Page 1171 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

810 PART 6: Neurologic Disorders

TABLE 86-13 Hyperosmolar and Hypertonic Treatment Modalities
Mannitol 2% NaCl 3% NaCl 23.4% NaCl Hypertonic Sodium lactate
Dose recommenda- 0.25-1 g/kg/dose IV bolus Initial infusion at 1-2 ml/kg/hr; Initial infusion at 1-2 ml/kg/hr; Refractory elevated ICP: IV Loading dose:
tions over 1-30 minutes and may 250 ml bolus over 30 mins may 250 ml bolus over 30 mins may (30-60 ml) given over 2-20 minutes; 3-5 ml/kg over 15-30 minutes
be given repeatedly every be administered; can be given be administered; can be given can be given repeatedly over Continuous infusion:
4-8 hours repeatedly over 30 minutes repeatedly over 30 minutes 15 minutes 0.5-1 ml/kg/hr
Recommended 2 g/kg/dose 1 mEq/kg/hr = 2.9 mL/kg/hr 1 mEq/kg/hr = 1.9 mL/kg/hr May repeat in 6 hours, if target 10 mL/kg in 12 hours intravenously
maximum dose Na not met = 0.83 mL/kg/hr
Route PIV or CIV PIV or CIV CIV CIV PIV or CIV
PIV: Peripheral IV
CIV: Central IV
Osmolarity 1098 mOsm/L 684 mOsm/L 1027 mOsm/L 8008 mOsm/L 1020 mOsm/L
Onset and duration of Onset
action Diuretic effect: 1-3 hours Onset: rapid
Reduction of ICP: 15 minutes Peak: rapid
Duration Mean duration: 4 hours and 17 minutes
Diuretic effect: 4-6 hours
Reduction of ICP: 3-8 hours
Maximum serum 320 mOsm/L 360 mOsm/L
osmolality
Effectiveness May exhibit tolerance with Effective after repeated administration and when tolerance Beneficial as a rescue therapy to Effective after repeated admin-
repeated administration to mannitol has occurred rapidly induce hyperosmolality istration and when tolerance to
mannitol has occurred
Change in mean Moderate increase, initially Greater, more prolonged
arterial pressure
Diuretic effect Osmotic diuretic, may necessitate Diuresis through the stimulation of ANP release
volume replacement to avoid
hypovolemia and hypotension
Other suggested Antioxidant effects Restoration of resting membrane potential and cell volume, inhibition of inflammation
interactions
Cautions Transient volume overload, Hypotension (infusion Thrombophlebitis tissue Transient hypotension, Metabolic alkalosis, electrolyte
pulmonary edema, osmotic related) phlebitis (less necrosis if excavated, thrombophlebitis, tissue imbalance, panic attack
diuresis, pulmonary edema, than with higher sodium hypotension (infusion necrosis if extravasated
CHF, hypertension, sodium concentration) related)
depletion, electrolyte abnor- Rebound ICP elevation; central pontine myelinolysis, coagulopathy (bleeding), electrolyte
malities, acidosis, increase abnormalities (hypo K , Hyper Cl and Na ), metabolic acidosis, CHF, pulmonary edema
-
+
+
cerebral blood flow and risk of
post-operative bleeding
Additional comments One preparation; most reason- Other preparations available: One preparation
able price requires in-line filter 5% saline (mOsm/kg = 1710)
for administration 7.5% saline (mOsm/kg = 2566)
14.6% saline(mOsm/kg = 5370)

36°C. Since shivering can increase ICP and metabolic demand, it should Some of its ICP-lowering benefit may be from depression of cerebral
be anticipated, and sedatives, opiates, and neuromuscular blocking metabolism, reduction of CBF to normal brain tissue, and shunting of
agents given to limit shivering. Rebound intracranial hypertension is an blood to ischemic areas. In addition, barbiturates may limit oxidative
important concern during the rewarming process, so patients should damage to lipid membranes and may scavenge free radicals, reduce
109
be allowed to rewarm slowly (eg, 1°C every 24 hours) with close atten- vasogenic edema, attenuate fatty acid release, reduce intracellular
tion to ICP. Common complications of induced hypothermia include calcium, and limit arousal to external stimuli.
bradycardia at lower core temperatures, electrolyte imbalance such as The correct induction of barbiturate coma is complex and demands
hypokalemia (cooling) and hyperkalemia (rewarming), coagulopathy, experience to ensure its safe and proper use. The agents most com-
and infections. 131-134 monly used are thiopental and pentobarbital. Pentobarbital is commonly
preferred because of its greater water solubility and more predictable
Pharmacologic Suppression: Barbiturate coma is a part of the advanced pharmacokinetics. A fall in CPP from hypotension, complications of
treatment armamentarium to decrease the potential for brain injury prolonged immobility and mechanical ventilation, and immune suppres-
from uncontrolled ICP by reducing metabolic brain activity. While sion are the most common deleterious effects of barbiturate therapy.
barbiturates have been used with variable success for the treatment of Pentobarbital coma requires a loading dose of 10 to 30 mg/kg. In our
elevated ICP, there is little evidence that they improve outcome. 135-139 experience, it is best to administer pentobarbital in small boluses of 100
Barbiturate-induced coma is associated with significant morbidity to 200 mg every 10 to 20 minutes as tolerated from a blood pressure
and hence, it should be reserved for cases of refractory ICP elevation. standpoint. This should be done under electroencephalographic (EEG)

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