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Background Systemic blood flow in patients on extracorporeal assist devices is frequently not or only minimally pulsatile. Loss of pulsatile brain perfusion, however, has been implicated in neurological complications. Furthermore, the adverse effects of absent pulsatility on the cerebral microcirculation are modulated similarly as CO2 vasoreactivity in resistance vessels. During support with an extracorporeal assist device swings in arterial carbon dioxide partial pressures (PaCO2) that determine cerebral oxygen delivery are not uncommon—especially when CO2 is eliminated by the respirator as well as via the gas exchanger of an extracorporeal membrane oxygenation machine. We, therefore, investigated whether non-pulsatile flow affects cerebrovascular CO2 reactivity (CVR) and regional brain oxygenation (rSO2). Methods In this prospective, single-centre case-control trial, we studied 32 patients undergoing elective cardiac surgery. Blood flow velocity in the middle cerebral artery (MCAv) as well as rSO2 was determined during step changes of PaCO2 between 30, 40, and 50 mmHg. Measurements were conducted on cardiopulmonary bypass during non-pulsatile and postoperatively under pulsatile blood flow at comparable test conditions. Corresponding changes of CVR and concomitant rSO2 alterations were determined for each flow mode. Each patient served as her own control. Results MCAv was generally lower during hypocapnia than during normocapnia and hypercapnia (p 2 slope during non-pulsatile flow was 14.4 cm/s/mmHg [CI 11.8–16.9] and 10.4 cm/s/mmHg [CI 7.9–13.0] after return of pulsatility (p = 0.03). During hypocapnia, non-pulsatile CVR (4.3 ± 1.7%/mmHg) was higher than pulsatile CVR (3.1 ± 1.3%/mmHg, p = 0.01). Independent of the flow mode, we observed a decline in rSO2 during hypocapnia and a corresponding rise during hypercapnia (p 2 and ΔMCAv was less pronounced during non-pulsatile flow. Conclusions Non-pulsatile perfusion is associated with enhanced cerebrovascular CVR resulting in greater relative decreases of cerebral blood flow during hypocapnia. Heterogenic microvascular perfusion may account for the attenuated ΔrSO2/ΔMCAv slope. Potential hazards related to this altered regulation of cerebral perfusion still need to be assessed. Trial registration The study was retrospectively registered on October 30, 2018, with Clinical Trial.gov (NCT03732651).

Risk factors for early bleeding complications after lung transplantation are not well described. Our aim was to evaluate coagulation test results and the use of extracorporeal membrane oxygenation as risk factors for bleeding after lung transplantation. We analyzed a single-center cohort of bilateral lung transplants between January 2009 and August 2015. Predictors of severe postoperative bleeding (bleeding requiring reoperation within 48 h of transplantation) were assessed using multivariable logistic regression. The effect of bleeding on survival was assessed using a Cox proportional-hazards model. Twenty-nine (4.5%) of 641 patients experienced severe postoperative bleeding. Postoperative fibrinogen levels (OR = 0.99, 95% CI 0.98-0.995, P = 0.001; per mg/dl increase) and pre- and postoperative use of extracorporeal membrane oxygenation (OR = 14.41% 95% CI 5.4-40.19, P < 0.001 and OR = 4.25, 95% CI 1.0-11.09, P = 0.002, respectively) were associated with an increased risk of severe postoperative bleeding. Severe postoperative bleeding was associated with decreased survival within 60 days after transplantation (adjusted HR = 5.73, 95% CI 2.52-13.02, P < 0.001). Low postoperative fibrinogen levels, and pre- and postoperative use of extracorporeal membrane oxygenation were risk factors for bleeding after lung transplantation.

Objective To evaluate the association of postoperative hemoglobin values and mortality in patients undergoing double- lung transplantation with intraoperative transfusion. Design Retrospective cohort study. Setting University hospital. Participants Adult patients who underwent double-lung transplantation at the authors’ institution, with intraoperative transfusion of packed red blood cells between 2009 and 2015. Interventions None. Measurements and Main Results Intraoperative transfusion requirements and general characteristics of 554 patients were collected. A generalized additive model, controlling for postoperative hemoglobin levels, number of transfused units of packed red blood cells, perioperative change in hemoglobin levels, disease leading to lung transplantation, and postoperative extracorporeal membrane oxygenation, was created to predict one-year mortality. A postoperative hemoglobin level of 11.3 g/dL was calculated as an optimal cutoff point. The patients were stratified according to this level. The end -point was all-cause one-year mortality after double-lung transplantation, assessed using the Kaplan-Meier analysis with log-rank test. All-cause mortality of the 554 patients was 17%. Postoperatively, 171 patients (31%) were categorized as being below the cutoff point. Improved survival was observed in the group with higher postoperative hemoglobin values (p = 0.002). Conclusion Lower postoperative hemoglobin levels in double-lung transplantation recipients were associated with increased mortality during the first year after surgery. Confirmation of these findings in additional investigations could alter patient blood management for double-lung transplantation.

