Effects of nifedipine on intracranial pressure in neurosurgical patients with arterial hypertension

1988 ◽  
Vol 69 (2) ◽  
pp. 213-215 ◽  
Author(s):  
Akio Tateishi ◽  
Takanobu Sano ◽  
Hiroshi Takeshita ◽  
Toshihisa Suzuki ◽  
Hisao Tokuno
Keyword(s):  
Intracranial Pressure ◽  
Arterial Hypertension ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Content Type ◽  
Neurological Signs ◽  
Arterial Blood ◽  
Neurosurgical Patients ◽  
The Mean ◽  
Made In

✓ The effects of nifedipine, 20 mg administered via a nasogastric tube, on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were examined. Nifedipine was administered to treat arterial hypertension (> 180 mm Hg, systolic). Ten measurements were made in eight patients with cerebrovascular disease or head trauma. The mean arterial blood pressure (MABP) and ICP were measured before and for 30 minutes after the administration of nifedipine. The MABP gradually decreased and reached its lowest value at approximately 10 minutes after initiation of nifedipine administration, and thereafter remained unchanged. The MABP decreased significantly from 128 ± 8 (mean ± standard deviation) to 109 ± 7 mm Hg, and the CPP decreased from 105 ± 11 to 84 ± 10 mm Hg. The ICP increased by 1 to 10 mm Hg in eight of 10 measurements, and the mean change of ICP from 19 ± 7 to 22 ± 6 mm Hg was statistically significant. These changes were not accompanied by alterations in neurological signs. The results suggest that enteral nifedipine produces a small but statistically significant increase in ICP. Accordingly, neurological signs must be closely observed to detect deterioration, which can be caused by an increase in ICP and/or a decrease in CPP.

Intracranial pressure changes induced by sodium nitroprusside in patients with intracranial mass lesions

1978 ◽  
Vol 48 (3) ◽  
pp. 329-331 ◽  
Author(s):  
James E. Cottrell ◽  
Katie Patel ◽  
Herman Turndorf ◽  
Joseph Ransohoff
Keyword(s):  
Intracranial Pressure ◽  
Sodium Nitroprusside ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Intracranial Tumors ◽  
Cerebral Blood Vessels ◽  
Content Type ◽  
The Mean ◽  
Pressure Changes ◽  
Mass Lesions

✓ Because of the ability of sodium nitroprusside (SNP) to dilate cerebral blood vessels, intracranial pressure (ICP) should increase with its use. In patients with vascular intracranial tumors following SNP (0.01%) infusion, ICP increased from 14.58 ± 1.85 to 27.61 ± 3.33 torr (p > 0.0005) and cerebral perfusion pressure decreased from 89.32 ± 3.5 to 43.23 ± 4.60 torr (p < 0.0005) when the mean arterial pressure had reduced by 33%. These results suggest that SNP not be used in patients with raised ICP unless previous measures have been taken to improve intracranial compliance.

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.

Effects of positive end-expiratory pressure on intracranial pressure in dogs with intracranial hypertension

1981 ◽  
Vol 55 (5) ◽  
pp. 704-707 ◽  
Author(s):  
Jon S. Huseby ◽  
John M. Luce ◽  
Jeffrey M. Cary ◽  
Edward G. Pavlin ◽  
John Butler
Keyword(s):  
Intracranial Pressure ◽  
Intracranial Hypertension ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Autoregulation ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Clinical Situation ◽  
Positive End Expiratory Pressure ◽  
Content Type ◽  
Neurosurgical Patients

✓ Positive end-expiratory pressure (PEEP) is used to improve oxygenation in patients with the adult respiratory distress syndrome. Nevertheless, this treatment may increase intracranial pressure (ICP) and be detrimental to certain neurosurgical patients. This clinical situation was simulated by administering PEEP to dogs with normal and elevated ICP. Increases in PEEP increased ICP in all animals. However, the presence of intracranial hypertension diminished the increase in ICP seen at a given level of PEEP. Cerebral perfusion pressure also fell less in the presence of intracranial hypertension than it did in its absence, although in the former situation cerebral perfusion pressure was at the lower limits of the range of cerebral autoregulation. These findings suggest that PEEP is no more detrimental to patients with elevated ICP than it is to patients whose ICP is normal, assuming that their cerebral autoregulation is not impaired.

