Pediatric emergency medicine trisk 2615 2615
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (45.97 KB, 1 trang )
mental status. Another dose may be repeated after 5 minutes. An alternative is
diazepam (Valium), 0.15 to 0.2 mg/kg IV (usual maximum 10 mg/dose), which
has a similarly rapid onset of action. If IV or intraosseous access cannot be
established, diazepam may be administered rectally in a dose of 0.5 mg/kg
(maximum 20 mg/dose), instilling the IV formulation with a slip-tip syringe
(remove needle) or by using a specific rectal gel preparation.
All the benzodiazepines can cause sedation and respiratory depression, which
may persist for hours. Equipment for establishing an airway and supporting
respiration must be available, especially if repeated doses are used. Ideally,
noninvasive ETCO2 monitoring will be used to help assess ventilation in addition
to auscultation and pulse oximetry. Hypotension is uncommon but may be a
problem with multiple doses or when barbiturates are administered
concomitantly.
If the seizures have not been controlled within 10 minutes with
benzodiazepines, a second-line agent should be administered. Current evidence
does not strongly support a preferred second-line agent. Appropriate options to
consider include fosphenytoin, valproic acid (VPA), and levetiracetam.
Consideration should be given to current AED therapy when making a choice.
Fosphenytoin is a prodrug of phenytoin, which is rapidly metabolized to the
active form. It offers several advantages over phenytoin, including more rapid
administration and fewer local and systemic side effects. Fosphenytoin may also
be given IM, unlike phenytoin. The dose of the two drugs is identical;
fosphenytoin doses are expressed as phenytoin equivalents (PE). The loading
dose of fosphenytoin is 20 mg PE/kg IV, maximum single dose of 1,500 mg
PE/dose, at a rate of 3 mg PE/kg/min to a maximum of 150 mg/min. In the
absence of any clinical effect, an additional 10 mg/kg IV may be administered.
Cardiac monitoring is required because rapid IV infusion may lead to
hypotension, QT prolongation, and cardiac dysrhythmias. If phenytoin is used
instead, the maximum rate of administration is 2 mg/kg/min in children and 50
mg/min in an adult. In patients known to be taking phenytoin chronically, a
smaller dose of 5 to 10 mg/kg should be used initially unless the serum level is
known to be very low. Each 1 mg/kg of phenytoin administered raises the serum
level by approximately 1 μg/mL, although phenytoin kinetics are unpredictable.
Phenytoin is highly lipid soluble and reaches therapeutic levels in the brain within
10 to 20 minutes, with duration of action of 12 to 24 hours. Unlike other
anticonvulsant medications, phenytoin does not cause sedation or respiratory
depression.
