Intracranial pressure in nontraumatic ischemic and hypoxic cerebral insults

1981 ◽  
Vol 54 (4) ◽  
pp. 489-493 ◽  
Author(s):  
Howard J. Senter ◽  
Aizik Wolf ◽  
Franklin C. Wagner
Keyword(s):  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Content Type ◽  
Effect Of Treatment ◽  
Cerebral Insult ◽  
Salvage Rate ◽  
Increased Icp ◽  
Fine Print

✓ Intracranial pressure (ICP) and cerebral perfusion pressure were monitored in 12 patients who were comatose secondary to hypoxic (five cases) or hypotensive (seven cases) nontraumatic cerebral insults. Patients who were hypotensive but not hypoxic developed significant increased ICP. In patients who were comatose from hypoxic cerebral insults without hypotension, ICP was normal. When an increase in ICP was diagnosed, patients were managed aggressively so as to improve cerebral perfusion and lower ICP. Although a functional salvage rate of 25% was obtained, this may reflect the severity of the initial cerebral insult rather than the effect of treatment. In order to prevent the potential deleterious effects of raised ICP, it is concluded that monitoring ICP and maintaining adequate perfusion may be warranted in comatose patients who have suffered nontraumatic diffuse ischemic but not purely hypoxic cerebral insults.

Cerebral perfusion pressure, intracranial pressure, and head elevation

1986 ◽  
Vol 65 (5) ◽  
pp. 636-641 ◽  
Author(s):  
Michael J. Rosner ◽  
Irene B. Coley
Keyword(s):  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Pressure Waves ◽  
Content Type ◽  
Arterial Blood ◽  
Head Elevation ◽  
Adequate Hydration ◽  
Fine Print

✓ Previous investigations have suggested that intracranial pressure waves may be induced by reduction of cerebral perfusion pressure (CPP). Since pressure waves were noted to be more common in patients with their head elevated at a standard 20° to 30°, CPP was studied as a function of head position and its effect upon intracranial pressure (ICP). In 18 patients with varying degrees of intracranial hypertension, systemic arterial blood pressure (SABP) was monitored at the level of both the head and the heart. Intracranial pressure and central venous pressure were assessed at every 10° of head elevation from 0° to 50°. For every 10° of head elevation, the average ICP decreased by 1 mm Hg associated with a reduction of 2 to 3 mm Hg CPP. The CPP was not beneficially affected by any degree of head elevation. Maximal CPP (73 ± 3.4 mm Hg (mean ± standard error of the mean)) always occurred with the head in a horizontal position. Cerebrospinal fluid pressure waves occurred in four of the 18 patients studied as a function of reduced CPP caused by head elevation alone. Thus, elevation of the head of the bed was associated with the development of CPP decrements in all cases, and it precipitated pressure waves in some. In 15 of the 18 patients, CPP was maintained by spontaneous 10- to 20-mm Hg increases in SABP, and pressure waves did not occur if CPP was maintained at 70 to 75 mm Hg or above. It is concluded that 0° head elevation maximizes CPP and reduces the severity and frequency of pressure-wave occurrence. If the head of the bed is to be elevated, then adequate hydration and avoidance of pharmacological agents that reduce SABP or prevent its rise are required to maximize CPP.

Experimental cerebral oligemia and ischemia produced by intracranial hypertension

1975 ◽  
Vol 43 (3) ◽  
pp. 318-322 ◽  
Author(s):  
Lawrence F. Marshall ◽  
David I. Graham ◽  
Felix Durity ◽  
Robert Lounsbury ◽  
Frank Welsh ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Intracranial Pressure ◽  
Intracranial Hypertension ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Raised Intracranial Pressure ◽  
Content Type ◽  
Complete Cerebral Ischemia ◽  
Fine Print

✓ The authors studied the morphological sequelae of 15 minutes of cerebral oligemia (20 torr cerebral perfusion pressure) and complete cerebral ischemia produced by raised intracranial pressure in rabbits. Ischemic cell change was present in five of seven ischemic animals; it was most extensive in the striatum and hippocampus, with only a few ischemic nerve cells in the thalamus and neocortex. The brains of control and oligemic animals were normal. These results indicate the following: 1) ischemia is a more severe insult than oligemia; 2) compression ischemia results in a pattern of damage that differs from that produced by other types of ischemia; and 3) the method used to reduce cerebral perfusion pressure is an important factor in determining the pattern and extent of brain damage produced.

