Teleconsultation for Preoperative Anesthesia Evaluation: Identifying Environmental Potentials by Life Cycle Assessment.

Introduction: Teleconsultations for preoperative evaluation in anesthesiology proved to be feasible during the COVID-19 pandemic. However, widespread implementation of teleconsultations has not yet occurred. Besides time savings and economic benefits, teleconsultations in anesthesia may have the potential to reduce CO2 emissions. Methods: We conducted a life cycle assessment based on prospective surveys to assess the potential environmental benefits of preoperative anesthesia teleconsultations in comparison to the status-quo in-person consultations. Within 1 month, all patients presenting at the preoperative anesthesia clinic at RWTH Aachen University Hospital were asked about the distance traveled and mode of transportation to the hospital. The main outcome measure was the potential environmental benefit resulting from the implementation of teleconsultations. Results: In total, 821 out of 981 patients presenting at the anesthesia clinic participated in the survey. Most patients visited on an outpatient basis (62.9%) and traveled by car (81.7%). The median travel distance was 25 km [interquartile range 12-40]. If patients who came to the hospital solely for the anesthesia appointment had scheduled virtual appointments, the emissions of 3.03-ton CO2 equivalents (CO2-eq) could be avoided in the first month after implementation. The environmental impact associated with the production of teleconsultation equipment is outweighed by the reduction in patient travel. If all outpatient appointments were performed virtually, these savings would triple. Within 10 years, more than 1,300 tons CO2-eq could be avoided. Conclusion: Teleconsultations can mitigate the environmental impact of in-person anesthesia consultations. Further research is essential to leverage teleconsultations for preoperative evaluation also across other medical specialties.

Inhaled nitric oxide preserves ventricular function during resuscitation using a percutaneous mechanical circulatory support device in a porcine cardiac arrest model: an echocardiographic myocardial work analysis.

BACKGROUND: Resuscitation using a percutaneous mechanical circulatory support device (iCPR) improves survival after cardiac arrest (CA). We hypothesized that the addition of inhaled nitric oxide (iNO) during iCPR might prove synergistic, leading to improved myocardial performance due to lowering of right ventricular (RV) afterload, left ventricular (LV) preload, and myocardial energetics. This study aimed to characterize the changes in LV and RV function and global myocardial work indices (GWI) following iCPR, both with and without iNO, using 2-D transesophageal echocardiography (TEE) and GWI evaluation as a novel non-invasive measurement. METHODS: In 10 pigs, iCPR was initiated following electrically-induced CA and 10 min of untreated ventricular fibrillation (VF). Pigs were randomized to either 20 ppm (20 ppm, n = 5) or 0 ppm (0 ppm, n = 5) of iNO in addition to therapeutic hypothermia for 5 h following ROSC. All animals received TEE at five pre-specified time-points and invasive hemodynamic monitoring. RESULTS: LV end-diastolic volume (LVEDV) increased significantly in both groups following CA. iCPR alone led to significant LV unloading at 5 h post-ROSC with LVEDV values reaching baseline values in both groups (20 ppm: 68.2 ± 2.7 vs. 70.8 ± 6.1 mL, p = 0.486; 0 ppm: 70.8 ± 1.3 vs. 72.3 ± 4.2 mL, p = 0.813, respectively). LV global longitudinal strain (GLS) increased in both groups following CA. LV-GLS recovered significantly better in the 20 ppm group at 5 h post-ROSC (20 ppm: - 18 ± 3% vs. 0 ppm: - 13 ± 2%, p = 0.025). LV-GWI decreased in both groups after CA with no difference between the groups. Within 0 ppm group, LV-GWI decreased significantly at 5 h post-ROSC compared to baseline (1,125 ± 214 vs. 1,835 ± 305 mmHg%, p = 0.011). RV-GWI was higher in the 20 ppm group at 3 h and 5 h post-ROSC (20 ppm: 189 ± 43 vs. 0 ppm: 108 ± 22 mmHg%, p = 0.049 and 20 ppm: 261 ± 54 vs. 0 ppm: 152 ± 42 mmHg%, p = 0.041). The blood flow calculated by the Impella controller following iCPR initiation correlated well with the pulsed-wave Doppler (PWD) derived pulmonary flow (PWD vs. controller: 1.8 ± 0.2 vs. 1.9 ± 0.2L/min, r = 0.85, p = 0.012). CONCLUSIONS: iCPR after CA provided sufficient unloading and preservation of the LV systolic function by improving LV-GWI recovery. The addition of iNO to iCPR enabled better preservation of the RV-function as determined by better RV-GWI. Additionally, Impella-derived flow provided an accurate measure of total flow during iCPR.

