Evaluation of the effects of long term prone positioning on mechanically ventilated patients with a cute respiratory failure

Acute respiratory failure [ARF] is one of the commonest potentially Lethal disease processes encountered in critical care Medicine. When the fraction of inspired oxygen [FIO[2]] requirement to correct hypoxemia exceeds 0.60, efforts should be made to improve the efficiency of pulmonary gas exchange. The use of prone position was proposed to improve arterial oxygenation in many studies. This study aimed to evaluate the effects of long term prone positioning on arterial oxygenation and respiratory mechanics in mechanically ventilated patients with acute respiratory failure. Thirty patients suffering from acute respiratory failure were enrolled in this study. Patients were subjected to lung injury score, arterial gasometry, oxygen index and respiratory mechanics including peak inspiratory pressure, plateau pressure, static and dynamic compliance and airway resistance. All parameters measured in supine and position [one hour, two hours, three hours and four hours]. The mean [SD] age for the patients was 45.17 [16.65]. The mean [SD] lung injury score for the whole patients was 2.36[0.73]. The study showed significant increase in arterial oxygen tension and oxygenation index by prone positioning of patients. Both static and dynamic compliance were significantly increased in the four hours of prone position. Airway resistance, peak inspiratory pressure and plateau pressure showed insignificant reduction in prone position. Prone position in mechanically ventilated patients with acute respiratory failure [ARF] improves oxygenation to a clinically important extent and also increases both static and dynamic compliance

Interleukin-5 production by peripheral blood monocytes from asthmatic patients: effect of alveolar macrophages

This study aimed to assess the role of ALM in the pathogenesis of bronchial asthma by studying the effect of ALM derived from bronchoalveolar lavage [BAL] on IL-5 production by peripheral blood monocytes PBMC [including T lymphocytes] in cocultures in patients with bronchial asthma as compared to that in non asthmatic individuals. Nineteen patients with bronchial asthma were enrolled in this study. Ten normal non-smoker subjects were considered as controls. Patients were subjected to broncoalveolar lavage [BAL]. The lavage fluid was cultured in 3 wells; one with peripheral blood monocytes [PBMC], another with PBMC with mitogen stimulation and the third with PBMC with BAL cells and stimulation. Cultures were incubated and the supernatants were assayed for IL-5 by EL1SA. The mean [SD] age for the asthmatic patients was 37.67[9.66] years with a mean [SD] body mass index of 28.3[6.12]. Male constituted 53% [11/19] of the studied asthmatic patients. The levels of 1L-5 in the supernatant of resting PBMN cultures were significantly higher in patients with asthma in all three states [basal state, after PHA stimulation, in cocultures with ALM [mean [SD] = 219.45[68.34] ng/ml, range [100-320 ng/ml], 484.85[115048.01], range [170-670 ng/ml], 1118 [336.59], range [530-1800 ng/ml], respectively. The respective levels in the nonatopic normal subjects was [mean [SD]: 21.20[8.97], 26.8[10.10], 29.30[7.87]]. The differences between the three states in the asthmatic patients were highly significant. The changes between the three states in the non-asthmatic patients were insignificant. IL5 production by PBMN is markedly increased in asthmatic patients versus non-asthmatic subjects, furthermore, IL-5 production was markedly amplified by co-culturing PBMN with autologous ALM derived from BAL in the asthmatics patients. This is in contrast to the finidings in non-asthmatic subjects where IL5 production was not augmented by autologous ALM. The fact that ALM from non-asthmatic subjects functioned poorly as APC may represent a local inhibitory protective mechanism in the airways