Water-film thickness imaging based on time-multiplexed near-infrared absorption with up to 500 Hz repetition rate.

We demonstrate high-repetition-rate imaging of the liquid-film thickness in the 50-1000 µm range resulting from impinging water droplets on a glass surface. The pixel-by-pixel ratio of line-of-sight absorption at two time-multiplexed near-infrared wavelengths at 1440 and 1353 nm was detected with a high-frame-rate InGaAs focal-plane array camera. Frame rates of 1 kHz and thus measurement rates of 500 Hz could be achieved, well suited to capture the fast dynamics of droplet impingement and film formation. The droplets were sprayed onto the glass surface using an atomizer. Suitable absorption wavelength bands for water droplet/film imaging were determined from Fourier-transform infrared (FTIR) spectra of pure water between 298 and 338 K. At 1440 nm, the water absorption is nearly temperature-independent, making the measurements robust against temperature fluctuations. Time-resolved imaging measurements capturing the dynamics of the water droplet impingement and evolution were successfully demonstrated.

Simultaneous measurement of liquid-film thickness and solute concentration of aqueous solutions of two urea derivatives using NIR absorption.

We present a method to simultaneously measure the film thickness and individual concentrations of two urea derivates (urea CH4N2O and dimethylurea C3H8N2O) mixed in an aqueous solution at constant temperature using near-infrared (NIR) absorption at multiple specific wavelengths. Fourier transform infrared (FTIR) spectra of aqueous mixtures of urea and dimethylurea solutions were recorded in the 1250-2500 nm wavelength range in thin-layer quartz cuvettes at room temperature. The spectra reveal suitable detection wavelengths, i.e., 1450, 1933, 2200, and 2270 nm, for which both the absorption coefficient and its variation with the species concentration are large enough to achieve satisfactory detection sensitivity and selectivity. For validation measurements, samples were prepared in thin-layer quartz transmission cells with known path lengths and mixture compositions in the range 100-1000 µm and 0-40 wt.%, respectively. Film thickness and mass fractions of both species were determined from measured absorbance ratios in the determined characteristic wavelength bands.

[The Diagnosis is Obvious]. / Die Diagnose liegt auf der Hand.

Clinically amyopathic dermatomyositis (CADM) is a rare entity of dermatomyositis. As a rule, CADM presents without muscular involvement. Thus, the level of creatine kinase is most commonly within the normal range. Dermal manifestations of CADM are Gottron's papules and mechanic's hands. In the case of melanoma differentiation-associated gene 5 intracellular pathogen sensor (MDa5 antibodies), CADM is often associated with a rapidly progressive and severe form of interstitial lung disease. Pulmonary function tests reveal restriction and hypoxemia of varying degree. Features of ground-glass opacities, reticulations and consolidations are detected in high-resolution CT scan. Lymphocytes are sometimes predominant in bronchioloalveolar lavage. Pathologists see a picture similar to non-specific interstitial lung disease or organizing pneumonia. Pronounced immunosuppression is the most common therapy. However, sometimes a combination of different immunosuppressive therapies is necessary. A novel strategy to treat CADM with rapidly progressive interstitial lung disease is the Janus kinase inhibitor tofacitinib. Treatment can be monitored with the level of ferritin and MDa5-antibody titer. Mortality is as high as 84 %.

NIR sensor for aqueous urea solution film thickness and concentration measurement using a broadband light source.

We demonstrate a multi-wavelength near-infrared (NIR) broadband absorption sensor for the simultaneous monitoring of layer thickness and urea concentration of aqueous urea solutions. Samples were prepared in thin-layer quartz transmission cells. Film thickness and urea mass fraction (at constant temperature) were determined from measured transmittance ratios in characteristic wavelength bands selected by narrowband filters in front of the detector and converted to absorbance ratios. Suitable emission bands were selected depending on the sensitivity of the NIR absorption spectrum of the solution with respect to temperature and solute concentration. For this purpose, Fourier transform IR spectra of aqueous urea solutions were recorded in the 1250-2500 nm wavelength range for urea concentrations between 0 and 40 wt.% and temperatures between 298 K and 338 K. A prototype sensor was designed using a continuous-wave fiber-coupled incoherent tungsten lamp, subsequent intensity modulation, and lock-in detection of the transmitted radiation. The sensor concept was validated with measurements using a calibration cell providing liquid layers of variable thicknesses (7-1000 µm).

