Intensive care medicine
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Intensive care medicine · Mar 1982
Comparative StudyA comparative study of the cardiorespiratory effects of continuous positive airway pressure breathing and continuous positive pressure ventilation in acute respiratory failure.
Positive end expiratory pressure (PEEP) produces cardiopulmonary effects whether administered by controlled positive pressure ventilation (CPPV) or continuous positive airway pressure (CPAP). In eight patients with acute respiratory failure, the effects of 20 cm PEEP administered via CPPV and CPAP were compared. An esophageal balloon was used to calculate the transmural vascular pressures. ⋯ The two different modes of ventilation (CPPV and CPAP) gave identical blood gas improvement through the same level of end expiratory transpulmonary pressure despite marked differences between absolute mean airway and esophageal pressures. Conversely, hemodynamic tolerance was very different from one technique to the other: CPPV depressed cardiac index from 3.4 +/- 0.3 to 2.4 +/- 0.2 1/min/m2 as well as decreasing transmural filling pressures, suggesting a reduction in venous return. Conversely, filling pressures maintained at control values during CPAP and cardiac indexes were unchanged.
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Intensive care medicine · Mar 1982
Epidural analgesia or mechanical ventilation for multiple Rib fractures?
A protocol for treating thoracic trauma is proposed. Severe pulmonary lesion with increased venous admixture (e.g. contusio, atelectasis, aspiration) is treated by mechanical ventilation. Rib fractures with minor pulmonary lesion and therefore with only moderately abnormal gas exchange but with remarkably reduced vital capacity (even with flail chest) are controlled by thoracic epidural analgesia following vital capacity, tidal volume and respiratory rate. ⋯ The indication for a mechanical ventilation or for spontaneous breathing with thoracic epidural analgesia is therefore deducted more from functional variables than from morphological facts. The course of a consecutive series of 283 patients is presented. 155 patients were treated with primary ventilation and 112 patients with primary epidural analgesia, while 16 patients could be managed with general analgesia. The duration of treatment morbidity and mortality show this protocol to be very useful.
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Intensive care medicine · Mar 1982
The influence of PEEP ventilation on organ blood flow and peripheral oxygen delivery.
In an experimental study including 10 dogs with intact lungs (group I) and 10 dogs with oleic acid-induced pulmonary edema (group II), the effects of PEEP 10 and 20 (cm H20) on central hemodynamics, lung function, organ blood flow and tissue PO2 (liver and skeletal muscle) were examined. In both groups, PEEP resulted in a significant fall of cardiac output (CO) despite volume substitution. ⋯ Animals with pulmonary edema and consequently lower absolute values of CO showed a more uniform reduction of organ perfusion sparing only brain and heart PEEP 10 led to a marginal improvement of tissue oxygenation, whereas PEEP 20 resulted in a deterioration of local PO2 associated with a decrease in O2 transport. It is concluded that whenever PEEP is applied, a reduction and redistribution of CO may occur possibly jeopardizing tissue oxygenation and thus interfering with organ function.