Purpose of the reviewThe mediastinal mass syndrome (MMS) can occur after induction of anesthesia, intraoperatively or even days after the surgical procedure. The focus of this review is on the management of pediatric and adult patients with a significant mediastinal mass.Recent findingsThe age distribution of patients with mediastinal lesions suggests a bimodal shape, with an increased incidence among children under 10 years old and adults aged 60-70 years old. The traditional approach to avoid general anesthesia and mechanical ventilation has been challenged recently. Induction of general anesthesia may be achieved by a titrated intravenous infusion of propofol, with the patient positioned in a semi-sitting position. Mechanical ventilation with a prolonged I:E ratio, low respiratory rate and rigid or flexible bronchoscopy to stent the obstructed airway can facilitate expiration of tidal volume. Continuous video bronchoscopy recordings of the compromised portion of the airway have shown that positive pressure ventilation and neuromuscular blockade can induce an increase in the mean airway patency score.SummaryMeticulous planning, implementation of anesthetic management protocols and protocols for emergency situations are essential to guarantee patient safety with a mediastinal mass.

Zusammenfassung Hintergrund Die Hochfrequenz-Jetventilation (HFJV) wird in der pneumologischen Endoskopie für starre, diagnostische und therapeutische Bronchoskopien genutzt. Unklar ist hierbei, inwieweit durch den ungehinderten Atemgasstrom aus der Lunge des Patienten eine mikrobielle Belastung der Umgebungsluft entsteht. Material und Methoden Nach Beginn der HFJV (15 min) bei 16 starren Bronchoskopien wurden direkt am distalen Endoskopausgang, auf Untersucherhöhe (40 cm über dem Endoskopausgang), in 2 m Abstand vom Endoskop im Raum sowie am Zuluftauslass des Untersuchungsraums Luftkeimmessungen mit einem RCS-Luftkeimsammler vorgenommen. Anschließend erfolgten die Bestimmung der Anzahl und Art der isolierten Erreger in den Luftproben sowie eine Keimbestimmung in der bronchoalveolären Lavageflüssigkeit (BALF) aus der Patientenlunge. Ergebnisse Direkt am distalen Ende des Endoskops und auf Untersucherhöhe in 40 cm Entfernung wurde eine erhöhte Keimdichte (136 und 114 KBE/m3) nachgewiesen, die mit zunehmendem Abstand vom Bronchoskop deutlich abnahm (in 2 m Entfernung 98 KBE/m3 und am Zuluftauslass 82 KBE/m3). Die am häufigsten nachgewiesenen Bakterien waren Staphylococcus spp., Micrococcus spp. und Bacillus spp. In der BALF konnten nur in 4 von 16 Proben Erreger kultiviert werden, jedoch wurden dieselben Erreger in der BALF und der Umgebungsluft nachgewiesen. Schlussfolgerungen Bei der Durchführung einer starren Bronchoskopie, bei der die Patienten mit einem offenen HFJV-System kontrolliert mechanisch ventiliert werden, entsteht eine erhöhte Erregerbelastung der Umgebungsluft und damit eine potenzielle Gefahr für den Untersucher.

Background High-frequency jet ventilation (HFJV) is used in pneumological endoscopy for rigid, diagnostic, and therapeutic bronchoscopies. It is unclear to what extent the unobstructed flow of respiratory gas from the patient's lungs causes microbial contamination of the surrounding air. Material and methods After the start of the HFJV (15 min) in 16 rigid bronchoscopies, airborne pathogen measurements were taken directly at the distal endoscope outlet, at examiner height (40 cm above the endoscope outlet), at a 2 m distance from the endoscope in the room and at the supply air outlet of the examination room using an RCS air sampler. The number and type of pathogens isolated in the air samples were then determined, as well as germs in the bronchoalveolar lavage fluid (BALF) from the patient's lungs. Results An increased bacterial density (136 and 114 CFU/m (3) ) was detected directly at the distal end of the endoscope and at examiner height at a distance of 40 cm, which decreased significantly with increasing distance from the bronchoscope (98 CFU/m (3 )at a distance of 2 m and 82 CFU/m (3) at the supply air outlet). The most frequently detected bacteria were Staphylococcus spp., Micrococcus spp. and Bacillus spp. In the BALF, pathogens could only be cultivated in four of 16 samples, but the same pathogens were detected in the BALF and the ambient air. Conclusion When performing a rigid bronchoscopy, in which patients are mechanically ventilated in a controlled manner using an open HFJV system, there is an increased pathogen load in the ambient air and therefore a potential risk for the examiner.

