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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1768129/
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Severity spectrum
Incipient or preclinical tamponade exists when pericardial pressure equals the normal right, but remains lower than left atrial pressure. When pericardial pressure rises to the level of normal right atrial pressure, cardiac tamponade is trivial; when it equals normal left atrial pressure, tamponade is mild. When pericardial pressure increases further, it reaches left atrial pressure. When pericardial pressure exceeds 10–12 mm Hg, moderate tamponade is present7 and detectable at the bedside by the abnormal jugular pulse and echocardiography that shows compression of the right heart chambers.8 The outer wall of the right atrium becomes concave (right atrial compression)9 and the right ventricular free wall indents toward the septum (right ventricular diastolic collapse) due to transient reversal of the transmural ventricular diastolic pressure.10 At this stage, pulsus paradoxus is often absent and the blood pressure and cardiac output are only slightly lowered. Increased respiratory variation of ventricular filling velocities is more pronounced. This phenomenon is detected by Doppler interrogation of ventricular inflow. For ease of measurement, the change in peak velocity, not velocity–time index or stroke volume, is traditionally used. When tamponade is severe (pericardial pressure more than 25 mm Hg), pulsus paradoxus is prominent, stroke volume and blood pressure are significantly reduced, and sinus tachycardia is usual. With increasing severity of tamponade, haemodynamics decline to the point of shock and, if not promptly treated, death.
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Grandes derrame podem ser chamativos e envolventes para a equipe. Mas sem as pressões elevadas, acima de 25 mmhg, nada de ruim acontece.
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Para ter uma pressão superior a 25 mmhg, tem que ser um derrame inflamatório intenso. Onde a secreção vence a barreira pressórica.
Isso raramente ocorre fora do espectro da inflamação aguda.
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A sobrecarga de volume venosos, com hidratação rigorosa, pode vencer a maioria dos derrames e evitar a quase totalidade das punções e drenagens.
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Experimente correr 1 000 ml de soro aberto antes de puncionar!!!
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