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.

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.

[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.

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.

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.

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.

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.

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.

Effects of inhaled nitric oxide on outcome after prolonged cardiac arrest in mild therapeutic hypothermia treated rats.

Guidelines endorse targeted temperature management to reduce neurological sequelae and mortality after cardiac arrest (CA). Additional therapeutic approaches are lacking. Inhaled nitric oxide (iNO) given post systemic ischemia/reperfusion injury improves outcomes. Attenuated inflammation by iNO might be crucial in brain protection. iNO augmented mild therapeutic hypothermia (MTH) may improve outcome after CA exceeding the effect of MTH alone. Following ten minutes of CA and three minutes of cardiopulmonary resuscitation, 20 male Sprague-Dawley rats were randomized to receive MTH at 33 °C for 6hrs or MTH + 20ppm iNO for 5hrs; one group served as normothermic control. During the experiment blood was taken for biochemical evaluation. A neurological deficit score was calculated daily for seven days post CA. On day seven, brains and hearts were harvested for histological evaluation. Treatment groups showed a significant decrease in lactate levels six hours post resuscitation in comparison to controls. TNF-α release was significantly lower in MTH + iNO treated animals only at four hours post ROSC. While only the combination of MTH and iNO improved neurological function in a statistically significant manner in comparison to controls on days 4-7 after CA, there was no significant difference between groups treated with MTH and MTH + iNO.

Influence of argon on temperature modulation and neurological outcome in hypothermia treated rats following cardiac arrest.

AIM OF THE STUDY: Combining xenon and mild therapeutic hypothermia (MTH) after cardiac arrest (CA) confers a degree of protection that is greater than either of the two interventions alone. However, xenon is very costly which might preclude a widespread use. We investigated whether the inexpensive gas argon would enhance hypothermia induced neurologic recovery in a similar manner. METHODS: Following nine minutes of CA and three minutes of cardiopulmonary resuscitation 21 male Sprague-Dawley rats were randomized to receive MTH (33°C for 6h), MTH plus argon (70% for 1h), or no treatment. A first day condition score assessed behaviour, motor activity and overall condition. A neurological deficit score (NDS) was calculated daily for seven days following the experiment before the animals were killed and the brains harvested for histopathological analysis. RESULTS: All animals survived. Animals that received MTH alone showed best overall neurologic function. Strikingly, this effect was abolished in the argon-augmented MTH group, where animals showed worse neurologic outcome being significant in the first day condition score and on day one to three and five in the NDS in comparison to MTH treated rats. Results were reflected by the neurohistopathological analysis. CONCLUSION: Our study demonstrates that argon augmented MTH does not improve functional recovery after CA in rats, but may even worsen neurologic function in this model.

Calcification of Vascular Smooth Muscle Cells and Imaging of Aortic Calcification and Inflammation.

Cardiovascular disease is the leading cause of morbidity and mortality in the world. Atherosclerotic plaques, consisting of lipid-laden macrophages and calcification, develop in the coronary arteries, aortic valve, aorta, and peripheral conduit arteries and are the hallmark of cardiovascular disease. In humans, imaging with computed tomography allows for the quantification of vascular calcification; the presence of vascular calcification is a strong predictor of future cardiovascular events. Development of novel therapies in cardiovascular disease relies critically on improving our understanding of the underlying molecular mechanisms of atherosclerosis. Advancing our knowledge of atherosclerotic mechanisms relies on murine and cell-based models. Here, a method for imaging aortic calcification and macrophage infiltration using two spectrally distinct near-infrared fluorescent imaging probes is detailed. Near-infrared fluorescent imaging allows for the ex vivo quantification of calcification and macrophage accumulation in the entire aorta and can be used to further our understanding of the mechanistic relationship between inflammation and calcification in atherosclerosis. Additionally, a method for isolating and culturing animal aortic vascular smooth muscle cells and a protocol for inducing calcification in cultured smooth muscle cells from either murine aortas or from human coronary arteries is described. This in vitro method of modeling vascular calcification can be used to identify and characterize the signaling pathways likely important for the development of vascular disease, in the hopes of discovering novel targets for therapy.

Combining Near Infrared Fluorescent Imaging for Calcification and Inflammation in Vascular Tissue Samples Ex Vivo.

Quantification of vascular lesions in models of vascular calcification is crucial for testing novel treatments, but remains a challenging endeavor. Conventional methods include Oil-Red-O staining of whole tissue samples, calcium quantification in incinerated samples, or stereoisometric histologic processing. While most techniques offer fairly high levels of reliability, all of them share the fact that samples are not available for other assays following the analysis, as tissue is altered or destroyed in the course of the procedure. Furthermore, none is capable of measuring both calcification and inflammation at the same time. Here we present a novel technique for the simultaneous quantification of vascular inflammation and calcification, after which samples are still available for further histologic processing.

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.