Highlights
- The recent R2D2-ICU randomized clinical trial found no significant difference in days alive without delirium or coma at 14 days between low-use (restrictive) and high-use (liberal) physical restraint strategies in mechanically ventilated ICU patients.
- Delirium remains highly prevalent in mechanically ventilated ICU patients and is strongly associated with poorer outcomes including prolonged ventilation and hospitalization.
- Physical restraint has been identified as an independent risk factor for delirium onset, but clinical trials suggest that restraint minimization strategies do not necessarily improve delirium or coma outcomes.
- These findings challenge assumptions regarding routine use of physical restraints and prompt a balanced approach considering patient safety, agitation, and delirium risk.
Background
Mechanical ventilation is a cornerstone therapy for critically ill patients in intensive care units (ICUs), yet it is frequently complicated by delirium—a neuropsychiatric syndrome characterized by acute cerebral dysfunction marked by inattention, fluctuation in consciousness, and cognitive disturbances. Delirium in mechanically ventilated patients is common, with prevalence estimates exceeding 50%, and is associated with extended ICU stays, increased mortality, and long-term cognitive impairment. Physical restraints, particularly wrist-straps, have historically been used to prevent self-extubation, agitation, or device removal but remain controversial due to potential negative psychosocial effects and possible influence on delirium.
Despite widespread use, the impact of physical restraints on delirium and coma-free days in ventilated patients had lacked high-quality randomized trial evidence until recently. Understanding whether restrictive or liberal restraint strategies affect delirium duration, coma incidence, self-extubation, or mortality is crucial for optimizing ICU practice and patient safety.
Key Content
Chronology and Key Studies on Physical Restraints and Delirium in ICU
Several observational studies over the last decade, including the multicenter cohort study by Pandharipande et al. (2015), have demonstrated a strong association between physical restraint use and delirium onset, with restraint use conferring nearly double the risk of delirium (hazard ratio 1.87). These investigations highlighted restraint as a modifiable factor that could potentially mitigate delirium risk if used judiciously. However, such studies were limited by confounding and the inability to establish causality.
The gold-standard evidence for causality has emerged from the 2026 R2D2-ICU randomized clinical trial conducted across 10 ICUs in France. This open-label trial enrolled 405 adult patients within 6 hours of initiating invasive mechanical ventilation expected for at least 48 hours. Patients were randomized to either a restrictive, low-use wrist-strap restraint strategy (applied only for severe agitation defined by a Richmond Agitation-Sedation Scale score ≥3) or a liberal, high-use strategy (routine application with daily reassessment).
R2D2-ICU Trial Design and Outcomes
The primary outcome was days alive without delirium or coma during the first 14 days after randomization. Secondary endpoints included incidence of self-extubation and 90-day mortality. Among 396 patients with evaluable data (median age 65 years, median SOFA score 7), the mean days alive without coma or delirium were 6.67 (95% CI, 5.69–7.65) in the low-use group vs. 6.30 (95% CI, 5.35–7.24) in the high-use group. The adjusted mean difference was 0.37 days (95% CI, -0.71 to 1.46; P=0.51), indicating no statistically significant difference. Secondary outcomes including self-extubation rates (9.2% vs. 8.5%) and 90-day mortality (37.2% vs. 41.0%) were also similar.
Contextualizing Findings with Prior Evidence
While the observational data suggested a strong link between restraint and delirium, the randomized trial does not support that a restrictive restraint strategy improves delirium or coma-free days compared to a liberal approach. The findings may reflect the complexity of delirium pathophysiology, where multiple factors such as sedation, metabolic status, infection, and inflammation interplay with restraint exposure.
Furthermore, the comparable rates of self-extubation between groups counter the concern that restrictive restraint use may increase accidental device removal risks, supporting the safety of restraint minimization when guided by agitation severity.
Expert Commentary
The negative result of the R2D2-ICU trial regarding restraint reduction and delirium-free days challenges entrenched practices of systematic physical restraint use in mechanically ventilated patients. It underscores the need for nuanced balancing of agitation control, patient autonomy, and delirium prevention strategies.
Mechanistically, restraint may contribute to patient distress and agitation potentially exacerbating delirium, but the trial suggests this effect might be offset by other clinical and environmental factors in the ICU milieu. It also highlights that physical restraint is a marker of patient severity and agitation rather than a direct cause of prolonged delirium.
Clinical guidelines increasingly emphasize nonpharmacologic delirium prevention, such as sedation minimization, early mobilization, environmental optimization, and delirium screening, over reliance on restraints. The trial findings reinforce that physical restraint strategies alone may not suffice to alter delirium outcomes.
Limitations of the trial include its open-label design and generalizability restricted to similar healthcare settings and patient populations. Further research may explore stratified approaches based on delirium phenotypes, sedation protocols, and patient preferences.
Conclusion
Recent high-quality randomized evidence demonstrates that in mechanically ventilated ICU patients, a restrictive, low-use physical restraint strategy does not significantly reduce days alive without delirium or coma at 14 days compared with a liberal, high-use strategy. Despite prior observational associations, restraint minimization alone does not translate to improved delirium outcomes.
Clinicians should integrate these findings into holistic ICU delirium management emphasizing multimodal prevention and individualized patient care while maintaining safety through vigilant monitoring and appropriate agitation control. Future investigations are warranted to delineate mechanisms linking restraint, sedation, agitation, and delirium and to refine patient-centered restraint protocols.
References
- Martin GS, ACP Journal Club Editorial Team at McMaster University. In mechanically ventilated ICU patients, low vs. high physical restraint use did not differ for days free of delirium or coma at 14 d. Ann Intern Med. 2026 Jul 7; PMID: 42407074. https://pubmed.ncbi.nlm.nih.gov/42407074/
- Rosa RG, Laswell R, Aubron C, et al. Restrictive vs Liberal Physical Restraint Strategies in Critically Ill Patients: The R2D2-ICU Randomized Clinical Trial. JAMA. 2026 Apr 14;335(14):1232-1242. doi: 10.1001/jama.2026.2897. PMID: 41841304. https://pubmed.ncbi.nlm.nih.gov/41841304/
- Pandharipande PP, Girard TD, Jackson JC, et al. Prevalence, risk factors, and outcomes of delirium in mechanically ventilated adults. Crit Care Med. 2015 Mar;43(3):557-66. doi: 10.1097/CCM.0000000000000727. PMID: 25493968. https://pubmed.ncbi.nlm.nih.gov/25493968/
