Identifying High-Risk Patients for Severe Pulmonary Complications after Cardiosurgical Procedures as a Target Group for Further Assessment of Lung-Protective Strategies.

OBJECTIVES: It remains unclear whether intraoperative lung-protective strategies can reduce the rate of respiratory complications after cardiac surgery, partly because low-risk patients have been studied in the past. The authors established a screening model to easily identify a high-risk group for severe pulmonary complications (ie, pneumonia or acute respiratory distress syndrome) that may be the ideal target population for the assessment of the potential benefits of such measures. DESIGN: Retrospective observational trial. SETTING: Departments of cardiac surgery and cardiac anesthesia of a university hospital. PARTICIPANTS: Consecutive patients undergoing cardiac surgery on cardiopulmonary bypass and subsequent treatment at a dedicated cardiosurgical intensive care unit between January 2019 and March 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 2,572 patients undergoing surgery, 84 (3.3%) developed pneumonia/acute respiratory distress syndrome that significantly affected the outcome (ie, longer ventilatory support [66% vs 11%], higher reintubation rate [39% vs 3%]), prolonged length of intensive care unit [33 ± 36 vs 4 ± 10 days] and hospital stay [10 ± 15 vs 6 ± 7 days], and higher in-hospital [43% vs 9%] as well as 30-day [7% vs 3%] mortality). The screening model for severe pulmonary complications included left ventricular ejection fraction <52%, EuroSCORE II (European System for Cardiac Operative Risk Evaluation II) >5.9, cardiopulmonary bypass time >123 minutes, left ventricular assist device or aortic repair surgery, and bronchodilatory therapy. A cutoff for the predicted risk of 2.5% showed optimal sensitivity and specificity, with an area under the receiver operating characteristic curve of 0.82. CONCLUSIONS: The authors suggest that future research on intraoperative lung-protective measures focuses on this high-risk population, primarily aiming to mitigate severe forms of postoperative pulmonary dysfunction associated with poor outcomes and increased resource consumption.

Identifying a target group for selenium supplementation in high-risk cardiac surgery: a secondary analysis of the SUSTAIN CSX trial.

BACKGROUND: Recent data from the randomized SUSTAIN CSX trial could not confirm clinical benefits from perioperative selenium treatment in high-risk cardiac surgery patients. Underlying reasons may involve inadequate biosynthesis of glutathione peroxidase (GPx3), which is a key mediator of selenium's antioxidant effects. This secondary analysis aimed to identify patients with an increase in GPx3 activity following selenium treatment. We hypothesize that these responders might benefit from perioperative selenium treatment. METHODS: Patients were selected based on the availability of selenium biomarker information. Four subgroups were defined according to the patient's baseline status, including those with normal kidney function, reduced kidney function, selenium deficiency, and submaximal GPx3 activity. RESULTS: Two hundred and forty-four patients were included in this analysis. Overall, higher serum concentrations of selenium, selenoprotein P (SELENOP) and GPx3 were correlated with less organ injury. GPx3 activity at baseline was predictive of 6-month survival (AUC 0.73; p = 0.03). While selenium treatment elevated serum selenium and SELENOP concentrations but not GPx3 activity in the full patient cohort, subgroup analyses revealed that GPx3 activity increased in patients with reduced kidney function, selenium deficiency and low to moderate GPx3 activity. Clinical outcomes did not vary between selenium treatment and placebo in any of these subgroups, though the study was not powered to conclusively detect differences in outcomes. CONCLUSIONS: The identification of GPx3 responders encourages further refined investigations into the treatment effects of selenium in high-risk cardiac surgery patients.

[The Role of the Percutaneous Impella Pump in Anesthesia and Intensive Care]. / Die Rolle der perkutanen Impella-Pumpe in der Anästhesie und Intensivmedizin.

The use of temporary mechanical circulatory support (tMCS) devices and in particular the increasing use of the Impella device family has gained significant interest over the last two decades. Nowadays, its use plays a well-established key role in both the treatment of cardiogenic shock, and as a preventive and protective therapeutic option during high-risk procedures in both cardiac surgery and cardiology, such as complex percutaneous interventions (protected PCI). Thus, it is not surprising that the Impella device is more and more present in the perioperative setting and especially in patients on intensive care units. Despite the numerous advantages such as cardiac resting and hemodynamic stabilization, potential adverse events exist, which may lead to severe, but preventable complications, so that adequate education, early recognition of such events and a subsequent adequate management are crucial in patients with tMCS. This article provides an overview especially for anesthesiologists and intensivists focusing on technical basics, indications and contraindications for its use with special focus on the intra- and postoperative management. Furthermore, troubleshooting for most common complications for patients on Impella support is provided.

