The central nervous system during lung injury and mechanical ventilation: a narrative review

Abstract

Mechanical ventilation induces a number of systemic responses for which the brain plays an essential role. During the last decade, substantial evidence has emerged showing that the brain modifies pulmonary responses to physical and biological stimuli by various mechanisms, including the modulation of neuroinflammatory reflexes and the onset of abnormal breathing patterns. Afferent signals and circulating factors from injured peripheral tissues, including the lung, can induce neuronal reprogramming, potentially contributing to neurocognitive dysfunction and psychological alterations seen in critically ill patients. These impairments are ubiquitous in the presence of positive pressure ventilation. This narrative review summarises current evidence of lungebrain crosstalk in patients receiving mechanical ventilation and describes the clinical implications of this crosstalk. Further, it proposes directions for future research ranging from identifying mechanisms of multiorgan failure to mitigating long-term sequelae after critical illness.

ARDS associated acute brain injury: from the lung to the brain

“…In fact, it has been shown that critically ill patients are commonly admitted to the ICUs for MV [ 35 ]. Patient-ventilator interactions and the likelihood for developing acute lung injury is largely determined by the neural control of ventilation and the immune response, which could make patients susceptible to develop short- and long-term neuropsychological impairments, including delirium, sleep disturbances, persistent cognitive impairment, and post-traumatic stress disorder [ 36 ]. Although the interactions of the mechanically ventilated lung and CNS are complex and discussed in detail in the Pathophysiology Section, experimental and clinical studies suggest the existence of an interacting signalling.…”

“…This interacting signalling could be due to a physiological mechanism, as for example the Hering–Breuer reflex. Another possible cause could be a pathological process, such as excessive alveolar stretch and over-distension, which could lead to maladaptive responses and contribute to the observed neurocognitive impairments and psychological alterations [ 36 , 37 ].…”

Molecular mechanisms of postintensive care syndrome

“…There are several mechanisms that may lead to brain injury in critically ill patients [34]. The central nervous system (CNS) receives signals from neural afferences and circulating factors and cells.…”

Prone positioning reduces frontal and hippocampal neuronal dysfunction in a murine model of ventilator-induced lung injury

“…And, in cases of severe acute lung injury, prolonged pronepositioning has been shown to significantly decrease 28-day and 90-day mortality (5). In mechanical ventilation-induced acute lung injury (VILI), brain dysfunction of the frontal cortex and hippocampus frequently occurs and clinically manifests as delirium (6)(7)(8). Delirium concomitant with mechanical ventilation and severe acute lung injury contributes to an accelerated trajectory of long-term cognitive decline, increased mortality, and prolonged length of hospital stay (7,8).…”