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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Screening av dysfagi på äldreboenden i Linköpings kommun / Screening of Dysphagia in Nursing Homes in the Municipality of Linköping

Helldén, Josefin, Sjölund, Ellinor January 2009 (has links)
<p>Changes in swallowing function are common in elderly and chronically ill individuals. Therefore it is important to be aware of these changes and their prevalence. The aim of this study was to assess the prevalence of dysphagia in nursing homes in the municipality of Linköping, and to correlate dysphagia with variables that can be a cause or a consequence of dysphagia. These variables were gender, age, MMT-result, dentition, weight loss, medical diagnose or number of medications. The intention was also to examine the additional information regarding dysphagia supplied by pulse oximetry.</p><p>Sixty nursing home residents aged 74-101 years were chosen to participate in the study. The individual's ability to participate was based on their result on Mini-mental state and subjective judgements made by staff members and the authors. The material to assess oral motor and sensory function was the Nordic Orofacial Test - Screening. During the clinical swallowing examination the Standardised Swallowing Assessment (SSA) and pulse oximetry were used. In addition, data regarding the participants' medical diagnoses, number of medications and possible weight loss was collected.</p><p>The result showed that the prevalence of dysphagia and suspected dysphagia was 40 %. Oral dysphagia was present in 20 participants and pharyngeal dysphagia in seven participants. With pulse oximetry one participant with dysphagia and two with suspected dysphagia were identified in addition to those identified by SSA. Analysis of the assessed variables showed no correlations or any significant results.</p> / <p>Förändringar av sväljförmågan är vanligt hos äldre och kroniskt sjuka individer. Det är viktigt att vara medveten om dessa förändringar och hur vanligt förekommande det är med nedsatt sväljförmåga. Syftet med föreliggande studie var att undersöka förekomsten av dysfagi på äldreboenden i Linköpings kommun samt att korrelera dysfagi med parametrar som kan vara orsak till eller konsekvens av dysfagi. Dessa parametrar var kön, ålder, MMT-resultat, tandstatus, viktnedgång, sjukdomsdiagnos och antal läkemedel. Ett delsyfte i studien var att undersöka om man med hjälp av pulsoximetri kan upptäcka fler fall av dysfagi.</p><p>Sextio vårdtagare på äldreboenden, i åldern 74-101 år, valdes ut att delta i studien. Urvalet baserades på resultat på Mini-Mental Test samt personalens och testledarnas subjektiva bedömning om vårdtagarens möjlighet att delta. Materialet som användes för att bedöma oral motorik och sensorik var Nordiskt Orofacialt Test – Screening. Vid den kliniska sväljningsbedömningen användes Standardised Swallowing Assessment (SSA) och pulsoximetri. Utöver detta inhämtades uppgifter för samtliga deltagare om sjukdomsdiagnos, antal stående läkemedel samt eventuell viktnedgång.</p><p>Resultatet visade att förekomsten av dysfagi och misstänkt dysfagi var 40 %. Oral dysfagi förekom hos 20 deltagare och faryngeal dysfagi hos sju deltagare. Pulsoximetern identifierade en deltagare med dysfagi och två med misstänkt dysfagi utöver dem som identifierats med hjälp av SSA. Korrelations- och signifikansberäkningar av de undersökta parametrarna visade inga signifikanta resultat.</p>
22

Screening av dysfagi på äldreboenden i Linköpings kommun / Screening of Dysphagia in Nursing Homes in the Municipality of Linköping

