Evaluating blood oxygen saturation measurements by popular fitness trackers in postoperative patients: A prospective clinical trial

Blood oxygen saturation is an important clinical parameter, especially in postoperative hospitalized patients, monitored in clinical practice by arterial blood gas (ABG) and/or pulse oximetry that both are not suitable for a long-term continuous monitoring of patients during the entire hospital stay, or beyond. Technological advances developed recently for consumer-grade fitness trackers could-at least in theory-help to fill in this gap, but benchmarks on the applicability and accuracy of these technologies in hospitalized patients are currently lacking. We therefore conducted at the postanaesthesia care unit under controlled settings a prospective clinical trial with 201 patients, comparing in total >1,000 oxygen blood saturation measurements by fitness trackers of three brands with the ABG gold standard and with pulse oximetry. Our results suggest that, despite of an overall still tolerable measuring accuracy, comparatively high dropout rates severely limit the possibilities of employing fitness trackers, particularly during the immediate postoperative period of hospitalized patients.

User Perceptions of Avatar-Based Patient Monitoring for Intensive Care Units: An International Exploratory Sequential Mixed-Methods Study

Visual Patient Avatar ICU is an innovative approach to patient monitoring, enhancing the user's situation awareness in intensive care settings. It dynamically displays the patient's current vital signs using changes in color, shape, and animation. The technology can also indicate patient-inserted devices, such as arterial lines, central lines, and urinary catheters, along with their insertion locations. We conducted an international, multi-center study using a sequential qualitative-quantitative design to evaluate users' perception of Visual Patient Avatar ICU among physicians and nurses. Twenty-five nurses and twenty-five physicians from the ICU participated in the structured interviews. Forty of them completed the online survey. Overall, ICU professionals expressed a positive outlook on Visual Patient Avatar ICU. They described Visual Patient Avatar ICU as a simple and intuitive tool that improved information retention and facilitated problem identification. However, a subset of participants expressed concerns about potential information overload and a sense of incompleteness due to missing exact numerical values. These findings provide valuable insights into user perceptions of Visual Patient Avatar ICU and encourage further technology development before clinical implementation.

Using Visual Patient to Show Vital Sign Predictions, a Computer-Based Mixed Quantitative and Qualitative Simulation Study

BACKGROUND

Machine learning can analyze vast amounts of data and make predictions for events in the future. Our group created machine learning models for vital sign predictions. To transport the information of these predictions without numbers and numerical values and make them easily usable for human caregivers, we aimed to integrate them into the Philips Visual-Patient-avatar, an avatar-based visualization of patient monitoring.

METHODS

We conducted a computer-based simulation study with 70 participants in 3 European university hospitals. We validated the vital sign prediction visualizations by testing their identification by anesthesiologists and intensivists. Each prediction visualization consisted of a condition (e.g., low blood pressure) and an urgency (a visual indication of the timespan in which the condition is expected to occur). To obtain qualitative user feedback, we also conducted standardized interviews and derived statements that participants later rated in an online survey.

RESULTS

The mixed logistic regression model showed 77.9% (95% CI 73.2-82.0%) correct identification of prediction visualizations (i.e., condition and urgency both correctly identified) and 93.8% (95% CI 93.7-93.8%) for conditions only (i.e., without considering urgencies). A total of 49 out of 70 participants completed the online survey. The online survey participants agreed that the prediction visualizations were fun to use (32/49, 65.3%), and that they could imagine working with them in the future (30/49, 61.2%). They also agreed that identifying the urgencies was difficult (32/49, 65.3%).

CONCLUSIONS

This study found that care providers correctly identified >90% of the conditions (i.e., without considering urgencies). The accuracy of identification decreased when considering urgencies in addition to conditions. Therefore, in future development of the technology, we will focus on either only displaying conditions (without urgencies) or improving the visualizations of urgency to enhance usability for human users.

High-dose methylprednisolone pulse therapy during refractory COVID-19 acute respiratory distress syndrome: a retrospective observational study

BACKGROUND

Current COVID-19 guidelines recommend the early use of systemic corticoids for COVID-19 acute respiratory distress syndrome (ARDS). It remains unknown if high-dose methylprednisolone pulse therapy (MPT) ameliorates refractory COVID-19 ARDS after many days of mechanical ventilation or rapid deterioration with or without extracorporeal membrane oxygenation (ECMO).

