RT Book, Section A1 Leatherman, James W. A1 Marini, John A2 Hall, Jesse B. A2 Schmidt, Gregory A. A2 Kress, John P. SR Print(0) ID 1126247244 T1 Interpretation of Hemodynamic Waveforms T2 Principles of Critical Care, 4e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 9780071738811 LK accesssurgery.mhmedical.com/content.aspx?aid=1126247244 RD 2024/03/29 AB Randomized trials have found that use of a pulmonary artery catheter did not influence the mortality of critically ill patients with shock or acute respiratory distress syndrome.Although measurement of right atrial (central venous) pressure (Pra) is a central component of early goal-directed therapy for septic shock, use of the Pra to guide hemodynamic management is controversial.Partial wedging can lead to marked overestimation of the pulmonary artery wedge pressure (Ppw) and should be suspected when the measured Ppw exceeds the pulmonary artery diastolic pressure (Ppad). With pulmonary hypertension, partial wedging may be present despite a positive Ppad-Ppw gradient and should be suspected when the latter markedly narrows in comparison with previous values.Positive end-expiratory pressure (PEEP) and active expiration cause the measured Ppw and Pra to overestimate transmural pressure, with active expiration resulting in greater errors. Simultaneous recording of bladder pressure and Pra (or Ppw) can be helpful for assessing the impact of active expiration on transmural pressure.Hemodynamic waveforms may be helpful in the diagnosis of certain cardiac disorders: Large v waves in the Ppw tracing are seen in acute mitral regurgitation, but can also occur with hypervolemia. Cardiac tamponade is characterized by equalization of the Ppw and right atrial pressure (Pra) with blunting of the y descent. Tricuspid regurgitation often produces a broad c-v wave and a prominent y descent. Inspection of the Pra during narrow complex tachycardias may be helpful if flutter waves or regular cannon a waves (supraventricular reentrant tachycardia) are seen.Neither the Pra nor the Ppw are reliable predictors of fluid responsiveness. However, failure of the Pra to fall with spontaneous inspiration indicates that the patient is unlikely to benefit from a fluid challenge.