Noninvasive Conjunctival Oxygen Monitoring During Carotid Endarterectomy

Kram, Harry B.; Shoemaker, William C.; Bratanow, N.; Appel, Paul L.; Sterling, Rosalyn P.; Fleming, Arthur W.

doi:10.1097/00132586-198706000-00017

Cited by 3 publications

(5 citation statements)

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“…This is substantiated under both pre-ischemic and ischemic conditions, as the sequence of clamping and unclamping of the ICA during surgery was continuously analyzed. Our findings are in accord with those of Kram et al, 13 who reported that ICA clamping for endarterectomy significantly reduces conjunctival oxygen tension, which is completely restored with ICA reperfusion. 13 The immediate responsiveness of the conjunctival microcirculation to ICA clamping and reperfusion enables valid analysis and direct evaluation of the efficiency of shunt perfusion.…”

Section: Discussionsupporting

confidence: 93%

“…Our findings are in accord with those of Kram et al, 13 who reported that ICA clamping for endarterectomy significantly reduces conjunctival oxygen tension, which is completely restored with ICA reperfusion. 13 The immediate responsiveness of the conjunctival microcirculation to ICA clamping and reperfusion enables valid analysis and direct evaluation of the efficiency of shunt perfusion. Therefore, given the possibility of on-line and real-time analysis, OPS imaging may be a complementary diagnostic tool for detection of reduced ICA blood flow during ICA shunting and possibly unmasking a defective shunt.…”

Section: Discussionsupporting

confidence: 93%

“…Previous studies in which the conjunctiva was used for intraoperative monitoring by measuring oxygen tension during carotid artery surgery did not directly visualize the microcirculation and yielded conflicting results. [13][14][15] Recently a new technology, ie, orthogonal polarized spectral (OPS) imaging, has been introduced, enabling noninvasive investigation and quantification of the human microcirculation in vivo 16 by placing a special camera at a distance of 0.5-1 mm to the surface of the target organ. Cross-polarization of the reflected green light results in hemoglobindependent contrast enhancement of vascular structures.…”

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confidence: 99%

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Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and stenosis-dependent adaptation

Schaser¹,

Settmacher²,

Puhl³

et al. 2003

Journal of Vascular Surgery

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These results suggest adaptive mechanisms of capillary perfusion with increasing stenosis and development of collateral compensatory circulation in the vascular region of the human ICA. Conjunctival orthogonal polarized spectral imaging during unilateral ICA reconstruction enables continuous noninvasive analysis of bilateral conjunctival microcirculation in the terminal region of the ICA and enables monitoring for efficient carotid shunt perfusion during and after endarterectomy.

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Section: Discussionsupporting

confidence: 93%

Section: Discussionsupporting

confidence: 93%

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confidence: 99%

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Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and stenosis-dependent adaptation

Schaser¹,

Settmacher²,

Puhl³

et al. 2003

Journal of Vascular Surgery

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“…Reasonable estimates for the standard deviation of the diffusion enlarged PSF in the nasal fundus (near the optic nerve head) are -60 pm from 450 to 575 nm and -180 Rm from 600 to 750 nm. 28 A fraction of this diffused light Idp will pass back through the vessel to be absorbed and scattered in double pass, while another fraction IP will extend beyond the edge of the vessel and exit the pupil in single pass.…”

