More Than a Number

A 68-year-old woman with a history of schizophrenia, severe coronary artery disease, hypertension, and type 2 diabetes mellitus was found in her bed minimally responsive by staff at the group home where she lived. She had been discharged from the hospital two days earlier with a diagnosis of segmental pulmonary embolism and on Coumadin anticoagulation. Lower extremity Doppler ultrasounds were negative for deep vein thrombosis during that hospitalization.   EMS brought her to the emergency department, and had intubated for airway protection. She was febrile, tachycardic, and hypotensive, and had a hemoglobin of 4 g/dL. An abdomen/pelvis CT revealed a large retroperitoneal hematoma. She was admitted to the ICU in critical condition. She was fluid resuscitated, and started on norepinephrine. A central venous catheter was placed, and the EKG strip shown was obtained.   Central venous pressure (CVP) reflects the right atrial pressure and by inference the right ventricular filling pressure. Using the Frank-Starling relationship, higher filling pressures are required to generate larger right ventricular stroke volumes or to maintain the same stroke volume in the setting of right ventricular dysfunction. Unfortunately, there is a tendency to concentrate only on this average value. A tracing of the central venous pressure shows a series of waves. If we understand the origins of these waves, close observation of the waveform can provide invaluable additional hemodynamic informati...
Source: Spontaneous Circulation - Category: Emergency Medicine Tags: Blog Posts Source Type: blogs