520:
Under normal circumstances a MAP between 60 and 160 mmHg and ICP about 10 mmHg (CPP of 50-150 mmHg) sufficient blood flow can be maintained with autoregulation. Although the classic 'autoregulation curve' suggests that CBF is fully stable between these blood pressure values (known also as the
531:
Within the autoregulatory range, as CPP falls there is, within seconds, vasodilation of the cerebral resistance vessels, a fall in cerebrovascular resistance and a rise in cerebral-blood volume (CBV), and therefore CBF will return to baseline value within seconds (see as ref. Aaslid, Lindegaard,
510:
444:
239:, where an external pressure (in this case, the intracranial pressure) causes decreased blood flow through the vessels. In this sense, more specifically, the cerebral perfusion pressure can be defined as either:
536:). These adaptations to rapid changes in blood pressure (in contrast with changes that occur over periods of hours or days) are known as dynamic cerebral autoregulation.
347:
290:
207:
138:
449:
383:
745:
659:
528:
is potentially deadly). In trauma some recommend CPP not go below 70 mmHg. Recommendations in children is at least 60 mmHg.
524:
Outside of the limits of autoregulation, raising MAP raises CBF and raising ICP lowers it (this is one reason that increasing ICP in
804:
710:
366:
562:
38:). It must be maintained within narrow limits because too little pressure could cause brain tissue to become
655:"Cerebral autoregulation: An overview of current concepts and methodology with special focus on the elderly"
838:
605:
70:). While both the blood and CSF have poor compression capacity, the brain is easily compressible.
302:
245:
229:
162:
91:
235:
This definition may be more appropriate if considering the circulatory system in the brain as a
525:
376:
Increased ICP compresses cerebral arteries, causing increased cerebrovascular resistance (CVR).
217:
73:
Every increase of ICP can cause a change in tissue perfusion and an increase in stroke events.
354:
223:
43:
848:
809:
8:
853:
82:
63:
31:
533:
843:
767:
740:
627:
600:
772:
688:
632:
601:"Reduced brain perfusion and cognitive performance due to constitutional hypotension"
581:
370:
236:
814:
762:
754:
678:
668:
622:
614:
571:
505:{\displaystyle ^{70\,{\textrm {mL}}}/_{100\,{\textrm {g}}{\cdot }{\textrm {min}}}}
439:{\displaystyle ^{20\,{\textrm {mL}}}/_{100\,{\textrm {g}}{\cdot }{\textrm {min}}}}
618:
832:
758:
718:
776:
692:
636:
585:
521:
limits of autoregulation), in practice spontaneous fluctuations can occur.
673:
654:
576:
557:
358:
683:
35:
39:
27:
794:
Sanders, MJ; McKenna, K (2001). "Ch. 22: Head and Facial Trauma".
653:
van Beek, AH; Claassen, JA; Rikkert, MG; Jansen, RW (June 2008).
55:
16:
Net pressure gradient causing cerebral blood flow to the brain
652:
67:
59:
58:
encloses a fixed-volume space that holds three components:
42:(having inadequate blood flow), and too much could raise
741:"Monitoring and interpretation of intracranial pressure"
534:
http://stroke.ahajournals.org/cgi/reprint/20/1/45.pdf
452:
386:
305:
248:
165:
94:
704:
702:
81:
CPP can be defined as the pressure gradient causing
746:Journal of Neurology, Neurosurgery, and Psychiatry
504:
438:
341:
284:
201:
132:
711:"Initial evaluation and management of CNS injury"
699:
830:
805:"Intracranial Pressure and Cerebral Blood Flow"
738:
660:Journal of Cerebral Blood Flow & Metabolism
598:
793:
555:
708:
648:
646:
558:"Monitoring the injured brain: ICP and CBF"
151:
357:(ICP) causes decreased blood perfusion of
766:
682:
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626:
575:
551:
549:
480:
460:
414:
394:
802:
365:Increased ICP constitutes an increased
831:
546:
371:driving force for capillary filtration
156:An alternative definition of CPP is:
13:
369:that, in turn, causes a decreased
76:
14:
865:
739:Czosnyka, M; Pickard, JD (2004).
556:Steiner, LA; Andrews, PJ (2006).
515:
373:from intracerebral blood vessels.
367:interstitial hydrostatic pressure
147:CVR is cerebrovascular resistance
66:(CSF), and very soft tissue (the
599:Duschek, S; Schandry, R (2007).
813:(8, Article 4). Archived from
798:(2nd revised ed.). Mosby.
