[Prolonged weaning after long-term ventilation due to SARS-CoV-2 infection: a multicenter retrospective analysis]. / Prolongierte Entwöhnung nach Langzeitbeatmung aufgrund einer SARS-CoV-2-Infektion ­ eine multizentrische retrospektive Analyse.

Some of the patients with SARS-CoV-2 infection (COVID-19) received invasive ventilation during inpatient care. Weaning from ventilation was difficult for some patients (so-called prolonged weaning). PATIENTS: Patients (n=751) with prolonged weaning (reason for ventilation "pneumonia" and "acute respiratory failure") from four centers for the period 2011-23 from the "WeanNet" registry were used as a matched group. RESULTS: The median duration of intensive medical care was 39 (25-68) days. In 19% (37/193) of patients, ECMO support was necessary for a median of 27 (18-51) days. In-hospital mortality was 8.3% (2.7% with vs. 9.6% without ECMO) and 6.8% died in the comparison group. At discharge, 84% (vs. 77% in the control group) were completely weaned and 2.6% (vs. 17.6% in the control group) of patients received non-invasive treatment. Invasive ventilation was still necessary in 7.8% (control group 15.7%). In the observation period of 6 months after discharge, 22.4% of patients required inpatient care and a further 14.1% after 12 months. The overall mortality at 12-month follow-up was 20,6% (5.6% with vs. 24.6% without ECMO). DISCUSSION: The mortality rate of ventilated patients with COVID-19 was very low at 8.3% in the four weaning centers studied. The mortality rate of patients with ECMO treatment was only 2.7%. The mortality rate in the control group was 7.3%. The lower mortality of patients with ECMO treatment was also evident at follow-up of up to 12 months.Patients with prolonged weaning who received invasive ventilation due to COVID-19 showed comparable results in terms of successful weaning and mortality compared to a control group from the WeanNet registry. The long-term results with a survival of more than 80% for the first year after discharge were encouraging.

Randomized Clinical Study of Temporary Transvenous Phrenic Nerve Stimulation in Difficult-to-Wean Patients.

Rationale: Diaphragm dysfunction is frequently observed in critically ill patients with difficult weaning from mechanical ventilation. Objectives: To evaluate the effects of temporary transvenous diaphragm neurostimulation on weaning outcome and maximal inspiratory pressure. Methods: Multicenter, open-label, randomized, controlled study. Patients aged ⩾18 years on invasive mechanical ventilation for ⩾4 days and having failed at least two weaning attempts received temporary transvenous diaphragm neurostimulation using a multielectrode stimulating central venous catheter (bilateral phrenic stimulation) and standard of care (treatment) (n = 57) or standard of care (control) (n = 55). In seven patients, the catheter could not be inserted, and in seven others, pacing therapy could not be delivered; consequently, data were available for 43 patients. The primary outcome was the proportion of patients successfully weaned. Other endpoints were mechanical ventilation duration, 30-day survival, maximal inspiratory pressure, diaphragm-thickening fraction, adverse events, and stimulation-related pain. Measurements and Main Results: The incidences of successful weaning were 82% (treatment) and 74% (control) (absolute difference [95% confidence interval (CI)], 7% [-10 to 25]), P = 0.59. Mechanical ventilation duration (mean ± SD) was 12.7 ± 9.9 days and 14.1 ± 10.8 days, respectively, P = 0.50; maximal inspiratory pressure increased by 16.6 cm H2O and 4.8 cm H2O, respectively (difference [95% CI], 11.8 [5 to 19]), P = 0.001; and right hemidiaphragm thickening fraction during unassisted spontaneous breathing was +17% and -14%, respectively, P = 0.006, without correlation with changes in maximal inspiratory pressure. Serious adverse event frequency was similar in both groups. Median stimulation-related pain in the treatment group was 0 (no pain). Conclusions: Temporary transvenous diaphragm neurostimulation did not increase the proportion of successful weaning from mechanical ventilation. It was associated with a significant increase in maximal inspiratory pressure, suggesting reversal of the course of diaphragm dysfunction. Clinical trial registered with www.clinicaltrials.gov (NCT03096639) and the European Database on Medical Devices (CIV-17-06-020004).

