Tehohoitopotilaiden neuromonitorointi

In critical illness the risk of neurological insults is high, whether because of the illness itself, or as a treatment complication. As a result, the length of hospital stay and the risk of both further morbidity and mortality are all roughly doubled. One of the major challenges is the inability to monitor a sedated, mechanically ventilated patient’s neurological symptoms during intensive care treatment, due to a lack of reliable methods. The aims of this thesis research were to identify and test potential non-invasive methods, which would be predictive of neurological outcome, showing potential as neuromonitoring methods of critical care patients unable to self-report. As a guiding theme, all tested methods could be applied to actual critical care with relative ease. Patients were included from two groups with a notably high incidence of neurological complications, namely acute liver failure patients with hepatic encephalopathy (I), and aortic surgery patients operated during hypothermic circulatory arrest (II). The first group included 20 patients, and the latter 30 patients. Late mortality and quality of life was assessed for the aortic surgery patients (III), and the postoperative development of certain blood biomarkers (IV). The tested non-invasive neuromonitoring methods included electroencephalogram (EEG) variables from frontal or fronto-temporal abbreviated monitoring, frontal near-infrared spectroscopy, transcranial Doppler ultrasound measurements of the intracranial blood flow, and finally biomarkers. The last included established biomarkers with an association with neurological complications, namely neuron-specific enolase, and protein S100β, and several interesting biomarkers normally associated with tumours and pancreatitis. Of the tested methods, the frontal EEG variables showed greatest promise, but the addition of the temporal channels did not increase sensitivity. Spectral EEG variables were predictive of the stage of hepatic encephalopathy (I), while a novel EEG variable called wavelet subband entropy was predictive of neurological outcome (I). The hemispheric asymmetry of frontal EEG was reasonably predictive of neurological outcome after aortic surgery (II). None of the other tested methods were predictive of outcome (I, II, IV), except protein S100β, which was significantly higher in the poor outcome group 48 to 72 hours after hypothermic circulatory arrest (II). The quality of life of aortic surgery patients was good after 5 to 8 years, and comparable with the general population of chronically ill patients (III). The aim of this explorative research was to identify and test non-invasive neuromonitoring methods, suitable for use in critical care. Based on the results, frontal EEG variables are promising and predict the grade of hepatic encephalopathy and neurological outcome. The other tested methods were not predictive of neurological outcome. The long-term quality of life of aortic surgery patients is very good, despite the high risk for neurological complications.Kriittisissä sairauksissa neurologisen komplikaation riski on suuri, sekä itse kriittisen sairauden että varsinaisen hoidon seurauksena. Haittatapahtuman johdosta sairaalahoidon kesto sekä sairastuvuuden ja kuolleisuuden riskit kaksinkertaistuvat. Yksi suurimmista haasteista on luotettavien menetelmien puute, joilla voitaisiin arvioida mekaanisen hengitystuen varassa olevan ja rauhoittavia lääkkeitä saavan potilaan neurologisia oireita tehohoidon aikana. Tämän väitöskirjatyön tarkoituksena oli tunnistaa ja testata lupaavia ei-kajoavia menetelmiä, jotka ennustaisivat neurologista lopputulosta, ja jotka soveltuisivat kriittisesti sairaan tehohoitopotilaan neuromonitorointiin. Kantavana teemana kaikki testatut menetelmät voitaisiin soveltaa kliiniseen työhön suhteellisen helposti. Potilaita kerättiin kahteen ryhmään, joissa neurologisten komplikaatioiden esiintyvyys on huomattavan suuri. Ensimmäinen ryhmä käsitti akuuttia maksan vajaatoimintaa ja hepaattista enkefalopatiaa sairastavat potilaat (I), toinen hypotermisen verenkierron pysäytyksen aikana rinta-aortan leikkauksen läpikäyvät potilaat (II). Ensimmäiseen ryhmään kuului 20 potilasta, jälkimmäiseen 30 potilasta. Aorttaleikatuilta potilailta arvioitiin myös elämänlaatua sekä myöhäiskuolleisuutta (III), lisäksi tiettyjen biomerkkiaineiden aorttaleikkauksen jälkeistä kehitystä ja soveltuvuutta neuromonitorointiin arvioitiin yhdessä osatyössä (IV). Tutkimuksessa arvioituihin ei-kajoaviin neuromonitorointimenetelmiin lukeutuivat otsa- ja ohimolohkon elektroenkefalografia (EEG), lähi-infrapunaspektroskopia, transkraniaalinen Doppler-ultraäänimittaus sekä verestä mitattavat biomerkkiaineet. Biomerkkiaineet kattoivat sekä vakiintuneita aivovauriota heijastavia merkkiaineita (hermostoperäinen enolaasi, proteiini S100β) että useita mielenkiintoisia merkkiaineita, jotka liittyvät kasvaintauteihin ja haimatulehdukseen. Testatuista menetelmistä otsalohkon EEG muuttujat olivat lupaavia, mutta ohimolohkon EEG lisääminen ei parantanut menetelmien herkkyyttä. EEG spektrimuuttujat ennustivat hepaattisen enkefalopatian astetta (I) luotettavasti, kun taas kokeellinen EEG-muuttuja (aalloke-alitaajuuden entropia) ennusti luotettavasti neurologista lopputulosta akuutin maksan vajaatoimintaa sairastavilla potilailla (I). Otsalohkon aivopuoliskojen EEG-rekisteröinnin hetkellinen epäsymmetria ennusti kohtalaisella tarkkuudella neurologisten päätetapahtumien esiintymisen aorttaleikatuilla potilailla (II). Muut testatut menetelmät eivät ennustaneet neurologista lopputulemaa (I, II, IV), paitsi proteiini S100β, joka oli merkittävästi korkeampi 48–72 tuntia leikkauksen jälkeen niillä potilailla, joiden neurologinen toipuminen oli huono (IV). Aorttaleikattujen potilaiden elämänlaatu oli hyvä 5–8 vuotta leikkauksen jälkeen ja verrattavissa kroonisesti sairaan väestön elämänlaatuun (III). Tämän kartoittavan tutkimuksen tarkoituksena oli tunnistaa ja testata ei-kajoavia neuromonitorointimenetelmiä, jotka soveltuvat tehohoitoon. Tulosten perusteella otsalohkon EEG-muuttujat ennustavat hepaattisen enkefalopatian astetta sekä potilaan neurologista toipumista. Muut testatut menetelmät eivät ennustaneet neurologista toipumista luotettavasti. Aorttaleikattujen potilaiden pitkäaikainen (5–8 vuoden) terveyteen liittyvä elämänlaatu on erittäin hyvä, vaikka leikkaukseen liittyy korkea aivovaurion riski