732:
709:Tolias, C; Sgouros, S (2003).
592:
563:British Journal of Anaesthesia
49:
1:
787:
539:
532:Sorteberg, and Nornes 1989:
349:(if JVP is higher than ICP).
7:
606:Clinical Autonomic Research
353:Physiologically, increased
342:{\displaystyle CPP=MAP-JVP}
292:(if ICP is higher than JVP)
285:{\displaystyle CPP=MAP-ICP}
202:{\displaystyle CPP=MAP-ICP}
133:{\displaystyle CBF=CPP/CVR}
20:Cerebral perfusion pressure
10:
870:
796:Mosby's Paramedic Textbook
361:by mainly two mechanisms:
619:10.1007/s10286-006-0379-7
759:10.1136/jnnp.2003.033126
152:By intracranial pressure
230:jugular venous pressure
526:traumatic brain injury
506:
440:
343:
286:
218:mean arterial pressure
203:
134:
803:Walters, FJM (1998).
674:10.1038/jcbfm.2008.13
507:
441:
355:intracranial pressure
344:
287:
224:intracranial pressure
204:
135:
44:intracranial pressure
450:
384:
303:
246:
163:
92:
34:to the brain (brain
839:Medical terminology
446:in white matter to
83:cerebral blood flow
64:cerebrospinal fluid
32:cerebral blood flow
577:10.1093/bja/ael110
502:
436:
380:FLOW Ranging from
339:
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497:
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431:
419:
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237:Starling resistor
30:gradient causing
861:
825:
823:
822:
799:
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780:
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736:
730:
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721:on March 2, 2007
717:. Archived from
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512:in grey matter.
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85:(CBF) such that
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829:
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247:
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164:
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79:
77:From resistance
52:
17:
12:
11:
5:
867:
857:
856:
851:
846:
841:
827:
826:
800:
789:
786:
783:
782:
731:
698:
667:(6): 1071–85.
642:
591:
544:
543:
541:
538:
517:
516:Autoregulation
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491:
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78:
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51:
48:
15:
9:
6:
4:
3:
2:
866:
855:
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850:
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845:
842:
840:
837:
836:
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817:on 2011-05-14
816:
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797:
792:
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774:
769:
764:
760:
756:
753:(6): 813–21.
752:
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742:
735:
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715:Emedicine.com
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57:
47:
45:
41:
37:
33:
29:
26:, is the net
25:
21:
819:. Retrieved
815:the original
808:
795:
750:
744:
734:
723:. Retrieved
719:the original
714:
664:
658:
613:(2): 69–76.
610:
604:
594:
570:(1): 26–38.
567:
561:
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523:
519:
379:
352:
295:
234:
211:
155:
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80:
72:
53:
23:
19:
18:
849:Neurotrauma
359:brain cells
50:Definitions
854:Physiology
833:Categories
821:2011-02-10
810:Physiology
788:References
725:2007-03-19
684:2066/80163
844:Neurology
540:Footnotes
490:⋅
424:⋅
328:−
271:−
188:−
36:perfusion
777:15145991
693:18349877
637:17106628
586:16698860
212:where:
40:ischemic
28:pressure
768:1739058
628:1858602
228:JVP is
222:ICP is
216:MAP is
143:where:
56:cranium
46:(ICP).
775:
765:
691:
635:
625:
584:
68:brain
60:blood
22:, or
773:PMID
689:PMID
633:PMID
582:PMID
54:The
763:PMC
755:doi
679:hdl
669:doi
623:PMC
615:doi
572:doi
496:min
478:100
430:min
412:100
296:or
24:CPP
835::
807:.
771:.
761:.
751:75
749:.
743:.
713:.
701:^
687:.
677:.
665:28
663:.
657:.
645:^
631:.
621:.
611:17
609:.
603:.
580:.
568:97
566:.
560:.
548:^
464:mL
458:70
398:mL
392:20
62:,
824:.
779:.
757::
728:.
695:.
681::
671::
639:.
617::
588:.
574::
484:g
473:/
418:g
407:/
337:P
334:V
331:J
325:P
322:A
319:M
316:=
313:P
310:P
307:C
280:P
277:C
274:I
268:P
265:A
262:M
259:=
256:P
253:P
250:C
197:P
194:C
191:I
185:P
182:A
179:M
176:=
173:P
170:P
167:C
128:R
125:V
122:C
118:/
114:P
111:P
108:C
105:=
102:F
99:B
96:C
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