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Shastri N. Role of Cerebral Oximetry in Extracorporeal Membrane Oxygenation. JOURNAL OF CARDIAC CRITICAL CARE TSS 2022. [DOI: 10.1055/s-0042-1757393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
AbstractCerebral oximetry, which is based on near-infrared spectroscopy (NIRS) technology, is an optical technique that allows for noninvasive and continuous monitoring of brain oxygenation by determining cerebral tissue blood oxygen saturation. Many research and observational studies were performed with neonates using various types of NIRS/cerebral oximetry monitors. However, no food and drug administration (FDA) approved-cerebral oximeter is available for neonates. Successful validation of cerebral oximetry for the FDA has been done in human adult volunteer studies under protocols in which jugular bulb and arterial blood samples were obtained under different levels of fractional inspired oxygen levels.
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Affiliation(s)
- Naman Shastri
- Department of Cardiac Anesthesia, Visiting Faculty for Academics, Training and Research, U.N. Mehta Institute of Cardiology and Research Center, Ahmedabad, Gujarat, India
- Department of Anesthesia, Shri Sathya Sai Institute of Higher Medical Science, Bangalore, Karnataka, India
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Zhang Z, Qi M, Hügli G, Khatami R. Quantitative Changes in Muscular and Capillary Oxygen Desaturation Measured by Optical Sensors during Continuous Positive Airway Pressure Titration for Obstructive Sleep Apnea. BIOSENSORS 2021; 12:bios12010003. [PMID: 35049631 PMCID: PMC8774245 DOI: 10.3390/bios12010003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/24/2021] [Accepted: 12/19/2021] [Indexed: 01/02/2023]
Abstract
Obstructive sleep apnea (OSA) is a common sleep disorder, and continuous positive airway pressure (CPAP) is the most effective treatment. Poor adherence is one of the major challenges in CPAP therapy. The recent boom of wearable optical sensors measuring oxygen saturation makes at-home multiple-night CPAP titrations possible, which may essentially improve the adherence of CPAP therapy by optimizing its pressure in a real-life setting economically. We tested whether the oxygen desaturations (ODs) measured in the arm muscle (arm_OD) by gold-standard frequency-domain multi-distance near-infrared spectroscopy (FDMD-NIRS) change quantitatively with titrated CPAP pressures in OSA patients together with polysomnography. We found that the arm_OD (2.08 ± 1.23%, mean ± standard deviation) was significantly smaller (p-value < 0.0001) than the fingertip OD (finger_OD) (4.46 ± 2.37%) measured by a polysomnography pulse oximeter. Linear mixed-effects models suggested that CPAP pressure was a significant predictor for finger_OD but not for arm_OD. Since FDMD-NIRS measures a mixture of arterial and venous OD, whereas a fingertip pulse oximeter measures arterial OD, our results of no association between arm_OD and finger_OD indicate that the arm_OD mainly represented venous desaturation. Arm_OD measured by optical sensors used for wearables may not be a suitable indicator of the CPAP titration effectiveness.
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Affiliation(s)
- Zhongxing Zhang
- Center for Sleep Medicine, Sleep Research and Epileptology, Clinic Barmelweid AG, 5017 Barmelweid, Switzerland; (M.Q.); (G.H.); (R.K.)
- Barmelweid Academy, Clinic Barmelweid AG, 5017 Barmelweid, Switzerland
- Correspondence:
| | - Ming Qi
- Center for Sleep Medicine, Sleep Research and Epileptology, Clinic Barmelweid AG, 5017 Barmelweid, Switzerland; (M.Q.); (G.H.); (R.K.)
| | - Gordana Hügli
- Center for Sleep Medicine, Sleep Research and Epileptology, Clinic Barmelweid AG, 5017 Barmelweid, Switzerland; (M.Q.); (G.H.); (R.K.)
| | - Ramin Khatami
- Center for Sleep Medicine, Sleep Research and Epileptology, Clinic Barmelweid AG, 5017 Barmelweid, Switzerland; (M.Q.); (G.H.); (R.K.)
