Mild/moderate hypothermia

MODULATION OF ISCHEMIC INJURY BY MILD TO MODERATE HYPOTHERMIA... 

The extent to which the BBB is influenced by ischemia is highly temperature dependent. Early BBB breakdown to protein tracers is demonstrable after normothermic global ischemia but is suppressed by mild to moderate hypothermia and is greatly accentuated by intraischemic hyperthermia (71,112). Similarly, postischemic edema following global ischemia is reduced by moderate hypothermia (113). 

During the last 10 yr the results of five trials of therapeutic mild to moderate hypothermia for the treatment of severe TBI have been published (Table 1) (17,20-23). Although there were slight differences in the duration of cooling (1 vs 2 d) and time to initiation of cooling (within... 

A profound or moderate hypothermia below 20°C or 30°C in body temperature has been known to protect the brain from ischemic insults for many years. Profound or moderate hypothermia is, however, almost exclusively accompanied by serious cardiac suppression or other adverse effects, and hence regarded as inappropriate as a therapeutic tool except for the purpose of cerebral protection during open-heart surgery. In 1989, Busto et al. (19) reported that mild hypothermia in the range of 30-33°C exerted potentially protective effects on neuronal... 

Resurgence of Hypothermia as a Treatment for Brain Injury. The Effects of Hypothermia and Hyperthermia in Global Cerebral Ischemia. Mild Hypothermia in Experimental Focal Cerebral Ischemia. Hypothermic Protection in Traumatic Brain Injury. Postischemic Hypothermia Provides Long-Term Neuroprotection in Rodents. Combination Therapy With Hypothermia and Pharmaceuticals for the T reatment of Acute Cerebral Ischemia. Intraoperative and Intensive Care Management of the Patient Undergoing Mild Hypothermia. Management of Traumatic Brain Injury With Moderate Hypothermia. Hypothermia Clinical Experience in Stroke Patients. Hypothermia Therapy Future Directions in Research and Clinical Practice. Index. 

Cold weather decreases the total number of injuries, but it does produce a variety of injuries and illnesses that are unique to colder temperatures. Cold injuries can be divided into local cold injuries and the systemic state of hypothermia. Hypothermia is further classified as mild, moderate, and severe. Local cold injuries include frostbite, frostnip, and chilblains. Barnes (2002) describes the spectrum of cold injuries ... 

Hypothermia extends the survival time and prevents the development of brain edema in rats with ALE, caused by hepatic devascularization and mild hypothermia (33—35°C), reduces ammonia-induced brain swelling and increased intracranial pressure in portacaval-shunted rats administered ammonium salts. These findings have led to the successful use of mild hypothennia for the treatment of uncontrolled intracranial hypertension in patients with ALF (Jalan et al., 1999). Mechanisms so far identified that underhe the beneficial effect of hypothermia in ALF include reduced blood-brain transfer of ammonia, improved cerebrovascular hemodynamics and normafization of extracellular brain amino acid patterns (for review of these mechanisms, see Vaquero et al., 2005). Mild hypothermia also improves hepatic function in experimental toxic fiver injury (Vaquero et al., 2(X)7) Mild-to-moderate hypothermia has the potential to serve as an important strategy in the management of patients with ALF awaiting liver transplantation. 

Hypothermia in the trauma patient is multifactorial, resulting from exposure to cold environment, bleeding, and infusion of cold fluids. Mild to moderate hypothermia (34°C to 30 C) can be associated with coagulopathy that can impair the patient s response to ongoing resuscitation and at times be refractory to treatment [32]. During massive resuscitation, hypothermia can be avoided by administration of warmed fluids, either by means of an in-line warmer, or rapid infuser. The ambient room temperature should be maintained at 2rC. Additionally, patients can also be actively warmed by one of the commercially available convective blankets. 

Rabbits exposed 6 hours/day to 2 72 ppm over a 10-week period showed slight eye irritation at 997 ppm additional effects were salivation, lethargy, narcosis, mild convulsive movements, and some deaths. Lethal doses of cyclohexanol produced slight necrosis of the myocardium and damage to the lungs, liver, and kidneys. The application of 10 ml of cyclohexanol to the skin of a rabbit for 1 hour/day for 10 days induced narcosis, hypothermia, tremors, and athetoid movements necrosis, exudative ulceration, and thickening of the skin occurred in the area of contact. Ten microliters applied directly to the cornea of rabbits caused moderate to severe irritation. ... 

The salutary influence of mild to moderate degrees of intraischemic hypothermia in models of global ischemia raised the clinically relevant issue of whether postischemic cooling to the same degree would also... 

Toxicity weakness, drowsiness, confusion, agitation, delirium, hallucinations, nausea and vomiting are common in mild to moderate toxicity. Respiratory depression, hypotension, bradycardia, hypotonia, hypothermia, seizures, and coma may occur in severe toxicity. Rare events include status epilepticus, rhabdomyolysis, and first-degree AV block. Oral doses of200 mg or more and intrathecal doses of 1.5 mg or more often produce significant toxicity. 

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