Background To further improve treatment quality and patient orientation, a multiprofessional enhanced recovery after surgery (ERAS (R)) transformation program was initiated in our clinic in January 2020. The ERAS (R) treatment pathway for colorectal surgery was established in October 2020. Objective The aim of the study was to show that the perioperative treatment quality can be increased by implementing a certified ERAS (R) program in the setting of a fast-track pathway that has been established since 2008. Material and methods The first ERAS (R) patients from October/November 2020 (ERAS (R)) were compared with those of a representative consecutive control cohort (pre-ERAS (R)) who had undergone interventions from August to December 2019. Patient care and data collection of the ERAS (R) patients were ensured by an ERAS (R) nurse in daily visits. For the comparison cohorts, the electronic patient files were analyzed and historical colon pathway data from our clinic from 2008 were used. Results and conclusion A total of 10 ERAS (R) and 50 pre-ERAS (R) patients were included. After the ERAS (R) transformation, an increase in overall compliance with ERAS (R) guideline recommendations from 45% (pre-ERAS (R)) to 75% (ERAS (R)) was achieved. The number of days to tolerance of solid food decreased from 2 days (pre-ERAS (R)) to 1 day (ERAS (R)). The general postoperative complication rate was comparable (22% pre-ERAS (R) vs. 20% ERAS (R)). Most noticeable was the reduction of the median hospital stay of 9 days in the historical cohort to 3 days after ERAS (R) implementation. We attribute the necessary high ERAS (R) pathway compliance of 75% to a successful combination of process standards and multiprofessional ERAS (R) teams.

Ventilation heterogeneity is frequent in bronchial asthma and can be assessed using multiple breath wash-out testing (MBW). Most data is available in paediatric patients and using nitrogen as a tracer gas. We aimed to evaluate sulphur hexafluoride (SF6) MBW in adult asthmatics. Spirometry, whole-body plethysmography, impulse oscillometry and SF6-MBW were prospectively performed. MBW parameters reflecting global (lung clearance index, LCI), acinar (S-acin) and conductive (S-cond) ventilation heterogeneity were derived from three consecutive wash-outs. LCI was calculated for the traditional 2.5% and an earlier 5% stopping point that has the potential to reduce wash-out times. 91 asthmatics (66%) and 47 non-asthmatic controls (34%) were included in final analysis. LCI2.5 and LCI5 were higher in asthmatics (p<0.001). Likewise, S-acin and S-cond were elevated (p<0.001 and p<0.01). Coefficient of variation was 3.4% for LCI2.5 and 3.5% for LCI5 in asthmatics. Forty-one asthmatic patients had normal spirometry. ROC analysis revealed an AUC of 0.906 for the differentiation from non-asthmatic controls exceeding diagnostic performance of individual and conventional parameters (AUC=0.819, p<0.05). SF6-MBW is feasible and reproducible in adult asthmatics. Ventilation heterogeneity is increased as compared to non-asthmatic controls persisting in asthmatic patients with normal spirometry. Diagnostic performance is not affected using an earlier LCI stopping point while reducing wash-out duration considerably.

Background: Functional diagnosis of COPD is primarily based on central obstruction in spirometry. Impulse oscillometry (IOS) and multiple breath washout (MBW) can additionally detect peripheral obstruction or ventilation heterogeneity (VH). We aimed to evaluate IOS and MBW for a refined phenotyping and therapeutic implications. Methods: We performed body plethysmography, IOS and MBW (SF6) in 66 COPD patients (74% men, 70% GOLD I/II) in a prospective, cross-sectional protocol. In an 8-week cross-over design, the effect of dual bronchodilator therapy (tiotropium/olodaterol, TO) was compared to monotherapy (formoterol, F) in 12 patients. Results: IOS showed an abnormal frequency dependence of resistance (D5-20, 55±45%) and reactance area (Ax, 1.65±1.60). Global VH (lung clearance index, LCI) was elevated to 10.3±2.0. An increase of 0.34±0.21 L-1 in acinar phase-III slopes (Sacin) resembles local VH. Clusters corresponding to components of conventional lung function testing, peripheral resistance and VH were identified (Figure). SGRQ improvement following TO was predicted by changes in small airways during F (D5-20, Sacin) affected early in COPD pathogenesis. Signs of central obstruction and emphysema (TLCO, FEV1, LCI) assessed prior to therapy added predictive value. Conclusion: IOS and MBW add information to current diagnostic concepts in COPD. Initial phenotyping is improved and consequences for differential therapy can be derived.

