Intensive care medicine
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Intensive care medicine · Jan 1992
Comparative StudyA comparison of continuous positive pressure ventilation, combined high frequency ventilation and airway pressure release ventilation on experimental lung injury.
In pigs with oleic induced lung injury, the effectiveness of combined high frequency ventilation (CHFV, with VDR-Phasitron) and airway pressure release ventilation (APRV) were compared to continuous positive pressure ventilation (CPPV) in a randomized study. The respiratory rate was 15/min, CPAP 8 mmHg and FiO2 0.25. PaCO2 was maintained at 5 kPa. ⋯ There was no difference in the pericardiac pressure between the 3 ventilation modes. The pressure related depressive effects on the cardiovascular function during CHFV and APRV were similar to those during CPPV. Adequate oxygenation and ventilation could be achieved with both CHFV and APRV, but these methods were not superior to CPPV.
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Intensive care medicine · Jan 1992
Inspiratory work imposed by continuous positive airway pressure (CPAP) machines: the effect of CPAP level and endotracheal tube size.
Inspiratory work imposed by Continuous Positive Airway Pressure (CPAP) machines has been a matter of concern. The imposed inspiratory work of CPAP machine circuits (Wcir) and the effect of the total breathing apparatus with endotracheal tube (ETT) and connector included in the circuit (Wapp), were measured in three continuous flow (CF) and various configurations of three demand flow (DF) CPAP machines. The performance was assessed at 0, 5, 10 and 15 cmH2O CPAP using a Michigan Instruments Test Lung Model 1600, internal compliance set at 50 ml/cmH2O, driven at square wave inspiratory flows (VI) of 20, 40 and 60 l/min at a tidal volume of 500 ml. ⋯ No consistent advantage of CF over DF machines was demonstrated. There was little advantage of high gas flows (greater than 5 l/min) in various DF circuits. Within an individual machine maximum negative pressures generated during inspiration correlated with both Wcir and Wapp.
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Intensive care medicine · Jan 1992
Case ReportsThe effect of sedation with propofol on postoperative bronchoconstriction in patients with hyperreactive airway disease.
Two patients with chronic obstructive pulmonary disease developed postoperatively bronchospasm after insertion of a prostetic aortic valve. Continuous sedation with propofol infusion was associated with a significant decline in peak inspiratory pressure suggesting that propofol may have bronchodilating properties.
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Intensive care medicine · Jan 1992
Case ReportsDifferential lung ventilation with a double-lumen tracheostomy tube in unilateral refractory atelectasis.
Two patients with refractory hypoxemia due to unilateral lung atelectasis were treated with differential lung ventilation (DLV) through a Robertshaw-type, double-lumen tracheostomy tube. DLV was applied using two non-synchronized ventilators and maintained for 6 and 3 days, respectively. Ventilator settings were chosen in accord to the clinical, laboratory and chest X-rays results. ⋯ We also observed an improvement of SvO2, O2AVI, PVRI and Qva/Qt values (Case 1). The tracheostomy tube used to apply DLV was very reliable, allowing easy nursing care and selective bronchial aspirations. We conclude that DLV is a very useful technique in unilateral lung pathology, and it can be a life saving procedure in selected patients, by supplying volume and PEEP more efficiently to the affected lung.
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Intensive care medicine · Jan 1992
Intrathoracic blood volume accurately reflects circulatory volume status in critically ill patients with mechanical ventilation.
Positive pressure ventilation in patients with acute respiratory failure (ARF) may render the interpretation of central venous pressure (CVP) or pulmonary wedge pressure (PCWP) difficult as indicators of circulating volume. The preload component of cardiac (CI) and stroke index (SI) is also influenced by the increased intrathoracic pressures of positive pressure ventilation. Moreover CI and SI do not indicate volume status exclusively but also contractility and afterload. ⋯ All data were collected in intervals of 6 h. There were 224 data sets obtained. Linear regression analysis was performed between absolute values as well as between the 6 changes (prefix delta).(ABSTRACT TRUNCATED AT 250 WORDS)