Antireflux valves in patient-controlled analgesia

Criteria for choosing an intravenous infusion line intended for multidrug infusion in anaesthesia and intensive care units

OBJECTIVE

The aims are to identify critical parameters influencing the drug mass flow rate of infusion delivery to patients during multidrug infusion and to discuss their clinical relevance.

DATA SOURCES

A review of literature was conducted in January 2016 using Medline, Google Scholar, ScienceDirect, Web of Science and Scopus online databases.

DATA EXTRACTION

References relating to the accuracy of fluid delivery via gravity-flow intravenous (IV) infusion systems and positive displacement pumps, components of IV administration sets, causes of flow rate variability, potential complications due to flow rate variability, IV therapies especially at low flow rates and drug compatibilities were considered relevant.

DATA SYNTHESIS

Several parameters impact the delivery of drugs and fluids by IV infusion. Among them are the components of infusion systems that particularly influence the flow rate of medications and fluids being delivered. By their conception, they may generate significant start-up delays and flow rate variability. Performing multidrug infusion requires taking into account two main points: the common dead volume of drugs delivered simultaneously with potential consequences on the accuracy and amount of drug delivery and the prevention of drug incompatibilities and their clinical effects.

CONCLUSION

To prevent the potentially serious effects of flow rate variability on patients, clinicians should receive instruction on the fluid dynamics of an IV administration set and so be able to take steps to minimise flow rate changes during IV therapy.

[Benefit-risk and monitoring modalities of different techniques and methods of postoperative analgesia]

This review aimed to determine the benefits-risks ratio of postoperative analgesia. The various agents usually used for intravenous postoperative analgesia (paracetamol, NSAID's, opioids), and the techniques for postoperative analgesia (PCA, epidural, perinervous block) are analysed. The rules proposed for the monitoring of postoperative analgesia are considered.

[Analgesia controlled by the patient in pediatrics]

The development of patient controlled analgesia (PCA) in children is the result of a search for an analgesia being both maximally efficient and secure, in the management of severe pain. The technique is based on self infusions of an analgesic, mainly morphine, by the child, through a special pump. The quality of the pump is essential in order to exclude any risk of overdosage. In order to prevent potential secondary effects and complications, a careful supervision is mandatory (clinical, by pulse oximetry, regular checking of pump parameters). PCA is applicable to children older than 5 years. The main indications are post-operative and oncological pains.

Antireflux valves in intravenous opioid analgesia: are they necessary?

A study was conducted in patients receiving intravenous opioid analgesia to determine the incidence and degree of retrograde flow along the parallel gravity-driven infusion line. From 1187 hours of observations retrograde flow was found in 2.5% of the total time. In 70% of these cases this was equivalent to less than 1 mg of pethidine and in 96% this was equivalent to less than 5 mg of pethidine. The need for routine use of antireflux valves during intravenous opioid analgesia is therefore questioned.

Patient-controlled analgesia: can it be made safer?

Patient-controlled analgesia (PCA) has been shown to provide superior pain relief when compared with standard therapy options for postoperative analgesia. If PCA is to be implemented widely in teaching, private and country hospitals, its effectiveness needs balanced with a high safety profile. This can be achieved by consideration of patient selection, comprehensive education of patients, medical and nursing staff and equipment familiarisation. Continuous clinical audit allows identification of problem areas along with monitoring analgesic efficacy.