scholarly journals Effect of Body Position on Intraocular Pressure (IOP), Intracranial Pressure (ICP), and Translaminar Pressure (TLP) Via Continuous Wireless Telemetry in Nonhuman Primates (NHPs)

2020 ◽  
Vol 61 (12) ◽  
pp. 18
Author(s):  
Jessica V. Jasien ◽  
Brian C. Samuels ◽  
James M. Johnston ◽  
J. Crawford Downs
Keyword(s):  
Intraocular Pressure ◽  
Intracranial Pressure ◽  
Nonhuman Primates ◽  
Body Position ◽  
Wireless Telemetry

scholarly journals Cyclic Pattern of Intraocular Pressure (IOP) and Transient IOP Fluctuations in Nonhuman Primates Measured with Continuous Wireless Telemetry

2019 ◽  
Vol 44 (11) ◽  
pp. 1244-1252 ◽  
Author(s):  
Jessica V. Jasien ◽  
Daniel C. Turner ◽  
Christopher A. Girkin ◽  
J. Crawford Downs
Keyword(s):  
Intraocular Pressure ◽  
Nonhuman Primates ◽  
Cyclic Pattern ◽  
Wireless Telemetry

Author Response: Retinal Vein Pulsation Is in Phase with Intracranial Pressure and Not Intraocular Pressure

2012 ◽  
Vol 53 (11) ◽  
pp. 6880 ◽  
Author(s):  
William H. Morgan ◽  
Christopher R. P. Lind ◽  
Samuel Kain ◽  
Naeem Fatehee ◽  
Arul Bala ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Intracranial Pressure ◽  
Author Response

Abstract 114: Effect of Body Position on Intracranial Pressure and Carotid Blood Flow During Extracorporeal Cardiopulmonary Resuscitation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_4) ◽  
Author(s):  
Yaël Levy ◽  
Rocio Fernandez ◽  
Fanny Lidouren ◽  
Matthias Kohlhauer ◽  
Lionel Lamhaut ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Arrest ◽  
Intracranial Pressure ◽  
Cardiopulmonary Resuscitation ◽  
Body Position ◽  
Spontaneous Circulation ◽  
Systemic Hemodynamics ◽  
Body Tilt ◽  
Whole Body ◽  
Extracorporeal Cardiopulmonary Resuscitation

Introduction: Extracorporeal cardiopulmonary resuscitation (E-CPR) using extracorporeal membrane oxygenation (ECMO) is widely proposed for the treatment of refractory cardiac arrest. Hypothesis: Since cerebral autoregulation is altered in such conditions, body position may modify hemodynamics during ECPR. Our goal was to determine whether a whole body tilt-up challenge (TUC) could lower intracranial pressure (ICP) as previously shown with conventional CPR, without deteriorating cerebral blood flow (CBF). Methods: Pigs were anesthetized and instrumented for the continuous evaluation of CBF, ICP and systemic hemodynamics. After 15 min of untreated ventricular fibrillation they were treated with 30 min of E-CPR followed by sequential defibrillation shocks until resumption of spontaneous circulation (ROSC). ECMO was continued after ROSC to target a mean arterial pressure (MAP) >60 mmHg. Animals were maintained in the flat position (FP) throughout protocol, except during a 2 min TUC of the whole body (+30°) at baseline, during E-CPR and after-ROSC. Results: Four animals received the entire procedure and ROSC was obtained in 3/4. After cardiac arrest, E-CPR was delivered at 29±2 ml/kg/min to maintain a MAP of 57±8 mmHg in the FP. CBF was 28% of baseline and ICP remain stable (12±1 vs 13±1 mmHg during ECPR vs baseline, respectively). Under baseline pre-arrest conditions TUC resulted in a significant decrease in ICP (-63±7%) and CBF (-21±3%) versus the FP, with no significant effect on systemic hemodynamics. During E-CPR and after ROSC, TUC markedly reduced ICP but CBF remained unchanged vs the FP (Figure). Conclusion: During E-CPR whole body TUC reduced ICP without lowering CBF compared with E-CPR flat. Additional investigations with prolonged TUC and selective head and thorax elevation during E-CPR are warranted.

scholarly journals Acute Stress Increases Intraocular Pressure in Nonhuman Primates

