Predictors of Nocturnal Hypoxemic Burden in Patients Undergoing Elective Coronary Artery Bypass Grafting Surgery.

Background: Nocturnal hypoxemia has been linked to increased cardiovascular morbidity and mortality. Several common diseases, such as sleep-disordered breathing (SDB), heart failure (HF), obesity, and pulmonary disease, coincide with an elevated nocturnal hypoxemic burden with and without repetitive desaturations. Research question: This study aimed to evaluate the association of relevant common diseases with distinctive metrics of nocturnal hypoxemic burden with and without repetitive desaturations in patients undergoing coronary artery bypass grafting surgery. Study design and methods: In this subanalysis of the prospective observational study, CONSIDER-AF (NCT02877745) portable SDB monitoring was performed on 429 patients with severe coronary artery disease the night before cardiac surgery. Pulse oximetry was used to determine nocturnal hypoxemic burden, as defined by total recording time spent with oxygen saturation levels < 90% (T90). T90 was further characterized as T90 due to intermittent hypoxemia (T90desaturation) and T90 due to nonspecific and noncyclic SpO2-drifts (T90non-specific). Results: Multivariable linear regression analysis identified SDB (apnea-hypopnea-index ≥ 15/h; B [95% CI]: 6.5 [0.4; 12.5], p = 0.036), obesity (8.2 [2.5; 13.9], p = 0.005), and mild-to-moderate chronic obstructive pulmonary disease (COPD, 16.7 [8.5; 25.0], p < 0.001) as significant predictors of an increased nocturnal hypoxemic burden. Diseases such as SDB, obesity and HF were significantly associated with elevated T90desaturation. In contrast, obesity and mild-to-moderate COPD were significant modulators of T90non-specific. Interpretation: SDB and leading causes for SDB, such as obesity and HF, are associated with an increased nocturnal hypoxemic burden with repetitive desaturations. Potential causes for hypoventilation syndromes, such as obesity and mild-to-moderate COPD, are linked to an increased hypoxemic burden without repetitive desaturations. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT02877745.

Restoration of von Willebrand factor after transcatheter aortic valve replacement-A possible cause for posttranscatheter aortic valve replacement thrombocytopenia?

OBJECTIVES: The aim of the current study was to analyze the clinical and procedural predictors of thrombocytopenia and the relationship between the decrease in platelet count (DPC) and change in vWF function (ΔvWF) after transcatheter aortic valve replacement (TAVR). BACKGROUND: TAVR often causes temporary thrombocytopenia. At the same time, TAVR leads to a restoration of von Willebrand factor (vWF) function. METHODS: One hundred and forty-one patients with severe aortic stenosis undergoing TAVR were included in the study. Platelet count and vWF function (vWF:Ac/Ag ratio) were assessed at baseline and 6 h after TAVR. Thrombocytopenia was defined as platelet count <150/nL. RESULTS: Median platelet count at baseline was 214/nL (interquartile range [IQR]: 176-261) and decreased significantly to 184/nL (IQR: 145-222) 6 h after TAVR. The number of patients with thrombocytopenia increased from 12.8% at baseline to 29.1% after 6 h. DPC 6 h after TAVR showed a significant correlation with ΔvWF (r = - 0.254, p = 0.002). Patients with DPC > 20% had significantly higher ΔvWF (10.9% vs. 6.5%, p = 0.021). Obese patients showed a significantly lower DPC (11.8% vs. 19.9%, p = 0.001). In multivariate analysis, ΔvWF 6 h after TAVR was the only significant predictor for DPC > 20% (p = 0.017). CONCLUSIONS: The restoration of vWF after TAVR is a significant predictor for DPC after TAVR. An increased platelet consumption due to vWF restoration could play a key role in the development of thrombocytopenia after TAVR.

Intraoperative suggestions to prevent postoperative delirium in patients undergoing transaortic valvular replacement: a randomized placebo-controlled trial.