Background: Ventilation heterogeneity is frequent in obstructive lung disease and can be assessed using multiple breath washout testing (MBW). In bronchial asthma, most data is available in pediatric collectives and using N2 as tracer gas suffering from several technical issues. We therefore aimed to evaluate the feasibility of MBW using sulfur hexafluoride (SF6) in adult asthmatic patients. Methods: MBW parameters reflecting global (lung clearance index, LCI), acinar (Sacin) and conductive (Scond) ventilation heterogeneity were derived from SF6-MBW. Results: 91 asthmatic patients (66%) and 47 controls (34%) were included. LCI was significantly higher in asthmatic patients than in healthy controls (p<0.001). Likewise, Sacin and Scond were significantly elevated (p<0.001 and p<0.01). Coefficient of variation was 3.4±2.4% for LCI in patients with asthma and 3.0±1.9% (p=0.28) in controls. Sacin and Scond showed larger variation. Forty-one asthma patients had normal spirometry. ROC analysis revealed an AUC of 0.886 for the differentiation from healthy controls using a regularized generalized linear model including MBW parameters. This exceeded diagnostic performance of the individual parameters and a model based on parameters of conventional lung function testing only (AUC=0.819, p<0.05). Conclusion: SF6-MBW is feasible and reproducible in adults with bronchial asthma. Global and local ventilation heterogeneity is increased as compared to pulmonary healthy controls. Differences persist in asthmatic patients with normal spirometry. MBW parameters therefore may contain additional information that can be used to identify asthmatic patients missed by current tests.

Airways obstruction is frequent in patients with pulmonary hypertension (PH). Small airway disease (SAD) was identified as a major contributor to resistance and symptoms. However, it is easily missed using current diagnostic approaches. We aimed to evaluate more elaborate diagnostic tests such as impulse oscillometry (IOS) and SF6-multiple-breath-washout (MBW) for the assessment of SAD in PH. Twenty-five PH patients undergoing body-plethysmography, IOS and MBW testing were prospectively included and equally matched to pulmonary healthy and non-healthy controls. Lung clearance index (LCI) and acinar ventilation heterogeneity (Sacin) differed significantly between PH, healthy and non-healthy controls. Likewise, differences were found for all IOS parameters between PH and healthy, but not non-healthy controls. Transfer factor corrected for ventilated alveolar volume (TLCO/VA), frequency dependency of resistance (D5-20), resonance frequency (Fres) and Sacin allowed complete differentiation between PH and healthy controls (AUC (area under the curve) = 1.0). Likewise, PH patients were separated from non-healthy controls (AUC 0.762) by D5-20, LCI and conductive ventilation heterogeneity (Scond). Maximal expiratory flow (MEF) values were not associated with additional diagnostic values. MBW and IOS are feasible in PH patients both providing additional information. This can be used to discriminate PH from healthy and non-healthy controls. Therefore, further research targeting SAD in PH and evaluation of therapeutic implications is justified.

Multiple breath washout (MBW) became a valuable research tool assessing ventilation heterogeneity. However, routine clinical application still faces several challenges. Deriving MBW parameters from three technically acceptable measurements according to current recommendations prolongs test times. We therefore aimed to evaluate reporting only duplicate measurements in healthy adults and pulmonary disease.

Background: Multiple breath washout (MBW) showed promising results in the assessment of ventilation heterogeneity in pulmonary disease. However, the test is rather time consuming and according to current ERS/ATS recommendations three technically acceptable measurements should be reported. Available data for optimizing test methodology is mostly restricted to nitrogen based devices and infant lung disease. We therefore aimed to evaluate the number of required measurements in adults using sulfur hexafluoride MBW. Methods: LCI was derived from three consecutive MBW tests in pulmonary healthy controls (n=19) as well as patients suffering from COPD (n=33), bronchial asthma (n=32) and sarcoidosis (n=19). All patients were in clinically stable condition. Results: LCI significantly differed between controls (7.4±0.8), sarcoidosis (8.1±1.2), bronchial asthma (9.2±1.9) and COPD (10.8±2.2, p<0.001, ANOVA). Repeatability was high in all groups with coefficients of variation between 2.5% in controls and 3.6% in COPD. When only including the first two measurements, LCI remained stable in all groups with mean changes of -0.1±1.2% in controls, +0.2±1.7% in COPD, +0.3±1.3% in sarcoidosis and +0.4±1.4% in asthma, respectively (p=0.6, ANOVA). Mean overall test time reductions ranged from 155s in controls (33%) to 200s in COPD (34%) being comparable throughout all groups. Conclusion: Reporting two valid LCI measurements seems to be sufficient in healthy controls as well as pulmonary disease. Absolute values are not altered while overall test time can be considerably reduced.