Evaluation of the FASTSTART mode for reducing start-up delay in syringe pump infusion systems

Types and Frequency of Infusion Pump Alarms and Infusion-Interruption to Infusion-Recovery Times for Critical Short Half-Life Infusions: Retrospective Data Analysis

BACKGROUND

Alarm fatigue commonly leads to a reduced response to alarms. Appropriate and timely response to intravenous pump alarms is crucial to infusion continuity. The difficulty of filtering out critical short half-life infusion alarms from nonurgent alarms is a key challenge for risk management for clinicians. Critical care areas provide ample opportunities for intravenous medication error with the frequent administration of high-alert, critical short half-life infusions that require rigorous maintenance for continuity of delivery. Most serious medication errors in critical care occur during the execution of treatment, with performance-level failures outweighing rule-based or knowledge-based mistakes.

OBJECTIVE

One objective of this study was to establish baseline data for the types and frequency of alarms that critical care clinicians are exposed to from a variety of infusion devices, including both large volume pumps and syringe drivers. Another objective was to identify the volume of these alarms that specifically relate to critical short half-life infusions and to evaluate user response times to alarms from infusion devices delivering these particular infusions.

METHODS

The event logs of 1183 infusion pumps used in critical care environments and in general care areas within the European region were mined for a range of alarm states. The study then focused on a selection of infusion alarms from devices delivering critical short half-life infusions that would warrant rapid attention from clinicians in order to avoid potentially harmful prolonged infusion interruption. The reaction time of clinicians to infusion-interruption states and alarms for the selected critical short half-life infusions was then calculated.

RESULTS

Initial analysis showed a mean average of 4.50 alarms per infusion in the general critical care pump population as opposed to the whole hospital rate of 1.39. In the pediatric intensive care unit (PICU) group, the alarms per infusion value was significantly above the mean average for all critical care areas, with 8.61 alarms per infusion. Infusion-interruption of critical short half-life infusions was found to be a significant problem in all areas of the general critical care pump population, with a significant number of downstream (ie, vein and access) occlusion events noted. While the mean and median response times to critical short half-life infusion interruptions were generally within the half-lives of the selected medications, there was a high prevalence of outliers in terms of reaction times for all the critical short half-life infusions studied.

CONCLUSIONS

This study gives an indication of what might be expected in critical care environments in terms of the volume of general infusion alarms and critical short half-life infusion alarms, as well as for clinician reaction times to critical short half-life infusion-interruption events. This study also identifies potentially problematic areas of the hospital for alarm fatigue and for particular issues of infusion and infusion-line management. Application of the proposed protocols can help create benchmarks for pump alarm management and clinician reaction times. These protocols can be applied to studies on the impact of alarm fatigue and for the evaluation of protocols, infusion-monitoring strategies, and infusion pump-based medication safety software aimed at reducing alarm fatigue and ensuring the maintenance of critical short half-life infusions. Given the frequency of infusion alarms seen in this study, the risk of alarm fatigue due to the white noise of pump alarms present in critical care, to which clinicians are constantly exposed, is very high. Furthermore, the added difficulties of maintaining critical short half-life infusions, and other infusions in specialist areas, are made clear by the high ratio of downstream occlusion to infusion starts in the neonatal intensive care unit (NICU). The ability to quantitatively track the volume of alarms and clinician reaction times contributes to a greater understanding of the issues of alarm fatigue in intensive care units. This can be applied to clinical audit, can allow for targeted training to reduce nuisance alarms, and can aid in planning for improvement in the key area of maintenance of steady-state plasma levels of critical short half-life infusions. One clear conclusion is that the medication administration rights should be extended to include right maintenance and ensured delivery continuity of critical short half-life infusions.

Impact of priming the infusion system on the performance of target-controlled infusion of remifentanil

BACKGROUND

The start-up behavior of syringe and syringe pump is known to be one of the causes of inaccurate intravenous infusion. This study evaluated the method of priming the infusion system (PRIMING), and its impact on the target-controlled infusion (TCI) of two remifentanil diluents.