BACKGROUND: Postoperative delirium (POD) is a serious complication following anaesthesia and surgery and significantly influences postoperative outcome especially in the elderly population. Intraoperative music and positive suggestions influence postoperative outcomes by attenuating analgesic demand and increasing patient satisfaction. AIMS: Here, we examined the effect of intraoperative music and positive suggestions on the development of POD in aged patients undergoing transcatheter aortic valve replacement (TAVR) procedure under general anaesthesia. METHODS: For this randomized placebo-controlled study, eligible patients without cognitive deficit, indicated by a MMSE < 10 points, were anesthetized using remifentanil and sevoflurane. Anaesthetic depth was guide with bispectral index. An audiotape with positive suggestions was applied from a MP3 player via headphones. POD, pain and PONV was assessed. CAM-ICU and Nu-DESC were done twice daily for the first 5 days. RESULTS: Of 140 patients 118 patients could be analysed (57 male, 80.6 ± 5.1 years). POD was diagnosed in 16 patients (12.7%). POD was significantly more often observed in male (12, 21.1%) than in female (4, 6.6%, p = 0.02) and in patients with a low MMSE (23.6 ± 4.5 vs. 26.8 ± 2.8, p = 0.001). Anaesthetic depth did not influence the incidence of POD. Intraoperative music and suggestions did not affect the rate of POD, pain, analgesic requirement or PONV. DISCUSSION: In patients undergoing TAVR male sex and low MMSE scoring are associated with an increase in POD. CONCLUSIONS: Intraoperative music and positive suggestions do not influence the incidence of POD in this patient group. STUDY REGISTRATION: DRKS: 00024444, start of registration: 4.02.202, final registration: 17.09.2021.

The impact of bicuspid aortic valve morphology on von Willebrand factor function in patients with severe aortic stenosis and its change after TAVI.

BACKGROUND: Aortic stenosis (AS) can cause acquired von Willebrand syndrome (AVWS) and valve replacement has been shown to lead to von Willebrand factor (vWF) recovery. The aim of the current study was to investigate the prevalence of AVWS in different severe AS phenotypes and its course after transcatheter aortic valve implantation (TAVI). METHODS: 143 patients with severe AS undergoing TAVI were included in the study. vWF function was assessed at baseline, 6 and 24 h after TAVI. AVWS was defined as a reduced vWF:Ac/Ag ratio ≤ 0.7. Phenotypes were classified by tricuspid (TAV) and bicuspid (BAV) valve morphology, mean transvalvular gradient (Pmean), stroke volume index (SVI), ejection fraction (EF) and indexed effective orifice area (iEOA). RESULTS: AVWS was present in 36 (25.2%) patients before TAVI. vWF:Ac/Ag ratio was significantly lower in high gradient compared to low-gradient severe AS [0.78 (IQR 0.67-0.86) vs. 0.83 (IQR 0.74-0.93), p < 0.05] and in patients with BAV compared to TAV [0.70 (IQR 0.63-0.78) vs. 0.81 (IQR 0.71-0.89), p < 0.05]. Normalization of vWF:Ac/Ag ratio was achieved in 61% patients 24 h after TAVI. As in the overall study cohort, vWF:Ac/Ag ratio increased significantly in all severe AS subgroups 6 h after TAVI (each p < 0.05). Regarding binary logistic regression analysis, BAV was the only significant predictor for AVWS. CONCLUSIONS: BAV morphology is a strong predictor for AVWS in severe AS. TAVI restores vWF function in most patients with severe AS independently of AS phenotype and valve morphology.

[Modern Perioperative Care Concepts in Thoracic Surgery: Enhanced Recovery After Thoracic Surgery (ERATS)]. / Moderne perioperative Versorgungskonzepte in der Thoraxchirurgie: Enhanced Recovery After Thoracic Surgery (ERATS).

