Microcirculation During Hypothermia

Bond, Ted P.

doi:10.1001/archsurg.1964.01320050133012

Cited by 16 publications

(4 citation statements)

References 2 publications

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“…Inhomogeneity of flow during hypothermia has been found in other vascular beds such as the mesentery of rats 32 and dogs. 33 The brain metabolites prior to re-warming were consistent with a marginally abnormal cerebral status. Following rewarming, these abnormalities were clearly magnified presumably as a reflection of an inadequate CBF, both regionally and globally.…”

mentioning

confidence: 81%

Deterimental effect of prolonged hypothermia in cats and monkeys with and without regional cerebral ischemia.

Steen¹,

Soule²,

Michenfelder³

1979

Stroke

123

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In a previous study occlusion of a middle cerebral artery (MCA) followed by 48 h of hypothermia (29 degrees) was lethal in 5 of 5 monkeys as compared to only 3 of 9 normothermic animals. The present study extended these observations in monkeys and cats with or without MCA occlusion. In monkeys MCA occlusion plus 48 h of hypothermia was consistently lethal. Without MCA occlusion of 2 of 3 monkeys survived, but were comatose the first 12 h post-hypothermia. In normothermic cats, MCA occlusion was lethal in only one of 5 animals whereas hypothermia was lethal in 20 of 21 cats with or without MCA occlusion. The detrimental effects of hypothermia were not favorably influenced either by hemodilution or by deliberate alterations in PaCO2. The effect of 48 h of hypothermia and rewarming on cerebral blood flow (CBF) and cerebral metabolites was evaluated in 6 normal monkeys. CBF was reduced 60 to 70 percent at 29 degrees C and returned to only a maximum of 50 percent of control with re-warming. Prior to re-warming distribution of CBF was inhomogeneous. Cerebral metabolites were borderline normal prior to re-warming but energy stores decreased while lactate increased with re-warming.

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mentioning

confidence: 81%

Deterimental effect of prolonged hypothermia in cats and monkeys with and without regional cerebral ischemia.

Steen¹,

Soule²,

Michenfelder³

1979

Stroke

123

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“…It was presumed that low-temperature viscosity may have caused the deficiencies in the brain microcirculation. Other studies have suggested that red cell aggregates may partially obstruct the capillary beds,leading to poor tissue perfusion ( 11,12). Initially, the use of stored blood as the priming fluid had many shortcomings ranging from blood pool syndrome to disease transmission.…”

Section: Discussionmentioning

confidence: 99%

Blood Substitution: An Experimental Study

Elrifai,

Bailes,

Leavitt

et al. 1992

J Extra Corpor Technol

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Priming fluids for cardiopulmonary bypass have been extremely varied, with resultant hemodilution. Furthermore, major surgeries utilizing cardiopulmonary bypass require multiple postoperative transfusions of blood and blood products. The appeal of having a readily available blood substitute for major cardiovascular and neurosurgical operations could prove to be a life saver, while also eliminating the risk of diseases transmitted by transfusion. Blood substitutes could also lessen the reported complications resulting from blood damage due to prolonged circulation of the blood by the extracorporeal pump. A technique was examined in 15 dogs using hypothermia for maximum metabolic suppression, incorporating an aqueous blood substitute (Cryomedical Sciences, Inc., Rockville, MD). The anesthetized animals were cannulated for extracorporeal pump oxygenation. As temperature was lowered the dogs were exsanguinated and volume replaced with blood substitute to lower the hematocrit to <1 %. After 3 hours of cardiac arrest and continuous perfusion at a core temperature < 10°C, rewarming began. When temperature reached ≥ 10°C, the blood substitute was drained and the animals were autotransfused. The heart was started at l5°C and spontaneous respiration resumed at 29°C. Using the first generation blood substitute the survival rate was maximal (100%) at 2.5 hrs under 10°C and 3 hours of cardiac arrest. Research is underway on a new blood substitute, which is to serve as a universal hypothermic preservation solution (in situ organ preservation). When perfected, combining total blood substitution and cooling to ultraprofound (< 10°C) levels may prove beneficial in sustaining cerebral ischemia for prolonged time periods, without incurring major metabolic debt. This may provide significant benefits for neurovascular surgery by prolonging the safe limits of cardiac arrest for several hours, rendering currently inoperable tumors and aneurysms more approachable, as well as a multitude of cardiovascular applications. In addition, this technique could find application in other interventional techniques, including systemic trauma resuscitation and transplantation cases.

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“…Die eigenen Versuche haben jedoch gezeigt, dal3 bei Anwendung kristalloider und kolloidaler Perfusionsl6sungen die Perfusionsraten w~ihrend der Kt~hlung successiv erh6ht werden k0nnen, so dal3 wesentlich h6here Bypassraten als in der Literatur angegeben, resultieren [1,19,20,29,37,42,57]. Die starke Blutverdt~nnung und die Verbesserung der rheologischen Eigenschaften des Perfusates wirken daher der ffir Hypothermie typischen Umverteilung der Gesamtdurchstr6mung mit regionaler Temperaturdissoziation und Gefahr der Hypoxie [6,8,13,52] entgegen. Die starke Blutverdt~nnung und die Verbesserung der rheologischen Eigenschaften des Perfusates wirken daher der ffir Hypothermie typischen Umverteilung der Gesamtdurchstr6mung mit regionaler Temperaturdissoziation und Gefahr der Hypoxie [6,8,13,52] entgegen.…”

Section: Methodik Des Totalen Blutaustauschesunclassified

“…Da unterhalb 27°C die Viskosit~it yon Blut fiberproportional ansteigt, erfolgte die Retransfusion der Erythrozyten w~ihrend der Wiederauf-w~trmung erst ab Oesophagustemperaturen von 26°C [6,45]. Die in Gruppe IV erh6hte Hfimolyserate ist wahrscheinlich auf die lfingere Lagerungszeit der gewaschenen Erythrozyten zurfickzuffihren.…”

Section: Methodik Des Totalen Blutaustauschesunclassified

Hypothermer Kreislaufstillstand nach totalem Blutaustausch beim Hund

et al. 1978

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Total body washout (hct less than 1%) in hypothermia was performed in 31 dogs using either a crystalloidal or a colloidal perfusate. Blood exchange and cooling was achieved by means of partial bypass and heat exchanger. Short lasting blood exchange for crystalloids without cardiac arrest resulted in 66% survival of the animals. When in addition circulatory arrest was established for 30 min at 14 degrees C oesophageal temperature blood exchange for crystalloids was not tolerated. All four animals of this group died within 19 hours presenting massive interstitial edema. Replacement of the crystalloidal perfusate by a colloidal solution (2.5 g% Dextran 60 at Ringer's Lactate) and establishing circulatory for 30 or 60 min resulted in survival rates of 71% and 50% respectively. The use of the colloidal perfusate effectively prevented edema formation. Death could not be correlated with the parameters controlled.

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Microcirculation During Hypothermia

Cited by 16 publications

References 2 publications

Deterimental effect of prolonged hypothermia in cats and monkeys with and without regional cerebral ischemia.

Deterimental effect of prolonged hypothermia in cats and monkeys with and without regional cerebral ischemia.

Blood Substitution: An Experimental Study

Hypothermer Kreislaufstillstand nach totalem Blutaustausch beim Hund

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