1997 OPEN FORUM Abstracts
Use of Invasive Monitoring in a Patient in Acute Respiratory Failure
John W Hoyt MD, Charles G Durbin Jr. MD, Sunday, December 7, 1997.
Both respiratory and cardiac disease can result in similar respiratory gas exchange abnormalities. Even the physical exam and chest radiographs are often non-specific and the caregiver is unable to separate pulmonary dysfunction from any cardiac contribution. Also, diseases and treatments of the pulmonary system alter cardiac function and vice versa. Use of data derived from a pulmonary artery catheter can allow differentiation of cardiac from respiratory disease. Furthermore, derived data including cardiac output and vascular resistances permits the clinician to appropriately tailor therapy in these complicated critically ill patients.
The majority of patients requiring mechanical ventilation or cardiac support may not benefit from placement of a pulmonary artery catheter. However, patients who fail to respond to appropriate empirical treatment often will improve when management is based on data obtained from this device. Patient selection and timing of catheterization are important factors in management of critical illness and these decisions will affect outcome and cost of care.
Recently, the use of pulmonary artery catheters has come under medical and political scrutiny. Some influential authors have even suggested that a moratorium be placed on this use of this device. This recommendation was based on an outcome study which identified widely varying patterns of use of this device among different institutions with patients having a similar degree of illness. No association with improved outcome could be identified for any disease-specific group. There was a suggestion that in low risk, less ill patients the catheter might even be associated with a poorer outcome.
This study has major flaws: 1) There was no evaluation of whether data obtained from the device was actually used for clinical decision making. 2) There was no report of the quality of the data obtained from this device. 3) A case matching technique was used. The success of patient population matching is in doubt. And, 4) This study only examined the use of the pulmonary artery catheter placed on the first ICU day, many patients in the matched control group later received the device. Several expert panels have evaluated the published literature and made recommendations on when to use a PA catheter and what additional studies need to be performed.
This presentation will analyze a clinical case in which pulmonary artery catheterization provided essential information for both diagnosis and treatment of a patient receiving mechanical ventilation. Decision points and options will be discussed. Care of critically ill patients with respiratory and cardiac compromise can be improved with knowledge of parameters only available through placement of a pulmonary artery catheter. The results of the recent consensus conferences on the use of this device in clinical practices will be part of this presentation.
AARC 50th Anniversary, December 6 - 9, 1997, New Orleans, Louisiana.