Full text
| |
| Author(s): |
Pedro Henrique Salles Brito
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Pirassununga. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT) |
| Defense date: | 2020-06-23 |
| Examining board members: |
Renata Gebara Sampaio Dória;
Claudia Barbosa Fernandes;
Raffaella Bertoni Cavalcanti Teixeira Santos;
Carlos Augusto Araújo Valadão
|
| Advisor: | Renata Gebara Sampaio Dória |
| Abstract | |
In veterinary medicine, several times, we need to perform surgical procedures on pregnant animals, whether elective or emergency. During general inhalation anesthesia in pregnant mares, there is a risk that maternal hemodynamic and hemogasometric changes may compromise uteroplacental perfusion and fetal oxygenation, increasing the risk of abortions or premature births. Generally, only emergencies and elective surgeries that do not puts at risk the fetus are performed, avoiding, as much as possible, general anesthesia in pregnant human or animals. In horses, cases such as acute abdomen, are often surgical emergencies, requiring general inhalation anesthesia in the pregnant mare, with all systemic changes from the disease involved. This study aimed to assess maternal and fetal changes during general inhalation anesthesia. Nine mares were anesthetized in the final third of gestation (> 300 days) and hemodynamic and hemogasometric parameters were analyzed over 90 minutes of general inhalation anesthesia with isoflurane at 1.5 minimum alveolar concentration (MAC) for the species, comparing simultaneously with fetal monitoring data, in order to check fetal distress throughout the anesthetic procedure. After anesthetic recovery, mares and fetuses were monitored daily and had all births monitored, with the APGAR score being performed to determine neonatal vitality. In addition, blood was collected from the newborn to assess blood count, hepatic and renal biochemical profile. Over time, a reduction in maternal blood pH was observed (T0 7.33 ± 0.08 - T75 7.24 ± 0.06, with values reduced in T60 and T75), arterial carbon dioxide pressure, showed values above the reference for the species in T30 (60.7 ± 6.26) and T60 (64.15 ± 5.07), the arterial oxygen pressure, rising only in T60 (FiO2 100% 149 ± 56.45 mmHg). Regarding fetal monitoring, a reduction in heart rate was observed from T30 (62.38 ± 7.05), which persisted throughout the anesthetic period (T75 60.75 ± 5.92), with recovery of values after anesthetic recovery (TPré 84.5 ± 12.07; Tpos after 78.11 ± 14.82), showing deleterious effects of anesthesia on fetal circulatory parameters. All mares had full term delivery and the foals received APGAR 8 score at birth, maximum rating for all foals. No hepatic and renal changes were observed in these neonates. It is concluded that, although anesthesia does not cause pregnancy losses or changes that influence the moment of delivery, trans-anesthetic maternal hemodynamic changes are evident and, consequently, fetal distress, evidenced by reduced heart rate. It is recommended to minimize as much as possible the period in which mares in the final third of gestation are kept in the dorsal recumbency and under the effect of anesthetic drugs that depress the cardiorespiratory system, in order to minimize the deleterious effects of maternal respiratory sistem and hemodynamic depression on the fetus. (AU) | |
| FAPESP's process: | 18/09347-7 - Fetal monitoring in pregnant mares submitted to inhalational anesthesia |
| Grantee: | Pedro Henrique Salles Brito |
| Support Opportunities: | Scholarships in Brazil - Master |