Congenital diaphragmatic hernia (CDH) is a serious and sometimes fatal congenital diaphragmatic abnormality.
The single most significant factor for improving RV (right ventricular) failure is recognizing and anticipating it. Therefore, therapies and medications for RV failure should focus on enhancing coronary RV perfusion, optimizing pre-load, and lowering PVR (pulmonary vascular resistance).
In the management of RV failure, the first step is to augment RV pre-load to the pressure of 8-12 mmHg to improve cardiac output, reduction of RV pre-load is through ventilator parameters adjustment or by pulmonary vasodilator use as NO (nitric oxide), PDE-5 (phosphodiesterase-5 inhibitors), guanylate cyclase stimulator, and endothelin receptor antagonist.
The use of Milrinone (phosphodiesterase-3 inhibitor) improves RV contractility by increasing the concentration of intracellular cAMP, In addition to usage of vasopressin, IABP (intra-aortic balloon pump), and epinephrine as the first line of treatment for improving the mean pressure and systemic diastolic pressure.
The use of alveolar oxygen fraction (100%) and optimal ventilator parameters are practical approaches for improving myocardial oxygen delivery. In addition, the use of epicardial wires for temporary pacing and epinephrine boluses can support systemic blood pressure and heart rate. To maintain sinus rhythm, atrial-biventricular pacing or AV sequential is used.
RV Failure specific and RV dysfunction management and situations:
Intra-op RV failure:
Intraoperative strategies, hemostasis, normothermia maintenance to reduce coagulopathy, autologous priming, extracorporeal circuit use, and avoidance of excess hemodilution are required for intra-op RV failure.
Focus on the protection of RV from functional impairment (as much as possible) and limitation of RV (volume) overload are required for treating vasoplegia.
Prevention of protamine reaction includes prostacyclin, which stimulates the release of nitric oxide in return. Inhaled nitric oxide at 40 ppm is the most successful treatment for the APH.
Post heart transplant RV failure:
RV failure treatment includes IV-fluids judicious administrations, inotropic support, and a high FiO2 inhaled fraction for facilitating pulmonary vasodilation.
Post-LVAD implantation RV failure:
For post-LVAD implantation, RV failure management, inotropes, dobutamine, levosimendan, and Milrinone, can also be used. Other options can be using an ECMO (extracorporeal membrane oxygenation) circuit, which doesn’t result in the compression of the ventricles compared to the VADs.
RV failure and role of mechanical support devices:
RV is supported via the use of ECMO or RVAD. RVAD implantation can either be surgical or percutaneous, which may include a centrifugal pump and axial pump. However, ECMO decompresses the RV, helps in decreasing PA pressure, and maintains the cardiac output while preserving end-organ functions.
Congenital cardiac surgeries and RV failure:
The most common cause of cardiac failure is congenital heart disease, especially the Ebstein anomaly. For easing the implementation of treatment modality, open sternum can be beneficial in the perioperative period for patients. This process has received affirmation from the subjective clinical practice guidelines for patients who had right-sided deterioration of function during the chest closure.
In conclusion, management of RV dysfunction needs proactive strategies, including the correction of underlying causes. The first lines of therapies are ventilator adjustments, RV contractility improvement, pre/afterload optimization, and the use of inotropes for RV contractility.
Varma PK, Srimurugan B, Jose RL, Krishna N, Valooran GJ, Jayant A. Perioperative right ventricular function and dysfunction in adult cardiac surgery-focused review (part 2-management of right ventricular failure). Indian J Thorac Cardiovasc Surg. 2021 Nov 4:1-10. doi: 10.1007/s12055-021-01226-w. Epub ahead of print. PMID: 34751203; PMCID: PMC8566189.