Recent observational studies suggest that the use of pulmonary artery catheters to guide treatment is associated with increased mortality. Outcomes have been confounded by the severity of the underlying illness. This multicentre, randomised, controlled clinical trial involving blinded assessment of outcomes compared treatment guided by a pulmonary artery catheter with standard treatment (not guided by a pulmonary artery catheter) in 1994 at risk elderly patients (American Society of Anaesthesiologists class III and IV risk) undergoing surgery followed by a stay in the intensive care unit (ICU). Patients were aged ≥60 years and were scheduled for urgent or elective major abdominal, thoracic, vascular, or hip fracture surgery. There was no difference between the two groups in rate of in-hospital mortality, length of hospital stay (median 10.0 days for both), or survival at 6 or 12 months. However, there was a higher rate of acute pulmonary embolism in the catheter group (8 v 0, p=0.004).

The study showed that, in this group of patients, medical management directed by pulmonary artery catheters had no advantage over standard treatment. Whether the results of this study extend to patients other than those at high risk is not at present known.