Hintergrund Rupturen der zentralen Atemwege sind äußerst seltene, aber akut lebensbedrohliche Verletzungen, die bei Hochgeschwindigkeits-Dezelerationstraumen auftreten. Die Verletzungen treten typischerweise zusammen mit Verletzungen der Halswirbelsäule auf. Die Diagnose erfordert deshalb ein hohes Maß an klinischer Vigilanz und die Versorgung ein abgestimmtes Vorgehen zwischen verschiedenen chirurgischen Fachdisziplinen.

Das Mediastinal-mass-Syndrom (MMS) ist eine lebensbedrohliche Anästhesiekomplikation, deren Vermeidung und Behandlung eine komplikationsträchtige, interdisziplinäre Aufgabe darstellt. Die Symptomatik variiert je nach Ausdehnung und Größe eines Mediastinaltumors sowie der Beteiligung entsprechender anatomischer Strukturen von asymptomatischen Patienten bis hin zu lebensbedrohlichen, kardiorespiratorischen Einschränkungen. Insbesondere im Rahmen einer Sedierung oder Allgemeinanästhesie besteht das Risiko der akuten kardiopulmonalen oder respiratorischen Dekompensation infolge einer tumorbedingten Kompression zentraler Blutgefäße oder der Atemwege, die nicht selten schwerwiegende Komplikationen bis hin zum Tode nach sich ziehen. In dieser Fallserie werden drei Patientinnen vorgestellt, die uns jeweils mit einem mediastinalen Tumor zur interventionellen bzw. operativen Diagnosesicherung zugewiesen wurden. Anhand der Kasuistiken werden typische Komplikationen demonstriert sowie Strategien zur Vermeidung möglicher Zwischenfälle eines MMS diskutiert. Die spezifischen anästhesiologischen Anforderungen durch das MMS, die Sicherheitsaspekte der Wahl der Operations- und Anästhesieverfahren, das Kreislauf- und Atemwegsmanagement für die erforderliche Einlungenventilation sowie verschiedene Aspekte zur Auswahl der Anästhetika werden in dieser Fallserie erörtert.

Hintergrund Das Mediastinal Mass Syndrom (MMS) kann durch die Kompression der großen Blutgefäße oder Atemwege, hervorgerufen durch einen großen mediastinalen Tumor, zu einer akuten fatalen kardiopulmonalen Dekompensation führen. Diese tritt insbesondere im Rahmen einer Sedierung oder Narkose auf, so dass das Behandlungsteam aus Onkologen, Anästhesisten und Chirurgen vor eine komplexe Herausforderung gestellt wird.

Background: Patients with Coronavirus Disease (COVID-19) often develop severe acute respiratory distress syndrome (ARDS) requiring prolonged mechanical ventilation (MV), and venovenous extracorporeal membrane oxygenation (V-V ECMO). Mortality in COVID-19 patients on V-V ECMO was exceptionally high; therefore, whether sur-vival can be ameliorated should be investigated. Methods: We collected data from 85 patients with severe ARDS who required ECMO support at the University Hospital Magdeburg from 2014 to 2021. The patients were divided into the COVID-19 group (52 patients) and the non-COVID-19 group (33 patients). Demographic and pre-, intra-, and post-ECMO data were retrospectively recorded. The parameters of mechanical ventilation, lab-oratory data before using ECMO, and during ECMO were compared.Results: There was a significant difference between the two groups regarding survival: 38.5% of COVID-19 patients and 63.6% of non-COVID-19 patients survived 60 days (p = 0.024). COVID-19 patients required V-V ECMO after 6.5 days of MV, while non-COVID-19 patients required V-V ECMO after 2.0 days of MV (p = 0.048). The COVID-19 group had a greater proportion of patients with ischemic heart disease (21.2% vs 3%, p = 0.019). The rates of most complications were comparable in both groups, whereas the COVID-19 group showed a significantly higher rate of cerebral bleeding (23.1 vs 6.1%, p = 0.039) and lung bacterial superinfection (53.8% vs 9.1%, p = <0.001).Conclusion: The higher 60-days mortality among patients with COVID-19 with severe ARDS was attributable to superinfection, a higher risk of intracerebral bleeding, and the pre-existing ischemic heart disease.

