Transplantation of initially rejected donor lungs using ex vivo lung perfusion: A 5-year experience.

BACKGROUND: Ex vivo lung perfusion (EVLP) is a method for the evaluation and reconditioning of high-risk donor lungs to increase the pool of potential donor lungs. METHODS: We reviewed all consecutive patients who received lung transplants from May 2012 to May 2017 with follow-up until July 2021. EVLP was used in lungs initially rejected due to inadequate oxygenation but without other contraindications. Lungs with improved oxygenation levels above the threshold were transplanted. The primary endpoint was the time to graft failure, which was defined as the time from surgery to death or re-transplantation, whichever occurred first. The secondary outcome was freedom from chronic lung allograft dysfunction. RESULTS: A total of 157 patients underwent transplantation during the study period. Thirty-nine patients received EVLP-treated donor lungs. Restricted mean graft survival time up to 7 years is 5.14 years for non-EVLP and 4.19 for EVLP, the difference being -0.95 (confidence interval [CI]-1.93 to 0.04, p = .059). The hazard ratio is 1.66 (CI 1.00-2.75, p = .046). Chronic lung allograft dysfunction was the highest contributor to mortality in both groups. There were significant differences in freedom from chronic lung allograft dysfunction at 12 and 24 months of follow-up (p = .005 and p = .030, respectively). Subgroup analyses revealed that the first patients who received EVLP in 2012-2013 had a substantially worse 5-year graft survival than those who received EVLP more recently in 2016-2017 (14.3% vs. 60.0%). For the latter, the 5-year graft survival was observed to be remarkably close to the non-EVLP group (60.8%). CONCLUSION: Long-term survival was significantly lower, and lung function was poorer among recipients in the EVLP group than in the non-EVLP group. However, the outcome of patients who received EVLP-treated lungs was observed to improve steadily after the first 2 years after EVLP was introduced in Denmark.

Anesthesiologists' airway management expertise: Identifying subjective and objective knowledge gaps.

BACKGROUND: Failure in airway management continues to cause preventable patient harm, and the recommended continuing education is challenged by anesthesiologists' unknown knowledge gaps. This study aimed to identify anesthesiologists' subjective and objective knowledge gaps as well as areas where anesthesiologists are incorrect and unaware. METHODS: An adaptive E-learning program with 103 questions on adult airway management was used for subjective and objective assessment of anesthesiologists' knowledge. All anesthesiologists in the Capital Region of Denmark were invited to participate. RESULTS: The response rate was 67% (191/285). For preoperative planning, participants stated low confidence (subjective assessment) regarding predictors of difficult airway management in particular (69.1%-79.1%). Test scores (objective assessment) were lowest for obstructive sleep apnea as a predictor of difficult airway management (28.8% correct), with participants being incorrect and unaware in 33.5% of the answers. For optimization of basic techniques, the lowest confidence ratings related to patient positioning and prediction of difficulties (57.4%-83.2%), which agreed with the lowest test scores. Concerning advanced techniques, videolaryngoscopy prompted the lowest confidence (72.4%-85.9%), while emergency cricothyrotomy resulted in the lowest test scores (47.4%-67.8%). Subjective and objective assessments correlated and lower confidence was associated with lower test scores: preoperative planning [r = -.58, P < .001], optimization of basic techniques [r = -.58, P = .002], and advanced techniques [r = -.71, P < .001]. CONCLUSION: We identified knowledge gaps in important areas of adult airway management with differing findings from the subjective and objective assessments. This underlines the importance of objective assessment to guide continuing education.

Comparing Methods for Cardiac Output: Intraoperatively Doppler-Derived Cardiac Output Measured With 3-Dimensional Echocardiography Is Not Interchangeable With Cardiac Output by Pulmonary Catheter Thermodilution.

BACKGROUND: Estimation of cardiac output (CO) is essential in the treatment of circulatory unstable patients. CO measured by pulmonary artery catheter thermodilution is considered the gold standard but carries a small risk of severe complications. Stroke volume and CO can be measured by transesophageal echocardiography (TEE), which is widely used during cardiac surgery. We hypothesized that Doppler-derived CO by 3-dimensional (3D) TEE would agree well with CO measured with pulmonary artery catheter thermodilution as a reference method based on accurate measurements of the cross-sectional area of the left ventricular outflow tract. METHODS: The primary aim was a systematic comparison of CO with Doppler-derived 3D TEE and CO by thermodilution in a broad population of patients undergoing cardiac surgery. A subanalysis was performed comparing cross-sectional area by TEE with cardiac computed tomography (CT) angiography. Sixty-two patients, scheduled for elective heart surgery, were included; 1 was subsequently excluded for logistic reasons. Inclusion criteria were coronary artery bypass surgery (N = 42) and aortic valve replacement (N = 19). Exclusion criteria were chronic atrial fibrillation, left ventricular ejection fraction below 0.40 and intracardiac shunts. Nineteen randomly selected patients had a cardiac CT the day before surgery. All images were stored for blinded post hoc analyses, and Bland-Altman plots were used to assess agreement between measurement methods, defined as the bias (mean difference between methods), limits of agreement (equal to bias ± 2 standard deviations of the bias), and percentage error (limits of agreement divided by the mean of the 2 methods). Precision was determined for the individual methods (equal to 2 standard deviations of the bias between replicate measurements) to determine the acceptable limits of agreement. RESULTS: We found a good precision for Doppler-derived CO measured by 3D TEE, but although the bias for Doppler-derived CO by 3D compared to thermodilution was only 0.3 L/min (confidence interval, 0.04-0.58), there were wide limits of agreement (-1.8 to 2.5 L/min) with a percentage error of 55%. Measurements of cross-sectional area by 3D TEE had low bias of -0.27 cm (confidence interval, -0.45 to -0.08) and a percentage error of 18% compared to cardiac CT angiography. CONCLUSIONS: Despite low bias, the wide limits of agreement of Doppler-derived CO by 3D TEE compared to CO by thermodilution will limit clinical application and can therefore not be considered interchangeable with CO obtained by thermodilution. The lack of agreement is not explained by lack of agreement of the 3D technique.

Airway management in a bronchoscopic simulator based setting: an observational study.

BACKGROUND: Several simulation-based possibilities for training flexible optical intubation have been developed, ranging from non-anatomical phantoms to high-fidelity virtual reality simulators. These teaching devices might also be used to assess the competence of trainees before allowing them to practice on patients. OBJECTIVES: To evaluate the validity of airway simulation as an assessment tool for the acquisition of the preclinical basic skills in flexible optical intubation and to investigate anaesthetists' opinion on airway simulation. DESIGN: Observational study. SETTING: International airway course. PARTICIPANTS: Thirty-six consultants and residents in anaesthesiology. MAIN OUTCOME MEASURES: All participants performed one single procedure on each of the three different simulators. Their video-filmed performances were assessed by two independent, blinded experts and their opinions of simulation were surveyed. RESULTS: The mean score increased 0.33 points after each attempt (P = 0.021). The attitude towards simulation-based training was always more than 4 on a scale from 1 to 5. Only 25% of the procedures were performed to satisfaction with a learning-by-testing effect (P = 0.021). Generalisability coefficient was 0.55, and there was no correlation between the number of clinical procedures performed beforehand and test scores (P = 0.93). CONCLUSION: The increase in mean score is a learning effect indicating that simulator training allows for entry of the learning curve at a higher level. The anaesthetists in our study agreed completely that simulation-based training was useful regardless of the fidelity of the simulator. Local, practical issues such as cost and portability should decide available simulation modalities in each teaching hospital.