 years with central venous access inserted as part of their standard clinical treatment were recruited to this prospective study. Statistical comparison of the extent of variation in biochemical and haematological parameters observed between two blood samples taken following routine 5 ml discard blood volumes, as compared to the extent of variation between samples drawn following a 5 ml discard volume and <5 ml volumes, was carried out.
Data indicate that the measurement error in a clinical sample obtained following a 3 ml discard volume is no different to the measurement error obtained when using a standard 5 ml discard volume. Comparable results were obtained from patients with various different types of CVC or portacath access.
The withdrawal of a 3 ml discard volume is sufficient to ensure that the subsequent blood sample is not diluted or contaminated by residual intra-luminal fluid. This may have a significant clinical impact in paediatric oncology, where patients frequently require blood transfusions due to the haematological toxicities associated with chemotherapy. It is hoped that these results will impact on hospital policies concerning specified discard volumes taken from CVCs prior to the withdrawal of blood samples for research purposes and routine clinical analysis.

  • [Show abstract] [Hide abstract]
    ABSTRACT: This study was designed to evaluate the clinical benefit of low-profile double-lumen port catheters in patients receiving simultaneous chemotherapy and parenteral nutrition (PN). Potential advantages, complications, and the durations of simultaneous and single use of the catheter were assessed. At a university teaching hospital, 10 patients received a double-lumen port catheter (5 men, 5 women; mean age 61.5 ± 12 years). All port implantations were performed under ultrasonographic and fluoroscopic guidance in the radiologic interventional suite. Procedure-related immediate, early, and late complications were recorded until removal of the device, patient's death, or completion of follow-up period. Application times and durations for chemotherapy or PN were determined. No immediate complications were observed. First use of the port system for chemotherapy was within 12 days (± 25 days, range 0-84 days) and within 17 hours (± 22 hours, range 0-72 hours) for PN on average. During the application of PN, no delay or interruption of chemotherapy was observed. The port catheter was used for the simultaneous application of chemotherapy and PN for a total of 1,216 hours. One port catheter was removed after 30 days due to suspected port infection. Central venous double-lumen port systems as a therapeutic option in patients requiring chemotherapy and PN can increase safety during those simultaneous applications, while offering improved patient comfort.
    The journal of vascular access 10/2010; 11(4):335-41. DOI:10.5301/JVA.2010.5812 · 1.02 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Lack of specific guidelines regarding collection of blood for culture from central venous catheters (CVCs) has led to inconsistencies in policies among hospitals. Currently, no specific professional or regulatory recommendations exist in relation to using, reinfusing, or discarding blood drawn from CVCs before drawing blood for a culture. Repeated wasting of blood may harm immunocompromised pediatric oncology patients. The purpose of this comparative study was to determine whether differences exist between blood cultures obtained from the first 5 mL of blood drawn from a CVC line when compared with the second 5 mL drawn. During 2009-2011, 62 pediatric oncology patients with CVCs and orders for blood cultures to determine potential sepsis were enrolled during ED visits. Trained study nurses aseptically drew blood and injected the normally discarded first 5 mL and the second specimen (usual care) into separate culture bottles. Specimens were processed in the microbiology laboratory per hospital policy. Positive cultures were evaluated to assess agreement between specimen results and to determine that the identified pathogen was not a contaminant. Out of 186 blood culture pairs, 4.8% demonstrated positive results. In all positive-positive matches, the normal discard specimen contained the same organism as the usual care specimen. In 4 matches, the normally discarded specimen demonstrated notably earlier time to positivity (4 to 31 hours) compared with the usual care specimen, which resulted in earlier initiation of definitive antibiotics. These findings support the accuracy of the specimen that is normally discarded and suggest the need to reconsider its use for blood culture testing.
    Journal of Emergency Nursing 06/2013; 40(4). DOI:10.1016/j.jen.2013.04.007 · 1.13 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction: Pharmacokinetic (PK) studies for long-established drugs are generally performed outside the well-standardized settings of pharmaceutical industry trials. Instead, such studies are usually performed within daily clinical practice of hospitals. Areas covered: This article describes aspects of intravenous (i.v.) drug administration and blood sampling that contribute to potential sources of preanalytical errors for PK investigations. Parameters that bias determination of start and end time of i.v. infusions, as well as consistent rate of drug delivery, are discussed. Causes for drug loss in the infusion device, including adsorption and insufficient flushing, are outlined. The advantages and disadvantages of different blood sampling techniques are reviewed, with an emphasis on pediatric studies. Expert opinion: For PK studies that are integrated into the general hospital routine, a variety of potential sources of error exist. Potential pitfalls depend on the specific drug and trial characteristics and they must be anticipated and discussed in advance. Working procedures need to be developed that address the anticipated problems and in detail describe procedures that need compliance between bed and bench.
    Expert Opinion on Drug Metabolism &amp Toxicology 04/2014; DOI:10.1517/17425255.2014.907273 · 2.93 Impact Factor