Poisoning, Emergency Treatment Flashcards
How should patients who have features of poisoning be managed?
Generally with hospital admission
- Patients who have taken poisons with delayed action should also be admitted, even if they appear well
Which drugs in overdose have a delayed onset of action? (5)
- Aspirin
- Iron
- Paracetamol
- TCAs
- Co-phenotype (diphenoxylate and atropine)
*the effects of modified-release preparations are also delayed
(And others)
It is often impossible to establish with certainty the identity of the poison and the size of the dose. This is not usually important because __________________
only a few poisons (such as opioids, paracetamol, and iron) have specific antidotes
*In most patients, treatment is directed at managing symptoms as they arise
It is often impossible to establish with certainty the identity of the poison and the size of the dose. This is not usually important because only a few poisons (such as opioids, paracetamol, and iron) have specific antidotes; few patients require active removal of the poison. In most patients, treatment is directed ___________________
at managing symptoms as they arise
- Nevertheless, knowledge of the type and timing of poisoning can help in anticipating the course of events.
All relevant information should be sought from the poisoned individual and from carers or parents. However, such information should be interpreted with care because __________________
it may not be complete or entirely reliable
_______________ is often impaired in unconscious patients.
Respiration; An obstructed airway requires immediate attention
In the absence of trauma, the airway should be opened with simple measures such as _______________
chin lift or jaw thrust
An oropharyngeal or nasopharyngeal airway may be useful in patients with reduced consciousness to prevent obstruction, provided ______________ is adequate
ventilation
An ______________ or _______________ airway may be useful in patients with reduced consciousness to prevent obstruction, provided ventilation is adequate
oropharyngeal
nasopharyngeal
Intubation and ventilation should be considered in patients whose ________________ or who have _____________________
respiratory acidosis because of inadequate ventilation
airway cannot be protected
*such patients should be monitored in a critical care area
Most poisons that impair consciousness also depress ________________
respiration; Assisted ventilation (either mouth-to-mouth or using a bag-valve-mask device) may be needed
True or False: Oxygen administration alone is sufficient in patients with compromised ventilation
FALSE: Oxygen is not a substitute for adequate ventilation, although it should be given in the highest concentration possible in poisoning with carbon monoxide and irritant gases
Oxygen is not a substitute for adequate ventilation, although it should be given in the highest concentration possible in poisoning with ___________________ and ________________
carbon monoxide
irritant gases
________________ is common in severe poisoning with central nervous system depressants
Hypotension
A systolic blood pressure of less than _______ mmHg may lead to irreversible brain damage or renal tubular necrosis.
70
A systolic blood pressure of less than 70 mmHg may lead to irreversible _______________ or ________________.
brain damage
renal tubular necrosis
What are the initial measures for correcting hypotension? (2)
- Raising the foot of the bed
- Administration of NaCl or a colloid
- Vasoconstrictor sympathomimetics are rarely required
True of False: vasoconstrictor sympathomimetics are first line in the treatment of poisoning-related hypotension
FALSE: Vasoconstrictor sympathomimetics are rarely required; conservative measures are usually sufficient (raising foot of bed and administering fluids)
Fluid depletion without hypotension is common after _____________ and after ____________ poisoning due to vomiting, sweating, and hyperpnoea.
prolonged coma
aspirin
_________________ without _______________ is common after prolonged coma and after aspirin poisoning due to vomiting, sweating, and hyperpnoea.
Fluid depletion
hypotension
Hypertension, often transient, occurs less frequently than hypotension in poisoning; it may be associated with sympathomimetic drugs such as ______________, _______________, and ______________
amfetamines
phencyclidine
cocaine
Cardiac conduction defects and arrhythmias can occur in acute poisoning, notably with ________________, some _______________, and some ________________
tricyclic antidepressants
antipsychotics
antihistamines
How are poisoning-associated arrhythmias corrected? (2)
- Correction of underlying hypoxia, acidosis, or other biochemical abnormalities
- Ventricular arrhythmias that cause serious hypotension require treatment
*If the QT interval is prolonged, specialist advice should be sought because the use of some anti-arrhythmic drugs may be inappropriate
True or False: Supraventricular arrhythmias are seldom life-threatening and drug treatment is best withheld until the patient reaches hospital
True
__________________ may develop in patients of any age who have been deeply unconscious for some hours, particularly following overdose with barbiturates or phenothiazines
Hypothermia
Hypothermia may develop in patients of any age who have been deeply unconscious for some hours, particularly following overdose with __________________ or ________________
barbiturates
phenothiazines
Hypothermia may be missed unless core temperature is measured using a ___________________ or by some other means
low-reading rectal thermometer
How should hypothermia be managed?