Noninvasive Neuromonitoring of Hypothermic Circulatory Arrest in Aortic Surgery

Background and Aims: Circulatory arrest carries a high risk of neurological damage, but modern monitoring methods lack reliability, and is susceptible to the generalized effects of both anesthesia and hypothermia. The objective of this prospective, explorative study was to research promising, reliable, and noninvasive methods of neuromonitoring, capable of predicting neurological outcome after hypothermic circulatory arrest. Materials and Methods: Thirty patients undergoing hypothermic circulatory arrest during surgery of the thoracic aorta were recruited in a single center and over the course of 4 years. Neuromonitoring was performed with a four-channel electroencephalogram montage and a near-infrared spectroscopy monitor. All data were tested off-line against primary neurological outcome, which was poor if the patient suffered a significant neurological complication (stroke, operative death). Results: A poor primary neurological outcome seen in 10 (33%) patients. A majority (63%) of the cases were emergency surgery, and thus, no neurological baseline evaluation was possible. The frontal hemispheric asymmetry of electroencephalogram, as measured by the brain symmetry index, predicted primary neurological outcome with a sensitivity of 79 (interquartile range; 62%-88%) and specificity of 71 (interquartile range; 61%-84%) during the first 6 h after end of circulatory arrest. Conclusion: The hemispheric asymmetry of frontal electroencephalogram is inherently resistant to generalized dampening effects and is predictive of primary neurological outcome. The brain symmetry index provides an easy-to-use, noninvasive neuromonitoring method for surgery of the thoracic aorta and postoperative intensive care.Peer reviewe

Cerebral Perfusion and Neuromonitoring during Complex Aortic Arch Surgery: A Narrative Review

