PR215VARIABILITY OF ENTROPY AS AN INDICATOR FOR STABILITY OF ANAESTHESIA DEPTH

DURING IN VITRO FERTILIZATION PROCEDURES

I. V. Potievskaya, I. L. Ushakov

Russian Medical Academy for Postgraduate Training

Clinical Hospital “Moscvorechye’, Russia

Introduction. It has been shown that entropy

monitoring allows to assess depth of anaesthesia and

improves anaesthesia awareness [1, 2]. Usually

response entropy (RE) and state entropy (SE) are

measured. We suggested a new calculated parameter

- variability of entropy (VE) to evaluate stability of

anaesthesia. The objective of the study was to

compare stability of intravenous propofol and volatile

sevoflurane anaesthesia during oocytes retrieval by VE

assessment.

Results. There was no significant difference between

sevoflurane and propofol groups in duration of different periods

of anaesthesia (table). In all patients RE and SE values were

below 60 that reflected adequate depth of anaesthesia and did

not significantly differ between groups during induction period

(p=0.52 for RE and p=0.54 for SE) and awakening period

(p=0.18 for RE and p=0.24 for SE (fig.1, 2). At the moment of

oocytes retrieval RE and SE were lower in group 1 comparing

with group 2 (21 [7; 29] vs 36 [10; 56]; p< 0.05 for RE and 20

[7; 27] vs 30 [8; 45]; p< 0.05 for SE). VE was higher in the

group of propofol comparing with sevoflurane during periods of

induction and oocyte retrieval (p<0.05), (fig. 3). This fact may

reflect more stable level of anaesthesia depth in the group of

sevoflurane.

Conclusion. Assessment of variability of entropy in addition to

RE and SE allows not only detect the depth of anaesthesia,

but also more clearly evaluate its stability and balance of

hypnotic and analgesic effects. Use of volatile anaesthetic

sevoflurane during oocytes retrieval demonstrated more stable

anaesthesia level than propofol.

variables

group

Induction

time, s

X±m

Oocytes

retrieval

time, s,

X±m

Total

anesthesia

time, s

X±m

Awakening

time, s

X±m

А (sevoflurane) n=13 125±5 224±33 348±32 395±33

B (propofol) n=13 93±11 353±85 447±87 353±44

Methods. Design: prospective monocentric pilot study. 26

women of ASA physical status I scheduled for oocytes

retrieval were randomized into two groups. In group 1

induction of anaesthesia was performed with sevoflurane.

In group 2 patients received intravenous intermittent

propofol boluses.

VE = RE - SE/SE×100%

Data were presented as mediana, Mann-Whitney test was

applied.

Table. Comparative duration of different anaesthesia

periods in sevoflurane and propofol groups.

1. Bein B. "Entropy". Best practice&research clinical anesthesiology 2006, 20 (1): 101-109.

2. 2. Gao JD, Zhao YJ, Xu CS, Zhao J et al. "Evaluation of entropy for monitoring the depth of anesthesia compared with bispectral index: a multicenter clinical trial". Chin Med J (Engl), 2012,

125 (8): 1389–92.

0,0

50,0

100,0

150,0

1 2 3 4 5

Mean RE at different periods of

anaesthesia

группа 1

группа 2

Group1

Group2

0,0

20,0

40,0

60,0

80,0

100,0

1 2 3 4 5

Mean SE at different periods of

anaesthesia

группа 1

группа 2

Group1

Group2