Alterations of Conjunctival Microcirculation in Brain Dead Patients

Study hypothesize that ocular microcirculation is reflecting cerebral perfusion. The purpose of this study is to evaluate ocular microcirculation in brain dead patients using side dark field (SDF) videomicroscope and compare it with microcirculatory parameters of healthy volunteers.

Study Overview

• Status: Completed
• Conditions: Brain Death

Detailed Description

Microcirculation videomicroscopy techniques are used to evaluate a global organ perfusion in various critical conditions using limited suitable sites available for visualisation. However, ocular microcirculation may become a window to specifically cerebral perfusion due to related blood supply, close anatomical proximity and easy accessibility for videomicroscopy. Cerebral perfusion mainly depends on cerebral flow and intracranial pressure and therefore we aim, for the first time, to demonstrate microcirculatory status of ocular conjunctiva in clinical conditions when cerebral flow is completely absent.

In a single center open label observational study investigators analyzed conjunctival and sublingual microcirculation using SDF videomicroscopy in brain dead patients after reaching systemic hemodynamic targets to optimise perfusion of donor organs. All brain death diagnoses were confirmed by cerebral angiography. Microcirculatory images obtained and analyzed using standardized published recommendations by experts in this field. Microcirculation of sublingual and conjunctival areas were recorded in matching number of healthy volunteers using same techniques.

• Study Type: Observational
• Enrollment (Actual): 22

Contacts and Locations

Study Locations

• Lithuania
  • Kaunas, Lithuania
    • Lithuanian University of Health Sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

All single center tertiary level Neurosurgery Intensive Care unit patients angiographically confirmed brain dead.

Description

Inclusion Criteria:

• Diagnosed brain dead

Exclusion Criteria:

• Conjunctival or sublingual mucosa damage

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Brain dead patients; Brain dead patients certified by cerebral angiography.
Healthy volunteers; Any person with no known cerebral pathology.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Microvascular flow index (MFI) of ocular conjunctiva.	Conjunctival convective oxygen transport presented as MFI of small vessels mostly capillaries with diameter cutoff value of 20µm. Images of microcirculation were taken from at least three different points in each ocular conjunctiva and recorded for at least 20 seconds avoiding pressure artifacts. Microcirculation images were obtained using SDF videomicroscopy (Microscan®, Microvision Medicals, Amsterdam, Netherlands). Data recorded to the hard drive of personal computer using AVA 3.0v software (Microvision Medical, Amsterdam, Netherlands). Video clips were then randomly blinded and later analyzed by 2 independent investigators.	After confirmed diagnosis of brain death of any course using cerebral angiography at any time up to 24 hours.
Total vessel density (TVD) of ocular concunctiva.	Conjunctival microvascular diffusion distance presented as TVD (mm/mm²) of small vessels mostly capillaries with diameter cutoff value of 20µm. Images of microcirculation were taken from at least three different points in each ocular conjunctiva and recorded for at least 20 seconds avoiding pressure artifacts. Microcirculation images were obtained using SDF videomicroscopy (Microscan®, Microvision Medicals, Amsterdam, Netherlands). Data recorded to the hard drive of personal computer using AVA 3.0v software (Microvision Medical, Amsterdam, Netherlands). Video clips were then randomly blinded and later analyzed by 2 independent investigators.	After confirmed diagnosis of brain death of any course using cerebral angiography at any time up to 24 hours.
Perfused vessel density (PVD) of ocular conjunctiva.	Conjunctival microvascular diffusion distance presented as PVD (mm/mm²) of small vessels mostly capillaries with diameter cutoff value of 20µm. Images of microcirculation were taken from at least three different points in each ocular conjunctiva and recorded for at least 20 seconds avoiding pressure artifacts. Microcirculation images were obtained using SDF videomicroscopy (Microscan®, Microvision Medicals, Amsterdam, Netherlands). Data recorded to the hard drive of personal computer using AVA 3.0v software (Microvision Medical, Amsterdam, Netherlands). Video clips were then randomly blinded and later analyzed by 2 independent investigators	After confirmed diagnosis of brain death of any course using cerebral angiography at any time up to 24 hours.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Microvascular flow index (MFI) of sublingual mucosa.	Sublingual mucosa convective oxygen transport presented as MFI of small vessels mostly capillaries with diameter cutoff value of 20µm. Images of microcirculation were taken from at least three different points in sublingual mucosa and recorded for at least 20 seconds avoiding pressure artifacts. Microcirculation images were obtained using SDF videomicroscopy (Microscan®, Microvision Medicals, Amsterdam, Netherlands). Data recorded to the hard drive of personal computer using AVA 3.0v software (Microvision Medical, Amsterdam, Netherlands). Video clips were then randomly blinded and later analyzed by 2 independent investigators.	After confirmed diagnosis of brain death of any course using cerebral angiography at any time up to 24 hours.
Total vessel density (TVD) of sublingual mucosa.	Sublingual mucosa microvascular diffusion distance presented as TVD (mm/mm²) of small vessels mostly capillaries with diameter cutoff value of 20µm. Images of microcirculation were taken from at least three different points in sublingual mucosa and recorded for at least 20 seconds avoiding pressure artifacts. Microcirculation images were obtained using SDF videomicroscopy (Microscan®, Microvision Medicals, Amsterdam, Netherlands). Data recorded to the hard drive of personal computer using AVA 3.0v software (Microvision Medical, Amsterdam, Netherlands). Video clips were then randomly blinded and later analyzed by 2 independent investigators.	After confirmed diagnosis of brain death of any course using cerebral angiography at any time up to 24 hours.
Perfused vessel density (PVD) of sublingual mucosa.	Sublingual mucosa microvascular diffusion distance presented as PVD (mm/mm²) of small vessels mostly capillaries with diameter cutoff value of 20µm. Images of microcirculation were taken from at least three different points in sublingual mucosa and recorded for at least 20 seconds avoiding pressure artifacts. Microcirculation images were obtained using SDF videomicroscopy (Microscan®, Microvision Medicals, Amsterdam, Netherlands). Data recorded to the hard drive of personal computer using AVA 3.0v software (Microvision Medical, Amsterdam, Netherlands). Video clips were then randomly blinded and later analyzed by 2 independent investigators.	After confirmed diagnosis of brain death of any course using cerebral angiography at any time up to 24 hours.