Cerebral perfusion pressure in head-injured patients: a noninvasive assessment using transcranial Doppler ultrasonography

1998 ◽  
Vol 88 (5) ◽  
pp. 802-808 ◽  
Author(s):  
Marek Czosnyka ◽  
Basil F. Matta ◽  
Piotr Smielewski ◽  
Peter J. Kirkpatrick ◽  
John D. Pickard
Keyword(s):  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Transcranial Doppler ◽  
Cerebral Perfusion ◽  
Doppler Ultrasonography ◽  
Perfusion Pressure ◽  
Content Type ◽  
Head Injured ◽  
Injured Patients ◽  
Fine Print

Object. The authors studied the reliability of a new method for noninvasive assessment of cerebral perfusion pressure (CPP) in head-injured patients in which mean arterial blood pressure (ABP) and transcranial Doppler middle cerebral artery mean and diastolic flow velocities are measured. Methods. Cerebral perfusion pressure was estimated (eCPP) over periods of continuous monitoring (20 minutes—2 hours, 421 daily examinations) in 96 head-injured patients (Glasgow Coma Scale score < 13) who were admitted to the intensive care unit. All patients were sedated, paralyzed, and ventilated. The eCPP and the measured CPP (ABP minus intracranial pressure, measured using an intraparenchymal microsensor) were compared. The correlation between eCPP and measured CPP was r = 0.73; p < 10−6. In 71% of the examinations, the estimation error was less than 10 mm Hg and in 84% of the examinations, the error was less than 15 mm Hg. The method had a high positive predictive power (94%) for detecting low CPP (< 60 mm Hg). The eCPP also accurately reflected changes in measured CPP over time (r > 0.8; p < 0.001) in situations such as plateau and B waves of intracranial pressure, arterial hypotension, and refractory intracranial hypertension. A good correlation was found between the average measured CPP and eCPP when day-by-day variability was assessed in a group of 41 patients (r = 0.71). Conclusions. Noninvasive estimation of CPP by using transcranial Doppler ultrasonography may be of value in situations in which monitoring relative changes in CPP is required without invasive measurement of intracranial pressure.

Intracranial hypertension and cerebral perfusion pressure: influence on neurological deterioration and outcome in severe head injury

2000 ◽  
Vol 92 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Niels Juul ◽  
Gabrielle F. Morris ◽  
Sharon B. Marshall ◽  
_ _ ◽  
Lawrence F. Marshall
Keyword(s):  
Head Injury ◽  
Intracranial Hypertension ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Severe Head Injury ◽  
Perfusion Pressure ◽  
Neurological Deterioration ◽  
Double Blind ◽  
Content Type ◽  
Fine Print

Object. Recently, a renewed emphasis has been placed on managing severe head injury by elevating cerebral perfusion pressure (CPP), which is defined as the mean arterial pressure minus the intracranial pressure (ICP). Some authors have suggested that CPP is more important in influencing outcome than is intracranial hypertension, a hypothesis that this study was designed to investigate.Methods. The authors examined the relative contribution of these two parameters to outcome in a series of 427 patients prospectively studied in an international, multicenter, randomized, double-blind trial of the N-methyl-d-aspartate antagonist Selfotel. Mortality rates rose from 9.6% in 292 patients who had no clinically defined episodes of neurological deterioration to 56.4% in 117 patients who suffered one or more of these episodes; 18 patients were lost to follow up. Correspondingly, favorable outcome, defined as good or moderate on the Glasgow Outcome Scale at 6 months, fell from 67.8% in patients without neurological deterioration to 29.1% in those with neurological deterioration. In patients who had clinical evidence of neurological deterioration, the relative influence of ICP and CPP on outcome was assessed. The most powerful predictor of neurological worsening was the presence of intracranial hypertension (ICP ≥ 20 mm Hg) either initially or during neurological deterioration. There was no correlation with the CPP as long as the CPP was greater than 60 mm Hg.Conclusions. Treatment protocols for the management of severe head injury should emphasize the immediate reduction of raised ICP to less than 20 mm Hg if possible. A CPP greater than 60 mm Hg appears to have little influence on the outcome of patients with severe head injury.

Hyperacute measurement of intracranial pressure, cerebral perfusion pressure, jugular venous oxygen saturation, and laser Doppler flowmetry, before and during removal of traumatic acute subdural hematoma

2001 ◽  
Vol 95 (4) ◽  
pp. 569-572 ◽  
Author(s):  
Bon H. Verweij ◽  
J. Paul Muizelaar ◽  
Federico C. Vinas
Keyword(s):  
Intracranial Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Laser Doppler ◽  
Bone Flap ◽  
Acute Subdural Hematoma ◽  
Laser Doppler Flow ◽  
Content Type ◽  
Venous Oxygen Saturation ◽  
Fine Print

