Hemodynamic Collapse after Coronary Artery Bypass Grafting

Sudden hemodynamic collapse after coronary artery bypass surgery is a major complication associated with high mortality and morbidity. There are many well-established risk stratification systems to assess the risk of mortality and morbidity after cardiac surgery. These risk scores, however, do not predict severe immediate postoperative complications such as sudden hemodynamic collapse. This study is based on analysis of patients who suffered from hemodynamic collapse early after coronary artery bypass surgery between 1988 and 1999 in Helsinki University Hospital. One matched control patient was selected for every study patient. Patients, who died, underwent a medico-legal autopsy and a rubber cast angiography to reveal possible surgical errors in myocardial revascularization. Patients still alive in 2009 were traced with respect to mortality data and a health-related quality of life questionnaire was sent to the patients and to the controls. In addition, a comparison was made between patients who suffered from postoperative hemodynamic collapse and patients who underwent a postoperative angiography due to persistent myocardial ischemia. Angiography was introduced in 2000 and this patient series was collected prospectively between 2000 and 2007. This thesis consists of four studies. The specific goals were to explore predictive factors of sudden hemodynamic collapse, to reveal the possible surgical errors that led to hemodynamic collapse and fatal outcome with the means of an autopsy, to find out the impact that postoperative angiography has on the incidence of hemodynamic collapse, and the rate of mortality, and morbidity of patients, and to investigate the quality of life of patients surviving hemodynamic collapse in comparison with an age- and sex-matched national reference population. The results suggest the following: Sudden hemodynamic collapse after CABG is a major complication with high mortality. Inadequate tissue perfusion, postoperative myocardial ischemia, and increased need for inotropic as well as mechanical support are predictive of hemodynamic collapse. Technical graft complications are a major underlying cause of postoperative hemodynamic collapse. Post-mortem angiography improves the accuracy of diagnostics of graft complications. The cause of death could be established in every case. Use of early postoperative angiography in case of hemodynamic compromise or myocardial ischemia reduces the rate of emergency reoperations and decreases morbidity and mortality. It also allows treatment with intravascular medication. Patients who survive hemodynamic collapse and emergency reoperations have a similar prognosis as matched control patients. Health-related quality of life that is also comparable with age- and sex-matched national reference population as long as 15 years postoperatively.Verenkierron romahdus sepelvaltimo-ohitusleikkauksen jälkeen on komplikaatio, johon liittyy korkea kuolleisuus ja sairastavuus. Sepelvaltimokirurgian jälkeistä kuolleisuuden ja sairastavuuden arvioimista varten on kehitetty monia riskipistejärjestelmiä. Näiden järjestelmien heikkous on kuitenkin se, että ne eivät ennusta välittömiä leikkauksen jälkeisiä ongelmia, kuten verenkierron romahdusta. Tämä tutkimuskokonaisuus perustuu mittavaan analyysiin sepelvaltimokirurgisista potilaista, joiden verenkierto romahti leikkauksen jälkeen vuosien 1988 ja 1999 välillä Helsingin Yliopistollisessa keskussairaalassa. Jokaiselle tutkimuspotilaalle valittiin samankaltainen kontrollipotilas. Kaikille kuolleille potilaille suoritettiin oikeuslääketieteellinen ruumiinavaus ja sepelvaltimoiden varjoainetutkimus. Tämän lisäksi vertailtiin verenpaineen romahduksen saaneita potilaita potilaisiin, joille tehtiin varhaisen sydänlihaksen hapenpuutteen vuoksi varjoainekuvaus leikkauksen jälkeen. Tämä potilasaineisto on vuosien 2000 ja 2009 väliltä. Vuonna 2009 elossa olleille potilaille lähetettiin elämänlaatukyselykaavake. Tavoitteena oli selvittää ennakoivia tekijöitä, jotka johtavat verenkierron romahdukseen sepelvaltimokirurgian jälkeen. Selvittää oikeuslääketieteellisellä ruumiinavauksella mahdolliset kirurgiset virheet jotka johtivat potilaan romahdukseen ja kuolemaan. Lisäksi selvitettiin, vaikuttiko sepelvaltimoleikkauksen jälkeinen varjoainetutkimus kuolleisuuteen, sairastavuuteen ja teho-osastolla tapahtuneiden elvytysten määrään. Lopuksi selvitettiin verenkierron romahduksesta selvinneiden potilaiden pitkäaikaiselämänlaatua. Tulokset osoittavat, että yhtäkkinen verenkierron romahdus sepelvaltimokirurgian jälkeen on komplikaatio, johon liittyy suuri kuolleisuus. Kudosten riittämätön verensaanti, leikkauksen jälkeinen sydänlihaksen hapenpuute ja lisääntynyt verenkiertoa ja sydämen tehoa lisäävien lääkkeiden tarve ennustavat kohonnutta riskiä leikkauksen jälkeiselle verenkierron romahdukselle. Tekninen virhe sepelvaltimoiden ohituksessa osoittautui suurimmaksi syyksi leikkauksen jälkeiselle romahdukselle. Kuoleman jälkeinen sepelvaltimoiden varjoainekuvaus parantaa oikeuslääketieteellisen ruumiinavauksen diagnostiikkaa kuolemaan johtaneissa sepelvaltimo-ohitussiirteiden ongelmissa. Leikkauksen jälkeisen sydänlihaksen hapenpuutteen takia tehdyt sepelvaltimoiden varjoainekuvaukset vähensivät elvytyksien sekä sitä seuraavien hätäleikkausten määrää, kuten myös kuolleisuutta ja sairastavuutta. Varjoainetutkimuksen yhteydessä voidaan ongelmia myös hoitaa suoraan kohteeseen annettavilla lääkkeillä. Potilaat, jotka selviävät vakavasta verenkierron leikkauksenjälkeisestä romahduksesta, saavuttavat kontrollipotilaisiin verrattuna vastaavan pitkäaikaisennusteen. Myös elämänlaatu on vertailukelpoinen kontrollipotilaiden kanssa, kuten myös ikä- ja sukupuolivakioitujen verrokkien kanssa vielä 15 vuotta leikkauksen jälkeen

On dimension reduction in Gaussian filters

A priori dimension reduction is a widely adopted technique for reducing the computational complexity of stationary inverse problems. In this setting, the solution of an inverse problem is parameterized by a low-dimensional basis that is often obtained from the truncated Karhunen-Loeve expansion of the prior distribution. For high-dimensional inverse problems equipped with smoothing priors, this technique can lead to drastic reductions in parameter dimension and significant computational savings. In this paper, we extend the concept of a priori dimension reduction to non-stationary inverse problems, in which the goal is to sequentially infer the state of a dynamical system. Our approach proceeds in an offline-online fashion. We first identify a low-dimensional subspace in the state space before solving the inverse problem (the offline phase), using either the method of "snapshots" or regularized covariance estimation. Then this subspace is used to reduce the computational complexity of various filtering algorithms - including the Kalman filter, extended Kalman filter, and ensemble Kalman filter - within a novel subspace-constrained Bayesian prediction-and-update procedure (the online phase). We demonstrate the performance of our new dimension reduction approach on various numerical examples. In some test cases, our approach reduces the dimensionality of the original problem by orders of magnitude and yields up to two orders of magnitude in computational savings

Maatalouden monivaikutteisten kosteikkojen suunnittelu ja mitoitus

Kosteikkojen määrän odotetaan kasvavan maatalouden vesiensuojelun menetelmänä merkittävästi lähivuosina. Tähän tarpeeseen koottiin viimeisin tutkimus- ja kokemuspohjainen tieto uusiksi suunnittelu- ja mitoitusohjeistoiksi. Hankkeen tavoitteena oli i) luoda kosteikkojen alueellista ja paikallista yleissuunnittelua koskevat periaatteet ja kriteerit sekä ii) laatia monivaikutteisten vesiensuojelukosteikkojen tavoitteisiin perustuva suunnittelu- ja mitoitusohjeisto käytännön suunnittelijoille. Tässä julkaisussa esitetään rakennettujen kosteikkojen ratkaisuja ja niiden rakenteellisia yksityiskohtia, käydään läpi suunnittelun ja mitoituksen keskeiset periaatteet, käsitellään kenttätutkimusta ja suunnittelussa tarvittavia taustatietoja sekä arvioidaan kosteikkojen avulla saatavia ympäristö- ja muita hyötyjä. Kosteikkojen puhdistusmekanismeja ja niiden vaikutuksia esitetään suunnittelun ja mitoituksen taustatiedoiksi. Julkaisussa käsitellään pelkästään maatalouden monivaikutteisia kosteikoita, joissa vesiensuojelutavoitteet yhdistetään useisiin muihin tavoitteisiin, kuten esim. luonnon monimuotoisuuden lisääntyminen, tulvien hallinta, virkistyskäyttö ja metsästys. Hanke oli MMM:n rahoittama ja toteutettiin yhteistyössä Lounais-Suomen ympäristökeskuksen (LOS) kanssa.Yleissuunnittelua koskevasta ohjeistosta vastasi LOS ja tästä julkaisusta Suomen ympäristökeskus (SYKE)