- Barmelweid Academy, Clinic Barmelweid AG, 5017 Barmelweid, Switzerland
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, Switzerland
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Zhang Z, Qi M, Hügli G, Khatami R. The Challenges and Pitfalls of Detecting Sleep Hypopnea Using a Wearable Optical Sensor: Comparative Study. J Med Internet Res 2021; 23:e24171. [PMID: 34326039 PMCID: PMC8367170 DOI: 10.2196/24171] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 02/26/2021] [Accepted: 05/24/2021] [Indexed: 12/12/2022] Open
Abstract
Background Obstructive sleep apnea (OSA) is the most prevalent respiratory sleep disorder occurring in 9% to 38% of the general population. About 90% of patients with suspected OSA remain undiagnosed due to the lack of sleep laboratories or specialists and the high cost of gold-standard in-lab polysomnography diagnosis, leading to a decreased quality of life and increased health care burden in cardio- and cerebrovascular diseases. Wearable sleep trackers like smartwatches and armbands are booming, creating a hope for cost-efficient at-home OSA diagnosis and assessment of treatment (eg, continuous positive airway pressure [CPAP] therapy) effectiveness. However, such wearables are currently still not available and cannot be used to detect sleep hypopnea. Sleep hypopnea is defined by ≥30% drop in breathing and an at least 3% drop in peripheral capillary oxygen saturation (Spo2) measured at the fingertip. Whether the conventional measures of oxygen desaturation (OD) at the fingertip and at the arm or wrist are identical is essentially unknown. Objective We aimed to compare event-by-event arm OD (arm_OD) with fingertip OD (finger_OD) in sleep hypopneas during both naïve sleep and CPAP therapy. Methods Thirty patients with OSA underwent an incremental, stepwise CPAP titration protocol during all-night in-lab video-polysomnography monitoring (ie, 1-h baseline sleep without CPAP followed by stepwise increments of 1 cmH2O pressure per hour starting from 5 to 8 cmH2O depending on the individual). Arm_OD of the left biceps muscle and finger_OD of the left index fingertip in sleep hypopneas were simultaneously measured by frequency-domain near-infrared spectroscopy and video-polysomnography photoplethysmography, respectively. Bland-Altman plots were used to illustrate the agreements between arm_OD and finger_OD during baseline sleep and under CPAP. We used t tests to determine whether these measurements significantly differed. Results In total, 534 obstructive apneas and 2185 hypopneas were recorded. Of the 2185 hypopneas, 668 (30.57%) were collected during baseline sleep and 1517 (69.43%), during CPAP sleep. The mean difference between finger_OD and arm_OD was 2.86% (95% CI 2.67%-3.06%, t667=28.28; P<.001; 95% limits of agreement [LoA] –2.27%, 8.00%) during baseline sleep and 1.83% (95% CI 1.72%-1.94%, t1516=31.99; P<.001; 95% LoA –2.54%, 6.19%) during CPAP. Using the standard criterion of 3% saturation drop, arm_OD only recognized 16.32% (109/668) and 14.90% (226/1517) of hypopneas at baseline and during CPAP, respectively. Conclusions arm_OD is 2% to 3% lower than standard finger_OD in sleep hypopnea, probably because the measured arm_OD originates physiologically from arterioles, venules, and capillaries; thus, the venous blood adversely affects its value. Our findings demonstrate that the standard criterion of ≥3% OD drop at the arm or wrist is not suitable to define hypopnea because it could provide large false-negative results in diagnosing OSA and assessing CPAP treatment effectiveness.
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Affiliation(s)
- Zhongxing Zhang
- Center for Sleep Medicine, Sleep Research and Epileptology, Barmelweid, Switzerland.,Barmelweid Academy, Clinic Barmelweid AG, Barmelweid, Switzerland
| | - Ming Qi
- Center for Sleep Medicine, Sleep Research and Epileptology, Barmelweid, Switzerland
| | - Gordana Hügli
- Center for Sleep Medicine, Sleep Research and Epileptology, Barmelweid, Switzerland
| | - Ramin Khatami
- Center for Sleep Medicine, Sleep Research and Epileptology, Barmelweid, Switzerland.,Barmelweid Academy, Clinic Barmelweid AG, Barmelweid, Switzerland.,Department of Neurology, Bern University Hospital and University of Bern, Bern, Switzerland
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Edmonds HL, Ganzel BL, Austin EH. Cerebral Oximetry for Cardiac and Vascular Surgery. Semin Cardiothorac Vasc Anesth 2017; 8:147-66. [PMID: 15248000 DOI: 10.1177/108925320400800208] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The technology of transcranial near-infrared spectroscopy (NIRS) for the measurement of cerebral oxygen balance was introduced 25 years ago. Until very recently, there has been only occasional interest in its use during surgical monitoring. Now, however, substantial technologic advances and numerous clinical studies have, at least partly, succeeded in overcoming long-standing and widespread misunderstanding and skepticism regarding its value. Our goals are to clarify common misconceptions about near-infrared spectroscopy and acquaint the reader with the substantial literature that now supports cerebral oximetric monitoring in cardiac and major vascular surgery.
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Affiliation(s)
- Harvey L Edmonds
- Department of Anesthesiology and Perioperative Medicine, University of Louisville School of Medicine, Louisville, Kentucky 40202-3619, USA.