Object. The poor prognosis for traumatic acute subdural hematoma (ASDH) might be due to underlying primary brain damage, ischemia, or both. Ischemia in ASDH is likely caused by increased intracranial pressure (ICP) leading to decreased cerebral perfusion pressure (CPP), but the degree to which these phenomena occur is unknown. The authors report data obtained before and during removal of ASDH in five cases. Methods. Five patients who underwent emergency evacuation of ASDH were monitored. In all patients, without delaying treatment, a separate surgical team (including the senior author) placed an ICP monitor and a jugular bulb catheter, and in two patients a laser Doppler probe was placed. The ICP prior to removing the bone flap in the five patients was 85, 85, 50, 59, and greater than 40 mm Hg, resulting in CPPs of 25, 3, 25, 56, and less than 50 mm Hg, respectively. Removing the bone flap as well as opening the dura and removing the blood clot produced a significant decrease in ICP and an increase in CPP. Jugular venous oxygen saturation (SjvO2) increased in four patients and decreased in the other during removal of the hematoma. Laser Doppler flow also increased, to 217% and 211% compared with preevacuation flow. Conclusions. Intracranial pressure is higher than previously suspected and CPP is very low in patients with ASDH. Removal of the bone flap yielded a significant reduction in ICP, which was further decreased by opening the dura and evacuating the hematoma. The SjvO2 as well as laser Doppler flow increased in all patients but one immediately after removal of the hematoma.

Effect of reduced cerebral perfusion pressure on cerebral blood flow following inhibition of nitric oxide synthesis

1998 ◽  
Vol 89 (3) ◽  
pp. 448-453 ◽  
Author(s):  
Ingunn R. Rise ◽  
Ole J. Kirkeby
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Intracranial Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Nitric Oxide Synthesis ◽  
Content Type ◽  
Cerebrovascular Resistance ◽  
Fine Print

Object. The authors tested the hypothesis in a porcine model that inhibition of nitric oxide synthesis during reduced cerebral perfusion pressure (CPP) affected the relative cerebral blood flow (CBF) and the cerebrovascular resistance. Methods. The CPP was reduced by inducing high cerebrospinal fluid pressure and hemorrhagic hypotension. With continuous blood and intracranial pressure monitoring, relative CPP was estimated using the laser Doppler flowmetry technique in nine pigs that received 40 mg/kg nitro-l-arginine methyl ester (l-NAME) and in nine control animals. The l-NAME caused a decrease in relative CBF (p < 0.01) and increases in cerebrovascular resistance (p < 0.01), blood pressure (p < 0.05), and CPP (p < 0.001). During high intracranial pressure there were no significant differences between the treated animals and the controls. After hemorrhage, there was no significant difference between the groups initially, but 30 minutes later the cerebrovascular resistance was decreased in the control group and increased in the l-NAME group relative to baseline (p < 0.05). Combined hemorrhage and high intracranial pressure increased the difference between the two groups with regard to cerebrovascular resistance (p < 0.05). Conclusions. These results suggest that nitric oxide synthesis inhibition affects the autoregulatory response of the cerebral circulation after cardiovascular compensation has taken place. Nitric oxide synthesis inhibition enhanced the undesirable effects of high intracranial pressure during hypovolemia.

Pressure reactivity as a guide in the treatment of cerebral perfusion pressure in patients with brain trauma

2005 ◽  
Vol 102 (2) ◽  
pp. 311-317 ◽  
Author(s):  
Tim Howells ◽  
Kristin Elf ◽  
Patricia A. Jones ◽  
Elisabeth Ronne-Engström ◽  
Ian Piper ◽  
...  
Keyword(s):  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Regression Line ◽  
Brain Trauma ◽  
Treatment Protocols ◽  
Content Type ◽  
Arterial Blood ◽  
Pressure Reactivity ◽  
Fine Print

Object. The aim of this study was to compare the effects of two different treatment protocols on physiological characteristics and outcome in patients with brain trauma. One protocol was primarily oriented toward reducing intracranial pressure (ICP), and the other primarily on maintaining cerebral perfusion pressure (CPP). Methods. A series of 67 patients in Uppsala were treated according to a protocol aimed at keeping ICP less than 20 mm Hg and, as a secondary target, CPP at approximately 60 mm Hg. Another series of 64 patients in Edinburgh were treated according to a protocol aimed primarily at maintaining CPP greater than 70 mm Hg and, secondarily, ICP less than 25 mm Hg for the first 24 hours and 30 mm Hg subsequently. The ICP and CPP insults were assessed as the percentage of monitoring time that ICP was greater than or equal to 20 mm Hg and CPP less than 60 mm Hg, respectively. Pressure reactivity in each patient was assessed based on the slope of the regression line relating mean arterial blood pressure (MABP) to ICP. Outcome was analyzed at 6 months according to the Glasgow Outcome Scale (GOS). The prognostic value of secondary insults and pressure reactivity was determined using linear methods and a neural network. In patients treated according to the CPP-oriented protocol, even short durations of CPP insults were strong predictors of death. In patients treated according to the ICP-oriented protocol, even long durations of CPP insult—mostly in the range of 50 to 60 mm Hg—were significant predictors of favorable outcome (GOS Score 4 or 5). Among those who had undergone ICP-oriented treatment, pressure-passive patients (MABP/ICP slope ≥ 0.13) had a better outcome. Among those who had undergone CPP-oriented treatment, the more pressure-active (MABP/ICP slope < 0.13) patients had a better outcome. Conclusions. Based on data from this study, the authors concluded that ICP-oriented therapy should be used in patients whose slope of the MABP/ICP regression line is at least 0.13, that is, in pressure-passive patients. If the slope is less than 0.13, then hypertensive CPP therapy is likely to produce a better outcome.

