Refining the hospitalization rate: A mixed methods approach to differentiate primary COVID-19 from incidental cases.

Purpose: Until now, the Hospitalization Rate (HR) served as an indicator (among others) for the COVID-19 associated healthcare burden. To ensure that the HR accomplishes its full potential, hospitalizations caused by COVID-19 (primary cases) and hospitalizations of patients with incidental positive SARS-CoV-2 test results (incidental cases) must be differentiated. The aim of this study was to synthesize the existing evidence on differentiation criteria between hospitalizations of primary cases and incidental cases. Methods: An online survey of the members of the German Network University Medicine (NUM) was conducted. Additionally, senior clinicians with expertise in COVID-19 care were invited for qualitative, semi-structured interviews. Furthermore, a rapid literature review was undertaken on publications between 03/2020 and 12/2022. Results: In the online survey (n=30, response rate 56%), pneumonia and acute upper respiratory tract infections were the most indicative diagnoses for a primary case. In contrast, malignant neoplasms and acute myocardial infarctions were most likely to be associated with incidental cases. According to the experts (n=6), the diagnosis, ward, and type of admission (emergency or elective), low oxygen saturation, need for supplemental oxygen, and initiation of COVID-19 therapy point to a primary case. The literature review found that respiratory syndromes and symptoms, oxygen support, and elevated levels of inflammatory markers were associated with primary cases. Conclusion: There are parameters for the differentiation of primary from incidental cases to improve the objective of the HR. Ultimately, an updated HR has the potential to serve as a more accurate indicator of the COVID-19 associated healthcare burden.

Mechanical power of ventilation and driving pressure: two undervalued parameters for pre extracorporeal membrane oxygenation ventilation and during daily management?

The current ARDS guidelines highly recommend lung protective ventilation which include plateau pressure (Pplat < 30 cm H2O), positive end expiratory pressure (PEEP > 5 cm H2O) and tidal volume (Vt of 6 ml/kg) of predicted body weight. In contrast, the ELSO guidelines suggest the evaluation of an indication of veno-venous extracorporeal membrane oxygenation (ECMO) due to hypoxemic or hypercapnic respiratory failure or as bridge to lung transplantation. Finally, these recommendations remain a wide range of scope of interpretation. However, particularly patients with moderate-severe to severe ARDS might benefit from strict adherence to lung protective ventilation strategies. Subsequently, we discuss whether extended physiological ventilation parameter analysis might be relevant for indication of ECMO support and can be implemented during the daily routine evaluation of ARDS patients. Particularly, this viewpoint focus on driving pressure and mechanical power.

Prevalence of pre-operative anaemia in surgical patients: a retrospective, observational, multicentre study in Germany.

Anaemia is a risk factor for several adverse postoperative outcomes. Detailed data about the prevalence of anaemia are not available over a long time-period in Germany. In this retrospective, observational, multicentre study, patients undergoing surgery in March in 2007, 2012, 2015, 2017 and 2019 were studied. The primary objective was the prevalence of anaemia at hospital admission. The secondary objectives were the association between anaemia and the number of units of red blood cells transfused, length of hospital stay and in-hospital mortality. A total of 23,836 patients were included from eight centres. The prevalence of pre-operative anaemia in patients aged ≥ 18 years decreased slightly from 37% in 2007 to 32.5% in 2019 (p = 0.01) and increased in patients aged ≤ 18 years from 18.8% in 2007 to 26.4% in 2019 (p > 0.001). The total amount of blood administered per 1000 patients decreased from 671.2 units in 2007 to 289.0 units in 2019. Transfusion rates in anaemic patients declined from 33.8% in 2007 to 19.1% in 2019 (p < 0.001) and in non-anaemic patients from 8.4% in 2007 to 3.4% in 2019 (p < 0.001). Overall, the mortality rate remained constant over the years: 2.9% in 2007, 2.1% in 2012, 2.5% in 2015, 1.9% in 2017 and 2.5% in 2019. In the presence of anaemia, mortality was significantly increased compared with patients without anaemia (OR 5.27 (95%CI 4.13-6.77); p < 0.001). Red blood cell transfusion was associated with an increased risk of mortality (OR 14.98 (95%CI 11.83-19.03); p < 0.001). Using multivariable linear regression analysis with fixed effects, we found that pre-operative anaemia (OR 2.08 (95%CI 1.42-3.05); p < 0.001) and red blood cell transfusion (OR 4.29 (95%CI 3.09-5.94); p < 0.001) were predictors of mortality but not length of stay (0.99 (95%CI 0.98-1.00) days; p = 0.12) and analysed years (2007 vs. 2019: OR 1.49 (95%CI 0.86-2.69); p = 0.07). Pre-operative anaemia affects more than 30% of surgical patients in Germany and multidisciplinary action is urgently required to reduce adverse outcomes.

