27 Dec 06
By M Hadian and M R Pinsky
Critical Care 2006, 10(Suppl 3):S8
The pulmonary artery catheter (PAC) was introduced in 1971 for the assessment of heart function at the bedside. Since then it has generated much enthusiasm and controversy regarding the benefits and potential harms caused by this invasive form of hemodynamic monitoring. This review discusses all clinical studies conducted during the past 30 years, in intensive care unit settings or post mortem, on the impact of the PAC on outcomes and complications resulting from the procedure. Although most of the historical observational studies and randomized clinical trials also looked at PAC-related complications among their end-points, we opted to review the data under two main topics: the impact of PAC on clinical outcomes and cost-effectiveness, and the major complications related to the use of the PAC.
By D Payen and E Gayat
Critical Care 2006, 10(Suppl 3):S7
From the report by Connors and coworkers in 1996 until now, much effort has been directed at demonstrating the safety and/or effectiveness of strategies based on pulmonary artery catheter (PAC) data. Although studies have failed to demonstrate a clear benefit of PAC use, neither have any corroborated the initial report of PAC-induced mortality. With this in mind, it is important to clarify the indications for PAC, taking into account the development of new technologies to measure cardiac output and stroke volume. The present review focuses on safety and effectiveness data, with a special focus on reasonable indications for PAC use in the intensive care unit. The PAC has evolved since its initial presentation, and it now offers numerous parameters in addition to cardiac output and pressure measurement, such as mixed oxygen saturation and right ventricular ejection fraction. Because many techniques may be used to measure cardiac output, the indications for PAC use have become founded on other parameters that are useful in more specific situations, essentially involving the right circulation.
By M Ranucci
Critical Care 2006, 10(Suppl 3):S6
The use of pulmonary artery catheters (PACs) during cardiac surgery varies considerably depending on local policy, ranging from use in 5–10% of the patient population to routine application. However, as in other clinical fields, recent years have witnessed a progressive decline in PAC use. One of the reasons for this is probably the increasing use of transoesophageal echocardiograpy, even though careful analysis of the information provided by PAC and transoesophageal echocardiograpy indicates that the two tools should be considered subsidiary rather than alternatives. The principal categories of cardiac patients who can benefit from PAC monitoring are those with present and those with possible haemodynamic instability. On this basis we can identify five groups: patients with impaired left ventricular systolic function; those with impaired right ventricular systolic function; those with left ventricular diastolic dysfunction; those with an acute ventricular septal defect; and those with a left ventricular assist device. This review highlights the specific role of PAC-derived haemodynamic data for each category.
By V Caille and P Squara
Critical Care 2006, 10(Suppl 3):S4
Invasive and noninvasive monitoring facilitates clinical evaluation when resuscitating patients with complex haemodynamic disorders. If the macrocirculation is to be stable, then it must adapt to blood flow or blood flow must be optimized. The objective of flow monitoring is to assist with matching observed oxygen consumption (VO2) to pathophysiological needs. If an adequate balance cannot be maintained then dysoxia occurs. In this review we propose a simple schema for global reasoning; we discuss the limitations of VO2 and arterial oxygen delivery (DaO2) assessment; and we address concerns about increasing DaO2 to supranormal values or targeting pre-established levels of DaO2, cardiac output, or mixed venous oxygen saturation. All of these haemodynamic variables are interrelated and limited by physiological and/or pathological processes. A unique global challenge, and one that is of great prognostic interest, is to achieve rapid matching between observed and needed VO2 – no more and no less. However, measuring or calculating these two variables at the bedside remains difficult. In practice, we propose a distinction between three situations. Clinical and blood lactate clearance improvements can limit investigations in simple cases. Intermediate cases may be managed by continuous monitoring of VO2-related variables such as DaO2, cardiac output, or mixed venous oxygen saturation. In more complex cases, three methods can help to estimate the needed VO2 level: comparison with expected values from past physiological studies; analysis of the relationship between VO2 and oxygen delivery; and use of computer software to integrate the preceding two methods