Ventilators Alone Aren’t Enough: Rethinking Therapy Timing in ARDS

For patients fighting acute respiratory distress syndrome, the ventilator is only the beginning of the story. Lung-protective ventilation—small tidal volumes, carefully tuned pressures—remains the cornerstone of clinical support, and decades of trials have confirmed that how a machine breathes for a patient can mean the difference between healing and harm. Yet a new review published in Intensive Care Medicine by Laveena Munshi, Gordon Rubenfeld, and Hannah Wunsch makes a pointed argument: in many cases, mechanical ventilation alone is simply not enough. Injurious patient–ventilator interactions, severe gas exchange abnormalities, and the underlying inflammatory chaos of ARDS often persist despite the best ventilator settings. That is where adjuvant therapies come in—interventions added to primary lung support to enhance its effectiveness, much as adjuvants boost vaccines or adjuvant chemotherapy strengthens surgery.

The review’s central reframing is subtle but consequential. Historically, adjuvant therapies were held back as rescue strategies, deployed only when refractory hypoxemia left clinicians with no other options. Current guidelines, by contrast, recommend applying them earlier in the disease course, reflecting the importance of minimizing stress and strain on the injured lung and potentially modulating the immune dysregulation that drives the syndrome. The authors organize commonly used adjuvants not by fashion or habit, but by the relative certainty of their utility and the frequency of their use—a taxonomy that reveals an uncomfortable truth: how often a therapy is used does not always match how well the evidence supports it.

At the top of the evidence hierarchy sits prone positioning, one of the most effective non-pharmacologic strategies for reducing mortality in moderate-to-severe ARDS. Its benefits extend well beyond improved oxygenation. Turning a patient face-down redistributes transpulmonary pressures more homogeneously across the lung, reduces overdistension of dorsal regions, recruits collapsed dependent lung tissue, and mitigates ventilator-induced lung injury. The PROSEVA trial demonstrated a substantial mortality reduction when prone positioning was applied early and for prolonged sessions in severe ARDS, and subsequent meta-analyses confirmed the benefit was greatest when it was combined with low-tidal-volume ventilation and sustained for more than sixteen hours per session. Despite this strong evidence and guideline endorsement, real-world adoption remains inconsistent, hampered by logistical demands and variability in clinician familiarity—a gap the authors describe as both common and serious.

Continuous neuromuscular blockade occupies a more contested middle ground. The physiological rationale is compelling: paralytic agents halt patient–ventilator dyssynchrony, eliminate excessively forceful spontaneous breathing efforts that can themselves injure the lung, control transpulmonary pressures, and reduce oxygen consumption. The ACURASYS trial showed improved survival and less barotrauma with a 48-hour course of early neuromuscular blockade in patients with moderate-to-severe but persistent ARDS. But the later ROSE trial, which applied the drugs slightly earlier in the disease course, found no mortality benefit. The discrepancy may reflect evolving practice—ROSE was conducted amid lighter sedation and higher PEEP, which may have blunted the incremental value of paralysis—or the fact that ACURASYS enrolled patients slightly later, enriching the study population for persistent, harder-to-treat disease. Current guidance favors short-course, targeted use, balanced against the risks of diaphragmatic inactivity and ICU-acquired weakness.

Conservative fluid management tells a different kind of story: modest evidence, near-universal adoption. Pulmonary edema worsens hypoxemia, decreases lung compliance, and amplifies ventilator-induced injury, so draining excess fluid with diuretics—or occasionally renal replacement therapy—directly supports the goals of lung-protective ventilation. The FACTT trial found that a conservative fluid strategy improved oxygenation, shortened the duration of mechanical ventilation, and reduced ICU length of stay, though it produced no mortality benefit. Even without a survival signal, the approach has become standard supportive care, fitting neatly into a broader philosophy of de-resuscitation: meticulous fluid stewardship for critically ill patients who have already received aggressive resuscitation, regardless of whether they carry an ARDS diagnosis.