Prevention of further heat loss and appropriate re-warming as clinically indicated
_______________ can develop in patients taking CNS stimulants; children and the elderly are also at risk when taking therapeutic doses of drugs with antimuscarinic properties
Hyperthermia
Hyperthermia can develop in patients taking ______________; children and the elderly are also at risk when taking therapeutic doses of drugs with antimuscarinic properties
CNS stimulants
What is the initial management of hyperthermia?
- Remove all unnecessary clothing
- Use a fan
- Sponge with tepid water to promote evaporation
Sponging with ____________ (temperature) water will promote evaporation
tepid
Advice should be sought from the National Poisons Information Service on the management of severe hyperthermia resulting from conditions such as the _________________
serotonin syndrome
Both hypothermia and hyperthermia require ___________________ for assessment and supportive treatment
urgent hospitalisation
What is the management of single short-lived convulsions (lasting less than 5 min) associated with poisoning?
No treatment required
If poisoning-associated convulsions are protracted or recur frequently, _______________ or ________________ should be given by slow intravenous injection into a large vein
lorazepam
diazepam (preferably as emulsion)
True or False: Benzodiazepines can be given IM for the treatment of convulsions
False; benzos should not be given IM for convulsions
If the intravenous route is not readily available for administration of benzodiazepines in the treatment of convulsions, _________________ can be given by the ________________ route or _______________ can be administered as a _______________ solution
midazolam oromucosal solution [unlicensed use in adults and children under 3 months]
buccal
diazepam
rectal
Drug- or chemical-induced methaemoglobinaemia should be treated with ________________ if the methaemoglobin concentration is 30% or higher, or if symptoms of tissue hypoxia are present despite oxygen therapy
methylthioninium chloride
Drug- or chemical-induced _________________ should be treated with methylthioninium chloride if the methaemoglobin concentration is 30% or higher, or if symptoms of tissue hypoxia are present despite oxygen therapy
methaemoglobinaemia
What is methemoglobinemia?
Blood disorder in which an abnormal amount of methemoglobin is produced; methemoglobin is the oxidized form of hemoglobin (Fe3+) which cannot readily bind oxygen and therefore cannot transport it to tissues
Which drugs can cause methemoglobinemia? (4)
- Dapsone
- Local anesthetics
- Phenacetin (anesthetic/anti-pyretic)
- Antimalarials
(And others)
What is the mechanism of action of methylthioninium chloride in the treatment of methemoglobinemia?
Reduces ferric iron (Fe3+) of methemoglobin back to ferrous iron of hemoglobin (Fe2+)
*in high doses, methylthioninium chloride can itself cause methaemoglobinaemia
In high doses, methylthioninium chloride can itself cause ________________
methaemoglobinaemia
Given by mouth, ______________, activated can bind many poisons in the gastro-intestinal system, thereby reducing their absorption
charcoal
The sooner activated charcoal is given the more effective it is, but it may still be effective up to ____________ after ingestion of the poison—longer in the case of modified-release preparations or of drugs with antimuscarinic (anticholinergic) properties
1 hour
Activated charcoal is particularly useful for the prevention of absorption of poisons that are ________________, such as antidepressants
toxic in small amounts
Activated charcoal should be prescribed with caution in which patients? (3)
- Comatose patients (risk of aspiration)
- Drowsy patients (“ “)
- Reduced GI motility (risk of obstruction)
What are the side effects of activated charcoal? (4)
- Bezoar
- Constipation
- Diarrhea
- GI disorders
What is a bezoar?
Collection of partially digested material that collects in the stomach; sometimes the material is not digested at all and tightly packs itself into the digestive tract causing a blockage in the stomach or intestines
*human equivalent of a hairball hehe
Repeated doses of charcoal, activated by mouth enhance the elimination of some drugs after they have been absorbed; repeated doses are given after overdosage with … (5)
- Carbamazepine
- Dapsone
- Phenobarbital
- Quinine
- Theophylline
If vomiting occurs after dosing with activated charcoal it should be treated (e.g. with an antiemetic drug) since it ________________
may reduce the efficacy of charcoal treatment
- In cases of intolerance, the dose may be reduced and the frequency increased but this may compromise efficacy.