ZusammenfassungDie kongenitale Muskeldystrophie Typ Ullrich (UCMD) ist eine seltene Erkrankung. Weltweit wurden bislang 50 Fälle genetisch gesichert. Autosomal-dominante und rezessive Mutationen des COL6A1/COL6A2 im Chromosom 21q22.3 oder des COL6A3 im Chromosom 2q37.3 führen zu einem Mangel an Kollagen VI. Typische Merkmale der UCMD sind Muskelschwäche von Körperstamm und Extremitäten, Hyperflexibilität der distalen und Kontrakturen der proximalen Gelenke, Rollstuhlpflichtigkeit im Alter von 9 bis 11 Jahren, Versteifung und Skoliose der Wirbelsäule und eine progrediente restriktive Ventilationsstörung. Etwa 50 % der Kinder benötigen im Alter von 11 bis 12 Jahren eine nichtinvasive Ventilation (NIV), wozu auch eine gestörte Funktion des Diaphragmas beiträgt. Es wird über die Narkose bei einer 21-jährigen Patientin mit einer UCMD berichtet, die seit dem 6. Lebensjahr rollstuhlpflichtig war und bei der seit 2018 eine lebenserhaltene NIV erfolgte. Wegen einer subpleuralen Einblutung in den linken Lungenunterlappen nach Entlastung eines Pneumothorax wurde eine videoassistierte thorakoskopische Chirurgie (VATS) vorgenommen. Die spezifischen Anforderungen durch die UCMD, das Atemwegsmanagement für die Einlungenventilation sowie Aspekte zur Auswahl der Anästhetika werden diskutiert. Nach erfolgreicher VATS konnte die Patientin am 7. postoperativen Tag in die Häuslichkeit entlassen werden.

One-lung ventilation is required for thoracic surgery interventions; however, it can impair ventilation/perfusion (VA/Q) matching, thus putting the patient at increased risk for hypoxemia that might compromise the overall outcome. Both anesthetic and surgical management may influence the pulmonary and systemic reaction. Concerning the anesthetic management, plenty of research has been undertaken to highlight the impact of anesthetic drugs and ventilatory settings, especially the use of pressures and volumes. Intraoperative hypoxia and its consequences have been widely elucidated, opening the way for VA/Q matching to reach the focus of interest. Several drugs that affect the vasculature and/or the respiratory system have been analyzed, as they might lead to dilation or constriction within the pulmonary vessels and therefore impact on VA/Q relation. One of the key issues in anesthetic management is to impede a rise in pulmonary vascular resistance and a rise in cardiac oxygen demand. Inhalational agents, such as nitric oxide or prostacyclin analogs, act as potent vasodilators that do not compromise systemic vascular resistance, as they act locally in the ventilated areas. Phosphodiesterase inhibitors have promising effects on VA/Q matching, as well as the chemoreceptor agonist almitrine. Even though calcium channel blockers and endothelin receptor antagonists do not play a role within the intraoperative setting, they will be frequently encountered in patients suffering from pulmonary hypertension. Pulmonary vasculature and perfusion distribution are also affected by several vasoconstricting agents, such as catecholamines or by different vasodilators and inotropes. All of them impact on VA/Q relation depending on their site of action and can thus influence management in thoracic anesthesia.

