Can We Optimize Long-Term Outcomes in Acute Respiratory Distress Syndrome by Targeting Normoxemia?

Abstract

Since its original description in 1967, acute respiratory distress syndrome (ARDS) has been recognized as a devastating condition associated with significant morbidity and mortality. Advances in critical care medicine and ARDS management have led to a substantial increase in the number of ARDS survivors. Longterm cognitive impairment after critical illness is a significant public health concern. ARDS survivors frequently experience long-term cognitive impairment, as well as physical impairment, psychiatric morbidity, and reduced health-related quality of life. At present, no intensive care unit-based intervention has been proven to reduce the risk of long-term cognitive impairment after ARDS. To address the urgent need to identify strategies to preserve long-term health, investigators have advocated the measurement of short-and long-term outcomes in clinical trials. Maintaining adequate oxygen delivery to preserve organ function is of vital importance in ARDS management. The optimal target range for arterial oxygenation in ARDS remains unknown, due in part to the challenge to maintain adequate tissue oxygenation and to minimize harm, such as oxygen toxicity. An approach targeted to subnormal oxygenation values (partial pressure of arterial oxygen, 55-80 mm Hg) has emerged as a means to accomplish these aims. In this perspective, we critically evaluate this strategy from short-and long-term perspectives, with a focus on the potential long-term cognitive effects of the strategy. We conclude with a proposal to consider resetting the target range for arterial oxygenation higher (85-110 mm Hg) as a potential strategy to improve the long-term outcomes of ARDS survivors.

Handling Oxygenation Targets in the Intensive Care Unit (HOT‐ICU)—Protocol for a randomised clinical trial comparing a lower vs a higher oxygenation target in adults with acute hypoxaemic respiratory failure

“…Despite this guideline being published, several questions remain unanswered. Most importantly, how will oxygenation targets of strict normoxaemia vs low normoxaemia affect short‐ and long‐term patient‐important outcomes in patients admitted to the ICU, and in those with hypoxaemic respiratory failure? The HOT‐ICU trial aims to answer these important questions.…”

What's Next After ARDS: Long-Term Outcomes

“…However, ARDS survivors can show long-term cognitive dysfunction in terms of attention, memory, mental processing speed, and executive function. 24,51 In 1999, Hopkins et al 51 found marked cognitive impairment in all 55 ARDS subjects within their cohort at hospital discharge; at 2 y, 47% of survivors showed persistent neurocognitive impairment with no improvement from 1 to 2 y. More recently, Mikkelsen et al 24 confirmed that long-term cognitive impairment, especially in executive dysfunction, was present in 55% of survivors at 1 y. Cognitive impairment was significantly associated with lower oxygenation at 1 y and with psychiatric disorder, particularly anxiety.…”

Neurologic complications during V-V extracorporeal membrane oxygenation: still counting…

“…Brain damage during Extracorporeal Life Support (ECLS) includes: neurocognitive impairment in survived patients, global brain injury and focal brain injury. Neurocognitive impairment in survivors from ARDS is of high concern, as many studies showed high rate of cognitive decline in this subset of patients (6)(7)(8). The authors, on the basis of correlation between hypoxemia and neurocognitive sequelae, hypothesized that the cerebral hypoxia might explain this phenomenon.…”