Relationship between hyperoxemia and ventilator associated pneumonia

Abstract

Previous studies suggest a relationship between hyperoxemia and ventilator-associated pneumonia (VAP). Hyperoxemia is responsible for denitrogenation phenomena, and inhibition of surfactant production, promoting atelectasis in mechanically ventilated patients. Further, hyperoxemia impairs the efficacy of alveolar macrophages to migrate, phagocyte and kill bacteria. Oxygen can also cause pulmonaryspecific toxic effect called hyperoxic acute lung injury leading to longer duration of mechanical ventilation.All these hyperoxic effects are well-known risk factors for VAP. A recent retrospective large single center study identified hyperoxemia as an independent risk factor for VAP. However, two recent randomized controlled trials evaluated the impact of conservative oxygen strategy versus a liberal strategy, but did not confirm the role of hyperoxemia in lower respiratory tract infection occurrence. In this review, we discuss animal and human studies suggesting a relationship between these two common conditions in mechanically ventilated patients and potential interventions that should be evaluated. Further large prospective studies in carefully selected groups of patients are required to confirm the potential role of hyperoxemia in VAP pathogenesis and to evaluate the impact of a conservative oxygen strategy vs. a conventional strategy on the incidence of VAP.

Observations on the perfusion recovery of regenerative angiogenesis in an ischemic limb model under hyperoxia

“…; Jaffal et al. ). Our search for a better use of this powerful instrument (O2) was primarily made using a standardized challenge procedure involving a 10 min hyperoxia challenge followed by a 10 min normoxic recovery, in which all perfusion changes were recorded in both distal limbs.…”

“…; Abman ; Jaffal et al. ) but also to a poor knowledge about the mechanisms to explain the wide variability of related responses (Abman ; Potter et al. ; Jaffal et al.…”

Phagocytosis–Inflammation Crosstalk in Sepsis: New Avenues for Therapeutic Intervention

“…All of these conditions can be a component of early sepsis syndrome and we suggest that they might be part of an evolutionary adaptation to systemic infection. Conversely, diminished phagocytosis has been reported in hypercapnia ( 105 ), hypothermia and hyperoxia ( 106 , 107 ). As a result, organ-supporting strategies in sepsis treatment could be potentially harmful, at least in the context of phagocytosis.…”

“…For example, ventilator support and efforts to increase oxygen delivery to hypoxic peripheral tissues during septic shock may lead to long-lasting hyperoxia in other tissues, especially in the lungs. The phagocytic activity of pulmonary macrophages is impaired in hyperoxic conditions ( 106 ) and long-term hyperoxia is associated with a high incidence of complicating pneumonia ( 107 ).…”

Effect of Bronchoscopy on Gas Exchange and Respiratory Mechanics in Critically Ill Patients With Atelectasis: An Observational Cohort Study

“…In critically ill patients, mechanical ventilation might cause ventilator-induced lung injury and hospital-acquired pneumonia, both conditions promote atelectasis and stagnant secretions that may worsen oxygenation and delay weaning from ventilator ( 1 , 2 ).…”