Current Clinical Strategies, Critical Care and Cardiac Medicine (2005); BM OCR 7.0 2.5

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infusion should be initiated.
D.Glucose, 50 mL of 50 percent, should be given
immediately if hypoglycemia is suspected because
hypoglycemia may precipitate status epilepticus and
is quickly reversible. If the physician cannot check for
hypoglycemia or there is any doubt, glucose should be
administered empirically. Thiamine (100 mg) should
be given along with the glucose, because glucose
infusion increases the risk of Wernicke's enceph�
alopathy in susceptible patients.
E.Blood gas levels should be determined to ensure
adequate oxygenation. Initially, acidosis, hyperpyrexia,
and hypertension need not be treated, because these
are common findings in early status epilepticus and
should resolve on their own with general treatment. If
seizures persist after initial measures, medication
should be administered. Imaging with computed
tomography is recommended after stabilization of the
airway and circulation. If imaging is negative, lumbar
puncture is required to rule out infectious etiologies.
III.Electroencephalography
A.Electroencephalography (EEG) is extremely useful
in the diagnosis and management of status
epilepticus. EEG can establish the diagnosis in less
obvious circumstances.
B.EEG also can help to confirm that an episode of
status epilepticus has ended. Patients with status
epilepticus who fail to recover rapidly and completely
should be monitored with EEG for at least 24 hours
after an episode.
IV.Pharmacologic management
A.Benzodiazepines
1.The benzodiazepines are some of the most
effective drugs in the treatment of acute seizures
and status epilepticus. The benzodiazepines most
commonly used to treat status epilepticus are diaz�
epam (Valium), lorazepam (Ativan), and
midazolam (Versed).
2.Lorazepam (Ativan)
a.Lorazepam has emerged as the preferred
benzodiazepine for acute management of
status epilepticus. Lorazepam is less lipid�
soluble than diazepam, with a distribution half�
life of two to three hours versus 15 minutes for
diazepam. Therefore, it has a longer duration of
clinical effect. Lorazepam also binds the
GABAergic receptor more tightly than diaze�
pam, resulting in a longer duration of action.
b.Anticonvulsant effects of lorazepam last six to
12 hours, and the typical dose ranges from 4 to
8 mg (0.1 mg/kg). Lorazepam has a broad
spectrum of efficacy, terminating seizures in 75
to 80 percent of cases. Adverse effects include
respiratory suppression, hypotension, sedation,
and local tissue irritation.
3.Phenytoin
a.Phenytoin (Dilantin) is one of the most effec�
tive drugs for treating acute seizures and status
epilepticus. In addition, it is effective in the
management of chronic epilepsy.
b.The main advantage of phenytoin is the lack
of a significant sedating effect. Arrhythmias and
hypotension have been reported with the IV
formulation. These effects are associated with
a more rapid rate of administration and the
propylene glycol vehicle used as its diluent. In
addition, local irritation, phlebitis, and dizziness
may accompany intravenous administration.
Antiepileptic Drugs Used in Status Epilepticus
Drug Loading Mainte- Adverse
dose nance effects
dosage
Respiratory
Lorazepam depression,
4-8 mg None
(Ativan) hypotension,
sialorrhea
15 to 18 mg
Cardiac de�
Phenytoin per kg at 50 5 mg per kg
pression,
(Dilantin) mg per min� per day
hypotension
ute
18 to 20 mg
4-6 mg
per kg Cardiac de-
PE/kg/day
Fosphenytoi phenytoin pression,
n (Cerebyx) equivalents hypotension,
at 150 mg paresthesias
per minute
2 mg per
Phenobarbi- 20 mg per Respiratory
kg/kg IV
tal kg suppression
q12h
Hypotension
Pentobarbita 10 mg per 1-1.5 mg per
, respiratory
l kg kg per hour
suppression
0.05 to 0.6 Hypotension
Midazolam 0.2 mg per
mg per kg , respiratory
(Versed) kg
per hour suppression
5 to 10 mg Respiratory
per kg per depression,
Propofol
2 mg per kg hour initially, hypotension,
(Diprivan)
then 2-10 lipemia, aci�
mg/kg/hr dosis
4.Fosphenytoin
a.Fosphenytoin (Cerebyx) is a water-soluble pro�
drug of phenytoin that completely converts to
phenytoin. Thus, the adverse events that are
related to propylene glycol are avoided. Like
phenytoin, fosphenytoin is useful in treating acute
partial and generalized tonic-clonic seizures.
