Quantification of Adipose Tissue and Muscle Mass Based on Computed Tomography Scans: Comparison of Eight Planimetric and Diametric Techniques Including a Step-By-Step Guide.

BACKGROUND: Recent scientific work proved that knowledge about body composition beyond the body mass index is essential. Both adipose tissue and muscular status are determining risk factors of morbidity and mortality. Analysis of single cross-sectional computed tomography (CT) images, acquired during routine care only to prevent additional radiation exposure, provide a detailed insight into the body composition of chronically and critically ill patients. METHODS: This retrospective study included 490 trauma patients of whom a whole-body multiple detector CT scan was acquired at admission. From a single cross-sectional CT, we compared eight diametric and planimetric techniques for the assessment of core muscle mass as well as visceral and subcutaneous adipose tissue. Furthermore, we derived formulas for converting the measurement results of various techniques into each other. RESULTS: For intra- and interobserver reliability, we obtained intraclass correlation coefficients (ICCs) ranging from 0.947 to 0.997 (intraobserver reliability) and from 0.850 to 0.998 (interobserver reliability) for planimetric measurements. Diametric techniques conferred lower ICCs with 0.851-0.995 and 0.833-0.971, respectively. Overall, area-based measurements of abdominal adipose tissue yielded highly correlated results with diametric measures of obesity. For example, the Pearson correlation of visceral adipose tissue and sagittal abdominal diameter was 0.87 for male and 0.82 for female patients. Planimetric and diametric muscle measurements correlated best for lean psoas area and bilateral diametric measurement of the psoas with a Pearson correlation of 0.90 and 0.93 for male and female patients, respectively. CONCLUSION: Planimetric measurements should remain the gold standard to describe fat and muscle compartments. Diametric measurements could however serve as a surrogate if planimetric techniques are not readily available or feasible as for example in large registries.

Benefit in liver transplantation: a survey among medical staff, patients, medical students and non-medical university staff and students.

BACKGROUND: The allocation of any scarce health care resource, especially a lifesaving resource, can create profound ethical and legal challenges. Liver transplant allocation currently is based upon urgency, a sickest-first approach, and does not utilize capacity to benefit. While urgency can be described reasonably well with the MELD system, benefit encompasses multiple dimensions of patients' well-being. Currently, the balance between both principles is ill-defined. METHODS: This survey with 502 participants examines how urgency and benefit are weighted by different stakeholders (medical staff, patients on the liver transplant list or already transplanted, medical students and non-medical university staff and students). RESULTS: Liver transplant patients favored the sickest-first allocation, although all other groups tended to favor benefit. Criteria of a successful transplantation were a minimum survival of at least 1 year and recovery of functional status to being ambulatory and capable of all self-care (ECOG 2). An individual delisting decision was accepted when the 1-year survival probability would fall below 50%. Benefit was found to be a critical variable that may also trigger the willingness to donate organs. CONCLUSIONS: The strong interest of stakeholder for successful liver transplants is inadequately translated into current allocation rules.

Optimization of linezolid therapy in the critically ill: the effect of adjusted infusion regimens.

Objectives: Insufficient linezolid levels, which are associated with a poorer outcome, are often observed in ICU patients who receive standard dosing. Although strategies to overcome these insufficient levels have been discussed, appropriate alternative dosing regimens remain to be identified. Methods: Various infusion regimens (1200-3600 mg/day; q6h, q8h, q12h and continuous) were simulated in 67 000 ICU patients. The probability of attaining pharmacodynamic targets ( T >MIC ≥85%, AUC/MIC ≥100, cumulative fraction of response for Staphylococcus aureus and Enterococcus spp., PTA for an MIC of 0.5-4 mg/L) as well as the avoidance of toxic concentrations and concentrations constantly below the MIC (lack of antibiotic effect) or inside a mutant selection window (resistance development) were evaluated. Results: Best target attainment according to T >MIC was observed for continuous infusions, followed by q6h, q8h and q12h. A substantially reduced target attainment was observed in patients with acute respiratory distress syndrome (ARDS). In patients without ARDS, 1200 mg/day was insufficient irrespective of the regimen, while a dose of 1400 mg/day administered q6h or by continuous infusions provided an acceptable target attainment (e.g. cumulative fraction of response with regards to T >MIC ≥93%). Higher rates of potentially toxic trough concentrations (28% versus 12%) and concentrations constantly inside the mutant selection window (15% versus <0.1%) were observed with continuous infusions compared with q6h infusions (1400 mg/day, patients without ARDS). Conclusions: Irrespective of the regimen, 1200 mg/day linezolid might be insufficient for the treatment of ICU patients. Patients without ARDS might particularly benefit from q6h infusions with increased daily doses (e.g. 1400 mg/day).

