An older patient who tries to climb out of bed after surgery usually draws attention. Someone lying quietly, answering slowly, or turning away from conversation may draw much less. The second patient may be recovering normally. But if that behavior is new, it can also be a sign of delirium. The absence of agitation should never be mistaken for proof that attention and awareness have returned to normal.
Delirium is a sudden disturbance of attention and awareness that may fluctuate over hours or days. It is often imagined as restlessness, confusion, or agitation. Yet some patients experience hypoactive delirium: They become withdrawn, unusually inactive, slow to respond, or unable to follow a conversation. Because they make fewer demands on staff, the change may be harder to recognize.
There is a reasonable objection. People are often tired after surgery. Anesthetic medicines, opioid pain relief, poor sleep, and acute illness can affect alertness. A patient who is quiet in the recovery room does not automatically have delirium. The clinical question is whether the level of alertness and attention fits the timing of recovery, the medicines given, and the person’s usual behavior. A sudden or marked reduction in responsiveness requires prompt assessment for serious causes, whether or not delirium is suspected.
Time matters too. Reduced alertness immediately after anesthesia may have a different explanation from a new change on the following day. Neither timing nor a medication list settles the question on its own; the clinical course and examination still matter.
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This is where I think our choice of words matters. Describing a patient as “comfortable” or “settled” may tell a colleague something about pain or agitation. It says little about whether the patient is attentive. Someone can be calm and still have an acute change in mental status. Routine vital signs may be reassuring while that change goes unexplained.
A 2026 study in the Journal of the American College of Surgeons offers useful context. Researchers reviewed data on 97,886 surgical inpatients aged 75 and older. Delirium screening was recorded for 94.3 percent of patients at hospitals participating in the American College of Surgeons’ Geriatric Surgery Verification program, compared with 52.5 percent at other hospitals. The proportion of positive screens was not statistically different between the groups.
These findings show variation in screening practice. They do not tell us how often quiet delirium was missed, whether every screen was performed well, or whether more screening by itself improves outcomes. The American College of Surgeons’ accompanying report raises the concern that quiet delirium may be mistaken for fatigue. That is a clinical concern, not an outcome the study measured. Identifying delirium requires deliberate attention; we cannot assume it is consistently assessed simply because it matters clinically.
Guidance is more direct about the features to look for. The National Institute for Health and Care Excellence specifically warns that hypoactive delirium may be missed. Withdrawal, slower responses, reduced movement, and worsening concentration are reasons to assess an at-risk patient. The guidance recommends the 4AT, a brief delirium assessment, in appropriate ward settings and different validated tools in intensive care and postoperative recovery. Screening supports, but does not replace, a clinical diagnosis.
A useful first question is not just “Is this patient awake?” but “Is this how this person usually thinks and responds?” Previous observations, the preoperative assessment, and the time course can help establish a baseline. When that information is missing, uncertainty should be recorded rather than replaced with an assumption that the patient was always quiet. Families can sometimes answer that better than a clinician meeting the patient for the first time. A relative may notice that someone who normally chats easily now struggles to follow a sentence. That observation is not a diagnosis, and families should not carry the burden of monitoring. It is information worth hearing, documenting, and assessing.
The next step is clinical evaluation, not a label. Infection, medication effects, inadequate oxygenation, metabolic problems, dehydration, pain, and other acute conditions can contribute to altered mental status. Some require urgent intervention. A delirium screen is no substitute for checking for a dangerous cause of reduced responsiveness, and attributing the change to “just the anesthetic” can be equally unsafe when the course is unexpected.
Prevention also deserves attention, especially in older people at higher risk. The European Society of Anaesthesiology and Intensive Care Medicine recommends multicomponent non-drug measures. Good orientation, access to glasses or hearing aids, attention to sleep, pain relief, hydration, and appropriate mobility may all be part of an individualized plan. None is a guarantee, and the right approach depends on the patient’s medical condition.
For clinicians, the practical change is small but consequential. If a patient has become unusually quiet, record what changed, when it began, whether attention was assessed, and what needs review. At handover, “sleeping comfortably” may be insufficient if family members report an abrupt change from baseline. Delirium can fluctuate, so a single reassuring interaction does not necessarily settle the question.
I am not arguing that every quiet postoperative patient needs an extensive investigation. I am arguing against allowing the absence of noise to become the absence of concern. A withdrawn patient who cannot follow a familiar conversation deserves assessment just as an agitated patient does. After surgery, we should notice not only who calls for help, but also who has unexpectedly stopped taking part.
Girishkumar Modi is a senior specialist anesthesiologist at Sheikh Tahnoon Bin Mohammed Medical City and Tawam Hospital (SEHA) in the United Arab Emirates. His clinical practice includes regional anesthesia, trauma and orthopedic anesthesia, neuroanesthesia and spine anesthesia, obstetric anesthesia, pediatric anesthesia, perioperative medicine, and the management of complex surgical patients. He serves as faculty in an anesthesiology residency program accredited by the Accreditation Council for Graduate Medical Education International, where he contributes to resident teaching, clinical supervision, assessment, and mentorship. He also contributes to trauma-service development and multidisciplinary perioperative care.
His academic interests include perioperative physiology and pharmacology, regional anesthesia, total intravenous anesthesia, acute pain management, point-of-care coagulation and hemostasis, medical education, health care economics, and perioperative patient safety. He is active in clinical research, medical writing, and peer review, with publications spanning anesthesiology, pharmacology, perioperative medicine, regional anesthesia, point-of-care coagulation and rotational thromboelastometry, and medical education. His work has appeared in the Mathews Journal of Anesthesia, the Journal of Anesthesia & Pain Medicine, and Anaesthesia, with abstracts presented at the Association of Anaesthetists Winter Scientific Meeting in London and the Integrated Anesthesia and Comprehensive Care Conference in Abu Dhabi.
He also writes commentary on clinical judgment, artificial intelligence, and patient readiness for surgery, including rapid responses in The BMJ such as “Medicine is not a 64-square board: Human oversight requires independent judgment” and “AI systems need a tested exit plan.”
