Postoperative delirium (POD)

Delirium is a mental state in which someone is disoriented, confused and not able to think or remember clearly. Delirium usually starts suddenly. 

Postoperative delirium can occur during recovery from anesthesia or a few days after surgery. The overall incidence of POD is 5-50%. It occurs more frequently in the elderly orthopedic patients and those undergoing emergency surgical procedures.

Types of Delirium 

*There are two types of delirium*

*Hyperactive* (restlessness, incoherent speech,agitation, hallucinations)

*Hypoactive* (withdrawn, poorly responsive to the environment, depressed).

What are Preoperative risk factors for POD? 

There are many factors that increases the risk of POD. They are listed here. 

1) Pre-existing cognitive impairment

2) Dementia 

3) Frailty

4) Parkinson's disease

5) Severe illness

6) Renal impairment and depression.

What are the Precipitating factors for post operative delirium? 

These include

1. Surgery. 

2. Intraoperative use of opioids and benzodiazepines. 

3. Change of medications. 

4. Electrolyte and fluid abnormalities.

5. Constipation. 

6. Catheterization and 

7. An unfamiliar environment.

Management. 

Management aims to reduce the impact and duration of delirium as follows

1) Correction of reversible cause. 

2) Involvement of relatives or friends whom the patient knows

3) Pain controle. 

4) Haloperidol, an anti-psychotic drug, is the last option.

Causes of Delirium

There are many causes of Delirium including renal, cardiovascular, respiratory. It's also associated with certain drugs. Most of the causes listed in the table below 

Question (MCQ) 

Now at the end we will solve a question 

Which of the following can be a possible cause of acute confusional state 30 minutes after emergency surgery in a 73 year old patient?

A) Hyponatremia

B) Administration of halothane for induction of general ansthesia

C) Administration of nitrous oxide for induction of general anesthesia

D) Hyperkalemia. 

E) None of the above

Correct: A (Hyponatremia)

The diagnosis is post operative delirium(POD) and cause is the hyponatremia.