What is the role of Morphine in Flash Pulmonary Edema?

We always taught that Morphine can decrease preload and can help with anxiety and  pain in acute flash pulmonary edema. But evidence does not support this Claim. Alfred Sacchetti et al showed in 1999 that Use of Morphine can increase ICU admission and increased need for intubation in pulmonary edema. In another study, Peacock WF et al. showed that Morphine was  associated with increased adverse events in acute de-compensated heart failure which includes higher mortality, needs more mechanical ventilation, prolonged hospitalisation, and more ICU admissions. Based on evidence there is really no EBM to suggest Morphine’s benefit in acute flash pulmonary edema.

Review article: lack of effect of opiates in the treatment of acute cardiogenic pulmonary oedema.

Is morphine indicated in acute pulmonary oedema

Circulation in 1976 published an article and showed that the effects of morphine on venous tone in patients with acute pulmonary edema is very minimal. morphine could pool of blood in the limbs of only 70 ml in normal subjects and 116 ml of blood in patients with acute pulmonary edema.

Cotter et al. in Current Opinion in Cardiology explained why Morphine can be harmful. Morphine can depress  central nervous system and cause respiratory. It may also cause  bradycardia and hypotension.