: Complex ascending and aortic arch surgery requires the implementation of different cerebral protection strategies to avoid or limit the probability of intraoperative brain damage during circulatory arrest. The etiology of the damage is multifactorial, involving cerebral embolism, hypoperfusion, hypoxia and inflammatory response. These protective strategies include the use of deep or moderate hypothermia to reduce the cerebral oxygen consumption, allowing the toleration of a variable period of absence of cerebral blood flow, and the use of different cerebral perfusion techniques, both anterograde and retrograde, on top of hypothermia, to avoid any period of intraoperative brain ischemia. In this narrative review, the pathophysiology of cerebral damage during aortic surgery is described. The different options for brain protection, including hypothermia, anterograde or retrograde cerebral perfusion, are also analyzed, with a critical review of the advantages and limitations under a technical point of view. Finally, the current systems of intraoperative brain monitoring are also discussed

An investigation into the effects of commencing haemodialysis in the critically ill

<b>Introduction:</b> We have aimed to describe haemodynamic changes when haemodialysis is instituted in the critically ill. 3 hypotheses are tested: 1)The initial session is associated with cardiovascular instability, 2)The initial session is associated with more cardiovascular instability compared to subsequent sessions, and 3)Looking at unstable sessions alone, there will be a greater proportion of potentially harmful changes in the initial sessions compared to subsequent ones. <b>Methods:</b> Data was collected for 209 patients, identifying 1605 dialysis sessions. Analysis was performed on hourly records, classifying sessions as stable/unstable by a cutoff of >+/-20% change in baseline physiology (HR/MAP). Data from 3 hours prior, and 4 hours after dialysis was included, and average and minimum values derived. 3 time comparisons were made (pre-HD:during, during HD:post, pre-HD:post). Initial sessions were analysed separately from subsequent sessions to derive 2 groups. If a session was identified as being unstable, then the nature of instability was examined by recording whether changes crossed defined physiological ranges. The changes seen in unstable sessions could be described as to their effects: being harmful/potentially harmful, or beneficial/potentially beneficial. <b>Results:</b> Discarding incomplete data, 181 initial and 1382 subsequent sessions were analysed. A session was deemed to be stable if there was no significant change (>+/-20%) in the time-averaged or minimum MAP/HR across time comparisons. By this definition 85/181 initial sessions were unstable (47%, 95% CI SEM 39.8-54.2). Therefore Hypothesis 1 is accepted. This compares to 44% of subsequent sessions (95% CI 41.1-46.3). Comparing these proportions and their respective CI gives a 95% CI for the standard error of the difference of -4% to 10%. Therefore Hypothesis 2 is rejected. In initial sessions there were 92/1020 harmful changes. This gives a proportion of 9.0% (95% CI SEM 7.4-10.9). In the subsequent sessions there were 712/7248 harmful changes. This gives a proportion of 9.8% (95% CI SEM 9.1-10.5). Comparing the two unpaired proportions gives a difference of -0.08% with a 95% CI of the SE of the difference of -2.5 to +1.2. Hypothesis 3 is rejected. Fisher’s exact test gives a result of p=0.68, reinforcing the lack of significant variance. <b>Conclusions:</b> Our results reject the claims that using haemodialysis is an inherently unstable choice of therapy. Although proportionally more of the initial sessions are classed as unstable, the majority of MAP and HR changes are beneficial in nature

Risk Factors for Prolonged Mechanical Ventilation After Pulmonary Endarterectomy: 7 Years' Experience From an Experienced Hospital in China

Background: Prolonged mechanical ventilation (PMV) is common after cardiothoracic surgery, whereas the mechanical ventilation strategy after pulmonary endarterectomy (PEA) has not yet been reported. We aim to identify the incidence and risk factors for PMV and the relationship between PMV and short-term outcomes.Methods: We studied a retrospective cohort of 171 who undergoing PEA surgery from 2014 to 2020. Cox regression with restricted cubic splines was performed to identify the cutoff value for PMV. The Least absolute shrinkage and selection operator regression and logistic regressions were applied to identify risk factors for PMV. The impacts of PMV on the short-term outcomes were evaluated.Results: PMV was defined as the duration of mechanical ventilation exceeding 48 h. Independent risk factors for PMV included female sex (OR 2.911; 95% CI 1.303–6.501; P = 0.009), prolonged deep hypothermic circulatory arrest (DHCA) time (OR 1.027; 95% CI 1.002–1.053; P = 0.036), increased postoperative blood product use (OR 3.542; 95% CI 1.203–10.423; P = 0.022), elevated postoperative total bilirubin levels (OR 1.021; 95% CI 1.007–1.034; P = 0.002), increased preoperative pulmonary artery pressure (PAP) (OR 1.031; 95% CI 1.014–1.048; P < 0.001) and elongated postoperative right ventricular anteroposterior dimension (RVAD) (OR 1.119; 95% CI 1.026–1.221; P = 0.011). Patients with PMV had longer intensive care unit stays, higher incidences of postoperative complications, and higher in-hospital medical expenses.Conclusions: Female sex, prolonged DHCA time, increased postoperative blood product use, elevated postoperative total bilirubin levels, increased preoperative PAP, and elongated postoperative RVAD were independent risk factors for PMV. Identification of risk factors associated with PMV in patients undergoing PEA may facilitate timely diagnosis and re-intervention for some of these modifiable factors to decrease ventilation time and improve patient outcomes