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Benni PB, MacLeod D, Ikeda K, Lin HM. A validation method for near-infrared spectroscopy based tissue oximeters for cerebral and somatic tissue oxygen saturation measurements. J Clin Monit Comput 2017; 32:269-284. [PMID: 28374103 PMCID: PMC5838152 DOI: 10.1007/s10877-017-0015-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 03/23/2017] [Indexed: 12/19/2022]
Abstract
We describe the validation methodology for the NIRS based FORE-SIGHT ELITE® (CAS Medical Systems, Inc., Branford, CT, USA) tissue oximeter for cerebral and somatic tissue oxygen saturation (StO2) measurements for adult subjects submitted to the United States Food and Drug Administration (FDA) to obtain clearance for clinical use. This validation methodology evolved from a history of NIRS validations in the literature and FDA recommended use of Deming regression and bootstrapping statistical validation methods. For cerebral validation, forehead cerebral StO2 measurements were compared to a weighted 70:30 reference (REF CXB) of co-oximeter internal jugular venous and arterial blood saturation of healthy adult subjects during a controlled hypoxia sequence, with a sensor placed on the forehead. For somatic validation, somatic StO2 measurements were compared to a weighted 70:30 reference (REF CXS) of co-oximetry central venous and arterial saturation values following a similar protocol, with sensors place on the flank, quadriceps muscle, and calf muscle. With informed consent, 25 subjects successfully completed the cerebral validation study. The bias and precision (1 SD) of cerebral StO2 compared to REF CXB was −0.14 ± 3.07%. With informed consent, 24 subjects successfully completed the somatic validation study. The bias and precision of somatic StO2 compared to REF CXS was 0.04 ± 4.22% from the average of flank, quadriceps, and calf StO2 measurements to best represent the global whole body REF CXS. The NIRS validation methods presented potentially provide a reliable means to test NIRS monitors and qualify them for clinical use.
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Affiliation(s)
- Paul B Benni
- CAS Medical Systems (CASMED), Inc., Branford, CT, USA.
| | - David MacLeod
- Human Pharmacology & Physiology Lab, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Keita Ikeda
- Human Pharmacology & Physiology Lab, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA.,Department of Anesthesiology, University of Virginia, Charlottesville, VA, USA
| | - Hung-Mo Lin
- Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Eichhorn L, Kessler F, Böhnert V, Erdfelder F, Reckendorf A, Meyer R, Ellerkmann RK. A Model to Simulate Clinically Relevant Hypoxia in Humans. J Vis Exp 2016. [PMID: 28060323 DOI: 10.3791/54933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In case of apnea, arterial partial pressure of oxygen (pO2) decreases, while partial pressure of carbon dioxide (pCO2) increases. To avoid damage to hypoxia sensitive organs such as the brain, compensatory circulatory mechanisms help to maintain an adequate oxygen supply. This is mainly achieved by increased cerebral blood flow. Intermittent hypoxia is a commonly seen phenomenon in patients with obstructive sleep apnea. Acute airway obstruction can also result in hypoxia and hypercapnia. Until now, no adequate model has been established to simulate these dynamics in humans. Previous investigations focusing on human hypoxia used inhaled hypoxic gas mixtures. However, the resulting hypoxia was combined with hyperventilation and is therefore more representative of high altitude environments than of apnea. Furthermore, the transferability of previously performed animal experiments to humans is limited and the pathophysiological background of apnea induced physiological changes is poorly understood. In this study, healthy human apneic divers were utilized to mimic clinically relevant hypoxia and hypercapnia during apnea. Additionally, pulse-oximetry and Near Infrared Spectroscopy (NIRS) were used to evaluate changes in cerebral and peripheral oxygen saturation before, during, and after apnea.