Primary mitochondrial disease as a rare cause of unclear breathlessness and distinctive performance degradation - a case report.

BACKGROUND: Primary muscular disorders (metabolic myopathies, including mitochondrial disorders) are a rare cause of dyspnea. We report a case of dyspnea caused by a mitochondrial disorder with a pattern of clinical findings that can be classified in the known pathologies of mitochondrial deletion syndrome. CASE PRESENTATION: The patient presented to us at 29 years of age, having had tachycardia, dyspnea, and functional impairment since childhood. She had been diagnosed with bronchial asthma and mild left ventricular hypertrophy and treated accordingly, but her symptoms had worsened. After more than 20 years of progressive physical and social limitations was a mitochondrial disease suspected in the exercise testing. We performed cardiopulmonary exercise testing (CPET) with right heart catheterization showed typical signs of mitochondrial myopathy. Genetic testing confirmed the presence of a ~ 13 kb deletion in mitochondrial DNA from the muscle. The patient was treated with dietary supplements for 1 year. In the course of time, the patient gave birth to a healthy child, which is developing normally. CONCLUSION: CPET and lung function data over 5 years demonstrated stable disease. We conclude that CPET and lung function analysis should be used consistently to evaluate the cause of dyspnea and for long-term observation.

[Fatal course of pulmonary embolism after successful pulmonary endarterectomy: a rare case]. / Fataler Verlauf nach erfolgreicher pulmonaler Endarteriektomie ­ der seltene Fall.

We report a case of a 43-year-old woman who suffered from recurrent pulmonary embolism leading to chronic thromboembolic pulmonary hypertension. Pulmonary endarterectomy was performed with good result. However, two years later, after a SARS-CoV2 infection and despite oral anticoagulation therapy, the patient presented with clinical symptoms of pulmonary embolism, which was confirmed by computed tomography as an extensive pulmonary embolism. Despite fibrinolysis therapy and the attempt of interventional thrombus aspiration, the patient died due to non-manageable embolism load.

Value of Cardiopulmonary Exercise Testing in the Prognosis Assessment of Chronic Obstructive Pulmonary Disease Patients: A Retrospective, Multicentre Cohort Study.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is one of the most common chronic diseases associated with high mortality. Previous studies suggested a prognostic role for peak oxygen uptake (VO2peak) assessed during cardiopulmonary exercise testing (CPET) in patients with COPD. However, most of these studies had small sample sizes or short follow-up periods, and despite their relevance, CPET parameters are not included in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) tool for assessment of severity. OBJECTIVES: We therefore aimed to assess the prognostic value of CPET parameters in a large cohort of outpatients with COPD. METHODS: In this retrospective, multicentre cohort study, medical records of patients with COPD who underwent CPET during 2004-2017 were reviewed and demographics, smoking habits, GOLD grade and category, exacerbation frequency, dyspnoea score, lung function measurements, and CPET parameters were documented. Relationships with survival were evaluated using Kaplan-Meier analysis, Cox regression, and receiver operating characteristic (ROC) curves. RESULTS: Of a total of 347 patients, 312 patients were included. Five-year and 10-year survival probability was 75% and 57%, respectively. VO2peak significantly predicted survival (hazard ratio: 0.886 [95% confidence interval: 0.830; 0.946]). The optimal VO2peak threshold for discrimination of 5-year survival was 14.6 mL/kg/min (area under ROC curve: 0.713). Five-year survival in patients with VO2peak <14.6 mL/kg/min versus ≥ 14.6 mL/kg/min was 60% versus 86% in GOLD categories A/B and 64% versus 90% in GOLD categories C/D. CONCLUSIONS: We confirm that VO2peak is a highly significant predictor of survival in COPD patients and recommend the incorporation of VO2peak into the assessment of COPD severity.

Workshop with medical students on physicians' earning opportunities, workload and job satisfaction increases the attractiveness of working self-employed and working in general practice.