Fosphenytoin is converted to phenytoin within eight
to 15 minutes. Because 1.5 mg of fosphenytoin is
equivalent to 1 mg of phenytoin, the dosage,
concentration, and infusion rate of intravenous fos�
phenytoin are expressed as phenytoin equivalents
(PE).
Protocol for Management of Status Epilepticus
At: zero minutes
Initiate general systemic support of the airway (in�
sert nasal airway or intubate if needed)
I. Check blood pressure.
II. Begin nasal oxygen.
III. Monitor ECG and respiration.
IV. Check temperature frequently.
V. Obtain history.
VI. Perform neurologic examination.
Send sample serum for evaluation of electrolytes,
blood urea nitrogen, glucose level, complete blood
cell count, toxic drug screen, and anticonvulsant
levels; check arterial blood gas values.
Start IV line containing isotonic saline at a low infu�
sion rate.
Inject 50 mL of 50 percent glucose IV and 100 mg of
thiamine IV.
Call EEG laboratory to start recording as soon as
feasible.
Administer lorazepam (Ativan) at 0.1 to 0.15 mg per
kg IV (2 mg per minute); if seizures persist, adminis�
ter fosphenytoin (Cerebyx) at 18 mg per kg IV (150
mg per minute, with an additional 7 mg per kg if
seizures continue).
At: 20 to 30 minutes, if seizures persist
Intubate, insert bladder catheter, start EEG record�
ing, check temperature.
Administer phenobarbital in a loading dose of 20 mg
per kg IV (100 mg per minute).
At: 40 to 60 minutes, if seizures persist
Begin pentobarbital infusion at 5 mg per kg IV initial
dose, then IV push until seizures have stopped,
using EEG monitoring; continue pentobarbital infu�
sion at 1 mg per kg per hour; slow infusion rate
every four to six hours to determine if seizures have
stopped, with EEG guidance; monitor blood pres�
sure and respiration carefully. Support blood pres�
sure with pressors if needed.
or
Begin midazolam (Versed) at 0.2 mg per kg, then at
a dosage of 0.05-0.6 mg/kg/min, titrated to EEG
monitoring.
or
Begin propofol (Diprivan) at 1 to 2 mg per kg loading
dose, followed by 2 to 10 mg per kg per hour. Adjust
maintenance dosage on the basis of EEG monitor�
ing.
b.The initial dose of fosphenytoin is 15 to 20 mg
PE per kg, given at 150 mg PE per minute.
Fosphenytoin may be administered IV or IM,
although IM administration has a 3-hour delayed
peak effect.
c.Adverse effects that are unique to fosphenytoin
include perineal paresthesias and pruritus. Unlike
phenytoin, fosphenytoin does not cause local
irritation. Intravenous therapy has been associ-
ated with hypotension, so continuous cardiac and
blood pressure monitoring are recommended.
5.Phenobarbital
a.Phenobarbital is used after lorazepam or
phenytoin has failed to control status epilepticus.
The normal loading dose is 15 to 20 mg per kg.
Because high-dose phenobarbital is sedating,
airway protection is important, and aspiration is a
major concern. Intravenous phenobarbital also is
associated with hypotension. It is diluted in 60 to
80 percent propylene glycol, which is associated
with renal failure, myocardial depression, and
seizures.
Endocrinologic and
Nephrologic Disorders
Diabetic Ketoacidosis
Diabetic ketoacidosis is defined by hyperglycemia,
metabolic acidosis, and
ketosis.
I.Clinical presentation
A.Diabetes is newly diagnosed in 20% of cases of
diabetic ketoacidosis. In patients with known diabetes,
precipitating factors include infection, noncompliance
with insulin, myocardial infarction, and gastrointestinal
bleeding.
B.Symptoms of DKA include polyuria, polydipsia,
fatigue, nausea, and vomiting, developing over 1 to 2
days. Abdominal pain is prominent in 25%.
C.Physical examination
1.Patients are typically flushed, tachycardic,
tachypneic, and volume depleted with dry mucous
membranes. Kussmaul's respiration (rapid, deep
breathing and air hunger) occurs when the serum pH
is between 7.0 and 7.24.
2.A fruity odor on the breath indicates the presence
of acetone, a byproduct of diabetic ketoacidosis. [ Pobierz całość w formacie PDF ]

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