METHODS

This is a retrospective observational study. Consecutive patients with COVID-19 ARDS treated with a parenteral high-dose methylprednisolone pulse therapy at the intensive care units (ICU) of two University Hospitals between January 1st 2021 and November 30st 2022 were included. Clinical data collection was at ICU admission, start of MPT, 3-, 10- and 14-days post MPT.

RESULTS

Thirty-seven patients (mean age 55 ± 12 years) were included in the study. MPT started at a mean of 17 ± 12 days after mechanical ventilation. Nineteen patients (54%) received ECMO support when commencing MPT. Mean paO2/FiO2 significantly improved 3- (p = 0.034) and 10 days (p = 0.0313) post MPT. The same applied to the necessary FiO2 10 days after MPT (p = 0.0240). There were no serious infectious complications. Twenty-four patients (65%) survived to ICU discharge, including 13 out of 20 (65%) needing ECMO support.

CONCLUSIONS

Late administration of high-dose MPT in a critical subset of refractory COVID-19 ARDS patients improved respiratory function and was associated with a higher-than-expected survival of 65%. These data suggest that high-dose MPT may be a viable salvage therapy in refractory COVID-19 ARDS.

User Perceptions of Visual Blood: An International Mixed Methods Study on Novel Blood Gas Analysis Visualization

Blood gas analysis plays a central role in modern medicine. Advances in technology have expanded the range of available parameters and increased the complexity of their interpretation. By applying user-centered design principles, it is possible to reduce the cognitive load associated with interpreting blood gas analysis. In this international, multicenter study, we explored anesthesiologists' perspectives on Visual Blood, a novel visualization technique for presenting blood gas analysis results. We conducted interviews with participants following two computer-based simulation studies, the first utilizing virtual reality (VR) (50 participants) and the second without VR (70 participants). Employing the template approach, we identified key themes in the interview responses and formulated six statements, which were rated using Likert scales from 1 (strongly disagree) to 5 (strongly agree) in an online questionnaire. The most frequently mentioned theme was the positive usability features of Visual Blood. The online survey revealed that participants found Visual Blood to be an intuitive method for interpreting blood gas analysis (median 4, interquartile range (IQR) 4-4, p < 0.001). Participants noted that minimal training was required to effectively learn how to interpret Visual Blood (median 4, IQR 4-4, p < 0.001). However, adjustments are necessary to reduce visual overload (median 4, IQR 2-4, p < 0.001). Overall, Visual Blood received a favorable response. The strengths and weaknesses derived from these data will help optimize future versions of Visual Blood to improve the presentation of blood gas analysis results.

Avatar-based patient monitoring improves information transfer, diagnostic confidence and reduces perceived workload in intensive care units: computer-based, multicentre comparison study

Patient monitoring is the foundation of intensive care medicine. High workload and information overload can impair situation awareness of staff, thus leading to loss of important information about patients' conditions. To facilitate mental processing of patient monitoring data, we developed the Visual-Patient-avatar Intensive Care Unit (ICU), a virtual patient model animated from vital signs and patient installation data. It incorporates user-centred design principles to foster situation awareness. This study investigated the avatar's effects on information transfer measured by performance, diagnostic confidence and perceived workload. This computer-based study compared Visual-Patient-avatar ICU and conventional monitor modality for the first time. We recruited 25 nurses and 25 physicians from five centres. The participants completed an equal number of scenarios in both modalities. Information transfer, as the primary outcome, was defined as correctly assessing vital signs and installations. Secondary outcomes included diagnostic confidence and perceived workload. For analysis, we used mixed models and matched odds ratios. Comparing 250 within-subject cases revealed that Visual-Patient-avatar ICU led to a higher rate of correctly assessed vital signs and installations [rate ratio (RR) 1.25; 95% CI 1.19-1.31; P < 0.001], strengthened diagnostic confidence [odds ratio (OR) 3.32; 95% CI 2.15-5.11, P < 0.001] and lowered perceived workload (coefficient - 7.62; 95% CI - 9.17 to - 6.07; P < 0.001) than conventional modality. Using Visual-Patient-avatar ICU, participants retrieved more information with higher diagnostic confidence and lower perceived workload compared to the current industry standard monitor.