In modern perioperative care concepts, multimodal ERAS (Enhanced Recovery After Surgery) is a multimodal perioperative treatment concept for improving postoperative recovery of surgical patients after an operation. This is managed by the so-called ERAS Society and through which hospitals can also be officially certified. The focus of the ERAS concept is on uniform patient care from admission to discharge, with the aim of improving perioperative processes by implementing evidence-based protocols involving a multidisciplinary treatment team. In 2019, ERAS guidelines were published for the first time by the European Society of Thoracic Surgery (ESTS), in cooperation with the ERAS Society, for specific lung resection procedures, and these identified a total of 45 graduated recommendations or Enhanced Recovery Pathways (ERP). The implementation of ERAS concepts in thoracic surgery (ERATS = Enhanced Recovery After Thoracic Surgery) is intended to establish standardised perioperative procedures based on study results and/or expert recommendations. These recommendations take into account organisational aspects as well as thoracic surgical and anaesthesiological procedures, with the overriding goal of creating a structured treatment plan tailored to the patient. All these measures should result in a multimodal overall concept, which should primarily lead to an improved outcome after elective thoracic surgery and secondarily to shorter hospital stays with correspondingly lower costs.This review article describes basic ERAS principles and provides a compact presentation of the most important European ERAS recommendations from the authors' point of view, together with typical obstacles to the implementation of the corresponding ERATS program in German thoracic surgery.

Evaluation of comprehensiveness and reliability of electronic health records concerning resuscitation efforts within academic intensive care units: a retrospective chart analysis.

BACKGROUND: According to the literature, the validity and reliability of medical documentation concerning episodes of cardiopulmonary resuscitation (CPR) is suboptimal. However, little is known about documentation quality of CPR efforts during intensive care unit (ICU) stays in electronic patient data management systems (PDMS). This study analyses the reliability of CPR-related medical documentation within the ICU PDMS. METHODS: In a retrospective chart analysis, PDMS records of three ICUs of a single university hospital were searched over 5 y for CPR check marks. Respective datasets were analyzed concerning data completeness and data consistency by comparing the content of three documentation forms (physicians' log, nurses' log, and CPR incident form), as well as physiological and therapeutic information of individual cases, for missing data and plausibility of CPR starting time and duration. To compare data reliability and completeness, a quantitative measure, the Consentaneity Index (CI), is proposed. RESULTS: One hundred sixty-five datasets were included into the study. In 9% (n = 15) of cases, there was neither information on the time points of CPR initiation nor on CPR duration available in any data source. Data on CPR starting time and duration were available from at least two data sources in individual cases in 54% (n = 90) and 45% (n = 74), respectively. In these cases, the specifications of CPR starting time did differ by a median ± interquartile range of 10.0 ± 18.5 min, CPR duration by 5.0 ± 17.3 min. The CI as a marker of data reliability revealed a low consistency of CPR documentation in most cases, with more favorable results, if the time interval between the CPR episode and the time of documentation was short. CONCLUSIONS: This study reveals relevant proportions of missing and inconsistent data in electronic CPR documentation in the ICU setting. The CI is suggested as a tool for documentation quality analysis and monitoring of improvements.

Central Sleep Apnea Predicts Pulmonary Complications After Cardiac Surgery.

BACKGROUND: Postoperative major pulmonary complications (MPCs) continue to be leading causes of increased morbidity and death after cardiac surgery. Although various risk factors have been identified, reports on the association between sleep-disordered breathing (SDB) and postoperative MPCs remain inconclusive. RESEARCH QUESTION: What is the incidence of the composite end point postoperative MPCs? What are predictors for postoperative MPCs in patients without SDB, with OSA, and with central sleep apnea (CSA) who undergo cardiac surgery? STUDY DESIGN AND METHODS: In this subanalysis of the ongoing prospective observational study "Impact of Sleep-disordered breathing on Atrial Fibrillation and Perioperative complications in Patients undergoing Coronary Artery Bypass grafting Surgery (CONSIDER AF)," preoperative risk factors for postoperative MPCs were examined in 250 patients who underwent cardiac surgery. Postoperative MPCs (including respiratory failure, acute respiratory distress syndrome, pneumonia, or pulmonary embolism) were registered prospectively within the first seven postoperative days. Presence and type of SDB were assessed the night prior to surgery with the use of portable SDB-monitoring. RESULTS: Patients with SDB experienced significantly more often postoperative MPCs than patients without SDB (24% vs 7%; P < .001). Multivariable logistic regression analysis showed that CSA (OR, 4.68 [95% CI, 1.78-12.26]; P = .002), heart failure (OR, 2.65 [95% CI, 1.11-6.31]; P = .028), and a history of transient ischemic attack or stroke (OR, 2.73 [95% CI, 1.07-6.94]; P = .035) were associated significantly with postoperative MPCs. Compared with patients without MPCs, those with postoperative MPCs had a significantly longer hospital stay (median days, 9 [25th/75th percentile, 7/13] vs 19 [25th/75th percentile, 11/38]; P < .001). INTERPRETATION: Among established risk factors for postoperative MPCs, CSA, heart failure, and history of transient ischemic attack or stroke were associated significantly with postoperative MPCs. Our findings contribute to the identification of patients who are at high-risk for postoperative MPCs. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02877745.