Teleconsultation for preoperative evaluation during the coronavirus disease 2019 pandemic: A technical and medical feasibility study.

BACKGROUND: During the surge in coronavirus disease 2019 (COVID-19) infections in early 2020, many medical organisations began developing strategies for implementing teleconsultation to maintain medical services during lockdown and to limit physical contact. Therefore, we developed a teleconsultation preoperative evaluation platform to replace on-site preoperative meetings. OBJECTIVE: This study assessed the feasibility of a teleconsultation for preoperative evaluation and procedure-associated adverse events. DESIGN: Implementation study. SETTING: A tertiary care university hospital in Germany from April 2020 to October 2020. PATIENTS: One hundred and eleven patients scheduled for elective surgery. INTERVENTION: Patients were assigned to receive teleconsultation for preoperative evaluation and to complete a subsequent survey. MAIN OUTCOME MEASURES: Primary endpoints were medical and technical feasibility, user satisfaction and time savings. RESULTS: For 100 out of 111 patients, telepreoperative consultations allowed for adequate perioperative risk assessment, patient education and also for effective collection of legal signatures. For six patients (5.4%), consultations could not be started because of technical issues, whereas for five patients (4.8%), clearance for surgery could not be granted because of medical reasons. A clear majority of anaesthetists (93.7%) rated the telepreoperative evaluations as equivalent to on-site meetings. The majority of the patients considered teleconsultation for preoperative evaluation as convenient as an on-site meeting (98.2%) and would choose a teleconsultation again (97.9%). Median travel time saved by patients was 60 min (Q1 40, Q3 80). We registered one adverse event: we detected atrial fibrillation in one patient only immediately prior to surgery. CONCLUSION: Telepreoperative evaluations are medically and technically feasible, yielding high satisfaction rates on both sides. However, regarding patient safety, not every patient is equally well suited. Overall, implementation of teleconsultation for preoperative evaluation into clinical routine could help maintain medical care during the COVID-19 pandemic. TRIAL REGISTRATION: NCT04518514, ClinicalTrials.gov.

Brief inhalation of nitric oxide increases resuscitation success and improves 7-day-survival after cardiac arrest in rats: a randomized controlled animal study.

INTRODUCTION: Inhaled nitric oxide (iNO) improves outcomes when given post systemic ischemia/reperfusion injury. iNO given during cardiopulmonary resuscitation (CPR) may therefore improve return of spontaneous circulation (ROSC) rates and functional outcome after cardiac arrest (CA). METHODS: Thirty male Sprague-Dawley rats were subjected to 10 minutes of CA and at least 3 minutes of CPR. Animals were randomized to receive either 0 (n = 10, Control), 20 (n = 10, 20 ppm), or 40 (n = 10, 40 ppm) ppm iNO during CPR until 30 minutes after ROSC. A neurological deficit score was assessed daily for seven days following the experiment. On day 7, brains, hearts, and blood were sampled for histological and biochemical evaluation. RESULTS: During CPR, 20 ppm iNO significantly increased diastolic arterial pressure ( CONTROL: 57 ± 5.04 mmHg; 20 ppm: 71.57 ± 57.3 mmHg, p < 0.046) and decreased time to ROSC (CONTROL: 842 ± 21 s; 20 ppm: 792 ± 5 s, (p = 0.02)). Thirty minutes following ROSC, 20 ppm iNO resulted in an increase in mean arterial pressure ( CONTROL: 83 ± 4 mmHg; 20 ppm: 98 ± 4 mmHg, p = 0.035), a less pronounced rise in lactate and inflammatory cytokine levels, and attenuated cardiac damage. Inhalation of NO at 20 ppm improved neurological outcomes in rats 2 to 7 days after CA and CPR. This translated into increases in 7 day survival ( CONTROL: 4; 20 ppm: 10; 40 ppm 6, (p ≤ 0.05 20 ppm vs CONTROL and 40 ppm). CONCLUSIONS: Our study revealed that breathing NO during CPR markedly improved resuscitation success, 7-day neurological outcomes and survival in a rat model of VF-induced cardiac arrest and CPR. These results support the beneficial effects of NO inhalation after cardiac arrest and CPR.

Inhaled nitric oxide improves transpulmonary blood flow and clinical outcomes after prolonged cardiac arrest: a large animal study.

