Do pulmonary artery catheters improve patient outcome? No

Equipment review: an appraisal of the LiDCO plus method of measuring cardiac output

The LiDCO plus system is a minimally/non-invasive technique of continuous cardiac output measurement. In common with all cardiac output monitors this technology has both strengths and weaknesses. This review discusses the technological basis of the device and its clinical application.

The esophageal Doppler monitor in mechanically ventilated surgical patients: does it work?

BACKGROUND

Assessment of cardiac volumes and cardiac output (CO) using a pulmonary artery catheter (PAC) in mechanically ventilated patients can be inconsistent and difficult. The esophageal Doppler monitor (EDM) is emerging as a potential alternative to the PAC. This prospective study evaluated the comparative accuracy between the PAC and EDM for preload assessment and CO in mechanically ventilated surgical patients. METHODS The EDM was placed in 15 patients with PACs in place. A total of 187 simultaneously measured EDM and PAC comparative data sets were obtained. The Pearson correlation (r) was used to compare measurements, with significance defined as a value of p < 0.05.

RESULTS

CO measured by EDM and PAC correlated closely (r = 0.97, p < 0.0001). Corrected flow time (FTc), a measure of left ventricular filling, correlated with PAC CO to the same degree as pulmonary capillary wedge pressure (PCWP) when positive end-expiratory pressure (PEEP) was < 10 cm H2O (FTc, r = 0.51; PCWP, r = 0.56). When PEEP was > or = 10 cm H2O, FTc correlated with PAC CO better than PCWP (FTc, r = 0.85; PCWP, r = 0.29).

CONCLUSION

FTc correlates with EDM and PAC CO better than PCWP. On the basis of the current study, it is reasonable to conclude that the EDM is a valuable adjunct technology for CO and preload assessment in surgical patients on mechanical ventilation, regardless of the level of mechanical ventilatory support.

Benefits, risks and alternatives of pulmonary artery catheterization

Twenty-five years after the introduction of the pulmonary artery catheter in clinical practice, its effectiveness in improving patient outcome is seriously questioned. Experts still recommend to use pulmonary artery catheters in selected critically ill patients, although evidence supporting these recommendations is lacking. The risks and the unclear benefits associated with this procedure should prompt the search for alternative, noninvasive monitoring techniques.

The utility of hemodynamic measurements acquired by pulmonary artery catheterization

BACKGROUND

Concerns about the utility of pulmonary artery catheters (PAC) stimulated us to assess the impact of one of the parameters measured by the PAC, the pulmonary capillary wedge pressure (PCWP), on our clinical practice.

METHODS

The PCWP was recorded at 4- to 6-hour intervals on 50 patients for the first 48 hours following aortic aneurysm repair. We then reviewed the patients' records looking for evidence that the PCWP measurements were used to guide therapy. For the purpose of the study, we anticipated the administration of diuretics for PCWP > or =218 mm Hg and volume resuscitation for PCWP < or =8 mm Hg. Data were correlated using Pearson rank correlation coefficient using a P < 0.05 to determine statistical significance.

RESULTS

Patients with PCWPs <8 mm Hg were more likely to be treated with volume resuscitation (P < 0.05). There was no other correlation between PCWP measurements and fluid or pharmacologic management.

CONCLUSIONS

Data derived from the PAC are infrequently used to guide therapy in patients who undergo abdominal aortic reconstructive surgery.