The impact of venovenous extracorporeal membrane oxygenation on cytokine levels in patients with severe acute respiratory distress syndrome: a prospective, observational study.

OBJECTIVE: The immunoinflammatory response is central to the pathogenesis of acute respiratory distress syndrome (ARDS). However, little is known how this is affected by venovenous (VV) extracorporeal membrane oxygenation (ECMO). Our objective was to investigate the factors that influence the inflammatory response of patients with ARDS undergoing VV ECMO, and to analyse the impact of this response on hospital mortality. DESIGN AND SETTING: A prospective observational study of all consecutive patients with severe ARDS who had VV ECMO at a tertiary German ECMO centre from 2009 to 2015. Patients without complete datasets were excluded. Cytokines (interleukin [IL]6, IL8 and tissue necrosis factor [TNF]α) and inflammatory markers (white cell count and C-reactive protein) were assessed before ECMO initiation and on Days 1, 5 and 10, before explantation and at explantation. RESULTS: A total of 262 adult patients undergoing VV ECMO were analysed. Their median Sequential Organ Failure Assessment score was 12, PaO2/FiO2 ratio was 64 mmHg, and overall in-hospital mortality was 34%. Cytokine levels fell quickly within 24 hours and fell further over the first 5 days. Extra-pulmonary ARDS was associated with higher IL6 and IL8 levels compared with pulmonary ARDS. Mechanical ventilation with positive end-expiratory pressure ≥ 15 cmH2O before ECMO was associated with higher IL6, IL8 and TNFα levels. Driving pressures ≥ 19 cmH2O before ECMO were associated with higher IL8 levels. Non-survivors had higher IL6 and IL8 levels for the duration of ECMO. CONCLUSION: Cytokine levels, on average, fall rapidly after initiation of VV ECMO, which may be related to the reduction of invasiveness of mechanical ventilation. Higher cytokine levels are associated with extrapulmonary causes of ARDS, more aggressive mechanical ventilation before VV ECMO, and mortality.

Pitfalls in percutaneous ECMO cannulation.

INTRODUCTION: This observational report depicts typical problems of extracorporeal membrane oxygenation cannulation from a large case series of a single center. METHODS: We analysed our experience with 720 consecutive patients receiving veno-venous or veno-arterial extracorporeal membrane oxygenation focusing on the spectrum of complications occurring in a subset of 159 patients treated with percutaneous veno-arteria extracorporeal membrane oxygenation in our institution between January 2009 to December 2014. RESULTS: The main problems were: vascular complications or ischemia of the corresponding extremity (leading to surgical revision in 16.9 % of patients); blood loss and/or relocation of cannulas. Hypoxia of the upper body (Harlequin syndrome) occurred in 8.8 % of patients. Cannulation failure and malfunction were infrequent. Careful insertion technique, close surveillance and monitoring are compelling. CONCLUSIONS: As lack of experience is the trigger of many complications, adequate training of cannulation techniques is essential to minimize adverse events.

[Extracorporeal pulmonary support procedures in intensive care medicine 2014]. / Extrakorporale Lungenunterstützungsverfahren in der Intensivmedizin 2014.

