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Canadian Journal of Cardiology

Positive Pressure Ventilation in Cardiogenic Shock: Review of the Evidence and Practical Advice for Patients With Mechanical Circulatory Support

Published:December 12, 2019DOI:https://doi.org/10.1016/j.cjca.2019.11.038

      Abstract

      Cardiogenic shock (CS) is often complicated by respiratory failure, and more than 80% of patients with CS require respiratory support. Elevated filling pressures from left-ventricular (LV) dysfunction lead to alveolar pulmonary edema, which impairs both oxygenation and ventilation. The implementation of positive pressure ventilation (PPV) improves gas exchange and can improve cardiovascular hemodynamics by reducing preload and afterload of the LV, reducing mitral regurgitation and decreasing myocardial oxygen demand, all of which can help augment cardiac output and improve tissue perfusion. In right ventricular (RV) failure, however, PPV can potentially decrease preload and increase afterload, which can potentially lead to hemodynamic deterioration. Thus, a working understanding of cardiopulmonary interactions during PPV in LV and RV dominant CS states is required to safely treat this complex and high-acuity group of patients with respiratory failure. Herein, we provide a review of the published literature with a comprehensive discussion of the available evidence on the use of PPV in CS. Furthermore, we provide a practical framework for the selection of ventilator settings in patients with and without mechanical circulatory support, induction, and sedation methods, and an algorithm for liberation from PPV in patients with CS.

      Résumé

      Le choc cardiogénique (CC) est souvent compliqué par une insuffisance respiratoire et plus de 80 % des patients atteints de CC ont besoin d'une assistance respiratoire. Des pressions de remplissage élevées dues à une dysfonction du ventriculaire gauche entraînent un œdème aigu du poumon qui entrave l'oxygénation et la ventilation. La mise en place d'une ventilation en pression positive continue (VPPC) améliore les échanges gazeux et peut améliorer l'hémodynamique cardiovasculaire en réduisant la précharge et la postcharge du ventricule gauche (VG), en diminuant l'insuffisance mitrale et en réduisant la demande en oxygène du myocarde; tous ces éléments peuvent contribuer à augmenter le débit cardiaque et à améliorer la perfusion tissulaire. En cas d'insuffisance ventriculaire droite (VD), cependant, la VPPC peut potentiellement diminuer la précharge et augmenter la postcharge, ce qui peut potentiellement entraîner une détérioration hémodynamique. Par conséquent, une compréhension pratique des interactions cardio-pulmonaires pendant la VPPC en cas de CC à dominante VG ou VD est nécessaire pour traiter en toute sécurité ce groupe complexe de patients en grande détresse souffrant d’insuffisance respiratoire. Nous présentons ici une revue de la littérature déjà publiée avec une discussion exhaustive des données probantes disponibles sur l'utilisation de la VPPC en cas de CC. De plus, nous fournissons un cadre pratique pour la sélection des réglages du ventilateur chez les patients avec et sans assistance circulatoire mécanique, des méthodes d'induction et de sédation, et un algorithme pour le retrait de la VPPC chez les patients atteints de CC.
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