Medico-legal autopsy in postoperative hemodynamic collapse following coronary artery bypass surgery

Sudden unexpected postoperative hemodynamic collapse with a high mortality develops in 1–3% of patients undergoing coronary artery bypass surgery (CABG). The contribution of surgical graft complications to this serious condition is poorly known and their demonstration at autopsy is a challenging task. Isolated CABG was performed in 8,807 patients during 1988–1999. Of the patients, 76 (0.9%) developed sudden postoperative hemodynamic collapse resulting in subsequent emergency reopening of the median sternotomy and open cardiac massage. Further emergency reoperation could be performed in 62 (82%) whereas 14 patients died prior to reoperation and a further 21 did not survive the reoperation or died a few days later. All 35 (46%) patients who did not survive were subjected to medico-legal autopsy combined with postmortem cast angiography. By combining clinical data with autopsy and angiography data, various types of graft complications were observed in 27 (36%, 1.3 per patient) of the 76 patients with hemodynamic collapse. There were no significant differences in the frequency (33 vs. 40%) or number of complicated grafts per patient (1.2 vs. 1.4) between those who survived reoperation and who did not. Autopsy detected 25 major and minor findings not diagnosed clinically. Postmortem cast angiography visualized 2 graft twists not possible to detect by autopsy dissection only. Surgical graft complications were the most frequent single cause for sudden postoperative hemodynamic collapse in CABG patients leading to a fatal outcome in almost half of the cases. Postmortem angiography improved the accuracy of autopsy diagnostics of graft complications

Arthroscopic partial meniscectomy versus placebo surgery for a degenerative meniscus tear : a 2-year follow-up of the randomised controlled trial

Objective To assess if arthroscopic partial meniscectomy (APM) is superior to placebo surgery in the treatment of patients with degenerative tear of the medial meniscus. Methods In this multicentre, randomised, participant-blinded and outcome assessor-blinded, placebo-surgery controlled trial, 146 adults, aged 35-65 years, with knee symptoms consistent with degenerative medial meniscus tear and no knee osteoarthritis were randomised to APM or placebo surgery. The primary outcome was the between-group difference in the change from baseline in the Western Ontario Meniscal Evaluation Tool (WOMET) and Lysholm knee scores and knee pain after exercise at 24 months after surgery. Secondary outcomes included the frequency of unblinding of the treatment-group allocation, participants' satisfaction, impression of change, return to normal activities, the incidence of serious adverse events and the presence of meniscal symptoms in clinical examination. Two subgroup analyses, assessing the outcome on those with mechanical symptoms and those with unstable meniscus tears, were also carried out. Results In the intention-to-treat analysis, there were no significant between-group differences in the mean changes from baseline to 24 months in WOMET score: 27.3 in the APM group as compared with 31.6 in the placebo-surgery group (between-group difference, -4.3; 95% CI, -11.3 to 2.6); Lysholm knee score: 23.1 and 26.3, respectively (-3.2; -8.9 to 2.4) or knee pain after exercise, 3.5 and 3.9, respectively (-0.4; -1.3 to 0.5). There were no statistically significant differences between the two groups in any of the secondary outcomes or within the analysed subgroups. Conclusions In this 2-year follow-up of patients without knee osteoarthritis but with symptoms of a degenerative medial meniscus tear, the outcomes after APM were no better than those after placebo surgery. No evidence could be found to support the prevailing ideas that patients with presence of mechanical symptoms or certain meniscus tear characteristics or those who have failed initial conservative treatment are more likely to benefit from APM.Peer reviewe

Sensory Appeal and Routines Beat Health Messages and Visibility Enhancements : Mixed-Methods Analysis of a Choice-Architecture Intervention in a Workplace Cafeteria