INTRODUCTION: The probability to achieve a return of spontaneous circulation (ROSC) after cardiac arrest can be improved by optimizing circulation during cardiopulomonary resuscitation using a percutaneous left ventricular assist device (iCPR). Inhaled nitric oxide may facilitate transpulmonary blood flow during iCPR and may therefore improve organ perfusion and outcome. METHODS: Ventricular fibrillation was electrically induced in 20 anesthetized male pigs. Animals were left untreated for 10 minutes before iCPR was attempted. Subjects received either 20 ppm of inhaled nitric oxide (iNO, n = 10) or 0 ppm iNO (Control, n = 10), simultaneously started with iCPR until 5 hours following ROSC. Animals were weaned from the respirator and followed up for five days using overall performance categories (OPC) and a spatial memory task. On day six, all animals were anesthetized again, and brains were harvested for neurohistopathologic evaluation. RESULTS: All animals in both groups achieved ROSC. Administration of iNO markedly increased iCPR flow during CPR (iNO: 1.81 ± 0.30 vs CONTROL: 1.64 ± 0.51 L/min, p < 0.001), leading to significantly higher coronary perfusion pressure (CPP) during the 6 minutes of CPR (25 ± 13 vs 16 ± 6 mmHg, p = 0.002). iNO-treated animals showed significantly lower S-100 serum levels thirty minutes post ROSC (0.26 ± 0.09 vs 0.38 ± 0.15 ng/mL, p = 0.048), as well as lower blood glucose levels 120-360 minutes following ROSC. Lower S-100 serum levels were reflected by superior clinical outcome of iNO-treated animals as estimated with OPC (3 ± 2 vs. 5 ± 1, p = 0.036 on days 3 to 5). Three out of ten iNO-treated, but none of the CONTROL animals were able to successfully participate in the spatial memory task. Neurohistopathological examination of vulnerable cerebral structures revealed a trend towards less cerebral lesions in neocortex, archicortex, and striatum in iNO-treated animals compared to CONTROLs. CONCLUSIONS: In pigs resuscitated with mechanically-assisted CPR from prolonged cardiac arrest, the administration of 20 ppm iNO during and following iCPR improved transpulmonary blood flow, leading to improved clinical neurological outcomes.

Doubling survival and improving clinical outcomes using a left ventricular assist device instead of chest compressions for resuscitation after prolonged cardiac arrest: a large animal study.

INTRODUCTION: Despite improvements in pre-hospital and post-arrest critical care, sudden cardiac arrest (CA) remains one of the leading causes of death. Improving circulation during cardiopulmonary resuscitation (CPR) may improve survival rates and long-term clinical outcomes after CA. METHODS: In a porcine model, we compared standard CPR (sCPR; n =10) with CPR using an intravascular cardiac assist device without additional chest compressions (iCPR; n =10) following 10 minutes of electrically induced ventricular fibrillation (VF). In a separate crossover experiment, 10 additional pigs were subjected to 10 minutes of VF and 6 minutes of sCPR; the iCPR device was then implanted if a return of spontaneous circulation (ROSC) was not achieved using sCPR. Animals were evaluated in respect to intra- and post-arrest hemodynamics, survival, functional outcome and cerebral and myocardial lesions following CPR. We hypothesized that iCPR would result in more frequent ROSC and better functional recovery than sCPR. RESULTS: iCPR produced a mean flow of 1.36 ± 0.02 L/min, leading to significantly higher coronary perfusion pressure (CPP) values during the early period of CPR (22 ± 10 mmHg vs. 9 ± 5 mmHg, P ≤0.01, 1 minute after start of CPR; 20 ± 11 mmHg vs. 10 ± 7 mmHg, P =0.03, 2 minutes after start of CPR), resulting in high ROSC rates (100% in iCPR vs. 50% in sCPR animals; P =0.03). iCPR animals showed significantly lower serum S100 levels at 10 and 30 minutes following ROSC (3.5 ± 0.6 ng/ml vs. 7.4 ± 3.0 ng/ml 30 minutes after ROSC; P ≤0.01), as well as superior clinical outcomes based on overall performance categories (2.9 ± 1.0 vs. 4.6 ± 0.8 on day 1; P ≤0.01). In crossover experiments, 80% of animals required treatment with iCPR after failed sCPR. Notably, ROSC was still achieved in six of the remaining eight animals (75%) after a total of 22.8 ± 5.1 minutes of ischemia. CONCLUSIONS: In a model of prolonged cardiac arrest, the use of iCPR instead of sCPR improved CPP and doubled ROSC rates, translating into improved clinical outcomes.

Delayed argon administration provides robust protection against cardiac arrest-induced neurological damage.

INTRODUCTION: Argon at a dosage of 70 % is neuroprotective, when given 1 h after cardiac arrest (CA) in rats. We investigated if a neuroprotective effect of argon would also be observed, when administration was delayed. METHODS: Twenty-four male Sprague-Dawley rats, weighing between 400 and 500 g were subjected to 7 min of CA and 3 min of cardiopulmonary resuscitation. Animals were randomized to receive either 1 h of 70 % argon ventilation 1 h (n = 8) or 3 h (n = 8) after return of spontaneous circulation or no argon treatment (n = 8). For all animals, a neurological deficit score (NDS) was calculated daily for 7 days following the experiment. On day 8, rats were re-anesthetized and transcardially perfused before brains were harvested for histopathological analyses. RESULTS: All animals survived. Control animals exhibited severe neurologic dysfunction at all time points as measured with the NDS. Argon-treated animals showed significant improvements in the NDS through all postoperative days, even when argon administration was delayed for 3 h. This was paralleled by a significant reduction in the neuronal damage index in the neocortex and the hippocampal CA 3/4 region in argon-treated animals, regardless of the timing of argon administration. However, animals of the delayed argon administration group additionally showed significant reductions in the basal ganglia in comparison with control animals. CONCLUSION: Our study demonstrates that a 1-h application of argon provided a significant reduction in histopathological damage, associated with a marked improvement in functional neurologic recovery even when treatment was delayed for 3 h. This is highly significant with regard to clinical situations, where argon treatment cannot be provided timely.

The Self-Expandable Impella CP (ECP) as a Mechanical Resuscitation Device.

The survival rate of cardiac arrest (CA) can be improved by utilizing percutaneous left ventricular assist devices (pLVADs) instead of conventional chest compressions. However, existing pLVADs require complex fluoroscopy-guided placement along a guidewire and suffer from limited blood flow due to their cross-sectional area. The recently developed self-expandable Impella CP (ECP) pLVAD addresses these limitations by enabling guidewire-free placement and increasing the pump cross-sectional area. This study evaluates the feasibility of resuscitation using the Impella ECP in a swine CA model. Eleven anesthetized pigs (73.8 ± 1.7 kg) underwent electrically induced CA, were left untreated for 5 min and then received pLVAD insertion and activation. Vasopressors were administered and defibrillations were attempted. Five hours after the return of spontaneous circulation (ROSC), the pLVAD was removed, and animals were monitored for an additional hour. Hemodynamics were assessed and myocardial function was evaluated using echocardiography. Successful guidewire-free pLVAD placement was achieved in all animals. Resuscitation was successful in 75% of cases, with 3.5 ± 2.0 defibrillations and 1.8 ± 0.4 mg norepinephrine used per ROSC. Hemodynamics remained stable post-device removal, with no adverse effects or aortic valve damage observed. The Impella ECP facilitated rapid guidewire-free pLVAD placement in fibrillating hearts, enabling successful resuscitation. These findings support a broader clinical adoption of pLVADs, particularly the Impella ECP, for CA.

Comparing Charlson Comorbidity Index Scores between Anesthesiologists, Patients, and Administrative Data: A Prospective Observational Study.

(1) Background: Patients' comorbidities play an immanent role in perioperative risk assessment. It is unknown how Charlson Comorbidity Indices (CCIs) from different sources compare. (2) Methods: In this prospective observational study, we compared the CCIs of patients derived from patients' self-reports and from physicians' assessments with hospital administrative data. (3) Results: The data of 1007 patients was analyzed. Agreement between the CCI from patients' self-report compared to administrative data was fair (kappa 0.24 [95%CI 0.2-0.28]). Agreement between physicians' assessment and the administrative data was also fair (kappa 0.28 [95%CI 0.25-0.31]). Physicians' assessment and patients' self-report had the best agreement (kappa 0.33 [95%CI 0.30-0.37]). The CCI calculated from the administrative data showed the best predictability for in-hospital mortality (AUROC 0.86 [95%CI 0.68-0.91]), followed by equally good prediction from physicians' assessment (AUROC 0.80 [95%CI 0.65-0.94]) and patients' self-report (AUROC 0.80 [95%CI 0.75-0.97]). (4) Conclusions: CCIs derived from patients' self-report, physicians' assessments, and administrative data perform equally well in predicting postoperative in-hospital mortality.

Inhibition of bone morphogenetic protein signaling reduces vascular calcification and atherosclerosis.

