Towards more efficient use of intravenous lumens in multi-infusion settings: development and evaluation of a multiplex infusion scheduling algorithm

Abstract

Background: Multi-drug intravenous (IV) therapy is one of the most common medical procedures used in intensive care units (ICUs), operating rooms, oncology wards and many other hospital departments worldwide. As drugs or their solvents are frequently chemically incompatible, many solutions must be administered through separate lumens. When the number of available lumens is too low to facilitate the safe administration of these solutions, additional (peripheral) IV catheters are often required, causing physical discomfort and increasing the risk for catheter related complications. Our objective was to develop and evaluate an algorithm designed to reduce the number of intravenous lumens required in multi-infusion settings by multiplexing the administration of various parenteral drugs and solutions.

Methods: A multiplex algorithm was developed that schedules the alternating IV administration of multiple incompatible IV solutions through a single lumen, taking compatibility-related, pharmacokinetic and pharmacodynamic constraints of the relevant drugs into account. The conventional scheduling procedure executed by ICU nurses was used for comparison. The number of lumens required by the conventional procedure (L_CONV) and multiplex algorithm (L_MX) were compared.

Results: We used data from 175,993 ICU drug combinations, with 2251 unique combinations received by 2715 consecutive ICU patients. The mean ± SD number of simultaneous IV solutions was 2.8 ± 1.6. In 27% of all drug combinations, and 61% of the unique combinations the multiplex algorithm required fewer lumens (p < 0.001). With increasing L_CONV, the reduction in number of lumens by the multiplex algorithm further increased (p < 0.001). In only 1% of cases multiplexing required > 3 lm, versus 12% using the conventional procedure.

Conclusion: The multiplex algorithm addresses a major issue that occurs in ICUs, operating rooms, oncology wards, and many other hospital departments where several incompatible drugs are infused through a restricted number of lumens. The multiplex algorithm allows for more efficient use of IV lumens compared to the conventional multi-infusion strategy.

Keywords: Algorithms; Drug incompatibility; Infusion pumps; Infusions, intravenous; Injection site reaction.

Fig. 1

Multiplexed fluid administration through an IV tube. Using multiplex infusion packets of intravenous solutions a, b, and c are administered through a single IV tube, where solution S serves as separator. All drugs within a packet are compatible with each other

Fig. 2

Conventional scheduling procedure and the multiplex scheduling algorithm. Using the conventional scheduling procedure drugs are initially divided lumens based on drug category and subsequently based on compatibility (Panel a). The multiplex algorithm (Panel b) has to satisfy utility and maximal administration rate (Q_MAX) related constraints for successful scheduling. When a drug cannot be multiplexed, it will be scheduled following the conventional scheduling procedure.

Fig. 3

Earliest deadline first (EDF) scheduling. The end of every period P_I is a deadline for the administration of the respective packet. A separator packet A separator fluid volume (SFV) is considered as part of each packet during scheduling. The deadline is related to the PK/PD characteristics of the drug or solution so that sufficiently stable sustained biological action of the constituent(s) is maintained under repeated interrupted administration. Here the so called utility, or U-value is U_A + U_B + U_C = 5/20 + 5/30 + 10/20 = 11/12. AS U ≤ 1, Scheduling is feasible. Packet A, that has the nearest deadline, is scheduled first, followed by packets C and B until all Packets are scheduled. The Hyperperiod, or least common mutiple of the periods, is 60 minutes in the example.

Fig. 4

Lumens and separator fluid volumes required by the multiplex algorithm for the different values of D_drugs. Panel a shows lumens and separator fluid volumes for all levels of L_CONV assuming a Vygon V-Green IV tube (Vygon, France; 2 m, 2 mL). Panel b shows the same data, however schedules where L_CONV was equal to 1 were omitted as this number could obviously not be reduced to zero by multiplexing. In both panels the dashed orange line indicates the mean of L_CONV and the dashed blue line indicates the mean hourly volume of volumetric saline and glucose infusions

Fig. 5

Number of IV lumens required by conventional scheduling (L_CONV) and multiplex scheduling (L_MX). Values of L_CONV and L_MX as determined over 1 h periods (panels a and b) and the maximal values of L_CONV and L_MX aggregated over 24 h periods from midnight to midnight (panels c and d). Note that D_drugs = 5 min in panels b and d