Impact of Grade I obesity on respiratory mechanics during video laparoscopic surgery: prospective longitudinal study / Impacto da obesidade Grau I na mecânica respiratória durante cirurgia videolaparoscópica: estudo longitudinal prospectivo

Abstract Introduction and objectives: The association pneumoperitoneum and obesity in video laparoscopy can contribute to pulmonary complications, but has not been well defined in specific groups of obese individuals. We assessed the effects of pneumoperitoneum in respiratory mechanics in Grade I obese compared to non-obese. Methods: Prospective study including 20 patients submitted to video laparoscopic cholecystectomy, normal spirometry, divided into non-obese (BMI ≤ 25 kg.m-2) and obese (BMI > 30 kg.mg-2), excluding Grade II and III obese. We measured pulmonary ventilation mechanics data before pneumoperitoneum (baseline), and five, fifteen and thirty minutes after peritoneal insufflation, and fifteen minutes after disinflation (final). Results: Mean BMI of non-obese was 22.72 ± 1.43 kg.m-2 and of the obese 31.78 ± 1.09 kg.m-2, p < 0.01. Duration of anesthesia and of peritoneal insufflation was similar between groups. Baseline pulmonary compliance (Crs) of the obese (38.3 ± 8.3 mL.cm H2O-1) was lower than of the non-obese (47.4 ± 5.7 mL.cm H2O-1), p = 0.01. After insufflation, Crs decreased in both groups and remained even lower in the obese at all moments assessed (GLM p < 0.01). Respiratory system peak pressure and plateau pressure were higher in the obese, albeit variations were similar at moments analyzed (GLM p > 0.05). The same occurred with elastic pressure, higher in the obese at all times (GLM p = 0.04), and resistive pressure showed differences in variations between groups during pneumoperitoneum (GLM p = 0,05). Conclusions: Grade I obese presented more changes in pulmonary mechanics than the non-obese during video laparoscopies and the fact requires mechanical ventilation-related care.

Resumo Justificativa e objetivos: Em videolaparoscopias, a associação de pneumoperitônio e obesidade pode contribuir para complicações pulmonares, mas não está bem definida em grupos específicos de obesos. Avaliamos os efeitos do pneumoperitônio na mecânica respiratória dos obesos Grau I em comparação aos não obesos. Métodos: Estudo prospectivo envolvendo 20 pacientes submetidos à colecistectomia videolaparoscópica, com espirometria normal, separados em não-obesos (IMC ≤ 25 kg.m-2) e obesos (IMC > 30 kg.mg-2), excluídos obesos Grau II e III. Mensuramos dados da mecânica ventilatória pulmonar antes do pneumoperitônio basal, após cinco, quinze e trinta minutos da insuflação peritoneal e quinze minutos após a desinsuflação final. Resultados: O IMC médio dos não obesos foi de 22,72 ± 1,43 kg.m-2 e dos obesos 31,78 ± 1,09 kg.m-2, p < 0,01. A duração da anestesia e da insuflação peritoneal foram semelhantes entre os grupos. A complacência pulmonar (Crs) basal dos obesos (38,3 ± 8,3 mL.cm H2O-1) foi inferior aos não obesos (47,4 ± 5,7 mL.cm H2O-1), p = 0,01. Após a insuflação, a Crs diminuiu nos dois grupos e permaneceu ainda mais baixa nos obesos em todos os momentos avaliados (GLM p < 0,01). A pressão de pico e a pressão de platô do sistema respiratório foram mais elevadas nos obesos, mas apresentaram semelhantes variações nos momentos analisados (GLM p > 0,05). O mesmo ocorreu com a pressão elástica, mais elevada nos obesos em todos tempos (GLM p = 0,04), e a pressão resistiva apresentou diferenças nas variações entre os grupos durante o pneumoperitônio (GLM p = 0,05). Conclusão: Obesos Grau I apresentam maiores alterações na mecânica pulmonar que os não obesos em videolaparoscopias e este fato recomenda cuidados relacionados a ventilação mecânica.

[Impact of Grade I obesity on respiratory mechanics during video laparoscopic surgery: prospective longitudinal study]. / Impacto da obesidade Grau I na mecânica respiratória durante cirurgia videolaparoscópica: estudo longitudinal prospectivo.

INTRODUCTION AND OBJECTIVES: The association pneumoperitoneum and obesity in video laparoscopy can contribute to pulmonary complications, but has not been well defined in specific groups of obese individuals. We assessed the effects of pneumoperitoneum in respiratory mechanics in Grade I obese compared to non-obese. METHODS: Prospective study including 20 patients submitted to video laparoscopic cholecystectomy, normal spirometry, divided into non-obese (BMI ≤ 25kg.m-2) and obese (BMI > 30kg.mg-2), excluding Grade II and III obese. We measured pulmonary ventilation mechanics data before pneumoperitoneum (baseline), and five, fifteen and thirty minutes after peritoneal insufflation, and fifteen minutes after disinflation (final). RESULTS: Mean BMI of non-obese was 22.72 ± 1.43kg.m-2 and of the obese 31.78 ± 1.09kg.m-2, p < 0.01. Duration of anesthesia and of peritoneal insufflation was similar between groups. Baseline pulmonary compliance (Crs) of the obese (38.3 ± 8.3mL.cm H2O-1) was lower than of the non-obese (47.4 ± 5.7mL.cm H2O-1), p = 0.01. After insufflation, Crs decreased in both groups and remained even lower in the obese at all moments assessed (GLM p < 0.01). Respiratory system peak pressure and plateau pressure were higher in the obese, albeit variations were similar at moments analyzed (GLM p > 0.05). The same occurred with elastic pressure, higher in the obese at all times (GLM p = 0.04), and resistive pressure showed differences in variations between groups during pneumoperitoneum (GLM p = 0,05). CONCLUSIONS: Grade I obese presented more changes in pulmonary mechanics than the non-obese during video laparoscopies and the fact requires mechanical ventilation-related care.