Role of renal function in risk assessment of target non-attainment after standard dosing of meropenem in critically ill patients: a prospective observational study.

BACKGROUND: Severe bacterial infections remain a major challenge in intensive care units because of their high prevalence and mortality. Adequate antibiotic exposure has been associated with clinical success in critically ill patients. The objective of this study was to investigate the target attainment of standard meropenem dosing in a heterogeneous critically ill population, to quantify the impact of the full renal function spectrum on meropenem exposure and target attainment, and ultimately to translate the findings into a tool for practical application. METHODS: A prospective observational single-centre study was performed with critically ill patients with severe infections receiving standard dosing of meropenem. Serial blood samples were drawn over 4 study days to determine meropenem serum concentrations. Renal function was assessed by creatinine clearance according to the Cockcroft and Gault equation (CLCRCG). Variability in meropenem serum concentrations was quantified at the middle and end of each monitored dosing interval. The attainment of two pharmacokinetic/pharmacodynamic targets (100%T>MIC, 50%T>4×MIC) was evaluated for minimum inhibitory concentration (MIC) values of 2 mg/L and 8 mg/L and standard meropenem dosing (1000 mg, 30-minute infusion, every 8 h). Furthermore, we assessed the impact of CLCRCG on meropenem concentrations and target attainment and developed a tool for risk assessment of target non-attainment. RESULTS: Large inter- and intra-patient variability in meropenem concentrations was observed in the critically ill population (n = 48). Attainment of the target 100%T>MIC was merely 48.4% and 20.6%, given MIC values of 2 mg/L and 8 mg/L, respectively, and similar for the target 50%T>4×MIC. A hyperbolic relationship between CLCRCG (25-255 ml/minute) and meropenem serum concentrations at the end of the dosing interval (C8h) was derived. For infections with pathogens of MIC 2 mg/L, mild renal impairment up to augmented renal function was identified as a risk factor for target non-attainment (for MIC 8 mg/L, additionally, moderate renal impairment). CONCLUSIONS: The investigated standard meropenem dosing regimen appeared to result in insufficient meropenem exposure in a considerable fraction of critically ill patients. An easy- and free-to-use tool (the MeroRisk Calculator) for assessing the risk of target non-attainment for a given renal function and MIC value was developed. TRIAL REGISTRATION: Clinicaltrials.gov, NCT01793012 . Registered on 24 January 2013.

Predicting the Necessity for Extracorporeal Circulation During Lung Transplantation: A Feasibility Study.

OBJECTIVE: The factors leading to the implementation of unplanned extracorporeal circulation during lung transplantation are poorly defined. Consequently, the authors aimed to identify patients at risk for unplanned extracorporeal circulation during lung transplantation. DESIGN: Retrospective data analysis. SETTING: Single-center university hospital. PARTICIPANTS: A development data set of 170 consecutive patients and an independent validation cohort of 52 patients undergoing lung transplantation. INTERVENTIONS: The authors investigated a cohort of 170 consecutive patients undergoing single or sequential bilateral lung transplantation without a priori indication for extracorporeal circulation and evaluated the predictive capability of distinct preoperative and intraoperative variables by using automated model building techniques at three clinically relevant time points (preoperatively, after endotracheal intubation, and after establishing single-lung ventilation). MEASUREMENTS AND MAIN RESULTS: Preoperative mean pulmonary arterial pressure was the strongest predictor for unplanned extracorporeal circulation. A logistic regression model based on preoperative mean pulmonary arterial pressure and lung allocation score achieved an area under the receiver operating characteristic curve of 0.85. Consequently, the authors developed a novel 3-point scoring system based on preoperative mean pulmonary arterial pressure and lung allocation score, which identified patients at risk for unplanned extracorporeal circulation and validated this score in an independent cohort of 52 patients undergoing lung transplantation. CONCLUSIONS: The authors showed that patients at risk for unplanned extracorporeal circulation during lung transplantation could be identified by their novel 3-point score.

Predictors of Inadequate Linezolid Concentrations after Standard Dosing in Critically Ill Patients.

Adequate linezolid blood concentrations have been shown to be associated with an improved clinical outcome. Our goal was to assess new predictors of inadequate linezolid concentrations often observed in critically ill patients. Fifty-two critically ill patients with severe infections receiving standard dosing of linezolid participated in this prospective observational study. Serum samples (median, 32 per patient) were taken on four consecutive days, and total linezolid concentrations were quantified. Covariates influencing linezolid pharmacokinetics were identified by multivariate analysis and a population pharmacokinetic model. Target attainment (area under the concentration-time curve over 12 h [AUC12]/MIC ratio of >50; MIC = 2 mg/liter) was calculated for both the study patients and a simulated independent patient group (n = 67,000). Target attainment was observed for only 36% of the population on both days 1 and 4. Independent covariates related to significant decreases of linezolid concentrations included higher weight, creatinine clearance rates, and fibrinogen and antithrombin concentrations, lower concentrations of lactate, and the presence of acute respiratory distress syndrome (ARDS). Linezolid clearance was increased in ARDS patients (by 82%) and in patients with elevated fibrinogen or decreased lactate concentrations. In simulated patients, most covariates, including fibrinogen and lactate concentrations and weight, showed quantitatively minor effects on target attainment (difference of ≤9% between the first and fourth quartiles of the respective parameters). In contrast, the presence of ARDS had the strongest influence, with only ≤6% of simulated patients reaching this target. In conclusion, the presence of ARDS was identified as a new and strong predictor of insufficient linezolid concentrations, which might cause treatment failure. Insufficient concentrations might also be a major problem in patients with combined alterations of other covariate parameters. (This study has been registered at ClinicalTrials.gov under registration number NCT01793012.).

Effects of biobanking conditions on six antibiotic substances in human serum assessed by a novel evaluation protocol.

BACKGROUND: Although therapeutic drug monitoring (TDM) for antibiotics in critically ill patients is recommended by expert panels, no commercial tests are available for most antibiotics. Therefore, we previously developed a multi-analyte method for the quantification of piperacillin, tazobactam, cefepime, meropenem, ciprofloxacin and linezolid in serum. However, limited stability data were available, and the relevant studies did not address the coefficients of variation of the methods applied, which may be important for verifying the storage dependency of the observed effects. Here we aimed to evaluate the storage effects of antibiotics by applying a novel evaluation protocol. METHODS: Serum-based test samples were aliquoted and stored at room temperature, 4 °C, -20 °C or -80 °C for up to 180 days. Using an innovative evaluation protocol (considering the coefficient of variation, p-value, and criterion of monotony of observed changes), we assessed whether relevant changes (defined as ≥15% in comparison with baseline) were storage dependent (defined as substantial changes). RESULTS: Storage at -80 °C for up to 180 days did not lead to substantial changes for any analyte. In contrast, storage at -20 °C induced substantial decreases after ≥7 days for piperacillin, tazobactam, cefepime and meropenem; after 90 days at -20 °C, only ≤23% of the initial concentrations were found for these parameters. No substantial changes were observed for linezolid and ciprofloxacin at any storage condition. All of the observed substantial changes were monotonic decreases. CONCLUSIONS: We recommend a storage temperature of -80 °C for ß-lactam antibiotics. The applied evaluation protocol yielded conclusive results and may be generally useful for stability studies.

Piperacillin concentration in relation to therapeutic range in critically ill patients--a prospective observational study.

BACKGROUND: Piperacillin levels after standard dosing have been shown frequently to be subtherapeutic, especially when renal clearance was augmented. Here, we aimed to determine if piperacillin was in its therapeutic range in a typically heterogeneous intensive care unit patient group, and also to describe target attainment dependent on daily dosage, creatinine clearance, and renal replacement therapy (RRT). METHODS: Sixty patients with severe infections were included in this monocentric prospective observational study. Patients received 4.5 g of piperacillin-tazobactam two to three times daily by intermittent infusion depending on renal function according to clinical guidelines. Over 4 days, multiple serum samples (median per patient, 29; in total, 1627) were obtained to determine total piperacillin concentrations using ultra-high-performance liquid chromatography/tandem mass spectrometry. RESULTS: A high heterogeneity of patient characteristics was observed (e.g., on day 1: creatinine clearance 2-233 mL/min and ten patients on RRT). Piperacillin trough levels showed inter-individual variation from 123 to >1785-fold on different study days. Each day, approximately 50% and 60% of the patients had piperacillin levels below the target ranges 1 and 2, respectively [defined for the calculated unbound piperacillin fraction according to the literature as 100% time above MIC (100%fT > MIC) (target range 1) and ≥ 50%fT > 4 × MIC (target range 2); MIC = 16 mg/L]. Whereas only the minority of patients who received piperacillin-tazobactam three times daily (TID) reached target 1 (38% on day 1), most patients who received piperacillin-tazobactam only twice daily (BID) because of severely impaired renal function reached this target (100% on day 1). Patients with RRT had significant higher percentages of fT > MIC. Zero percent, 55% and 100% of patients without RRT who received antibiotics TID reached target 1 when creatinine clearance was > 65 mL/min, 30-65 mL/min and < 30 mL/min, respectively. In patients with causative strains only sensitive to piperacillin-tazobactam of all antibiotics given to the patient, piperacillin levels negatively correlated with CRP concentrations of day 4 (p < 0.05). CONCLUSIONS: A dosage of 4.5 g piperacillin-tazobactam TID seems to be frequently insufficient in critically ill patients, and also in patients where renal function is mildly to moderately impaired. For these patients, prescription of 4.5 g piperacillin-tazobactam four times daily could be considered. TRIAL REGISTRATION: Clinicaltrials.gov NCT01793012. Registered 24 January 2013.

Rescue management of early complications after liver transplantation-key for the long-term success.

PURPOSE: Postoperative complications may have not only immediate but also long-term effects on the outcomes. Here, we analyzed the effect of postoperative complications requiring a reoperation (grade 3b) within the first 30 days on patients' and graft survival following liver transplantation. METHODS: Graft and patient survival in relation to donor and recipient variables and the need of reoperation for complications of 277 consecutive liver transplants performed from January 2007 to December 2012 were analyzed. RESULTS: Two hundred seventy-seven liver transplants were performed in 252 patients. Overall patient and graft survival at 1, 2, and 3 years were significantly reduced in patients requiring a reoperation. The labMELD score was significantly elevated (p = 0.04) and cold ischemia time was prolonged (p = 0.03) in recipients undergoing reoperations. Kaplan-Meier curves indicate that complications impact the outcome primarily within the first 3 months after transplantation. In multivariate analyses, the actual need of reoperation (p < 0.001), the labMELD score (p = 0.05), cold ischemia time (p = 0.02), and the need for hemodialysis pre-transplant (p = 0.05) were the only variables which correlated with the overall survival. CONCLUSION: Postoperative complications resulting in reoperations have a significant impact on the outcome primarily in the early phase after liver transplantation. Successful management of postoperative complications is key to every successful liver transplant program.

Quantification of piperacillin, tazobactam, cefepime, meropenem, ciprofloxacin and linezolid in serum using an isotope dilution UHPLC-MS/MS method with semi-automated sample preparation.