Charcoal, activated should not be used for poisoning with which substances? (6)
- petroleum distillates
- corrosive substances
- alcohols
- malathion
- cyanides
- metal salts including iron and lithium salts
Hemodialysis may be used in the treatment of poisoning with which substances? (6)
- Ethylene glycol
- Lithium
- Methanol
- Phenobarbital
- Salicylates
- Sodium valproate
Alkalization of urine with sodium bicarbonate may be useful in the treatment of _____________ poisoning
Salicylate
Alkalization of urine with __________________ may be useful in the treatment of salicylate poisoning
IV sodium bicarbonate (enhances urinary elimination)
What are the indications for hemodialysis in salicylate overdose? (6)
- Serum concentration > 700 mg/L
- Metabolic acidosis resistant to treatment
- Acute renal failure
- Pulmonary edema
- Seizures
- Coma
What is the mechanism of poisoning with salicylate overdose?
salicylates cause the uncoupling of oxidative phosphorylation leading to decreased adenosine triphosphate production (ATP), increased oxygen consumption and increased carbon dioxide and heat production
Lithium has a very narrow therapeutic range ( ________ mmol/L) and a long plasma half-life being excreted primarily by the kidneys. Lithium toxicity generally occurs following concentrations > ________ mmol/L.
- 4-1.0
1. 5
What are the methods of removal of drugs for the GI tract? (2)
- Gastric lavage
- Whole bowel irrigation (by means of bowel cleansing preparation)
Induction of emesis is NOT recommended
Gastric lavage is rarely required and should only be carried out if ________________
The airway can be protected adequately
For substances that cannot be removed effectively by other means (e.g. iron), gastric lavage should be considered only if _______________ within the previous _______________
a life-threatening amount has been ingested
hour
Gastric lavage is contra-indicated if a ______________ substance or a ______________ has been ingested, but it may occasionally be considered in patients who have ingested drugs that are not adsorbed by charcoal, such as iron or lithium
corrosive
petroleum distillate
Gastric lavage is contra-indicated if a corrosive substance or a petroleum distillate has been ingested, but it may occasionally be considered in patients who have ingested drugs that are not adsorbed by charcoal, such as ______________ or ______________
iron
_________________ (e.g. with ipecacuanha) is not recommended because there is no evidence that it affects absorption and it may increase the risk of aspiration
Induction of emesis
Induction of emesis (e.g. with ipecacuanha) is not recommended because ________________ and it may _________________
there is no evidence that it affects absorption
increase the risk of aspiration
How is whole bowel irrigation achieved?
By means of a bowel cleansing preparation
Whole bowel irrigation (by means of a bowel cleansing preparation) has been used in poisoning with certain _______________ or ______________ formulations, in severe poisoning with _____________ and _____________, and if ______________ (‘body-packing’)
modified-release
enteric-coated
iron
lithium salts
illicit drugs are carried in the gastro-intestinal tract
- However, it is not clear that the procedure improves outcome and advice should be sought from the National Poisons Information Service
Acute intoxication with alcohol (ethanol) is common in adults but also occurs in children. The features include ataxia, dysarthria, nystagmus, and drowsiness, which may progress to ____________, with ______________ and _____________.
coma
Hypotension
acidosis
_______________ is a special hazard associated with alcohol intoxication and ______________ may occur in children and some adults
Aspiration of vomit
hypoglycaemia
How is alcohol intoxication managed in patients?
