Question 17

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

Price, Laura C., et al. "Pulmonary vascular and right ventricular dysfunction in adult critical care: current and emerging options for management: a systematic literature review." Crit Care 14.5 (2010): R169.

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