Evaluation of ventilator on lung profile of piglets (Sus scrofa) in hypovolemic shock treated with hypervolemic crystalloid resuscitation

Abstract

Aim: This study was conducted to assess the effect of ventilators on the lung profile of piglets in the hypovolemic shock before and after the excessive resuscitation of the crystalloid fluid. Materials and Methods: Five male piglets were used in this study as the models of shock, and there are four phases of treatment: Stabilization, shock of bleeding, normovolemic resuscitation, and hypervolemic resuscitation. The application of mechanical ventilation to patients who suspected of having lung injury may worsen the patient's conditions. The purpose of this study was to set the ventilator with the set of positive end-expiratory pressure (PEEP) of 5 cm H2O, the fraction of inspired oxygen (FiO2) of 0.5, and the inspiration: expiration (I: E) ratio of 1:2, which was applied from the stabilization phase. The shock induction was performed by removing the blood until the mean arterial pressure decreasing by 20% from the stabilization. The solution of NaCl 0.9% was used for the normovolemic and hypervolemic resuscitation. The parameter of observation consisted of extravascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI) on pulse contour cardiac output 2 and exhaled tidal volume (VTE), peak inspiratory pressure (PIP), and respiratory rate (RR) on ventilators. Results: EVLWI does not indicate pulmonary edema. A significant decrease in VTE without any significant alterations in EVLWI, PIP, and RR has indicated the shallow breathing in the shock condition. Therefore, the PVPI parameter cannot be used as a parameter for capillary permeability since its formulation does not reinforce the results of data in the shock condition. The set of the ventilator may prevent the increase of EVLWI, and the uses of ventilators do not worsen the patient's conditions during the crystalloid resuscitation. Conclusion: The use of mechanical ventilator as the support does not worsen the hypovolemic condition and is safe to use as long as the lung profile is not indicated to have lung injury.