BACKGROUND: In recent years a rapid expansion of extracorporeal devices for support of severe lung failure has been witnessed. Systems for veno-venous extracorporeal membrane oxygenation (VV-ECMO) or for extracorporeal carbon dioxide elimination are distinguished depending on the indications. OBJECTIVES: The state of the art of extracorporeal lung support is presented with an overview of the different systems, the indications, efficiency and potential side effects. METHODS: By means of a selective literature research and based on personal experience, the principles and techniques, efficiency and potential side-effects of the new modalities are described. RESULTS: The VV-ECMO systems may be indicated in severe, refractory and predominantly hypoxemic lung failure (pAO2/FIO2 <80 mmHg). Both life-saving gas exchange and a reduction of ventilator-induced lung injury by means of a more protective ventilation can be achieved. Experienced centers can obtain survival rates of more than 60%. Either pumpless arterio-venous devices, also called interventional lung assist (ILA) or low-flow ECMO devices can be used for extracorporeal carbon dioxide elimination in refractory respiratory acidosis. Severe complications can occur with all modalities of extracorporeal support and have to be rapidly recognized and controlled. It must be pointed out that secure evidence based on prospective randomized studies is currently limited for all modalities. CONCLUSION: Modern extracorporeal lung support devices allow an effective extracorporeal gas exchange and have become an inherent component of intensive care treatment of critically ill patients. Due to potentially severe complications the use should be restricted to specialized centers with experience in the treatment of severe acute respiratory distress syndrome (ARDS).

Pandemic and post-pandemic influenza A (H1N1) seasons in a tertiary care university hospital-high rate of complications compared to previous influenza seasons.

INTRODUCTION: The aim was to study the characteristics and case severity of patients hospitalized for influenza with a pandemic strain at a German tertiary care university hospital in 2009/10 and 2010/11 and to compare them to two previous influenza seasons. METHODS: An observational study of all patients hospitalized for laboratory-confirmed influenza during the last four influenza seasons at Regensburg University Hospital was undertaken. RESULTS: During the last four seasons, a rising number of patients were admitted due to influenza (4 in 2007/8, 16 in 2008/9, 27 in 2009/10, and 55 in 2010/11). Patients seen in the last two seasons were younger (median age 63 years in 2007/8, 52 years in 2008/9, 42 years in 2009/10, and 48 years in 2010/11) (p = 0.046) and presented with a lower rate of major comorbidities (75 % in 2007/8, 62.5 % in 2008/9, 37 % in 2009/10, and 47.3 % in 2010/11). The pandemic and post-pandemic seasons were characterized by a high rate of seriously ill patients with longer hospitalizations (11 days in 2007/8, 7 days in 2008/9, 22 days in 2009/10 and 2010/11) (p = 0.004) and higher rates of intensive care unit (ICU) admission (25 % in 2007/8, 18.8 % in 2008/9, 66.7 % in 2009/10, and 52.7 % in 2010/11) (p = 0.003) and mechanical ventilation (25 % in 2007/8, 6.3 % in 2008/9, 63 % in 2009/10, and 49.1 % in 2010/11) (p < 0.001). Extracorporeal membrane oxygenation (ECMO) was necessary in 33.3 % of patients in 2009/10 and 25.5 % in 2010/11. We had six fatalities in both pandemic and post-pandemic seasons. CONCLUSION: Compared to seasonal influenza, we observed even more so in the post-pandemic than the pandemic season a higher number of younger patients, with less serious comorbidities often showing a very severe course.

First experience with the new portable extracorporeal membrane oxygenation system Cardiohelp for severe respiratory failure in adults.

BACKGROUND: Over the last decade, technical improvements in extracorporeal membrane oxygenation (ECMO) equipment have reduced procedure-related complications and have made ECMO an effective option for patients with acute respiratory distress syndrome (ARDS) if conventional therapy fails. METHODS: In this report, we present our early experience with the Cardiohelp, a new portable miniaturized ECMO system, in 22 consecutive patients with ARDS. All patients were placed on venovenous ECMO. Cannulas were inserted percutaneously, employing the Seldinger technique. Data were collected prospectively. RESULTS: The median patient age was 47 years (36 to 61). Fifteen patients from regional hospitals were too unstable for conventional transport and were placed on Cardiohelp at the referring hospital and then transported to our institution. The patients were transported by ambulance (n=2) or helicopter (n=13) over a distance of 50-250 km. Cardiohelp support resulted in immediate improvement of gas exchange and highly protective ventilation. The median duration of support was 13 days (8 to 19). An exchange of the device was necessary in 9 patients. Sixteen patients (72.7%) were successfully weaned from ECMO and fifteen patients (68.2%) survived. Device-related complications were not observed. CONCLUSIONS: The compact portable ECMO device Cardiohelp is a highly effective method to secure vital gas exchange and to reduce further ventilator-induced lung injury in patients with acute respiratory failure. Crucial technical innovations and ease of device transport and implantation allow location-independent stabilization with consecutive inter-hospital transfer.

