Cardiovascular Critical Care II
Neurologic
Circulation 2008;118:2452-83;
Ther Hypothermia Temp Manag
2016;6:189-93)
Sedation and Analgesia:
Adequate pain control and sedation must be used
Target Richmond Agitation and Sedation Scale score of -3 to -5 (see chapter
on sedation for agent selection and dosing) during hypothermia
Accumulation of parent and active metabolites can be expected for each
analgesic and sedative, which leads to prolonged sedation and poten-
tially untoward adverse effects (see Table 5 for examples)
Seizures:
Possible complication of cardiac arrest and therapeutic hypothermia
Consider benzodiazepines as first line to abort seizure
Phenytoin, barbiturates, valproic acid, and propofol can all be used, with
vigilant monitoring of adverse effects because of decreased clearance
(see Table 5 for examples; for dosing and monitoring values, see the
Status Epilepticus section in the Neurocritical Care chapter)
Intracranial Pressure:
Increases post-cardiac arrest likely because of ischemic injury and
cytotoxic edema and is partially attenuated by temperature control
Major increase appears to occur during rewarming phase of temperature
control
Uncertain if targeted reduction therapy would impact outcomes
Cardiac
Anesthesiol Clin 1964;2:803-27)
Arrhythmias:
Include VT, VF, and atrial fibrillation
If life threatening, should consider discontinuing therapeutic hypothermia
and active rewarming
Sinus bradycardia is common during cooling and, in isolation, should not be
treated unless it leads to hemodynamic instability (e.g., hypotension or
organ dysfunction)
ECG observations:
Prolonged PR, QRS, and QT intervals
Caution should be exercised when using medications that prolong the QT
interval
Hemodynamics:
Decreased cardiac output
Fluid shifts away from central compartment
Vasoconstriction during cooling, which may lead to increased blood
pressure
Vasodilation during rewarming, which may lead to decreased blood
pressure
Hepatobiliary
Ther Drug Monit 2001;23:192-7;
Anesthesiology 2000;92:84-93;
Clin Pharmacol Ther 1979;25:1-7)
Elevated transaminases
Reduced activity of non-cytochrome and cytochrome P450–mediated
metabolism
See Table 5 for examples of metabolic changes in selected medications
during hypothermia