Postoperative "Confusion"


Postoperative confusion is common after major surgery, particularly cardiothoracic surgery, where elderly patients with comorbidity undergo intense monitoring postop. It is a serious situation which is dangerous to the patient (high adrenergic output particularly dangerous post CABG) and staff. It is nurse and doctor intensive. It is distressing to all concerned. The patient often remembers the details and suffers acute embarrassment at a later stage when the situation has been overcome.


  1. Hypoxia is the most significant and potentially dangerous cause but fortunately is also one of the less common causes. It does need to be excluded early in the assessment.

  2. Anaesthetic drugs

  3. Narcotics and intermediate, agonist/antagonist, narcotic analgesics e.g. Tramadol

  4. Pain

  5. Monitoring - constant bleeps and alarms

  6. Sleep deprivation - due to intensive care/HDU

  7. Drug withdrawal

    1. Alcohol withdrawal

    2. Sedative withdrawal

    3. Nicotine withdrawal

  8. Cerebrovascular disease

  9. Atrial fibrillation - on its own may make patoients uncomfortable and "dizzy"

  10. Infamiliarity with ward environs

  11. Urinary retention

The sequence often follows a pattern:

  1. the patient refuses to take medication

  2. he then expresses paranoid ideas about staff attempting to poison him

  3. starts to pull out lines

  4. forcibly tries to discharge himself

Patients can have almost super-human strength once they have developed an acute paranoid state aan restraint only makes the situation worse.


The best time to treat is at the first signs of refusal. It is imperative to treat before they pull out their IV line as it will be impossible to replace one.

  1. Treat the underlying cause - oxygen, bladder catheterisation, pain etc

  2. Non-drug interventions are useful but do not rely on them alone

    1. turn on lights

    2. talk to patient and re-assure them ("Yes I know that nurse in red is the devil incarnate but I can deal with that!")

    3. disconnect as many non-essential monitors and lines -this may include the ECG monitor and pulse oximeter till the emergency has passed.

    4. involve family but explain the situation to them. They can provide a lot of the support and re-assurance.

    5. If otherwise stable move to a separate room for the sake of themselves and other patients.

  3. Drugs

    1. Avoid Benzodiazepines if possible in this sitaution. If you must use them have Anexate available.

    2. Haloperidol is a good drug which will induce sleep but will not depress respiration. A dose of 5, 10 or 20mg may be required IVI depending on the size of the patient and the degree of agitation. There will be some hypotension once the patient is asleep.

    3. A good sleep will usually solve the problem. However, an IV dose can wear off before the patient has had a good chance to sleep it off. Therefore any one getting an IV dose should also have a dose IMI or orally to maintain the action. It is worth continuing 10mg bd (or 10mg mane, 20mg nocte) for a few days to prevent further recurrence of the confused behaviour.