BACKGROUND: Among the various factors identified as relevant for primary care career choice, financial considerations have been consistently shown to have an impact. In Germany, reliable and easily understandable information on physicians' earning opportunities in self-employed settings is difficult to obtain for medical students, leading to substantial misperceptions that may negatively affect respective career considerations. This study investigated medical students' evaluation of a 45-min evidence-based workshop on earning opportunities, workload and job satisfaction in different specialties and settings to examine its effect on the perceived attractiveness of working self-employed and working in general practice. METHODS: The workshop was implemented as part of a mandatory general practice clerkship in the fourth study year (of six). Post-hoc evaluations of all participants between October 2017 and September 2018 (one cohort) were analysed cross-sectionally including descriptive statistics, subgroup comparisons and qualitative analysis of free-text answers regarding students' main insights. RESULTS: Response rate was 98.1% (307/313). Participants were on average 25.0 years old, and 68.3% were women. Based on a ten-point scale ranging from 1 = 'no influence' to 10 = 'very big influence', 91.9% confirmed at least some (> = 2) and 57.3% a rather high (> = 5) influence of earning expectations on their career choice process. Regarding the workshop, 86.1% were overall satisfied, and 89.5% indicated they had gained new insights, primarily regarding earning opportunities in different specialties and work settings, and frequently regarding job satisfaction, workload and the structure of revenues and expenditures in a doctor's office (according to qualitative analysis). In the opinion of 89.8% of students, the provided learning content should be part of the undergraduate curriculum. More than half of participants reported an increase regarding the attractiveness of working self-employed and working as a general practitioner, most frequently regarding earning opportunities, but also in general and in respect to job satisfaction, cost-benefit ratio and workload. This increase was significantly higher among students favouring or at least considering a general practice career. CONCLUSIONS: The workshop and its content were appreciated by the students and showed clear potential to usefully complement undergraduate curricula aiming at increasing or reinforcing students' interest in working self-employed and working in general practice.

[Invasive Cardiopulmonary Exercise Testing: A Review]. / Übersicht über die Entwicklung der invasiven Spiroergometrie (iCPET).

Right heart catheterization (RHC) is the internationally standardized reference method for measuring pulmonary hemodynamics under resting conditions. In recent years, increasing efforts have been made to establish the reliable assessment of exercise hemodynamics as well, in order to obtain additional diagnostic and prognostic data. Furthermore, cardiopulmonary exercise testing (CPET), as the most comprehensive non-invasive exercise test, is increasingly performed in combination with RHC providing detailed pathophysiological insights into the exercise response, so-called invasive cardiopulmonary exercise testing (iCPET).In this review, the accumulated experience with iCPET is presented and methodological details are discussed. This complex examination is especially helpful in differentiating the underlying causes of unexplained dyspnea. In particular, early forms of cardiac or pulmonary vascular dysfunction can be detected by integrated analysis of hemodynamic as well as ventilatory and gas exchange data. It is expected that with increasing validation of iCPET parameters, a more reliable differentiation of normal from pathological stress reactions will be possible.

Medical students' perspectives on earning opportunities of self-employed physicians - realistic and relevant for the process of career choice?

BACKGROUND: Several studies report a substantial impact of financial considerations on the process of specialty choice and the willingness to establish one's own practice. In Germany, reliable information on self-employed physicians' earning opportunities is basically available, but not easily accessible and understandable for medical students. Misperceptions might contribute to recruitment problems in some fields, particularly in general practice. In order to identify a possible need for action, we investigated current German medical students' level of information regarding future earnings, and whether net earnings of general practitioners and other physicians working self-employed are estimated realistically. Additionally, we explored students' self-assessments regarding the extent of the impact of expected earnings on their personal career choice process. METHODS: We conducted a cross-sectional questionnaire survey among fourth year (of six) medical students at one medical school (Leipzig). The participants estimated the net earnings of different physicians working self-employed. These estimations were compared with actual earnings data derived from a large German practice panel. RESULTS: Response rate was 73.6% (231/314). The participants' mean age was 24.9 years and 59.1% were women. On a 10-point scale ranging from 1 = 'no influence' to 10='very big influence', 92.6% of the participants described at least some (≥2) influence of earning expectations on their career choice process, and 66.2% stated this influence to be 5 or higher. Every fourth student (26.4%) would rather or definitely reject a certain specialty because of expected low earning opportunities. While 60.4% had already thought about future earnings, only 26.8% had obtained concrete information. Compared with the data derived from the practice panel, the participants substantially underestimated the earning opportunities in self-employed settings, including general practice (median: 4500 vs. 6417€). However, depending on the single estimations, between 87.7 and 95.6% of the students stated they were 'rather uncertain' or 'very uncertain' regarding their estimations. CONCLUSIONS: Despite confirming a relevant impact of financial considerations on career choice, German fourth year medical students are not well informed about earning opportunities in self-employed settings. Providing easily understandable information could enhance transparency and might help students to consider financial issues of career choice on a realistic basis.

