Morphine in acute pulmonary oedema: a signal of harm but more questions than answers

Abstract

This article refers to 'Midazolam versus morphine in acute cardiogenic pulmonary oedema: results of a multicentre, open-label, randomized controlled trial' by A. Domínguez-Rodríguez et al., published in this issue on pages 1953-1962.Acute heart failure (AHF) is a clinical condition associated with high rates of short-and long-term mortality and readmission, a trend that has remained practically unchanged in the last decades. 1 Despite many clinical trials conducted to date in these patients, there is not a single approved agent that is known to alter the natural history and/or clinical outcomes of AHF. There is a large spectrum of AHF presentations resulting from the interaction between an acute precipitant, a patient's underlying cardiac condition and previous comorbidities. 2 The identification of more distinct entities would help clinicians to address the immediate life-threatening medical condition and to direct treatment strategies more correctly by targeting specific underlying conditions. 2 Acute pulmonary oedema (APO) is the second most common manifestation of AHF associated with a high-acuity presentation. 3 The clinical picture of APO is dominated by respiratory distress and hypoxaemia and immediate management goals are directed to relieve dyspnoea and to decrease pulmonary congestion. However, most of the evidence is derived from mega-trials conducted in general AHF populations, not entirely generalizable to the APO clinical profile. 4 In addition, none of the studied interventions showed simultaneous benefit for symptomatic relief and increased survival. [5][6][7] Morphine is still used in patients with APO based predominantly on its beneficial haemodynamic effects (reduction in pre-and afterload) and those on the central nervous system (improvement in patient anxiety, respiratory difficulty and chest pain). However, randomized controlled trials have not provided persuasive evidence of clinical benefit for its use in patients with APO. 8 Morphine-induced reduction in venous tone may be considered advantageous in the setting of APO, as it may result in a volume shift from central toThe opinions expressed in this article are not necessarily those of the Editors of the European Journal of Heart Failure or of the European Society of Cardiology.