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Affiliation(s)
- Lars Eichhorn
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Bonn;
| | - Florian Kessler
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Bonn
| | - Volker Böhnert
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn
| | - Felix Erdfelder
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Bonn
| | - Anja Reckendorf
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover
| | | | - Richard K Ellerkmann
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Bonn
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Eichhorn L, Erdfelder F, Kessler F, Doerner J, Thudium MO, Meyer R, Ellerkmann RK. Evaluation of near-infrared spectroscopy under apnea-dependent hypoxia in humans. J Clin Monit Comput 2015; 29:749-57. [PMID: 25649718 DOI: 10.1007/s10877-015-9662-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 01/27/2015] [Indexed: 11/25/2022]
Abstract
In this study we investigated the responsiveness of near-infrared spectroscopy (NIRS) recordings measuring regional cerebral tissue oxygenation (rSO2) during hypoxia in apneic divers. The goal was to mimic dynamic hypoxia as present during cardiopulmonary resuscitation, laryngospasm, airway obstruction, or the "cannot ventilate cannot intubate" situation. Ten experienced apneic divers performed maximal breath hold maneuvers under dry conditions. SpO2 was measured by Masimo™ pulse oximetry on the forefinger of the left hand. NIRS was measured by NONIN Medical's EQUANOX™ on the forehead or above the musculus quadriceps femoris. Following apnea median cerebral rSO2 and SpO2 values decreased significantly from 71 to 54 and from 100 to 65%, respectively. As soon as cerebral rSO2 and SpO2 values decreased monotonically the correlation between normalized cerebral rSO2 and SpO2 values was highly significant (Pearson correlation coefficient = 0.893). Prior to correlation analyses, the values were normalized by dividing them by the individual means of stable pre-apneic measurements. Cerebral rSO2 measured re-saturation after termination of apnea significantly earlier (10 s, SD = 3.6 s) compared to SpO2 monitoring (21 s, SD = 4.4 s) [t(9) = 7.703, p < 0.001, r(2) = 0.868]. Our data demonstrate that NIRS monitoring reliably measures dynamic changes in cerebral tissue oxygen saturation, and identifies successful re-saturation faster than SpO2. Measuring cerebral rSO2 may prove beneficial in case of respiratory emergencies and during pulseless situations where SpO2 monitoring is impossible.
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Affiliation(s)
- Lars Eichhorn
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital Bonn, Bonn, Germany.
| | - Felix Erdfelder
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital Bonn, Bonn, Germany
| | - Florian Kessler
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital Bonn, Bonn, Germany
| | - Jonas Doerner
- Department of Radiology, University Hospital Bonn, Bonn, Germany
| | - Marcus O Thudium
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital Bonn, Bonn, Germany
| | - Rainer Meyer
- Institute of Physiology 2, University of Bonn, Bonn, Germany
| | - Richard K Ellerkmann
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital Bonn, Bonn, Germany
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Varvarousi G, Stefaniotou A, Varvaroussis D, Aroni F, Xanthos T. The role of Levosimendan in cardiopulmonary resuscitation. Eur J Pharmacol 2014; 740:596-602. [PMID: 24972240 DOI: 10.1016/j.ejphar.2014.06.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 06/13/2014] [Accepted: 06/17/2014] [Indexed: 11/30/2022]
Abstract
Although initial resuscitation from cardiac arrest (CA) has increased over the past years, long term survival rates remain dismal. Epinephrine is the vasopressor of choice in the treatment of CA. However, its efficacy has been questioned, as it has no apparent benefits for long-term survival or favorable neurologic outcome. Levosimendan is an inodilator with cardioprotective and neuroprotective effects. Several studies suggest that it is associated with increased rates of return of spontaneous circulation as well as improved post-resuscitation myocardial function and neurological outcome. The purpose of this article is to review the properties of Levosimendan during cardiopulmonary resuscitation (CPR) and also to summarize existing evidence regarding the use of Levosimendan in the treatment of CA.
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Affiliation(s)
- Giolanda Varvarousi
- National and Kapodistrian University of Athens, Medical School, MSc Cardiopulmonary Resuscitation, 75 Mikras Asias Street, 11527 Athens, Greece
| | - Antonia Stefaniotou
- National and Kapodistrian University of Athens, Medical School, MSc Cardiopulmonary Resuscitation, 75 Mikras Asias Street, 11527 Athens, Greece
| | - Dimitrios Varvaroussis
- National and Kapodistrian University of Athens, Medical School, MSc Cardiopulmonary Resuscitation, 75 Mikras Asias Street, 11527 Athens, Greece
| | - Filippia Aroni
- National and Kapodistrian University of Athens, Medical School, MSc Cardiopulmonary Resuscitation, 75 Mikras Asias Street, 11527 Athens, Greece
| | - Theodoros Xanthos
- National and Kapodistrian University of Athens, Medical School, MSc Cardiopulmonary Resuscitation, 75 Mikras Asias Street, 11527 Athens, Greece; Hellenic Society of Cardiopulmonary Resuscitation, Athens, Greece.
