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Anthony Marmarou, Kenneth Shulman, and James LaMorgese

O ur understanding of intracranial pressure (ICP) dynamics has led us to believe that compliance, as defined by the volume pressure curve, and the resistance to fluid absorption are the major parameters that control the rate of change and resting level of the ICP. This report describes the methods used in dealing with the nonlinear compliance of the cerebrospinal fluid (CSF) space and its relation to pressure, with emphasis on special techniques for rapid determination of both compliance and absorption resistance. These methods are then used to evaluate the

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Noninvasive intracranial compliance monitoring

Technical note and clinical results

Erhard W. Lang, Klaus Paulat, Christoph Witte, Jürgen Zolondz, and H. Maximilian Mehdorn

T he ICC curve represents the pressure—volume relationship of the brain based on the principles of the so-called Monro—Kellie doctrine. 11, 16 It is an indicator of the brain's ability to tolerate or compensate for volume increases or its volume-buffering capacity. Traditionally, this curve has been derived from the volume—pressure response, or the PVI, in which a certain fluid volume is manually injected into the ventricles and the change in ICP is recorded. 14, 15, 30, 31 More recently, an automated pneumatic compliance measurement device integrated into

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Claudia S. Robertson, Raj K. Narayan, Charles F. Contant, Robert G. Grossman, Ziya L. Gokaslan, Rajesh Pahwa, Pedro Caram Jr., Robert S. Bray Jr., and Arthur M. Sherwood

many secondary injury processes. Intracranial compliance has been proposed as an earlier, more sensitive indicator of impending neurological deterioration due to cerebral edema or mass lesions. 22 Volume-pressure response (VPR), which is the change in ICP after injection or withdrawal of 1 ml of cerebrospinal fluid (CSF) over 1 second, is a simple method of expressing intracranial compliance. A normal VPR is less than 2 mm Hg/ml. 15 A VPR of greater than 5 mm Hg/ml indicates a critical reduction in the volume-buffering capacity of the brain. 15 Pressure

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Harold A. Wilkinson, Nancy Schuman, and John Ruggiero

Q uantitative measurements of cerebral compliance, or measurements of the extended and seemingly more accurate parameter, cerebral reactivity, 14, 15 are becoming increasingly accepted in clinical neurosurgery as a means of amplifying the value of direct intracranial pressure (ICP) measurements. These measurements seem to be particularly useful in differentiating when “a normal ICP is in fact a safe ICP” 3 by estimating the volume-pressure response of the brain in a given clinical situation. Measurements of compliance or cerebral reactivity attempt to

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Yun-Hom Yau, Ian R. Piper, Richard E. Clutton, and Ian R. Whittle

) involves the use of an air-filled balloon catheter to measure ICP and is capable of automatic zero-drift correction in vivo. A newer version of the Spiegelberg monitoring system also has the capacity to measure intracranial compliance. In laboratory bench tests the Spiegelberg ICP system has been found to be accurate and to have the lowest zero-drift characteristics compared with currently adopted catheter-tip systems. 3 However, the Spiegelberg system has yet to be tested in vivo against gold-standard methods or devices for measuring ICP in the intraventricular and

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Shahid Shafi, Sunni A. Barnes, D Millar, Justin Sobrino, Rustam Kudyakov, Candice Berryman, Nadine Rayan, Rosemary Dubiel, Raul Coimbra, Louis J. Magnotti, Gary Vercruysse, Lynette A. Scherer, Gregory J. Jurkovich, and Raminder Nirula

developed to improve clinical practices ( http://www.east.org/resources/treatment-guidelines ). 4 In fact, the Centers for Medicare and Medicaid Services (CMS) and the Joint Commission for Accreditation of Health Care Organizations now require compliance with several EBM protocols as quality measures, such as congestive heart failure and surgical care ( http://www.medicare.gov/hospitalcompare/search.html ). Despite these efforts, compliance with several evidence-based processes of care (POCs) remains just over 50%. 7 , 8 , 11 Traumatic brain injury (TBI) is the leading

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Melvin M. Newman, Marta Kligerman, and Mary Willcox

P ulmonary hypertension, pulmonary edema, and decreased pulmonary compliance can result from intracranial pressure (ICP) not exceeding 30 mm Hg in the cat. This chain of events appears to be the result of pulmonary vascular constriction, and is not the result of back pressure from left ventricular failure. Few reported experimental studies have focused on relatively low ICP's (30 to 40 mm Hg) such as are commonly found in patients after head injury or stroke. Most clinical and laboratory studies have followed the pattern set by Harvey Cushing in 1901, who

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Elizabeth A. M. Frost

neurosurgical patient who may be dehydrated following diuretic administration, which would result in decrease of cerebral perfusion pressure. Were these changes to occur, they would clearly be detrimental to the already compromised brain. Initial laboratory studies done in cats demonstrated no significant increase in ICP with increasing PEEP. 7 The following study examines the effect of incremental changes in PEEP on ICP at different values for intracranial compliance in man. Clinical Material and Method In seven comatose patients, ranging in age from 20 to 70 years

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Robert J. Hariri, Andrew D. Firlick, Scott R. Shepard, Douglas S. Cohen, Philip S. Barie, John M. Emery III, and Jamshid B. G. Ghajar

replacement in conjunction with subsequent transfusion of blood. The electrophysiological basis for this was demonstrated by Shires and colleagues, 4, 27, 28 who showed that, in order to restore the cell membrane potential difference and repair the sodium-potassium pump, volume expansion with balanced salt solutions such as Ringer's lactate solution often requires administration of approximately four times the volume of blood lost through hemorrhage. Recently, we reported that quantitatively similar resuscitation correlates with decreased brain compliance in normal

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Cerebrospinal fluid conductance and compliance of the craniospinal space in normal-pressure hydrocephalus

A comparison between two methods for measuring conductance to outflow

Svend Erik Børgesen, Flemming Gjerris, and Søren Claus Sørensen

, the latter method allowed us to obtain an estimate of the compliance of the craniospinal space (C css ). The B-waves in the pressure recording are most probably the result of variations in cerebral vascular volume, and the greater frequency of these pressure variations in certain pathological states, such as NPH, 2, 4 might indicate that the pressure response to changes in cerebral vascular volume is exaggerated. We have also examined whether the frequency of B-waves in these patients might be correlated to C out and/or C css . Clinical Material and Methods