Right Heart Catheterization During Exercise in Patients with COPD-An Overview of Clinical Results and Methodological Aspects.

While right heart catheterization (RHC) at rest is the gold standard to assess pulmonary hemodynamics in patients with chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH), the invasive measurement of exercise hemodynamics is less well established in this group. Since exercise hemodynamics are increasingly recognized as important clinical information in patients with PH, our goal was to review the literature in this field to provide a basis for clinical use, further studies, and future recommendations. We identified 69 studies (published since 1968) reporting RHC data in 2819 patients with COPD, of whom 2561 underwent exercise testing. Few studies simultaneously measured gas exchange during exercise. Overall, these studies showed large variations in the patient populations and research questions studied and the methods and definitions employed. Despite these limitations, the data consistently demonstrated the presence of precapillary PH at rest in up to 38% of patients with COPD. With exercise, a relevant proportion of patients developed an abnormal hemodynamic response, depending on the definition used. Furthermore, some studies assessed right ventricular function during exercise and showed a blunted increase in right ventricular ejection fraction. Drug effects and the impact of interventional procedures were also studied. Again, due to large variations in the patients studied and the methods used, firm conclusions are difficult to derive. Despite the limitations of this dataset, several recommendations with respect to technical aspects (body position, exercise protocol, and data acquisition) can be inferred for this challenging patient population and may be helpful for further studies or recommendations.

Cardiopulmonary exercise testing and the 2022 definition of pulmonary hypertension.

Parameters of cardiopulmonary exercise testing significantly discriminate between healthy subjects and patients with pulmonary hypertension (PH), also according to the new 2022 definition of pulmonary hypertension (mean pulmonary arterial pressure mPAP > 20 mmHg). The cut-offs indicating on PH were peakVO2 ≤ 16.7 mL/min/kg (Youden-Index YI = 0.79), petCO2@AT ≤ 34 mmHg (YI = 0.67), and VE/VCO2@AT ≤ 30 (YI = 0.76).

Alpha2 Agonist Use in Critically Ill Adults: A Focus on Sedation and Withdrawal Prevention.

The management of sedation in critically ill adults poses a unique challenge to clinicians. Dexmedetomidine, an α2 agonist, has a unique mechanism and favorable pharmacokinetics, making it an attractive intravenous option for sedation and delirium in the intensive care unit. However, patients may be at risk for withdrawal with prolonged use, adding to the complexity of sedation and agitation management in this patient population. Enteral α2 agents have the benefit of cost savings and ease of administration, thus playing a role in the ability to decrease intravenous sedative use and prevent dexmedetomidine withdrawal. Clonidine and guanfacine are the two most common enteral α2 agents utilized for this purpose, however, there is a paucity of evidence regarding the comparative benefit between the two agents. The decision to use one vs the other agent should be determined based on their differing pharmacology, pharmacokinetics, and side effect profile. The most effective dosing strategy for these agents is also unknown. Ultimately, more robust literature is required to determine enteral α2 agonists place in therapy. This narrative review evaluates the currently available literature on the use of α2 agonists in critically ill adults with an emphasis on sedation, delirium, and withdrawal.

Metabolic cost of unloading pedalling in different groups of patients with pulmonary hypertension and volunteers.

