Assessment of anti-factor Xa activity of heparin in binary parenteral nutrition admixtures for premature neonates.

An in vitro study was carried out to determine the anti-Xa activity of heparin in binary parenteral nutrition (BPN) admixtures for premature neonates in our neonatal intensive care unit (NICU) after a 24-hour infusion, as well as to assess drug interaction with a 50% glucose solution. Two types of bags were prepared: (1) BPN admixtures (composition defined in the NICU) including sodium heparin at 77 UI/mL and (2) bags containing only G50% with sodium heparin at 193 UI/mL. The anti-Xa activity of heparin was measured in bags at T0, after the 24-hour infusion and in eluates at the outlet of the infusion line after 24hours, using a validated chromogenic anti-Xa method. Comparisons of the mean concentration observed with the theoretical value for anti-Xa activity were performed with the Student t-test. Mean values of anti-Xa activity do not differ significantly from the values expected for all conditions. We found a slight variation in anti-Xa activity when infused over 24hours for both types of bags, with and without in-line filtration, showing that heparin remains stable during this infusion period in both BPN admixtures and G50%.

Impact of infusion set characteristics on the accuracy of patient-controlled morphine administration: a controlled in-vitro study.

The aim of our in-vitro study was to assess the impact of infusion set characteristics on the accuracy of morphine doses in patient-controlled analgesia. Two infusion sets differing in conception and dead-space volume were assessed: a standard set and a low dead-space volume Y-set. The patient-controlled analgesia programme parameters were as follows: bolus equal to 1 ml at 100 ml.h(-1) ; lockout intervals equal to 5 and 10 min; and carrier fluid flow rate equal to 10 and 50 ml.h(-1) . Morphine concentration was determined by an ultraviolet spectrophotometric method. The morphine doses were significantly different from one set to the other during bolus and lockout intervals, whatever the patient-controlled analgesia programme. The average doses were approximately 1.3-6.0 times higher with the low dead-space volume Y-set during bolus. Our study underlines the impact of infusion set characteristics on the accuracy of morphine patient-controlled analgesia doses.

Prevention of drug delivery disturbances during continuous intravenous infusion: an in vitro study on a new multi-lumen infusion access device.

OBJECTIVE: Stopping and restarting carrier fluid flow and performing simultaneous drug infusions can lead to hazardous disturbances in drug delivery. The present study was designed to assess in vitro whether using a multi-lumen infusion access device could prevent noradrenaline disturbances. STUDY DESIGN: In vitro laboratory work. METHODS: Two infusion devices were studied: a standard device with a four-port manifold and a 150cm extension line and a nine-lumen infusion device (Edelvaiss-Multiline(®)) with eight accesses connected to nine separate lumens in a single tube of 150cm: seven accesses connected to seven peripheral lumens and one for the carrier fluid access connected to two lumens. Two experimental protocols of noradrenaline infusion were made: (a) drug flow rate change and (b) stop-and-go carrier fluid flows. Two parameters were studied: drug mass flow rate and flow change efficiency (FCE) calculated from the ratio of the area under the experimental mass flow rate curve to the area under the theoretical instantaneous mass flow rate curve. RESULTS: Variations in noradrenaline mass flow rate were more rapid with the Edelvaiss-Multiline(®) when the noradrenaline infusion rate was increased or decreased. FCE was significantly different from one infusion device to the other during both noradrenaline flow rate increase (standard vs. nine-lumen: 58% vs. 84%; P=0.008) and decrease (175% vs. 108%; P=0.008). Decreased drug delivery after stopping carrier fluid flow (standard vs. nine-lumen: 21% vs. 98%; P=0.008) and sudden temporary increases on resumption (253% vs. 103%; P=0.008) were reduced in magnitude and duration when using the Edelvaiss-Multiline(®) with a significant difference in FCE between the two infusion devices. CONCLUSIONS: Using the nine-lumen infusion device reduces drug delivery disturbances during continuous intravenous infusion.