Acute kidney injury after ascending aorta and aortic arch replacement surgery with moderate hypothermia, circulatory arrest and cardiopulmonary bypass

The correlation between deep hypothermic circulatory arrest (DHCA) and cardiopulmonary bypass (CPB) and their effect on renal function is still not clear enough. Renal failure after surgical replacement of ascending aorta in DHCA und CPB in patients due to aneurysm or calcification represents nowadays a major concern. This major study focused on the impact of DHCA and CPB on renal function in those patients. In the presented retrospective cohort study, the database for Kiel University clinic was searched for patients with aortic arch and aortic ascending replacement surgeries with HCA and CPB techniques. Between January 1, 2001, and December 31, 2017. 1359 patients were found in our database with different causes for those operations such as ascending aortic and aortic arch -aneurysm, -dissections or -calcifications, who were operated upon. The patient records were abstracted, and the data were entered into a database and then revised for accuracy by randomly checking chart data with data on the computer. Pre- and postoperative renal function are observed and documented. Acute kidney injury (AKI) was classified according to the current ‘Kidney Disease: Improving Global Outcomes’ (KDIGO} Guidelines. The potential correlation of the length of DHCA-CPBT and worsening renal function was evaluated using Spearman’s rank correlation. The data obtained from our analysis outlined the predictive role of longer moderate HCA and CPB times a for AKI. The complex multifactorial pathophysiology plays an underlying prognostic role regarding the outcome for this life-threatening complication and requires more focused clinical trials to illustrate the contradicting results from the previous analyses regarding the causing pathophysiology. In addition to that we found out that the incidence of AKI after ascending aorta and aortic arch replacement surgery using moderate HCA and CPB is approximately 15 %. And those patients with Postopertaitve AKI have an increase in the mortaliy rate by more than 6 times and 3 times longer ICU sta