Helldén, Josefin, Sjölund, Ellinor January 2009 (has links)
Changes in swallowing function are common in elderly and chronically ill individuals. Therefore it is important to be aware of these changes and their prevalence. The aim of this study was to assess the prevalence of dysphagia in nursing homes in the municipality of Linköping, and to correlate dysphagia with variables that can be a cause or a consequence of dysphagia. These variables were gender, age, MMT-result, dentition, weight loss, medical diagnose or number of medications. The intention was also to examine the additional information regarding dysphagia supplied by pulse oximetry. Sixty nursing home residents aged 74-101 years were chosen to participate in the study. The individual's ability to participate was based on their result on Mini-mental state and subjective judgements made by staff members and the authors. The material to assess oral motor and sensory function was the Nordic Orofacial Test - Screening. During the clinical swallowing examination the Standardised Swallowing Assessment (SSA) and pulse oximetry were used. In addition, data regarding the participants' medical diagnoses, number of medications and possible weight loss was collected. The result showed that the prevalence of dysphagia and suspected dysphagia was 40 %. Oral dysphagia was present in 20 participants and pharyngeal dysphagia in seven participants. With pulse oximetry one participant with dysphagia and two with suspected dysphagia were identified in addition to those identified by SSA. Analysis of the assessed variables showed no correlations or any significant results. / Förändringar av sväljförmågan är vanligt hos äldre och kroniskt sjuka individer. Det är viktigt att vara medveten om dessa förändringar och hur vanligt förekommande det är med nedsatt sväljförmåga. Syftet med föreliggande studie var att undersöka förekomsten av dysfagi på äldreboenden i Linköpings kommun samt att korrelera dysfagi med parametrar som kan vara orsak till eller konsekvens av dysfagi. Dessa parametrar var kön, ålder, MMT-resultat, tandstatus, viktnedgång, sjukdomsdiagnos och antal läkemedel. Ett delsyfte i studien var att undersöka om man med hjälp av pulsoximetri kan upptäcka fler fall av dysfagi. Sextio vårdtagare på äldreboenden, i åldern 74-101 år, valdes ut att delta i studien. Urvalet baserades på resultat på Mini-Mental Test samt personalens och testledarnas subjektiva bedömning om vårdtagarens möjlighet att delta. Materialet som användes för att bedöma oral motorik och sensorik var Nordiskt Orofacialt Test – Screening. Vid den kliniska sväljningsbedömningen användes Standardised Swallowing Assessment (SSA) och pulsoximetri. Utöver detta inhämtades uppgifter för samtliga deltagare om sjukdomsdiagnos, antal stående läkemedel samt eventuell viktnedgång. Resultatet visade att förekomsten av dysfagi och misstänkt dysfagi var 40 %. Oral dysfagi förekom hos 20 deltagare och faryngeal dysfagi hos sju deltagare. Pulsoximetern identifierade en deltagare med dysfagi och två med misstänkt dysfagi utöver dem som identifierats med hjälp av SSA. Korrelations- och signifikansberäkningar av de undersökta parametrarna visade inga signifikanta resultat.
23

Διάγνωση της υποξίας κατά τη διάρκεια του τοκετού βασιζόμενη στην ανάλυση του εμβρυικού καρδιακού ρυθμού και της παλμικής οξυμετρίας