Supportively, with particular attention to maintaining a clear airway and measures to reduce the risk of aspiration of gastric contents
Blood glucose is measured and glucose given if indicated
What are the main features of aspirin overdose? (6)
- Hyperventilation
- Tinnitus
- Deafness
- Vasodilation
- Sweating
- Coma (uncommon but indicates very severe poisoning)
Treatment of aspirin overdose must be in hospital, where _____________, ____________, and ____________ can be measured
plasma salicylate
pH
electrolytes
Absorption of aspirin may be ___________ and the plasma-salicylate concentration may continue to rise for several hours, requiring ___________
slow
repeated measurement
Generally, the clinical severity of poisoning is less below a plasma-salicylate concentration of ____________ mg/litre (3.6 mmol/litre), unless there is evidence of metabolic acidosis
500
Activated charcoal can be given within 1 hour of ingesting more than __________ mg/kg of aspirin
125
Fluid losses should be replaced in aspirin overdose and _____________ may be given (ensuring plasma-potassium concentration is within the reference range) to enhance urinary salicylate excretion (optimum urinary pH 7.5–8.5)
intravenous sodium bicarbonate
Plasma-potassium concentration should be corrected before giving sodium bicarbonate as _________________
hypokalaemia may complicate alkalinisation of the urine
______________ concentration should be corrected before giving sodium bicarbonate as hypokalaemia may complicate alkalinisation of the urine
Plasma-potassium
______________ is the treatment of choice for severe salicylate poisoning and should be considered when the plasma-salicylate concentration exceeds 700 mg/litre (5.1 mmol/litre) or in the presence of severe metabolic acidosis
Haemodialysis
Haemodialysis is the treatment of choice for severe salicylate poisoning and should be considered when the plasma-salicylate concentration exceeds __________ mg/litre (5.1 mmol/litre) or in the presence of severe _____________
700
metabolic acidosis
Opioids (narcotic analgesics) cause what symptoms? (3)
- coma
- respiratory depression
- pinpoint pupils
The specific antidote of opioid poisoning, _________________, is indicated if there is coma or bradypnoea
naloxone hydrochloride
The specific antidote of opioid poisoning, naloxone hydrochloride, is indicated if there is ______________ or _______________
coma
bradypnoea
Since naloxone has a shorter ______________ than many opioids, close monitoring and _____________ are necessary according to the respiratory rate and depth of coma
duration of action
repeated injections
Since naloxone has a shorter duration of action than many opioids, close monitoring and repeated injections are necessary according to the _______________ and _______________
respiratory rate
depth of coma
When repeated administration of naloxone is required, it can be given by ________________ and the rate of infusion adjusted according to vital signs
continuous intravenous infusion (instead of IV injection)
When repeated administration of naloxone is required, it can be given by continuous IV infusion and the rate of infusion adjusted according to _______________
vital signs
The effects of some opioids, such as ______________, are only partially reversed by naloxone
buprenorphine
_________________ and _______________ (opioids) have very long durations of action; patients may need to be monitored for long periods following large overdoses
Dextropropoxyphene
methadone
Naloxone reverses the opioid effects of dextropropoxyphene. The long duration of action of dextropropoxyphene calls for _______________ and ______________ may be required
prolonged monitoring
further doses of naloxone
Norpropoxyphene, a metabolite of dextropropoxyphene, also has ______________ effects which may require treatment with sodium bicarbonate or magnesium sulfate, or both. Arrhythmias may occur for up to 12 hours
cardiotoxic
Norpropoxyphene, a metabolite of dextropropoxyphene, also has cardiotoxic effects which may require treatment with ________________ or ______________, or both. Arrhythmias may occur for up to 12 hours
sodium bicarbonate
magnesium sulfate
Norpropoxyphene, a metabolite of dextropropoxyphene, also has cardiotoxic effects which may require treatment with sodium bicarbonate or magnesium sulfate, or both. ______________ may occur for up to ____________
Arrhythmias
12 hours
In all cases of ______________ paracetamol poisoning clinicians are encouraged to contact the National Poisons Information Service for advice on risk assessment and management
intravenous
Toxic doses of paracetamol may cause severe ___________________ and, much less frequently, ___________________
hepatocellular necrosis
renal tubular necrosis
________________ and ______________, the early features of paracetamol poisoning, usually settle within 24 hour
Nausea
vomiting
The recurrence of nausea and vomiting after 2–3 days after paracetamol poisoning, often associated with the onset of right subcostal pain and tenderness, usually indicates development of _______________
hepatic necrosis
Liver damage is maximal ___________ after paracetamol overdose and may lead to liver failure, encephalopathy, coma, and death
3–4 days
Liver damage is maximal 3–4 days after paracetamol overdose and may lead to _______________, _______________, _____________, and _______________
liver failure
encephalopathy
coma
death
To avoid underestimating the potentially toxic paracetamol dose ingested by obese patients who weigh more than __________ kg, use a body-weight of ___________ kg (rather than their actual body-weight) when calculating the total dose of paracetamol ingested (in mg/kg)
110
110
_________________ prevents or reduces the severity of liver damage if given up to, and possibly beyond (in patients at risk of severe liver disease) 24 hours of ingesting paracetamol
Acetylcysteine
Acetylcysteine prevents or reduces the severity of liver damage if given up to, and possibly beyond (in patients at risk of severe liver disease) _______ hours of ingesting paracetamol
24
N-Acetylcysteine is most effective if given within ________ hours of paracetamol ingestion, after which effectiveness declines
8
What is the mode of administration of acetylcysteine?
