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Abstract

The use of pulmonary artery catheters is under debate yet again. We look at two recent trials evaluating their impact on mortality. Our suspicions regarding obesity are proven and we also look at a simple, cost effective method of reducing ventilator-associated pneumonia. Finally, an intervention to improve the poor outcome associated with out-of hospital cardiac arrests is evaluated. A dying Swan: FACTT or fiction?The invention of the pulmonary artery catheter (PAC) 38 years ago by Drs Jeremy Swan and William Ganz was embraced by the medical world wholly and enthusiastically. It was presumed that the increased information provided would help deliver a more tailored and scientific approach to our critically unwell patients. However, concerns regarding their usefulness and safety are increasingly evident [1], and, with the development of alternative tools to calculate haemodynamic parameters, the use of the PAC is dwindling.The latest study to question their use compares PAC to central venous catheter (CVC) guided therapy in the management of 1,000 patients with newly established acute lung injury in a multi-centre prospective randomised trial [2]. This 'Fluid and Catheter Treatment Trial' (FACTT) assessed 60 day mortality, fluid balance, ventilator-free days, intensive therapy unit (ITU) length of stay and complication rates. Catheter-derived haemodynamic parameters and clinical measures were used in conjunction with explicit protocols to guide fluid, inotrope and diuretic management.Mortality rates were similar in both groups (27.4% PAC and 26.3% CVC), as were the number of ventilator-free days during the first 28 days (mean, 13.2 and 13.5, respectively). Fluid balance was similar in both groups, as was the incidence and duration of any type of organ failure. ITU stay was reduced in the CVC group, although the authors do acknowledge the mere presence of a PAC in a patient may have prevented discharge from ITU to a ward, thus causing erroneous results.Complication rates for both groups were similar per catheter insertion. However, PAC patients, in whom a CVC may have been placed once haemodynamically stable, received 50% more catheters, thus increasing the total number of complications, mostly arrhythmias, in this group.Is the 'Swan' destined for extinction? Proponents of PAC will point out that the conclusion only applies to a relatively young (median age 50 years), medical ITU population and excluded the majority of the 11,511 patients screened. These proponents will favour the study by Friese and colleagues [3], who scrutinised the American National Trauma Data Bank in a retrospective database analysis to assess the role of PACs on mortality in adult trauma patients admitted to ITU over an eight year period.The 53,312 patients were initially divided into two groups: those that received a PAC as part of their management (4%) and those that did not. Subsequently, they were divided according to age, Injury Severity Score and initial base deficit.Unsurprisingly, a higher use of PACs and a greater mortalit...

The Effect of Mixing Iodinated Contrast Media and Ultrasound Contrast Agents on Subharmonic Signals

“…Therefore, a need for real-time noninvasive technique for cardiac pressure estimation has been iterated over several decades. [10][11][12][13][14] The SHAPE technique has potential to address the limitations associated with the cardiac catheterization procedure and to provide intra-cardiac pressure monitoring in an outpatient setting.…”