Σηφάκης, Εμμανουήλ 19 December 2008 (has links)
Στόχος της παρούσας εργασίας αποτελεί η έγκαιρη πρόβλεψη οξυαιμίας βασιζόμενη στην ανάλυση των πολύ χαμηλής συχνότητας συστατικών του εμβρυϊκού καρδιακού ρυθμού και των καταγραφών της εμβρυϊκής παλμικής οξυμετρίας (FSpO2) κατά τη διάρκεια του τοκετού. Για τη φασματική ανάλυση έγινε εφαρμογή του συνεχούς μετασχηματισμού κυματιδίων (CWT). Για την ανάλυση των καταγραφών του FSpO2 υπολογίστηκε το ποσοστό του συνολικού χρόνου όπου ο FSpO2 είναι κάτω του ορίου 30% (TFSpO2<30%). Όπως αποδείχθηκε τόσο από την εφαρμογή του CWT, όσο και από την παράμετρο TFSpO2<30%, οι κυματισμοί του εμβρυϊκού καρδιακού ρυθμού στην περιοχή συχνοτήτων του 0.01 Hz, παρουσιάζουν ικανοποιητική ευαισθησία (80% and 90%, αντίστοιχα) για την έγκαιρη πρόβλεψη οξυαιμίας, ενώ ο συνδυασμός τους παρουσιάζει υψηλή προσδιοριστικότητα (89%). Τα αποτελέσματα της ανάλυσης των δεδομένων όπως προκύπτουν από την ανάλυση του εμβρυϊκού καρδιακού ρυθμού – μέσω εφαρμογής του CWT – και των καταγραφών της εμβρυϊκής παλμικής οξυμετρίας δύναται να αποτελέσουν μια επιπρόσθετη πηγή πληροφορίας όσον αφορά την κατάσταση του εμβρύου βοηθώντας ταυτοχρόνως τον γυναικολόγο στην απόφαση για το χρόνο και τον τρόπο διεξαγωγής του τοκετού. / The objective of the present study is the prediction of fetal acidemia based on the Very Low Frequency (VLF) components of the Fetal Heart Rate (FHR) and Fetal Pulse Oximetry (FSpO2) recordings during labor. In order to perform the spectral analysis, we applied the Continuous Wavelet Transform (CWT). The evaluation of FSpO2 was based on calculating the time duration in which the FSpO2 was less than 30% (TFSpO2<30%). We demonstrate that the oscillating activity of the FHR of about 0.01 Hz identified by the CWT and the TFSpO2<30% parameter, show an adequate sensitivity (80% and 90%, respectively) in predicting fetal acidemia, whereas the combination of these two variables shows a very good specificity (89%). The results of the analysis of our data demonstrate that the analysis of the fetal heart rate by the CWT and the fetal pulse oximetry recordings may provide additional source of information about fetal status and to alert the clinician to decide under objective conditions when and how to perform the delivery.
24

ISSUES IMPACTING CONTINUOUS PULSE OXIMETRY MONITORING AND WIRELESS CLINICIAN NOTIFICATION SYSTEM AFTER SURGERY / EVALUATION OF ISSUES IMPACTING WIRELESS CLINICIAN NOTIFICATION SYSTEM IN A RANDOMIZED CONTROL TRIAL INVOLVING POSTOPERATIVE VITAL SIGNS MONITORING AND CONTINUOUS PULSE OXIMETRY

Harsha, Prathiba January 2019 (has links)
Background: The VItal siGns monItoring with continuous puLse oximetry And wireless cliNiCian notification aftEr surgery (VIGILANCE) study was a randomized controlled trial designed to assess the impact of continuous vital sign monitoring with alerts to nursing staff on the incidence of postoperative complications in surgical ward patients. Multiple factors interfered with the eHealth intervention implementation and conduct of the VIGILANCE study. Through examination of these challenges, the overall aim of this thesis was to help foster an understanding of the difficulties related to eHealth intervention implementation. The specific objectives were to identify issues related to implementation of intervention system of the VIGILANCE study, and to evaluate the influence of these issues on intervention adoption. Methods: During the VIGILANCE study, issues affecting the implementation of the intervention were documented on case report forms, alarm event forms, and a nursing feedback questionnaire. In this thesis, the issues were identified and evaluated using the Clinical Adoption Framework. Results: The key issues identified include nursing workflow changes, patient withdrawal, wireless network connectivity, false alarms, monitor malfunction, probe issues, and wireless network standards. These issues affected the service, system and information quality. As a result, these issues impacted ‘access’ through decreased ability of nurses to make complete use of the monitors; ‘care quality’ of the trial intervention through decreased effectiveness; and ‘productivity’ through interference in the coordination of care, and thus decreased clinical adoption of the monitoring system. Conclusion: Patient monitoring with eHealth technology in surgical wards has the potential to improve patient outcomes. However, proper planning that includes engagement of front-line nurses, installation of appropriate wireless network infrastructure, and use of comfortable cableless devices are required to maximize the potential of continuous monitoring. / Thesis / Master of Science (MSc) / The VIGILANCE study was a randomized controlled trial assessing the impact of continuous vital signs monitoring with alerts to nurses on the incidence of postoperative complications in surgical ward patients. This thesis identified and evaluated issues with implementation of wireless monitoring systems in the hospital. During VIGILANCE study issues affecting the intervention implementation were documented on case report forms, alarm event forms, and nursing questionnaires. Data related to these issues were explored using the Clinical Adoption Framework. Identified issues included nursing workflow changes, patient withdrawal, wireless network connectivity, false alarms, monitor malfunction, probe issues, and wireless network standards. The issues affected ‘access’ through decreased ability of nurses to make complete use of the monitors; ‘care quality’ of the intervention through decreased effectiveness; and ‘productivity’ by interfering in the care coordination. Future studies should aim to include front-line nurses, appropriate wireless network, and comfortable cableless devices in their planning.
25