Regional cerebral oxygen saturation (rSO2) can be measured non-invasively even at no- or low-flow states. It thus allows assessment of brain oxygenation during CPR. Certain rSO2 values had been associated with return of spontaneous circulation (ROSC) and neurological outcome in the past. Clear-cut thresholds for the prediction of beneficial outcome, however, are still lacking.We conducted a database search to extract all available investigations on rSO2 measurement during CPR. Mean, median, and ΔrSO2 values were either taken from the studies or calculated. Thresholds for the outcome "ROSC" and "neurological outcome" were sought.We retrieved 26 publications for the final review. The averaged mean rSO2 for patients achieving ROSC was 41 ± 12% vs. 30 ± 12% for non-ROSC (p = .009). ROSC was not observed when mean rSO2 remained26%. In ROSC patients, ΔrSO2 was 22 ± 16% vs. 7 ± 10% in non-ROSC patients (p = .009). A rSO2 threshold of 36% predicted ROSC with a sensitivity of 67% and specificity of 69% while ΔrSO2 of 7% showed a sensitivity of 100% and a specificity of 86% (AUC = 0.733 and 0.893, respectively). Mean rSO2 of 47 ± 11% was associated with favourable and 38 ± 12% with poor neurological outcome. There was, however, a great overlap between groups due to scarce data.Higher rSO2 consistently correlated with increased rates of ROSC. The discriminatory power of rSO2 to prognosticate favourable neurological outcome remains unclear. Measuring rSO2 during CPR could potentially facilitate clinical decision-making.

Background Active decision support systems implementing goal directed therapy may be an approach to reduce disparities in outcome between different health care providers. We assessed feasibility of and adherence to an active decision support system (ADSS) comprising fluids, vasopressors, and dobutamine to optimize hemodynamics during high-risk vascular surgery. Methods In this prospective observational trial a closed-loop goal-directed therapy protocol, employing the minimally-invasive LiDCOrapid device, was used to actively provide advice to the anesthesiologist during surgery. All given suggestions and all interventions were recorded. Every intervention without or against the given advice had to be justified. The primary outcome parameters were the number of interventions done according to the ADSS and its duration of use. Reasons for non-compliance served to describe its limitations. Results The active decision support system was employed in 32 patients for 137 hours. Median (IQR) use of the ADSS as percentage of surgery time was 100% (94-100%) with 743 interventions being executed. 634 interventions were done according to ADSS proposals. Reasons to act against or without advice were: hemodynamic instability (6%), foreseeing a surgical event (2%), medical reasons (2%), awaiting hemodynamic improvement (1%) and orders by senior physician or surgeons (1%). In five patients the anesthesiologist decided to modify intervention thresholds of the underlying protocol. Conclusions High rates of compliance underline clinical acceptability and feasibility of this ADSS during vascular surgery. It may therefore facilitate the work of anesthesiologists and reduce disparities in patient outcomes due to different healthcare providers. Particularly, rapidly developing hemodynamic perturbances as well as co-factors the ADSS as of now does not anticipate are current limitations. These findings may serve to further improve this stand-alone real-time ADSS.

Summary Background No data are currently available regarding the current clinical practice in postoperative care of cardiac surgical patients in Austria. Objective The study investigated the current intensive care management concerning hemodynamic monitoring and strategies to treat common perioperative disorders of patients after cardiac surgery in Austria. Methods A survey consisting of 31 questions was sent to intensivists at all 9 hospitals offering cardiac surgery in Austria. Results The response rate was 100%. The mean number of procedures on cardiopulmonary bypass per centre was 722 ± 223. In the majority of cases postoperative critical care is performed by anesthesiologists. Blood gas analysis, pulse oximetry, electrocardiogram, temperature, central venous pressure, arterial pressure and hourly urine output are de facto standard monitoring in all centers. Transesophageal echocardiography is available in all centers and is frequently used. Crystalloids are the first choice for volume replacement, whereas levosimendan and adrenaline are employed for the treatment of low cardiac output syndrome. Conclusions This study provides insights into the current state of postoperative management of cardiac surgical patients in Austria. Standard monitoring as proposed by international guidelines is well established in Austrian intensive care units. Echocardiography is widely seen as a very important tool in the postoperative care of cardiac surgical patients. Knowledge about the status quo of postoperative intensive care management of cardiac surgical patients enables further development of patient care. Electronic supplementary material The online version of this article (10.1007/s00508-018-1403-3) contains supplementary material, which is available to authorized users.