Evaluation of a method for noninvasive intracranial pressure assessment during infusion studies in patients with hydrocephalus

2000 ◽  
Vol 92 (5) ◽  
pp. 793-800 ◽  
Author(s):  
Bernhard Schmidt ◽  
Marek Czosnyka ◽  
Jens Jürgen Schwarze ◽  
Dirk Sander ◽  
Werner Gerstner ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Intracranial Pressure ◽  
Time Course ◽  
Cerebral Blood Flow Velocity ◽  
Absolute Error ◽  
Content Type ◽  
Arterial Blood ◽  
Potential Clinical Benefit ◽  
The Mean ◽  
Fine Print

Object. A mathematical model previously introduced by the authors allowed noninvasive intracranial pressure (nICP) assessment. In the present study the authors investigated this model as an aid in predicting the time course of raised ICP during infusion tests in patients with hydrocephalus and its suitability for estimating the resistance to outflow of cerebrospinal fluid (Rcsf).Methods. Twenty-one patients with hydrocephalus were studied. The nICP was calculated from the arterial blood pressure (ABP) waveform by using a linear signal transformation, which was dynamically modified by the relationship between ABP and cerebral blood flow velocity. This model was verified by comparison of nICP with “real” ICP measured during lumbar infusion tests. In all simulations, parallel increases in real ICP and nICP were evident. The simulated Rcsf was computed using nICP and then compared with Rcsf computed from real ICP. The mean absolute error between real and simulated Rcsf was 4.1 ± 2.2 mm Hg minute/ml. By the construction of simulations specific to different subtypes of hydrocephalus arising from various causes, the mean error decreased to 2.7 ± 1.7 mm Hg minute/ml, whereas the correlation between real and simulated Rcsf increased from R = 0.73 to R = 0.89 (p < 0.001).Conclusions. The validity of the mathematical model was confirmed in this study. The creation of type-specific simulations resulted in substantial improvements in the accuracy of ICP assessment. Improvement strategies could be important because of a potential clinical benefit from this method.

Effect of positive end expiratory pressure ventilation on intracranial pressure in man

1977 ◽  
Vol 46 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Michael L. J. Apuzzo ◽  
Martin H. Weiss ◽  
Viesturs Petersons ◽  
R. Baldwin Small ◽  
Theodore Kurze ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Perfusion Pressure ◽  
Venous Pressure ◽  
Blood Gases ◽  
Pulmonary Injury ◽  
Positive End Expiratory Pressure ◽  
Central Venous ◽  
Content Type ◽  
Arterial Blood ◽  
Peep Ventilation

✓ This study was designed to define the effect of positive end expiratory pressure (PEEP) ventilation on intracranial pressure (ICP). In 25 patients with severe head trauma with and without associated pulmonary injury the following parameters were simultaneously monitored under mechanical ventilation with and without PEEP: ICP, arterial blood pressure, central venous pressure, arterial blood gases, and cardiac rate. In addition, the volume-pressure response (VPR) was evaluated in each patient to assess cerebral elastance. The results indicate a significant increase in ICP with the application of PEEP only in the 12 patients who manifested increased cerebral elastance by VPR. Half of this latter group manifested impairment of cerebral perfusion pressure to levels less than 60 mm Hg. Return to baseline ICP levels was observed with termination of PEEP. No significantly consistent changes in other parameters were noted.

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.

