DOCSLIB.ORG

Effects of Hyperoxia on the Oxygen Distribution in the Intact Cat Retina

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Effects of Hyperoxia on the Oxygen Distribution in the Intact Cat Retina Investigative Ophthalmology & Visual Science, Vol. 30, No. 4, April 1989 Copyright © Association for Research in Vision and Ophthalmology Effects of Hyperoxia on the Oxygen Distribution in the Intact Cat Retina Robert A. Linsenmeier*f and Charles M. Yanceyf Double-barreled oxygen microelectrodes were used to measure the distribution of oxygen within the dark adapted cat retina during systemic hyperoxia (100% O2 inspired). Oxygen tension (PO2) de- creased monotonically from the choroid to the vitreous humor in most cases, showing that a greater portion of the retina was supplied by the choroid during hyperoxia than during normoxia. In the proximal half of the retina the PO2 increased during hyperoxia by an average of about 40 mm Hg, while the increase in the distal retina was larger. At the choroid the average increase in PO2 was about ISO mm Hg. Analysis of the oxygen profiles showed that photoreceptor oxygen consumption was unchanged during hyperoxia. Retinal PO2 increased rapidly at the beginning of hyperoxia, and often partially recovered from its peak value during hyperoxia, even in the distal retina, suggesting that the choroidal circulation may have some limited autoregulatory capacity. As in normoxia, retinal illumina- tion led to an increase in PO2 in the distal retina, due to a decrease in oxygen consumption. The light-evoked increase in PO2 was larger during hyperoxia, but the underlying change in oxygen consumption was probably the same as in normoxia. Invest Ophthalmol Vis Sci 30:612-618,1989 Numerous studies have shown that adequate has been controversial. Some investigators suggest amounts of oxygen are essential for normal retinal that diffusion of oxygen from the choroid is essential function, and in higher mammals both the choroidal in causing vasoconstriction of retinal vessels in hy- and retinal circulations are necessary (eg, refs. 1-3). peroxia4 but the m'ost recent data15 suggest that oxy- When the retinal circulation is compromised, it is gen carried by the retinal circulation must be impor- believed that the choroidal circulation may be able to tant. Less is known' about the PO2 in the distal retina supply most or all of the retina, provided that the during hyperoxia, since this cannot be measured with 4 5 arterial oxygen tension (PaO2) is elevated, ' but hy- vitreal electrodes. Choroidal blood flow is generally peroxia can have deleterious effects as well. If in- considered to be passive with respect to changes in 6 1617 spired PO2 is very high, retinal oxidative metabolism PaO2, and since oxygen extraction from the cho- + + 7 218 and Na -K ATPase activity are reduced. The retina roid is small choroidal PO2 would be expected to is also more susceptible to light damage in hyperoxic rise substantially when PaO2 is elevated. This has, in monkeys than in normoxic ones.8 Finally, the best fact, been demonstrated in the pig retina.19 example of the detrimental effect of hyperoxia is that The current work was undertaken to provide data it prevents normal retinal vascular development in on the oxygen distribution across the retina during premature infants (eg, ref. 9). hyperoxia, since this basic information is important Measurements of vitreal PO2 have shown that in several of the contexts mentioned above. The ef- inner retinal PO2 is reasonably well regulated during fect of light on the oxygen distribution has been eval- hyperoxia,10 due to the constriction of retinal ves- uated, since this has even more dramatic effects dur- sels""13 and the consequent reduction of retinal ing hyperoxia than during normoxia.3 Modelling of blood flow.12"14 The mechanism of the constriction oxygen transport has been employed to address issues related to retinal oxygen consumption. From the *Departments of Biomedical Engineering and Neuro- biology and Physiology and the tlnterdepartmental Graduate Pro- Materials and Methods gram in Neuroscience, Northwestern University, Evanston, Illi- nois. The methods for animal preparation, recording Supported by NIH grant EY-05034, Bethesda, Maryland, and and visual stimulation were the same as those pre- the Whitaker Foundation. viously published.320 Fourteen adult cats were used Submitted for publication: February 18, 1988; accepted October in this study. We have adhered to the ARVO Resolu- 26, 1988. tion on the Use of Animals in Research. During nor- Reprint requests: Dr. Robert A. Linsenmeier, Biomedical Engi- neering Department, Northwestern University, 2145 Sheridan moxia the animals breathed air, supplemented when Road, Evanston, IL 60208. necessary with enough O2 to keep arterial PO2 above 612 Downloaded from iovs.arvojournals.org on 09/26/2021 613 No. 4 HYPEROXIC EFFECTS ON RETINAL PO2 / Linsenmeier and Yoncey 85 mm Hg. Hyperoxia was induced with 100% in- Normoxia spired O2. During normoxia.the average PaO2 was 98.6 ± 13.0 mm Hg (mean ± SD; n = 27) and during hyperoxia it was 415.5 ± 72.3 mm Hg (n = 54). Arte- rial pH and PCO2 were 7.42 ± 0.04 and 31.3 ± 5.6 mm Hg during normoxia, and were unchanged (by paired t-test) during hyperoxia. Arterial blood pres- sure was generally unchanged by hyperoxia. The du- ration of hyperoxia varied from 6 min to about 2 hr depending on the type of experiment being per- formed. Results Oxygen Profiles in the Dark-Adapted Retina The distribution of oxygen in the dark-adapted ret- ina was measured during electrode penetrations and 0 L withdrawals. During penetrations the electrode was 100 80 60 40 20 0 advanced in 3 /im steps from the vitreal surface to the choroid, and at approximately 20 uta intervals the Retinal depth (%) current was allowed to stabilize and was recorded. Fig. 1. Profiles of retinal oxygen tension during electrode with- Withdrawals were performed with the electrode drawal from choroid (100% depth) to vitreous (0% depth) during moving in 1 fim steps at 1 or 1.5 /xm per sec. The (A) normoxia, and (B) and (C) hyperoxia. Each profile is a single retinal depth of the electrode was assessed with the withdrawal during dark adaptation; 100% depth was the point at local electroretinogram, which was recorded with the which the reference barrel recorded the increase in potential across the retinal pigment epithelium, which coincided with the beginning reference barrel.3 Recordings were usually made in or of the PO2 decrease. Zero was taken to be the point at which the near the area centralis. Figure 1 shows oxygen profiles ERG b-wave changed from a negative intraretinal polarity to a (ie, PO2 as a function of retinal depth) measured dur- positive vitreal polarity. B was recorded in the area centralis (cat ing electrode withdrawals during air breathing (nor- 31). C was recorded during hyperoxia near the superior retinal moxia) (Fig. 1 A) and hyperoxia (Fig. IB) in the same artery and shows a peak in PO2 in the proximal retina (cat 31). animal. The typical normoxic profile320 showed a rel- atively high PO at the choroid and then a steep gra- 2 profile in most of the retina is more likely to be simi- dient, culminating in a PO of close to zero mm Hg 2 lar to that in Figure IB. between 65 and 85% retinal depth. The PO then rose 2 A substantial variation was observed in choroidal in the inner half of the retina, where the PO2 averaged PO2 during both normoxia and hyperoxia, as shown about 20 mm Hg. During hyperoxia the PO2 in- creased throughout the retina, but the most dramatic in Figure 2. During normoxia the average choroidal change was in the outer retina, where the minimum PO2 was 77.2 ± 20.7 mm Hg (n = 24), while during was eliminated. Since profiles were never measured hyperoxia it was 230 ± 87 mm Hg (n = 18). The in exactly the same location twice, this type of mea- corresponding arterial PO2s were 98.6 ± 11-0 and 436 surement was not suitable for determining the size of ±57 mm Hg. Thus, in both absolute and relative terms, the difference between arterial and choroidal changes in PO2 at any depth. They did show, how- ever, that in most cases (seven of eight penetrations PO2 was greater during hyperoxia. and 15 of 20 withdrawals in eight cats), PO2 increased monotonically, but not linearly, from the vitreal sur- Oxygen Consumption during Hyperoxia face to the choroid. The slope of the profile in the As described in the previous paper,20 oxygen pro- distal half of the retina was usually at least twice as files can be subjected to a steady-state diffusion analy- great as the slope in the proximal half of the retina. sis that allows estimation of the parameter Q/Dk, Several profiles showed the same features as de- which includes consumption per unit volume of tis- scribed above in the distal retina, but also had a rela- sue per time (Q), oxygen solubility (k) and oxygen tive maximum in PO2 in the proximal retina. The diffusion coefficient (D). As in the previous paper, the largest effect of this type was observed close to the avascular layer was divided into three sublayers superior retinal artery (Fig. 1C). Since this type of whose thicknesses were determined by fitting data to profile was observed only very near large vessels, the the model. The layer closest to the choroid (0 < x Downloaded from iovs.arvojournals.org on 09/26/2021 614 INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE / April 1989 Vol. 30 400 6 200 0 L ' 0 100 200 300 400 500 600 Arterial PO2 (mm Hg) Fig. 2. Choroidal PO2 as a function of arterial PO2 during nor- 30 mm Hg moxia (left group of points) and hyperoxia (right group of points). 100% oxygen The solid line connects the means of arterial and choroidal PO2 5 min under the two conditions.
Load more

Recommended publications
  • Respiratory and Gastrointestinal Involvement in Birth Asphyxia
    Academic Journal of Pediatrics & Neonatology ISSN 2474-7521 Research Article Acad J Ped Neonatol Volume 6 Issue 4 - May 2018 Copyright © All rights are reserved by Dr Rohit Vohra DOI: 10.19080/AJPN.2018.06.555751 Respiratory and Gastrointestinal Involvement in Birth Asphyxia Rohit Vohra1*, Vivek Singh2, Minakshi Bansal3 and Divyank Pathak4 1Senior resident, Sir Ganga Ram Hospital, India 2Junior Resident, Pravara Institute of Medical Sciences, India 3Fellow pediatrichematology, Sir Ganga Ram Hospital, India 4Resident, Pravara Institute of Medical Sciences, India Submission: December 01, 2017; Published: May 14, 2018 *Corresponding author: Dr Rohit Vohra, Senior resident, Sir Ganga Ram Hospital, 22/2A Tilaknagar, New Delhi-110018, India, Tel: 9717995787; Email: Abstract Background: The healthy fetus or newborn is equipped with a range of adaptive, strategies to reduce overall oxygen consumption and protect vital organs such as the heart and brain during asphyxia. Acute injury occurs when the severity of asphyxia exceeds the capacity of the system to maintain cellular metabolism within vulnerable regions. Impairment in oxygen delivery damage all organ system including pulmonary and gastrointestinal tract. The pulmonary effects of asphyxia include increased pulmonary vascular resistance, pulmonary hemorrhage, pulmonary edema secondary to cardiac failure, and possibly failure of surfactant production with secondary hyaline membrane disease (acute respiratory distress syndrome).Gastrointestinal damage might include injury to the bowel wall, which can be mucosal or full thickness and even involve perforation Material and methods: This is a prospective observational hospital based study carried out on 152 asphyxiated neonates admitted in NICU of Rural Medical College of Pravara Institute of Medical Sciences, Loni, Ahmednagar, Maharashtra from September 2013 to August 2015.
    [Show full text]
  • Acute Effects of Mechanical Ventilation with Hyperoxia on the Morphometry of the Rat Diaphragm
    ISSN 1413-3555 Rev Bras Fisioter, São Carlos, v. 13, n. 6, p. 487-92, nov./dez. 2009 ARTIGO ORIGIN A L ©Revista Brasileira de Fisioterapia Efeitos agudos da ventilação mecânica com hiperoxia na morfometria do diafragma de ratos Acute effects of mechanical ventilation with hyperoxia on the morphometry of the rat diaphragm Célia R. Lopes1, André L. M. Sales2, Manuel De J. Simões3, Marco A. Angelis4, Nuno M. L. Oliveira5 Resumo Contextualização: A asssistência ventilória mecânica (AVM) prolongada associada a altas frações de oxigênio produz impacto negativo na função diafragmática. No entanto, não são claros os efeitos agudos da AVM associada a altas frações de oxigênio em pulmões aparentemente sadios. Objetivo: Analisar os efeitos agudos da ventilação mecânica com hiperóxia na morfometria do diafragma de ratos. Métodos: Estudo experimental prospectivo, com nove ratos Wistar, com peso de 400±20 g, randomizados em dois grupos: controle (n=4), anestesiados, traqueostomizados e mantidos em respiração espontânea em ar ambiente por 90 minutos e experimental (n=5), também anestesiados, curarizados, traqueostomizados e mantidos em ventilação mecânica controlada pelo mesmo tempo. Foram submetidos à toracotomia mediana para coleta da amostra das fibras costais do diafragma que foram seccionadas a cada 5 µm e coradas pela hematoxilina e eosina para o estudo morfométrico. Para a análise estatística, foi utilizado o teste t de Student não pareado, com nível de significância de p<0,05. Resultados: Não foram encontrados sinais indicativos de lesão muscular aguda, porém observou-se dilatação dos capilares sanguíneos no grupo experimental. Os dados morfométricos do diâmetro transverso máximo da fibra muscular costal foram em média de 61,78±17,79 µm e de 70,75±9,93 µm (p=0,045) nos grupos controle e experimental respectivamente.
    [Show full text]
  • Subacute Normobaric Oxygen and Hyperbaric Oxygen Therapy in Drowning, Reversal of Brain Volume Loss: a Case Report
    [Downloaded free from http://www.medgasres.com on Monday, July 3, 2017, IP: 12.22.86.35] CASE REPORT Subacute normobaric oxygen and hyperbaric oxygen therapy in drowning, reversal of brain volume loss: a case report Paul G. Harch1, *, Edward F. Fogarty2 1 Department of Medicine, Section of Emergency Medicine, University Medical Center, Louisiana State University School of Medicine, New Orleans, LA, USA 2 Department of Radiology, University of North Dakota School of Medicine, Bismarck, ND, USA *Correspondence to: Paul G. Harch, M.D., [email protected] or [email protected]. orcid: 0000-0001-7329-0078 (Paul G. Harch) Abstract A 2-year-old girl experienced cardiac arrest after cold water drowning. Magnetic resonance imaging (MRI) showed deep gray mat- ter injury on day 4 and cerebral atrophy with gray and white matter loss on day 32. Patient had no speech, gait, or responsiveness to commands on day 48 at hospital discharge. She received normobaric 100% oxygen treatment (2 L/minute for 45 minutes by nasal cannula, twice/day) since day 56 and then hyperbaric oxygen treatment (HBOT) at 1.3 atmosphere absolute (131.7 kPa) air/45 minutes, 5 days/week for 40 sessions since day 79; visually apparent and/or physical examination-documented neurological improvement oc- curred upon initiating each therapy. After HBOT, the patient had normal speech and cognition, assisted gait, residual fine motor and temperament deficits. MRI at 5 months after injury and 27 days after HBOT showed near-normalization of ventricles and reversal of atrophy. Subacute normobaric oxygen and HBOT were able to restore drowning-induced cortical gray matter and white matter loss, as documented by sequential MRI, and simultaneous neurological function, as documented by video and physical examinations.
    [Show full text]
  • Short-Time Intermittent Preexposure of Living Human Donors To
    Hindawi Publishing Corporation Journal of Transplantation Volume 2011, Article ID 204843, 8 pages doi:10.1155/2011/204843 Clinical Study Short-Time Intermittent Preexposure of Living Human Donors to Hyperoxia Improves Renal Function in Early Posttransplant Period: A Double-Blind Randomized Clinical Trial Kamran Montazeri,1 Mohammadali Vakily,1 Azim Honarmand,1 Parviz Kashefi,1 Mohammadreza Safavi,1 Shahram Taheri,2 and Bahram Rasoulian3 1 Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, P.O. Box 8174675731, Isfahan 81744, Iran 2 Isfahan Kidney Diseases Research Center (IKRC) and Internal Medicine Department, Alzahra Hospital, Isfahan University of Medical Sciences, P.O. Box 8174675731, Isfahan 81744, Iran 3 Research Center and Department of Physiology, Lorestan University of Medical Sciences, P.O. Box 6814617767, Khorramabad, Iran Correspondence should be addressed to Azim Honarmand, [email protected] Received 6 November 2010; Revised 5 January 2011; Accepted 26 January 2011 Academic Editor: Wojciech A. Rowinski´ Copyright © 2011 Kamran Montazeri et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The purpose of this human study was to investigate the effect of oxygen pretreatment in living kidney donors on early renal function of transplanted kidney. Sixty living kidney donor individuals were assigned to receive either 8–10 L/min oxygen (Group I) by a non-rebreather mask with reservoir bag intermittently for one hour at four times (20, 16, 12, and 1 hours before transplantation) or air (Group II).
    [Show full text]
  • Oxygen Content in Semi-Closed Rebreathing Apparatuses for Underwater Use. Measurements and Modeling
    Doctoral Thesis in Technology and Health Stockholm, Sweden 2015 Oxygen content in semi-closed rebreathing apparatuses for underwater use. Measurements and modeling OSKAR FRÅNBERG KTH ROYAL INSTITUTE OF TECHNOLOGY ENGINEERING SCIENCES Oxygen content in semi-closed rebreathing apparatuses for underwater use. Measurements and modeling OSKAR FRÅNBERG Doctoral thesis No. 6 2015 KTH Royal Institute of Technology Engineering Sciences Department of Environmental Physiology SE-171 65, Solna, Sweden ii TRITA-STH Report 2015:6 ISSN 1653-3836 ISRN/KTH/STH/2015:6-SE ISBN 978-91-7595-616-9 Akademisk avhandling som med tillstånd av KTH i Stockholm framlägges till offentlig granskning för avläggande av teknisk doktorsexamen fredagen den 25/9 2015 kl. 09:00 i sal D2 KTH, Lindstedtsvägen 5, Stockholm. iii Messen ist wissen, aber messen ohne Wissen ist kein Wissen Werner von Siemens Å meta e å veta Som man säger på den Kungliga Tekniska Högskolan i Hufvudstaden Att mäta är att väta Som man säger i dykeriforskning Till min familj Olivia, Artur och Filip iv v Abstract The present series of unmanned hyperbaric tests were conducted in order to investigate the oxygen fraction variability in semi-closed underwater rebreathing apparatuses. The tested rebreathers were RB80 (Halcyon dive systems, High springs, FL, USA), IS-Mix (Interspiro AB, Stockholm, Sweden), CRABE (Aqua Lung, Carros Cedex, France), and Viper+ (Cobham plc, Davenport, IA, USA). The tests were conducted using a catalytically based propene combusting metabolic simulator. The metabolic simulator connected to a breathing simulator, both placed inside a hyperbaric pressure chamber, was first tested to demonstrate its usefulness to simulate human respiration in a hyperbaric situation.
    [Show full text]
  • Hyperoxia Induces Glutamine-Fuelled Anaplerosis in Retinal Mã¼ller Cells
    ARTICLE https://doi.org/10.1038/s41467-020-15066-6 OPEN Hyperoxia induces glutamine-fuelled anaplerosis in retinal Müller cells Charandeep Singh 1, Vincent Tran1, Leah McCollum1, Youstina Bolok1, Kristin Allan1,2, Alex Yuan1, ✉ George Hoppe1, Henri Brunengraber3 & Jonathan E. Sears 1,4 Although supplemental oxygen is required to promote survival of severely premature infants, hyperoxia is simultaneously harmful to premature developing tissues such as in the retina. 1234567890():,; Here we report the effect of hyperoxia on central carbon metabolism in primary mouse Müller glial cells and a human Müller glia cell line (M10-M1 cells). We found decreased flux from glycolysis entering the tricarboxylic acid cycle in Müller cells accompanied by increased glutamine consumption in response to hyperoxia. In hyperoxia, anaplerotic catabolism of glutamine by Müller cells increased ammonium release two-fold. Hyperoxia induces glutamine-fueled anaplerosis that reverses basal Müller cell metabolism from production to consumption of glutamine. 1 Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA. 2 Molecular Medicine, Case Western Reserve School of Medicine Cleveland, Cleveland, OH 44106, USA. 3 Department of Nutrition, Case Western Reserve School of Medicine Cleveland, Cleveland, OH 44106, USA. ✉ 4 Cardiovascular and Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA. email: [email protected] NATURE COMMUNICATIONS | (2020) 11:1277 | https://doi.org/10.1038/s41467-020-15066-6 | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-020-15066-6 remature infants require oxygen supplementation to sur- We first ensured that the isotopic steady state was established for Pvive, but excess oxygen causes retinovascular growth sup- at least 20 h before treating part of the cells with hyperoxia.
    [Show full text]
  • Moderate Intermittent Hypoxia/Hyperoxia: Implication for Correction of Mitochondrial Dysfunction
    Cent. Eur. J. Biol. • 7(5) • 2012 • 801-809 DOI: 10.2478/s11535-012-0072-x Central European Journal of Biology Moderate intermittent hypoxia/hyperoxia: implication for correction of mitochondrial dysfunction Research Article Olga A. Gonchar*, Irina N. Mankovska Department of Hypoxic States, Bogomoletz Institute of Physiology National Academy of Sciences of Ukraine, 01024 Kiev, Ukraine Received 26 January 2012; Accepted 06 June 2012 Abstract: The purpose of this study was to appreciate the acute hypoxia-induced mitochondrial oxidative damage development and the role of adaptation to hypoxia/hyperoxia (H/H) in correction of mitochondrial dysfunction. It was demonstrated that long-term sessions of moderate H/H [5 cycles of 5 min hypoxia (10% O2 in N2) alternated with 5 min hyperoxia (30% O2 in N2) daily for two weeks] attenuated 2+ basal and Fe /ascorbate-induced lipid peroxidation (LPO) as well as production of carbonyl proteins and H2O2 in liver mitochondria of rats exposed to acute severe hypoxia (7% O2 in N2, 60 min) in comparison with untreated animals. It was shown that H/H increases the activity of glutathione peroxidase (GPx), reduces hyperactivation of Mn-SOD, and decreases Cu,Zn- SOD activity as compared with untreated rats. It has been suggested that the induction of Mn-SOD protein expression and the coordinated action of Mn-SOD and GPx could be the mechanisms underlying protective effects of H/H, which promote the correction of the acute hypoxia- induced mitochondrial dysfunction. The increase in Mn-SOD protein synthesis without changes in Mn-SOD mRNA level under H/H pretreatment indicates that the Mn-SOD activity is most likely dependent on its posttranslational modification or on the redox state of liver mitochondria.
    [Show full text]
  • Physical Therapy Practice and Mechanical Ventilation: It's
    Physical Therapy Practice and Mechanical Ventilation: It’s AdVENTageous! Lauren Harper Palmisano, PT, DPT, CCS Rebecca Medina, PT, DPT, CCS Bob Gentile, RRT/NPS OBJECTIVES After this lecture you will be able to describe: 1. Indications for Mechanical Ventilation 2. Basic ventilator anatomy and purpose 3. Ventilator Modes, variables, and equations 4. Safe patient handling a. Alarms and what to expect b. Considerations for mobilization 5. Ventilator Liberation 6. LAB: Suctioning with Bob! INDICATIONS FOR MECHANICAL VENTILATION Cannot Ventilate Cannot Respirate Ventilation: the circulation of air Respiration: the movement of O2 from the outside environment to the cellular level, and the diffusion of Airway protection CO2 in the opposite direction ● Sedation ● Inflammation Respiratory Failure/Insufficiency ● Altered mental status ●Hypercarbic vs Hypoxic ●Vent will maintain homeostasis of CO2 and O2 ●Provides pressure support in the case of fatigued muscles of ventilation VENTILATOR ANATOMY ● Power supply/no battery ● O2 supply and Air supply ● Inspiratory/Expiratory Tubes ● Flow Sensor ● Ventilator Home Screen ● ET tube securing device- hollister ● Connection points - ET tube and trach HOME SCREEN What to observe: ● Mode ● Set rate ● RR ● FiO2 ● PEEP ● Volumes ● Peak and plateau pressures HOME SCREEN ● Mode ● Set rate ● RR ● FiO2 ● PEEP ● Volumes ● Peak and plateau pressures VENTILATION VARIABLES, EQUATIONS, & MODES Break it down ... VARIABLES IN DELIVERY Volume Flow (speed of volume delivery) in L/min Closed loop system ● No flow adjustment
    [Show full text]
  • Intracerebral Hemorrhage Related to Systemic Gas Embolism During Hysteroscopy
    UHM 2010, Vol. 37, No. 2 – Intracerebral hemorrhage in systemic gas embolism Intracerebral hemorrhage related to systemic gas embolism during hysteroscopy EMILIE GUILLARD, BÉNÉDICTE NANCY, HERVÉ FLOCH, ANNE HENCKES, GUY COCHARD, JOSIANE ARVIEUX, CHARLES CHRISTIAN ARVIEUX CHU Brest, Pôle Anesthesiology Intensive Care SAMU, Department of Anesthesiology and Intensive Care, Center for Hyperbaric Medicine, Brest, F-29200 France CORRESPONDING AUTHOR: Dr. Guy Cochard – [email protected] ABSTRACT Iatrogenic gas embolism is a rare but serious problem that has been documented in almost all medical specialties including gynecology. We present a 49-year-old woman undergoing operative hysteroscopy and myomectomy, who sustained sudden hypotension and decrease in the end-tidal carbon dioxid levels during the procedure. Systemic gas embolism was confirmed by echocardiographic evidence of bubbles in both right and left cardiac cavities and a rise of troponin. Hyperbaric oxygen was rapidly administered in addition to maintenance of vital functions and anti-thrombotic prevention with calciparin. A right hemiparesis was apparent after recovery from general anesthesia. Brain-computed tomography and magnetic resonnance imaging, performed on Days 3 and 2 respectively, showed a left fronto-parietal hematoma surrounded by edema. Having ruled out risk factors for a primary ischemic or hemorrhagic stroke, we concluded that hemorragic transformation of the ischemic cerebral lesion caused by gas embolism was responsible for the observed intraparenchymal hematoma. As far as we know, this is the first report relating cerebral gas embolism with an intracerebral hemorrhage. It provides an argument against anticoagulant therapy during the early stages of gas embolism care. INTRODUCTION transthoracic echocardiography. Cerebral imaging Air and gas embolism have been reported in almost studies demonstrated a single intraparenchymal all areas of clinical and surgical practice, including hematoma, consistent with the hemorrhagic operative hysteroscopy (1-3).
    [Show full text]
  • Misleading Hyperoxia Test
    Arch Dis Child: first published as 10.1136/adc.61.6.604 on 1 June 1986. Downloaded from 604 Archives of Disease in Childhood, 1986, 61 Misleading hyperoxia test A M C ENRIQUES, R McKAY, R M ARNOLD, AND J L WILKINSON The Royal Liverpool Children's Hospital, Liverpool carbon dioxide tension steadily increased. Chest SUMMARY A 2 day old infant with infracardiac total x ray films eventually showed bilateral diffuse anomalous pulmonary venous connection achieved opacities, and the hyperoxia test was repeated at 17 an arterial oxygen tension > 250 mmHg, breathing days. On this occasion, arterial oxygen tension 100% oxygen. Diagnosis of cardiac disease was increased only to 75 mmHg, and the patient was delayed several weeks. The anatomical basis for this referred for cardiac investigation. phenomenon was streaming of systemic venous On admission, the respiratory rate was 70 breaths return across an inferior vena cava type atrial septal per minute with intercostal recession and mild defect. central cyanosis. The second heart sound was single and accentuated, but no murmurs could be heard. Cardiorespiratory distress in the newborn infant may result from a variety of disorders. The hyper- oxia or nitrogen washout test is widely used and claimed to be a sensitive and accurate discriminator between cyanotic and acyanotic cardiac lesions and pulmonary disease. 1 An oxygen tension greater than 250 mmHg in an arterial sample from the right arm copyright. after 100% oxygen has been administered for 5-10 minutes is said to exclude cyanotic heart disease;2 while a value of more than 150 mmHg makes its occurrence extremely unlikely.3 In the patient presented here, however, a combination of factors obscured the typical presentation of a common mixing type, cyanotic heart lesion.
    [Show full text]
  • Oxygen Administration in Patients Recovering from Cardiac Arrest: a Narrative Review Ryo Yamamoto* and Jo Yoshizawa
    Yamamoto and Yoshizawa Journal of Intensive Care (2020) 8:60 https://doi.org/10.1186/s40560-020-00477-w REVIEW Open Access Oxygen administration in patients recovering from cardiac arrest: a narrative review Ryo Yamamoto* and Jo Yoshizawa Abstract High oxygen tension in blood and/or tissue affects clinical outcomes in several diseases. Thus, the optimal target PaO2 for patients recovering from cardiac arrest (CA) has been extensively examined. Many patients develop hypoxic brain injury after the return of spontaneous circulation (ROSC); this supports the need for oxygen administration in patients after CA. Insufficient oxygen delivery due to decreased blood flow to cerebral tissue during CA results in hypoxic brain injury. By contrast, hyperoxia may increase dissolved oxygen in the blood and, subsequently, generate reactive oxygen species that are harmful to neuronal cells. This secondary brain injury is particularly concerning. Although several clinical studies demonstrated that hyperoxia during post-CA care was associated with poor neurological outcomes, considerable debate is ongoing because of inconsistent results. Potential reasons for the conflicting results include differences in the definition of hyperoxia, the timing of exposure to hyperoxia, and PaO2 values used in analyses. Despite the conflicts, exposure to PaO2 > 300 mmHg through administration of unnecessary oxygen should be avoided because no obvious benefit has been demonstrated. The feasibility of titrating oxygen administration by targeting SpO2 at approximately 94% in patients recovering from CA has been demonstrated in pilot randomized controlled trials (RCTs). Such protocols should be further examined. Keywords: Cardiac arrest, Post cardia arrest syndrome, Oxygen, Hyperoxia, Hypoxic brain injury Background indicates that the initiation of oxygen treatment and the Many patients develop hypoxic brain injury after the re- amount of oxygen should be deliberately decided.
    [Show full text]
  • Lipid Peroxidation in Newborn Rabbits: Effects of Oxygen, Lipid Emulsion, and Vitamin El
    003 1-3998/86/2006-0505$02.00/0 PEDIATRIC RESEARCH Vol. 20, No. 6, 1986 Copyright O 1986 International Pediatric Research Foundation, Inc. Printed in U.S.A. Lipid Peroxidation in Newborn Rabbits: Effects of Oxygen, Lipid Emulsion, and Vitamin El JON R. WISPE,~MATTHEW KNIGHT,' AND ROBERT J. ROBERTS Division of Neonatology, Department of Pediatrics, University of lowa, College of Medicine, Iowa City, Iowa 52242 ABSTRACT. The extent of in vivo lipid peroxidation and with hyperoxic exposure, including bronchopulmonary dysplasia the in vivo antioxidant effects of a-tocopherol and a- and retrolental fibroplasia. tocopheryl acetate were studied in newborn rabbits exposed The exact mechanism by which oxidant tissue damage occurs to one of two oxidant stresses: hyperoxia (FIO~>0.9) or is not clear. Several lines of evidence support the hypothesis that parenteral lipid emulsion infusion. Lipid peroxidation was oxidant injury is mediated by the generation of partially reduced monitored by measurement of expired ethane and pentane, oxygen species (1-3). These reactive species may damage tissues tissue thiobarbituric acid (TBA) reactants, and tissue lipid by peroxidation of lipids, oxidation of proteins and nucleic acids, peroxides. Seventy-two h of hyperoxia did not increase any or through yet undefined mechanisms. It has long been presumed of the parameters of lipid peroxidation although mortality that polyunsaturated fatty acids in membranes are particularly was higher in oxygen exposed animals. a-Tocopherol (100 susceptible to oxidative processes, and that "lipid peroxidation" mg/kg, intravenous) lowered expired hydrocarbons and is a central feature of oxygen-associated tissue damage. Lipid tissue TBA reactants, but raised liver lipid peroxides in peroxidation is associated with the generation of lipid-derived both air and hyperoxia exposed pups.
    [Show full text]