Background: Despite the recent improvements in surgical techniques and postoperative patient care, atrial fibrillation (AF) remains the most frequent complication after cardiac surgery. Although postoperative AF is often regarded as a benign clinical condition, this arrhythmia has significant adverse effects on patient recovery and postoperative survival. Its exact pathophysiology has not yet been elucidated. The present thesis aims to analyze AF risk factors and their interaction, pre-existing histological explanatory alterations of the atrium, the AF impact on postoperative survival and the compliance of a prophylactic drug regimen. Methods: During a 10-year period, consecutive cardiac surgery cases with complete data on AF occurrence and postoperative survival were extracted. All patients were operated on for coronary or valvular surgery, with cardiopulmonary bypass (CPB). Hospital and long-term survival data were obtained from Swedish population registry. Study I) Isolated coronary artery bypass grafting (CABG, n=7056), aortic valve replacement (n=690) and their combination (n=688) were considered. Independent AF risk factors and AF effects on early and 1 year mortality were investigated. Study II) Patients affected by postoperative AF among isolated CABG patients (n=7621), valvular surgeries (n=995) and their combination (n=879) were studied. Long-term survival was obtained and prognostic factors identified. Study III) Seventy patients were randomized to on-pump (n=35) or off-pump (n=35) CABG. Samples from the right atrial appendage were collected and histology was evaluated by means of light and electronic microscopy with reference to preexistent alterations related to postoperative AF. Study IV) Cardiac surgery patients with complete data on smoking status (n=3245) were reviewed. Effects of smoking on AF development and interaction among variables were explored. Study V) CABG patients without clinical contraindications to receive oral sotalol (80 mg twice daily) and magnesium were prospectively enrolled (n = 49) and compared with a matched contemporary control CABG group (n = 844). The clinical compliance to the AF prophylactic drug regimen was tested. Results: The overall AF incidence was around 26%, subdivided into 23%, 40% and 45% for isolated CABG, valve procedures and their combined surgeries, respectively. Age was the strongest predictor of postoperative AF. Coronary disease superimposed risk factors with reference to myocardial conditions at CPB weaning. Considering the preoperative smoking condition, smokers demonstrated a reduced AF incidence compared to non-smokers (20% versus 27%, p<0.001). An interaction between smoking status and inotropic support was observed: without this interaction smoking conferred a 46% risk reduction of AF (p=0.011). At the histological level, myocyte vacuolization and nuclear derangement represented anatomical independent AF predictors (p=0.002 and p=0.016, respectively). CPB exposure was not associated to postoperative AF nor histological changes. Although, postoperative AF increases the length of hospitalization in all patient groups, it did not affect the hospital survival. However, AF independently impaired the late survival, a phenomenon seen in the CABG group only. With reference to the tested sotalolmagnesium drug regimen, only 55% of CABG patients were compliant to the treatment, with marginal effects on AF occurrence. Conclusions: In addition to age, details at the CPB weaning period, pre-existing histopathological changes, the hyperadrenergic state and catecholamines are key mechanisms in the pathophysiology of postoperative AF. In particular, the CPB period hides valuable information for timely AF prophylactic stratifications. Further, compliance effects due to patient selection should also be considered in a prophylactic therapy model. Postoperative AF increases late mortality after isolated CABG surgery, but not after valvular procedures. Although the mechanisms are unclear, our results draw the attention to possible AF recurrence after hospital discharge, indicating a strict postoperative surveillance.