Predicting Arterial Oxygen Desaturation Events Via Patient Journal and Pulse Oximetry Data in Postoperative Ambulatory Surgery Patients

Elam, Charles R, IV 01 January 2018 (has links)
Associations between patient and procedural factors on the nature and quality of the immediate in-home recovery from anesthesia following ambulatory orthopedic surgery are unknown. Further, there is a paucity of outcomes research quantitatively categorizing in-home patient recovery and safety following discharge from same-day orthopedic procedures. Tools are available, however, to shed light on outcomes in this population, and integration of such available measures is critical. Ambulatory orthopedic surgery is a burgeoning specialty, with growth expected over the foreseeable future. The expected increased patient caseload subsequent to implementation of the Affordable Care Act and aging Baby Boom generation suggests greater morbidity and mortality is on the horizon unless aggressive measures are taken at mitigating risk. Similarly, as the obesity epidemic expands, obesity-related comorbid conditions including obstructive sleep apnea (OSA) are likely to grow. The purpose of this research was to explore the relationship between ambulatory orthopedic patient-reported activities (quality of life metrics) and diagnostic factors (physical and perioperative care data) in the immediate postoperative period that are predictive of arterial oxygen desaturation. Data was obtained using a novel patient journal exploring sleep, pain, nausea, tobacco use, alcohol use, and appetite in conjunction with a valid and reliable portable, wrist-worn pulse oximeter. Additional assessment data was taken from the preanesthetic assessment. All participants were scored according to the STOP-Bang questionnaire, an accepted survey of OSA risk. Patients were recruited from a busy metropolitan ambulatory surgery center in Richmond, Virginia that sees approximately 500 cases monthly, and a 309-bed tertiary care hospital in West Burlington, Iowa. The target sample included 52 individual patients with data collected over the first two post-operative nights following discharge. Two patients were excluded. Negative binomial regression, log10 transformation, and least-squares regression examined the relationships the STOP-Bang questionnaire, quality of life data, and physical perioperative data had on postoperative desaturation events. Results suggested the STOP-Bang score predicted desaturation events and that age and BMI were significant individual predictors. Opiate pain medication treatment, a happy mood, and home CPAP use were associated with decreased events. This study provided a unique perspective in patient safety research, relating human behaviors and experiences with postoperative oxygen desaturation. Future research projects aligned with postoperative monitoring, pulse oximetry, patient safety, and obstructive sleep apnea are potential following the findings of this study.
26

Ανάπτυξη συστήματος διάγνωσης εμβρυικής υποξίας και πρόληψης άμεσων και απώτερων σοβαρών επιπλοκών με εφαρμογή σύγχρονων τεχνικών επεξεργασίας και ανάλυσης σήματος