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Invasive and noninvasive assessment of cerebral oxygenation in patients with severe traumatic brain injury. Intensive Care Med 2010; 36:1309-17. [PMID: 20502869 DOI: 10.1007/s00134-010-1920-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 03/25/2010] [Indexed: 10/19/2022]
Abstract
PURPOSE The aim of this study is to investigate the relationship between invasive brain tissue oxygen pressure (PbrO(2)) and noninvasive regional transcranial oxygen saturation (rSO(2)) in 22 stable patients with severe traumatic brain injury (TBI) during a 16 h period. METHODS This was a prospective, observational study carried out in the Neurocritical Care Unit of a level 1 trauma center in a teaching hospital. A total of 41,809 paired records for neuromonitoring variables were analyzed and compared. RESULTS A direct and independent correlation between rSO(2) and PbrO(2) was confirmed through adjusted [beta coefficient and (95% confidence interval, CI) = 0.36 (0.35-0.37)] and logistic [PbrO(2) >or=15 mmHg, as a dependent variable; adjusted odds ratio (AOR) and (95% CI) = 1.11 (1.10-1.12)] regression analyses. A receiver-operating characteristic (ROC) curve demonstrated that rSO(2) had low accuracy for detecting moderate (PbrO(2) <or=15 mmHg) intracerebral hypoxia [area under curve (AUC) = 0.62], with the likelihood ratio for a positive test (LR+) = 1.2 for an optimal cutoff of rSO(2) <or=70%. In contrast, the ROC analysis showed that rSO(2) was moderately accurate for detecting severe (PbrO(2) <or=12 mmHg) intracerebral hypoxemia (AUC = 0.82; LR+ = 5.3) for an optimal cutoff of rSO(2) <or=60%. CONCLUSIONS In patients with severe TBI, PbrO(2) and rSO(2) were directly and significantly related. Severe intracerebral hypoxia was better detected by rSO(2) than was moderate intracerebral hypoxia. However, the diagnostic accuracy of rSO(2) was limited, and this measure should not be considered a substitute for routine PbrO(2) monitoring.
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Carlson BW, Neelon VJ, Carlson JR, Hartman M, Dogra S. Cerebrovascular disease and patterns of cerebral oxygenation during sleep in elders. Biol Res Nurs 2009; 10:307-17. [PMID: 19144652 PMCID: PMC3377477 DOI: 10.1177/1099800408330396] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE The aim of this descriptive exploratory study was to describe patterns of cerebral oxygen reserves during sleep and their association with cerebrovascular risk factors in elders. METHOD Participants--115 elders, age 70+ years--were monitored overnight using standard polysomnography. Measures included arterial oxyhemoglobin (SaO2) and regional measures of percentage of cerebral oxyhemoglobin saturation (rcSO2) via cerebral oximetry. Participants were classified based on the magnitude of change in rcSO2 from resting baseline to the end of the first nonrapid-eye-movement (NREM) period. One-way ANOVA and Chi-square were used to test group differences in SaO2 and the prevalence of cerebrovascular risk factors. FINDINGS 20 participants (Group 1) experienced an increase in rcSO2 during sleep along with sleeping rcSO2 levels >or= 55%; 95 participants experienced a decline in rcSO2; 72 participants (Group 2) had sleeping rcSO2 levels >or= 55%; and 23 participants had sleeping rcSO2 levels <55% (Group 3). Although all three groups had equivalent declines in SaO2 levels during sleep, Group 3 had more cardiovascular comorbidity than Groups 1 and 2. CONCLUSIONS Although SaO2 levels decline in most people during sleep, compensatory vascular responses to these drops in SaO2 are important for preventing rcSO2 from falling during sleep. Those entering sleep with lower baseline rcSO2 levels and those with greater declines in cerebral oxygenation during sleep may have greater cardiovascular burden and be at greater risk for stroke and other forms of disabling cerebrovascular disease.
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Affiliation(s)
- Barbara Waag Carlson
- Biobehavioral Laboratory, The University of North Carolina at Chapel Hill, CB# 7460, Carrington Hall, Chapel Hill, NC 27599. PH: (919) 966-7598, FAX: (919) 843-9900,
| | - Virginia J. Neelon
- Biobehavioral Laboratory, The University of North Carolina at Chapel Hill,
| | - John R. Carlson
- School of Nursing, The University of North Carolina at Chapel Hill,
| | - Marilyn Hartman
- Institute on Aging, The University of North Carolina at Chapel Hill,
| | - Sunil Dogra
- Department of Anesthesiology and Pain Management, School of Medicine, The University of North Carolina at Chapel Hill,
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Abstract
INTRODUCTION Vasospasm is a major cause of morbidity after subarachnoid hemorrhage (SAH), and current screening techniques (angiography, transcranial Doppler [TCD], and clinical examination) have serious limitations. Brain oximetry is a promising noninvasive tool to detect reduced brain oxygenation from vasospasm. METHODS Consecutive SAH patients at high risk for vasospasm were monitored with the INVOS (Somanetics, IL, USA) 5100C cerebral oximeter. We prospectively collected oximeter readings (rO2) with concurrent values for vital signs, intracerebral pressure (ICP), arterial blood gas measurement, and hemoglobin (HGB). Data were prospectively collected every 12 h and at clinical events (angiography, transfusion, etc.). We prospectively recorded clinical history, clinical events, radiology results, and outcomes. RESULTS Six patients were measured 123 times. rO2 values were correlated with the contralateral side, HGB, blood pressure, and PaO2, but not with ICP or perfusion pressure. There were no measured effects of angiography or transfusion. Patterns relating rO2 readings to clinical, angiographic, or TCD evidence of vasospasm were unclear, and there were no associations with the outcome (cerebral infarction, NIH Stroke Scale, or modified Rankin Scale). CONCLUSION INVOS rO2 readings are associated with other factors that relate to cerebral oxygen delivery but seem to be of limited use as a screening tool for vasospasm or cerebral infarction after SAH.