Is there really a benefit of using minimized cardiopulmonary bypass in CABG? A retrospective propensity score-matched study with 5000 cases.

The concept of minimized cardiopulmonary bypass targets at reduction of adverse effects triggered by extracorporeal circulation. In this study, benefits of minimized bypass in CABG were evaluated under particular consideration of patient body mass index and surgeon impact. From 2004 to 2014, 5164 patients underwent coronary bypass surgery (CABG). Conventional cardiopulmonary bypass (CCPB) was used in 2376 patients, minimized cardiopulmonary bypass (MCPB) in 2788 cases. Multivariate regression models were used in the entire cohort and in a propensity score-matched subgroup after expert CABG to figure out clinical differences such as mortality, postoperative renal function, and thromboembolic events. Overall mortality was 1.5% (n = 41) in the MCPB group and 3.5% (n = 82) in CCPB patients (p < 0.001). Postoperative renal failure and hemodialysis occurred in 2.6% (n = 72/MCPB) vs. 5.3% (n = 122/CCPB (p < 0.001). Multivariable regression revealed use of CCPB as risk factor for increased mortality (OR 2.01, p = 0.001), renal failure (OR 1.79, p < 0.001), and myocardial infarction (OR 1.98, p < 0.001) comparable to risk factors such as preoperative ventilation (OR 2.26, p = 0.048), diabetes mellitus (OR 1.68, p = 0.001), and cardiogenic shock (OR 3.81, p = 0.002). Body mass index had no effect on the analyzed outcome parameters (OR 0.92, p = 0.002). Propensity score-matching analysis of an expert CABG subgroup revealed CCPB as risk factor for mortality (OR 2.26, p = 0.004) and postoperative hemodialysis (OR 1.74, p = 0.017). Compared to conventional circuits, minimized bypass use in CABG is associated with lower mortality and less postoperative renal failure. A high body mass index is feasible and not a risk factor for MCPB surgery.

Predictors of delirium after cardiac surgery in patients with sleep disordered breathing.

INTRODUCTION: Delirium ranks among the most common complications after cardiac surgery. Although various risk factors have been identified, the association between sleep disordered breathing (SDB) and delirium has barely been examined so far. Here, our objectives were to determine the incidence of post-operative delirium and to identify the risk factors for delirium in patients with and without SDB. METHODS: This subanalysis of the ongoing prospective observational study CONSIDER-AF (ClinicalTrials.gov identifier NCT02877745) examined risk factors for delirium in 141 patients undergoing cardiac surgery. The presence and type of SDB were assessed with a portable SDB monitor the night before surgery. Delirium was prospectively assessed with the validated Confusion Assessment Method for the Intensive Care Unit on the day of extubation and for a maximum of 3 days. RESULTS: Delirium was diagnosed in 23% of patients: in 16% of patients without SDB, in 13% with obstructive sleep apnoea and in 49% with central sleep apnoea. Multivariable logistic regression analysis showed that delirium was independently associated with age ≥70 years (OR 5.63, 95% CI 1.79-17.68; p=0.003), central sleep apnoea (OR 4.99, 95% CI 1.41-17.69; p=0.013) and heart failure (OR 3.3, 95% CI 1.06-10.35; p=0.039). Length of hospital stay and time spent in the intensive care unit/intermediate care setting were significantly longer for patients with delirium. CONCLUSIONS: Among the established risk factors for delirium, central sleep apnoea was independently associated with delirium. Our findings contribute to identifying patients at high risk of developing post-operative delirium who may benefit from intensified delirium prevention strategies.

Conventional or minimized cardiopulmonary bypass support during coronary artery bypass grafting? - An analysis by means of perfusion and body mass index.