BACKGROUND Sleep deprivation after major surgery is common and associated with worse outcome. Noise is one important reason for sleep fragmentation, which contributes to enhanced morbidity. The purpose of this work was to evaluate the impact of earplugs on patients' sleep quality during their first night after cardiothoracic surgery to eventually improve an existing fast-track concept. METHODS Sixty-three patients undergoing cardiothoracic surgery eligible for a postoperative fast-track regimen on our cardiothoracic post anesthesia care unit (C-PACU) were prospectively included. They were randomized to either sleep with or without earplugs. Quality of sleep was measured using questionnaires for patients and nurses. Required pain medications, pain intensity, and length of hospital stay were secondary outcome variables. RESULTS Twenty-seven patients were randomized to the intervention group (earplugs) and 36 to the control group. Mean (SD) age was 61 (12) years. Self-reported quality of sleep was better in the intervention group (median, IQR [range]: 3, 2-4 [1-5] vs. 4, 3-5 [1-5]; scale: 1, "excellent," to 5, "very poor"; P=0.025). Patients of the intervention group also experienced less severe pain (P=0.047) despite similar dosages of administered analgesics and expressed improved satisfaction regarding their C-PACU stay (P=0.032). CONCLUSIONS Implementation of the use of earplugs in a fast-track concept following cardiothoracic surgery is efficient and easy. Earplugs improved the quality of sleep as well as patient satisfaction and attenuated pain intensity. They may thereby contribute to a faster recovery, less morbidity, and reduced costs.

Introduction Non-pulsatile blood flow has been associated with altered microcirculatory perfusion. Soon after loss of pulsatility a marked heterogenous flow profile in the very small vessels ensues that is coupled with impaired oxygen extraction [1]. We investigated if changes in cerebral blood flow during non-pulsatile perfusion would affect brain tissue oxygenation assessed by near-infrared spectroscopy. Methods After approval by the local ethics committee thirty-two patients were included in this trial. They were studied during general anaesthesia, and stable hemodynamic conditions. Cerebral blood flow velocity in the middle cerebral artery was measured during non-pulsatile flow in the course of cardiac surgery on total extracorporeal bypass and again postoperatively on the intensive care unit during pulsatile flow. We modified cerebral blood flow by changing arterial partial pressures of carbon dioxide between 30, 40 and 50 mmHg. This was conducted either by a change of sweep gas flow at the heart lung machine or by changing respiratory rate at the respirator. In addition to flow measurements patients' regional brain oxygenation was determined. Relative changes in blood flow velocity were plotted against relative changes in regional brain saturation for both flow conditions and compared using Pearson's correlation. A p-value Results Absolute cerebral blood flow velocity was slightly higher during non-pulsatile flow when serum hemoglobin was diluted. Relative changes in cerebral blood flow velocity and regional brain oxygenation were tightly coupled independent of the flow condition. R-values for non-pulsatile and pulsatile blood flow were 0.724 and 0.796, respectively. However, during non-pulsatile flow the slope of the regression line was less steep as compared with pulsatile flow (P Discussion Despite greater cerebral perfusion during hypercapnia and non-pulsatile flow there was no equivalent rise in cerebral oxygenation. Assuming similar cerebral oxygen delivery this finding could be explained by impaired brain oxygen extraction in the high flow range while partial pressure of carbon dioxide was elevated. In contrast, during hypocapnia, when cerebral blood flow was decreased to a greater extent as during pulsatile flow, the concomitant desaturation was less pronounced. Both findings are in line with shunting on the microcirculatory level, whereby hyperperfused vessels coexist with vessels lacking adequate flow. These findings substantiate that loss of pulsatility seems to negatively affect nutritive tissue perfusion. Raised neurological morbidity in patients supported with non-pulsatile extracorporeal cardiac assist devices could potentially be attributable to the observed perfusion deficit [2].