Recently, the parameter internal work (IW) has been introduced as change in oxygen uptake (VO2) between resting and unloading workload in cardiopulmonary exercise testing (CPET). The proportional IW (PIW) was defined as IW divided by VO2 at peak exercise. A second option is to calculate the PIW based on the workload [PIW (Watt)] by considering the aerobic efficiency. The aim of our study was to investigate whether IW and PIW differ between patients with and without pulmonary hypertension and healthy controls. Our study population consisted of 580 patients and 354 healthy controls derived from the Study of Health in Pomerania. The PIW was slightly lower in patients (14.2%) than in healthy controls (14.9%; p = 0.030), but the PIW (Watt) was higher in patients (18.0%) than in the healthy controls (15.9%; p = 0.001). Such a difference was also observed, when considering only the submaximal workload up to the VAT (19.8% in patients and 15.1% in healthy controls; p < 0.001). Since the PIW (Watt) values were higher in patients with pulmonary hypertension, this marker may serve as a useful CPET parameter in clinical practice. In contrast to most of the currently used CPET parameters, the PIW does not require a maximal workload for the patient. Further studies are needed to validate the prognostic significance of the PIW.

Acute COPD exacerbation treatment with noninvasive ventilation.

The establishment of a guideline for long-term noninvasive ventilation treatment (LTH-NIV) of acute hypercapnic exacerbations of chronic obstructive pulmonary disease (AECOPD) requiring acute ventilation has proven elusive. Most studies thus far have shown no mortality benefit of long-term noninvasive ventilation treatment. Using retrospective analysis of the data of our patients (n = 143) recruited from 2012 to 2019, we aimed to compare patients discharged with and without long-term noninvasive ventilation. The follow-up results showed no significant difference (p = 0.233) between the groups [LTH-NIV (n = 83); non-NIV (n = 60)] regarding readmission due to clinical worsening. However, the first- and second-year survival rates were 82% and 72%, respectively, in the LTH-NIV group and significantly different (p = 0.023) from 67 and 55% in the non-NIV group. The statistical models showed a significant mortality risk for the non-NIV group, with a hazard ratio (HR) of 2.82 (1.31; 6.03). To the best of our knowledge, this is the first study to demonstrate the mortality benefit of long-term NIV therapy for patients with AECOPD under real-world conditions.

Correlation of Hemodynamic and Respiratory Parameters in Invasive Cardiopulmonary Exercise Testing (iCPET).

Background: Invasive cardiopulmonary exercise testing (iCPET) is an integral part in the advanced diagnostic workup of pulmonary hypertension (PH). Our study evaluated the relation between hemodynamic and respiratory parameters at two different resting conditions and two defined low exercise levels with a close synchronization of measurements in a broad variety of dyspnea patients. Subjects and methods: We included 146 patients (median age 69 years, range 22 to 85 years, n = 72 female) with dyspnea of uncertain origin. Invasive hemodynamic and gas exchange parameters were measured at rest, 45° upright position, unloaded cycling, 25 and 50 W exercise. All measurements were performed in a single RHC procedure. Results: Oxygen uptake (VO2/body mass) correlated significantly with cardiac index (all p ≤ 0.002) at every resting and exercise level and with every method of cardiac output measurement (thermodilution, method of Fick). Mean pulmonary arterial pressure (PAPmean) correlated with all respiratory parameters (respiratory rate, partial end-tidal pressures of oxygen and carbon dioxide [petCO2 and petO2], ventilation/carbon dioxide resp. oxygen ratio [VE/VCO2, VE/VO2], and minute ventilation [VE], all p < 0.05). These correlations improved with increasing exercise levels from rest via unloaded cycling to 25 W. There was no correlation with right atrial or pulmonary arterial wedge pressure. Summary: In dyspnea patients of different etiologies, the cardiac index is closely linked to VO2 at every level of rest and submaximal exercise. PAPmean is the only pressure that correlates with different respiratory parameters, but this correlation is highly significant and stable at rest, unloaded cycling and at 25 W.

Comparison between thermodilution and Fick methods for resting and exercise-induced cardiac output measurement in patients with chronic dyspnea.