ZusammenfassungDas Management der Ein-Lungen-Ventilation (ELV) beinhaltet mehrere Herausforderungen. Diese umfassen die adäquate Oxygenierung und Ventilation und den Schutz der Lunge vor pathophysiologischen Noxen zur Vermeidung postoperativer pulmonaler Komplikationen. Während der ELV wird die Belüftung des zu operierenden Lungenflügels durch verschiedene Techniken unterbrochen, während die Perfusion in vermindertem Umfang erhalten bleibt. Das entsprechende Tidalvolumen (VT) wird somit lediglich einer Lunge zugeführt.Die derzeitigen Empfehlungen zur Aufrechterhaltung des Gasaustausches und die lungenprotektiven Maßnahmen können sich diametral widersprechen, wie z. B. die Applikation einer hohen vs. niedrigen inspiratorischen Sauerstofffraktion (FiO2) oder die eines hohen vs. niedrigen Atemzugvolumens. Angesichts der limitierten Evidenz beleuchtet diese Arbeit aktuelle intraoperative Strategien für die ELV, welche die Reduktion der FiO2, ein niedriges VT, die Applikation eines positiven endexspiratorischen Druckes (PEEP) in der ventilierten Lunge und eines kontinuierlichen positiven Atemwegsdruckes (CPAP) in der nicht ventilierten Lunge sowie alveoläre Rekrutierungsmanöver umfassen. Weitere Ansätze, wie die Wahl des Anästhesieverfahrens, die ischämische Präkonditionierung, das hämodynamische Management und die Volumentherapie sowie die postoperative Schmerztherapie können die lungenprotektiven Strategien unterstützen und das klinische Ergebnis verbessern.

Background: Kinetics of the uptake of inhaled anesthetics have been well studied, but the kinetics of elimination might be of more practical importance. The objective of the authors' study was to assess the effect of the overall ventilation/perfusion ratio (V-A/Q), for normal lungs, on elimination kinetics of desflurane and sevoflurane. Methods: The authors developed a mathematical model of inhaled anesthetic elimination that explicitly relates the terminal washout time constant to the global lung V-A/Q ratio. Assumptions and results of the model were tested with experimental data from a recent study, where desflurane and sevoflurane elimination were observed for three different V-A/Q conditions: normal, low, and high. Results: The mathematical model predicts that the global V-A/Q ratio, for normal lungs, modifies the time constant for tissue anesthetic washout throughout the entire elimination. For all three V-A/Q conditions, the ratio of arterial to mixed venous anesthetic partial pressure P-art/P-mv reached a constant value after 5 min of elimination, as predicted by the retention equation. The time constant corrected for incomplete lung clearance was a better predictor of late-stage kinetics than the intrinsic tissue time constant. Conclusions: In addition to the well-known role of the lungs in the early phases of inhaled anesthetic washout, the lungs play a long-overlooked role in modulating the kinetics of tissue washout during the later stages of inhaled anesthetic elimination. The V-A/Q ratio influences the kinetics of desflurane and sevoflurane elimination throughout the entire elimination, with more pronounced slowing of tissue washout at lower V-A/Q ratios.

Background Previous studies have established the role of various tissue compartments in the kinetics of inhaled anesthetic uptake and elimination. The role of normal lungs in inhaled anesthetic kinetics is less understood. In juvenile pigs with normal lungs, the authors measured desflurane and sevoflurane washin and washout kinetics at three different ratios of alveolar minute ventilation to cardiac output value. The main hypothesis was that the ventilation/perfusion ratio (VA/Q) of normal lungs influences the kinetics of inhaled anesthetics. Methods Seven healthy pigs were anesthetized with intravenous anesthetics and mechanically ventilated. Each animal was studied under three different VA/Q conditions: normal, low, and high. For each VA/Q condition, desflurane and sevoflurane were administered at a constant, subanesthetic inspired partial pressure (0.15 volume% for sevoflurane and 0.5 volume% for desflurane) for 45 min. Pulmonary arterial and systemic arterial blood samples were collected at eight time points during uptake, and then at these same times during elimination, for measurement of desflurane and sevoflurane partial pressures. The authors also assessed the effect of VA/Q on paired differences in arterial and mixed venous partial pressures. Results For desflurane washin, the scaled arterial partial pressure differences between 5 and 0 min were 0.70 ± 0.10, 0.93 ± 0.08, and 0.82 ± 0.07 for the low, normal, and high VA/Q conditions (means, 95% CI). Equivalent measurements for sevoflurane were 0.55 ± 0.06, 0.77 ± 0.04, and 0.75 ± 0.08. For desflurane washout, the scaled arterial partial pressure differences between 0 and 5 min were 0.76 ± 0.04, 0.88 ± 0.02, and 0.92 ± 0.01 for the low, normal, and high VA/Q conditions. Equivalent measurements for sevoflurane were 0.79 ± 0.05, 0.85 ± 0.03, and 0.90 ± 0.03. Conclusions Kinetics of inhaled anesthetic washin and washout are substantially altered by changes in the global VA/Q ratio for normal lungs. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Purpose: Remote ischemic preconditioning (RIP) may protect remote organs from ischemia-reperfusion-injury (IRI) in surgical and non-surgical patients. There are few data available on RIP and lung function, especially not in healthy volunteers. The null-hypothesis was tested that RIP does not have an effect on pulmonary function when applied on healthy volunteers that were breathing spontaneously and did not experience any intervention. After approval of the Ethics Committee and informed consent of the study subjects, 28 healthy non-smoking volunteers were included and randomized in either the RIP group (n = 13) or the control group (n = 15). In the RIP group, lower limb ischemia was induced by inflation of a blood pressure cuff to a pressure 20 mmHg above the systolic blood pressure. After five minutes the blood pressure cuff was released for five minutes rest. The procedure was repeated three times resulting in 40 min ischemia and reperfusion. Capillary blood samples were taken, and lung function tests were performed at baseline (T1) and 60 min (T2) and 24 h (T3) after RIP. The control group was treated in the same fashion, but the RIP procedure was replaced by a sham protocol. Results: 60 min after RIP capillary pO(2) decreased significantly and returned to baseline level after 24 h in the RIP group. This did not occur in the control group. Capillary pCO(2), variables of lung function tests and pulmonary capillary blood volume remained unchanged throughout the experiment in both groups. Conclusion. Oxygenation is impaired early after RIP which is possibly induced by transient ventilation-perfusion inequality. No late effects of RIP were observed. The null hypothesis has to be rejected that RIP has no effect on respiratory variables in healthy volunteers.

BACKGROUND:Remote ischemic preconditioning (RIP) may protect target organs from ischemia - reperfusion injury, however, little is known on pulmonary effects of RIP prior to, immediately after and several hours after one-lung ventilation (OLV). The present randomized, controlled, animal experiment was undertaken to analyze these issues. METHODS:After animal ethics committee approval, twelve piglets (26 ± 2 kg) were anesthetized and randomly assigned to a control (n = 6) or to a RIP group (n = 6). For RIP, arterial perfusion of a hind limb was suspended by an inflated blood pressure cuff (200 mmHg for 5 min) and deflated for another 5 min, this was repeated four times. After intubation, mechanical ventilation (MV) was kept constant with tidal volume 10 ml/kg, inspired oxygen fraction (FIO2) 0.40, and positive end-expiratory pressure (PEEP) 5cmH2O. FIO2 was increased to 1 after RIP in the RIP group and after the sham procedure in the control group, respectively, for the time of OLV. OLV was established by left-sided bronchial blockade. After OLV, TLV was re-established until the end of the protocol. Exhaled nitric oxide (NO) was measured by ozon chemiluminiscense and ventilatory and hemodynamic variables were assessed according to the protocol. RESULTS:Hemodynamic and respiratory data were similar in both groups. Arterial pO2 was higher in the RIP group after two hours of OLV. In the control group, exhaled NO decreased during OLV and remained at low levels for the rest of the protocol. In the RIP group, exhaled NO decreased as well during OLV but returned to baseline levels when TLV was re-established. CONCLUSIONS:RIP has no effects on hemodynamic and respiratory variables in juvenile, healthy piglets. RIP improves the oxygenation after OLV and prevents the decline of exhaled NO after OLV.

Purpose of Review Remote ischemic preconditioning (RIP) has been demonstrated to protect against ischemia-reperfusion-injury in different target organs. The mechanisms that eventually lead to these protective effects have been investigated in depth but are not yet fully elucidated. Although the effects of RIP seem to be promising in animal experiments and smaller clinical studies, they failed to achieve clinical significance in multicenter trials. These trials have mainly focused on the heart, the brain, and the kidneys, but only little is known concerning the effects of RIP on the lungs. This review will provide an overview on what is already published on RIP and its effects on the respiratory system. Recent Findings Different modes of RIP action have been assessed, like systemic, humoral, and neural responses. As mechanical ventilation, and especially one-lung ventilation, is harmful to the lungs, it is of great interest to find ways of protecting the respiratory system in clinical practice. Therefore, experimental as well as clinical trials have been performed to seek for protective devices. Summary RIP is easy to perform and cheap to apply and is therefore a promising and interesting tool that might find its way into clinical practice in order to attenuate the detrimental effects of mechanical ventilation to the lungs. The present review will highlight and discuss recent experimental data especially on pulmonary effects of RIP.

The aim of our study was the identification of genetic variants associated with postoperative complications after cardiac surgery. We conducted a prospective, double-blind, multicenter, randomized trial (RIPHeart). We performed a genome-wide association study (GWAS) in 1170 patients of both genders (871 males, 299 females) from the RIPHeart-Study cohort. Patients undergoing non-emergent cardiac surgery were included. Primary endpoint comprises a binary composite complication rate covering atrial fibrillation, delirium, non-fatal myocardial infarction, acute renal failure and/or any new stroke until hospital discharge with a maximum of fourteen days after surgery. A total of 547,644 genotyped markers were available for analysis. Following quality control and adjustment for clinical covariate, one SNP reached genome-wide significance (PHLPP2, rs78064607, p = 3.77 × 10− 8) and 139 (adjusted for all other outcomes) SNPs showed promising association with p < 1 × 10− 5 from the GWAS. We identified several potential loci, in particular PHLPP2, BBS9, RyR2, DUSP4 and HSPA8, associated with new-onset of atrial fibrillation, delirium, myocardial infarction, acute kidney injury and stroke after cardiac surgery. The study was registered with ClinicalTrials.gov NCT01067703, prospectively registered on 11 Feb 2010.

Background Remote ischemic preconditioning ( RIPC ) has been suggested to protect against certain forms of organ injury after cardiac surgery. Previously, we reported the main results of RIPHeart (Remote Ischemic Preconditioning for Heart Surgery) Study, a multicenter trial randomizing 1403 cardiac surgery patients receiving either RIPC or sham‐ RIPC . Methods and Results In this follow‐up paper, we present 1‐year follow‐up of the composite primary end point and its individual components (all‐cause mortality, myocardial infarction, stroke and acute renal failure), in a sub‐group of patients, intraoperative myocardial dysfunction assessed by transesophageal echocardiography and the incidence of postoperative neurocognitive dysfunction 5 to 7 days and 3 months after surgery. RIPC neither showed any beneficial effect on the 1‐year composite primary end point ( RIPC versus sham‐ RIPC 16.4% versus 16.9%) and its individual components (all‐cause mortality [3.4% versus 2.5%], myocardial infarction [7.0% versus 9.4%], stroke [2.2% versus 3.1%], acute renal failure [7.0% versus 5.7%]) nor improved intraoperative myocardial dysfunction or incidence of postoperative neurocognitive dysfunction 5 to 7 days (67 [47.5%] versus 71 [53.8%] patients) and 3 months after surgery (17 [27.9%] versus 18 [27.7%] patients), respectively. Conclusions Similar to our main study, RIPC had no effect on intraoperative myocardial dysfunction, neurocognitive function and long‐term outcome in cardiac surgery patients undergoing propofol anesthesia. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT 01067703.