Introduction: During cardiac surgery aided by cardiopulmonary bypass (CPB) the autotransfusion of pericardial suction blood (PSB) is regarded mandatory to limit allogeneic blood exposure. PSB is however proposed as a source of lipid microemboli and to contribute to brain damage. This thesis addresses the logistics of allogeneic blood transfusion during coronary artery bypass grafting (CABG), the embolic potential of reinfused PSB, and means to reduce PSB fat contamination, investigated both clinically and experimentally. Methods: Study I) Patients undergoing CABG surgery (n=2469) were included in a database study. The magnitude of surgical bleeding versus blood transfusion was analyzed to extract a subgroup of patients (n=982) in whom transfusions were independent from bleeding. Study II) PSB and venous-blood samples were collected from patients undergoing routine CABG (n=20). The in vitro capillary-flow properties of blood subcomponents and the effects of routine screen filtration were tested. PSB fat contamination was evaluated by imprint microscopy. Study III) Heat extracted liquid human fat or soya oil were mixed with mediastinal drain blood (n=20) and incubated in a temperature controlled column, to evaluate spontaneous density separation of fat. Study IV) The findings from study-III were applied to develop a fat-reducing system (FRS) using two stacked compartments. The FRS was experimentally tested (n=12), with similar methods as in study-III, and clinically evaluated (n=10). A single-chamber blood bag (n=10) served as reference. Results: Study I) A surgical bleeding of less than 400 mL showed no correlation to blood transfusion, although 64 of 982 patients still received allogeneic blood. The strongest predictors for this kind of transfusion were; female gender, weight ≤70 kg, CPB time ≥90 minutes, CPB temperature ≤32 ºC, and advanced age (P<.001 - .038). Study II) The capillary-flow profile of PSB plasma was highly impaired compared to venous plasma (P<.001). Conversely, blood-cell components showed no difference between PSB and venous blood. Routine screen filtration showed no ameliorating effect on capillary-flow resistance. Fat debris was detected on imprints in all PSB samples in contrast to venous plasma (P<.05). Study III) After 10-min of incubation had 77% of added soya oil separated and found contained in the top 20% fraction of blood (P<.001), aimed to be discarded. The density separation of human fat was less efficient compared to soya oil (P=.011). Fat also adsorbed to surface which was more pronounced at low temperature (P<.001). The overall reduction of human fat was 70%. Study IV) PSB contained 1.5 mL fat suspended in 418 mL PSB. Of this fat was 24% surface-bound. Experimental analysis of the proposed FRS revealed an 83% fat-reduction which was clinically confirmed, suggesting 80% reduction (P=.001). The FRS also gave a small but significant erythrocyte-concentrating effect. Conclusions: Transfusion of allogeneic blood during CABG surgery appeared associated with an institutional, individual, and technical bias of an anticipated need and not only used to compensation for surgical bleeding. In part may this reflect a non-compliant CPB methodology and hemodilution. It was confirmed that PSB plasma contained fat, with a suggested embolic potential. Human fat was significantly reduced from mediastinal drain blood by spontaneous density separation and surface adsorption. The prototype FRS used for PSB incubation during CPB allowed an efficient fat reduction.

Det råder delade meningar angående närståendes närvaro under hjärt-lungräddning på sjukhus. Trots internationella riktlinjer från Emergency Nursing Association som säger att närstående bör erbjudas möjlighet att närvara under hjärt- lungräddning så följs ej dessa generellt på sjukhusen. Syftet: Var att beskriva närståendes upplevelser att närvara under hjärt-lungräddning på sjukhus. Metod: En litteraturstudie har gjorts där 13 vetenskapliga artiklar har granskats. Resultat: Närstående ville ha en valmöjlighet om de skulle närvara eller ej. De flesta närstående var nöjda med sitt beslut att närvara och skulle göra det igen trots att situationen upplevdes som svår. Närstående kände samhörighet med patienten och upplevde att de hanterade situationen bättre om de fick kontinuerlig information om händelseförloppet samt hade en stödperson vid sin sida. Sorgen underlättades då de delat den sista stunden med sin närstående. Slutsats: Närståendes närvaro under hjärt-lungräddning är fortfarande ett relativt outforskat område. Valmöjligheten att närvara är