Βάσιος, Γρηγόριος 22 September 2009 (has links)
Τα τελευταία χρόνια τόσο σε διεθνές όσο και σε εθνικό επίπεδο έχει δοθεί βαρύτητα στην ανίχνευση της εμβρυϊκής υποξίας κατά τη διάρκεια της κύησης και του τοκετού, καθώς είναι σαφής η άμεση συσχέτισή της με βραχυπρόθεσμες και απώτερες επιπλοκές του νεογνού. Η επιτυχής έκβαση ενός τοκετού εξαρτάται κυρίως από τον έγκαιρο εντοπισμό της δημιουργίας της εμβρυϊκής υποξίας και η ανάγκη για την υλοποίηση υπολογιστικών συστημάτων για την έγκαιρη διάγνωσή της είναι συνεχής και αυξανόμενη. Στα πλαίσια της διδακτορικής διατριβής σχεδιάστηκε και αναπτύχθηκε ένα πρωτότυπο σύστημα διάγνωσης της πρόωρης οξέωσης του εμβρύου κατά τη διάρκεια του τοκετού, το οποίο βασίστηκε στην επεξεργασία του εμβρυϊκού καρδιακού ρυθμού και στην ανάλυση της εμβρυϊκής παλμικής οξυμετρίας. Στόχος του συγκεκριμένου συστήματος είναι να αποτελέσει ένα βοηθητικό σύστημα διάγνωσης της εμβρυϊκής υποξίας και να συμβάλει στη λήψη αποφάσεων σχετικά με το χρόνο αποπεράτωσης του τοκετού, με σκοπό την πρόληψη άμεσων και απώτερων σοβαρών νεογνικών επιπλοκών. Ειδικότερα, η υλοποίηση του προτεινόμενου συστήματος βασίστηκε στην εφαρμογή του συνεχούς μετασχηματισμού κυματιδίων και της προσαρμοστικής προσέγγισης με τη χρήση του αλγορίθμου matching pursuit για την ανάδειξη της «κρυμμένης» πληροφορίας που μεταφέρει ο εμβρυϊκός καρδιακός ρυθμός στις πολύ χαμηλές συχνότητες. Συνδυάζοντας τα αποτελέσματα των παραπάνω τεχνικών επεξεργασίας, και ιδιαίτερα του αλγορίθμου matching pursuit, με τον προσδιορισμό του συνολικού χρόνου χαμηλού κορεσμού του αρτηριακού εμβρυϊκού αίματος, υλοποιήθηκε, με τη χρήση ενός διαμεριστικού αλγορίθμου, το προτεινόμενο σύστημα. Η ανάπτυξη αυτού του συστήματος αποτελεί μια καινοτόμα και πολλά υποσχόμενη προσέγγιση στην προσπάθεια της διάγνωσης της εμβρυϊκής υποξίας δεδομένου ότι παρουσιάζει υψηλή ειδικότητα και θετική προγνωστική αξία συμβάλοντας στην επίλυση του σοβαρότερου μειονεκτήματος της κλασσικής καρδιοτοκογραφίας που είναι η χαμηλή τιμή των αντίστοιχων προγνωστικών δεικτών. / In the last few years the research community has given great attention to the detection of antepartum and intrapartum fetal hypoxia, given its direct impact on both short- and long-term neonatal morbidity and mortality. The successful completion of labor depends mainly on the prompt identification of fetal hypoxia. The development of computational systems for the early diagnosis of restricted fetal oxygen supply is therefore of critical importance. This thesis involves the design and development of an innovative system for the early detection of acidosis, which was based on the fetal heart rate processing and fetal pulse oximetry analysis. The aim of the system is to comprise a computer-aided diagnostic system of fetal hypoxia and to contribute to the decision making regarding the labor completion time, in order to prevent short- and long-term neonatal complications. Specifically, the development of the system was based on the implementation of continuous wavelet transform and adaptive approximation using the matching pursuit algorithm, in order to reveal the “hidden” information conveyed in the very low frequency range of the fetal heart rate. The system involves the combination of the results of the above-mentioned processing techniques, and especially of the matching pursuit algorithm, along with the calculation of the duration of fetal arterial low oxygen saturation, applying a commonly used clustering algorithm. The proposed system is an innovative and promising approach towards the early diagnosis of fetal hypoxia, given its high specificity and positive predictive value, thus effectively addressing the major drawback of clinical cardiotocography.
27

Μελέτη της απορρόφησης του φωτός από το ανθρώπινο δέρμα με σκοπό τη μέτρηση βιολογικών συντελεστών

Μανουσίδης, Ιωάννης 19 January 2010 (has links)
Τα τελευταία χρόνια, οι μη επεμβατικές μέθοδοι διάγνωσης αλλά και θεραπείας κερδίζουν συνεχώς έδαφος έναντι των παραδοσιακών επεμβατικών μεθόδων. Σκοπός της διπλωματικής αυτής εργασίας είναι η μελέτη της μετάδοσης του φωτός μέσα στο ανθρώπινο δέρμα και κυρίως η μελέτη της απορρόφησης που υφίσταται από αυτό, με σκοπό την μέτρηση βιολογικών συντελεστών, όπως οι συγκεντρώσεις κάποιων ουσιών στον οργανισμό, ο υπολογισμός των οποίων μπορεί να οδηγήσει σε χρήσιμα διαγνωστικά συμπεράσματα. Επίσης, αναλύεται η μέθοδος της παλμικής οξυμετρίας, που χρησιμοποιείται ευρύτατα για την παρακολούθηση του αρτηριακού κορεσμού οξυγόνου και του καρδιακού παλμού. Μετρώντας την απορρόφηση του φωτός σε δύο διαφορετικά μήκη κύματος, ένα στο ερυθρό (660 nm) και ένα στο εγγύς υπέρυθρο (940 nm), και απομονώνοντας το μεταβαλλόμενο μέρος αυτής, που οφείλεται στις διακυμάνσεις στον όγκο του αρτηριακού αίματος, μπορούμε να υπολογίσουμε με τη χρήση του νόμου των Beer-Lambert τον κορεσμό του αίματος σε οξυγόνο μέσω του υπολογισμού των συγκεντρώσεων του σε μειωμένη αιμογλοβίνη και σε οξυαιμογλοβίνη. Τέλος, περιγράφεται η υλοποίηση της μεθόδου και ο σχεδιασμός ενός παλμικού οξυμέτρου ενός chip με τη χρήση του μικροεπεξεργαστή MSP430. / Over recent years, non-invasive methods of diagnosis and treatment are gaining ground against the traditional invasive methods. In this thesis, an integrated review of the transfer of optical radiation into human skin and primarily light absorption through human skin is presented, aiming at measuring biological information, such as concentrations of certain substances in the human body, whose calculation can lead to useful diagnostic conclusions. The method of Pulse Oximetry, which is widely used for monitoring arterial oxygen saturation and heart rate of a patient, is also presented. By measuring the absorption of light at two different wavelengths, one red (660 nm) and one near-infrared (940 nm), and isolating its AC component, which is a result of the variations in the volume of arterial blood, we can calculate the oxygen saturation using the Beer-Lambert law, by estimating the concentrations of oxyhemoglobin and reduced hemoglobin. Moreover, the implementation of a single chip portable pulse oximeter using the ultra low power capability of the MSP430 is demonstrated.
28

Development of a Signal Processing Library for Extraction of SpO2, HR, HRV, and RR from Photoplethysmographic Waveforms

Johnston, William S. 31 July 2006 (has links)
"Non-invasive remote physiological monitoring of soldiers on the battlefield has the potential to provide fast, accurate status assessments that are key to improving the survivability of critical injuries. The development of WPI’s wearable wireless pulse oximeter, designed for field-based applications, has allowed for the optimization of important hardware features such as physical size and power management. However, software-based digital signal processing (DSP) methods are still required to perform physiological assessments. This research evaluated DSP methods that were capable of providing arterial oxygen saturation (SpO2), heart rate (HR), heart rate variability (HRV), and respiration rate (RR) measurements derived from data acquired using a single optical sensor. In vivo experiments were conducted to evaluate the accuracies of the processing methods across ranges of physiological conditions. Of the algorithms assessed, 13 SpO2 methods, 1 HR method, 6 HRV indices, and 4 RR methods were identified that provided clinically acceptable measurement accuracies and could potentially be employed in a wearable pulse oximeter."
29

