Obstetric Anaesthesiology
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Mini-dose of oxytocin at the beginning of spinal anaesthesia for Caesarean section: the influence on uteroplacental blood flow
Anaesthetic techniques, subarachnoid, Fetus
V. Fesenko1, L. Nazarenko2, O. Kozmuk3, O. Nastenko3, P. Torroni4
1Danylo Yalytsky Lviv National Medical University - Lviv (Ukraine), 2Kharkiv Medical Academy for Postgraduate Education - Kharkiv (Ukraine), 3Kharkiv City Clinical Maternity Hospital #6 - Kharkiv (Ukraine), 4Civitanova Marche Community Hospital - Civitanova Marche (Italy)
Background and Goal of Study: Our previous results [1] showed that in spinal anaesthesia (SA) for Caesarean section (CS), Torroni’s technique of i.v. administration of 0.5 IU of oxytocin immediately after SA and before delivery significantly attenuated maternal arterial hypotension and lessened phenylephrine use.
The goal of our study was to assess the possible influence of this technique on the uteroplacental blood flow.
Materials and Methods: SA for elective CS was performed in 12 women, randomly divided into study (n=6) and control (n=6) groups. In the study group, slow i.v. bolus of oxytocin (0.5 IU) was administered immediately after SA performance. Uterine and umbilical circulation blood flow was measured just before and 5-6 min after performance of SA.
Results and Discussion: Right uterine artery systolic/diastolic ratio (SDR) in the study and control groups (M±SD) was, resp., 1.69±0.09 and 2.07±0.68 before, 3.49±1.80 and 3.09±1.26 after SA performance, all differences insignificant; resistance index (RI) was, resp., 0.40±0.03 and 0.51±0.12 before, 0.65±0.10
(p=0.004 vs pre-anaesthetic) and 0.56±0.14 after SA performance. Left uterine SDR was, resp., 1.75±0.21 and 2.07±0.61 before, 3.77±1.83 (p=0.041 vs pre-anaesthetic) and 3.38±0.95 (p=0.035 vs pre-anaesthetic) after SA performance; RI was, resp., 0.42±0.06 and 0.49±0.10 before, 0.68±0.11 (p=0.003 vs preanaesthetic) and 0.67±0.09 (p=0.018 vs pre-anaesthetic) after SA performance. Umbilical arterial SDR was, resp., 2.49±0.26 and 2.59±0.31 before, 2.92±0.93 and 2.72±0.87 after SA performance; RI was, resp., 0.59±0.05 and 0.58±0.06 before, 0.62±0.13 and 0.59±0.11 after SA performance. Any intergroup difference was not significant. The moderately increased resistance of uterine arteries during SA in both groups may result from both regional analgesia and uterine contractions. Umbilical arterial RI did not change significantly.
Conclusion(s): Torroni’s technique during spinal anaesthesia for Caesarean section has no negative influence on uteroplacental blood flow.
References (optional): 1. Fesenko V, Nastenko O, Torroni P. Mini-dose of oxytocin at the beginning of spinal anaesthesia for Caesarean section: the influence on maternal circulation. Anestezjologia Intensywna Terapia (Poland) 2017; 49 (Suppl. 2): 23.


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