V.I. Stamov, J.V. Deshko, A.A. Bunatian
Department of
Anaesthesiology, National Research Centre of Surgery, Moscow, Russia
Background and Goal of Study: We started using target controlled infusion
(TCI) by means of Diprifusor®
system (Fresenius Master TCI) in 1998. Now the infusion pumps came into
being which allow to conduct TCI-anaesthesia with 1% and 2% propofol as well as
that with sufentanil and remifentanil. The aim of our study was to define
functional potential of Asena® PK Syringe Pump for TCI & TIVA.
Patients and Methods:
With our institute ethical committee approval, the above mentioned perfusor was
put to the test during different abdominal operations of duration from 1 to 3
hrs. We studied 26 patients (8 male, 18
female) aged from 28 to 75 yrs (M + SD 52.2 + 11.2), ASA 1-3 (1.9
+ 0.6), weight ranged from 50 to 130 kg, BMI 19.5-51.1 kg/m2
(30.3 + 2.5). Premedication: i.m. diazepam (0.15-0.2 mg/kg) + chloropyramine
(0.4-0.6 mg/kg) + atropine (0.01-0.015 mg/kg). Preinduction: i.v. ondansetron
0.05-0.06 mg/kg + midazolam 0.03-0.06 mg/kg. Induction: 1% propofol (target 3.0
mcg/ml for 3 min), fentanyl 2-4 mcg/kg, cisatracurium 0.15 mg/kg, vecuronium
0,1 mg/kg or rocuronium 0.6 mg/kg. Maintenance: propofol (Ctarg
0.8-3.7 mcg/ml), fentanyl 4-8 mcg/ml/h, relaxants by bolus or infusion.
Monitoring: NIBP, HR, SpO2, etCO2, ECG,
acid-base balance, ARX-index (Alaris AEPTM Monitor), NMB (TOF-Watch®
SX, Organon). Statistical analysis: Student΄s t-test, Mann-Whitney U-test,
Spearmen correlation (SPSS 13.0).
Results and Discussion: The
patients fell asleep at Ceff of propofol 1.15 + 0.45 mcg/ml.
We did not allow Ceff to fall beyond the sleep concentration level,
and thus there were no cases of awareness. Anaesthesia duration was 145.7 +
46.4 min, time from the end of surgery to extubation – 15.9 + 7.4 min,
time from the end of propofol infusion to extubation – 10.8 + 5.5 min.
The awaking Ceff did not correspond to asleep Ceff in
most cases. Moreover, in 6 cases asleep Ceff was less than 30%
below, while in 4 cases it exceeded awaking Ceff by more than 40%.
However this is not the problem of the pump but that of individual
pharmacokinetic peculiarities (Marsh model). ARX-index provided the additional
information of depth of anaesthesia. Correlation between Ceff and
ARX-index during all anesthesia was -0.601 (p < 0.05) (757 pairs of
comparison).
|
Mean
+ SD |
Loss
of consciousness |
Awakening |
Correlation
|
|
Propofol C1, mcg/ml Ceff , mcg/ml ARX-index |
0.93
+ 0.35 mg/kg 1.84
+ 0.53 1.15
+ 0.45 30.8
+ 7.9 |
4.1
+ 1.3 mg/kg/h 0.87
+ 0.36 1.09
+ 0.41 68.1
+ 12.6 |
- 0.504
(p < 0.001) 0.614
(p < 0.001) 0.263
(p = 0.204) |
Perfusor
Asena® PK proved to be easy and comfortable to use. The monitor
displays vivid and full information about the parameters of infusion. Obvious
advantage: the possibility to use various types of syringes, the information on
the amount of drug sufficient at this infusion rate, drugs libraries. An additional
research has been made to estimate the possibilities of pump usage for the
conduction of the traditional infusion of propofol (in mg/kg/h account) and any
other drugs. Unlike the first perfusors with a built-in Diprifusor®
system this kind of pump is universal for different drugs. Also unique is that
during anaesthesia it is possible to shift from TCI-regime to traditional TIVA
and vice versa with Ctarg, C1, Ceff and
decrement time available on the pump display.
Conclusion: The
availability of the Asena® PK is undoubtedly an important step
forward in the development of TCI concept. The next step would be the
implementation of the already elaborated soft programmes to use infusion
propofol according to Schnider and Kataria models. This would enlarge the scope of TIVA
implementation even more.
References:
1 Schnider
T.W., Minto C.F., Gambus P.L. et al. Anesthesiology
1998; 88: 1170-1182.
2 Kataria
B.K., Ved S.A., Nicodemus H.F. et al. Anesthesiology
1994; 80: 104-122.