Collaborators and Investigators

• Sponsor: Lithuanian University of Health Sciences
• Investigators: Principal Investigator: Vidas Pilvinis, MD,PhD, Lithuanian UHS Intensive Care Clinic

Publications and helpful links

General Publications

• Ragauskas A, Matijosaitis V, Zakelis R, Petrikonis K, Rastenyte D, Piper I, Daubaris G. Clinical assessment of noninvasive intracranial pressure absolute value measurement method. Neurology. 2012 May 22;78(21):1684-91. doi: 10.1212/WNL.0b013e3182574f50. Epub 2012 May 9.
• Goedhart PT, Khalilzada M, Bezemer R, Merza J, Ince C. Sidestream Dark Field (SDF) imaging: a novel stroboscopic LED ring-based imaging modality for clinical assessment of the microcirculation. Opt Express. 2007 Nov 12;15(23):15101-14. doi: 10.1364/oe.15.015101.
• De Backer D, Hollenberg S, Boerma C, Goedhart P, Buchele G, Ospina-Tascon G, Dobbe I, Ince C. How to evaluate the microcirculation: report of a round table conference. Crit Care. 2007;11(5):R101. doi: 10.1186/cc6118.
• De Backer D, Ospina-Tascon G, Salgado D, Favory R, Creteur J, Vincent JL. Monitoring the microcirculation in the critically ill patient: current methods and future approaches. Intensive Care Med. 2010 Nov;36(11):1813-25. doi: 10.1007/s00134-010-2005-3. Epub 2010 Aug 6.
• Schaser KD, Settmacher U, Puhl G, Zhang L, Mittlmeier T, Stover JF, Vollmar B, Menger MD, Neuhaus P, Haas NP. Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and stenosis-dependent adaptation. J Vasc Surg. 2003 Apr;37(4):789-97. doi: 10.1067/mva.2003.139.
• Miller MM, Chang T, Keating R, Crouch E, Sable C. Blood flow velocities are reduced in the optic nerve of children with elevated intracranial pressure. J Child Neurol. 2009 Jan;24(1):30-5. doi: 10.1177/0883073808321050.
• Pranskunas A, Vellinga NA, Pilvinis V, Koopmans M, Boerma EC. Microcirculatory changes during open label magnesium sulphate infusion in patients with severe sepsis and septic shock. BMC Anesthesiol. 2011 Jun 14;11:12. doi: 10.1186/1471-2253-11-12.
• Tamosuitis T, Pranskunas A, Balciuniene N, Pilvinis V, Boerma EC. Conjunctival microcirculatory blood flow is altered but not abolished in brain dead patients: a prospective observational study. BMC Neurol. 2016 Jul 11;16:95. doi: 10.1186/s12883-016-0618-z.

Study record dates

Study Major Dates

• Study Start: May 1, 2011
• Primary Completion (Actual): September 1, 2015
• Study Completion (Actual): March 1, 2016

Study Registration Dates

• First Submitted: June 18, 2015
• First Submitted That Met QC Criteria: June 23, 2015
• First Posted (Estimate): June 26, 2015

Study Record Updates

• Last Update Posted (Estimate): March 3, 2016
• Last Update Submitted That Met QC Criteria: March 2, 2016
• Last Verified: March 1, 2016

More Information

Terms related to this study

• Keywords: Sublingual microcirculation; Conjunctival microcirculation; Sidestream Dark Field (SDF) microscopy
• Additional Relevant MeSH Terms: Pathologic Processes; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurologic Manifestations; Neurobehavioral Manifestations; Death; Unconsciousness; Consciousness Disorders; Coma; Brain Death
• Other Study ID Numbers: P1-BE-2-19/2011

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED