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Ning Y, Cheng S, Wang JX, Liu YW, Feng W, Li F, Zhang JL. Fluorescence lifetime imaging of upper gastrointestinal pH in vivo with a lanthanide based near-infrared τ probe. Chem Sci 2019; 10:4227-4235. [PMID: 31057751 PMCID: PMC6471977 DOI: 10.1039/c9sc00220k] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 02/23/2019] [Indexed: 12/27/2022] Open
Abstract
Lanthanide complex was successfully applied in the design of pH-responsive NIR τ probe for quantitative in vivo imaging.
Time-resolved fluorescence lifetime imaging (FLIM) in the near-infrared region of 900–1700 nm not only allows a deep tissue penetration depth but also offers the unique benefit of the quantitative visualization of molecular events in vivo and is independent of local luminescence intensity and fluorophore concentration. Herein, we report the design of a wide-range pH sensitive molecular probe based on Yb3+ porphyrinate. The Yb3+ probe shows increasing NIR emission and lifetime with pKa values of ca. 6.6 from pH 9.0 and 5.0 and also displays an elongated lifetime from ca. 135 to 170 μs at lower pH values (5.0–1.0) due to aggregation and reduced exposure to water at low pH values. Importantly, the probe is able to monitor a wide range of in vivo gastrointestinal pH values in mice models and the potential applications in imaging-guided gastrointestinal diagnostics and therapeutics were revealed. This study shows that lifetime contrast is important for preclinical imaging; lanthanide complexes could be successfully used in the design of stimuli-responsive NIR τ probes for advanced in vivo imaging.
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Affiliation(s)
- Yingying Ning
- Beijing National Laboratory for Molecular Sciences , State Key Laboratory of Rare Earth Materials Chemistry and Applications , College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , P. R. China .
| | - Shengming Cheng
- Department of Chemistry , State Key Laboratory of Molecular Engineering of Polymers , Institutes of Biomedical Sciences , Fudan University , Shanghai 200433 , P. R. China
| | - Jing-Xiang Wang
- Beijing National Laboratory for Molecular Sciences , State Key Laboratory of Rare Earth Materials Chemistry and Applications , College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , P. R. China .
| | - Yi-Wei Liu
- Beijing National Laboratory for Molecular Sciences , State Key Laboratory of Rare Earth Materials Chemistry and Applications , College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , P. R. China .
| | - Wei Feng
- Department of Chemistry , State Key Laboratory of Molecular Engineering of Polymers , Institutes of Biomedical Sciences , Fudan University , Shanghai 200433 , P. R. China
| | - Fuyou Li
- Department of Chemistry , State Key Laboratory of Molecular Engineering of Polymers , Institutes of Biomedical Sciences , Fudan University , Shanghai 200433 , P. R. China
| | - Jun-Long Zhang
- Beijing National Laboratory for Molecular Sciences , State Key Laboratory of Rare Earth Materials Chemistry and Applications , College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , P. R. China .
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Abstract
A specific device and system has been developed and tested for clinical monitoring of gastric mucosal reactance in the critically ill as an early warning of splanchnic hypoperfusion associated with shock and sepsis. This device has been proven effective in clinical trials and is expected to become commercially available next year. The system uses a combination nasogastric tube and impedance spectroscopy probe as a single catheter. Because this device has a double function, the question is: Does enteral feeding or suction affect the gastric reactance measurements? This study was designed to evaluate the effect of feeding and suction on the measurement of gastric impedance spectroscopy in healthy volunteers. Impedance spectra were obtained from the gastric wall epithelia of 18 subjects. The spectra were measured for each of the following conditions: postinsertion of gastric probe, during active suction, postactive suction, and during enteral feeding (236 ml of nutritional supplement). Impedance spectra were reproducible in all volunteers under all conditions tested. There was a slight increase in impedance parameters after suction, and a decrease in impedance after feeding; however, these observed differences were insignificant compared to patient-to-patient variability, and truly negligible compared with previously observed changes associated with splanchnic ischemia in critically ill patients. Our results demonstrate that suction or feeding when using the impedance spectro-metry probe/nasogastric tube does not significantly interfere with gastric impedance spectrometer measurements.
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Streefkerk JO, Beishuizen A, Groeneveld ABJ. Gastric feeding intolerance is not caused by mucosal ischemia measured by intragastric air tonometry in the critically ill. Clin Nutr 2015; 35:731-4. [PMID: 26082336 DOI: 10.1016/j.clnu.2015.05.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 05/09/2015] [Accepted: 05/22/2015] [Indexed: 11/17/2022]
Abstract
BACKGROUND Gastric mucosal ischemia may be a risk factor for gastrointestinal intolerance to early feeding in the critically ill. AIMS To study intragastric PCO2 air tonometry and gastric residual volumes (GRV) before and after the start of gastric feeding. METHODS This is a two-center study in intensive care units of a university and teaching hospital. Twenty-nine critically ill, consecutive and consenting patients scheduled to start gastric feeding were studied after insertion of a gastric tonometry catheter and prior to and after start of gastric feeding (500 ml over 1 h), when clinically indicated. RESULTS Blood gasometry and intragastric tonometry were performed prior to and 2 h after gastric feeding. The intragastric to arterial PCO2 gap (normal <8 mm Hg) was elevated in 41% of patients prior to feeding and measured (mean ± standard deviation) 13 ± 20 and 16 ± 23 mm Hg in patients with normal (<100 ml, 42 ± 34 ml, n = 19) and elevated GRV (250 ± 141 ml, n = 10, P = 0.75), respectively. After feeding, the gradient did not increase and measured 27 ± 25 and 23 ± 34 mm Hg, respectively (P = 0.80). CONCLUSION Gastric mucosal ischemia is not a major risk factor for intolerance to early gastric feeding in the critically ill.
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Affiliation(s)
- Jörn O Streefkerk
- Department of Intensive Care Medisch Centrum Haaglanden and Bronovo Ziekenhuis, Den Haag, Rotterdam, The Netherlands
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Upadhyay KK, Singh VP, Murthy T. Gastric Tonometry as a Prognostic Index of Mortality in Sepsis. Med J Armed Forces India 2011; 63:337-40. [PMID: 27408044 DOI: 10.1016/s0377-1237(07)80010-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Accepted: 06/20/2007] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Splanchnic hypoperfusion in sepsis leads to translocation of bacteria from gut and development of multi-organ dysfunction syndrome (MODS), with increased mortality in critically ill patients. Gastric tonometry can detect this hypoperfusion by measuring carbon dioxide tension (PgCO2) and intramucosal pH (pHi) from gastric mucosa. Therapeutic intervention aimed at improving gut perfusion can improve the outcome and prognosticate the mortality in sepsis patients. METHODS 100 patients with clinical diagnosis of sepsis were included and divided into two groups of 50 each. Group A patients were managed traditionally without gastric tonometry and in Group B gastric tonometry was used for therapeutic intervention. The intramucosal PCO2, pHi, end tidal carbon dioxide tension (EtCO2) and (PgCO2-EtCO2) differences were monitored at 0, 12 and 24 hours interval. RESULT Overall mortality in Group A was 64 % and 54 % in Group B. In Group B 45% patients developed MODS and 54 % died with low pHi. As an index of mortality low pHi had a sensitivity of 70% and specificity of 65%. CONCLUSION There is a good correlation between mortality prediction on the basis of pHi and PgCO2-EtCO2 difference and actual mortality in critically ill patients. The gastric tonometer should be used to predict mortality and guide resuscitation in septicemia.
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Affiliation(s)
- K K Upadhyay
- Associate Professor (Department of Anaesthesiology and Critical Care), Armed Forces Medical College, Pune-411040
| | - V P Singh
- ADMS, HQ Western Command, Army Hospital (R&R), Delhi Cantt
| | - Tvsp Murthy
- Senior Advisor (Neuroanaesthesia), Army Hospital (R&R), Delhi Cantt
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Thibault R, Pichard C, Wernerman J, Bendjelid K. Cardiogenic shock and nutrition: safe? Intensive Care Med 2010; 37:35-45. [DOI: 10.1007/s00134-010-2061-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 09/09/2010] [Indexed: 12/17/2022]
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Olsen KM, Devlin JW. Comparison of the enteral and intravenous lansoprazole pharmacodynamic responses in critically ill patients. Aliment Pharmacol Ther 2008; 28:326-33. [PMID: 19086331 DOI: 10.1111/j.1365-2036.2008.03728.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND While proton pump inhibitors are frequently administered in the intensive care unit, the pharmacodynamic response of acid suppression between the enteral and intravenous (IV) route is unknown. AIM To compare the pharmacodynamic response between enteral and IV lansoprazole in intensive care unit patients requiring stress ulcer prophylaxis therapy. METHODS Adult mechanically ventilated patients were randomized to receive 72 h of daily enteral [lansoprazole oral disintegrating tablet (LODT) 30 mg mixed in 10 mL of water via a nasal gastric tube] or IV lansoprazole (30 mg over 30 min) therapy. Serial blood samples were collected after the first and third dose and analysed for pharmacokinetic parameters. Pharmacodynamic determination of intragastric pHmetry began prior to the first dose and continued for 72 h using a single channel pH microelectrode. RESULTS Nineteen intensive care unit patients were randomized [LODT (n = 10); IV-L (n = 9)]. LODT bioavailability was 76%. LODT maintained gastric pH > 4 longer than IV-L at both 24 h (7.4 vs. 5.9 h; P = 0.039) and 72 h (10.4 and 8.9 h; P = 0.046) and resulted in a greater average pH over the first 24 h (3.67 vs. 2.89; P = 0.03). CONCLUSION Despite a lower bioavailability, enteral lansoprazole suppresses acid in intensive care unit patients to a greater extent than IV lansoprazole.
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Affiliation(s)
- K M Olsen
- College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, USA.
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Cancio LC, Kuwa T, Matsui K, Drew GA, Galvez E, Sandoval LL, Jordan BS. Intestinal and gastric tonometry during experimental burn shock. Burns 2007; 33:879-84. [PMID: 17532145 DOI: 10.1016/j.burns.2006.11.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2006] [Accepted: 11/26/2006] [Indexed: 11/25/2022]
Abstract
INTRODUCTION The occurrence of organ failure following thermal injury, despite restoration of hemodynamic parameters and urine output during resuscitation, has led to efforts to measure end-organ perfusion. The purpose of this 24-h study was to evaluate the utility of gastrointestinal (GI) tonometry during burn shock and resuscitation. METHODS Male swine (n=11, 23.3+/-0.9 kg) were anesthetized with ketamine and propofol. A 70% full thickness burn was caused by immersion in 97 degrees C water for 30 s. Resuscitation with lactated Ringer's, 4 ml/kg/% burn, was begun at hour 6 and titrated to urine output (UO). Arterial blood gases and pulmonary artery catheter data were measured every 6 h. Gastric and ileal regional PCO(2) (PrCO(2)) were measured continuously by air tonometry, and the gastric and ileal intramucosal pH (pHi) and PCO(2) gap (PrCO(2)-PaCO(2)) were calculated every 6 h. RESULTS Gastric pHi, ileal PrCO(2), ileal pHi, and ileal PCO(2) gap (but not gastric PrCO(2) or PCO(2) gap) all decreased with shock and were restored to baseline levels by resuscitation. Changes in ileal PrCO(2) were of greater magnitude and demonstrated decreased variability than those in gastric PrCO(2). CONCLUSIONS In this model, ileal tonometry outperformed gastric tonometry during burn shock and resuscitation.
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Affiliation(s)
- Leopoldo C Cancio
- U.S. Army Institute of Surgical Research, 3400 Rawley E. Chambers Avenue, Fort Sam Houston, TX 78234-6315, USA.
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Knotzer H, Hasibeder WR. Microcirculatory function monitoring at the bedside--a view from the intensive care. Physiol Meas 2007; 28:R65-86. [PMID: 17827646 DOI: 10.1088/0967-3334/28/9/r01] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Microcirculatory dysfunction plays a key role in the pathophysiology of various disease states and may consequently impact patient outcome. Until recently, the evaluation of the microcirculation using different measurement techniques has been mostly limited to animal and human research. With technical advances, microcirculatory monitoring nowadays becomes more and more available for application in clinical praxis. Unfortunately, measurements within the microcirculation are mostly limited to easily accessible surfaces, such as skin, muscle and tongue. Due to major differences in the physiologic regulation of microcirculatory blood flow and in metabolism between organs and even within different tissues in one organ, the clinical importance of regional microcirculatory measurements remains to be determined. In addition, technical methods available demonstrate large differences in the measured parameters and sampling volume, making interpretation of data even more difficult. Nonetheless, the monitoring of the microcirculation may, ahead of time, alert physicians that tissue oxygen supply becomes compromised and it may lead to a better understanding of basic pathophysiological aspects of disease. In the present review, we describe available non-invasive microcirculatory measurement techniques which can be applied clinically at the bedside. After a short discussion of physiologic and pathophysiologic basics related to microcirculatory monitoring, the measuring principles, applications, strengths and limitations of different monitoring systems are discussed.
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Affiliation(s)
- Hans Knotzer
- Department of Anesthesiology and Critical Care Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria.
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Antonelli M, Levy M, Andrews PJD, Chastre J, Hudson LD, Manthous C, Meduri GU, Moreno RP, Putensen C, Stewart T, Torres A. Hemodynamic monitoring in shock and implications for management. International Consensus Conference, Paris, France, 27-28 April 2006. Intensive Care Med 2007; 33:575-90. [PMID: 17285286 DOI: 10.1007/s00134-007-0531-4] [Citation(s) in RCA: 261] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Accepted: 01/05/2007] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Shock is a severe syndrome resulting in multiple organ dysfunction and a high mortality rate. The goal of this consensus statement is to provide recommendations regarding the monitoring and management of the critically ill patient with shock. METHODS An international consensus conference was held in April 2006 to develop recommendations for hemodynamic monitoring and implications for management of patients with shock. Evidence-based recommendations were developed, after conferring with experts and reviewing the pertinent literature, by a jury of 11 persons representing five critical care societies. DATA SYNTHESIS A total of 17 recommendations were developed to provide guidance to intensive care physicians monitoring and caring for the patient with shock. Topics addressed were as follows: (1) What are the epidemiologic and pathophysiologic features of shock in the ICU? (2) Should we monitor preload and fluid responsiveness in shock? (3) How and when should we monitor stroke volume or cardiac output in shock? (4) What markers of the regional and micro-circulation can be monitored, and how can cellular function be assessed in shock? (5) What is the evidence for using hemodynamic monitoring to direct therapy in shock? One of the most important recommendations was that hypotension is not required to define shock, and as a result, importance is assigned to the presence of inadequate tissue perfusion on physical examination. Given the current evidence, the only bio-marker recommended for diagnosis or staging of shock is blood lactate. The jury also recommended against the routine use of (1) the pulmonary artery catheter in shock and (2) static preload measurements used alone to predict fluid responsiveness. CONCLUSIONS This consensus statement provides 17 different recommendations pertaining to the monitoring and caring of patients with shock. There were some important questions that could not be fully addressed using an evidence-based approach, and areas needing further research were identified.
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Affiliation(s)
- Massimo Antonelli
- Istituto di Anestesiologia e Rianimazione, Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Largo A. Gemelli, 8, 00168 Rome, Italy
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Englehart MS, Schreiber MA. Measurement of acid-base resuscitation endpoints: lactate, base deficit, bicarbonate or what? Curr Opin Crit Care 2007; 12:569-74. [PMID: 17077689 DOI: 10.1097/mcc.0b013e328010ba4f] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW Inadequate oxygen delivery to the tissues frequently results in significant metabolic acidosis. The resultant cellular and organ dysfunction can increase morbidity, mortality and hospital stay. Early diagnosis of shock can lead to early resuscitation efforts that can prevent ongoing tissue injury. This review focuses on the metabolic, hemodynamic and regional perfusion endpoints utilized in the diagnosis of metabolic acidosis resulting from shock. Resuscitation strategies aimed at supranormal oxygen delivery will be discussed. RECENT FINDINGS Serum pH, lactate, base deficit and bicarbonate have all been extensively studied as clinical markers of metabolic acidosis in shock. While their trend helps guide resuscitation, no single marker or specific value can be utilized to guide resuscitation for all patients. Hemodynamic parameters and regional tissue endpoints are designed to identify compensated shock before it progresses to uncompensated shock. Resuscitation strategies initiated in the early phases of shock can reduce complications and death. Efforts to resuscitate patients to supranormal oxygen delivery endpoints have demonstrated mixed success, with several notable complications. SUMMARY Despite the large number of endpoints available to the clinician, none are universally applicable and none have independently demonstrated improved survival when guiding resuscitation. Patients who respond well to initial resuscitation efforts demonstrate a survival advantage over nonresponders.
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Affiliation(s)
- Michael S Englehart
- Department of Surgery, Oregon Health & Science University, Portland, Oregon 91239, USA
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Kushi H, Miki T, Nakahara J, Okamoto K, Kawahara Y, Saito T, Tanjoh K. Hemoperfusion with an immobilized polymyxin B fiber column improves tissue oxygen metabolism. Ther Apher Dial 2007; 10:430-5. [PMID: 17096698 DOI: 10.1111/j.1744-9987.2006.00407.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Recently, direct hemoperfusion with a polymyxin B-coated fiber column (DHP-PMX) has been increasingly used for the treatment of sepsis, and an improvement in outcomes has been reported. However, the mechanism of the method is not known in detail. In the present study, we examined whether the performance of DHP-PMX improved tissue oxygen metabolism in patients with sepsis. Twenty-two patients with sepsis, satisfying the following criteria, were enrolled in the study: (i) signs of systemic inflammatory response syndrome caused by infection; and (ii) mean arterial blood pressure > or =60 mm Hg (irrespective of the use of catecholamines). A thermodilution catheter was inserted prior to DHP-PMX for appropriate intravenous infusion, and the DHP-PMX was carried out twice within 24 h (for 3 h each time). Then, the gastric mucosal-arterial PCO(2) difference (PCO(2) gap) was calculated as the gastric mucosal PCO(2) minus arterial PCO(2). A PCO(2) gap > or =8 mm Hg was used to define abnormal tissue oxygen metabolism. PCO(2) gap was measured before PMX-DHP, as well as 24, 48, and 72 h afterward. PCO(2) gap was 20 +/- 4.9 mm Hg before DHP-PMX vs. 16 +/- 2.7 mm Hg (P = 0.189) at 24 h, 12 +/- 2.8 mm Hg (P = 0.046) at 48 h, and 11 +/- 2.2 mm Hg (P = 0.045) at 72 h afterward, showing a significant decrease from 48 h onward compared with before treatment. These findings suggest that DHP-PMX improves tissue oxygen metabolism.
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Affiliation(s)
- Hidehiko Kushi
- Department of Emergency and Critical Care Medicine, Nihon University School of Medicine, Tokyo, Japan.
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Abstract
PURPOSE OF REVIEW Tissue hypoperfusion is a common pathophysiologic process leading to multiple organ dysfunction and death. Increases in tissue PCO2 can reflect an abnormal oxygen supply to the cells, so that monitoring tissue PCO2 by the use of gastric or sublingual capnometry may help identify circulatory abnormalities and guide their correction. This review provides an update on these technologies. RECENT FINDINGS Gastric tonometry aims at monitoring PCO2 in the stomach, an organ that becomes ischemic quite early when the circulatory status is jeopardized. Despite substantial initial enthusiasm, this technique has never been widely implemented due to methodological problems. The measurement of sublingual mucosal PCO2 (PslCO2) by sublingual capnometry is technically simple and noninvasive. Experimental studies have suggested that PslCO2 is a reliable marker of tissue perfusion. Clinical studies have demonstrated that high PslCO2 values are associated with impaired microcirculatory blood flow and a worse prognosis in critically ill patients. SUMMARY Gastric tonometry was proposed for regional PCO2 monitoring, but it is prone to a number of technical limitations. Sublingual capnometry could offer a valuable alternative for tissue PCO2 monitoring in clinical practice, representing a simple, noninvasive method to monitor tissue perfusion and titrate therapeutic interventions in critically ill patients.
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Affiliation(s)
- Jacques Creteur
- Department of Intensive Care, Erasme University Hospital, Free University of Brussels, Belgium.
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Abstract
Microcirculatory dysfunctions play a central role in the pathophysiology of sepsis and shock. Modern methods enable microvascular monitoring in man and offer the possibility to test the effect of novel therapeutical strategies for sepsis. Furthermore, these techniques may be future tools for the monitoring of critically ill patients. In this review, we will describe four microvascular monitoring devices and give an overview of the microcirculatory changes observed during the course of sepsis. Laser Doppler fluxmetry is an easy to use noninvasive technique to measure tissue perfusion enabling monitoring of the effect of different catecholamines on the gastric perfusion during sepsis. Increased microvascular permeability and altered blood flow in septic patients can be quantified by venous congestion plethysmography. Alterations in sublingual microvascular blood flow are detected by intravital microscopy in septic patients and were identified as an outcome predictor. Furthermore, the role of gastrointestinal pCO2-tonometry for microcirculatory monitoring of the perfusion of splanchnic organs during sepsis is discussed. The true clinical value of these techniques has yet to be established and will depend on larger clinical trials showing an impact on diagnostics and patient management.
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Affiliation(s)
- A Bauer
- Klinik für Anaesthesiologie, Klinikum der Universität München-Grosshadern, Marchioninistrasse 15, 81377 München-Grosshadern
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Affiliation(s)
- Elizabeth J. Bridges
- Elizabeth Bridges was formerly the deputy commander of the 59th Clinical Research Squadron and a senior nurse researcher at the 59th Medical Wing, Lackland Air Force Base, San Antonio, Tex. She is now an assistant professor at the University of Washington School of Nursing and a clinical nurse researcher at the University of Washington Medical Center, Seattle, Wash
| | - Susan Dukes
- Susan Dukes is a critical care clinical nurse specialist in the 759th Surgical Operations Squadron, Wilford Hall Medical Center, at Lackland Air Force Base
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Marshall AP, West SH. Gastric tonometry and monitoring gastrointestinal perfusion: using research to support nursing practice. Nurs Crit Care 2004; 9:123-33. [PMID: 15152754 DOI: 10.1111/j.1478-5153.2004.00056.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The principles and physiological underpinnings of gastric tonometry are reviewed. Tonometric variables, including the PtCO2, pHi and CO2 gap, are described and critiqued as measurements of gastrointestinal perfusion. Increases in gastrointestinal CO2 unrelated to gastrointestinal hypoperfusion are discussed within different clinical contexts. The technical limitations of gastric tonometry, including procedural errors and PtCO2 measurement are discussed in relation to the accuracy of tonometric measurements. Tonometric measurement using semi-continuous air tonometry is introduced as a strategy to minimize technical limitations.
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Affiliation(s)
- Andrea P Marshall
- Department of Clinical Nursing, The University of Sydney, Sydney, Australia.
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Thorburn K, Durward A, Tibby SM, Murdoch IA. Effects of feeding on gastric tonometric measurements in critically ill children. Crit Care Med 2004; 32:246-9. [PMID: 14707587 DOI: 10.1097/01.ccm.0000104115.03922.ac] [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] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine the effect of gastric feeding on the measurement of gastric intramucosal PCO2 (PiCO2) and its derived gastric intramucosal PCO2-arterial PCO2 difference (PiCO2-PaCO2 difference) and gastric intramucosal pH (pHi) in a group of critically ill children using recirculating gas tonometry. DESIGN Prospective clinical pilot study. SETTING Sixteen bed pediatric intensive care unit. PATIENTS Ten mechanically ventilated and hemodynamically stable children (median age, 20.1 months [interquartile range (IQR), 9.7-47.6 months] and median weight, 10.2 kg [IQR, 10-16.5 kg]). INTERVENTIONS A 7-French recirculating gas tonometer was placed in the stomach via the orogastric route. MEASUREMENTS In each patient, baseline fasted/unfed PiCO2, PiCO2-PaCO2 difference, and pHi were determined hourly over a 5-hr period. Gastric feeding was then reestablished (3 mL/kg/hr) within a median time of 3 hrs and a further 5 hourly measurements were determined. Concurrent arterial blood gas and lactate measurements were taken. Blood pressure and heart rate was monitored throughout. MAIN RESULTS Hemodynamic parameters remained stable throughout the study period. When compared with the unfed/fasting state, PiCO2 measurements and PiCO2-PaCO2 difference were consistently lower and pHi values higher than when the patients were fed (two-way analysis of variance for repeated measures: all p <.001 between groups). Measurements did not vary over time. CONCLUSIONS In our patient group, gastric feeding decreased the PiCO2 and PiCO2-PaCO2 difference and increased pHi compared with the unfed state. These findings are in contrast to those found in adult studies.
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Affiliation(s)
- Kentigern Thorburn
- Department of Paediatric Intensive Care, Royal Liverpool Children's Hospital-Alder Hey, UK
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Marshall AP, West SH. Gastric Tonometry and Enteral Nutrition: a Possible Conflict in Critical Care Nursing Practice. Am J Crit Care 2003. [DOI: 10.4037/ajcc2003.12.4.349] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
• Background Gastric tonometry is used to assess gastrointestinal mucosal perfusion in critically ill patients. However, enteral feeding is withheld during monitoring with gastric tonometry because enteral feeding is thought to influence tonometric measurements.• Objectives To examine the effect of enteral feeding on the tonometric measurement of gastric mucosal carbon dioxide.• Methods Gastric tonometers were placed in 20 critically ill patients, and the Pco2 of the gastric mucosa was measured in both the full and the empty stomach during a 48-hour period.• Results The Pco2 measured by the tonometer increased after enteral feeding, and a significant difference in the Pco2 of the full versus the empty stomach was evident at 24 and 48 hours. Pco2 at 4, 24, and 48 hours differed significantly in the full stomach and in the empty stomach. However, the data did not reveal a significant difference in either the full stomach or the empty stomach between Pco2 at 24 hours and Pco2 at 48 hours.• Conclusion After 24 hours of feeding, the initial increase in Pco2 observed at 4 hours was not evident, suggesting stabilization of the intragastric environment. However, a higher Pco2 was evident in the empty stomach, indicating that the presence of the feeding solution may reduce the diffusion of carbon dioxide into the tonometer balloon. Consequently, measurements of intragastric Pco2 obtained after 24 hours of feeding may be reliable if the stomach is emptied by aspiration via the tonometer immediately before measurement.
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Affiliation(s)
- Andrea P. Marshall
- Department of Clinical Nursing, Faculty of Nursing, University of Sydney (APM, SHW), and Department of Critical Care, Manly Hospital, Manly, NSW, Australia (APM)
| | - Sandra H. West
- Department of Clinical Nursing, Faculty of Nursing, University of Sydney (APM, SHW), and Department of Critical Care, Manly Hospital, Manly, NSW, Australia (APM)
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Abstract
Controversy exists as to the best means to monitor the critically ill patient and the appropriate end points of therapy. Use of global hemodynamic or metabolic parameters may be normal in the patient who has not been completely or adequately resuscitated. Decreased perfusion to the gut is not well tolerated and may contribute to the development of the multiple organ dysfunction syndrome. Gastric tonometry is a minimally invasive way to monitor splanchnic perfusion in the critically ill patient. Data suggest that tonometry is useful for outcome prognostication and for detection of early hypovolemia. In addition, use of gastric intramucosal pH or mucosal-arterial CO(2) gap as end points of resuscitation may be superior to other conventional whole-body parameters. For these reasons, gastric tonometry must be considered the hemodynamic monitor of choice.
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Affiliation(s)
- Stephen O Heard
- Department of Anesthesiology, University of Massachusetts Medical School, Worcester 01655, USA.
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Boswell SA, Scalea TM. Sublingual capnometry: an alternative to gastric tonometry for the management of shock resuscitation. AACN CLINICAL ISSUES 2003; 14:176-84. [PMID: 12819455 DOI: 10.1097/00044067-200305000-00008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Normal vital signs do not reflect the physiologic aberrations after blood loss. Recognition of hypoperfusion during resuscitation can avoid the development of multiple organ failure. Advances in technology enable the clinician to monitor changes, potentially identifying tissue hypoxia much earlier than previously was possible. Gastric tonometry can be quite helpful in the intensive care unit in identifying gastric hypoperfusion, but has considerable drawbacks. The ability to monitor P(SI)CO(2) via sublingual capnometers overcomes some limitations of gastric tonometry and may be a valuable aid in the prehospital phase, the emergency department, and the intensive care unit in identifying end points of resuscitation.
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Affiliation(s)
- Sharon A Boswell
- R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, Md, USA.
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Janssens U, Groesdonk H, Graf J, Radke PW, Lepper W, Hanrath P. Comparison of oesophageal and gastric air tonometry in patients with circulatory failure. Br J Anaesth 2002; 89:237-41. [PMID: 12378659 DOI: 10.1093/bja/aef174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Gastric PCO2 measured by balloon tonometry can estimate the adequacy of splanchnic perfusion. However, enteral feeding and gastric content can interfere with gastric PCO2 assessment. Tonometry in other sites of the body could avoid these problems. We therefore tested the hypothesis that oesophageal air tonometry would give results similar to gastric tonometry. METHODS We studied 20 consecutive patients (mean age 68 (SD 9) [range 49-81] yr, 18 males, SAPS II score 55 (SD 18), ICU mortality 55%) with circulatory disorders during mechanical ventilation in the intensive care unit. Tonometer probes were placed via the nose, one into the stomach and the other in the oesophagus. PCO2 was measured with two automated gas analysers, at admission and 30 min, 1, 2, 3, 32, 40, and 48 h thereafter. RESULTS One hundred and forty-eight paired measurements were obtained. Gastric PCO2 was greater than oesophageal PCO2 on admission (7.19 (1.43) vs 5.89 (0.73) kPa, P < 0.01) and subsequently. Differences between the measures correlated (r = 0.67) with the mean absolute value, indicating that overestimation increased as gastric PCO2 increased. CONCLUSIONS Oesophageal PCO2 is less than gastric PCO2, and the difference is greater when gastric PCO2 levels are greater. Air tonometry may not measure regional PCO2 levels in the oesophagus satisfactorily. Other methods and sites for carbon dioxide tonometry should be examined.
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Affiliation(s)
- U Janssens
- FESC, Medical Clinic I, University of Aachen, Pauwelsstrasse 30, D-52057 Aachen, Germany
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Hu S, Sheng ZY. The effects of anisodamine and dobutamine on gut mucosal blood flow during gut ischemia/reperfusion. World J Gastroenterol 2002; 8:555-7. [PMID: 12046091 PMCID: PMC4656442 DOI: 10.3748/wjg.v8.i3.555] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine if anisodamine is able to augment mucosal perfusion during gut I/R ischemia-reperfusion.
METHODS: A jejunal sac was formed in Sprague Dawley rat. A Laser Doppler probe and a tonometer were inserted into the sac which was filled with saline. The superior mesenteric artery was occluded (SMAO) for 60 minutes followed by 90 minutes of reperfusion. At the end of 60 minutes of SMAO, either 0.2 mg/kg of anisodmine or dobutamine was injected into the jejunal sac. Laser Doppler mucosal blood flow and regional PCO2 (PrCO2) measurements were made.
RESULTS: Mucosal blood flow was significantly increased at 30, 60 and 90 minutes of reperfusion (R30, R60, R90) when intraluminal anisodamine or dobutamine was present compared to intraluminal saline only (44 ± 3.3% or 48 ± 4.1% vs 37 ± 2.6% at R30, 57 ± 5.0% or 56 ± 4.7% vs 45 ± 2.7% at R60, 64 ± 3.3% or 56 ± 4.2% vs 48 ± 3.4% at R90, respectively P < 0.05). Blood flow changes were also reflected by lowering of jejunal PrCO2 measurements after intraluminal anisodamine or dobutamine compared with that of the saline controls (41 ± 3.1 mmHg or 44 ± 3.0 mmHg vs 49 ± 3.7 mmHg at R30, 38 ± 3.7 mmHg or 40 ± 2.1 mmHg vs 47 ± 3.8 mmHg at R60, 34 ± 2.1 mmHg or 39 ± 3.0 mmHg vs 46 ± 3.4 mmHg at R90, respectively, P < 0.05). Most interesting finding was that there were significantly higher mucosal blood flow and lower jejunal PrCO2 in anisodamine group than those in dobutamine group at 90 minutes of reperfusion (64 ± 3.3% vs 56 ± 4.2% for blood flow or 34 ± 2.1 mmHg vs 39 ± 3.0 mmHg for PrCO2, respectively, P < 0.05), suggesting that anisodamine had a more lasting effect on mucosal perfusion than dobutamine.
CONCLUSION: Intraluminal anisodamine and dobutamine can augment mucosal blood flow during gut I/R and alleviate mucosal acidosis. The results provided benificial effects on the treatment of splanchnic hypoperfusion following traumatic or burn shock.
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Affiliation(s)
- Sen Hu
- Burns Institute, 304th Hospital of PLA, 51 Fu Cheng Road, Beijing 100037, China
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Kutschma J, Andel H. The development of the gastric CO2 gap in the first 48 hours after severe burn injury. THE JOURNAL OF TRAUMA 2002; 52:1012; author reply 1012-3. [PMID: 11988678 DOI: 10.1097/00005373-200205000-00037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
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MacLaren R, Jarvis CL, Fish DN. Use of enteral nutrition for stress ulcer prophylaxis. Ann Pharmacother 2001; 35:1614-23. [PMID: 11793631 DOI: 10.1345/aph.1a083] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE To review the controversies involving the use of enteral nutrition support for stress ulcer prophylaxis and formulate recommendations. DATA SOURCES A MEDLINE search (1966-December 2000) was conducted using the MeSH of nutrition, ulcer, critical care, and acid to identify relevant articles. References of selected articles were reviewed, and relevant abstracts from critical care or gastrointestinal journals identified. DATA EXTRACTION Animal and human data from prospective studies, retrospective studies, and case series were evaluated for the effects of enteral nutrition on gastric pH, intramucosal pH, gastrointestinal blood flow, development of macroscopic mucosal erosions, and hemorrhage. DATA SYNTHESIS Intragastric administration of enteral nutrition has variable effects on gastric pH, enhances regional distribution of gastrointestinal blood flow, and may lower intramucosal pH. All substrates (carbohydrate, lipid, amino acid), when administered into the stomach, reduce the occurrence of mucosal erosions but do not entirely prevent their development. Few studies of stress ulcer prophylaxis regimens have reported use of enteral nutrition. Limited retrospective data suggest enteral nutrition support may be effective for preventing gastrointestinal hemorrhage, but the results of prospective studies are confounded by poor study design. CONCLUSIONS Definitive recommendations regarding the role of enteral nutrition for stress ulcer prophylaxis are not possible due to the lack of prospective, randomized studies. Therefore, the use of enteral nutrition as the only therapeutic agent for stress ulcer prophylaxis should be discouraged until definitive data are available. Initiation and discontinuation of pharmacologic stress ulcer prophylaxis should be independent of enteral nutrition.
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Affiliation(s)
- R MacLaren
- School of Pharmacy, C238, University of Colorado Health Sciences Center, 4200 E. Ninth Ave., Denver, CO 80262-0001, USA.
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Abstract
OBJECTIVE To compare sublingual PCO(2) (PslCO(2)) measurements with gastric intramucosal PCO(2) (PimCO(2)) as well as with the traditional indexes of tissue oxygenation in hemodynamically unstable ICU patients. DESIGN A prospective, validation study. SETTING The medical and coronary ICUs of a community teaching hospital. PATIENTS Consecutive patients with severe sepsis, septic shock, or cardiogenic shock requiring pulmonary artery catheterization for hemodynamic management. INTERVENTIONS During the first 24 h of ICU admission, the PslCO(2), PimCO(2), and blood lactate concentrations as well conventional hemodynamic and oxygenation parameters were recorded every 4 to 6 h. The PslCO(2)-PaCO(2) and PimCO(2)-PaCO(2) differences were used as indexes of tissue dysoxia. These variables were correlated with each other as well as with the traditional markers of tissue oxygenation. RESULTS Seventy-six data sets were obtained on 22 patients. Fifteen patients had severe sepsis/septic shock, and 7 patients did not have sepsis. A patient with ischemic bowel who had a large PimCO(2)-PslCO(2) difference (60.2 mm Hg) was excluded. The initial PslCO(2) and PimCO(2) measurements were 43.5 +/- 10.4 mm Hg and 42.8 +/- 10.9 mm Hg, respectively (correlation coefficient [r] of 0.86; p < 0.001). The mean PslCO(2) and PimCO(2) for the entire data set were 48.0 +/- 13.4 mm Hg and 46.1 +/- 12.3 mm Hg, respectively (r = 0.78; p < 0.001). Ten patients died. The initial PslCO(2)-PaCO(2) difference was 9.2 +/- 5.0 mm Hg in the survivors and 17.8 +/- 11.5 mm Hg in the nonsurvivors (p = 0.04). The initial PimCO(2)-PaCO(2) difference was 8.4 +/- 4.8 mm Hg in the survivors and 16.1 +/- 13.7 mm Hg in the nonsurvivors (p = 0.08, not significant). The initial PslCO(2)-PaCO(2) difference correlated with the initial mixed venous-arterial CO(2) gradient (r = 0.66; p = 0.001), but correlated poorly with the initial blood lactate concentration (r = 0.38), mixed venous PO(2) (r = 0.05), and systemic oxygen delivery (r = - 0.39). CONCLUSION In this study, sublingual capnometry yielded measurements that correlated well with those of gastric tonometry. PslCO(2) may serve as a technically simple and noninvasive clinical measurement of tissue dysoxia in critically ill and injured patients.
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Affiliation(s)
- P E Marik
- Critical Care Medicine, The Mercy Hospital of Pittsburgh, Pittsburgh, PA 15219-5166, USA.
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Rokyta R, Novák I, Matĕjovic M, Hora P, Nalos M, Srámek V. Impact of enteral feeding on gastric tonometry in healthy volunteers and critically ill patients. Acta Anaesthesiol Scand 2001; 45:564-9. [PMID: 11309005 DOI: 10.1034/j.1399-6576.2001.045005564.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Enteral feeding may interfere with gastric tonometry measurement. The effect of enteral nutrition on gastric tonometry has not been fully documented. METHODS Seven healthy volunteers and nine stable intensive care unit (ICU) patients with poor tolerance of gastric feeding were investigated. Consecutive continuous postpyloric and gastric feeding, both at two different rates (40 and 100 ml. h-1, respectively), and an intragastric 200 ml nutrition bolus were studied. Gastric intramucosal PCO2 (PiCO2) was measured by air tonometry and in patients a gastric intramucosal-arterial PCO2 difference (PCO2 gap) was calculated. Hemodynamics and blood gases were also measured. RESULTS In volunteers, PiCO2 remained stable during the postpyloric phase. During continuous gastric feeding PiCO2 did not change significantly, although in 4 volunteers PiCO2 increased >0.5 kPa. PiCO2 decreased significantly after gastric bolus from 6.9+/-0.4 to 6.1+/-0.5 kPa (P<0.05). Eight patients had an increased PCO2 gap (>1 kPa) at baseline (1.8+/-0.6 kPa). PCO2 gap changes during the whole study were not statistically significant. However, during the postpyloric phase (or immediately afterwards), the PCO2 gap increased by more than 0.5 kPa in 5 patients. After gastric bolus, a decrease in PCO2 gap >0.5 kPa was seen in 5 patients. CONCLUSION In volunteers, postpyloric feeding does not interfere with gastric tonometry measurement and gastric bolus leads to a PiCO2 decrease. The impact of postpyloric and gastric feeding on gastric tonometry in ICU patients with compromised gut is variable.
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Affiliation(s)
- R Rokyta
- Intensive Care Unit, Medical Department I, Charles University Hospital Plzen, Alej Svobody 80, 304 60 Plzen, Czech Republic.
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Venkatesh B, Meacher R, Muller MJ, Morgan TJ, Fraser J. Monitoring tissue oxygenation during resuscitation of major burns. THE JOURNAL OF TRAUMA 2001; 50:485-94. [PMID: 11265028 DOI: 10.1097/00005373-200103000-00013] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Because subcutaneous and splanchnic oxygenation indices are sensitive indicators of evolving hemorrhagic shock and adequacy of resuscitation, we postulated that these indices might have an equivalent role in the monitoring of severely burned patients. This observational study was undertaken to examine changes in tissue oxygenation indices during burn resuscitation. METHODS Seven patients with major burns (54 +/- 21% total body surface area) were studied during the first 36 hours of fluid resuscitation. Silastic tubing was placed in the subcutaneous tissue just beneath both normal skin and deep partial thickness burn. Fiberoptic sensors inserted into the tubing measured subcutaneous oxygen and carbon dioxide tensions in the burnt skin (PO2scb and PCO2scb) and normal skin (PO2scn and PCO2scn) continuously. Gastric intramucosal pH (pHi) and the mucosal CO2 (PCO2m) gap were calculated using gastric tonometers. Mean arterial pressure, arterial pH, lactate, and pHi measurements were obtained for 36 hours. RESULTS There were no significant differences in mean arterial pressure, arterial pH, or lactate concentrations throughout the study period, whereas indices of tissue oxygenation showed deterioration: pHi decreased from 7.2 +/- 0.1 to 6.7 +/- 0.3 (p = 0.06), the PCO2m gap increased from 12 +/- 17 to 108 +/- 123 mm Hg (p < 0.01), PO2scn decreased from 112 +/- 18 to 50 +/- 11 mm Hg (p < 0.01), PO2scb decreased from 62 +/- 23 to 29 +/- 16 mm Hg (p < 0.01), PCO2scn increased from 42 +/- 4 to 46 +/- 10 mm Hg (p = 0.2), and PCO2scb increased from 42 +/- 10 to 52 +/- 5 mm Hg (p = 0.05). CONCLUSION Despite adequate global indices of tissue perfusion after 36 hours of resuscitation, tissue monitoring indicated significant deterioration in the splanchnic circulation and in the normal and burnt skin.
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Affiliation(s)
- B Venkatesh
- University of Queensland, Herston, Queensland, Australia.
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MacLaren R. Intolerance to intragastric enteral nutrition in critically ill patients: complications and management. Pharmacotherapy 2000; 20:1486-98. [PMID: 11130221 DOI: 10.1592/phco.20.19.1486.34853] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Compared with parenteral nutrition, early administration of enteral nutrition (EN) to critically ill patients improves clinical outcomes and reduces infection rates. Intragastric EN often is complicated by intolerance, as indicated by elevated volumes of aspirated gastric residuals. Conflicting data are available for the volume of residual that represents intolerance, but most clinicians use 150-200 ml to signify gastrointestinal motility dysfunction. Intolerance is associated with mortality. Data support an association between intragastric EN and aspiration pneumonia, but little information is available regarding the contributory effect of intolerance. Transpyloric migration of the feeding tube may facilitate tolerance but does not reduce the likelihood of aspiration pneumonia. Prokinetic agents (cisapride, erythromycin, metoclopramide) promote gastric emptying. Results of most studies are limited because patients did not receive or tolerated intragastric EN. Metoclopramide is the agent of choice for treating intolerance. Further studies are necessary before prokinetic drugs can be recommended for preventing intragastric EN-associated aspiration pneumonia.
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Affiliation(s)
- R MacLaren
- School of Pharmacy, University of Colorado Health Sciences Center, Denver 80262, USA
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Koivusalo A, Kauppinen H, Anttila A, Heikkilä P, Rintala R, Lindahl H. Rectosigmoid pHi monitoring during experimental necrotizing enterocolitis. J Pediatr Surg 2000; 35:1462-7. [PMID: 11051152 DOI: 10.1053/jpsu.2000.16415] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND/PURPOSE Gastric or rectosigmoid intramural pH (pHi) is considered a reliable indicator of splanchnic perfusion. The aim of this study was to evaluate whether rectosigmoid pHi reflects the severity of bowel damage in experimental necrotizing enterocolitis (NEC). METHODS A total of 36 neonatal piglets, (median age, 3; range, 1 to 11 days; median weight, 2.5; range, 1.2 to 3.8 kg), were anesthetized, ventilated mechanically, and had invasive monitoring of hemodynamics. A sigmoid tonometer was inserted into the rectosigmoid colon. Enterocolitis was induced in 27 piglets by intraluminal injection of casein-d-gluconate (16.0 mL/kg) into terminal 100 cm of the ileum. Nine control piglets received an equal amount of intraluminal saline. NEC was graded macroscopically as follows: 0, no changes; 1, mild; 2, moderate; and 3, severe. Histology was evaluated according to Chiu scale from 0 to 5. RESULTS The macroscopical bowel injury in caseine-injected piglets was as follows: grade 3 (n = 6), grade 2 (n = 9), grade 1 (n = 12). All control piglets showed macroscopically normal bowel (grade 0). All affected bowels showed histologic changes (Chiu's scale 2 to 4). All study animals had an initial drop of pHi after injection of casein or saline. In control piglets and those with mild NEC (grade 1) pHi tended to return to preinjection level. In animals with moderate or severe NEC (grade 2 to 3) the initial drop was deeper and the pHi continued to decrease significantly throughout the experiment (P < .05). In the arterial pH and mean blood pressure there were no statistically significant differences between piglets with no NEC and mild NEC, and these with moderate or severe NEC. CONCLUSION Drop in rectosigmoid pHi was the most sensitive and earliest sign of severe mucosal necrosis of ileum in this experimental NEC model.
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Affiliation(s)
- A Koivusalo
- Helsinki University Hospital for Children and Adolescents, Finland
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Venkatesh B, Townsend S, Boots RJ. Does splanchnic ischemia occur in isolated neurotrauma? A prospective observational study. Crit Care Med 1999; 27:1175-80. [PMID: 10397225 DOI: 10.1097/00003246-199906000-00047] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To characterize the incidence and severity of splanchnic ischemia, as defined by gastric tonometry, in patients with isolated severe head injury and to examine the relationship between cerebral hemodynamics and splanchnic ischemia. DESIGN Prospective observational study. SETTING Neurosurgical intensive care unit in a tertiary referral center. PATIENTS Ten patients with severe neurotrauma. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS The mean arterial pressure, intracranial pressure, and gastric mucosal P(CO2) measurements were recorded at 15-min intervals. Intramucosal pH was calculated every 3 hrs. All patients received stress ulcer prophylaxis. Nine patients received noradrenaline infusions to maintain a target cerebral perfusion pressure of 70 mm Hg. The mean baseline gastric mucosal P(CO2) and intramucosal pH were 38+/-10 torr and 7.38+/-0.1 pH units, respectively. Nine patients manifested low intramucosal pH during the study period. Gastric mucosal P(CO2) values ranged from 36 to 132 torr. Intramucosal pH measurements ranged from 6.9 to 7.47. The mucosal gap ranged from -12 to +93 torr (mean +/- SD, 17+/-17 torr). The pH gap ranged from -0.1 to +0.54 pH units (mean +/- SD, 0.14+/-0.11 pH units). There was no statistically significant relationship between cerebral hemodynamics, the use of inotropes, and gastric mucosal P(CO2), or intramucosal pH. CONCLUSIONS Splanchnic ischemia (intramucosal pH, <7.3) occurs commonly in isolated neurotrauma, with a statistically nonsignificant trend toward development of mucosal ischemia with decreased cerebral perfusion.
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Affiliation(s)
- B Venkatesh
- Royal Brisbane Hospital, University of Queensland, Herston, Australia
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Ala-Kokko TI, Laurila J. Continuous gastric mucosal capnometry is affected by enteral nutrition: potential for misinterpretation of tissue oxygenation. Chest 1999; 115:1482-3. [PMID: 10334185 DOI: 10.1378/chest.115.5.1482-a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Kolkman JJ, Groeneveld AB, Meuwissen SG. Effect of gastric feeding on intragastric P(CO2) tonometry in healthy volunteers. J Crit Care 1999; 14:34-8. [PMID: 10102722 DOI: 10.1016/s0883-9441(99)90006-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The tonometric detection of a high intragastric regional P(CO2) (PrCO2) reflecting an elevated intramucosal P(CO2) can be helpful to diagnose mucosal ischemia, if acid secretion is suppressed to avoid intragastric CO2 production through buffering of acid by bicarbonate in the stomach. It is recommended to perform tonometry in the fasting state, but this may hamper feeding of the critically ill. On the other hand, postfeeding tonometry could serve as a diagnostic stress test because feeding increases mucosal blood flow demand, provided that the meal itself does not hamper diffusion of CO2 from mucosa to tonometer balloon and does not generate intragastric CO2, independently from intramucosal P(CO2). We therefore studied the effect of a standard meal on intragastric PrCO2 tonometry in healthy volunteers with suppression of meal-stimulated gastric acid secretion and, presumably, with an adequate mucosal blood flow reserve. MATERIAL AND METHODS The gastric juice pH and tonometric PrCO2 were measured in 14 human volunteers, after gastric acid secretion suppression by either ranitidine (100-mg bolus, followed by 25 mg/h i.v., n = 7) or by ranitidine plus pirenzepine (10-mg bolus, followed by 3 mg/h i.v., n=7) to suppress any residual meal-stimulated gastric acid secretion, before and at 30-minute intervals until 120 minutes after oral ingestion of a standard liquid test meal (Pulmocare [Abbott, the Netherlands]; 500 mL, 750 kcal, P(CO2) 5 mm Hg, pH 7.50). RESULTS The gastric juice pH, which was >4.0 in all individuals throughout the study, and the PrCO2 did not depend on the regimen for gastric acid secretion suppression, and therefore the data were pooled. The PrCO2 (median [range]) after feeding was 69% (56% to 170%) of baseline (42 [37-51] mm Hg) from 0 to 30 minutes (P < .001), 85% (72% to 167%) of baseline from 30 to 60 (P < .05), 97% (57% to 193%) from 60 to 90 minutes, and 112% (97% to 189%) of baseline from 90 to 120 minutes with a rise above baseline in 10 of 14 patients. In vitro, the liquid test meal generated CO2 after adding bicarbonate but not after hydrochloric acid. CONCLUSION We recommend intragastric tonometry to be performed in the fasting state and discourage tonometry after feeding as a stress test, because a single test meal changes tonometric PrCO2 in a time-dependent manner until 2 hours after gastric feeding of healthy volunteers. The fall in PrCO2 directly after feeding can be attributed to dilution, whereas a rise above baseline in some patients may have been caused, as supported by CO2 production after adding bicarbonate to the test meal in vitro, by CO2 production through buffering of meal-derived acid by gastric bicarbonate, in the absence of stimulated gastric acid secretion by feeding.
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Affiliation(s)
- J J Kolkman
- Department of Gastroenterology, Medisch Spectrum Twente, Enschede, The Netherlands
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Levy B, Perrigault PF, Gawalkiewicz P, Sebire F, Escriva M, Colson P, Wahl D, Frederic M, Bollaert PE, Larcan A. Gastric versus duodenal feeding and gastric tonometric measurements. Crit Care Med 1998; 26:1991-4. [PMID: 9875909 DOI: 10.1097/00003246-199812000-00026] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE To compare the influence of gastric and postpyloric enteral feeding on the gastric tonometric PCO2 gap (tonometric PCO2 - PaCO2). DESIGN A prospective, clinical trial. SETTING Two intensive care units in a university hospital. PATIENTS Twenty patients undergoing mechanical ventilation and enteral feeding without catecholamines, sepsis, or sign of hypoxia. INTERVENTIONS Patients were randomized to receive feeding through the tonometer (gastric group), or through a postpyloric tube (postpyloric group). MEASUREMENTS AND MAIN RESULTS The patients received tube feeding at a rate of 50 mL/hr during 4 hrs. Baseline measurements included: mean arterial pressure, heart rate, tonometric parameters, arterial gases, and arterial lactate concentration. Except for lactate concentration, these measurements were repeated after 1 and 4 hrs of enteral feeding and 2 hrs after stopping enteral feeding. During the study, arterial pH and PaCO2 did not change. During enteral feeding, the PCO2 gap increased in the gastric group from a mean of 7+/-5 to 17+/-14 (SD) torr (0.9 0.7 to 2.3+/-1.9 kPa) (p< .O01) and did not change in the postpyloric group (5+/-5 to 3+/-1 torr [0.7+/-0.7 to 0.4+/-0.1 kPa]). Two hours after stopping enteral feeding, the PCO2 gap was still increased in the gastric group (15+/-9 vs. 7+/-5 torr [2.0+/-1.2 vs. 0.9+/-0.7 kPa]) (p < .01). CONCLUSION The results indicate that gastric enteral feeding increased the PCO2 gap. However, postpyloric enteral feeding does not interact with gastric tonometric measurements and should be used when using gastric tonometry in enterally fed patients.
