CURRENT Essentials of Critical Care.pdf

74 Current Essentials of Critical Care■■■Cardiac Compressive ShockEssentials of Diagnosis• Low cardiac output state caused by compression of heart or greatvessels• Hypotension, tachycardia, cool extremities, elevated neck veins,pulsus paradoxus, distant heart sounds, oliguria, altered mentalstatus• ECG with reduced amplitudes; may have electrical alternans• “Water bottle” shaped cardiac silhouette on chest radiograph• Echocardiogram demonstrates fluid within pericardium causingright cardiac chamber collapse• Pulmonary artery catheter reveals equalization of central venous,pulmonary capillary, and pulmonary artery diastolic pressureswith low cardiac index• Cardiac tamponade most common cause; accumulation of fluidin pericardial sac sufficient to prevent filling of cardiac chambers• Causes of cardiac tamponade: malignancy, trauma, uremia, connectivetissue disorders, uremia, infection, idiopathic pericarditisDifferential Diagnosis• Restrictive cardiomyopathy • Constrictive pericarditis• Right ventricular infarction • Tension pneumothorax• Left ventricular failureTreatment• Intravascular volume expansion with intravenous fluids• Immediate drainage of pericardial effusion via pericardiocentesis• Pericardial catheter can be left in place for period of days forongoing drainage• Surgical or percutaneous balloon pericardial window can be performedfor definitive treatment depending on cause of effusionand rapidity of reaccumulation■ PearlThe cardinal finding of elevated neck veins in cardiac tamponade maybe absent in the volume depleted patient.ReferenceBogolioubov A et al: Circulatory shock. Crit Care Clin 2001;17:697. [PMID:11525054]