IV
Very rarely, giving acetylcysteine by mouth [unlicensed] is an alternative if intravenous access is not possible (for further information, see Acetylcysteine—oral doses, available from TOXBASE).
Acute overdose involves ingestion of a potentially toxic dose of paracetamol in ___________ or less.
1 hour
*vs a staggered overdose involves ingestion of a potentially toxic dose of paracetamol over more than 1 hour, with the possible intention of causing self-harm
For adults and children aged 6 years and over, serious toxicity is unlikely to occur from a single ingestion of less than _________ mg/kg of paracetamol taken in less than 1 hour.
75
In which situations should you refer a patient to hospital for medical assessment in the context of acute paracetamol overdose? (4)
- Ingested paracetamol in the context of self-harm
- Are symptomatic (nausea and vomiting)
- Have ingested 75 mg/kg or more in 1 hour or less
- The time of ingestion is uncertain but the dose is 75 mg/kg or more
For children aged under 6 years, serious toxicity is unlikely to occur from a single ingestion of less than _________ mg/kg of paracetamol taken in less than 1 hour.
150
Refer children to hospital for medical assessment in the context of acute paracetamol overdose if … (3)
- They are symptomatic (nausea or vomiting)
- They have ingested 150 mg/kg or more in 1 hour or less
- There is uncertainty about the dose ingested or the circumstances of ingestion
Although the benefit of gastric decontamination is uncertain, charcoal, activated should be considered if the patient presents within ______________ of ingesting paracetamol in excess of 150 mg/kg
1 hour
Patients at risk of liver damage and therefore requiring acetylcysteine, can be identified from a single measurement of the
plasma-paracetamol concentration related to the time from ingestion, provided this time interval is not less than 4 hours; earlier samples cannot be interpreted
A 24 year old female is brought to A&E by her partner following an overdose of 30 tablets of paracetamol 2 hours ago. Should she be admitted? Should she be given activated charcoal? Should her plasma-paracetamol concentration be measured?
Yes; intent for self-harm
No; more than 1 hour has passed since ingestion
Not until 4 hours have passed since the time of ingestion; earlier samples cannot be interpreted
The concentration is plotted on a paracetamol treatment graph, with a reference line (‘treatment line’) joining plots of 100 mg/litre (0.66 mmol/litre) at _____ hours and 3.13 mg/litre (0.02 mmol/litre) at _____ hours
4
24
(The ideal window of treatment with acetylcysteine)
Acetylcysteine treatment should commence in patients patients who satisfy which criteria? (4)
- Plasma paracetamol concentration falls on or above the treatment line
- Who present within 8 hours of ingestion of more than 150 mg/kg of paracetamol if there is going to be a delay of 8 hours or more in obtaining the paracetamol concentration after the overdose
- Who present 8–24 hours after ingestion of an acute overdose of more than 150 mg/kg of paracetamol even if the plasma-paracetamol concentration is not yet available
- Who present more than 24 hours after ingestion of an overdose if they are clearly jaundiced or have hepatic tenderness, their ALT is above the upper limit of normal (patients with chronically elevated ALT should be discussed with the National Poisons Information Service), their INR is greater than 1.3 (in the absence of another cause), or the paracetamol concentration is detectable
Patients should be treated with acetylcysteine if they present within 8 hours of paracetamol overdose (>150 mg/kg) if…
There is going to be a delay of 8 hours or more in obtaining the paracetamol concentration
Patients should be treated with acetylcysteine if they present 8-24 hours of acute paracetamol overdose (>150 mg/kg) if…
If nothing lol
They should be treated. Even if the plasma-paracetamol concentration is not yet available
Patients should be treated with acetylcysteine if they present within >24 hours of paracetamol overdose (>150 mg/kg) if… (4)
- They are clearly jaundiced or have hepatic tenderness
- Their ALT is above the upper limit of normal
- Their INR is greater than 1.3 (in the absence of other causes)
- The paracetamol concentration is detectable
Patients should be treated with acetylcysteine if they present within 8 hours of paracetamol overdose (>150 mg/kg) if they are clearly ___________ or have ___________, their _________ is above the upper limit of normal, their INR is greater than ____________, or the paracetamol concentration is. ____________
jaundiced
hepatic tenderness
ALT
1.3 (in the absence of another cause)
detectable
Consider acetylcysteine treatment in patients who present within 24 hours of an overdose if biochemical tests suggest ____________, even if the plasma paracetamol concentration is below the treatment line on the paracetamol treatment graph
acute liver injury
Where the time of paracetamol ingestion is unknown, patients should be managed as a ________________
staggered overdose
Patients who have ingested more than _________ mg/kg of paracetamol in any 24-hour period are at risk of serious toxicity
150
Toxicity rarely occurs with paracetamol doses between _________ mg/kg in any 24-hour period.