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Koudouna E, Xanthos T, Bassiakou E, Goulas S, Lelovas P, Papadimitriou D, Tsirikos N, Papadimitriou L. Levosimendan improves the initial outcome of cardiopulmonary resuscitation in a swine model of cardiac arrest. Acta Anaesthesiol Scand 2007; 51:1123-9. [PMID: 17697310 DOI: 10.1111/j.1399-6576.2007.01383.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Cardiac arrest remains the leading cause of death in Western societies. Advanced Life Support guidelines propose epinephrine (adrenaline) for its treatment. The aim of this study was to assess whether a calcium sensitizer agent, such as levosimendan, administered in combination with epinephrine during cardiopulmonary resuscitation, would improve the initial resuscitation success. METHODS Ventricular fibrillation was induced in 20 Landrace/Large-White piglets, and left untreated for 8 min. Resuscitation was then attempted with precordial compressions, mechanical ventilation and electrical defibrillation. The animals were randomized into two groups (10 animals each): animals in Group A received saline as placebo (10 ml dilution, bolus) + epinephrine (0.02 mg/kg), and animals in Group B received levosimendan (0.012 mg/kg/10 ml dilution, bolus) + epinephrine (0.02 mg/kg) during cardiopulmonary resuscitation. Electrical defibrillation was attempted after 10 min of ventricular fibrillation. RESULTS Four animals in Group A showed restoration of spontaneous circulation and 10 in Group B (P = 0.011). The coronary perfusion pressure, saturation of peripheral oxygenation and brain regional oxygen saturation were significantly higher during cardiopulmonary resuscitation in Group B. CONCLUSIONS A calcium sensitizer agent, when administered during cardiopulmonary resuscitation, significantly improves initial resuscitation success and increases coronary perfusion pressure during cardiopulmonary resuscitation.
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Affiliation(s)
- E Koudouna
- Department of Experimental Surgery and Surgical Research, Medical School, University of Athens, 15B Agiou Thoma Street, 11527 Athens, Greece
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Rais-Bahrami K, Rivera O, Short BL. Validation of a noninvasive neonatal optical cerebral oximeter in veno-venous ECMO patients with a cephalad catheter. J Perinatol 2006; 26:628-35. [PMID: 16900202 DOI: 10.1038/sj.jp.7211573] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
INTRODUCTION Cerebral Oximetry is an optical technique that allows for noninvasive and continuous monitoring of brain oxygenation by determining tissue oxygen saturation (SctO2). In conjunction with pulse oximetry, cerebral oximetry offers a promising method to estimate cerebral venous oxygen saturation (SvO2). OBJECTIVE The aim of this study was to validate the cerebral oximetry measurements with the cerebral oxygen saturation measured from blood drawn in neonates on veno-venous ECMO with existing cephalad catheter with a prototype neonatal cerebral oximeter developed by CAS Medical Systems (Branford, CT, USA). STUDY DESIGN After obtaining informed consent, neonates undergoing VV-ECMO with cephalad catheterization were monitored by the CAS cerebral oximeter. Cephalad blood samples were periodically obtained to validate the monitor's accuracy. RESULTS Seventeen neonates were studied with 1718 h of cerebral oximetry data collected. Compared to the reference values, the bias+/-precision for cerebral oximetry SctO2 was 0.4+/-5.1% and derived SvO2 was 0.6+/-7.3%. CONCLUSION We recommend the use of this noninvasive method as an alternative to blood draws for cerebral venous saturation measurements in neonates requiring extracorporeal life support.
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Affiliation(s)
- K Rais-Bahrami
- Department of Neonatology, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA.
