Profiles From Tci Mode - Cardinal Health Alaris PK Directions For Use Manual

Syringe pump
Table of Contents

Advertisement

When targeting in TCI Mode the Alaris® PK Syringe Pump will automatically calculate the flow rate profile from the specific pharmacokinetic/
pharmacodynamic model for the selected drug. This section of the Directions For Use is intended to help users understand the profiled
infusion and the performance accuracy attained from the TCI pump.
Induction Bolus and maintenance rates are displayed before starting the titration. When initially starting the infusion or after increasing the
target (plasma or effect) concentration by titration, the pump will first deliver a bolus dose through a typically short, high rate infusion. On
completion of this bolus, the pump will immediately switch to a lower maintenance rate (when plasma target mode is used) or will pause
for a period of time before switching to a lower maintenance rate (when effect site targeting mode is used). Once the maintenance phase
is reached, any reduction made to the target (plasma or effect) concentration will typically result in the infusion rate reducing to zero until
the predicted plasma (or effect) concentration reduces the new target value.
The Alaris® PK Syringe Pump updates the pharmacokinetic model driving the plasma (or effect) concentration prediction and the infusion
rate every 10 seconds. The infusion rate graph, shown on page 38, were measured in accordance with the protocol described in the
1
IEC60601-2-24
Standard, with the data sample period reduced from 30 to 10 seconds.
The pump solves the pharmacokinetic/pharmacodynamic algorithms so that the target (plasma or effect) concentration is attained as
rapidly and as accurately as possible. However, the User may need to take into consideration the limitations of the physical system in
attaining the target (plasma or effect) concentration; this includes:
The limit on the flow rate permitted by the infusion pump mechanism;
The limit on the flow rate permitted by the syringe size;
The patient / drug dose limitation from the prescribing information to insure the safety of the administration;
The variation in individual patient response to reach the plasma (or effect) concentration;
The model specific cap rate.
A true assessment of the performance of the Alaris® PK Syringe Pump can be made if the volumetric error, that is the difference between
the actual volume infused and the predicted volume infused, is calculated. For the performance graphs shown on page 38, over a one hour
period, the Alaris® PK Syringe Pump has a mean volumetric accuracy in TCI Mode better than ±5%
By measuring the volume from the flow rate profile delivered from the Alaris® PK Syringe Pump and then introducing this into a reverse
pharmacokinetic model the predicted plasma (or effect) concentration can be calculated from the flow rate. These are illustrated on
page 39, showing the typical performance of the system against changes in the target plasma (or effect) concentration for a typical,
idealised profile. For the same targeted profile, the deviation of the predicted plasmatic (or effect) concentration (back calculated from the
volume collected) from the expected Ideal plasma (or effect) concentration, results from the volumetric inaccuracy of the system (pump
and syringe). The Alaris® PK Syringe Pump will track the predicted plasma (or effect) concentration to within ±5%
pharmacokinetic model over a one hour period. Flow rate inaccuracies and start-up delays may decrease the accuracy of the predicted
plasma (or effect) concentration particularly where high syringe drug concentrations are used in conjunction with large sizes of syringes
and low target plasma (or effect) concentrations as the syringe plunger motion over time (proportional to the flow rate accuracy) will be
significantly reduced.
A
For a given drug concentration, the volumetric error is proportional to the dose rate error. Knowledge of the
system accuracy over different time intervals may be of interest when assessing the impact of administering short-
half life drugs. In these circumstances, short-term fluctuation in the infusion rate could have a clinical impact that
cannot be determined from the performance profiles shown in Figures below. In general, the volumetric error
will increase with small induction and maintenance rates, which may occur when with large volume syringes, high
syringe concentrations, low patient weights and low target (plasma or effect) concentrations. For applications
where system accuracy is important, maintenance rates less than 1.0 ml/h are not recommended; syringe sizes,
drug concentrations / dilutions and target (plasma or effect) concentrations should be selected accordingly to
ensure the maintenance rate exceeds this lower limit.
The performance graphs illustrated in this section are for a Diprivan (1% Concentration); Diprivan (2% concentration), Remifentenil (50μg/
ml concentration), and Sufentanil (5μg/ml concentration) are given for comparison. As an illustration of the effect the syringe size has on
system performance, Remifentenil (50μg/ml concentration) is shown with a 50ml and 5ml syringe respectively.
The target (plasma or effect) concentrations shown are for illustrative purposes only
Note:
1
IEC60601-2-24: Particular Requirements for the Safety of Infusion Devices;
2
95% Confidence / 95% Population.

Profiles from TCI mode

1000DF00005 Iss. 2
2
.
37/44
2
of that calculated by

Advertisement

Table of Contents
loading

Table of Contents