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Affiliation(s)
- B Levy
- Polyvalent Intensive Care Unit, Central Hospital, Nancy, France.
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Brinkmann A, Calzia E, Träger K, Radermacher P. Monitoring the hepato-splanchnic region in the critically ill patient. Measurement techniques and clinical relevance. Intensive Care Med 1998; 24:542-56. [PMID: 9681775 DOI: 10.1007/s001340050614] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- A Brinkmann
- Sektion Spezielle Anästhesiologie, Universitätsklinik für Anästhesiologie, Klinikum der Universität Ulm, Germany
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Arévalo JM, Lorente JA, Esteban A. The balance between oxygen supply and demand in the intestine can be assessed by measuring the difference between arterial and intramucosal PCO2 (P[t-a]CO2), estimated by means of a gastric tonometer. THE JOURNAL OF TRAUMA 1998; 44:569. [PMID: 9529197 DOI: 10.1097/00005373-199803000-00033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Abstract
OBJECTIVES To investigate the prognostic value of intramucosal pH (pHi) and the relation among pHi, arterial pH, base excess, and lactate in children with septic shock. DESIGN Children admitted to the paediatric intensive care unit with a diagnosis of septic shock were prospectively enrolled. A gastrointestinal tonometer (Tonometrics Division, Instrumentarium Corporation, Helsinki, Finland) was placed into the stomach and intramucosal pH, arterial pH, base deficit, and lactate were measured on admission and six hours later. Sequential data were analysed on 24 patients (17 survivors, seven non-survivors), median age 46 months (range: 2.8-168 months). RESULTS Median pHi on admission was 7.39 (interquartile range 7.36-7.51) in survivors compared with 7.2 (interquartile range 7.18-7.35) in non-survivors (p = 0.01). There was no significant difference in arterial pH, base excess, or lactate among survivors and non-survivors. Admission pHi < 7.32 predicted mortality with sensitivity (57%), specificity (94%), and positive predictive value (80%). Patients with admission pHi < 7.32 who failed to improve > or = 7.32 within six hours (n = 3) had 100% mortality. CONCLUSION In children with septic shock the admission pHi is significantly lower in non-survivors. pHi is a better prognostic indicator of mortality than either standard acid-base values or lactate. pHi < 7.32 that does not improve within six hours is associated with a poor prognosis.
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Affiliation(s)
- M Hatherill
- Paediatric Intensive Care Unit, Guy's Hospital, London
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39
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Levy B, Bollaert PE, Lucchelli JP, Sadoune LO, Nace L, Larcan A. Dobutamine improves the adequacy of gastric mucosal perfusion in epinephrine-treated septic shock. Crit Care Med 1997; 25:1649-54. [PMID: 9377878 DOI: 10.1097/00003246-199710000-00013] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To assess the effects of dobutamine at a rate of 5 micrograms/kg/min on hemodynamics and gastric intramucosal acidosis in patients with hyperdynamic septic shock treated with epinephrine. DESIGN A prospective, interventional, clinical trial. SETTING An adult, 16-bed medical/surgical intensive care unit of a university hospital. PATIENTS Twenty septic shock patients with a mean arterial pressure of > 75 mm Hg and a cardiac index of > 3.5 L/min/m2. INTERVENTIONS After baseline measurements (H0), each patient received dobutamine at a rate of 5 micrograms/kg/min. Baseline measurements included: hemodynamic parameters, tonometric parameters, arterial and mixed venous gases, and arterial lactate concentrations. These measurements were repeated after 1 (H1), 2 (H2), and 3 (H3) hrs. After H2 measurements, dobutamine was stopped. The patients were separated into two groups according to their PCO2 gap (tonometer PCO2-PaCO2). The increased PCO2 gap group was defined by a PCO2 gap > 8 torr (> 1.1 kPa) (n = 13), and the normal PCO2 gap group by a PCO2 gap < or = 8 torr (< or = 1.1 kPa)(n = 7). MEASUREMENTS AND MAIN RESULTS Dobutamine at 5 micrograms/kg/min had no significant effects on mean arterial pressure, heart rate, cardiac index, systemic vascular resistance, oxygen delivery, and oxygen consumption in epinephrine-treated septic shock. No patients developed arrhythmia or electrocardiographic signs of myocardial ischemia. During dobutamine infusion, arterial lactate concentration decreased from 5.1 +/- 0.4 in the increased PCO2 gap group and 4.2 +/- 0.4 in the normal PCO2 gap group to 3.9 +/- 0.3 and 3.5 +/- 0.3 mmol/L, respectively (p < .01). The PCO2 gap decreased and gastric intramucosal pH increased in the increased PCO2 gap group from 12 +/- 0.8 (1.6 +/- 0.1 kPa) to 3.5 +/- 0.8 torr (0.5 +/- 0.1 kPa) (p < .01) and from 7.11 +/- 0.03 to 7.18 +/- 0.02 (p < .01), respectively, and did not change in the normal PCO2 gap group. After stopping dobutamine infusion, the PCO2 gap and intramucosal pH returned to baseline values in the increased PCO2 gap group. CONCLUSION The addition of 5 micrograms/kg/min of dobutamine added to epinephrine in hyperdynamic septic shock selectively improved the adequacy of gastric mucosal perfusion without modification in systemic hemodynamics.
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Affiliation(s)
- B Levy
- Medical Intensive Care Unit, Central Hospital, Nancy, France
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40
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Baigorri F, Calvet X, Joseph D. Gastric intramucosal pH measurement. Crit Care 1997; 1:61-64. [PMID: 11094465 PMCID: PMC137220 DOI: 10.1186/cc104] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/1997] [Indexed: 01/16/2023] Open
Affiliation(s)
- Francisco Baigorri
- Intensive Care Service, Hospital de Sabadell, Parc Tauli s/n, 08208 Sabadell, Spain
| | - Xavier Calvet
- Intensive Care Service, Hospital de Sabadell, Parc Tauli s/n, 08208 Sabadell, Spain
| | - Domenec Joseph
- Intensive Care Service, Hospital de Sabadell, Parc Tauli s/n, 08208 Sabadell, Spain
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41
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Abstract
Gastrointestinal tonometry is supposed to diagnose gut mucosal hypoxia using gastric luminal PCO2 and arterial bicarbonatemia, which are substituted in a modified Henderson-Hasselbach equation. This article reviews some of the problems inherent to the multiple assumptions underlying this technique. Tonometry is influenced by several local factors and by systemic acid-base imbalances that are unrelated to oxygenation. Tonometry is a rather crude and cumbersome method of gut capnometry, a technology that may provide valuable information regarding visceral perfusion, but not necessarily oxygenation.
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Affiliation(s)
- E Benjamin
- Department of Surgery, Mount Sinai Medical Center, City University of New York, New York, USA
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