Visual Blood, Visualisation of Blood Gas Analysis in Virtual Reality, Leads to More Correct Diagnoses: A Computer-Based, Multicentre, Simulation Study

Interpreting blood gas analysis results can be challenging for the clinician, especially in stressful situations under time pressure. To foster fast and correct interpretation of blood gas results, we developed Visual Blood. This computer-based, multicentre, noninferiority study compared Visual Blood and conventional arterial blood gas (ABG) printouts. We presented six scenarios to anaesthesiologists, once with Visual Blood and once with the conventional ABG printout. The primary outcome was ABG parameter perception. The secondary outcomes included correct clinical diagnoses, perceived diagnostic confidence, and perceived workload. To analyse the results, we used mixed models and matched odds ratios. Analysing 300 within-subject cases, we showed noninferiority of Visual Blood compared to ABG printouts concerning the rate of correctly perceived ABG parameters (rate ratio, 0.96; 95% CI, 0.92–1.00; p = 0.06). Additionally, the study revealed two times higher odds of making the correct clinical diagnosis using Visual Blood (OR, 2.16; 95% CI, 1.42–3.29; p < 0.001) than using ABG printouts. There was no or, respectively, weak evidence for a difference in diagnostic confidence (OR, 0.84; 95% CI, 0.58–1.21; p = 0.34) and perceived workload (Coefficient, 2.44; 95% CI, −0.09–4.98; p = 0.06). This study showed that participants did not perceive the ABG parameters better, but using Visual Blood resulted in more correct clinical diagnoses than using conventional ABG printouts. This suggests that Visual Blood allows for a higher level of situation awareness beyond individual parameters’ perception. However, the study also highlighted the limitations of today’s virtual reality headsets and Visual Blood.

Attitudes of Anesthesiologists toward Artificial Intelligence in Anesthesia: A Multicenter, Mixed Qualitative-Quantitative Study

Artificial intelligence (AI) is predicted to play an increasingly important role in perioperative medicine in the very near future. However, little is known about what anesthesiologists know and think about AI in this context. This is important because the successful introduction of new technologies depends on the understanding and cooperation of end users. We sought to investigate how much anesthesiologists know about AI and what they think about the introduction of AI-based technologies into the clinical setting. In order to better understand what anesthesiologists think of AI, we recruited 21 anesthesiologists from 2 university hospitals for face-to-face structured interviews. The interview transcripts were subdivided sentence-by-sentence into discrete statements, and statements were then grouped into key themes. Subsequently, a survey of closed questions based on these themes was sent to 70 anesthesiologists from 3 university hospitals for rating. In the interviews, the base level of knowledge of AI was good at 86 of 90 statements (96%), although awareness of the potential applications of AI in anesthesia was poor at only 7 of 42 statements (17%). Regarding the implementation of AI in anesthesia, statements were split roughly evenly between pros (46 of 105, 44%) and cons (59 of 105, 56%). Interviewees considered that AI could usefully be used in diverse tasks such as risk stratification, the prediction of vital sign changes, or as a treatment guide. The validity of these themes was probed in a follow-up survey of 70 anesthesiologists with a response rate of 70%, which confirmed an overall positive view of AI in this group. Anesthesiologists hold a range of opinions, both positive and negative, regarding the application of AI in their field of work. Survey-based studies do not always uncover the full breadth of nuance of opinion amongst clinicians. Engagement with specific concerns, both technical and ethical, will prove important as this technology moves from research to the clinic.

Accuracy and Systematic Biases of Heart Rate Measurements by Consumer-Grade Fitness Trackers in Postoperative Patients: Prospective Clinical Trial

BACKGROUND

Over the recent years, technological advances of wrist-worn fitness trackers heralded a new era in the continuous monitoring of vital signs. So far, these devices have primarily been used for sports.