Akute postoperative Verwirrtheit nach kardiochirurgischen Eingriffen

Hintergrund - Das postoperative Verwirrtheitssyndrom stellt eine ernstzunehmende Komplikation nach kardiochirurgischen Eingriffen dar. Welche pflegerische Intervention einen positiven Einfluss auf die Inzidenz als auch auf den Krankheitsverlauf hat, ist unbestimmt. Methoden - Mittels systematischer Literaturanalyse wurden relevante Publikationen in den Literaturdatenbanken MEDLINE, EMBASE, CINAHL, PUBMED, COCHRANE, CENTRAL und COCHRANE CDSR unter Anwendung der Suchbegriffe „delirium“, „dementia“, „amnestic“, „cognitive disorders“ und „cardiac surgery“ identifiziert. Studiendesign, Patientenzahl, Patientengeschlecht, Patientenaltersgruppe, Erkrankungsgruppe, Gesamtmortalität, Akutmortalität, Dauer des Intensivaufenthaltes in Tagen, Dauer des Spitalsaufenthaltes in Tagen, Spitalsmortalität, 30-Tage Mortalität und die 1-Jahresmortalität wurden für die Bewertung der Evidenzlage herangezogen. Ergebnisse - Aus 1113 Literaturzitaten konnte nur eine Publikation mit insgesamt 40 Patienten als potentiell relevant für die gewählten Studienendpunkte vorab identifiziert werden. Es zeigte sich jedoch, dass diese Studie von methodologischer Seite den Qualitätsansprüchen nicht gerecht werden konnte. Interpretation - Eine Empfehlung einer spezifischen pflegerischen Intervention kann aufgrund der mangelnden Studienlage gemäß der Evidence-based Nursing Kriterien nicht gegeben werden. Die primäre Auswahl beruht daher weiterhin auf der Erfahrung der einzelnen Pflegefachperson (Expertenmeinung Evidenzstufe V bis unbestimmt). Methodologisch einwandfreie, randomisiert kontrollierte Studien wären in Zukunft somit wünschenswert.Background - The postoperative confusion syndrome remains a threatening complication following open cardiac surgery. Which nursing intervention may decrease incidence or ameliorate disease course, remains undetermined. Methods - We identified relevant literature via a systematic review of the databases MEDLINE, EMBASE, CINAHL, PUBMED, COCHRANE, CENTRAL and COCHRANE CDSR using the search terms "Delirium", "Dementia", "Amnestic", "Cognitive Disorders" and "Cardiac Surgery". We abstracted the study design, sample size, patient gender, patient age, disease group, all-cause mortality, acute mortality, duration of ICU stay in days, duration of hospital stay in days, hospital mortality, 30-day mortality and 1-year mortality. Results - Out of 1113 potential hints of the primary search, we identified only a single study relevant for the chosen endpoints. Distinct analysis however revealed a sub-standard methodology according to current EBN-criteria. Interpretation - A recommendation of a specific nursing intervention in event of a postoperative confusion syndrome following cardiac surgery according to Evidence Based Nursing criteria cannot be given due to lack of evidence. The primary choice therefor still relies on the experience of individual nurse (expert opinion evidence level V to indefinite). Methodologically correct, randomized controlled trials would therefore be desirable in the near future

Impact of peak intraoperative lactate levels on post-operative outcomes in congenital cardiac surgery

Published Thesi

Glucometer accuracy and implications for clinical studies

1-pag

Mannose binding lectin deficiency attenuates neurobehavioral deficits following experimental traumatic brain injury

Introduction: Mannose binding lectin (MBL) is the activator of the lectin complement pathway. After cerebral ischemia it has been shown that MBL could be a mediator of secondary brain damage, in contrast after traumatic brain injury (TBI) there are data suggesting that it could be linked to neuroprotection. We tested the hypothesis that MBL is involved in the pathophysiology of TBI. We 1) characterized the temporal activation of MBL and 2) the effects of its inhibition in a model of experimental TBI. Methods: 1) Male C57/Bl6 mice were subjected to intraperitoneal anesthesia (Pentobarbital, 65 mg/kg) followed by the controlled cortical impact brain injury model of experimental TBI (injury parameters: velocity of 5 meter/second and 1 mm depth of deformation). MBL immunostaining was evaluated at various time points after TBI: 30 minutes, 1, 6, 12, 24, 48, 96 hours and 1 week using anti MBL-A and MBL-C antibodies (n=3). 2) The effects of MBL inhibition were evaluated by comparing functional and histologic outcomes in C57/Bl6 mice (WT) and in MBL knock-out (-/-) mice. Functional outcome was tested using the Composite Neuroscore and Beam Walk test weekly up to 4 weeks postinjury (n = 11). Histologic outcome was evaluated by calculating the contusion volume at 4 weeks postinjury (n = 6). Sham-operated mice received identical anesthesia without brain injury. Results: We observed a robust MBL positive immunostaining in the injured cerebral cortex starting at 30 minutes postinjury and up to 1 week, suggestive of an activation of this pathway following TBI. MBL was observed both at endothelial and tissue level. Consistently, injured WT and MBL (-/-) mice showed neurological motor deficits up to 4 weeks postinjury when compared to their sham controls. Notably, MBL (-/-) mice showed attenuated behavioral deficits when compared to their WT counterpart at 2-4 weeks postinjury (p < 0.01 for both Neuroscore and Beam Walk test). In contrast we observed similar contusion volumes at 4 weeks postinjury (WT = 15.6 \ub1 3.2 cm3 and MBL KO = 13.9 \ub1 3.2 cm3, p = 0.3). Conclusions: We observed that 1) MBL deposition and/or synthesis is increased following TBI; 2) MBL deficiency is associated with functional neuroprotection, suggesting that MBL modulation might be a potential therapeutic target after TBI