Routine daily chest radiography in patients with pulmonary artery catheters

Pulmonary artery catheters are widely used invasive monitoring devices in critically ill patients. Clinicians disagree about whether daily chest radiographs are needed or clinical parameters alone are sufficient to verify catheter placement.

To determine whether daily chest radiographs are needed to assess migration of pulmonary artery catheters.

One hundred consecutive patients with pulmonary artery catheters were prospectively evaluated. Clinical criteria for optimal position of the pulmonary artery catheters and findings on chest radiographs were compared. Optimal clinical criteria were (1) amount of air required to measure pulmonary capillary wedge pressure: 1.25 to 1.5 mL and (2) pulmonary artery catheter migrated 1 cm or less from initial position.

Three hundred ninety comparisons of clinical criteria and radiographic findings were done. Chest radiographs indicated the catheter required repositioning in 15 (4%) of 390 instances but in only 4 (1%) of 310 instances in which bedside clinical findings indicated adequate catheter position. In 69 (18%) of the 390 cases, the clinical criteria for adequate catheter position were not met, but radiographs showed the catheter in an appropriate position. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of abnormal clinical criteria were 73%, 82%, 81%, 14%, and 99%, respectively.

Chest radiographs indicated that about 4% of catheters required repositioning. Catheter malposition can be reliably excluded (negative predictive value, 99%) by close observation of specific clinical criteria, so routine daily chest radiographs do not seem justified.