The use of minimized cardiopulmonary bypass support to reduce the side effects of extracorporeal circulation is still contradictorily discussed. This study compares perfusion operated by conventional (CCPB) and minimized (MCPB) cardiopulmonary bypass support during coronary artery bypass grafting (CABG). This study includes the data of 5164 patients treated at our department between 2004 and 2014. Tissue perfusion during cardiopulmonary bypass support and cardiac arrest was assessed by means of body mass index, hemodilution, blood pressure with corresponding pump flow and venous oxygen saturation, serum lactate, and serum pH. Hemodilution was more pronounced after CCPB: hemoglobin had dropped to 4.47 ± 0.142 g/dL after CCPB and to 2.77 ± 0.148 g/dL after MCPB (P = 0.0022). Despite the higher pump flow in conventional circuits (4.86-4.95 L/min vs. 4.1-4.18 L/min), mean blood pressure was higher during minimized bypass support (53 ± 10 vs. 56 ± 13 mm Hg [aortic clamping], 57 ± 9 vs. 61 ± 12 mm Hg [34°C], 55 ± 9 vs.59 ± 11 mm Hg [aortic clamp removal], P < 0.0001) at all time points. Venous oxygen saturation remained on comparable levels of >70% during both conventional and minimized cardiopulmonary bypass support. The increase in serum lactate was more pronounced after CCPB (8.98 ± 1.28 vs. 3.66 ± 1.25 mg/dL, P = 0.0079), corresponding to a decrease in serum pH to acidotic levels (7.33 ± 0.06 vs. 7.35 ± 0.06, P < 0.0001). These effects were evident in all BMI ranges. Minimized cardiopulmonary bypass support provides efficient perfusion in all BMI ranges and is thus equivalent to conventional circuits.

D-dimers as an early marker for oxygenator exchange in extracorporeal membrane oxygenation.

PURPOSE: Early markers of oxygenator dysfunction during prolonged use of extracorporeal membrane oxygenation (ECMO) are important for timely exchange to avoid sudden loss of function due to clot formation within the system. The measurement of D-dimers (DDs) in plasma might be a marker for early diagnosis of thrombus formation and dysfunction of heparin-coated membrane oxygenators (MOs). METHODS: This is a retrospective study on prospectively collected data of 24 adult acute respiratory distress syndrome patients requiring long-term veno-venous ECMO with at least 1 MO exchange. Kinetics of coagulation, inflammation, and oxygenator function were analyzed before and after MO exchange. RESULTS: Median (interquartile range) support duration is 20 (15-29) days. Thirty-four MOs had to be replaced. Exchange occurred due to visible thrombus formation in the MO (n=16), worsening gas exchange (n=11), increased blood flow resistance (n=1), and activation of coagulation with diffuse bleeding (n=6). In 15 cases, DDs were continuously elevated and, therefore, not suitable as marker for MO exchange. In the remaining 19 cases, DDs increased significantly within 3 days before exchange from 15 (9-20) to 30 (21-35) mg/dL (P=.002) and declined significantly within 1 day thereafter to 13 (7-17) mg/dL (P=.003). CONCLUSIONS: An increase in plasma DD concentration in absence of other explaining pathology can be helpful in predicting an MO exchange in miniaturized heparin-coated ECMO systems.

The effects of the semirecumbent position on hemodynamic status in patients on invasive mechanical ventilation: prospective randomized multivariable analysis.