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Peltonen JE, Kowalchuk JM, Paterson DH, DeLorey DS, duManoir GR, Petrella RJ, Shoemaker JK. Cerebral and muscle tissue oxygenation in acute hypoxic ventilatory response test. Respir Physiol Neurobiol 2006; 155:71-81. [PMID: 16697712 DOI: 10.1016/j.resp.2006.03.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 03/10/2006] [Accepted: 03/28/2006] [Indexed: 11/26/2022]
Abstract
Eight men were exposed to progressive isocapnic hypoxia for 10 min to test the hypothesis that (i) cerebral and muscle tissue would follow similar deoxygenation profiles during an acute hypoxic ventilatory response (AHVR) test; and (ii) strong cerebrovascular responsiveness to hypoxia would be related to attenuated cerebral deoxygenation. End-tidal O(2) concentration was reduced from normoxia (approximately 102 mmHg) to approximately 45 mmHg while arterial oxygen saturation (SpO2 %) declined from 98+/-1% to 77+/-7% (P<0.001). Near-infrared spectroscopy (NIRS)-derived local cerebral tissue (frontal lobe) deoxyhemoglobin increased 5.55+/-2.22 microM, while oxyhemoglobin and tissue oxygenation index decreased 2.57+/-1.99 microM and 6.2+/-3.4%, respectively (all P<0.001). In muscle (m. vastus lateralis) the NIRS changes from the initial normoxic level were non-significant. Cerebral blood velocity (V(mean), transcranial Doppler) in the middle cerebral artery increased from 53.4+/-10.4 to 60.6+/-11.6 cms(-1) (P<0.001). In relation to the decline in SpO2 % the mean rate of increase of V(mean) and AHVR were 0.33+/-0.19 cms(-1)%(-1) and 0.52+/-0.20l min(-1)%(-1), respectively. We conclude that cerebral, but not muscle, tissue shows changes reflecting a greater deoxygenation during acute hypoxia. However, the changes in NIRS parameters were not related to cerebrovascular responsiveness or ventilatory chemosensitivity during graded hypoxia.
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Affiliation(s)
- Juha E Peltonen
- Unit for Sports and Exercise Medicine, Institute of Clinical Medicine, University of Helsinki, Helsinki, Finland.
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Hung YC, Huang CJ, Kuok CH, Chen CC, Hsu YW. The effect of hemodynamic changes induced by propofol induction on cerebral oxygenation in young and elderly patients. J Clin Anesth 2005; 17:353-7. [PMID: 16102685 DOI: 10.1016/j.jclinane.2004.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2003] [Accepted: 09/09/2004] [Indexed: 10/25/2022]
Abstract
STUDY OBJECTIVE To investigate the difference of regional cerebral oxygen saturation (rSo2) decrease in response to the decrease in mean arterial blood pressure (MAP) in young and elderly patients. DESIGN Prospective clinical study. SETTING Medical center hospital. PATIENTS Twenty-four American Society of Anesthesiologists physical status I and II patients, 12 of whom were young and the other 12 elderly, scheduled for elective surgery requiring general anesthesia. Patients received propofol 2 mg/kg (young patient group) and propofol 1.5 mg/kg (elderly patient group) as an induction drug. MEASUREMENTS MAP and rSo2 were recorded continuously for 5 minutes after propofol administration. MAIN RESULTS MAP values at the second to fifth minutes and rSo2 at the second minute after propofol administration were significantly lower than baseline in both groups (P<.05). The rSo2 decrease was minimal, and the slopes of the rSo2 decrease in response to the MAP decrease in the young and elderly groups were 0.093+/-0.012 (P<.001) and 0.112+/-0.016 (P<.001) (mean+/-SEM), respectively. CONCLUSIONS After propofol induction, there was no difference between young and elderly patients in rSo2 decrease in response to the decrease in MAP.
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Affiliation(s)
- Yu-Chun Hung
- Department of Anesthesiology, Mackay Memorial Hospital, and Mackay Medicine, Nursing and Management College, Taipei, Taiwan, 10449
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Kolb JC, Ainslie PN, Ide K, Poulin MJ. Protocol to measure acute cerebrovascular and ventilatory responses to isocapnic hypoxia in humans. Respir Physiol Neurobiol 2004; 141:191-9. [PMID: 15239969 DOI: 10.1016/j.resp.2004.04.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2004] [Indexed: 10/26/2022]
Abstract
This study describes a protocol to determine acute cerebrovascular and ventilatory (AHVR) responses to hypoxia. Thirteen subjects undertook a protocol twice, 5 days apart. The protocol started with 8 min of eucapnic euoxia (end-tidal P(CO2) (PET(CO2)= 1.5 Torr) above rest; end-tidal P(O2) (PET(O2)) = 88 Torr) followed by six descending 90 s hypoxic steps (PET(O2) = 75.2, 64.0, 57.0, 52.0, 48.2, 45.0 Torr). Then, PET(O2) was elevated to 300 Torr for 10 min while PET(O2) remained at eucapnia (5 min) then raised by 7.5 Torr (5 min). Peak blood flow velocity in the middle cerebral artery (MCA) and regional cerebral oxygen saturation (Sr(O2)) were measured with transcranial Doppler ultrasound and near-infrared spectroscopy, respectively, and indices of acute hypoxic sensitivity were calculated (AHR(CBF) and AHRSr(O2)). Values for AHR(CBF), AHRSr(O2) and AHVR were 0.43 cm s(-1) % desaturation(-1), 0.80% % desaturation(-1) and 1.24l min(-1) % desaturation(-1), respectively. Coefficients of variation for AHR(CBF), AHRSr(O2) and AHVR were small (range = 8.0-15.2%). This protocol appears suitable to quantify cerebrovascular and ventilatory responses to acute isocapnic hypoxia.
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Affiliation(s)
- Jon C Kolb
- Faculty of Kinesiology, University of Calgary, Calgary, Alta., T2N 4N1, Canada
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Kolb JC, Ainslie PN, Ide K, Poulin MJ. Effects of five consecutive nocturnal hypoxic exposures on the cerebrovascular responses to acute hypoxia and hypercapnia in humans. J Appl Physiol (1985) 2004; 96:1745-54. [PMID: 14729726 DOI: 10.1152/japplphysiol.00977.2003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The effects of discontinuous hypoxia on cerebrovascular regulation in humans are unknown. We hypothesized that five nocturnal hypoxic exposures (8 h/day) at a simulated altitude of 4,300 m (inspired O2 fraction = ∼13.8%) would elicit cerebrovascular responses that are similar to those that have been reported during chronic altitude exposures. Twelve male subjects (26.6 ± 4.1 yr, mean ± SD) volunteered for this study. The technique of end-tidal forcing was used to examine cerebral blood flow (CBF) and regional cerebral O2 saturation (SrO2) responses to acute variations in O2 and CO2 twice before, immediately after, and 5 days after the overnight hypoxic exposures. Transcranial Doppler ultrasound was used to assess CBF, and near-infrared spectroscopy was used to assess SrO2. Throughout the nocturnal hypoxic exposures, end-tidal Pco2 decreased ( P < 0.001) whereas arterial O2 saturation increased ( P < 0.001) compared with overnight normoxic control measurements. Symptoms associated with altitude illness were significantly greater than control values on the first night ( P < 0.001) and second night ( P < 0.01) of nocturnal hypoxia. Immediately after the nocturnal hypoxic intervention, the sensitivity of CBF to acute variations in O2 and CO2 increased 116% ( P < 0.01) and 33% ( P < 0.05), respectively, compared with control values. SrO2 was highly correlated with arterial O2 saturation ( R2 = 0.94 ± 0.04). These results show that discontinuous hypoxia elicits increases in the sensitivity of CBF to acute variations in O2 and CO2, which are similar to those observed during chronic hypoxia.
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Affiliation(s)
- Jon C Kolb
- Faculty of Kinesiology, Department of Physiology & Biophysics, University of Calgary, Calgary, Alberta, Canada T2N 4N1
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Akça O, Sessler DI. Use of cerebral oximetry to detect and manage cerebral desaturation with a rapidly expanding neck hematoma. Acta Anaesthesiol Scand 2002; 46:607-8. [PMID: 12027858 DOI: 10.1034/j.1399-6576.2002.460521.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND We report a case in which cerebral oximetry was used to successfully demonstrate when cerebral oxygen saturation is dangerously low. METHODS In a 60-year-old-man with end-stage multiple myeloma and hyperviscosity syndrome, a rapidly expanding hematoma developed after insertion of an internal jugular central venous catheter. As the hematoma expanded, the patient became lethargic and disoriented (Glasgow Coma Score of E2/M4-5/V2-ETT). His platelet count was 17,000.mm(-3), hemoglobin was 4.5 g/dl, partial thromboplastin time was 51 s, and his international ratio was 1.7. Although carotid pulses became unpalpable, blood pressure and heart rate remained stable. Cerebral oximeter probes positioned on the patient's forehead showed that cerebral oxygen saturation was 22-26% bilaterally. The surgery team was advised to surgically evacuate the hematoma. RESULTS The hematoma was evacuated and a small needle hole in the right internal jugular vein adjacent to the central-venous catheter was found and repaired. Cerebral oxygen saturation increased to 56-58% within 1 h and stabilized near 60%. The patient awoke with normal cognitive function. CONCLUSION This case demonstrates how cerebral oximetry can be used to give quantitative evidence of cerebral hypoxia, thus showing that immediate surgical intervention is necessary.
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Affiliation(s)
- O Akça
- Outcomes Research Institute and Department of Anesthesiology, University of Louisville, KY 40202, USA.
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