BACKGROUND: Recent studies have demonstrated highly variable blood concentrations of piperacillin, tazobactam, cefepime, meropenem, ciprofloxacin and linezolid in critically ill patients with a high incidence of sub-therapeutic levels. Consequently, therapeutic drug monitoring (TDM) of these antibiotics has to be considered, requiring robust and reliable routine analytical methods. The aim of the present work was to develop and validate a multi-analyte ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous quantification of the above mentioned antibiotics. METHODS: Sample preparation included a manual protein precipitation step followed by two-dimensional ultra high performance liquid chromatography (2D-UHPLC). Corresponding stable isotope-labeled substances were used as internal standards for all of the analytes, with the exception of tazobactam. The injected sample volume was 7 µL. The run time was 5.0 min. RESULTS: Inaccuracy was ≤8% and imprecision coefficient of variation (CV) was <9% for all analytes. Only minor matrix effects and negligible carry-over was observed. The method was found to be robust during the validation period. CONCLUSIONS: We were able to develop a reliable 2D-UHPLC-MS/MS method addressing analytes with highly heterogeneous physico-chemical properties. The novel assay may be an efficient tool for an optimized process workflow in clinical laboratories for important antibiotics in regards to TDM.

Variability of linezolid concentrations after standard dosing in critically ill patients: a prospective observational study.

INTRODUCTION: Severe infections in intensive care patients show high morbidity and mortality rates. Linezolid is an antimicrobial drug frequently used in critically ill patients. Recent data indicates that there might be high variability of linezolid serum concentrations in intensive care patients receiving standard doses. This study was aimed to evaluate whether standard dosing of linezolid leads to therapeutic serum concentrations in critically ill patients. METHODS: In this prospective observational study, 30 critically ill adult patients with suspected infections received standard dosing of 600 mg linezolid intravenously twice a day. Over 4 days, multiple serum samples were obtained from each patient, in order to determine the linezolid concentrations by liquid chromatography tandem mass spectrometry. RESULTS: A high variability of serum linezolid concentrations was observed (range of area under the linezolid concentration time curve over 24 hours (AUC24) 50.1 to 453.9 mg/L, median 143.3 mg*h/L; range of trough concentrations (Cmin) < 0.13 to 14.49 mg/L, median 2.06 mg/L). Furthermore, potentially subtherapeutic linezolid concentrations over 24 hours and at single time points (defined according to the literature as AUC24 < 200 mg*h/L and Cmin < 2 mg/L) were observed for 63% and 50% of the patients, respectively. Finally, potentially toxic levels (defined as AUC24 > 400 mg*h/L and Cmin > 10 mg/L) were observed for 7 of the patients. CONCLUSIONS: A high variability of linezolid serum concentrations with a substantial percentage of potentially subtherapeutic levels was observed in intensive care patients. The findings suggest that therapeutic drug monitoring of linezolid might be helpful for adequate dosing of linezolid in critically ill patients. TRIAL REGISTRATION: Clinicaltrials.gov NCT01793012. Registered 24 January 2013.

Parameters associated with short- and midterm survival in bridging to lung transplantation with extracorporeal membrane oxygenation.

Patients with terminal lung failure may be bridged to lung transplantation (LTX) by extracorporeal membrane oxygenation (ECMO). With the present shortage of donor organs and the high level of invasiveness of ECMO treatment, appropriate selection criteria for bridge to transplant need to be defined. We report retrospective data from 26 patients on ECMO listed for LTX. Seven patients were successfully transplanted (LTX-s). Six patients survived until transplantation, but died intra- or post-operatively (LTX-ns). Thirteen patients died before transplantation (Fail). There was no difference between LTX-s and the 19 overall non-survivors (NS) prior to ECMO initiation with regard to demographic data or ventilator parameters except for higher PaO2 /FiO2 in the LTX-s. Time on ECMO pre-LTX did not differ in the LTX-s and LTX-ns groups. SOFA score was lower in LTX-s when compared to LTX-ns before ECMO (p = 0.0155), during bridging (p = 0.028), and right before transplantation (p = 0.0038). Maximal bilirubin during bridging and bilirubin prior to transplantation was markedly elevated in the LTX-ns group [4.2 (2.4-4.7) vs. 1.1 (0.8-2.0) mg/dL; p = 0.0266 and 1.6 (1.2-3.0) vs. 0.5 (0.5-0.5) mg/dL; p = 0.0047). Bridging to LTX is a challenging but viable option for selected patients. Special consideration should be given to hepatic function.