2019 ◽  
Vol 2 (4) ◽  
pp. 210-214 ◽  
Author(s):  
Daniel C. Turner ◽  
Michelle Miranda ◽  
Jeffrey S. Morris ◽  
Christopher A. Girkin ◽  
J. Crawford Downs
Keyword(s):  
Intraocular Pressure ◽  
Nonhuman Primates ◽  
Acute Stress

scholarly journals Accuracy of Noninvasive Intraocular Pressure or Optic Nerve Sheath Diameter Measurements for Predicting Elevated Intracranial Pressure in Cryptococcal Meningitis

2014 ◽  
Vol 1 (3) ◽  
Author(s):  
Henry W. Nabeta ◽  
Nathan C. Bahr ◽  
Joshua Rhein ◽  
Nicholas Fossland ◽  
Agnes N. Kiragga ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Optic Nerve ◽  
Intracranial Pressure ◽  
Cryptococcal Meningitis ◽  
Optic Nerve Sheath Diameter ◽  
Diagnostic Value ◽  
Optic Nerve Sheath ◽  
Increased Intracranial Pressure ◽  
Nerve Sheath ◽  
Immunodeficiency Virus

Abstract Background.  Cryptococcal meningitis is associated with increased intracranial pressure (ICP). Therapeutic lumbar puncture (LP) is recommended when the initial ICP is >250 mm H2O, yet the availability of manometers in Africa is limited and not always used where available. We assessed whether intraocular pressure could be a noninvasive surrogate predictor to determine when additional therapeutic LPs are necessary. Methods.  Ninety-eight human immunodeficiency virus-infected Ugandans with suspected meningitis (81% Cryptococcus) had intraocular pressure measured using a handheld tonometer (n = 78) or optic nerve sheath diameter (ONSD) measured by ultrasound (n = 81). We determined the diagnostic performance of these methods for predicting ICP vs a standard manometer. Results.  The median ICP was 225 mm H2O (interquartile range [IQR], 135–405 mm H2O). The median intraocular pressure was 28 mm Hg (IQR, 22–37 mm Hg), and median ultrasound ONSD was 5.4 mm (IQR, 4.95–6.1 mm). ICP moderately correlated with intraocular pressure (ρ = 0.45, P < .001) and with ultrasound ONSD (ρ = 0.44, P < .001). There were not discrete threshold cutoff values for either tonometry or ultrasound ONSD that provided a suitable cutoff diagnostic value to predict elevated ICP (>200 mm H2O). However, risk of elevated ICP >200 mm H2O was increased with an average intraocular pressure >28 mm Hg (relative risk [RR] = 3.03; 95% confidence interval [CI], 1.55–5.92; P < .001) or an average of ONSD >5 mm (RR = 2.39; 95% CI, 1.42–4.03; P = .003). As either intraocular pressure or ONSD increased, probability of elevated ICP increased (ie, positive predictive value increased). Conclusions.  Noninvasive intraocular pressure measurements by tonometry or ultrasound correlate with cerebrospinal fluid opening pressure, but both are a suboptimal replacement for actual ICP measurement with a manometer.

scholarly journals About interrelation of intracranial pressure and cerebral blood flow when positioning at patients with acute brain damage

2019 ◽  
Vol 18 (4) ◽  
pp. 4-10
Author(s):  
V. I. Gorbachev ◽  
N. V. Bragina ◽  
S. V. Gorbachev
Keyword(s):  
Blood Flow ◽  
Intensive Care ◽  
Cerebral Blood Flow ◽  
Intracranial Pressure ◽  
Brain Damage ◽  
Perfusion Pressure ◽  
Body Position ◽  
Slope Angle ◽  
Cerebral Damage ◽  
Bed Position

Changing of «head – of – the bed» position is a routine method of positioning the patient to correct intracranial hypertension. In intensive care units, the «head – of – the bed» position vary from 0 to 60 °, and there is no consensus on which of them is most effective. The review of the major publications in the domestic and foreign literature about the problem of interrelation between positioning and changes of intracranial pressure, system and cerebral hemodynamic in patients with brain damage including databases eLibrary, PubMed, with the key words «hyperthermia», « positioning», «slope angle of the head of bed», «intracranial pressure», «cerebral perfusion pressure», «cerebral blood flow», «brain damage», and their combination. It is believed that the majority of patients with cerebral damage, regardless of the etiological factor, is preferable to 15–30° «head – of – the bed» position. In some cases manipulation of the head of the bed can lead to irreversible ischemic damage, due to the reduction of system and perfusion pressure, and cerebral blood flow. Thus, the selection of the optimal body position in acute cerebral pathology remains a debated issue. In this way, individual tactics of positioning in patients with cerebral damage allows choosing the correct intensive care and improving the treatment results.

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