Authors: Chen C et al.
Journal of Clinical Anesthesia, 2026, 10.1016/j.jclinane.2026.112123
This multicenter prospective cohort study examined whether untreated preoperative sleep disturbance independently increases the risk of perioperative neurocognitive disorders (PND) in older adults undergoing major non-cardiac surgery.
A total of 535 patients aged ≥60 years undergoing surgery lasting ≥2 hours were enrolled between June 2024 and May 2025. Patients were stratified by Pittsburgh Sleep Quality Index (PSQI):
• Sleep disturbance (SD): PSQI >7 (n=288)
• No sleep disturbance: PSQI ≤7 (n=247)
The primary outcome was postoperative cognitive dysfunction (POCD) assessed at postoperative days 7, 30, 90, and 180. Secondary outcomes included:
• Postoperative delirium (POD) during days 1–3
• Quality of recovery (QoR-15)
• Insomnia severity at 30, 90, and 180 days
Key Findings
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Postoperative Cognitive Dysfunction
Sleep disturbance significantly increased POCD risk at all time points:
• Day 7: 41.7% vs 27.1% (RR 1.44; P < 0.001)
• Day 30: 36.1% vs 18.2% (RR 1.73; P < 0.001)
• Day 90: 25.7% vs 13.0% (RR 1.66; P < 0.001)
• Day 180: 19.4% vs 8.9% (RR 1.75; P < 0.001)
The risk elevation persisted up to 6 months postoperatively.
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Postoperative Delirium
• POD occurred in 29.9% of SD patients vs 18.6% of non-SD patients (RR 1.43; P = 0.006)
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Quality of Recovery
• SD patients had significantly worse QoR-15 scores (mean difference 8 points; P < 0.001)
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Persistent Insomnia
• At 180 days: 34.7% of SD patients still had insomnia vs 13.8% without SD (P < 0.001)
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Risk Prediction Threshold
A PSQI ≥10 optimally predicted POCD:
• Sensitivity 71.8%
• Specificity 69.4%
Interpretation
This study strongly suggests that untreated preoperative sleep disturbance is not simply a benign symptom but an independent predictor of both early delirium and longer-term cognitive dysfunction.
The persistence of elevated POCD risk through 180 days is particularly striking. This supports a sustained cognitive vulnerability rather than transient early postoperative confusion alone.
The findings are biologically plausible. Sleep disturbance is associated with:
• Neuroinflammation
• Impaired glymphatic clearance
• Reduced cognitive reserve
• Increased sympathetic tone
• Altered stress response
All of these mechanisms may amplify vulnerability to anesthetic and surgical stress.
Clinical Implications
Screening older adults for sleep disturbance preoperatively using PSQI is simple and low-cost.
A PSQI ≥10 appears to identify a higher-risk phenotype.
Potential intervention strategies may include:
• Preoperative sleep hygiene counseling
• Cognitive behavioral therapy for insomnia (CBT-I)
• Melatonin-based interventions
• Avoidance of sedative-hypnotics when possible
• Enhanced postoperative sleep optimization
Importantly, this study was observational, so causation cannot be proven. However, the magnitude and persistence of associations support sleep disturbance as a modifiable risk factor.
Key Points
• Preoperative sleep disturbance independently predicts POD and POCD.
• Risk remains elevated up to 6 months postoperatively.
• PSQI ≥10 identifies high-risk patients.
• Sleep disturbance is associated with poorer recovery and persistent insomnia.
• Preoperative sleep optimization may reduce cognitive decline in older adults.
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