PURPOSE: The peripherally inserted central catheter (PICC) is used in hospitalized patients to obtain blood samples, minimizing patient discomfort from venipunctures. Because heparinized saline within the PICC lumen may affect the activated partial thromboplastin time (aPTT), patients who require aPTT monitoring have frequent venipunctures. We tested the hypothesis that plasma aPTT values obtained through a PICC would not be clinically different to aPTT values obtained from venipuncture.
METHODS: 25 patients with a PICC already inserted were enrolled from the inpatient service of a university hospital. Baseline demographics were obtained on all study patients. Once patients had given consent, two blood samples, one from the PICC and one from a peripheral venipuncture, were drawn simultaneously. Blood was drawn from the PICC according to a standardized procedure, which included a discard volume of 5cc. All samples were drawn by one team member for standardization and immediately transported on ice to the laboratory. The technician who performed the aPTT analyses was blinded to the method of procurement (venipuncture or PICC).
RESULTS: Samples from 25 patients were collected. Average age was 40±15 years; 60% were male. The mean duration that PICCs had been indwelling at the time of sample collection was 40.3±15.5 hours. The median aPTT value from the PICC and venipuncture was 35 seconds and 32.3 seconds, respectively. In only one sample was there a clinical difference between aPTT values obtained through the PICC compared to those obtained through venipuncture.
CONCLUSION: Using plasma obtained from a PICC to monitor the aPTT results in values that do not differ clinically from values obtained through peripheral venipunctures.
CLINICAL IMPLICATIONS: Adherence to a standardized protocol to monitor aPTT using indwelling PICCs minimize patient discomfort while allowing for the accurate assessment of the aPTT.
DISCLOSURE: Matthew Rondina, None.