Critical care : the official journal of the Critical Care Forum
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The haemodynamic as well as the ventilatory consequences of mechanical ventilation can be harmful in critically ill neonates. Newly developed ventilatory lung protective strategies are not always available immediately and in an acute situation the haemodynamic changes caused by mechanical ventilation can affect the oxygen delivery considerably. We report the case of a male neonate who was treated with conventional pressure-controlled mechanical ventilation because of respiratory distress and progressive respiratory acidosis resulting from meconium aspiration. Because of poor arterial oxygenation despite 100% inspired oxygen and increased ventilator settings, echocardiography was performed to exclude central haemodynamic reasons for low oxygen delivery. ⋯ Because oxygen delivery is dependent on both blood flow and arterial oxygen content, measurement of cardiac output as well as left heart oxygen saturation is a useful guide to optimizing oxygen delivery. This case report demonstrates how Doppler echocardiographic monitoring of beat-to-beat changes in stroke volume can be used to detect early negative haemodynamic effects of increased mechanical ventilation settings before cardiac output is affected.
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Hypoxic pulmonary vasoconstriction continues to attract interest more than half a century after its original report because of persistent mystery about its biochemical mechanism and its exact physiological function. Recent work suggests an important role for pulmonary arteriolar smooth muscle cell oxygen-sensitive voltage-dependent potassium channels. ⋯ However, refined modeling of hypoxic pulmonary vasoconstriction operating as a feedback mechanism in inhomogeneous lungs, using more realistic stimulus-response curves and confronted with direct measurements of regional blood flow distribution, shows a more effective than previously assessed ability of this remarkable intrapulmonary reflex to improve gas exchange and arterial oxygenation. Further studies could show clinical benefit of pharmacological manipulation of hypoxic pulmonary vasoconstriction, in circumstances of life-threatening hypoxemia.
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Randomized Controlled Trial Clinical Trial
Atrial natriuretic peptide infusion and nitric oxide inhalation in patients with acute respiratory distress syndrome.
To study the effects of infusion of atrial natriuretic peptide (ANP) versus the inhalation of nitric oxide (NO) in patients with an early acute respiratory distress syndrome (ARDS). ⋯ This study shows that, in contrast to NO inhalation, infusion of ANP neither improves oxygenation nor attenuates pulmonary hypertension or pulmonary edema in patients with severe ARDS.
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Randomized Controlled Trial Clinical Trial
Biphasic positive airway pressure ventilation (PeV+) in children.
Biphasic positive airway pressure (BIPAP) (also known as PeV+) is a mode of ventilation with cycling variations between two continuous positive airway pressure levels. In adults this mode of ventilation is effective and is being accepted with a decrease in need for sedatives because of the ability to breathe spontaneously during the entire breathing cycle. We studied the use of BIPAP in infants and children. ⋯ BIPAP is an effective, safe and easy to use mode of ventilation in infants and children.
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The 21st International Symposium on Intensive Care and Emergency Medicine was dominated by the results of recent clinical trials in sepsis and acute respiratory distress syndrome (ARDS). The promise of extracorporeal liver replacement therapy and noninvasive ventilation were other areas of interest. ⋯ Overall, the 'state of the art' lectures, pro/con debates, seminars and tutorials were of a high standard. The meeting was marked by a sense of renewed enthusiasm that positive progress is occurring in intensive care medicine.