Chest
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Pulse oximetry has made a significant contribution to noninvasive monitoring in a wide variety of clinical situations. It allows for continuous reliable measurements of oxygen saturation while avoiding the discomfort and risks of arterial puncture. As the extent of hypoxic episodes during various procedures and clinical settings is better appreciated, the role of continuous noninvasive monitoring will undoubtedly expand. An understanding of the principles and technology of pulse oximetry will allow physicians to obtain maximal clinical benefit from its use.
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Intensive management of patients with severe head injury offers the best hope of minimizing death and functional disability in a young, working population. Secondary neurologic insult can be decreased by cardiorespiratory support and ICP control from the outset. ⋯ Care should not be withheld because of initially grim (and inaccurate) prognostic assessment. Newer techniques for assessing the adequacy of cerebral circulation may allow refinement of management strategies in the future.
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Review
Medical management and therapy of bronchopleural fistulas in the mechanically ventilated patient.
Bronchopleural fistulas are associated with high morbidity and mortality and are particularly challenging in the ventilated patient. Familiarity with both basic and more technical medical management techniques may lessen morbidity and improve survival. ⋯ Appropriate conventional ventilator manipulations aimed at decreasing fistula air leak and maintaining adequate oxygenation and ventilation may fail and necessitate a trial of HFV. Definitive therapy by the bronchoscopic application of a sealing agent to occlude the fistula site can be used, particularly in the poor surgical candidate.
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Breathing is controlled by an automatic brain-stem controller acted on by higher neural influences that stabilize breathing and compensate for neuromechanical abnormalities. Loss of this wakefulness-dependent descending influences during nonrapid eye movement (NREM) sleep results in the appearance of a hypocapnic apnea threshold, which is associated with periodic breathing when the gain of chemical feedback loops is high. ⋯ REM sleep poses different problems for the respiratory control system owing to muscular atomia and suppression of chemical feedback. These changes are associated with respiratory deterioration in patients with compromised diaphragmatic function, eg, patients with chronic obstructive pulmonary disease.