(S-217) Komatsu, T., Monday 9:15
TITLE: REAL TIME MONITORING OF FOUR-BEATS ENTROPY OF HEART RATE VARIABILITY DURING RAPID INHALATION INDUCTION IN CHILDREN: SEVOFLURANE VS. HALOTHANE
AUTHORS: Toru Komatsu, MD1, Hiroshi Noguchi, MD1, Tomomasa Kimura, MD2, Kimitoshi Nishiwaki, MD2
AFFILIATION: 1Aichi Medical University, Nagakutecho, Aichi, Japan; 2Nagoya University, Nagoya, Japan.
The four-beats entropy (4RR.ENT) of heart rate variability (HRV) can be assessed by the linearized version of the nonlinear least squares method combined with the maximum entropy spectral analysis method(MemCalc)(1). This study examined 4RR.ENT of HRV by MemCalc as an indicator of the hemodynamic control during rapid induction of 3% halothane and 5% sevoflurane anesthesia.
METHODS: Thirty two pediatric patients (ASA PS I) under- going eye surgery were studied: Group 1 (3% halothane, n=16). Group 2 (5% sevoflurane, n=16). All patients were allowed to breath spontaneously through mask for 10 min, and then ventilated manually for 5 min. RR intervals of ECG were measured throughout the period of the study. 4RR.Ent was calculated on every 4 RR intervals and normalized by the lowest theoretical entropy and the highest theoretical entropy by MemCalc (Suwa Trust, Tokyo). The responses of time- dependent changes of 4RR.ENT and spectral components were evaluated. Statistical analysis was performed by a repeated measured ANOVA.
RESULTS: 4RR.ENT was preserved during spontaneous breathing during induction of anesthesia in both Groups and decreased after the initiation of the manual ventilation. Spectral components of RR intervals decreased on the time-dependent manner.
DISCUSSION: 4RR.ENT, and spectral components of RR intervals obtained by MemCalc method revealed different time- dependent changes of hemodynamic control during rapid induction of anesthesia with 3% halothane and 5% sevoflurane. During spontaneous breathing, 4RR.ENT was preserved and Spectral components of HRV decreased on the time-dependent manner, indicating the control of the hemodynamics was not deteriorated even ANS activity decreased. Real time monitoring of 4RR.ENT is useful to assess the hemodynamic control.
REFERENCE:
1) Am. J. Physiol 275:797, 1998.
Table 1. Changes in Heart rate (HR) and four beats Entropy of Heart Rate Variability
|
|
5% Sevoflurane |
3% Halothane |
||
|
min |
HR(bpm) |
Entropy(%) |
HR(bpm) |
Entropy(%) |
|
0 |
92(8) |
55(8) |
98(18) |
52(13) |
|
1 |
98(14) |
56(9) |
116(23) |
43(15) |
|
2 |
103(22)* |
49(14) |
106(19) |
41(6) |
|
3 |
101(32) |
49(18) |
106(19)* |
45(8) |
|
4 |
90(23) |
42(22) |
103(20) |
49(9) |
|
5 |
87(16) |
47(15) |
96(15) |
51(7) |
|
6 |
83(14) |
47(15) |
91(12) |
47(8) |
|
7 |
84(16) |
45(13) |
89(11) |
47(10) |
|
8 |
89(15) |
46(11) |
86(10)* |
50(11) |
|
9 |
88(16) |
44(13) |
85(10)* |
49(8) |
|
10 |
89(15) |
42(15) |
86(11)* |
42(8) |
|
11 |
92(15) |
38(19) |
90(14) |
43(12) |
|
12 |
96(16) |
27(16)* |
92(15) |
33(18)* |
|
13 |
99(16) |
19(13)* |
93(16) |
32(16)* |
|
14 |
101(17) |
14(12)* |
94(17) |
26(17)* |
|
15 |
102(17) |
14(10)* |
94(17) |
27(19)* |
n=16, Mean(SD), *p<0.05 vs. 0 min, 0 min: Awake, 1-10min: Spontaneous respiration, 11-15 min: Control Ventilation.