Easier recognition and enhanced visibility of healthy options supposedly increase healthy choices, but real-world evidence remains scarce. Addressing this knowledge gap, we promoted nutritionally favourable foods in a workplace cafeteria with three choice-architectural strategies—priming posters, point-of-choice nutrition labels, and improved product placement—and assessed their effects on visual attention, food choices, and food consumption. Additionally, we developed a method for analysing real-world eye-tracking data. The study followed a pretest–posttest design whereby control and intervention condition lasted five days each. We monitored visual attention (i.e., total number and duration of fixations) and food choices with eye tracking, interviewed customers about perceived influences on food choices, and measured cafeteria-level food consumption (g). Individual-level data represents 22 control and 19 intervention participants recruited at the cafeteria entrance. Cafeteria-level data represents food consumption during the trial (556/589 meals sold). Results indicated that the posters and labels captured participants’ visual attention (~13% of fixations on defined areas of interest before food choices), but the intervention had insignificant effects on visual attention to foods, on food choices, and on food consumption. Interviews revealed 17 perceived influences on food choices, the most common being sensory appeal, healthiness, and familiarity. To conclude, the intervention appeared capable of attracting visual attention, yet ineffective in increasing healthier eating. The developed method enabled a rigorous analysis of visual attention and food choices in a natural choice setting. We discuss ways to boost the impact of the intervention on behaviour, considering target groups’ motives. The work contributes with a unique, mixed-methods approach and a real-world setting that enabled a multi-dimensional effects evaluation with high external validity.publishedVersionPeer reviewe

Common Genetic Variation And Age at Onset Of Anorexia Nervosa

Background Genetics and biology may influence the age at onset of anorexia nervosa (AN). The aims of this study were to determine whether common genetic variation contributes to AN age at onset and to investigate the genetic associations between age at onset of AN and age at menarche. Methods A secondary analysis of the Psychiatric Genomics Consortium genome-wide association study (GWAS) of AN was performed which included 9,335 cases and 31,981 screened controls, all from European ancestries. We conducted GWASs of age at onset, early-onset AN (< 13 years), and typical-onset AN, and genetic correlation, genetic risk score, and Mendelian randomization analyses. Results Two loci were genome-wide significant in the typical-onset AN GWAS. Heritability estimates (SNP-h2) were 0.01-0.04 for age at onset, 0.16-0.25 for early-onset AN, and 0.17-0.25 for typical-onset AN. Early- and typical-onset AN showed distinct genetic correlation patterns with putative risk factors for AN. Specifically, early-onset AN was significantly genetically correlated with younger age at menarche, and typical-onset AN was significantly negatively genetically correlated with anthropometric traits. Genetic risk scores for age at onset and early-onset AN estimated from independent GWASs significantly predicted age at onset. Mendelian randomization analysis suggested a causal link between younger age at menarche and early-onset AN. Conclusions Our results provide evidence consistent with a common variant genetic basis for age at onset and implicate biological pathways regulating menarche and reproduction.Peer reviewe

Changes in gut bacterial populations and their translocation into liver and ascites in alcoholic liver cirrhotics

Background The liver is the first line of defence against continuously occurring influx of microbial-derived products and bacteria from the gut. Intestinal bacteria have been implicated in the pathogenesis of alcoholic liver cirrhosis. Escape of intestinal bacteria into the ascites is involved in the pathogenesis of spontaneous bacterial peritonitis, which is a common complication of liver cirrhosis. The association between faecal bacterial populations and alcoholic liver cirrhosis has not been resolved. Methods Relative ratios of major commensal bacterial communities (Bacteroides spp., Bifidobacterium spp., Clostridium leptum group, Enterobactericaea and Lactobacillus spp.) were determined in faecal samples from post mortem examinations performed on 42 males, including cirrhotic alcoholics (n = 13), non-cirrhotic alcoholics (n = 15), non-alcoholic controls (n = 14) and in 7 healthy male volunteers using real-time quantitative PCR (RT-qPCR). Translocation of bacteria into liver in the autopsy cases and into the ascites of 12 volunteers with liver cirrhosis was also studied with RT-qPCR. CD14 immunostaining was performed for the autopsy liver samples. Results Relative ratios of faecal bacteria in autopsy controls were comparable to those of healthy volunteers. Cirrhotics had in median 27 times more bacterial DNA of Enterobactericaea in faeces compared to the healthy volunteers (p = 0.011). Enterobactericaea were also the most common bacteria translocated into cirrhotic liver, although there were no statistically significant differences between the study groups. Of the ascites samples from the volunteers with liver cirrhosis, 50% contained bacterial DNA from Enterobactericaea, Clostridium leptum group or Lactobacillus spp.. The total bacterial DNA in autopsy liver was associated with the percentage of CD14 expression (p = 0.045). CD14 expression percentage in cirrhotics was significantly higher than in the autopsy controls (p = 0.004). Conclusions Our results suggest that translocation of intestinal bacteria into liver may be involved as a one factor in the pathogenesis of alcoholic liver cirrhosis.BioMed Central open acces

Shared genetic risk between eating disorder- and substance-use-related phenotypes:Evidence from genome-wide association studies

First published: 16 February 202