OBJECTIVE

However, for using these technologies in health care, further validations of the measurement accuracy in hospitalized patients are essential but lacking to date.

METHODS

We conducted a prospective validation study with 201 patients after moderate to major surgery in a controlled setting to benchmark the accuracy of heart rate measurements in 4 consumer-grade fitness trackers (Apple Watch 7, Garmin Fenix 6 Pro, Withings ScanWatch, and Fitbit Sense) against the clinical gold standard (electrocardiography).

RESULTS

All devices exhibited high correlation (r≥0.95; P<.001) and concordance (r_c≥0.94) coefficients, with a relative error as low as mean absolute percentage error <5% based on 1630 valid measurements. We identified confounders significantly biasing the measurement accuracy, although not at clinically relevant levels (mean absolute error<5 beats per minute).

CONCLUSIONS

Consumer-grade fitness trackers appear promising in hospitalized patients for monitoring heart rate.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05418881; https://www.clinicaltrials.gov/ct2/show/NCT05418881.

The Use of Non-Invasive Continuous Blood Pressure Measuring (ClearSight®) during Central Neuraxial Anaesthesia for Caesarean Section—A Retrospective Validation Study

The close monitoring of blood pressure during a caesarean section performed under central neuraxial anaesthesia should be the standard of safe anaesthesia. As classical oscillometric and invasive blood pressure measuring have intrinsic disadvantages, we investigated a novel, non-invasive technique for continuous blood pressure measuring. Methods: In this monocentric, retrospective data analysis, the reliability of continuous non-invasive blood pressure measuring using ClearSight^® (Edwards Lifesciences Corporation) is validated in 31 women undergoing central neuraxial anaesthesia for caesarean section. In addition, patients and professionals evaluated ClearSight^® through questioning. Results: 139 measurements from 11 patients were included in the final analysis. Employing Bland–Altman analyses, we identified a bias of −10.8 mmHg for systolic, of −0.45 mmHg for diastolic and of +0.68 mmHg for mean arterial blood pressure measurements. Pooling all paired measurements resulted in a Pearson correlation coefficient of 0.7 for systolic, of 0.67 for diastolic and of 0.75 for mean arterial blood pressure. Compensating the interindividual differences in linear regressions of the paired measurements provided improved correlation coefficients of 0.73 for systolic, of 0.9 for diastolic and of 0.89 for mean arterial blood pressure measurements. Discussion: Diastolic and mean arterial blood pressure are within an acceptable range of deviation from the reference method, according to the Association for the Advancement of Medical Instrumentation (AAMI) in the patient collective under study. Both patients and professionals prefer ClearSight^® to oscillometric blood pressure measurement in regard of comfort and handling.

[Postpartum hemorrhage : Interdisciplinary consideration in the context of patient blood management]

Postpartum hemorrhage (PPH) nowadays still represents a severe complication of both a vaginal delivery and a cesarean section. In German-speaking areas a new definition of the term has recently become established and the nomenclature with respect to the severe form of PPH was dropped. The handling of misoprostol as a uterotonic during treatment of PPH is also new, which is available in Germany only as a medical direct import. For adequate diagnostics and targeted treatment interdisciplinary and standardized algorithms should be established and the specialist disciplines involved should be sensitized to this problem. In addition to an adequate hemostasis, a developing coagulopathy must be recognized at an early stage and treated with targeted coagulation management. Through implementation concepts, particularly the second pillar (minimization of blood loss) and the third pillar (rational use of blood transfusions) of patient blood management, various aspects for improvement of treatment of a PPH can be identified.

[Patient blood management in the preparation for birth, obstetrics and postpartum period]

The implementation of patient blood management (PBM) is increasingly becoming standard in operative medicine. Recently, interest has also been shown for the vulnerable collective of pregnant women and neonates. As the information regarding anesthesiological procedures for pregnant women and the peripartum period including an informed consent process should be carried out long before childbirth, this provides a good possibility in this connection to incorporate PBM. An anesthesiological risk estimation as well as the diagnostic workup and treatment of potential anemia should be carried out during the pregnancy. Furthermore, loss of blood in anticipation of bleeding complications should be reduced by interdisciplinary preventive measures and an individually coordinated postpartum care should be organized. This results in an early diagnosis of anemia or iron deficiency with subsequent treatment also postpartum, analogous to the prepartum period.

