History of the Pulmonary Artery Catheter

OVERVIEW

• Physiological monitoring is widely used in ICU
• Technologies vary across a spectrum of risk and cost
• Uptake of technology largely driven by technological innovation rather than efficacy or cost-effectiveness (there is not even any good evidence that pulse oximetry affects patient outcomes)
• The history of the pulmonary artery catheter (PAC) typifies this

HISTORY OF THE PAC

Development, and widespread adoption, of the PAC…

• 1929 – Werner Forssman – right atrial catheterisation (on himself);
• 1945 – Cournand and Richards 1945 — Cardiac output measurement by direct Fick method.
• 1956 – Forssmann, Cournand and Richards jointly won the Nobel Prize in Medicine
• 1970 – Swan and Ganz – PAC monitoring of right heart pressures
• 1972 – Forrester — thermister added to PAC allowing CO measurement by thermodilution
• 1975 – Stephen Streat assists with first PAC used in New Zealand ☺
• 1970s and 1980s – PAC use becomes widespread due to ‘obvious’ utility of the hemodynamic parameters provided

Early clinical trials lead to controversy…

• Robin 1985 — challenged the cult of the PAC, arguing that it’s use has become epidemic without any evidence — called for clinical trials
• Shoemaker 1988 — small unblinded study (n=61) showed improved hospital mortality in high risk surgical patients with PAC used peri-operatively to target maximal oxygen delivery, versus no PAC
• Boyd 1993 — another study on high-risk surgical patients, using dopexamine to improve O2 delivery in patients with PACs, stopped early due to improved 28 day mortality
• Heyland 1996 — RR 0.86 for 1068 patients in 7 small RCTs (strongly weighted by the Shoemaker and Boyd); concluded that supra-maximal O2 delivery should not be given to unselected patients
• Connors 1996 — non-randomised case-control study of 5735 ICU patients matched by disease and propensity score — 2184 had a PAC, which was associated with increased mortality (OR 1.24)
• PAC Consensus Conference 1997 — SCCM meeting concluded that benefit of PAC was uncertain and that further RCTs were ethically justifiable
• Vincent 1998 — argued that PACs are commonly misused, that a moratorium is not necessary, that RCTs of PAC use in heterogeneous populations will not be helpful
• Sandham 1998 — argued that PAC use has been driven by the rationale of physiological measurement rather than hard data on the potential benefits, costs and harms

PAC is subjected to large scale RCTs…

• Sandham 2003 CCCCTG trial — n=1994, Phase III RCT, high-risk elderly surgical patients, no difference in hospital, 6 month or 1 year mortality with pre-operative PAC and goal-directed therapy; adverse events were uncommon but more PE in the PE group (8 versus 0)
• Brannay 2005 (CHF patients), Rhodes 2002 and Harvey 2005 (General ICU patients), richard 2003 (Shock and/or ARDS patients), ARDSnet 2006 (ALI patients) — none of these 5 RCTs, n=3351 patients in total, showed any advantage to PAC use in a variety of clinical settings

Metainflation occurs…

• according to Jack Cade, ‘metainflation’ is the state where the number of meta-analyses appears to exceed the number of RCTs on a given topic
• Shah 2005 — 13 RCTs, n= 5026, no difference in mortality
• Cochrane Systematic Review 2006 — 12 RCTs, n= 4686, no difference in mortality/ ICU LOS/ hospital LOS

The present…

• Harvey 2006 — review of 11 RCTs including PACMAN: “regardless of populations studies or inclusion of additional interventions, there was no improvement in patient outcomes as a result of management with a PAC”
• Stephen Streat in 2007 was part of a consensus decision to remove the PAC from DCC in Auckland, without replacement by another form of cardiac output monitoring
• yet the market for PAC is only slowly decreasing, with a marked rise in other forms of cardiac output monitoring devices that are replacing the PAC
• Guergel 2011 — meta-analysis of 32 RCTs, n= 5056, goal-directed therapy using cardiac output monitoring in high-risk surgical patients without organ dysfunction may improve mortality and risk of organ dysfunction (mortality weighted by earlier, poorer quality studies; but organ effects were robust)

References and Links

• CCC — Pulmonary Artery Catheter (PAC) – Literature Summaries
• Swan HJ, Ganz W, Forrester J, Marcus H, Diamond G, Chonette D. Catheterization of the heart in man with use of a flow-directed balloon-tipped catheter. N Engl J Med. 1970 Aug 27;283(9):447-51.
• Chatterjee K. The Swan-Ganz catheters: past, present, and future. A viewpoint. Circulation. 2009 Jan 6;119(1):147-52.
• Forrester JS, Ganz W, Diamond G, McHugh T, Chonette DW, Swan HJ. Thermodilution cardiac output determination with a single flow-directed catheter. Am Heart J. 1972 Mar;83(3):306-11
• Robin ED. The cult of the Swan-Ganz catheter. Overuse and abuse of pulmonary flow catheters. Ann Intern Med. 1985 Sep;103(3):445-9.

Eponymictionary

• Eponymictionary, Werner Theodore Otto Forßman (1904 – 1979)
• Eponymictionary, André Frédéric Cournand (1895 – 1988)
• Eponymictionary, Dickinson Woodruff Richards, Jr. (1895 – 1973)
• Eponymictionary, Harold James Charles ‘Jeremy’ Swan (1922 – 2005) 
• Eponymictionary, William Ganz (1919 – 2009)

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