OBJECTIVE: The expression of bone morphogenetic proteins (BMPs) is enhanced in human atherosclerotic and calcific vascular lesions. Although genetic gain- and loss-of-function experiments in mice have supported a causal role of BMP signaling in atherosclerosis and vascular calcification, it remains uncertain whether BMP signaling might be targeted pharmacologically to ameliorate both of these processes. METHODS AND RESULTS: We tested the impact of pharmacological BMP inhibition on atherosclerosis and calcification in LDL receptor-deficient (LDLR-/-) mice. LDLR-/- mice fed a high-fat diet developed abundant vascular calcification within 20 weeks. Prolonged treatment of LDLR-/- mice with the small molecule BMP inhibitor LDN-193189 was well-tolerated and potently inhibited development of atheroma, as well as associated vascular inflammation, osteogenic activity, and calcification. Administration of recombinant BMP antagonist ALK3-Fc replicated the antiatherosclerotic and anti-inflammatory effects of LDN-193189. Treatment of human aortic endothelial cells with LDN-193189 or ALK3-Fc abrogated the production of reactive oxygen species induced by oxidized LDL, a known early event in atherogenesis. Unexpectedly, treatment of mice with LDN-193189 lowered LDL serum cholesterol by 35% and markedly decreased hepatosteatosis without inhibiting HMG-CoA reductase activity. Treatment with BMP2 increased, whereas LDN-193189 or ALK3-Fc inhibited apolipoprotein B100 secretion in HepG2 cells, suggesting that BMP signaling contributes to the regulation of cholesterol biosynthesis. CONCLUSION: These results definitively implicate BMP signaling in atherosclerosis and calcification, while uncovering a previously unidentified role for BMP signaling in LDL cholesterol metabolism. BMP inhibition may be helpful in the treatment of atherosclerosis and associated vascular calcification.

[Teleconsultation for preoperative evaluation and informed consent-Are we ready for a paradigm shift?] / Anästhesiologische Risikoevaluation und rechtssichere Aufklärung per Telemedizin ­ Sind wir bereit für einen Paradigmenwechsel?

In Germany, approximately 17 million anaesthesiological procedures and, consequently, roughly the same number of preoperative consultations are conducted each year. So far, these have predominantly taken place in person. However, recent developments in technology, medical-legal aspects, and politics, combined with the catalyzing effect of the pandemic situation, have led to a significant boost in telemedicine. In the field of anaesthesia, there are new approaches to implementing telemedicine in the pre- and postoperative setting. This article focuses on the preoperative setting and presents general requirements for a teleconsultation as preoperative evaluation, the current state of technology, and medical-legal aspects.

Combining xenon and mild therapeutic hypothermia preserves neurological function after prolonged cardiac arrest in pigs.

OBJECTIVE: Despite the introduction of mild therapeutic hypothermia into postcardiac arrest care, cerebral and myocardial injuries represent the limiting factors for survival after cardiac arrest. Administering xenon may confer an additional neuroprotective effect after successful cardiopulmonary resuscitation due to its ability to stabilize cellular calcium homeostasis via N-methyl-D-aspartate-receptor antagonism. DESIGN: In a porcine model, we evaluated effects of xenon treatment in addition to therapeutic hypothermia on neuropathologic and functional outcomes after cardiopulmonary resuscitation. SETTING: Prospective, randomized, laboratory animal study. SUBJECTS: Fifteen male pigs. INTERVENTIONS: Following 10 mins of cardiac arrest and 6 mins of cardiopulmonary resuscitation, ten pigs were randomized to receive either mild therapeutic hypothermia (33°C for 16 hrs) or mild therapeutic hypothermia 1 xenon (70% for 1 hr). Five animals served as normothermic controls. MEASUREMENTS AND MAIN RESULTS: Gross hemodynamic variables were measured using right-heart catheterization. Neurocognitive performance was evaluated for 5 days after cardiopulmonary resuscitation using a neurologic deficit score before the brains were harvested for histopathological analysis. All animals survived the observation period in the mild therapeutic hypothermia 1 xenon group while one animal in each of the other two groups died. Mild therapeutic hypothermia 1 xenon preserved cardiac output during the induction of mild therapeutic hypothermia significantly better than did mild therapeutic hypothermia alone (4.6 6 0.6 L/min vs. 3.2 6 1.6 L/min, p # .05). Both treatment groups showed significantly fewer necrotic lesions in the cerebral cortex, caudate nucleus, putamen, and in hippocampal sectors CA1 and CA3/4. However, only the combination of mild therapeutic hypothermia and xenon resulted in reduced astrogliosis in the CA1 sector and diminished microgliosis and perivascular inflammation in the putamen. Clinically, only the mild therapeutic hypothermia 1 xenon-treated animals showed significantly improved neurologic deficit scores over time (day 1 = 59.0 6 27.0 vs. day 5 = 4.0 6 5.5, p ø .05) as well as in comparison to the untreated controls on days 3 through 5 after cardiopulmonary resuscitation. CONCLUSIONS: These results demonstrate that even a short exposure to xenon during induction of mild therapeutic hypothermia results in significant improvements in functional recovery and ameliorated myocardial dysfunction.