Studies comparing thermodilution (TD) and the direct Fick method (dFM) for cardiac output (CO) measurement are rare. We compared CO measurements between TD (2-5 cold water injections), the dFM, and indirect Fick method (iFM) at rest and during exercise, and assessed the effect of averaging different numbers of TD measurements during exercise. This retrospective study included 300 patients (52.3% women, mean age 66 ± 11 years) having pulmonary hypertension (76.0%) or unexplained dyspnea. Invasive hemodynamic and gas exchange parameters were measured at rest (supine; n = 300) and during unloaded cycling (semi-supine; n = 275) and 25-W exercise (semi-supine; n = 240). All three methods showed significant differences in CO measurement (ΔCO) at rest (p ≤ 0.001; ΔCO > 1 L/min: 45.0% [iFM vs. dFM], 42.0% [iFM vs. TD], and 45.7% [TD vs. dFM]). ΔCO (TD vs. dFM) was significant during unloaded cycling (p < 0.001; ΔCO > 1 L/min: 56.6%) but not during 25-W exercise (p = 0.137; ΔCO > 1 L/min: 52.8%). ΔCO (TD vs. dFM) during 25-W exercise was significant when using one or two (p ≤ 0.01) but not three (p = 0.06) TD measurements. Mean ΔCO (TD [≥3 measurements] vs. dFM) was -0.43 ± 1.98 and -0.06 ± 2.29 L/min during unloaded and 25-W exercise, respectively. Thus, TD and dFM CO measurements are comparable during 25-W exercise (averaging ≥3 TD measurements), but not during unloaded cycling or at rest. Individual ΔCOs vary substantially and require critical interpretation to avoid CO misclassification.

Prognostic Relevance of Cardiopulmonary Exercise Testing for Patients with Chronic Thromboembolic Pulmonary Hypertension.

Background: Following acute pulmonary embolism (PE), a relevant number of patients experience decreased exercise capacity which can be associated with disturbed pulmonary perfusion. Cardiopulmonary exercise testing (CPET) shows several patterns typical for disturbed pulmonary perfusion. Research question: We aimed to examine whether CPET can also provide prognostic information in chronic thromboembolic pulmonary hypertension (CTEPH). Study Design and Methods: We performed a multicenter retrospective chart review in Germany between 2002 and 2020. Patients with CTEPH were included if they had ≥6 months of follow-up and complete CPET and hemodynamic data. Symptom-limited CPET was performed using a cycle ergometer (ramp or Jones protocol). The association of anthropometric data, comorbidities, symptoms, lung function, and echocardiographic, hemodynamic, and CPET parameters with survival was examined. Mortality prediction models were calculated by Cox regression with backward selection. Results: 345 patients (1532 person-years) were included; 138 underwent surgical treatment (pulmonary endarterectomy or balloon pulmonary angioplasty) and 207 received only non-surgical treatment. During follow-up (median 3.5 years), 78 patients died. The death rate per 1000 person-years was 24.9 and 74.2 in the surgical and non-surgical groups, respectively (p < 0.001). In age- and sex-adjusted Cox regression analyses, CPET parameters including peak oxygen uptake (VO2peak, reflecting cardiopulmonary exercise capacity) were prognostic in the non-surgical group but not in the surgical group. In mortality prediction models, age, sex, VO2peak (% predicted), and carbon monoxide transfer coefficient (% predicted) showed significant prognostic relevance in both the overall cohort and the non-surgical group. In the non-surgical group, Kaplan−Meier analysis showed that patients with VO2peak below 53.4% predicted (threshold identified by receiver operating characteristic analysis) had increased mortality (p = 0.007). Interpretation: The additional measurement of cardiopulmonary exercise capacity by CPET allows a more precise prognostic evaluation in patients with CTEPH. CPET might therefore be helpful for risk-adapted treatment of CTEPH.

Predictors of survival after prolonged weaning from mechanical ventilation.

PURPOSE: Weaning from mechanical ventilation is a key component of intensive care treatment; however, this process may be prolonged as some patients require care at specialised centres. Current data indicate that weaning from invasive mechanical ventilation is successful in approximately 65% of patients; however, data on long-term survival after discharge from a weaning centre are limited. MATERIALS AND METHODS: We analysed predictors of survival among 597 patients (392 men, mean age 68 ± 11) post-discharge from a specialised German weaning centre. RESULTS: Complete weaning from mechanical ventilation was achieved in 407 (57.8%) patients, and 106 patients (15.1%) were discharged with non-invasive ventilation; thus, prolonged weaning was successful in 72.9% of the patients. The one-year and five-year survival rates post-discharge were 66.5% and 37.1%, respectively. Age, duration of mechanical ventilation, certain clusters of comorbidities, and discharged with mechanical ventilation significantly influenced survival (p < .001). Completely weaned patients who were discharged with a tracheostomy had a significantly reduced survival rate than did those who were completely weaned and discharged with a closed tracheostomy (p = .004). CONCLUSIONS: The identified predictors of survival after prolonged weaning could support therapeutic strategies during patients' intensive care unit stay. Patients should be closely monitored after discharge from a weaning centre.