INTRODUCTION: Adopting the 45° semirecumbent position in mechanically ventilated critically ill patients is recommended, as it has been shown to reduce the incidence of ventilator-associated pneumonia. Although the benefits to the respiratory system are clear, it is not known whether elevating the head of the bed results in hemodynamic instability. We examined the effect of head of bed elevation (HBE) on hemodynamic status and investigated the factors that influence mean arterial pressure (MAP) and central venous oxygen saturation (ScvO2) when patients were positioned at 0°, 30°, and 45°. METHODS: Two hundred hemodynamically stable adults on invasive mechanical ventilation admitted to a multidisciplinary surgical intensive care unit were recruited. Patients' characteristics included catecholamine and sedative doses, the original angle of head of bed elevation (HBE), the level of positive end expiratory pressure (PEEP), duration and mode of mechanical ventilation. A sequence of HBE positions (0°, 30°, and 45°) was adopted in random order, and MAP and ScvO2 were measured at each position. Patients acted as their own controls. The influence of degree of HBE and of the covariables on MAP and ScvO2 was analyzed by using liner mixed models. Additionally, uni- and multivariable logistic regression models were used to indentify risk factors for hypotension during HBE, defined as MAP <65 mmHg. RESULTS: Changing HBE from supine to 45° caused significant reductions in MAP (from 83.8 mmHg to 71.1 mmHg, P < 0.001) and ScvO2 (76.1% to 74.3%, P < 0.001). Multivariable modeling revealed that mode and duration of mechanical ventilation, the norepinephrine dose, and HBE had statistically significant influences. Pressure-controlled ventilation was the most influential risk factor for hypotension when HBE was 45° (odds ratio (OR) 2.33, 95% confidence interval (CI), 1.23 to 4.76, P = 0.017). CONCLUSIONS: HBE to the 45° position is associated with significant decreases in MAP and ScvO2 in mechanically ventilated patients. Pressure-controlled ventilation, higher simplified acute physiology (SAPS II) score, sedation, high catecholamine, and PEEP requirements were identified as independent risk factors for hypotension after backrest elevation. Patients at risk may need positioning at 20° to 30° to overcome the negative effects of HBE, especially in the early phase of intensive care unit admission.

The effect of perchlorate medication on point-of-care testing.

BACKGROUND: To create awareness for mismeasurements of ion-selective electrodes caused by patients' medications and to prevent severe consequences in an intensive care therapy. CASE PRESENTATION: A 73-year-old woman presented with severe carbimazol-induced toxic epidermal necrolysis. After replacement of carbimazol by sodiumperchlorate, we detected a huge discrepancy in the measurement of ionised calcium by two different Point-of-Care (POCT) systems. While Siemens Rapidlab 865 showed a severe hypocalcemia at all times, the Radiometer 600 system first presented a severe hypercalcemia and, in the course of the following days, also a hypocalcemia but with significantly (p < 10 to the -45) higher values than the Rapidlab system. Furthermore, the POCT systems detected a pseudohypocalcemia at times where we think there was a normo- or even hypercalcemia which led to incorrect therapy with excessive substitution of ionised calcium. CONCLUSIONS: The substance sodiumperchlorate, which is well established in Europe for hyperthyreosis therapy, caused malfunctions of analyses of ionised calcium by POCT systems.

Perchlorate (Irenat®) may falsely lower measured ionised calcium.

BACKGROUND: Discrepancies in ionised calcium concentrations between results from several point-of-care devices derived from intensive care unit (ICU) patients were postulated to be caused by perchlorate, a thyroid blocking agent. The deviations were serious concerning the diagnosis of hyper- or hypocalcaemia and administration of calcium infusions. METHODS: The problem was studied from three perspectives. First: quantification of ionised calcium in heparinised blood samples spiked with sodium perchlorate from healthy volunteers measured using five blood gas analysers (BGAs from IL, Radiometer, Roche and Siemens). Second: verification of clinical concentrations of perchlorate in blood samples after routine use for blood gas analysis from ICU patients. Third: retrospective analysis of data stored from patients during their stay in general ICU of the Departments of Anesthesiology and General Surgery by a patient data management system. RESULTS: Category 1: three of the point-of-care testing devices measure clinically relevant falsely low ionised calcium concentrations when exposed to concentrations perchlorate >0.1 mmol/L. Two were not able to identify hypercalcaemia of up to 4 mmol/L ionised calcium when specific perchlorate concentrations are exceeded. Category 2: measured clinical concentrations of perchlorate ranged between the lower limit of quantification [LOQ=0.03 mmol/L and 2.75 mmol/L (median=0.29 mmol/L; mean=0.585 mmol/L)]. A concentration above 0.1 mmol/L perchlorate was found in 74.3% of all samples that tested positive. Category 3: between February 2006 and July 2009, 42 patients per year (2.2%) received sodium perchlorate with a median length of treatment of 25 days. CONCLUSIONS: Perchlorate causes clinically relevant lowering of measured ionised calcium in BGAs from two providers at concentrations obtained in samples from ICU patients (affecting about 1.1% of all ICU patients).