Relationship of perfusion pressure and size to risk of hemorrhage from arteriovenous malformations

1992 ◽  
Vol 76 (6) ◽  
pp. 918-923 ◽  
Author(s):  
Robert F. Spetzler ◽  
Ronald W. Hargraves ◽  
Patrick W. McCormick ◽  
Joseph M. Zabramski ◽  
Richard A. Flom ◽  
...  
Keyword(s):  
Perfusion Pressure ◽  
Feeding Artery ◽  
Content Type ◽  
Arterial Blood ◽  
The Mean ◽  
Feeding Pressure ◽  
Risk Of Hemorrhage ◽  
Relationship Of ◽  
The Relationship ◽  
Fine Print

✓ The relationship between the size of an arteriovenous malformation (AVM) and its propensity to hemorrhage is unclear. Although nidus volume increases geometrically with respect to AVM diameter, hemorrhages are at least as common, in small AVM's compared to large AVM's. The authors prospectively evaluated 92 AVM's for nidus size, hematoma size, and arterial feeding pressure to determine if these variables influence the tendency to hemorrhage. Small AVM's (diameter ≤ 3 cm) presented with hemorrhage significantly more often (p < 0.001) than large AVM's (diameter > 6 cm), the incidence being 82% versus 21%. Intraoperative arterial pressures were recorded from the main feeding vessel(s) in 24 of the 92 patients in this series: 10 presented with hemorrhage and 14 presented with other neurological symptoms. In the AVM's that had hemorrhaged, the mean difference between mean arterial blood pressure and the feeding artery pressure was 6.5 mm Hg (range 2 to 15 mm Hg). In the AVM's that did not rupture, this difference was 40 mm Hg (range 17 to 63 mm Hg). Smaller AVM's had significantly higher feeding artery pressures (p < 0.05) than did larger AVM's, and they were associated with large hemorrhages. It is suggested that differences in arterial feeding pressure may be responsible for the observed relationship between the size of AVM's and the frequency and severity of hemorrhage.

scholarly journals Comparison of static and dynamic cerebral autoregulation under anesthesia influence in a controlled animal model

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245291
Author(s):  
Alexander Ruesch ◽  
Deepshikha Acharya ◽  
Samantha Schmitt ◽  
Jason Yang ◽  
Matthew A. Smith ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Animal Model ◽  
Blood Flow ◽  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Autoregulation ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Phase Lag ◽  
Arterial Blood

The brain’s ability to maintain cerebral blood flow approximately constant despite cerebral perfusion pressure changes is known as cerebral autoregulation (CA) and is governed by vasoconstriction and vasodilation. Cerebral perfusion pressure is defined as the pressure gradient between arterial blood pressure and intracranial pressure. Measuring CA is a challenging task and has created a variety of evaluation methods, which are often categorized as static and dynamic CA assessments. Because CA is quantified as the performance of a regulatory system and no physical ground truth can be measured, conflicting results are reported. The conflict further arises from a lack of healthy volunteer data with respect to cerebral perfusion pressure measurements and the variety of diseases in which CA ability is impaired, including stroke, traumatic brain injury and hydrocephalus. To overcome these differences, we present a healthy non-human primate model in which we can control the ability to autoregulate blood flow through the type of anesthesia (isoflurane vs fentanyl). We show how three different assessment methods can be used to measure CA impairment, and how static and dynamic autoregulation compare under challenges in intracranial pressure and blood pressure. We reconstructed Lassen’s curve for two groups of anesthesia, where only the fentanyl anesthetized group yielded the canonical shape. Cerebral perfusion pressure allowed for the best distinction between the fentanyl and isoflurane anesthetized groups. The autoregulatory response time to induced oscillations in intracranial pressure and blood pressure, measured as the phase lag between intracranial pressure and blood pressure, was able to determine autoregulatory impairment in agreement with static autoregulation. Static and dynamic CA both show impairment in high dose isoflurane anesthesia, while low isoflurane in combination with fentanyl anesthesia maintains CA, offering a repeatable animal model for CA studies.

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.

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