Exercise and fluid challenge during right heart catheterisation for evaluation of dyspnoea.

This prospective study compared exercise test and intravenous fluid challenge in a single right heart catheter procedure to detect latent diastolic heart failure in patients with echocardiographic heart failure with preserved ejection function. We included 49 patients (73% female) with heart failure with preserved ejection function and pulmonary artery wedge pressure ≤15 mmHg. A subgroup of 26 patients had precapillary pulmonary hypertension. Invasive haemodynamic and gas exchange parameters were measured at rest, 45° upright position, during exercise, after complete haemodynamic and respiratory recovery in lying position, and after rapid infusion of 500 mL isotonic solution. Most haemodynamic parameters increased at both exercise and intravenous fluid challenge, with the higher increase at exercise. Pulmonary vascular resistance decreased by -0.21 wood units at exercise and -0.56 wood units at intravenous fluid challenge (p = 0.3); 20% (10 of 49) of patients had an increase in pulmonary artery wedge pressure above the upper limit of 20 mmHg at exercise, and 20% above the respective limit of 18 mmHg after intravenous fluid challenge. However, only three patients exceeded the upper limit of pulmonary artery wedge pressure in both tests, i.e. seven patients only at exercise and seven other patients only after intravenous fluid challenge. In the subgroup of pulmonary hypertension patients, only two patients exceeded pulmonary artery wedge pressure limits in both tests, further five patients at exercise and four patients after intravenous fluid challenge. A sequential protocol in the same patient showed a significantly higher increase in haemodynamic parameters at exercise compared to intravenous fluid challenge. Both methods can unmask diastolic dysfunction at right heart catheter procedure, but in different patient groups.

Flow rate variance of a fully implantable pump for the delivery of intravenous treprostinil in pulmonary arterial hypertension.

Implantable infusion pumps might improve the convenience and safety of intravenous treprostinil for pulmonary arterial hypertension. The LENUS Pro® pump (approved in Europe) has a fixed flow rate. Based on 126 pumps and 2853 refills, we retrospectively analyzed the actual flow rate from 09/2010 to 09/2018. A relevant flow rate variance is evident after three years; therefore, flow rate monitoring and dose adjustment are mandatory.

Intravenous treprostinil via an implantable pump in pediatric pulmonary arterial hypertension.

Intravenous prostacyclin-based therapy improves survival in children with pulmonary arterial hypertension (PAH), but is typically administered via an external infusion pump, which places a considerable burden on the patient. Implanted pumps may overcome some of the limitations of external pumps. We describe the first long-term use of an implanted pump for intravenous treprostinil delivery in a pediatric patient with PAH. Our patient was experiencing marked dyspnea on exertion despite triple combination therapy with bosentan, sildenafil, and inhaled iloprost. Parenteral prostacyclin-based therapy was discussed and the patient rejected options involving external pumps; she finally chose intravenous treprostinil delivery via an implanted pump (LENUS Pro®; fixed flow rate; 20 ml reservoir). The patient underwent pump implantation in July 2012 (aged 14 years) under general anesthesia with no peri- or postoperative complications. She showed marked improvements in fatigue and dyspnea over the subsequent weeks, and her inhaled iloprost regimen was slowly decreased and stopped after six months. During follow-up, the pump showed an unexpected, progressive increase in flow rate that allowed a treprostinil dose of 170 ng/kg/min to be achieved, but at the cost of shortened intervals between refills. The pump was therefore replaced in August 2017 with a newer model with an adjustable flow rate (Siromedes®). A catheter dislocation was corrected under local anesthesia one week after the replacement surgery. The patient is currently receiving treprostinil 170 ng/kg/min with percutaneous refills every 12-13 days. Thus, implantable pumps might be a valuable alternative to external pumps for treprostinil infusion in pediatric PAH.