[Reticulocyte hemoglobin equivalent as a diagnostic marker for the current iron deficiency : Old wine in new bottles]. / Retikulozyten-Hämoglobin-Äquivalent als diagnostischer Marker der aktuellen Eisendefizienz : Alter Wein in neuen Schläuchen.

The reticulocyte hemoglobin equivalent (RET-He) is presented as a biomarker for the diagnostics and monitoring of iron deficiency. The marker is independent of the acute phase and can be determined within a few minutes by a blood count. Due to the approximately 120-day lifetime of erythrocytes, iron deficiency and changes in the iron status of erythropoiesis can first be recognized at a relatively late stage using classical hematological parameters, such as hemoglobin, mean corpuscular volume, mean cellular hemoglobin content and also with determination of hypochromic erythrocytes (% hypo). The RET-He is a cost-effective parameter for the diagnosis and monitoring of the iron supply for erythropoiesis. Reticulocytes, the precursors of mature erythrocytes, are washed out of the bone marrow into the peripheral blood and normally mature within 2 days to mature erythrocytes. The determination of the reticulocyte number therefore enables a timely statement about erythropoiesis. A measurement of the hemoglobin content of reticulocytes therefore reflects the actual iron metabolism of erythropoiesis and enables assessment of the quality of the cells. Changes in the iron status of erythropoiesis can thus be detected much earlier than by determining only the hemoglobin content of mature erythrocytes, i.e. the mean cellular hemoglobin content. It is recommended that the evaluation of RET-He should be carried out as an inexpensive routine preoperative marker of latent anemia in order to identify patients at risk. In the sense of a perioperative prehabilitation and the enhanced recovery after surgery (ERAS) concept, patients with iron deficiency can be treated proactively at an early stage in order to prevent complications and extended hospital stays.

Surgery in times of COVID-19-recommendations for hospital and patient management.

BACKGROUND: The novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has escalated rapidly to a global pandemic stretching healthcare systems worldwide to their limits. Surgeons have had to immediately react to this unprecedented clinical challenge by systematically repurposing surgical wards. PURPOSE: To provide a detailed set of guidelines developed in a surgical ward at University Hospital Wuerzburg to safely accommodate the exponentially rising cases of SARS-CoV-2 infected patients without compromising the care of emergency surgery and oncological patients or jeopardizing the well-being of hospital staff. CONCLUSIONS: The dynamic prioritization of SARS-CoV-2 infected and surgical patient groups is key to preserving life while maintaining high surgical standards. Strictly segregating patient groups in emergency rooms, non-intensive care wards and operating areas prevents viral spread while adequately training and carefully selecting hospital staff allow them to confidently and successfully undertake their respective clinical duties.

Patient blood management during the COVID-19 pandemic: a narrative review.

As COVID-19 disease escalates globally, optimising patient outcome during this catastrophic healthcare crisis is the number one priority. The principles of patient blood management are fundamental strategies to improve patient outcomes and should be given high priority in this crisis situation. The aim of this expert review is to provide clinicians and healthcare authorities with information regarding how to apply established principles of patient blood management during the COVID-19 pandemic. In particular, this review considers the impact of the COVID-19 pandemic on blood supply and specifies important aspects of donor management. We discuss how preventative and control measures implemented during the COVID-19 crisis could affect the prevalence of anaemia, and highlight issues regarding the diagnosis and treatment of anaemia in patients requiring elective or emergency surgery. In addition, we review aspects related to patient blood management of critically ill patients with known or suspected COVID-19, and discuss important alterations of the coagulation system in patients hospitalised due to COVID-19. Finally, we address special considerations pertaining to supply-demand and cost-benefit issues of patient blood management during the COVID-19 pandemic.

[Preoperative iron deficiency with/without anemia-an underestimated risk factor?] / Präoperativer Eisenmangel mit/ohne Anämie ­ ein unterschätzter Risikofaktor?

BACKGROUND: Every third surgical patient already suffers from anemia before surgery. The main cause is iron deficiency. OBJECTIVE: This article describes the perioperative risk of iron deficiency with/without anemia and summarizes potential preventive measures. MATERIAL AND METHODS: Presentation of various current original papers, guidelines and own experiences from the German patient blood management network. RESULTS AND CONCLUSION: Preoperative iron deficiency with/without anemia is an underestimated risk factor for perioperative complications. The implementation of preoperative diagnostics and treatment as part of a comprehensive patient blood management reduces complications and increases patient safety.

