Lung and Diaphragm Damage at Varying Oxygen Levels and Ventilator Modes Pst Hemorrhagic.

摘要

Purpose: To determine 1) lung and diaphragm damage at various fractions of inspired oxygen (FIO2) with and without dopamine following hemorrhagic shock (HS), and 2) the extent of lung damage produced by administering three controlled mechanical ventilator modes following HS. Design: A quasi-experimental design using an in vivo animal model. Methods: Forty percent of the total blood volume was removed from anesthetized rats to elicit HS. Hydrogen peroxide (H2O2) and apoptosis were measured in the lung and diaphragm after 60 minutes of administration with the following FIO2s: 0.21, 0.40, 0.60, 1.00, and with the addition of dopamine [10 (micron)g/kg/min]. In another set of experiments, volume control (VC), pressure control (PC), and pressure-regulated volume control (PRVC) MV were administered post HS and lung H2O2 and apoptosis were measured. Sample: A total of 180 rats were used in experimental protocols. Analysis: Differences in lung and diaphragm H2O2 and apoptosis were analyzed using analysis of variance (ANOVA) and followed by post hoc tests. Significance was defined as P < 0.05. Findings: The optimal FIO2 to utilize following hemorrhagic shock was 0.40. Dopamine administered intravenously (10 micro g/kg/min) scavenged reactive oxygen species (ROS), thus reducing lung and diaphragm damage when higher concentrations of O2 were used. During HS, the ideal mode of controlled MV was PRVC. MitoSox Red was a potential biomarker for superoxide. Implications for Military Nursing: To reduce organ damage following HS, military nurses need to use the optimal O2 (40%) to prevent excess oxygen molecules to become dangerous free radicals. Dopamine should be administered if higher concentration of O2 is required. If controlled MV is necessary, a mixed mode of MV such as PRVC should be applied. In addition, using a biomarker such as MitoSox Red would be useful in monitoring the amount of oxidative stress in HS patients.