Monitoring of Splanchnic Regional Perfusion : An Experimental Study of New Application and Validation

Koga, Itaru January 2003 (has links)
<p>Systemic infection, major surgery, trauma and many other causes can lead to impaired organ function. Compensated shock is not detected by global hemodynamic and oxygen measurements, as they take no account for regional variations. Focus has therefore gradually turned from looking at systemic changes to selective investigations of regional blood flow and ischemia. This thesis presents a series of experiments evaluating new application and validation of various monitoring techniques.</p><p>An experimental porcine model with anesthetized and invasively monitored animals was used. The circulatory interventions included endotoxin infusion (septic shock), aortic constriction and selective clamping of splanchnic arteries. The aim was to compare air with saline tonometry, to validate the intraperitoneal use of tonometry and to reexamine the use of endoluminal reflectance pulse oxymetry. To investigate the relative contributions of regional blood flow and detection of ischemia, measurements of hepatic venous oxygen saturation (ShvO<sub>2</sub>), lactate concentrations and PCO<sub>2</sub> gap were used.</p><p>Our findings support the use of air instead of saline as the preferred technique for tonometric measurements. With the intraperitoneal application of tonometry we gain more information on regional aspects of the splanchnic circulation, and it appears to be a reliable monitoring option for early detection of ischemia in the small intestine. Measurements of ShvO<sub>2 </sub>will give an overall reflection of the intestinal circulation. The sigmoid colonic pulse oximetry showed a non-linear response in relation to regional blood flow, and will therefore not be able to detect gradual changes in oxygen saturation. Determination of the regional to endtidal PCO<sub>2</sub> gap might prove valuable for monitoring of the intestinal circulation.</p><p>Because of sophisticated interactions between portal and hepatic arterial blood flow and hepatic compensation for regional ischemia, a combination of monitoring techniques might be needed. The results of this study will hopefully encourage clinical evaluation of intraperitoneal tonometry and endtidal PCO<sub>2</sub> gap recordings for non-invasive, semi-continuous, trend monitoring of the splanchnic circulation.</p>
30

Monitoring of Splanchnic Regional Perfusion : An Experimental Study of New Application and Validation

Koga, Itaru January 2003 (has links)
Systemic infection, major surgery, trauma and many other causes can lead to impaired organ function. Compensated shock is not detected by global hemodynamic and oxygen measurements, as they take no account for regional variations. Focus has therefore gradually turned from looking at systemic changes to selective investigations of regional blood flow and ischemia. This thesis presents a series of experiments evaluating new application and validation of various monitoring techniques. An experimental porcine model with anesthetized and invasively monitored animals was used. The circulatory interventions included endotoxin infusion (septic shock), aortic constriction and selective clamping of splanchnic arteries. The aim was to compare air with saline tonometry, to validate the intraperitoneal use of tonometry and to reexamine the use of endoluminal reflectance pulse oxymetry. To investigate the relative contributions of regional blood flow and detection of ischemia, measurements of hepatic venous oxygen saturation (ShvO2), lactate concentrations and PCO2 gap were used. Our findings support the use of air instead of saline as the preferred technique for tonometric measurements. With the intraperitoneal application of tonometry we gain more information on regional aspects of the splanchnic circulation, and it appears to be a reliable monitoring option for early detection of ischemia in the small intestine. Measurements of ShvO2 will give an overall reflection of the intestinal circulation. The sigmoid colonic pulse oximetry showed a non-linear response in relation to regional blood flow, and will therefore not be able to detect gradual changes in oxygen saturation. Determination of the regional to endtidal PCO2 gap might prove valuable for monitoring of the intestinal circulation. Because of sophisticated interactions between portal and hepatic arterial blood flow and hepatic compensation for regional ischemia, a combination of monitoring techniques might be needed. The results of this study will hopefully encourage clinical evaluation of intraperitoneal tonometry and endtidal PCO2 gap recordings for non-invasive, semi-continuous, trend monitoring of the splanchnic circulation.

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