Temporal evolution of epithelial, vascular and interstitial lung injury in an experimental model of idiopathic pulmonary fibrosis induced by butyl-hydroxytoluene.

This study was undertaken to test whether the structural remodelling of pulmonary parenchyma can be sequentially altered in a model and method that demonstrate the progression of the disease and result in remodelling within the lungs that is typical of idiopathic pulmonary fibrosis. Three groups of mice were studied: (i) animals that received 3-5-di-tert-butyl-4-hydroxytoluene (BHT) and were killed after 2 weeks (early BHT = 9); (ii) animals that received BHT and were killed after 4 weeks (late BHT = 11); (iii) animals that received corn oil solution (control = 10). The mice were placed in a ventilated Plexiglas chamber with a mixture of pure humidified oxygen and compressed air. Lung histological sections underwent haematoxylin-eosin, immunohistochemistry (epithelial, endothelial and immune cells) and specific staining (collagen/elastic fibres) methods for morphometric analysis. When compared with the control group, early BHT and late BHT groups showed significant decrease of type II pneumocytes, lower vascular density in both and higher endothelial activity. CD4 was increased in late BHT compared with early and control groups, while CD8, macrophage and neutrophil cells were more prominent only in early BHT. The collagenous fibre density were significantly higher only in late BHT, whereas elastic fibre content in late BHT was lower than that in control group. We conclude that the BHT experimental model is pathologically very similar to human usual interstitial pneumonia. This feature is important in the identification of animal models of idiopathic pulmonary fibrosis that can accurately reflect the pathogenesis and progression of the human disease.

Efeitos do resíduo da queima de óleo diesel (ROFA) e da inflamação pulmonar alérgica crônica em três linhagens de camundongos / Effects of residual diesel oil fly ash (ROFA) and pulmonary allergic chronic inflammation in tree lines of mice

Neste estudo, foram realizados três experimentos distintos (1) analisando os efeitos da administração de material particulado em camundongos BALB/c com inflamação pulmonar alérgica crônica induzida por ovalbumina; (2) comparando camundongos AIRmax e AIRmin com inflamação pulmonar alérgica crônica induzida por ovalbumina; (3) comparando camundongos AIRmax e AIRmin que receberam material particulado (resíduo da queima de óleo diesel - ROFA) por via intranasal. Para a indução da inflamação pulmonar alérgica crônica, os camundongos foram sensibilizados com ovalbumina (OVA) através de duas injeções intraperitoneais de alérgeno com o adjuvante hidróxido de alumínio (dias 0 e 14) e quatro inalações de OVA 1% (dias 22, 24, 26 e 28). Os animais que foram expostos ao material particulado, receberam ROFA (60 ?g) nos dias 0, 2, 4 e 6 no experimento do efeito do material particulado ou nos dias dos desafios com OVA no experimento do efeito da administração de material particulado em animais com inflamação pulmonar induzida pela OVA. Os grupos controle foram tratados com solução salina 0,9 % seguindo o mesmo protocolo. Quarenta e oito horas após o último desafio, a responsividade pulmonar foi medida por broncoprovocação àr metacolina através da pletismografia de corpo inteiro, após a qual os animais foram sacrificados e tiveram os pulmões removidos para analise histológica. O estudo realizado com animais BALB/c para análise dos efeitos do material particulado sobre a resposta inflamatória induzida pela ovalbumina mostrou um aumento de responsividade nos animais inflamados e co-expostos ao material particulado, sem efeito sobre a inflamação ou remodelamento epitelial induzidos pela OVA. A exposição ao material particulado por si só levou a uma diminuição da área ocupada por células ciliadas e a um aumento da responsividade pulmonar...

In this study, three distinct experiments were performed (1) examining the effects of administration of particulate matter in BALB/c mice with chronic allergic pulmonary inflammation induced by ovalbumin; (2) comparing AIRmax and AIRmin mice with chronic allergic pulmonary inflammation induced by ovalbumin; (3) comparing AIRmax and AIRmin mice receiving particulate matter (residue from the burning of diesel oil - ROFA) intranasally. For the induction of chronic allergic pulmonary inflammation, the mice were sensitized to ovalbumin (OVA) through two intraperitoneal injections of allergen with adjuvant aluminum hydroxide (days 0 and 14) and four inhalations of OVA 1% (days 22, 24, 26 and 28). The animals that were exposed to particulate matter received ROFA (60 ?g) on days 0, 2, 4 and 6 in the study of the effect of the particulate matter or after the challenges with OVA in experiment of the effect of administration of particulate matter in animals with pulmonary inflammation induced by OVA. The control groups were treated with saline 0.9% following the same protocol. Forty eight hours after the last challenge, pulmonary responsiveness was measured through broncoprovocation to methacholine by whole body plethysmography, after which the animals were sacrificed and the lungs were removed for histologic analysis. The study conducted on animals BALB/c for analysis of the effects of particulate matter on the inflammatory response induced by ovalbumin showed an increase of responsiveness in animals with allergic inflammation and exposed to the particulate matter, without effects on inflammation or epithelial remodeling induced by OVA. Exposure to particulate matter led to a reduction in the area occupied by ciliated cells and increased lung responsiveness. The experiment in AIRmax AIRmin mice to study possible differences in the response of these...