[Various scenarios for billing and remuneration of preoperative management of iron deficiency anemia in the German healthcare system]. / Verschiedene Szenarien zu Abrechnung und Kostenerstattung eines präoperativen Managements der Eisenmangelanämie im deutschen Gesundheitssystem.

More than 30% of all patients undergoing surgery suffer from preoperative anemia. Iron deficiency anemia is the most common type of anemia. The diagnostics and treatment of iron deficiency anemia can be carried out before patients undergo surgery as an alternative to blood transfusion and is an interdisciplinary task. This article gives an overview of various billing modalities and payment arrangements for management of preoperative anemia in the German healthcare system.

An international consensus statement on the management of postoperative anaemia after major surgical procedures.

Despite numerous guidelines on the management of anaemia in surgical patients, there is no pragmatic guidance for the diagnosis and management of anaemia and iron deficiency in the postoperative period. A number of experienced researchers and clinicians took part in a two-day expert workshop and developed the following consensus statement. After presentation of our own research data and local policies and procedures, appropriate relevant literature was reviewed and discussed. We developed a series of best-practice and evidence-based statements to advise on patient care with respect to anaemia and iron deficiency in the postoperative period. These statements include: a diagnostic approach to iron deficiency and anaemia in surgical patients; identification of patients appropriate for treatment; and advice on practical management and follow-up that is easy to implement. Available data allow the fulfilment of the requirements of Pillar 1 of Patient Blood Management. We urge national and international research funding bodies to take note of these recommendations, particularly in terms of funding large-scale prospective, randomised clinical trials that can most effectively address the important clinical questions and this clearly unmet medical need.

[The patient blood management concept : Joint recommendation of the German Society of Anaesthesiology and Intensive Care Medicine and the German Society of Surgery]. / Das Patient-Blood-Management-Konzept : Gemeinsame Empfehlung der Deutschen Gesellschaft für Anästhesiologie und Intensivmedizin und der Deutschen Gesellschaft für Chirurgie.

Patient blood management is a multimodal concept that aims to detect, prevent and treat anemia, optimize hemostasis, minimize iatrogenic blood loss, and support a patient-centered decision to provide optimal use of allogeneic blood products. Although the World Health Organization (WHO) has already recommended patient blood management as a new standard in 2010, many hospitals have not implemented it at all or only in part in clinical practice. The German Society of Anaesthesiology and Intensive Care Medicine and the German Society of Surgery therefore demand that i) all professionals involved in the treatment should implement important aspects of patient blood management considering local conditions, and ii) the structural, administrative and budgetary conditions should be created in the health care system to implement more intensively many of the measures in Germany.

International consensus statement on the peri-operative management of anaemia and iron deficiency.

Despite current recommendations on the management of pre-operative anaemia, there is no pragmatic guidance for the diagnosis and management of anaemia and iron deficiency in surgical patients. A number of experienced researchers and clinicians took part in an expert workshop and developed the following consensus statement. After presentation of our own research data and local policies and procedures, appropriate relevant literature was reviewed and discussed. We developed a series of best-practice and evidence-based statements to advise on patient care with respect to anaemia and iron deficiency in the peri-operative period. These statements include: a diagnostic approach for anaemia and iron deficiency in surgical patients; identification of patients appropriate for treatment; and advice on practical management and follow-up. We urge anaesthetists and peri-operative physicians to embrace these recommendations, and hospital administrators to enable implementation of these concepts by allocating adequate resources.

[Cardioprotection in cardiac surgical patients : Everything good comes from the heart]. / Kardioprotektion beim herzchirurgischen Patienten : Alles Gute kommt von Herzen.

BACKGROUND: Despite substantial success in the anesthetic and surgical management of cardiac surgery, patients frequently show postoperative complications and organ dysfunctions. This is highly relevant for mid- to long-term outcomes. OBJECTIVES: To evaluate cardioprotective strategies that may offer effective protection in vulnerable cardiac surgery patients. METHODS: To demonstrate recent cardioprotective approaches for cardiac surgery patients, aiming to modulate the body's own protective mechanisms in cardiac surgery patients. RESULTS: Both cardioplegia and hypothermia belong to the well-established protective strategies during myocardial ischemia. Volatile anesthetics have been repeatedly shown to improve the left ventricular function and reduce the extent of myocardial injury compared to a control group with intravenous anesthesia. Furthermore, patients receiving volatile anesthetics showed a significantly shortened stay in the ICU and in hospital after cardiac surgery. In contrast, numerous other protective strategies failed translation into the clinical practice. Despite the published reduction of troponin release after remote ischemic preconditioning, two recent large-scale randomized multicenter trials were unable to demonstrate a clinical benefit. CONCLUSIONS: Beside the use of cardioplegia and hypothermia, the use of volatile anesthetics is well-established during cardiac surgery because of its conditioning and protective properties. Regardless of the promising results derived from experimental studies and small clinical trials, the majority of other approaches failed to translate their findings into the clinic. Therefore, systematic experimental studies are needed to identify potential confounding factors that may affect the protective effects.