Hand hygiene compliance in the intensive care unit: Hand hygiene and glove changes.

BACKGROUND: Hand disinfection (HD) is known to be the single most effective prevention measure to avoid nosocomial infections, but the compliance rate (CR) remains low. The aim of this study was to determine the incidence of HD opportunities and the CR during the treatment of critically ill patients. One special focus was on glove usage to determine whether gloves were substituted for HD. METHODS: This is a single-blinded direct observation of employees of an.ßintensive care unit. One specially educated observer recorded all hand hygiene indications over a period of 21 8-hour shifts as well as performed HD and study of glove use behavior. RESULTS: Over a period of 168.ßhours, 2,036 HDs should be performed during the care for 1 intensive care unit patient. In total, only 690 HDs occurred, resulting in a CR of 33.9%. With regard to the nurses, there was an HD opportunity around the clock every 6.ßminutes on average. About 17% of the total working time would have to be applied for 100% correct hand hygiene application. Donning or changing of gloves took place in 38.2% of all indications for HD. CONCLUSIONS: Our results show that HD opportunities occur in high frequency during the treatment of critically ill patients. The compliance with HD remains too low, even when a 100% CR seems to be unachievable. Improvements should focus on aseptic procedures, combining the lowest CR with the highest procedural risk for the patient. The Healthcare Personal (HCP) uses gloves when an HD opportunity occurs. Implementing glove disinfection strategies in daily routine might help optimize patient care.

Recommendations on the structure, personal, and organization of intensive care units.

Background: Intensive care units (ICU) are central facilities of medical care in hospitals world-wide and pose a significant financial burden on the health care system. Objectives: To provide guidance and recommendations for the requirements of (infra)structure, personal, and organization of intensive care units. Design and setting: Development of recommendations based on a systematic literature search and a formal consensus process from a group of multidisciplinary and multiprofessional specialists from the German Interdisciplinary Association of Intensive Care and Emergency Medicine (DIVI). The grading of the recommendation follows the report from an American College of Chest Physicians Task Force. Results: The recommendations cover the fields of a 3-staged level of intensive care units, a 3-staged level of care with respect to severity of illness, qualitative and quantitative requirements of physicians and nurses as well as staffing with physiotherapists, pharmacists, psychologists, palliative medicine and other specialists, all adapted to the 3 levels of ICUs. Furthermore, proposals concerning the equipment and the construction of ICUs are supplied. Conclusion: This document provides a detailed framework for organizing and planning the operation and construction/renovation of ICUs.

[DIVI-Recommendations on the infrastruture of adult intensive care units]. / DIVI-Empfehlung zur Struktur und Ausstattung von Intensivstationen 2022 (Erwachsene).

This document on the Structure and Equipment for Intensive Care Units of the German Association for Intensive and Emergency Care (DIVI) aims at providing guidance and recommendations for the requirements of (infra)structure, personal, and organization of intensive care units. The recommendations are based on a systematic literature search and a formal consensus process from a group of multi-disciplinary and multiprofessional specialists from the DIVI. The recommendations comprise a 3-staged level of intensive care units, a 3-staged level of care with respect to severity of illness, the staffing requirement of physicians, nurses, physiotherapists, pharmacists, psychologists, and other specialists. Furthermore, proposals concerning the equipment and the construction of ICUs are supplied.

The Munich-LTX-Score: predictor for survival after lung transplantation.