Stroke Volume and Arterial Pressure Fluid Responsiveness in Patients With Elevated Stroke Volume Variation Undergoing Major Vascular Surgery: A Prospective Intervention Study.

OBJECTIVES: The identification of potential hemodynamic indicators to increase the predictive power of stroke-volume variation (SVV) for mean arterial pressure (MAP) and stroke volume (SV) fluid responsiveness. DESIGN: A prospective intervention study. SETTING: At a single-center university hospital. PARTICIPANTS: Nineteen patients during major vascular surgery with 125 fluid interventions. INTERVENTIONS: When SVV ≥13% occurred for >30 seconds, 250 mL of Ringer's lactate were given within 2 minutes. MEASUREMENTS AND MAIN RESULTS: Hemodynamic variables, such as pulse-pressure variation (PPV) and dynamic arterial elastance (Edyn), were measured by pulse power-wave analysis. The outcomes were MAP and SV responsiveness, defined as an increase of at least 10% of MAP and SV within 5 minutes of the fluid intervention. Of the fluid interventions, 48% were MAP-responsive, and 66% were SV-responsive. The addition of PPV and Edyn cut-off values to the SVV cut-off decreased sensitivity from 1-to-0.66 to-0.82, and concomitantly increased specificity from 0-to- 0.65-to-0.93 for the prediction of MAP and SV responsiveness in the authors' study setting. The areas under the receiver operating characteristic curves of PPV and Edyn for the prediction of MAP responsiveness were 0.79 and 0.75, respectively. The areas under the receiver operating characteristic curves for PPV and Edyn to predict SV responsiveness were 0.85 and 0.77, respectively. CONCLUSIONS: The PPV and Edyn showed good accuracy for the prediction of MAP and SV responsiveness in patients with elevated SVV during vascular surgery. Either PPV or Edyn may be used in conjunction with SVV to better predict MAP and SV fluid responsiveness in patients undergoing vascular surgery.

Initial Postoperative Hemoglobin Values Are Independently Associated With One-Year Mortality in Patients Undergoing Double-Lung Transplantation Requiring Intraoperative Transfusion.

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.

Non-pulsatile blood flow is associated with enhanced cerebrovascular carbon dioxide reactivity and an attenuated relationship between cerebral blood flow and regional brain oxygenation.

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 < 0.0001). However, the MCAv/PaCO2 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 < 0.0001). However, the relationship between ΔrSO2 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).

Evaluation of an active decision support system for hemodynamic optimization during elective major vascular surgery.

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.

Postoperative management of patients undergoing cardiac surgery in Austria : A national survey on current clinical practice in hemodynamic monitoring and postoperative management.

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.

Earplugs during the first night after cardiothoracic surgery may improve a fast-track protocol.

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.

Accuracy of Continuous Cardiac Output Measurement With the LiDCOplus System During Intra-Aortic Counterpulsation After Cardiac Surgery.

OBJECTIVE: To evaluate the effect of intra-aortic counterpulsation on precision, accuracy, and concordance of continuous pulse contour cardiac output determined using LiDCOplus (LiDCO Group, London). DESIGN: Prospective trial. SETTING: University hospital critical care unit. PARTICIPANTS: Patients with intra-aortic balloon pump support in the 1:1 mode after elective or urgent cardiac surgery. INTERVENTIONS: Lithium dilution calibrated pulse contour cardiac output was compared with pulmonary artery bolus thermodilution cardiac output during hemodynamically stable conditions in the course of standardized postoperative management. MEASUREMENTS AND MAIN RESULTS: Fifty-one paired measurements demonstrated good correlation between the 2 methods (r = 0.88, p<0.001). Mean bias was -0.14±0.81 L/min, limits of agreement 1.48 to -1.77 L/min, and percentage error 28%. Concordance between the 2 techniques regarding directional changes>±10% cardiac output was 100% (p = 0.008). Trending ability was moderate when paired cardiac output changes were assessed using linear regression, 4-quadrant table, and polar plots. When changes <±10% of the reference cardiac output were excluded, 90% of the data pairs still lay within the 30° radial limits. Optimal timing of the balloon pump was indispensable for proper determination of pulse contour cardiac output. CONCLUSIONS: Because of the LiDCOplus-specific algorithm in determining stroke volume from the arterial pulse waveform, which differs from other devices, accuracy and precision of continuous pulse contour cardiac output only are affected insignificantly by intra-aortic counterpulsation. The authors nevertheless caution that the device should be recalibrated after major hemodynamic alterations or otherwise inexplicable changes of the pulse contour cardiac output to improve trending.