Efeitos cardiorrespiratórios e hemogasométricos da ventilação controlada com pressão positiva expiratória final associada ao pneumoperitônio com dióxido de carbono em coelhos

• Autor(a) principal: Augusto, Luís Eugênio Franklin
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5143
• topic: Pneumoperitônio; PEEP; Hemogasometria; Pneumoperitôneum; PEEP; Hemogasometry; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA

Pneumoperitoneum using carbon dioxide (CO2) is used for better visualization of surgical field during laparoscopic surgeries and it has been associated to hemodynamic, respiratory and metabolic changes. The major complications are intraabdominal pressure increasing (IAP) and CO2 absorption. To maintain the appropriate respiratory function can be used positive end-expiratory pressure (PEEP). This study evaluate if ventilation controlled with 0, 5 and 10 cmH2O PEEP minimize changes promoted by pneumoperitoneum with 15 cmH2O IAP in cardiovascular and respiratory functions and arterial gasometry on the pulmonary parenchyma in rabbits anesthetized with isoflurane. Thirty-six rabbits were randomly divided into three groups according to PEEP level: GZP (0 cmH2O), G5P (5 cmH2O) and G10P (10 cmH2O). The variables partial oxygen pressure in arterial blood [pO2(a)], partial carbon dioxide pressure in arterial blood [pCO2(a)], arterial blood pH [pH(a)], plasma bicarbonate concentration in arterial blood [cHCO3 -(a)], base concentration in arterial blood [cBase(a)], K+ (cK+), Ca2+(cCa+2), Na+ (cNa+) and Cl- (cCl-) concentrations, GAP, partial carbon dioxide pressure in end expiratory (EtCO2), heart rate (HR), diastolic blood pressure (DBP), systolic blood pressure (SBP), mean arterial blood pressure (MAP) and temperature were evaluated at different times of anesthesia. The animals were euthanized at the following times: 0, 6, 12 and 24 hours after anesthesia. During autopsy, the lung lobes fragments were collected to do histological slides for histological evaluation of: lymphohistiocytic infiltrate, intraalveolar hemorrhage, congestion, pulmonary edema, interstitial and intra-alveolar neutrophils infiltration and atelectasis areas, with injuries been scored as absent, mild, moderate or intense. The variables [pCO2(a)], HR, DBP, SBP, MAP, (cNa+), (cK+), (cCa+2), (cCl-), GAP, [cHCO3 -(a)] e [cBase(a)] remained within the physiological values, an [pCO2 (a)] increase and consequent [pH (a)] decrease happens in all animals, and elevated EtCO2 was observed in groups ventilated with higher PEEP and CO2 elimination. It was observed in all groups lymphohistiocytic infiltrate typical of lymphocytic interstitial pneumonia, and low scores for neutrophil infiltration and alveolar interstitial edema, congestion and atelectasis consistent with alveolar capillary endothelium injury. These lesions were more intense in the early times after anesthetic-surgical procedure in the groups GZP and G5P. It is concluded that the increase of the PEEP at 0, 5 and 10 cmH2O cannot prevent acid / base changes promoted by peritoneal CO2 absorption. Positive end-expiratory pressure of 10 cmH2O improves CO2 elimination and reduces CO2 blood pressure, but does not prevent hypercapnia and promotes less intense inflammatory lesions in the lung parenchyma.