Section: Multipass Transmission In Oximetrymentioning

confidence: 99%

An Eye Oximeter for Combat Casualty Care

Denninghoff¹

1999

PsycEXTRA Dataset

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Public .eporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing Instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of Information, Including suggestions for reducing this burden to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503. AGENCY USE ONLY (Leave blank) 2, REPORT DATE REPORT TYPE AND DATES COVERED I January 1999Annual 4. TITLE AND SUBTITLE FUNDING NUMBERSAn Eye Oximeter for Combat Casualty Care DAMD179818007 AUTHOR(S)Denninghoff, Kurt, M.D. PERFORMING ORGANIZATION NAMES(S) AND ADDRESS(ES)8 ABSTRACT (Maximum 200 words)Blood pressure and pulse are particularly inaccurate when used to identify early blood loss in trauma victims. This research supports the continued development of a system for noninvasively monitoring blood loss. We have developed a breadboard Eye Oximeter (EOX) which shines low power lasers into a subject's eye and scans the beams across the arteries and veins of the retina. The back reflected light is collected and from these signals, we calculate the oxygen saturation of the blood within the retinal vessels. Prior to initiating this contract, we completed swine studies that demonstrated a strong correlation between retinal venous oxygen saturation and early blood loss. During the past year, we have completed construction of a prototype Eye Oximeter, performed model eye experiments with this prototype which verify in vitro calibration, performed pilot human experiments which demonstrate significant improvements in our prototype, and begun animal testing of the device. We have also completed the development and design of a video oximeter (EOX-2) as anticipated in our statement of work. We have completed the construction of the EOX-2 breadboard and testing of the device has begun. In this Annual Report we document the studies, results and analysis which we performed under contract. (NIH Publication No. 86-23, Revised 1985).For the protection of human subjects, the investigator (s) have adhered to policies of applicable Federal Law 45 CFR 46.In conducting research utilizing recombinant DNA, the investigator(s) adhered to NIH Guidelines for Research Involving Recombinant DNA Molecules.In the conduct of research involving hazardous organisms, the investigator(s) adhered to the CDC-NIH Guide for Biosafety in Microbiological and Biomedical Laboratories. IntroductionExsanguination is the most immediate life threatening danger for the field casualty during wartime. Indeed, 60% of all deaths from battlefield abdominal injuries are due to hemorrhage. If these casualties of war survive, they often require massive transfusions and sophis...

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“…Continuous monitoring of Pcjo, has been suggested to be useful also for assessment of the cerebral circu-lation during carotid artery surgery (10,11). A decrease in Pcjo, is thus demonstrable during the clamping of the carotid vessels, but the change in Pcjo, has not been related to the efficiency of the collateral circulation, i.e.…”

mentioning

confidence: 99%

Continuous conjunctival oxygen tension (Pcjo₂) monitoring for assessment of cerebral oxygenation and metabolism during carotid artery surgery

Haljamäe

Frid

Holm

et al. 1989

Acta Anaesthesiol Scand

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The clinical value of noninvasive continuous monitoring of conjunctival oxygen tension for assessment of cerebral perfusion during carotid endarterectomy performed under general anaesthesia has been evaluated. The patients (n = 17; mean age 62.5 +/- 1.7 years) were monitored as follows: conjunctival oxygen tension (PcjO2); internal jugular venous oxygen tension at the skull base level (PcijvO2); arterial blood pressure; arterial and internal jugular venous blood gases; acid-base data and lactate, pyruvate levels; end-tidal CO2 concentration. The mean preanaesthetic PcjO2 level of 4.86 +/- 0.40 kPa was significantly lower than PaO2(PcjO2)/PaO2 ratio of 0.48). Following anaesthesia, a larger PcjO2-PaO2 gradient (ratio 0.32) was seen in spite of the hyperoxic situation (FiO2 = 0.40) due to vasoconstriction induced by slight hypocapnia (reduction of PaCO2 from 5.13 +/- 0.08 to 4.64 +/- 0.10 kPa). The carotid artery crossclamping resulted in a rapid and pronounced decrease of PcjO2, while PcijvO2 remained unchanged. No relationship between PcjO2 and stump pressure was found, while a significant correlation (P less than 0.02) between PcjO2 and lactate in effluent venous blood from the brain was demonstrable. It is concluded that PcjO2 monitoring seems a clinically useful trend indicator of cerebral perfusion in the individual patient. Due to large interindividual variations in basal PcjO2 readings and in PcjO2 changes during carotid artery clamping, however, transconjunctival oxygen tension monitoring does not seem to allow early and accurate recognition of impending cerebral ischaemia during carotid endarterectomy, and its routine use therefore seems of limited value.

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Noninvasive Conjunctival Oxygen Monitoring During Carotid Endarterectomy

Cited by 3 publications

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Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and stenosis-dependent adaptation

Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and stenosis-dependent adaptation

An Eye Oximeter for Combat Casualty Care

Continuous conjunctival oxygen tension (Pcjo₂) monitoring for assessment of cerebral oxygenation and metabolism during carotid artery surgery

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Noninvasive Conjunctival Oxygen Monitoring During Carotid Endarterectomy

Cited by 3 publications

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Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and stenosis-dependent adaptation

Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and stenosis-dependent adaptation

An Eye Oximeter for Combat Casualty Care

Continuous conjunctival oxygen tension (Pcjo2) monitoring for assessment of cerebral oxygenation and metabolism during carotid artery surgery

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Continuous conjunctival oxygen tension (Pcjo₂) monitoring for assessment of cerebral oxygenation and metabolism during carotid artery surgery