Resuscitation in Toxicology
Supportive care
Initial resuscitation should be
based on the assessment of the patient and not the particular toxin involved
and standard advanced life support (ALS) guidelines should be followed.Specific instances where
treatment may differ are indicated below.
The majority of
patients taking overdoses or with drug toxicity are young and healthy, so
cardiac and respiratory support should be continued for much longer periods of
time in patients with a toxicity-related cardiorespiratory arrest.
If there is any doubt, cardiac
compression and ventilatory support should be continued until the situation has
been discussed with a clinical toxicologist. There has been survival with
normal neurological function in patients receiving cardiopulmonary
resuscitation (CPR) for hours.
There are no specific differences
from Resuscitation except for caustic and corrosive ingestions . CNS depression
is a common effect of drugs, so regular and careful assessment of airway
protection and patency is important.
Toxicology patients rarely have
hypoxia unless they develop aspiration pneumonitis. The commonest problem is
hypoventilation secondary to respiratory depression.
The use of intravenous fluid therapy
and inotropic support should be based on patient haemodynamics and the specific
toxins ingested.
Although specific inotropes or or
other drugs are suggested in toxicology patients, the initial management of
cardiogenic shock should be the same as for any other cause unless there
are specific contraindications to particular inotropes. The initial inotrope of
choice is adrenaline unless its vasopressor actions are contraindicated, such
as in beta blocker overdose. Administration of an inotrope should only be
undertaken in consultation with a toxicologist or cardiologist.
Other inotropes are used in
toxicology, but should usually be used in consultation with a clinical
toxicologist. Usual doses of these are given in Box below
Prolonged cardiopulmonary
resuscitation is essential because unlike in arrests due to cardiovascular
disease, the majority of patients are healthy prior to the overdose, and
survival with normal neurological function after long periods (hours) of
cardiopulmonary resuscitation is well documented.
Milrinone (phosphodiesterase
inhibitor)
Insulin euglycaemia
Dobutamine
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Drug-induced arrhythmias
QT prolongation and torsades de
pointes: QT prolongation should be monitored and any other precipitating
factors should be determined and treated if possible. Electrolytes, including
magnesium and calcium, should be checked and deficiencies corrected.
Patients with hypomagnesaemia should
have magnesium replacement. [Note 1]
In adults, use:
magnesium sulfate 50% 5 to 10 mL (= 2.5 to 5 g or 10 to 20 mmol) IV over 30
to 60 minutes.
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In children, use:
magnesium sulfate 50% 0.1 mL/kg (= 50 mg/kg or 0.2 mmol/kg) IV over 20
minutes [Note 2], followed by 0.06 mL/kg/hour (= 30 mg/kg/hour or 0.12
mmol/kg/hour) IV infusion.
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Patients with hypocalcaemia should
have calcium replaced. Use:
In adults, use:
calcium gluconate 10% 10 to 20 mL (= 1 to 2 g or 2.2 to 4.4 mmol) IV, over
10 to 30 minutes.
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In children, use:
calcium gluconate 10% 2 to 5 mL/kg/day (= 200 to 500 mg/kg/day) IV
infusion.
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Patients with hypokalaemia should
have potassium replaced. If the patient is able to take and absorb oral
potassium, use:
potassium chloride 14 to 16 mmol
orally, 3 times daily (child: 1 mmol/kg/day in 2 to 4 doses) [Note 3].
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If the serum potassium is less than
3 mmol/L or the patient is unable to take or absorb oral potassium, use:
potassium chloride 10 to 20 mmol
(= 0.75 to 1.5 g) IV, over 1 to 2 hours (child: 0.6 mmol/kg IV over 3 hours)
preferably as a pre-mixed solution of the appropriate intravenous fluid.
[Note 4].
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Isoprenaline or transvenous pacing
should be considered in patients with a prolonged QT interval and bradycardia.
In adults, use:
isoprenaline 20 micrograms IV,
repeat according to clinical response, and commence an infusion at 1 to 4
micrograms/minute, but the rate may need to be rapidly increased to give
double, quadruple or higher doses as required to overcome the beta blockade.
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Torsades de pointes may resolve
spontaneously within a minute but if not, first-line treatment is a 200 J DC
shock or equivalent. If there is no response to an initial DC shock this can be
repeated with increasing voltage shocks. Magnesium should also be given (except
in torsades de pointes resulting from beta blocker overdose, see Toxicology:
beta blockers).
In adults, use:
magnesium sulfate 50% 2 to 4 mL (= 1 to 2 g or 4 to 8 mmol) IV as a slow
injection over 2 to 5 minutes.
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In children, use:
magnesium sulfate 50% 0.05 to 0.1 mL/kg to a maximum of 4 mL (= 0.025 to
0.05 g/kg or 0.1 to 0.2 mmol/kg to a maximum of 8 mmol/dose) IV as a slow
injection over 10 to 15 minutes.
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If there is deterioration to
ventricular fibrillation or asystole, standard advanced life support protocols
should be followed, see Figure 14.4 and Figure 14.5.
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