Postoperative Delirium (POD) : The Confusion After Surgery
- Yoon Shwe Yi Han
- May 4
- 2 min read
After a surgery, particularly one involving general anesthesia or an emergency procedure, a patient may wake up feeling confused, disoriented, or not quite themselves. It could be post-operative delirium (POD) , one of the most common complications following surgery especially in older adults.
Postoperative delirium (POD) can occur from 10 minutes after anesthesia to up to 7 days in the hospital or until discharge. If not identified early and managed appropriately, it can lead to serious long-term consequences, including cognitive decline, functional impairment, increased risk of physical injury, prolonged hospitalization, and even transfer to long-term care facilities.
Types of delirium and symptoms
Delirium is an acute disturbance in cognitive function, affecting thinking, memory, awareness, and focus. It is important to not be diagnosed separately from Emergence delirium - occurs 5-15 minutes after awakening from anesthesia. POD manifests in three distinct forms:
Hypoactive Delirium
It is the most common form of POD, characterised by lethargy, drowsiness, inacitivity, reduced responsiveness. It is often under-diagnosed due to subtle presentations. Due to delayed recognition, it has poor prognosis and higher mortality in comparison with other subtypes.
Hyperactive Delirium
It is characterised by restlessness, agitation, irritability, hallucinations and aggression, making it easier to get identified and diagnosed. These patients may pull at lines, attempt to get out of bed unsafely, or become combative with staff.
Mixed Delirium
This is a combination of hypoactive and hyperactive delirium, switching between the two. It usually requires more complex treatments than hyperactive or hypoactive POD alone.
Risk factors for POD
The understanding of the mechanism behind POD is currently limited but recognizing risk factors is crucial for prevention and early intervention.
Pre-operative factors
Age over 65 years
Male gender
Baseline cognitive dysfunction
Dementia
Peripheral vascular disease
Prior stroke/transient ischemic attacks
Sensory impairments
Diabetes mellitus
Hypertension
Benzodiazepine use
Alcohol abuse
Intra-operative factors
Emergency surgery
Hip surgery
Cardiac surgery
Increased Surgical duration
Hypotension
Shock
Arrhythmias
Hypothermia/hyperthermia
Blood Transfusion
Post-operative factors
Low hemoglobin
Hypoxemia (low oxygen)
Prolonged intubation
Pain
Sleep-wake disturbances
The hospitals usually use several assessments postoperatively such as Confusion Assessment Method (CAM), Delirium Symptom Interview, Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) and Intensive Care Delirium Screening Checklist either in the intensive care unit and on the ward. Regular screening ensures that even subtle cases, particularly hypoactive delirium, are identified before complications arise.
Management
Managing POD usually includes both non-pharmacological and pharmacological method, with non-drug interventions always taking priority. Hospitals use programs such as Hospital Elder Life Program (HELP) and modified HELP to reorient the patient. Regular reorientation (reminding the patient of date, time, place), socialization, daily visits from the family and familiar faces, maintaining nutrition and hydration, managing sleep-wake cycles, noise reduction, providing sensory aids and early mobilization are also helpful.
Medications are reserved for severe agitation or psychosis that poses a safety risk, and are used only after underlying causes have been addressed.
Conclusion
Raising awareness about POD is essential, not only among healthcare providers but also among families and caregivers. The more we understand that delirium is a medical emergency of the brain, the sooner we can recognize its signs and respond with compassion rather than frustration.
References
UT Southwestern Medical Center (2020) https://utswmed.org/medblog/postoperative-delirium-seniors-recognizing-symptoms-reducing-risks/
MDPI (2025) https://www.mdpi.com/1422-0067/26/23/11314
Assessed and Endorsed by the MedReport Medical Review Board