75–150
Doses consistently less than 75 mg/kg in any 24-hour period are very unlikely to be toxic; however risk may be increased if this dose is repeatedly ingested over ______ or more days
2
What is therapeutic excess in the context of paracetamol overdose?
ingestion of a potentially toxic dose of paracetamol with intent to treat pain or fever and without self-harm intent during its clinical use
All patients exposed to a toxic dose of paracetamol in the context of therapeutic excess should be referred to hospital for medical assessment if they meet any of the following criteria … (3)
- Are symptomatic
- Have ingested more than the licensed dose and more than or equal to 75 mg/kg in any 24 hour period OR
- Have ingested more than the licensed dose but LESS than 75 mg/kg/24 hours on each of the preceding 2 or more days
Patients with clinical features of hepatic injury such as _____________ or ______________ should be treated urgently with acetylcysteine
jaundice
hepatic tenderness
- For other patients, management is determined by the maximum dose of paracetamol ingested in any 24-hour period
When there is uncertainty about whether the presentation was due to therapeutic excess, the patient should be managed as a ______________
staggered overdose
A staggered overdose involves ingestion of a potentially toxic dose of paracetamol over more than __________, with the possible intention of causing
1 hour
self-harm
True or False: All patients who have taken a staggered overdose should be referred to hospital for medical assessment
True; furthermore, the MHRA advises that all patients who have ingested a staggered overdose should be treated with acetylcysteine without delay
True or False: All patients who have ingested a staggered overdose of paracetamol should be treated with acetylcysteine without delay
True
Clinically significant hepatotoxicity is unlikely and the patient is not considered to be at risk if… (5)
- There has been at least 4 hours or more since the last paracetamol ingestion AND
- The patient has no symptoms suggesting liver damage
- The paracetamol concentration is less than 10 mg/L
- Their ALT is within the normal range
- And their INR is 1.3 or less
What are the two IV acetylcysteine regimens?
- The standard 21-hour regimen
2. The modified 12-hour regimen (AKA the SNAP regimen), not endorsed by the MHRA
For the standard 21-hour regimen, acetylcysteine is given in a total dose that is divided into _____ consecutive intravenous infusions over a total of 21 hours.
3
How is dosage of acetylcysteine determined?