Experience with Althesin in the management of persistently raised ICP following severe head injury

1986 ◽  
Vol 64 (3) ◽  
pp. 414-419 ◽  
Author(s):  
Ross Bullock ◽  
James R. van Dellen ◽  
Derek Campbell ◽  
Ian Osborn ◽  
S. Gustav Reinach
Keyword(s):  
Patient Outcome ◽  
Head Injury ◽  
Intracranial Pressure ◽  
Cerebral Perfusion ◽  
Severe Head Injury ◽  
Perfusion Pressure ◽  
Surgical Decompression ◽  
Icp Monitoring ◽  
Content Type ◽  
Fine Print

✓ Of 243 patients who underwent intracranial pressure (ICP) monitoring after severe head injury, 42 (17%) were found to have severe persistently raised ICP, in spite of hyperventilation, mannitol, and surgical decompression. Althesin was infused to reduce ICP in these patients. This agent was shown to be effective and safe in reducing ICP, and a significant improvement in cerebral perfusion pressure was demonstrated. In this respect, Althesin may be more effective than barbiturates. However, no improvement in patient outcome was demonstrated in this series.

Increase in extracellular glutamate caused by reduced cerebral perfusion pressure and seizures after human traumatic brain injury: a microdialysis study

1998 ◽  
Vol 89 (6) ◽  
pp. 971-982 ◽  
Author(s):  
Paul Vespa ◽  
Mayumi Prins ◽  
Elizabeth Ronne-Engstrom ◽  
Michael Caron ◽  
Ehud Shalmon ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Cerebral Microdialysis ◽  
Extracellular Glutamate ◽  
Content Type ◽  
The Mean ◽  
Fine Print

Object. To determine the extent and duration of change in extracellular glutamate levels after human traumatic brain injury (TBI), 17 severely brain injured adults underwent implantation of a cerebral microdialysis probe and systematic sampling was conducted for 1 to 9 days postinjury. Methods. A total of 772 hourly microdialysis samples were obtained in 17 patients (median Glasgow Coma Scale score 5 ± 2.5, mean age 39.4 ± 20.4 years). The mean (± standard deviation) glutamate levels in the dialysate were evaluated for 9 days, during which the mean peak concentration reached 25.4 ± 13.7 (µM on postinjury Day 3. In each patient transient elevations in glutamate were seen each day. However, these elevations were most commonly seen on Day 3. In all patients there was a mean of 4.5 ± 2.5 transient elevations in glutamate lasting a mean duration of 4.4 ± 4.9 hours. These increases were seen in conjunction with seizure activity. However, in many seizure-free patients the increase in extracellular glutamate occurred when cerebral perfusion pressure was less than 70 mm Hg (p < 0.001). Given the potential injury-induced uncoupling of cerebral blood flow and metabolism after TBI, these increases in extracellular glutamate may reflect a degree of enhanced cellular crisis, which in severe head injury in humans appears to last up to 9 days. Conclusions. Extracellular neurochemical measurements of excitatory amino acids may provide a marker for secondary insults that can compound human TBI.

scholarly journals Left or right, up or down: A case for positioning of unconcious head-injured patients

Curationis ◽  
1992 ◽  
Vol 15 (1) ◽  
Author(s):  
M. Hugo
Keyword(s):  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Nursing Care ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Negative Influence ◽  
Head Injured ◽  
Pressure Changes ◽  
Injured Patients ◽  
Increased Icp

Nursing care activities have been proved to cause increases in intracranial pressure (ICP) which could be detrimental to the patient’s health. Because positioning is one of the activities that causes the greatest pressure changes it was evaluated in this study. Cumulative increases also occur when nursing care activities are carried out in quick succession. The analysis of the data and literature suggest that the backrest position with the head of the bed elevated 30 to 45 degrees is the best position for a patient with increased ICP. If further research should prove that this position has a negative influence on the cerebral perfusion pressure, these recommendations will have to be revised.

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