Efeitos do modo ventilatório sobre as variáveis hemogasométricas em equinos submetidos à mudança de decúbito durante a anestesia geral inalatória com halotano
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Data
2008-09-12
Autores
Sá, Paula Aguiar [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Em eqüinos, mudanças de decúbito durante anestesias prolongadas podem contribuir para a redução da oxigenação sanguínea; uma vez que o lobo pulmonar não dependente (funcional) é repentinamente comprimido. Hipotetizou-se que a mudança de decúbito durante a anestesia reduziria significativamente a oxigenação sanguínea (PaO2) e que a instituição da ventilação controlada seria capaz de prevenir a diminuição da PaO2 após a mudança de decúbito. Foram utilizados 16 eqüinos adultos hígidos, sem raça definida, com peso corpóreo de 444,3 ± 42,5 Kg, provenientes do Regimento de Cavalaria “Dragões da Independência”. Os animais foram submetidos a procedimentos cirúrgicos onde fosse necessária a mudança de decúbito. Mediante jejum alimentar de 12 horas e hídrico de 4 horas, os animais foram premedicados com acepromazina (0,05 mg/kg, IM) e após 30 minutos, com xilazina (0,5 mg/kg, IV). A anestesia foi induzida com diazepam (0,1 mg/kg, IV) e cetamina (2,2 mg/kg, IV) e mantida com halotano diluído em O2. A dobutamina foi empregada para manter a pressão arterial média acima de 70 mm Hg durante todo o procedimento. Os animais foram equitativamente divididos em 2 grupos, sendo que no grupo VE a anestesia foi mantida sob ventilação espontânea, enquanto no grupo VC a anestesia foi mantida sob ventilação controlada (frequência respiratória: 6 mov/min, relação inspiração/expiração: 1/3, volume corrente: 15 mL/kg e pressão de pico inspiratório entre 25 a 30 cm H2O). Os procedimentos cirúrgicos foram iniciados em decúbito lateral esquerdo (DLE) e, após 75 minutos, os animais foram reposicionados em decúbito lateral direito (DLD) até o término da cirurgia. Análises hemogasométricas do sangue arterial foram realizadas após 30 e 75 minutos de posicionamento em cada decúbito (M1 e M2 no DLE e M3 e M4 no DLD, respectivamente). Durante a VE, observou-se...
In horses, changes in body position during anesthesia may contribute to a reduction in arterial oxygenation because the non-dependent lung (functional) is suddenly compressed. It was hypothesized that the change in recumbency during anesthesia would significantly reduce the arterial oxygenation (PaO2) and the institution of controlled ventilation would prevent the descrease in PaO2 after the change in body position. A total of 16 healthy adult mixed breed horses horses of the Cavalry Regiment “Dragões da Independência”, weighting 444,3 ± 42,5 Kg, were used. All animals underwent procedures in which a change in body position would be necessary to perform surgery. Food and water were withheld for 12 and 4 hours respectively. All animals received acepromazine (0.05 mg/kg, IM), followed 30 minutes later by xylazine (0.5 mg/kg, IV). Anesthesia was induced with diazepam (0.1 mg/kg, IV) and ketamine (2.2 mg/kg, IV) and maintained with halothane in oxygen. Dobutamine was used to maintain mean arterial blood pressure above 70 mmHg throughout the procedure. The animals were equally divided into 2 groups: in the SV group anesthesia was maintaned under spontaneous ventilation whereas in the CV group anesthesia was maintained under controlled ventilation (respiratory rate: 6 breaths/min, inspiration-to-expiration ratio: 1/3, tidal volume: 15 ml/kg, and peak inspiratory pressure between 20 and 30 cmH2O). All surgical procedures were commenced in left lateral recumbency (LLR) and 75 minutes later the animals were repositioned in right lateral recumbency (RLR). Arterial blood gas analysis was performed at 30 and 75 minutes after the animals were placed in left recumbency (M1 and M2, respectively), and at 30 and 75 minutes after the animals were repositioned in right lateral recumbency (M3 and M4, respectively). Hypercapnia (PaCO2 > 45 mm Hg) and respiratory acidosis (pH < 7.35)... (Complete abstract click electronic access below)
In horses, changes in body position during anesthesia may contribute to a reduction in arterial oxygenation because the non-dependent lung (functional) is suddenly compressed. It was hypothesized that the change in recumbency during anesthesia would significantly reduce the arterial oxygenation (PaO2) and the institution of controlled ventilation would prevent the descrease in PaO2 after the change in body position. A total of 16 healthy adult mixed breed horses horses of the Cavalry Regiment “Dragões da Independência”, weighting 444,3 ± 42,5 Kg, were used. All animals underwent procedures in which a change in body position would be necessary to perform surgery. Food and water were withheld for 12 and 4 hours respectively. All animals received acepromazine (0.05 mg/kg, IM), followed 30 minutes later by xylazine (0.5 mg/kg, IV). Anesthesia was induced with diazepam (0.1 mg/kg, IV) and ketamine (2.2 mg/kg, IV) and maintained with halothane in oxygen. Dobutamine was used to maintain mean arterial blood pressure above 70 mmHg throughout the procedure. The animals were equally divided into 2 groups: in the SV group anesthesia was maintaned under spontaneous ventilation whereas in the CV group anesthesia was maintained under controlled ventilation (respiratory rate: 6 breaths/min, inspiration-to-expiration ratio: 1/3, tidal volume: 15 ml/kg, and peak inspiratory pressure between 20 and 30 cmH2O). All surgical procedures were commenced in left lateral recumbency (LLR) and 75 minutes later the animals were repositioned in right lateral recumbency (RLR). Arterial blood gas analysis was performed at 30 and 75 minutes after the animals were placed in left recumbency (M1 and M2, respectively), and at 30 and 75 minutes after the animals were repositioned in right lateral recumbency (M3 and M4, respectively). Hypercapnia (PaCO2 > 45 mm Hg) and respiratory acidosis (pH < 7.35)... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Equino - Cirurgia, Anestesia - Efeitos fisiológicos, Horse, Inhalation anesthesia, Recumbency
Como citar
SÁ, Paula Aguiar. Efeitos do modo ventilatório sobre as variáveis hemogasométricas em equinos submetidos à mudança de decúbito durante a anestesia geral inalatória com halotano. 2008. 65 f. Dissertacão (mestrado) - Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, 2008.