The CAT Study

CAT: The Catecholamine Study: A Comparison of Epinephrine and Norepinephrine in Critically Ill Patients

The CAT Study, initiated by Professor John Myburgh at St George Hospital in Sydney, was a prospective, double-blind randomised trial to compare the clinical effects of adrenaline and noradrenaline in critically ill patients with circulatory dysfunction or failure. The role of the ANZIC-RC was to analyse the data set (supported by institutional grant funding from the investigators) and to assist with the preparation of manuscripts. The CAT study results were presented at the Australian and New Zealand Intensive Care Society (ANZICS) Annual Scientific Meeting in Hobart in October 2006. In addition, the abstract submitted to the European Society of Intensive Care Medicine (ESICM) Annual Congress in 2007 was awarded the International Sepsis Forum Award for best abstract.

Findings: Two hundred and eighty patients were randomised to receive either epinephrine or norepinephrine. Median time to achieve the MAP goal was 35.1 h (interquartile range (IQR) 13.8–70.4 h) with epinephrine compared to 40.0 h (IQR 14.5–120 h) with norepinephrine (relative risk (RR) 0.88; 95% confidence interval (CI) 0.69–1.12; P = 0.26). There was no difference in the time to achieve MAP goals in the subgroups of patients with severe sepsis (n = 158; RR 0.81; 95% CI 0.59–1.12; P = 0.18) or those with acute circulatory failure (n = 192; RR 0.89; 95% CI 0.62–1.27; P = 0.49) between epinephrine and norepinephrine. Epinephrine was associated with the development of significant but transient metabolic effects that prompted the withdrawal of 18/139 (12.9%) patients from the study by attending clinicians. There was no difference in 28 and 90-day mortality.

Publications: The publications relating to this study include:

Myburgh J, Higgins A, Jovanovska A, Lipman J, Ramakrishnan N, Santamaria, J and the CAT Study Investigators. Comparison of Epinephrine and Norepinephrine in Critically Ill Patients. Intensive Care Medicine 2008; 34(12); 2226-34. (DOI 10.1007/s00134-008-1219-0)

Funding: Funding for the statistical analysis of this study was provided by the Australian and New Zealand College of Anaesthetists (ANZCA). We also acknowledge the financial contribution from participating institutions that provided substantial support from internal funds.