Based on body weight, varies between 3 doses
(Tables available on BNF)
*should be added to glucose 5% or N/S 0.9% intravenous infusion
First infusion (based on an acetylcysteine dose of approx. ________ mg/kg)—add requisite volume of Acetylcysteine Concentrate for Intravenous Infusion to _______ mL Glucose 5% or sodium chloride 0.9% Intravenous Infusion; infuse over _________
150
200
1 hour
Second infusion (based on an acetylcysteine dose of approx. ________ mg/kg; start immediately after completion of first infusion)—add requisite volume of Acetylcysteine Concentrate for Intravenous Infusion to ________ mL Glucose 5% or sodium chloride 0.9% Intravenous Infusion; infuse over _________
50
500
4 hours
Third infusion (based on an acetylcysteine dose of approx. ______ mg/kg; start immediately after completion of second infusion)—add requisite volume of Acetylcysteine Concentrate for Intravenous Infusion to ______ Glucose 5% or sodium chloride 0.9% Intravenous Infusion; infuse over _______
100
1 litre
16 hours
What are the symptoms of TCA overdose? (11)
- Dry mouth (antimuscarinic effects)
- Coma
- Hypotension
- Hypothermia
- Hyperreflexia
- Extensor plantar responses
- Convulsions
- Respiratory failure
- Cardiac conduction defects, arrhythmias
- Dilated pupils
- Urinary retention
_______________ may complicate severe TCA poisoning
Metabolic acidosis
What symptoms are common during TCA overdose recovery? (3)
- Delirium with confusion
- Agitation
- Visual and auditory hallucinations
Assessment in hospital is strongly advised in case of poisoning by tricyclic and related antidepressants but _______________ can be given before transfer and _______________ are mandatory
symptomatic treatment (eg IV lorazepam)
Supportive measures to ensure a clear airway and adequate ventilation during transfer
_____________ given within 1 hour of TCA overdose reduces absorption
Activated charcoal
Although arrhythmias are worrying, some will respond to _____________
correction of hypoxia and acidosis
In the case of arrhythmias resulting from TCA overdose, ___________ should be avoided. Instead ___________ can arrest arrhythmias and prevent them in those with an extended QRS duration
Anti-arrhythmic drugs
IV infusion of sodium bicarbonate
What drug can be given to patients experiencing delirium as a result of TCA overdose?
Diazepam, PO (large doses may be required)
What are the symptoms of SSRI overdose? (8)
- Nausea and vomiting
- Agitation
- Tremor
- Nystagmus
- Drowsiness
- Sinus tachycardia
- Convulsions
- Serotonin syndrome (rare)
What are the symptoms of serotonin syndrome? (7)
- Marked neuropsychiatric effects
- Neuromuscular hyperactivity
- Autonomic instability
- Hyperthermia
- Rhabdomyolysis
- Renal failure
- Coagulopathies
What is the management of SSRI overdose?
Supportive; activated charcoal IF given within an hour of ingestion and convulsions treated with lorazepam/diazepam/midazolam
Overdosage with quinine, chloroquine, or hydroxychloroquine is extremely hazardous and difficult to treat. Urgent advice from the National Poisons Information Service is essential. Life-threatening features include _______________ (which can have a very rapid onset) and ________________ (which can be intractable)
arrhythmias
convulsions
______________ cause less depression of consciousness and respiration than other sedatives
Phenothiazines
What are the complications of phenothiazine (prochlorperazine and trifluoperazine) poisoning?
- Hypotension
- Hypothermia
- Sinus tachycardia
- Arrhythmias
*dystonic reactions and convulsions may occur at therapeutic doses
In cases of phenothiazines overdose, arrhythmias may respond to _____________ but should not be treated with _____________, which may worsen them
Correction of hypoxia or acidosis
Anti-arrhythmic drugs
Dystonic reactions caused by phenothiazines rapidly respond to injection of ____________ or ______________
Procyclidine
Diazepam
What are the features of poisoning with second generation antipsychotics? (5)
- Drowsiness
- Convulsions
- Extrapyramidal symptoms
- Hypotension
- ECG abnormalities (including QT prolongation)
What ECG abnormality may result from overdose of second-generation antipsychotics?
QT prolongation
What is the management of overdose of second-generation antipsychotics?
Supportive; activated charcoal may be given within 1 hour of ingestion
Benzodiazepines taken alone can cause what symptoms? (6)
- Drowsiness
- Ataxia
- Dysarthria
- Nystagmus
- Respiratory depression
- Coma
Activated charcoal can be given within 1 hour of ingesting a significant quantity of benzodiazepine, provided ________________
the patient is awake and the airway is protected
Benzodiazepines ________________ of other central nervous system depressants taken concomitantly
potentiate the effects
Flumazenil should be avoided in which scenarios? (2)
- Mixed overdoses (ie those involving TCAs)
2. Benzodiazepine-dependent patients (may precipitate withdrawal)
In patients experiencing symptoms of benzodiazepine overdose, _______________ may prevent the need for ventilation, particularly in patients with severe respiratory disorders
Flumazenil
Flumazenil should be used on expert advice only and not as a _______________ in patients with a reduced level of consciousness.
diagnostic test
What are the symptoms of beta-blocker overdose? (7)
- Bradycardia (most common)
- Hypotension
- Syncope
- Conduction abnormalities
- HF
- QT prolongation (sotalol)
- QRS prolongation (propranolol)
The effects of overdosage can vary from one beta-blocker to another; propranolol overdosage in particular may cause _____________ and ______________
coma
convulsions
(As well as QRS prolongation)
Which beta-blocker in overdose is associated with QT prolongation and associated arrhythmias?