First application of a new portable, miniaturized system for extracorporeal membrane oxygenation.

Extracorporeal assist systems for respiratory and circulatory failure are increasingly used in intensive care medicine. Important technical innovations over the past years have resulted in improved biocompatibility and, consequently, reduced complication rates. Extracorporeal membrane oxygenation (ECMO) technology experienced a surge of use during the influenza A (H1N1) pandemic, but transport of unstable patients with life-threatening ARDS is still hazardous. We describe the first successful application of a newly developed, compact and easily portable ECMO device in a patient with severe ARDS due to influenza A (H1N1). Support with the miniaturized ECMO resulted in immediate improvement of gas exchange and a highly protective ventilation. Inspiratory pressure was decreased from 40 to 29 cmH(2)O and tidal volume per kilogram of predicted bodyweight could be reduced from 6.5 to 3.3 mL. Small and efficient heart-lung assist systems will become a tool of growing importance in intensive care medicine, both for profound respiratory and cardiac failure in the future. The reduced weight and compact design of the device greatly facilitates transport and handling of unstable patients on ECMO.

Fatal Pseudomonas aeruginosa pneumonia in a previously healthy woman was most likely associated with a contaminated hot tub.

Community-acquired pneumonia due to Pseudomonas aeruginosa in previously healthy individuals is a rare disease that is associated with high fatality. On 14 February 2010 a previously healthy 49-year-old woman presented to an emergency room with signs and symptoms of pneumonia, 2 days after returning from a spa holiday in a wellness hotel. Blood cultures and respiratory specimens grew P. aeruginosa. Despite adequate antimicrobial therapy, the patient died of septic multiorgan failure on day nine of hospitalization. On February 26, nine water samples were taken from the hotel facilities used by the patient: In the hot tub sample 37,000 colony-forming units of P. aeruginosa/100 ml were detected. Two of five individual colonies from the primary plate used for this hot tub water sample were found to be genetically closely related to the patient's isolates. Results from PFGE, AFLP and MLST analysis allowed the two lung isolates gained at autopsy and the whirlpool bathtub isolates to be allocated into one cluster. The patient most likely acquired P. aeruginosa from the contaminated water in the hotel's hot tub. The detection of P. aeruginosa in high numbers in a hot tub indicates massive biofilm formation in the bath circulation and severe deficiencies in hygienic maintenance. The increasing popularity of hot tubs in hotels and private homes demands increased awareness about potential health risks associated with deficient hygienic maintenance.

Extracorporeal pumpless interventional lung assist in clinical practice: determinants of efficacy.

Respiratory acidosis can become a serious problem during protective ventilation of severe lung failure. A pumpless arteriovenous interventional lung assist (iLA) for extracorporeal carbon dioxide removal has been used increasingly to control critical respiratory situations. The present study sought to evaluate the factors determining the efficacy of iLA and calculate its contribution to gas exchange. In a cohort of 96 patients with severe acute respiratory distress syndrome, haemodynamic parameters, oxygen consumption and carbon dioxide production as well as gas transfer through the iLA were analysed. The measurements demonstrated a significant dependency of blood flow via the iLA device on cannula size (mean+/-sd 1.59+/-0.52 L x min(-1) for 15 French (Fr), 1.94+/-0.35 L x min(-1) for 17 Fr, and 2.22 +/-0.45 L x min(-1) for 19 Fr) and on mean arterial pressure. Oxygen transfer capacity averaged 41.7+/-20.8 mL x min(-1), carbon dioxide removal was 148.0+/-63.4 mL x min(-1). Within two hours of iLA treatment, arterial oxygen partial pressure/inspired oxygen fraction ratio increased significantly and a fast improvement in arterial carbon dioxide partial pressure and pH was observed. Interventional lung assist eliminates approximately 50% of calculated total carbon dioxide production with rapid normalisation of respiratory acidosis. Despite limited contribution to oxygen transfer it may allow a more protective ventilation in severe respiratory failure.