OD

Question 1

Features of opioid misuse

Answer 1

rhinorrhoea
needle track marks
pinpoint pupils
drowsiness
watering eyes
yawning

Question 2

management of opioid overdose

Answer 2

IV or IM naloxone

Question 3

Management of opioid dependence

Answer 3

refer to CGL if patient complies

specialist drug dependence clinics

NICE recommend methadone or buprenorphine as the first-line treatment in opioid detoxification

compliance is monitored using urinalysis

detoxification should normally last up to 4 weeks in an inpatient/residential setting and up to 12 weeks in the community

Question 4

benzodiazepines are only prescribed for

Answer 4

short period of time (2-4 weeks).

Question 5

what may potentiate the signs of benzodiazepine ?

Answer 5

Co-ingestion of alcohol and other central nervous system depressants

Question 6

benzodiazepine withdrawal syndrome. Features include

Answer 6

insomnia
irritability
anxiety
tremor

Benzodiazepines commonly cause drowsiness,
ataxia,
dysarthria and nystagmus.

Coma, hypotension, bradycardia and respiratory depression

rhabdomyolysis and hypothermia

respiratory depressant effects are more serious in patients with chronic obstructive airways diseas

Question 7

when should flumanzil not be used ?

Answer 7

At more than the minimum dose required to reverse ventilatory impairment; full reversal of CNS depression is neither necessary, nor desirable

When the risk of convulsions is high, e.g.:
- Known poisoning with a drug that causes convulsions (e.g. a tricyclic antidepressant)
- Features indicate sodium channel blocker or stimulant poisoning (wide QRS interval, tachycardia with large pupils), even if no such agent has been disclosed.

Question 8

investigations for benzodiazepine ?

Answer 8

FBC, U&Es and LFTs.
Check CK in patients with prolonged loss of consciousness.

ECG abnormalities include transient first degree and second degree block and QT prolongation

arterial/venous blood gas analysis in patients who have a reduced level of consciousness

Question 9

BNF gives advice on how to withdraw a benzodiazepine

Answer 9

The dose should be withdrawn in steps of about 1/8 (range 1/10 to 1/4) of the daily dose every fortnight.

switch patients to the equivalent dose of diazepam
reduce dose of diazepam every 2-3 weeks in steps of 2 or 2.5 mg
time needed for withdrawal can vary from 4 weeks to a year or more

Question 10

benzodiazepine OD management ?

Answer 10

Consider activated charcoal if one hour after ingestion

Flumazenil

Flumazenil, a GABA A receptor antagonist, may be used to avoid mechanical ventilation in patients who develop reduced ventilation and coma
due to the risk of seizures with flumazenil. It is generally only used with severe or iatrogenic overdoses.

Question 11

salicylate overdose leads to a mixed ?

Answer 11

respiratory alkalosis and metabolic acidosis

Question 12

Features of salicylate OD ?

Answer 12

hyperventilation (centrally stimulates respiration)
tinnitus
lethargy
sweating, pyrexia*
nausea/vomiting
hyperthermia
hyperglycaemia and hypoglycaemia
seizures

Question 13

salicylate diagnosis ?

Answer 13

bloods :
FBC, U&Es and LFTs. acid-base balance
GLUCOSE

salicylate concentration

ECG

arterial/venous blood gas

Question 14

Tx of salicylate OD ?

Answer 14

Consider activated charcoal if the patient presents within 1 hour of ingestion

CARDIAC MONITORING

Ensure hypokalaemia is corrected and urinary alkalinisation is instigated prior to intubation where possible
urinary alkalinization with intravenous sodium bicarbonate - enhances elimination of aspirin in the urine

Repeat an urgent salicylate concentration 2 hours after the initial test
consider referral to critical care for patients whose concentrations are around 500 mg/L (3.6 mmol/L) and rising, as they may deteriorate rapidly.

patients who are symptomatic or in patients with rising levels, continue to repeat salicylate concentrations every 2 hours, until concentrations have fallen below 200 mg/L and any clinical features have improved.

haemodialysis indication
serum concentration > 900mg/L
concentrations greater than 700 mg/L (5.1 mmol/L) in patients with a metabolic acidosis
metabolic acidosis resistant to treatment
acute renal failure
pulmonary oedema
seizures
coma

Question 15

what patients can be considered for observation in salicylate poisoning

Answer 15

Asymptomatic patients with normal acid-base status can be considered for discharge after observation for 6 hours following the overdose, provided their repeat plasma salicylate concentration at least 4 hours after ingestion is below 300 mg/L (2.2 mmol/L) and not rising

Question 16

how to manage hyperthermia in salicylate poisoning ?

Answer 16

Mild to moderate hyperthermia :
Mist and fan techniques
Ice packs to groin and axillae
External cooling devices.

temperature exceeds 38.5°C, urgent cooling measures:
Ice-baths
cold fluid lavage (gastric, bladder, peritoneal), intravascular cooling techniques.

Sedation (e.g. diazepam used with great caution to not compromise the ventilatory drive.

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Rapid sequence intubation with paralysis is usually warranted when the temperature is rising rapidly and is not controlled by the above measures.

If hyperkalaemia is likely, avoid suxamethonium.
sedation with a benzodiazepine infusion, is recommended in addition to cooling measures

Dantrolene may be considered where there is muscular hyperactivity