ICP více než jen číslo? MUDr. Josef Škola XXV. kongres ČSARIM, Praha, 4. října 2018

základní koncept ICP jako číslo ICP jako křivka ICP jako nástroj

KONCEPT ICP

Monroe Kellie doctrine (1783)

Normální situace ICP je determinován: polohou těla průtokem krve mozkem (CBF) rychlostí tvorby mozkomíšního moku (CSF) rezistencí toku CSF Davsonova rovnice: ICP = tlak v sinus sagitalis x rychlost tvorby CSF x rezistence toku CSF ICP = 5 až 8 mmhg x 0,3 až 0,4 ml/min x 6 až 10 mmhg/ml/min

Fig. 9.1 Pressure volume curve. Note that in the normal range, towards the origin of the x-axis (point a), intracranial pressure remains normal in spite of small additions of volume until a point of decompensation (point b) occurs. After this, each subsequent increment in volume results in an even larger increment in intracranial pressure (point c). Chapter: Intracranial pressure monitoring Author(s): Federico Villa and Giuseppe Citerio From: Oxford Textbook of Neurocritical Care Downloaded from Oxford Medicine Online.Reproduced with permission from Citerio G. ICP Monitoring in Encyclopedia of Intensive Care Medicine, Vincent JL, Hall JB eds. Springer Verlag Ed 2012.

ICP JAKO ČÍSLO

CPP < 50 mmhg CPP > 50 mmhg

Pasivní autoregulace Aktivní autoregulace

ICP JAKO KŘIVKA

ICP amplituda

Fig. 9.1 Pressure volume curve. Note that in the normal range, towards the origin of the x-axis (point a), intracranial pressure remains normal in spite of small additions of volume until a point of decompensation (point b) occurs. After this, each subsequent increment in volume results in an even larger increment in intracranial pressure (point c). Chapter: Intracranial pressure monitoring Author(s): Federico Villa and Giuseppe Citerio From: Oxford Textbook of Neurocritical Care Downloaded from Oxford Medicine Online.Reproduced with permission from Citerio G. ICP Monitoring in Encyclopedia of Intensive Care Medicine, Vincent JL, Hall JB eds. Springer Verlag Ed 2012.

ICP JAKO NÁSTROJ

Fig. 3.4 Cerebral autoregulation. Within the autoregulatory range between 50 and 150 mmhg MAP (x-axis), CBF (y-axis) remains stable. Over this range there is no correlation between pressure and flow, whereas above and below the autoregulatory range there is a degree of correlation of CBF with MAP. Note also that changes in CBV arise secondary to normal autoregulation and that this can be important in the context of elevated ICP. This diagram indicates the potential for CBV changes in normally autoregulating brain areas to affect ICP in the context of reduced intracranial compliance (dashed line). Note that this neglects considerations of blood pressure effects on CBV on injured, poorly regulating brain areas, which can display pressure passive dilatation with increased pressure, rather than vasoconstriction that arises with normal autoregulation. Chapter: Cerebral blood flow physiology, pharmacology, and pathophysiology Author(s): Chandril Chugh and W. Andrew Kofke From: Oxford Textbook of Neurocritical Care Downloaded from Oxford Medicine Online.Reprinted from Journal of Clinical Neuroscience, 12, 6, Yam ATet al., Cerebral autoregulation and ageing, pp. 643 646, Copyright 2005, with permission from Elsevier.

Lassen, 1959

Lehké poranění mozku 28% narušená AR (Jünger 1997) Težké poranění mozku 87% narušená AR (Hlatky 2002) Horní limit AR posunut doleva (Hauerberg 1998) Dolní limit AR posunut doprava (Cremer 2004)

Pressure reactivity index (PRx)

Optimální CPP Dolní limit autoregulace Horní limit autoregulace 67 mmhg 95 mmhg

SHRNUTÍ

Shrnutí strategie založené na ICP / CPP obsahují řadu kontroverzí ICP jako biologický signál obsahuje mnohem více informací než pouhá střední hodnota klíčovou roli hraje (bude hrát) automatické zpracování a vizualizace dat

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