METHODS

PRIMING was performed using an evacuation of 2.0 ml to the atmosphere prior to TCI. Forty-eight TCI, using 50 µg/ml (Remi50) or 20 µg/ml (Remi20) of diluents, were performed targeting 4.0 ng/ml of effect-site concentration (Ceff), with PRIMING or not. The gravimetrical measurements of the delivered infusates reproduced actual Ceff. The bolus amount and time to reach 95% target were compared.

RESULTS

Without PRIMING, Remi50 infused less bolus (43 ± 23 %) than Remi20 (19 ± 9 %) (P = 0.003), and showed more delayed increase of Ceff (11.2 ± 4.0 min) than Remi20 (7.4 ± 0.4 min) (P = 0.028). However, PRIMING significantly decreased the deficit of the bolus (2 ± 1%), as well as the delay of the increase of Ceff in Remi50 (1.2 ± 0.2 min) (both P < 0.001). In addition, with PRIMING, the start-up bolus showed minimal difference to the nominal bolus (1 and 2%), and Ceff were increased to 4.0 ± 0.1 ng/ml at the expected time of peak effect, irrespective of the diluents.

CONCLUSIONS

Proper operation of the syringe pump used in the priming of the syringe may be helpful in reduction of the inaccuracy of TCI, particularly during the early phase of infusion, or the infusion of a more concentrated diluent.

False selection of syringe-brand compatibility and the method of correction during target-controlled infusion of propofol

Background

We evaluated volumetric differences of syringe brand compatibilities, and investigated the impact of false brand settings on target-controlled infusion (TCI) and their methods of correction.

Methods

Gravimetric measurement of 10 ml bolus infusions was performed using BD Plastipak (BDP) and Terumo compatible syringes, while setting to 7 different kinds of brand compatibilities (BDP, Sherwood Monoject, BD Perfusion, Braun Perfusor, Braun Omnifix, Fresenius Injectomat, and Terumo). To investigate the performance of TCI using BDP with a false setting to Terumo (BDP_TERUMO) and Terumo to BDP (TERUMO_BDP), 24 TCI targeting 4.0 µg/ml of effect-site concentration (C_eff) of propofol were performed. Subsequently, another 24 TCI were evaluated for simple corrections of false settings at 30 min. We also investigated 24 TCI using active corrections (fill-up for BDP_TERUMO, evacuation for TERUMO_BDP) based on the pharmacokinetics of propofol. The C_eff at 30 min of TCI and time to normalize to ± 5% of target concentration (T_±5%target) were compared.

Results

The C_eff of BDP_TERUMO showed negative bias and 17.2% inaccuracy, and the C_eff of TERUMO_BDP showed positive bias and 19.5% inaccuracy. The C_eff at 30 min showed no difference between the methods of correction in BDP_TERUMO or TERUMO_BDP. The T_±5%target in both the active corrections was significantly shorter than that of each simple corrections (P < 0.001).

Conclusions

False brand setting of syringe proportionally maintained different predicted concentrations as much as the volumetric differences of syringe brand. Based on the results, it is proposed that correction methods based on pharmacokinetics could effectively normalize the differences, without giving up the wrong TCI.

In-line filter included into the syringe infusion pump assembly reduces flow irregularities

PURPOSE

To evaluate whether an in-line filter inserted in the syringe pump infusion line assembly influences start-up times and flow irregularities during vertical pump displacement at low infusion rates.

METHODS

Fluid delivery after syringe pump start-up and after vertical displacement of the syringe pump by -50 cm was determined gravimetrically at flow rates of 0.5, 1.0 and 2.0 ml h(-1). Measurements were repeated for each flow rate four times with two different syringe pumps with and without an in-line filter incorporated. Data are shown as median and range.

RESULTS

Start-up times were reduced by an in-line filter at 0.5 ml h(-1) flow rate from 355.5 s (0-660) to 115 s (0-320), whereas the effect was attenuated at higher flow rates. Pooling of fluid into the infusion system after lowering the infusion syringe pump was halved in all flow rates tested. Amount of infusion bolus after elevating the syringe pump by 50 cm was not affected by an in-line filter.

CONCLUSION

In the evaluated model in-line filters help to reduce flow irregularities and delay in drug delivery of syringe pumps at low flow rates and represent an option to optimize continuous administration of highly concentrated short-acting drugs at very small infusion rates.