Outline the advantages and limitations of the various therapeutic options available for the treatment of right ventricular dysfunction.

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College Answer

Therapy

Advantages

Disadvantages

Volume

Effective, as RV needs a
higher filling pressure. A PA catheter may be useful in guiding volume therapy.

Determination of preload
is problematic, RA pressure may be high in chronic right heart failure and may not be a predictor of volume response. Functional parameters of volume responsiveness not useful in right heart failure

Inotropes and vasopressors

-May be of benefit in RV
infarction where they may increase coronary perfusion pressure
- Some suggestion that levosimendan may improve RV afterload in ARDS

No large scale published
data on any specific inotrope or pressor in isolated RV failure

Afterload manipulation
- Control of hypoxia and hypercapnia and acidosis

reduce PA pressures

Optimal target levels unclear.

Prostaglandins

Reduce pulmonary
pressures

May cause systemic
hypotension, flushing

NO

Improves VQ matching,
improves oxygenation

Met Hb, platelet
dysfunction, requires special delivery systems, not shown to improve mortality

Bosentan

Reduce pulmonary
pressures

No large scale data

Phosphodiesterase
inhibitors - sildefanil

Reduce pulmonary
pressures

No large scale data

Pacing to improve A-V
synchrony

Improves preload

Mechanical ventilation

May improve oxygenation
and CO2 transfer and may reduce pulmonary hypertension

Deleterious effects of
IPPV

Discussion

This paper was issued to candidates late in 2009. A pity, because an excellent article on this topic came out in Critical Care in 2010.

I will summarise the suggestions made therein.

Volume management: a weak recommendation to closely monitor the effects of fluid challenge (seeing as conventional methods of assessing fluid responsiveness are quite useless in RV failure)

Afterload management: a weak recommendation to use noradrenaline and vasopressin, because they will only affect pulmonary arteries in very high doses.

Contractility enhancement: milrinone earns a strong promotion, but dobutamine and levosimendan only merit a lukewarm recommendation for lack of good quality evidence.

Afterload reduction: the authors strongly suggest that inhaled pulmonary vasodilators are used, rather than the IV forms. Inhaled NO and prostaglandin are strongly promoted, but oral sildenafil only gets a weak recommendation.

Bosentan and pacing are not mentioned. Mechanical ventilation is promoted as a means of avoiding atelectasis and hypoxic vasoconstriction.

 

References