viktig, likaså kontinuerlig information och att ha en stödperson hos sig under hjärt-lungräddningen anses väsentligt. Närstående som varit närvarande under hjärt- lungräddning uppvisar lägre tendens till negativa psykologiska effekter och upplever även att sorgeprocessen underlättas. / A difference of opinion exists regarding the issue of relatives being present during cardiopulmonary resuscitation in hospital. Despite international guidelines from the Emergency Nursing Association stating that relatives should be offered the opportunity to be present during cardiopulmonary resuscitation, this is generally not the case. The aim: of this study was to describe relatives' experiences of being present during cardiopulmonary resuscitation in hospital. Method: A literature review in which 13 scientific papers have been reviewed. Results: Relatives preferred to be given the option to attend the cardiopulmonary resuscitation or not. Most relatives were satisfied with their decision to attend and would do it again even though the situation was perceived as difficult. Relatives experienced an emotional connection with the patient and felt that they handled the situation better if they were given continuous information on the events and had a support person at their side. Relatives also felt it easier to cope with the grieving process when they had shared their loved ones last moment. Conclusion: The attendance of relatives during cardiopulmonary resuscitation is still a relatively unexplored area. To be given the option to attend or not is important, as is continuous information during the resuscitation as well as a support person throughout the process. Relatives who were present during resuscitation showed lower tendency to experience negative psychological effects, and that the grieving process felt easier to go through.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Sjuksköterskor har en nära relation till patienter och anhöriga och bör efter bästa förmåga möjliggöra deras delaktighet i vården. Trots att riktlinjer om hjärt-lungräddning (HLR) menar att beslutskompetenta patienter ska vara delaktiga i beslutet om ej-HLR, fungerar det inte alltid så i praktiken. I och med detta kan sjuksköterskor få svårt att hantera situationer som uppstår kring beslutet om ej-HLR. Syftet var att belysa patienters respektive anhörigas delaktighet i beslutet om ej-HLR. Studien genomfördes som en litteraturstudie och 15 vetenskapliga artiklar analyserades. Studiens resultat visar att patienters och anhörigas delaktighet i beslutet om ej-HLR påverkas av olika faktorer så som patienters livskvalité, information om sjukdom, prognos och HLR. Anhöriga vill och får ofta möjlighet att delta i ett beslut om ej-HLR. Anhörigas möjlighet till delaktighet beror främst på patienters beslutskompetens och det är läkare som möjliggör patienters och anhörigas delaktighet i beslutet om ej-HLR. Sjuksköterskors samarbete med läkare i diskussionen om ej-HLR kan underlätta beslutsprocessen för samtliga parter. För att patienters och anhörigas delaktighet ska främjas bör riktlinjerna för beslut angående HLR ses över och möjligen uppdateras. / The nurse has a close relationship with patients and families and should promote the potential of their involvement in care. The medical practice differs from guidelines for cardiopulmonary resuscitation (CPR) which suggests that patients should be involved in the decision making about the do-not-resuscitate (DNR) order. Nurses may find it difficult to deal with situations that arise over the decision about DNR. The aim was to illuminate patients' and relatives' participation in the decision making concerning the DNR order. The study was conducted as a literature study and 15 scientific articles were analyzed. The results show that involvement of patient and next-of-kin in the decision not to resuscitate can be affected by various factors. Factors that could affect patient participation were patients’ quality of life, knowledge about disease, prognosis and CPR. Family members often want and often get the opportunity to participate in the decision making concerning DNR. Relatives' ability to participate depends primarily on patients' ability to participate in the decision making. Doctors enable patients and families participation in the decision not for resuscitation. Nurses’ collaboration with doctors in the discussion about the DNR order can facilitate decision making for all parties. The guidelines for decision about CPR should be reviewed and possibly updated in order to improve patients' and relatives' participation.

Abdominelle Komplikationen, zu denen auch das akute Leberversagen nach Einsatz der Herz-Lungen-Maschine und systemischer Hypothermie nach herzchirurgischen Korrekturoperationen neugeborener Patienten zählt, sind seltene, aber dennoch erst zu nehmende unerwünschte Folgen. Die Untersuchungen erfolgten an neugeborenen Schweinen, die in 4 Gruppen eingeteilt wurden: Eine Gruppe wurde mit extrakorporaler Zirkulation in moderater Hypothermie (32°C) operiert (CPB), die zweite Gruppe wurde in tiefer Hypothermie (18°C) und totalem Kreislaufstillstand operiert (DHCA). In der dritten Gruppe (Sham) erfolgte die Instrumentation nach Sternotomie und ohne Einsatz der Herz-Lungen-Maschine. Die Tiere der vierten Gruppe waren unbehandelte Kontrolltiere. Es zeigte sich, dass das Entstehen der Inflammation wesentlich abhängig von der Anwendungsdauer der Herz-Lungen-Maschine ist. Tiefe systemische Hypothermie scheint einen protektiven Effekt auf die Inflammation und Apoptose zu haben. Im Gegensatz dazu verursacht tief-hypothermer Kreislaufstillstand vermehrt die Bildung eines hepatozellulären Ödems. Bei allen untersuchten Aspekten (Inflammation, hepatozelluläres Ödem, Apoptose) zeigt sich deutlich, dass der operative EIngriff selbst Veränderungen an der Leber hervorruft. Insbesondere für das Auftreten von Apoptose ist das chirurgsiche Trauma von größter Bedeutung.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Bakgrund: Dödligheten vid hjärtstopp utanför sjukhus är hög och endast några få procent av de som drabbas räddas till livet. Tidig behandling är en avgörande faktor för överlevnad. Överlevnaden kan ökas markant av att människor på platsen, bystanders, ingriper med hjärt-lungräddning (HLR). Att vårda och utföra vårdhandlingar är inte exklusivt för sjuksköterskor. Vid hjärtstopp utanför sjukhus är det istället bystandern som förväntas utföra vårdhandlingen. I många fall sker dock inget ingripande trots att hjärtstoppet bevittnas och den vårdande handlingen uteblir därför. Syfte: Syftet med arbetet var att identifiera faktorer som påverkar människors vilja att ingripa vid hjärtstopp utanför sjukhus. Metod: Arbetet designades som en litteraturstudie där artiklar med både kvantitativ och kvalitativ ansats ingick. Resultat: Resultatet baserades på potentiella bystanders antaganden av hur de skulle agera och faktiska bystanders erfarenheter av att ha agerat. Skillnader i faktorer som påverkade viljan observerades mellan dessa. Viljan påverkades till stor del av rädslor, bristande HLR-kunskaper samt scenariot kring hjärtstoppet där bland annat en familjerelation mellan den drabbade och bystandern utgjorde en påverkande faktor. Slutsats: Resultatet visar att hindrande faktorer för viljan skulle kunna påverkas positivt genom förbättrad HLR-utbildning. Klinisk betydelse: Med hjälp av identifierade faktorer kan befintlig HLR-utbildning ses över och eventuellt förbättras. Detta skulle kunna öka antalet ingripanden och därigenom överlevnaden vid hjärtstopp utanför sjukhus. / Background: The lethality is high in out-of-hospital cardiac arrests and only a few percent of the victim’s lives are saved. Early treatment is crucial for survival. People at the scene can increase the survival significantly through CPR interventions. To care and the act of caring is not exclusively for nurses. In cases of out-of-hospital cardiac arrest, the bystander could be the one that performs the act of caring. In many cases, however, no interventions are made although the arrest is witnessed and therefore no act of caring is being performed. Objective: The aim of this essay was to identify factors that influence people's willingness to intervene in out-of-hospital cardiac arrest. Method: This study was designed as a literature study and both quantitative and qualitative research articles were included in the analysis. Results: The result was based on potential bystander's assumptions of how they would act and actual bystanders experience having acted. Differences in factors affecting the willingness were observed between them. The will seemed influenced by fears, lack of CPR skills and the scenario surrounding the arrest. A family tie between the victim and the bystander appeared also as an influencing factor. Conclusion: The findings show that the non-willingness to act could be affected positively by improved CPR training. Clinical significance: In light to the identified factors, improvement of the existing CPR training and increased education could improve the probability of intervention by bystanders and out-of-hospital cardiac arrest survival.

This thesis investigated whether out­come after in-hospital cardiac arrest patients could be improved by a cardiopulmonary resuscitation (CPR) educational intervention focusing on all hospital healthcare professionals. Annually in Sweden, approximately 3000 in-hospital patients suffer a cardiac arrest in which CPR is attempted, and which 900 will survive. The thesis is based on five papers: Paper I was a methodological study concluding in a reliable multiple choice questionnaire (MCQ) aimed at measuring CPR knowledge. Paper II was an intervention study. The intervention consisted of educating 3144 healthcare professionals in CPR. The MCQ from Paper I was answered by the healthcare professionals both before (82% response rate) and after (98% response rate) education. Theoretical knowledge improved in all the different groups of healthcare professionals after the intervention. Paper III was an observational laboratory study investigating the practical CPR skills of 74 healthcare professionals’. Willingness to use an automated external defibrillator (AED) improved generally after educa­tion, and there were no major differences in CPR skills between the different healthcare professions. Paper IV investigated, by use of a questionnaire, the attitudes to CPR of 2152 healthcare professionals (82% response rate). A majority of healthcare professionals reported a positive attitude to resuscitation. Paper V was a register study of patients suffering from cardiac arrest. The intervention tended not to reduce the delay to start of treatment or to increase overall survival. However, our results suggested indirect signs of an improved cerebral function among survivors. In conclusion, CPR education and the introduction of AEDs in-hospital – improved healthcare professionals knowledge, skills, and attitudes – did not improve patients’ survival to hospital discharge, but the functional status among survivors improved.

Μελέτη της αναπνευστικής λειτουργίας με εργοσπιρομετρία σε ασθενείς με γαστροοισοφαγική παλινδρομική νόσο. Εισαγωγή: Η Γαστροοισοφαγική Παλινδρομική Νόσος (ΓΟΠΝ) έχει συσχετισθεί με πλειάδα πνευμονικών εκδηλώσεων αλλά είναι ασαφές εάν η γαστροοισοφαγική παλινδρόμηση προκαλεί οποιαδήποτε δυσλειτουργία στην πνευμονική λειτουργία. Η εργοσπιρομετρία είναι μια εξειδικευμένη μέθοδος η οποία χρησιμοποιείται για να διερευνήσει την αναπνευστική λειτουργία κατά την άσκηση. Σκοπός: Σκοπός της μελέτης ήταν να αποκαλυφθεί οποιαδήποτε ανωμαλία της πνευμονικής λειτουργίας σε ασθενείς με ΓΟΠΝ και αναπνευστικά συμπτώματα. Μέθοδος: Μελετήσαμε 34 ασθενείς με ΓΟΠΝ (ηλικίας 21-63, 24 άνδρες/10 γυναίκες) και εξωοισοφαγικά αναπνευστικά συμπτώματα (συριγμός ή/και βήχας) πριν και μετά από 12 εβδομάδες θεραπεία με διπλή δόση ομεπραζόλης. Κανείς ασθενής δεν παρουσίασε παθολογική σπιρομέτρηση. Εργομετρία διενεργήθηκε σε όλους του ασθενείς πριν την θεραπεία και μετά την θεραπεία. Γαστροσκόπηση διενεργήθηκε σε όλους τους ασθενείς πριν την θεραπεία και σε αυτούς με οισοφαγίτιδα επανελήφθη μετά την θεραπεία. Καταγραφήκαν οι ακόλουθες εργομετρικές παράμετροι: VO2rest, VO2max, VCO2rest, VCO2max, O2–puls rest, O2–puls max, HR (heart rate) rest, HRmax, PETCO2rest, PETCO2max, VE/VCO2 SLOPE πριν και μετά την θεραπεία. Αποτελέσματα: Είκοσι τέσσερις ασθενείς (70.6%) είχαν οισοφαγίτιδα (βαθμού Α-D), 16 ασθενείς είχαν διαφραγματοκήλη (47.1%), και σε 13 ασθενείς (38.23 %) ανιχνεύθηκε Helicobacter pylori.