Risk factors associated with adverse outcome following extracorporeal life support: analysis from 360 consecutive patients.

OBJECTIVE: Risk factors for adverse outcome after extracorporeal life support (ECLS) are yet to be defined. For this purpose, we reviewed our institutional data from more than a decade, focusing on patients with ECLS. METHODS: Between December 2001 and June 2013, 360 consecutive cardiac surgical patients received ECLS for post-cardiotomy cardiogenic shock, with high mortality risk despite optimal conventional therapy. Patient demographics, clinical characteristics, ECLS-related morbidity, as well as in-hospital and long-term mortality were analysed. Multivariate logistic regression analysis was performed to identify independent predictors of adverse outcome (failed ECLS weaning, in-hospital mortality). RESULTS: The mean age was 62±17 years, 76% were male and the mean preoperative ejection fraction was 35±16%. ECLS was established through peripheral (90%) or central thoracic cannulation. The mean duration of ECLS was 7±1 days. Intra-aortic balloon pumps were implanted in 22% of the patients. ECLS weaning was successful in 58% and 30% could be discharged from hospital. The main cause of death was sepsis (69%). Overall, major cerebrovascular events occurred in 12% (bleeding 3%, embolic 9%), limb ischaemia in 13%, gastrointestinal complications in 16% and renal replacement therapy in 61%. Independent risk factors for adverse outcome were prior cardiorespiratory resuscitation (OR: 4.1, 95%CI: 0.34-4.21, p=0.04), pH <7.1 (OR: 2.8, 95%CI: 0.45-3.28, p=0.01), serum lactate >120 mg/dL (OR: 2.6, 95%CI: 0.75-2.96, p< 0.01), norepinephrine dosage >0.5 µg/kg/min (OR: 2.4, 95%CI: 0.35-2.92, p=0.02) and age >75 years (OR: 2.0, 95%CI: 0.41-2.88, p=0.02). Kaplan Meier estimates for long-term survival were 26±3% at one year and 22±2% at five years. CONCLUSION: ECLS therapy offers one-year survival to one quarter of patients with an otherwise fatal prognosis. Procedural mortality is low and morbidity at the implantation site typically moderate. Thus, prolonged metabolic deterioration in combination with high-dose vasopressor support prior to ECLS therapy should be avoided, particularly in younger patients.

Remote preconditioning and major clinical complications following adult cardiovascular surgery: systematic review and meta-analysis.

BACKGROUND: A number of 'proof-of-concept' trials suggest that remote ischaemic preconditioning (RIPC) reduces surrogate markers of end-organ injury in patients undergoing major cardiovascular surgery. To date, few studies have involved hard clinical outcomes as primary end-points. METHODS: Randomised clinical trials of RIPC in major adult cardiovascular surgery were identified by a systematic review of electronic abstract databases, conference proceedings and article reference lists. Clinical end-points were extracted from trial reports. In addition, trial principal investigators provided unpublished clinical outcome data. RESULTS: In total, 23 trials of RIPC in 2200 patients undergoing major adult cardiovascular surgery were identified. RIPC did not have a significant effect on clinical end-points (death, peri-operative myocardial infarction (MI), renal failure, stroke, mesenteric ischaemia, hospital or critical care length of stay). CONCLUSION: Pooled data from pilot trials cannot confirm that RIPC has any significant effect on clinically relevant end-points. Heterogeneity in study inclusion and exclusion criteria and in the type of preconditioning stimulus limits the potential for extrapolation at present. An effort must be made to clarify the optimal preconditioning stimulus. Following this, large-scale trials in a range of patient populations are required to ascertain the role of this simple, cost-effective intervention in routine practice.

A comparison of the Nexfin® and transcardiopulmonary thermodilution to estimate cardiac output during coronary artery surgery.