BACKGROUND: The purpose of this study was to create a prognostic score calculated one yr after LTX based on post-transplant factors inclusive of donor and recipient characteristics that could be used to predict long-term survival in patients after lung transplantation (LTX). METHODS: Uni- and multivariate analysis in 206 consecutive LTX patients identified independent risk factors for post-transplant mortality and onset of bronchiolitis obliterans syndrome. Munich-LTX-Score is devised by summing up each identified risk factor. RESULTS: Multivariate analyses revealed acute rejection, lymphocytic bronchiolitis, donor age ≥ 55 yr, and HLA-A ≥ 2-/DR ≥ 2 mismatch and single LTX to be independent negative predictors for long-term survival (p < 0.05). Munich-LTX-Score identified three discrete groups: low-, moderate-, and high risk. The actuarial five-yr survival after score calculation one yr after LTX of the entire cohort was 58%, compared with 91% in low-, 54% in moderate-, and 0% in the high-risk group (p < 0.001). CONCLUSION: Within our cohort of patients calculation of the Munich-LTX-Score, consisting of donor-, recipient-, and post-transplant characteristics, one yr after LTX allowed to predict long-term survival of lung transplant recipients. After prospective validation, this score could identify patients who may benefit from intensified surveillance after LTX.

Blood pressure measurement using only a smartphone.

Hypertension is an immense challenge in public health. As one of the most prevalent medical conditions worldwide, it is a major cause of premature death. At present, the detection, diagnosis and monitoring of hypertension are subject to several limitations. In this review, we conducted a literature search on blood pressure measurement using only a smartphone, which has the potential to overcome current limitations and thus pave the way for long-term ambulatory blood pressure monitoring on a large scale. Among the 333 articles identified, we included 25 relevant articles over the past decade (November 2011-November 2021) and analyzed the described approaches to the types of underlying data recorded with smartphone sensors, the signal processing techniques applied to construct the desired signals, the features extracted from the constructed signals, and the algorithms used to estimate blood pressure. In addition, we analyzed the validation of the proposed methods against reference blood pressure measurements. We further examined and compared the effectiveness of the proposed approaches. Among the 25 articles, 23 propose an approach that requires direct contact between the sensor and the subject and two articles propose a contactless approach based on facial videos. The sample sizes in the identified articles range from three to 3000 subjects, where 8 articles used sample sizes of 85 or more subjects. Furthermore, 10 articles include hypertensive subjects in their participant pools. The methodologies applied for the evaluation of blood pressure measurement accuracy vary considerably among the analyzed articles. There is no consistency regarding the methods for blood pressure data collection and the reference blood pressure measurement and validation. Moreover, no established protocol is currently available for the validation of blood pressure measuring technologies using only a smartphone. We conclude the review with a discussion of the results and with recommendations for future research on the topic.

Potential functional and survival benefit of double over single lung transplantation for selected patients with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a frequent indication for lung transplantation (LTX) with pulmonary hypertension (PH) negatively affecting outcome. The optimal procedure type remains a debated topic. The aim of this study was to evaluate the impact of pretransplant PH in IPF patients. Single LTX (SLTX, n = 46) was the standard procedure type. Double LTX (DLTX, n = 30) was only performed in cases of relevant PH or additional suppurative lung disease. There was no significant difference for pretransplant clinical parameters. Preoperative mean pulmonary arterial pressure was significantly higher in DLTX recipients (22.7 +/- 0.8 mmHg vs. 35.9 +/- 1.8 mmHg, P < 0.001). After transplantation, 6-min-walk distance and BEST-FEV(1) were significantly higher for DLTX patients (6-MWD: 410 +/- 25 m vs. 498 +/- 23 m, P = 0.02; BEST-FEV(1): 71.2 +/- 3.0 (% pred) vs. 86.2 +/- 4.2 (% pred), P = 0.004). Double LTX recipients demonstrated a significantly better 1-year-, overall- and Bronchiolitis obliterans Syndrome (BOS)-free survival (P < 0.05). Cox regression analysis confirmed SLTX to be a significant predictor for death and BOS. Single LTX offers acceptable survival rates for IPF patients. Double LTX provides a significant benefit in selected recipients. Our data warrant further trials of SLTX versus DLTX stratifying for potential confounders including PH.