Οι εργομετρικές παράμετροι ήταν εντός φυσιολογικών ορίων σε όλους τους ασθενείς, κανείς ασθενής δεν παρουσίασε οποιαδήποτε ανωμαλία κατά την άσκηση. Είκοσι οκτώ ασθενείς επανελέγχθηκαν. Καμία βελτίωση σε οποιαδήποτε εργομετρική παράμετρο μετά την θεραπεία δεν παρατηρήθηκε παρά την ύφεση των οισοφαγικών και των εξωοισοφαγικών συμπτωμάτων σε όλους τους ασθενείς. Καμία στατιστικώς σημαντική διαφορά δεν παρατηρήθηκε πριν και μετά την θεραπεία μεταξύ ασθενών μεγαλύτερων των 40 ετών και νεότερων των 40 ετών, καπνιστών και μη καπνιστών, Hp(+) και Hp(-) ασθενών, όπως επίσης και μεταξύ ασθενών με και χωρίς οισοφαγίτιδα, και μεταξύ ασθενών με και χωρίς διαφραγματοκήλη. Συμπεράσματα: Ασθενείς με ΓΟΠΝ, αναπνευστικές εκδηλώσεις και φυσιολογική σπιρομέτρηση, δεν παρουσιάζουν διαταραχές κατά την εργομετρία (δοκιμασία άσκησης). Επίσης δεν παρατηρείται καμιά κλινικά αξιόλογη μεταβολή στις εργομετρικές τιμές μετά την θεραπεία ούτε διαφορά στις εργομετρικές τιμές σύμφωνα με την ηλικία, το κάπνισμα, την παρουσία H.pylori, οισοφαγίτιδας ή διαφραγματοκήλης. / Evaluation of respiratory function with cardiopulmonary exercise test in patients with gastroesophageal reflux disease. Introduction: Gastroesophageal reflux disease (GERD) has been associated with a variety of pulmonary manifestations but it is unclear if gastroesophageal reflux causes any abnormality in pulmonary function. Cardiopulmonary exercise test (CPET) is a specialized method which is used to evaluate respiratory function during exercise. Aim: The aim of this study was to reveal any abnormality of pulmonary function in patients with GERD and respiratory symptoms. Method: We evaluated 34 patients with GERD (age 21-63, 24 men) and extraesophageal respiratory symptoms (wheezing and/or cough) before therapy and after twelve weeks treatment with double dose omeprazole. No patient presented abnormal spirometry. CPET was performed in all patients at baseline and after completion of 12 week treatment. The following CPET parameters: VO2rest, VO2max, VCO2rest, VCO2max, O2–pulse rest, O2–pulse max, HR (heart rate) rest, HRmax, PETCO2rest, PETCO2max, VE/VCO2 slope were recorded pre-treatment and post-treatment. Results: Twenty four patients (70.6%) had esophagitis (grade I-IV), 16 patients had hiatal hernia (47.1%) and in 13 patients (38,2%) Helicobacter pylori was positive. All patients completed the CPET. No one presented shortness of breath or respiratory symptoms. CPET parameters were within normal limits in all patients. Twenty eight patients were reevaluated. No improvement in any CPET parameter post treatment was observed despite remission of esophageal and extraesophageal symptoms in all patients. No statistically significant difference was observed pre and post-treatment, between older and younger than 40 year old patients, smokers and non smokers, Hp(+) and Hp(-) patients and those with and without hiatal hernia and esophagitis. Conclusions: Patients with GERD and respiratory manifestations and normal spirometry present no pulmonary dysfunction during CPET. Also no alterations in CPET values post-treatment neither differences in CPET values according to age, smoking, Hp status, presence of oesophagitis or hiatal hernia were observed.