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Objective: To determine the effects of intravenous N-acetylcysteine (NAC) on the development of severe adult respiratory distress syndrome (ARDS) and mortality rate in patients with mild-to-moderate acute lung injury and [...]

Attenuation of ventilator-synchronous pressure fluctuations of intracranial pressure has been demonstrated during high frequency ventilation in animal and human studies, but the consequences of this effect on cerebral blood flow [...]

The ventricular volume and function changes induced by the addition of 12 cm H2O of positive end-expiratory pressure (PEEP) during mechanical ventilation were studied in 11 patients with the adult respiratory distress syndrome. Cardiac output was measured by thermodilution and ventricular ejection fraction by the multiple gated equilibrated cardiac blood pool scintigraphy. Right and left end-diastolic volumes were then calculated by dividing stroke volume by ejection fraction. The PEEP caused a 14 percent decrease of the cardiac output secondary to a decrease in stroke volume. On the basis of the relationship between stroke volume and ventricular end-diastolic volume, we conclude that reduction in preload was the major component of the decrease in cardiac output. After removal of PEEP, we observed a rebound phenomenon characterized by higher values for stroke volume and cardiac output than before the application of PEEP.

In 12 patients requiring therapy with mechanical ventilation for acute respiratory failure, total static compliance (Cst) increased from 29 ± 4 ml/cm H2O at a tidal volume (TV) of 5 ml/kg to 42 ± 7 ml/cm H2O at a TV of 15 ml/kg. Similarly, Cst increased from 42 ± 7 ml/cm H2O to 52 ± 8 ml/cm H2O between 0 and 6 cm H2O of positive end-expiratory pressure (PEEP). At high levels of pulmonary inflation (ie,high PEEP and large TV) compliance decreased. The changes of total respiratory compliance with TV were mainly due to changes in pulmonary compliance. With PEEP, the functional residual capacity increased, and specific compliance did not change. Two mechanisms may be responsible for the changes in compliance. First, varying TV or PEEP will alter the position of tidal ventilation on the pressure-volume curve, resulting in an increase in compliance with increasing TV and PEEP up to a point, where overdistention occurs and compliance decreases. Secondly, the function of the surface-lowering substance may be altered in acute pulmonary parenchymal disease, thus disturbing the regulation of surface tension over the range of pulmonary Inflation studied.

Because of metastatic pain resistant to medical treatment after left pneumonectomy for squamous cell carcinoma, a 46-year-old patient underwent a bilateral cervical cordotomy at the C1-C2 anterolateral level, in two phases. The second intervention was followed by severe ventilatory problems requiring mechanical ventilation, and at a later stage, the implantation of a phrenic pacemaker on the right side. Analysis of the ventilatory pattern during spontaneous breathing and during phrenic pacing and measurement of the transdiaphragmatic pressure during phrenic nerve stimulation revealed the existence of a beneficial effect of aminophylline on both the regulation of ventilation and diaphragmatic contractility.