Administration of hydrogen sulfide via extracorporeal membrane lung ventilation in sheep with partial cardiopulmonary bypass perfusion: a proof of concept study on metabolic and vasomotor effects.

INTRODUCTION: Although inhalation of 80 parts per million (ppm) of hydrogen sulfide (H2S) reduces metabolism in mice, doses higher than 200 ppm of H2S were required to depress metabolism in rats. We therefore hypothesized that higher concentrations of H2S are required to reduce metabolism in larger mammals and humans. To avoid the potential pulmonary toxicity of H2S inhalation at high concentrations, we investigated whether administering H2S via ventilation of an extracorporeal membrane lung (ECML) would provide means to manipulate the metabolic rate in sheep. METHODS: A partial venoarterial cardiopulmonary bypass was established in anesthetized, ventilated (fraction of inspired oxygen = 0.5) sheep. The ECML was alternately ventilated with air or air containing 100, 200, or 300 ppm H2S for intervals of 1 hour. Metabolic rate was estimated on the basis of total CO2 production (VCO2) and O2 consumption (VO2). Continuous hemodynamic monitoring was performed via indwelling femoral and pulmonary artery catheters. RESULTS: VCO2, VO2, and cardiac output ranged within normal physiological limits when the ECML was ventilated with air and did not change after administration of up to 300 ppm H2S. Administration of 100, 200 and 300 ppm H2S increased pulmonary vascular resistance by 46, 52 and 141 dyn·s/cm5, respectively (all P ≤ 0.05 for air vs. 100, 200 and 300 ppm H2S, respectively), and mean pulmonary artery pressure by 4 mmHg (P ≤ 0.05), 3 mmHg (n.s.) and 11 mmHg (P ≤ 0.05), respectively, without changing pulmonary capillary wedge pressure or cardiac output. Exposure to 300 ppm H2S decreased systemic vascular resistance from 1,561 ± 553 to 870 ± 138 dyn·s/cm(5) (P ≤ 0.05) and mean arterial pressure from 121 ± 15 mmHg to 66 ± 11 mmHg (P ≤ 0.05). In addition, exposure to 300 ppm H2S impaired arterial oxygenation (PaO2 114 ± 36 mmHg with air vs. 83 ± 23 mmHg with H2S; P ≤ 0.05). CONCLUSIONS: Administration of up to 300 ppm H2S via ventilation of an extracorporeal membrane lung does not reduce VCO2 and VO2, but causes dose-dependent pulmonary vasoconstriction and systemic vasodilation. These results suggest that administration of high concentrations of H2S in venoarterial cardiopulmonary bypass circulation does not reduce metabolism in anesthetized sheep but confers systemic and pulmonary vasomotor effects.

Safety and quality of perioperative anesthesia care-Ensuring safe care for older people living with frailty.

The clinical concept of frailty as a detectable and improvable clinical condition has emerged in the field of geriatric medicine over the past two decades. Albeit frailty can be described as the rapid deterioration of organ function during the physiological aging process, this syndrome is not exclusively limited to the elderly. Recently, this concept has been introduced in the field of anesthesia and critical care as a means to better appraise perioperative risks and offer patient-centered individual treatment pathways. Extensive efforts have been invested into the research on tools for the detection and quantification of frailty. However, while multiple tools have been validated for the detection of frailty in different populations, no universal score or test has been validated to be universally applicable. Furthermore, it is unclear whether interventions capable of improving the detected degree of frailty may result in better outcomes. Ongoing and future research is aimed at developing automated systems that help in harnessing standard medical records for reliable frailty screening without additional user input. Further efforts are pointed at understanding the potential reversibility of frailty through interventions such as exercise or nutritional supplements. While the role of frailty detection, quantification, and treatment in anesthesia and critical care is limited today, it is likely that it may become a key element of perioperative care of older patients in the near future.

Transesophageal echocardiography in swine: evaluation of left and right ventricular structure, function and myocardial work.