[Peri- and Postoperative Anaemia Management]

Patient Blood Management (PBM) aims to diagnose and treat preoperative anaemia, avoid unnecessary blood loss, and enable rational use of blood products. Due to various limitations, treatment of preoperative anaemia has been successful in only a few German hospitals to date. Thus, the peri- and postoperative phase is increasingly becoming important for implementing various preventive and therapeutic measures for the treatment of (postoperative) anaemia. These will be comprehensively presented in the following.

Do Small Incisions Need Only Minimal Anesthesia?-Anesthetic Management in Laparoscopic and Robotic Surgery

Laparoscopic techniques have established themselves as a major part of modern surgery. Their implementation in every surgical discipline has played a vital part in the reduction of perioperative morbidity and mortality. Precise robotic surgery, as an evolution of this, is shaping the present and future operating theatre that an anesthetist is facing. While incisions get smaller and the impact on the organism seems to dwindle, challenges for anesthetists do not lessen and could even become more demanding than in open procedures. This review focuses on the pathophysiological effects of contemporary laparoscopic and robotic procedures and summarizes anesthetic challenges and strategies for perioperative management.

Ssp1, a site-specific parvulin homolog from Neurospora crassa active in protein folding

Peptidyl-prolyl cis-trans-isomerases (PPIases) are enzymes capable of isomerizing a Xaa-Pro peptide bond. Three families of PPIases are known: cyclophilins, FKBPs, and parvulins. The physiological functions of the PPIases are only poorly understood. Eucaryotic members of the parvulin family have recently been shown to be essential for regulation of mitosis. Here we describe the purification and characterization of Ssp1, an abundant parvulin homolog from Neurospora crassa, which is unique among the known eucaryotic parvulins in containing a polyglutamine stretch between the N-terminal WW domain and the C-terminal PPIase domain. Ssp1 is a site-specific PPIase with respect to the amino acid N-terminal to the proline residue. Peptides with glutamate, phosphoserine, or phosphothreonine in the -1-position proved to be the best substrates. Ssp1 is not only able to isomerize small peptides but is also active in protein folding, as shown with mouse dihydrofolate reductase. Using the substrate specificity of Ssp1, we could identify Glu81-Pro82 as a PPIase-sensitive site in folding of dihydrofolate reductase. These results demonstrate that Ssp1 is a potent mediator of protein folding and that parvulins can serve as tools to elucidate rate-limiting steps in protein folding reactions.

The Escherichia coli SlyD is a metal ion-regulated peptidyl-prolyl cis/trans-isomerase

In Escherichia coli as many as nine different genes coding for proteins with significant homology to peptidyl-prolyl cis/trans-isomerases (PPIases) have been found. However, for three of them, the histidine-rich SlyD, the homologous gene product of ORF149, and parvulin-like SurA, it was not known whether these proteins really possess PPIase activity. To gain access to the full set of PPIases in E. coli, SlyD, the N-terminal fragment of SlyD devoid of the histidine-rich region, as well as the protein product of ORF149 of E. coli named SlpA (SlyD-like protein) were cloned, overexpressed, and purified to apparent homogeneity. On the basis of the amino acid sequences, both proteins proved to be of the FK506-binding protein type of PPIases. Only when using trypsin instead of chymotrypsin as helper enzyme in the PPIase assay, the enzymatic activity of full-length SlyD and its N-terminal fragment can be measured. For Suc-Ala-Phe-Pro-Arg-4-nitroanilide as substrate, kcat/Km of 29,600 M-1 s-1 for SlyD and 18,600 M-1 s-1 for the N-terminal fragment were obtained. Surprisingly, the PPIase activity of SlyD is reversibly regulated by binding of three Ni2+ ions to the histidine-rich, C-terminal region. Because the PPIase activity of SlpA could be established as well, we now know eight distinct PPIases with proven enzyme activity in E. coli.