Corticosteroids, meanwhile, have ridden decades of enthusiasm and disappointment. By attenuating the inflammatory cascade underlying ARDS, steroids promise reduced alveolar inflammation and less fibroproliferation. Recent trials and meta-analyses suggest early corticosteroids may shorten mechanical ventilation and ICU stays, particularly when initiated early in moderate-to-severe disease, and the COVID-19 pandemic cemented dexamethasone as standard care for severe hypoxemic viral pneumonia. Yet uncertainty persists over optimal dosing, duration, and applicability across etiologies. In late-phase ARDS, the evidence is mixed at best: an early trial of prolonged methylprednisolone in unresolving disease was followed by a larger study that failed to replicate a mortality benefit and raised a late mortality signal when treatment began more than fourteen days after ARDS onset. The authors conclude that steroids are best considered a phenotype-dependent therapy rather than a universally effective one, with trial heterogeneity likely reflecting biological differences among patients rather than absent efficacy.

Then there are the therapies that persist despite thin evidence. Inhaled pulmonary vasodilators—nitric oxide and epoprostenol—offer an elegant physiological fix for severe hypoxemia, selectively directing blood flow toward better-ventilated alveoli and reducing pulmonary vascular resistance. Studies consistently show transient oxygenation improvements, but none has demonstrated a mortality benefit, and harms such as renal dysfunction are documented. Guidelines do not recommend routine use. Nevertheless, inhaled vasodilators remain widely employed as short-term bridges to prone positioning, transfer, or escalation to extracorporeal support, and they may ease right ventricular afterload in acute cor pulmonale, though that indication has never been tested in randomized trials. Their persistence, the authors note, embodies the recurring tension between immediate physiological rescue and outcome-based evidence.

The deeper message of the review is that the right question is no longer whether an adjuvant works, but which therapy should be applied, in which patient, at what stage of disease, and to achieve which physiological objective. Timing matters as much as selection: prone positioning early and for long sessions in severe disease, neuromuscular blockade selectively when dyssynchrony and injurious breathing efforts dominate, fluids tightened once resuscitation is complete, steroids matched to inflammatory phenotype and etiology. The authors propose a framework mapping each adjuvant onto the evolving phases of ARDS, treating the syndrome as a moving target rather than a static diagnosis. Static classification at the bedside, they suggest, may ultimately matter less than dynamic reassessment throughout the illness.

Looking forward, the future of adjuvant therapy may be defined less by discovering new drugs than by deploying existing ones better. Advances in phenotyping—biological, physiological, and imaging-based—could identify which patients benefit from which interventions. The hyperinflammatory and hypoinflammatory subphenotypes described by Calfee and colleagues have already shown differential responses to several therapies, suggesting treatment effect varies with host biology rather than the syndrome label alone. Physiological phenotyping—respiratory mechanics, recruitability, respiratory drive, right ventricular function—may sharpen selection further. Equally important, the authors argue, is a willingness to de-adopt therapies lacking a strong evidence base. Adjuvants, they conclude, should not be regarded as rescue therapies of last resort but as targeted tools applied thoughtfully within a broader lung-protective strategy. The goal is deceptively simple to state and hard to achieve: the right adjuvant, for the right patient, at the right time.

Subject of Research: Adjuvant therapies for acute respiratory distress syndrome across the course of the disease

Article Title: Beyond the ventilator: deploying adjuvant therapies across the course of ARDS

Article References: Beyond the ventilator: deploying adjuvant therapies across the course of ARDS. (n.d.). https://doi.org/10.1007/s00134-026-08594-0

Image Credits: AI Generated

DOI: 10.1007/s00134-026-08594-0

Keywords: ARDS, mechanical ventilation, prone positioning, neuromuscular blockade, corticosteroids, conservative fluid management, inhaled pulmonary vasodilators, lung-protective ventilation, phenotyping, critical care, ventilator-induced lung injury, intensive care medicine