Abstract
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.
Careful patient selection is the prerequisite to raise transplant benefit. In lung transplant (LT) candidates, the effect of body mass index (BMI) on postoperative outcome remains controversial, ...possibly due to the inaccuracy of BMI in discriminating between fat and muscle mass. We therefore hypothesized that assessment of body composition by muscle mass measures is more accurate than by BMI regarding postoperative outcome.
All LT recipients from 2011 to 2014 were included and retrospectively analyzed. Lean psoas area (LPA) was assessed from pretransplant computed tomography scans, and associations with postoperative outcomes were investigated.
Included were 103 consecutive LT recipients with a mean pre-LT BMI of 22.0 ± 4.0 kg/m(2) and a mean LPA of 22.3 ± 8.3 cm(2). LPA was inversely associated with length of mechanical ventilation (p = 0.03), requirement of tracheostomy (p = 0.035), and length of stay in the intensive care unit (p = 0.02), while controlling for underlying disease, BMI, sex, age, and procedure; in contrast, BMI was not (p = 0.25, p = 0.54, and p = 0.42, respectively.). Multiple regression analysis revealed that the 6-minute walk distance at the end of pulmonary rehabilitation was significantly associated with LPA (p = 0.02).
LPA can easily be assessed in LT candidates as part of pretransplant evaluation and was significantly associated with short-term outcome, whereas BMI was not. Assessment of LPA may provide additional information on body composition beyond BMI. However, the clinical utility has to be further evaluated.
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.
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 (CLCR
). 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
, 50%T
) 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 CLCR
on meropenem concentrations and target attainment and developed a tool for risk assessment of target non-attainment.
Large inter- and intra-patient variability in meropenem concentrations was observed in the critically ill population (n = 48). Attainment of the target 100%T
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
. A hyperbolic relationship between CLCR
(25-255 ml/minute) and meropenem serum concentrations at the end of the dosing interval (C
) 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).
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.
Clinicaltrials.gov, NCT01793012 . Registered on 24 January 2013.
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.
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.
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.
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.
Clinicaltrials.gov NCT01793012. Registered 24 January 2013.
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.).
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.
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.
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).
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).
The purpose of this study was to examine the effect of an inpatient rehabilitation program on health-related quality of life (HRQOL) and exercise capacity (EC) in long-term (>1 year after lung ...transplantation) survivors (LTSs) in comparison to a control group (CG).
Sixty LTSs, 4.5 ± 3.2 years after lung transplantation (LTx), were randomly assigned to two equally sized groups that were stratified for gender and underlying disease. Thirty LTSs (age 49 ± 13 years, 13 male and 17 females, 19 double LTxs, 7 BOS Stage ≥ 1) attended an inpatient rehabilitation program (intervention group, IG) for 23 ± 5 days. The CG (age 50 ± 12 years, 13 males and 17 females, 20 double LTxs, 2 BOS Stage ≥ 1) received medical standard therapy (physiotherapy). Patients were evaluated by cardiopulmonary exercise testing, 6-minute walk test (6MWT), SF-36, SGRQ and the Quality of Life Profile for Chronic Diseases questionnaire before and after (18 ± 3 days) the program.
The groups were statistically indistinguishable in terms of clinical data. Each treatment group significantly improved their sub-maximal EC (6MWT: IG, 493 ± 90 m vs 538 ± 90 m, p < 0.001; CG, 490 ± 88 m vs 514 ± 89 m, p < 0.001) and maximal EC (VO(2peak): IG, 17.0 vs 18.5 ml/min/kg, p = 0.039; CG, 18.0 vs 19.5 ml/min/kg, p = 0.005), without reaching statistical significance between the groups. In both study groups, patients HRQOL tended to improve. Significant correlations were found between EC parameters and HRQOL scales.
Our data suggest that structured physical training may improve exercise tolerance in LTS. Our study results did not demonstrate a significant benefit of an inpatient over an outpatient exercise program.
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.
To provide guidance and recommendations ...for the requirements of (infra)structure, personal, and organization of intensive care units.
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.
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.
This document provides a detailed framework for organizing and planning the operation and construction/renovation of ICUs.
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.
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.
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).
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.
The strong interest of stakeholder for successful liver transplants is inadequately translated into current allocation rules.
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