Aadrenaline will generally quickly worsen heart failure because
- it massively increases peripheral vascular resistance and thus after-load on the heart.
- It significantly increases myocardial oxygen demand and in heart failure due to ischaemic heart disease this can quickly lead to myocardial infarction.
Do the effects of epinephrine not last long enough
The effects of epinephrine are indeed short but so are most ionotropic drugs - this is irrelevant however since if it were to be used in surgery it would be given via continuous infusion or repeated iv bolus doses.
... or have potentially harmful effects in larger quantities?
It has potentially harmful effects even in small quantities in heart failure.
Is it that the patient's blood flow is also increased when using epinephrine, making blood loss more significant?
The exact opposite. A major function of epinephrine in the body is to minimize blood loss in the case of trauma by inducing profound peripheral vasoconstriction. This is why for example it is often used topically to treat acute epistaxis (nose bleeds). So while it does under normal circumstances increase cardiac output it would be incorrect to say it "increases blood flow".
Although epinephrine does have important uses in surgery (to treat for example low blood pressure in the setting of bradycardia) there are generally more effective alternative drugs when it comes to heart failure (dobutamine for example).
The blocking of adrenaline is in fact a cornerstone in the treatment of heart failure which is why beta-blockers (i.e beta-adrenergic receptor blockers) are usually prescribed to patients with heart failure.