1/4. Cardiovascular collapse associated with extreme iatrogenic PEEPi in patients with obstructive airways disease.Chronic obstructive pulmonary disease (COPD) is commonly associated with positive alveolar pressure at end-expiration (intrinsic PEEP or PEEPi) caused by a prolonged expiratory time constant. Positive pressure ventilation (PPV) with large tidal volumes and high ventilatory frequencies may cause pulmonary hyperinflation, with increases in intrathoracic pressure and cardiopulmonary effects. We report two cases, one of fatal pulseless electrical activity, the other of life-threatening hypotension, both during vigorous manual PPV, in patients with severe COPD. This phenomenon has been well-recognized by intensivists but is reported poorly more widely. ( info) |
2/4. Autocycling and increase in intrinsic positive end-expiratory pressure during mechanical ventilation.Modern ventilators are complicated electronic instruments with microprocessors and software, with the possibility of technical errors and problems such as autocycling. Despite autocycling being recognized as a problem in textbooks and reviews, there are few reports about autocycling in the literature. We report a case where a sudden increase in respiratory frequency due to autocycling resulted in a dangerous increase in intrinsic positive end-expiratory pressure (intrinsic PEEP, PEEPi). We think our case illustrates that autocycling does occur, but that the exact underlying mechanism may be hard to document and understand for clinicians. To remedy this situation, we suggest that manufacture-independent technical expertise should be established to evaluate incidents and suggest improvements. ( info) |
3/4. life-threatening inadvertent positive end-expiratory pressure.Inadvertent positive end-expiratory pressure (PEEP) is a potential cause of lung overdistension and impaired gas exchange in ventilated infants. It can be extremely difficult to diagnose clinically and if unrecognized can be life-threatening. Measurement of lung function can lead to the recognition of inadvertent PEEP, allowing appropriate ventilator adjustment with immediate substantial improvement in clinical state. lung function measurements can help to optimize ventilation and may improve clinical outcome. ( info) |
4/4. Tension pneumoperitoneum after blast injury: dramatic improvement in ventilatory and hemodynamic parameters after surgical decompression.Tension pneumoperitoneum is a known although rare complication of barotrauma, which can accompany blast injury. We report two patients who suffered from severe pulmonary blast injury, accompanied by tension pneumoperitoneum, and who were severely hypoxemic, hypercarbic, and in shock. After surgical decompression of their pneumoperitoneum, respiratory and hemodynamic functions improved dramatically. Several mechanisms to explain this improvement are suggested. In such cases the release of the tension pneumoperitoneum is mandatory, and laparotomy with delayed closure can be contemplated. ( info) |