RESUMO
BACKGROUND: There is debate whether pressure transmission within the lungs and alveolar collapse follow a hydrostatic pattern or the compression exerted by the weight of the heart and the diaphragm causes collapse localized in the areas adjacent to these structures. The second hypothesis proposes the existence of a cephalocaudal gradient in alveolar collapse. We aimed to define whether or not lung density and collapse follow a 'liquid-like' pattern with homogeneous isogravitational layers along the cephalocaudal axis in acute respiratory distress syndrome lungs. METHODS: Acute respiratory distress syndrome patients were submitted to full lung computed tomography scans at positive end-expiratory pressure (PEEP) zero (before) and 25 cmH2 O after a maximum-recruitment maneuver. PEEP was then decreased by 2 cmH2 O every 4 min, and a semi-complete scan performed at the end of each PEEP step. RESULTS: Lung densities were homogeneous within each lung layer. Lung density increased along the ventrodorsal axis toward the dorsal region (ß = 0.49, P < 0.001), while there was no increase, but rather a slight decrease, toward the diaphragm along the cephalocaudal axis and toward the heart. Higher PEEP attenuated density gradients. At PEEP 18 cmH2 O, dependent lung regions started to collapse massively, while best compliance was only reached at a lower PEEP. CONCLUSIONS: We could not detect cephalocaudal gradients in lung densities or in alveolar collapse. Likely, external pressures applied on the lung by the chest wall, organs, and effusions are transmitted throughout the lung in a hydrostatic pattern with homogeneous consequences at each isogravitational layer. A single cross-sectional image of the lung could fully represent the heterogeneous mechanical properties of dependent and non-dependent lung regions.
Assuntos
Pulmão/diagnóstico por imagem , Pulmão/fisiopatologia , Síndrome do Desconforto Respiratório/diagnóstico por imagem , Síndrome do Desconforto Respiratório/fisiopatologia , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Respiração com Pressão Positiva , Alvéolos Pulmonares/diagnóstico por imagem , Alvéolos Pulmonares/fisiopatologia , Decúbito Dorsal/fisiologia , Adulto JovemRESUMO
Our objective was to compare the pattern of organ dysfunctions and outcomes of critically ill patients with systemic lupus erythematosus (SLE) with patients with other systemic rheumatic diseases (SRD). We studied 116 critically ill SRD patients, 59 SLE and 57 other-SRD patients. The SLE group was younger and included more women. Respiratory failure (61 percent) and shock (39 percent) were the most common causes of ICU admission for other-SRD and SLE groups, respectively. ICU length-of-stay was similar for the two groups. The 60-day survival adjusted for the groups’ baseline imbalances was not different (P = 0.792). Total SOFA scores were equal for the two groups at admission and during ICU stay, although respiratory function was worse in the other-SRD group at admission and renal and hematological functions were worse in the SLE group at admission. The incidence of severe respiratory dysfunction (respiratory SOFA >2) at admission was higher in the other-SRD group, whereas severe hematological dysfunction (hematological SOFA >2) during ICU stay was higher in the SLE group. SLE patients were younger and displayed a decreased incidence of respiratory failure compared to patients with other-SRDs. However, the incidences of renal and hematological failure and the presence of shock at admission were higher in the SLE group. The 60-day survival rates were similar.
Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Hematológicas/epidemiologia , Falência Renal Crônica/epidemiologia , Lúpus Eritematoso Sistêmico/complicações , Insuficiência de Múltiplos Órgãos/mortalidade , Transtornos Respiratórios/epidemiologia , Doenças Reumáticas/complicações , Estado Terminal , Métodos Epidemiológicos , Doenças Hematológicas/etiologia , Hospitalização/estatística & dados numéricos , Unidades de Terapia Intensiva , Falência Renal Crônica/etiologia , Tempo de Internação/estatística & dados numéricos , Lúpus Eritematoso Sistêmico/mortalidade , Transtornos Respiratórios/etiologia , Doenças Reumáticas/classificação , Doenças Reumáticas/mortalidadeRESUMO
Our objective was to compare the pattern of organ dysfunctions and outcomes of critically ill patients with systemic lupus erythematosus (SLE) with patients with other systemic rheumatic diseases (SRD). We studied 116 critically ill SRD patients, 59 SLE and 57 other-SRD patients. The SLE group was younger and included more women. Respiratory failure (61%) and shock (39%) were the most common causes of ICU admission for other-SRD and SLE groups, respectively. ICU length-of-stay was similar for the two groups. The 60-day survival adjusted for the groups' baseline imbalances was not different (P = 0.792). Total SOFA scores were equal for the two groups at admission and during ICU stay, although respiratory function was worse in the other-SRD group at admission and renal and hematological functions were worse in the SLE group at admission. The incidence of severe respiratory dysfunction (respiratory SOFA >2) at admission was higher in the other-SRD group, whereas severe hematological dysfunction (hematological SOFA >2) during ICU stay was higher in the SLE group. SLE patients were younger and displayed a decreased incidence of respiratory failure compared to patients with other-SRDs. However, the incidences of renal and hematological failure and the presence of shock at admission were higher in the SLE group. The 60-day survival rates were similar.
Assuntos
Doenças Hematológicas/epidemiologia , Falência Renal Crônica/epidemiologia , Lúpus Eritematoso Sistêmico/complicações , Insuficiência de Múltiplos Órgãos/mortalidade , Transtornos Respiratórios/epidemiologia , Doenças Reumáticas/complicações , Adulto , Estado Terminal , Métodos Epidemiológicos , Feminino , Doenças Hematológicas/etiologia , Hospitalização/estatística & dados numéricos , Humanos , Unidades de Terapia Intensiva , Falência Renal Crônica/etiologia , Tempo de Internação/estatística & dados numéricos , Lúpus Eritematoso Sistêmico/mortalidade , Masculino , Pessoa de Meia-Idade , Transtornos Respiratórios/etiologia , Doenças Reumáticas/classificação , Doenças Reumáticas/mortalidadeRESUMO
AIMS: Organizing pneumonia (OP) is an inflammatory lung disease characterized histologically by intraluminal plugs involving alveolar ducts and alveoli. The aim was to examine extracellular matrix repair and remodelling in 12 cases of idiopathic OP and compare these with 11 cases of secondary OP. METHODS AND RESULTS: Collagen/elastic fibre density, myofibroblast proliferation, microvascular density and endothelial activity in the intraluminal plugs were evaluated by histochemistry, immunohistochemistry and morphometry. The density of the collagen system fibres was greater in plugs of idiopathic OP when compared with secondary OP (P < 0.001). Quantification of myofibroblastic cells confirmed differences observed in patterns of immunoexpression; when compared with secondary OP, idiopathic OP contained fewer myofibroblastic cells in intraluminal plugs (P = 0.01). Microvascular density (CD34) and endothelial activity (vascular cell adhesion molecule-1 and E-selectin) were significantly greater in secondary OP (P < 0.05). CONCLUSIONS: Idiopathic and secondary OP show significant variation in morphological features that may represent different responses to injury. Increased collagen synthesis, low myofibroblast proliferation, poor microvascularization and minimal endothelial activity found in idiopathic OP may be more of a remodelling process than secondary OP repair.