Sotalol
All patients who have been exposed to beta-blockers as a result of ___________ should be referred for assessment
self-harm
For patients presenting with beta-blocker overdose, _______________. Although the benefit of gastric decontamination is uncertain, charcoal, activated can be considered if the patient presents within 1 hour of ingestion of more than a potentially toxic dose
maintain a clear airway and adequate ventilation
For the management of hypotension associated with beta-blocker overdose, ensure adequate fluid resuscitation; in an emergency, _____________ and ______________ can be initiated under the advice of an experienced physician
vasopressors
inotropes
- Intravenous glucagon [unlicensed] is a treatment option for severe hypotension, heart failure, or cardiogenic shock
In severe cases of beta-blocker toxicity, an ____________ and ____________ infusion can improve myocardial contractility and systemic perfusion, especially in the presence of acidosis
insulin
glucose
- Intravenous glucagon [unlicensed] is also a treatment option for severe hypotension, heart failure, or cardiogenic shock
In cases of beta-blocker overdose, consider intravenous _________________ for correction of metabolic acidosis that persists despite correction of hypoxia and adequate fluid resuscitation—rapid correction is particularly important if __________________
sodium bicarbonate
QRS duration is prolonged
In cases of beta-blocker toxicity, give intravenous _________________ for symptomatic bradycardia; a temporary cardiac pacemaker can be used to increase the heart rate
atropine sulfate
*dobutamine [unlicensed] or isoprenaline [unlicensed] (available from ‘special-order’ manufacturers or specialist importing companies) may be considered if bradycardia is associated with hypotension.
Treat beta-blocker associated bronchospasm with ______________ and _______________
nebulised bronchodilators
corticosteroids
What is the management of convulsions associated with beta-blocker overdose? (3)
Give oxygen
Correct acid-base and metabolic disturbances as required
Prolonged and frequent convulsions should be controlled with IV diazepam, lorazepam, or midazolam
What are the features of CCB (dihydropyridines) poisoning? (8)
- Nausea and vomiting
- Dizziness
- Agitation
- Confusion
- Coma
- Metabolic acidosis
- Hyperglycemia
- Hypotension (profound peripheral vasodilation)
What are the symptoms of verapamil and diltiazem in overdose (non-dihydropyridine CCBs)? (2)
- Hypotension (negative inotropic effects)
2. Arrhythmias including complete heart block and asystole
_____________ should be considered if the patient presents within 1 hour of overdosage with a calcium-channel blocker
Activated charcoal; repeated doses of activated charcoal are considered if a modified-release preparation is involved
In patients with significant features of CCB poisoning, ______________ or ____________ is given by injection; atropine sulfate is given to correct symptomatic bradycardia
calcium chloride
calcium gluconate
In patients with significant features of CCB poisoning, calcium chloride or calcium gluconate is given by injection; ______________ is given to correct symptomatic bradycardia
atropine sulfate
In severe cases of CCB poisoning, an ______________ and _______________ infusion may be required in the management of hypotension and myocardial failure
insulin
glucose
Iron poisoning in childhood is usually ________________
Accidental
What are the symptoms of iron poisoning? (10)
- Nausea and vomiting
- Abdominal pain
- Diarrhea
- Hematemesis
- Rectal bleeding
- Hypotension (later)
- Hepatocellular necrosis (later)
- Coma
- Shock
- Metabolic acidosis
Mortality from iron poisoning is reduced by intensive and specific therapy with ______________
desferrioxamine mesilate (chelates iron)
*The serum-iron concentration is measured as an emergency and intravenous desferrioxamine mesilate given to chelate absorbed iron in excess of the expected iron binding capacity. In severe toxicity intravenous desferrioxamine mesilate should be given immediately without waiting for the result of the serum-iron measurement.