This study aimed to determine standard left (LV) and right ventricular (RV) transesophageal echocardiographic (TEE) measurements in swine. Additionally, global myocardial work index (GWI) was estimated using pressure-strain loops (PSL). A comprehensive TEE examination was conducted in ten anesthetized, intubated and mechanically ventilated healthy female German landrace swine, weighing 44 to 57 kg. For GWI calculation, we performed LV and RV segmental strain analysis and used invasively measured LV and RV pressure to obtain PSL. The GWI and further myocardial work indices were calculated from the area of the PSL using commercially available software. Furthermore, hemodynamic measurements were obtained using indwelling catheters. We obtained complete standardized baseline values for left and right ventricular dimensions and function. Biplane LV ejection fraction was 63 ± 7 % and the LV end-diastolic volume was 70.5 ± 5.9 ml. Tissue Doppler estimated peak tricuspid annular systolic velocity was 13.1 ± 1.8 cm/s. The Doppler estimated LV and RV stroke volume index were 75.6 ± 7.2 ml/m2 and 76.7 ± 7.8 ml/m2 respectively. Pulsed wave Doppler derived cardiac output correlated well with cardiac output estimated using the thermodilution method (7.0 ± 1.2 l/min vs. 7.0 ± 1.1 l/min, r = 0.812, p = 0.004). The LV global longitudinal strain was -21.3 ± 3.9 % and the RV global longitudinal strain was -15.4 ± 2.5 %. LV GWI was 1885(1281-2121) mmHg*% and 297 ± 62 mmHg*% for the RV. LV global myocardial work efficiency was 82.6 ± 4 % and 83(72-88) % for the RV. TEE offers sufficient morphological, functional and hemodynamic assessment of the heart in swine. Myocardial contractility and mechanics can be reliably evaluated with the non-invasive GWI derived from echocardiography without additional invasive measures.

Changes in S-100 protein serum levels in survivors of out-of-hospital cardiac arrest treated with mild therapeutic hypothermia: a prospective, observational study.

INTRODUCTION: Knowledge about the influence of current neuroprotective interventions on prognostic markers after survival from cardiac arrest is lacking. This study aimed to investigate the effects of mild therapeutic hypothermia on the release of the astroglial protein S-100 after cardiopulmonary resuscitation (CPR) in survivors of out-of-hospital cardiac arrest. METHODS: This was a prospective, observational study performed during a two-year period, involving medical emergency services and five collaborating hospitals at the city of Aachen, Germany. Sixty-eight subjects were enrolled by the emergency physician on duty by taking blood samples after successful attempts at resuscitation with return of spontaneous circulation (ROSC), followed by samples at 6, 12, 24, 72 and 120 hours post ROSC by the appropriate intensive care unit staff. Depending on the decision of the attending physician, subjects were cooled down to 33 degrees C (n = 37) for 24 hours or were held at 37 degrees C (n = 31). Patients were tracked for estimating mortality and gross neurological outcome for 14 days. RESULTS: S-100 levels in patients not receiving mild therapeutic hypothermia (normothermia (NT)) showed equivalent numbers as compared with cooled patients (mild therapeutic hypothermia (MTH)) on baseline (NT = 1.38 mug/l versus MTH = 1.30 microg/l; P = 0.886). S-100 levels on baseline were significantly lower in patients with a good neurological outcome at 14 days after the event in comparison to their peers with adverse outcome (P = 0.014). Although the difference in S-100 levels of MTH patients with adverse or favourable neurological outcome reached statistical significance, it did not in NT patients. CONCLUSIONS: Although the predictive power of S-100 levels were best on admission but not at later time points, MTH had no influence on S-100 serum levels in survivors of non-traumatic out-of-hospital cardiac arrest in the particular setting of this investigation.

The intuitive use of laryngeal airway tools by first year medical students.

BACKGROUND: Providing a secured airway is of paramount importance in cardiopulmonary resuscitation. Although intubating the trachea is yet seen as gold standard, this technique is still reserved to experienced healthcare professionals. Compared to bag-valve facemask ventilation, however, the insertion of a laryngeal mask airway offers the opportunity to ventilate the patient effectively and can also be placed easily by lay responders. Obviously, it might be inserted without detailed background knowledge.The purpose of the study was to investigate the intuitive use of airway devices by first-year medical students as well as the effect of a simple, but well-directed training programme. Retention of skills was re-evaluated six months thereafter. METHODS: The insertion of a LMA-Classic and a LMA-Fastrach performed by inexperienced medical students was compared in an airway model. The improvement on their performance after a training programme of overall two hours was examined afterwards. RESULTS: Prior to any instruction, mean time to correct placement was 55.5 +/- 29.6 s for the LMA-Classic and 38.1 +/- 24.9 s for the LMA-Fastrach. Following training, time to correct placement decreased significantly with 22.9 +/- 13.5 s for the LMA-Classic and 22.9 +/- 19.0 s for the LMA-Fastrach, respectively (p < 0.05). After six months, the results are comparable prior (55.6 +/- 29.9 vs 43.1 +/- 34.7 s) and after a further training period (23.5 +/- 13.2 vs 26.6 +/- 21.6, p < 0.05). CONCLUSION: Untrained laypersons are able to use different airway devices in a manikin and may therefore provide a secured airway even without having any detailed background knowledge about the tool. Minimal theoretical instruction and practical skill training can improve their performance significantly. However, refreshment of knowledge seems justified after six months.

