Confusion and Sedation

Acute Confusional States
and Sedation

Contributing Causes

Acute confusion is very common post-operatively
- stress, eg fatigue, fear, anxietym pain, abnormal sleep pattern
- systemic disease, eg SIRS, organ failure, infections eg UTI, thyroid disorders, electrolytes, alcohol withdrawl, vitamin deficits.
- intracerebral causes, eg CVAs, postictal, head injury, infections, tumours.
- drugs eg hypnotics, opioids, tricyclics, dopamine agents, digoxin, b-blockers, steroids, nsaids, diuretics.

General Management
- the aim is to identify and treat the cause
- often this is required so that treatment, eg O2 can be given.

1. Keep person oriented
- calm, quiet environment
- clocks, calendars, personal effects, windows, regular sleep periods
- be empathetic, explanations are unlikely to work.

2. Search for causes
- examine ABCs
- review notes, take a history, ask ward staff
- thorough clinical examination
- blood tests, ABG, CT, ECG etc as required

3. Sedation
- put up the bed rails
- remember no sedative technique is fully safe, titrate carefully
- begin a sedation flow sheet eg Ramsay sedation score below
- regularly monitor resps, HR, BP, sats (but think of hypercapnia also)

Ramsey Sedation Score
1. Anxious / restless / agitated
2. Coooperative oriented and tranquil
3. Quiet, responds
4. Asleep, brisk response to loud stimulus / forehead tap
5. Asleep, sluggish response to above
6. Unresponsive

Drugs used in sedation
- broadly hypnotics/anxiolytics and antipsychotics
- use in small aliquots titrated to effect
- be careful in very ill, elderly, or hepatic/renally impaired

Benzodiazepines
Augment GABA (inhibitory neurotransmitter)
- opens Cl- channels, reducing neuronal excitability
- well absorbed orally, can also go via IM/IV
- metabolised in liver, half life varies (diazepam long c/w midazolam)
- alone do not cause resp depression, but synergistic with opioids
Eg Diazepam 2mg tds po, 2.5-10mg IV, 2.5-10mg IM
Eg Midazolam 2.5-10mg IV

Trichloroethanol
Eg chloral hydrate and triclofos
- metabolised rapidly in liver to sedative trichloroethanol
- eg chloral hydrate 500mg-2g po
- eg triclofos oral 500mg-2g

Phenothiazines
Block many neurotransmitters eg dopamine, catecholamines, histamine, acetylcholine, 5-HT.
Produce apathy and reduced initiative
- but also postural hypotension, obstructive jaundice, autonomic effects, hypothermia and expyramidals.
- can cause neuroleptic malignant syndrome
- variable relationship between levels and effect, and are variable absorbed.
- eg chlorpromazine 25-50mg pr tds, to 300mg daily (1/3 in elderly); or IM 25-50mg tds

Butyrophenones
Block many neurotransmitters, eg dopamine, alpha-adrenergics, muscarinic and 5-HT.
- may cause hypotension, extrapyramidal effects, neuroleptic malignant syndrome
- eg Haloperidol (very useful in the agitated pt with few resp side effects)
- po 1.5-3mg tds-qid, max 15mg daily (1/2 these doses in the elderly)
- im 2-30mg tds-qid
- iv 1-5mg

Chlormethiazole
Like thiamine, used for alcohol withdrawal.
IV contains only 32mmol/L Na+, so beware hyponatraemia in high dose administration
PO dose is 250-500mg
Use 3-7.5ml/min until light sleep induced, then maintenance 0.5-1ml/min
- monitor Ramsey Score.

Treating overdose
Ensure airway
Place in recovery position
High flow O2 (facemask 15l/min)
Ventilatory support
Call for support
Administer antagonist eg flumazenil for benzos.

Alcohol Withdrawal

Symptoms start within 24hrs
Shaking, sweating, anxiety, agitation, confusion.
- progress to hypertension, tachypnoea, hallucinations and siezures
Chlordiazepoxide is recommended by CCrISP as reducing symptoms, preventing siezures and delirium tremens (may be IV).
Don't forget IM/IV vitamins B and C
Treat seizures with anticonvulsants