The newly introduced Nexfin(®) device allows analysis of the blood pressure trace produced by a non-invasive finger cuff. We compared the cardiac output derived from the Nexfin and PiCCO, using transcardiopulmonary thermodilution, during cardiac surgery. Forty patients with preserved left ventricular function undergoing elective coronary artery bypass graft surgery were studied after induction of general anaesthesia and until discharge to the intensive care unit. There was a significant correlation between Nexfin and PiCCO before (r(2) = 0.81, p < 0.001) and after (r(2) = 0.56, p < 0.001) cardiopulmonary bypass. Bland-Altman analysis demonstrated the mean bias of Nexfin to be -0.1 (95% limits of agreement -0.6 to +0.5, percentage error 23%) and -0.1 (-0.8 to +0.6, 26%) l.min(-1).m(-2), before and after cardiopulmonary bypass, respectively. After a passive leg-raise was performed, there was also good correlation between the two methods, both before (r(2) = 0.72, p < 0.001) and after (r(2) = 0.76, p < 0.001) cardiopulmonary bypass. We conclude that the Nexfin is a reliable method of measuring cardiac output during and after cardiac surgery.

Electrophysiologic neuromonitoring during repair of the thoracoabdominal aorta by anesthesiologists.

BACKGROUND: Surgical repair of the thoracoabdominal aorta is associated with risk of spinal ischemia. Electrophysiologic neuromonitoring reduces this risk, but is usually performed by neurophysiologists not always available. In this study repair of the thoracoabdominal aorta monitored by anesthesiologists has been investigated. METHODS: Somatosensory and transcranial electrical motor evoked potentials were monitored in 20 patients. A lumbar intraspinal fluid drainage was inserted. Dacron graft replacement of the aorta was performed by sequentially clamping during partial cardiopulmonary bypass. Loss or decrease of amplitudes of evoked potentials of more than 50% prompted reinsertion of spinal arteries in the graft. RESULTS: One patient not monitored with motor evoked potentials due to indwelling cardiac pacemaker had postoperative paraplegia. Somatosensory and motor evoked potentials were recordable in all other patients. Two patients died during surgery, one patient died postoperatively. No surviving patient monitored with somatosensory and motor evoked potentials had neurologic deficits. CONCLUSION: Electrophysiologic neuromonitoring during surgical repair of the descending aorta can be successfully provided by anesthesiologists and should be predominately encouraged where neurophysiologists are not available due to organizational or financial shortcomings.

Accuracy of the pleth variability index to predict fluid responsiveness depends on the perfusion index.

BACKGROUND: Respiratory variations in plethysmographic waveform amplitudes derived from pulse oximetry are believed to predict fluid responsiveness. The non-invasive pleth variability index (PVI) is a variable based on the calculation of changes in the perfusion index (PI). The aim of the following study was to examine whether the predictive power of PVI depends on different values of PI. METHODS: Eighty-one patients undergoing elective coronary artery surgery were studied before operation: at baseline after induction of anaesthesia and during passive leg raising (PLR). Each patient was monitored with central venous pressure (CVP), the PiCCO monitor and the non-invasive Masimo monitoring system. Stroke volume index by transpulmonary thermodilution (SVI(TPTD)), pulse pressure variation (PPV), stroke volume variation (SVV) and systemic vascular resistance index (SVRI) were measured using the PiCCO monitoring system. PI and PVI were obtained by pulse oximetry. RESULTS: Responders were defined to increase their SVI(TPTD) >15% after PLR. The highest area under the curve (AUC) was found for PPV (AUC: 0.83, P<0.0001) and SVV (AUC: 0.72, P=0.002), in contrast to PVI (AUC: 0.60, P=0.11) and CVP (AUC: 0.60, P=0.13). The accuracy of PVI to predict fluid responsiveness was improved on analysing patients with higher PI values. PI of about 4% (n=45) achieved statistical significance (AUC: 0.72, P=0.01). CONCLUSION: The PVI was not able to predict fluid responsiveness with sufficient accuracy. In patients with higher perfusion states, the PVI improved its ability to predict haemodynamic changes, strongly suggesting a relevant influence of the PI on the PVI.

Differences between bispectral index and spectral entropy during xenon anaesthesia: a comparison with propofol anaesthesia.

We enrolled 114 patients, aged 65-83 years, undergoing elective surgery (duration > 2h) into a randomised, controlled study to evaluate the performance of bispectral index and spectral entropy for monitoring depth of xenon versus propofol anaesthesia. In the propofol group, bispectral index and state entropy values were comparable. In the xenon group, bispectral index values resembled those in the propofol group, but spectral entropy levels were significantly lower. Mean arterial blood pressure was higher and heart rate was lower in the xenon group than in the propofol group. Bispectral index and spectral entropy considerably diverged during xenon but not during propofol anaesthesia. We therefore conclude that these measures are not interchangeable for the assessment of depth of hypnosis and that bispectral index is likely to reflect actual depth of anaesthesia more precisely compared with spectral entropy.