The Septic Heart: Current Understanding of Molecular Mechanisms and Clinical Implications.

Septic cardiomyopathy is a key feature of sepsis-associated cardiovascular failure. Despite the lack of consistent diagnostic criteria, patients typically exhibit ventricular dilatation, reduced ventricular contractility, and/or both right and left ventricular dysfunction with a reduced response to volume infusion. Although there is solid evidence that the presence of septic cardiomyopathy is a relevant contributor to organ dysfunction and an important factor in the already complicated therapeutic management of patients with sepsis, there are still several questions to be asked: Which factors/mechanisms cause a cardiac dysfunction associated with sepsis? How do we diagnose septic cardiomyopathy? How do we treat septic cardiomyopathy? How does septic cardiomyopathy influence the long-term outcome of the patient? Each of these questions is interrelated, and the answers require a profound understanding of the underlying pathophysiology that involves a complex mix of systemic factors and molecular, metabolic, and structural changes of the cardiomyocyte. The afterload-related cardiac performance, together with speckle-tracking echocardiography, could provide methods to improve the diagnostic accuracy and guide therapeutic strategies in patients with septic cardiomyopathy. Because there are no specific/causal therapeutics for the treatment of septic cardiomyopathy, the current guidelines for the treatment of septic shock represent the cornerstone of septic cardiomyopathy therapy. This review provides an up-to-date overview of the current understanding of the pathophysiology, summarizes the evidence of currently available diagnostic tools and treatment options, and highlights the importance of further urgently needed studies aimed at improving diagnosis and investigating novel therapeutic targets for septic cardiomyopathy.

Neuroprotective effects of the inhalational anesthetics isoflurane and xenon after cardiac arrest in pigs.

OBJECTIVE: Neurologic outcome after cardiopulmonary resuscitation from cardiac arrest carries a poor prognosis and treatment options to ameliorate brain damage are limited. DESIGN: Report of two protocols investigating the effects of xenon (Xe) and isoflurane (Iso) in a porcine model of prolonged cardiac arrest and subsequent cardiopulmonary resuscitation on functional neurologic outcomes. SETTING: Prospective, randomized, laboratory animal study. SUBJECTS: Male domestic pigs (Sus scrofa). INTERVENTIONS: After successful resuscitation from 8 mins of cardiac arrest and 5 mins of cardiopulmonary resuscitation, pigs were randomized to receive either Xe for 1 or 5 hrs in comparison with untreated controls 1 hr after cardiopulmonary resuscitation (protocol 1) or to receive Iso or Xe in comparison with untreated controls 10 mins after cardiopulmonary resuscitation (protocol 2). MEASUREMENTS AND MAIN RESULTS: Animals were exposed to an established cognitive function test and gross neurologic performance was assessed using a neurologic deficit score. In protocol 1, Xe administration resulted in improved early cognitive and overall neurologic function, whereas in protocol 2 there was no significant effect on functional performance. CONCLUSIONS: Although Xe conferred functional neurologic improvement even when treatment was delayed for 1 hr, the early treatment with either Xe or Iso translated to only marginal functional improvement.

The acute respiratory distress syndrome: pathophysiology, current clinical practice, and emerging therapies.

INTRODUCTION: More than fifty years after the first description of acute respiratory distress syndrome (ARDS) by Ashbaugh and colleagues, no specific treatment of the underlying pathophysiological processes is available. The current therapeutic regime is comprised of supportive measures such as lung protective ventilation, restrictive fluid management, paralyzing drugs, and prone positioning. Although vast improvements have been made in ARDS-treatment during the last five decades, mortality among patients with severe ARDS remains at an unacceptable rate of 45%. Areas covered: This article reviews the evolution of the currently used definition, established pathophysiological mechanism, highlights the current best clinical practice to treat ARDS, gives a brief outlook on cutting edge trends in ARDS research and closes with an expert opinion on the subject. Expert commentary: Individualizing the provided measures to specific genotypes is the key challenge in ARDS research today. The ongoing digital revolution will help to individualize ARDS-treatment and will therefore presumably improve survival and quality of life.