Real-time Continuous Measurement of Lactate through a Minimally-invasive Microneedle Biosensor: a Phase I Clinical Study

IntroductionDetermination of blood lactate levels supports decision-making in a range of medical conditions. Invasive blood-sampling and laboratory access are often required, and measurements provide a static profile at each instance. We conducted a Phase I clinical study validating performance of a microneedle patch for minimally-invasive, continuous lactate measurement in healthy volunteers.MethodsFive healthy adult participants wore a solid microneedle biosensor on their forearms and undertook aerobic exercise for 30 minutes. The microneedle biosensor quantifies lactate concentrations in interstitial fluid (ISF) within the dermis continuously and in real-time. Outputs were captured as sensor current and compared with lactate concentrations from venous blood and microdialysis.ResultsThe biosensor was well-tolerated. Participants generated a median peak venous lactate of 9.25 mmol/L (Interquartile range, 6.73 to 10.71). Microdialysate concentrations of lactate closely correlated with blood. Microneedle biosensor current followed venous lactate concentrations and dynamics, with good agreement seen in all participants. There was an estimated lag-time of 5 minutes (IQR -4 to 11 minutes) between microneedle and blood lactate measurements.ConclusionThis study provides first-in-human data on use of a minimally-invasive microneedle biosensor for continuous lactate measurement, providing dynamic monitoring. The platform offers distinct advantages to frequent blood sampling in a wide range of clinical settings, especially where access to laboratory services is limited or blood sampling is infeasible.

Martial Arts Routine Training Method Based on Artificial Intelligence and Big Data of Lactate Measurement

As a traditional Chinese sport, competitive martial arts routines have a long history. The competition rules are the unified norms and standards formulated for sports competitions. They are a yardstick for referees to judge the technical level and competitive ability of athletes and an essential basis for coaches during training. In particular, the new rules increase the difficulty of martial arts routines training and score, improve the balance movement of various groups, highlight the action specifications, increase the proportion of the score, and strengthen the scoring measures for the performance level. Subsequently, this puts higher requirements for the exceptional technical level of routine athletes. Therefore, it is vital to formulate scientific martial arts systematic training methods. This paper considers the above problem and current popular artificial intelligence technology and constructs a neural network algorithm to solve it. In addition, since lactic acid is a good monitoring indicator of the training load intensity and effect of martial arts routine exercises, this article also considers extensive lactate measurement data to construct martial arts systematic training methods. Through simulations, our experimental verification and the obtained results demonstrate the effectiveness of the proposed algorithm.

Process and outcome of management for orthopedic patients with sepsis

Objectives To analyze the management process and outcomes of orthopedic patients diagnosed with sepsis. Methods This retrospective descriptive study included the medical records 275 orthopedics patients with sepsis from January 2017 to December 2019. Data collection was done using the Management Situation for Orthopedic Patients with Sepsis Record Form. Descriptive statistics were used for data analysis. Results Within 3 hours after being diagnosed with sepsis, the following management process occurred: 82.90% of the samples had blood collected for culturing before antibiotic administration, 31.27% received broad-spectrum antibiotics, 15.63% had serum lactate measurement and the 50.00% of the patients requiring fluid resuscitation (n=56) received initial fluid resuscitation. Within 6 hours following diagnosis, the 32.07% of the sample requiring vasopressors (n=53) received them. Of the patients in the study, 13.18% developed septic shock and the overall mortality rate was 18.19% (n=50). Conclusions There are opportunities for improvement of the management process for orthopedic patients with sepsis. Improvements in the quality of the management process could lead to better outcomes.

AUDIT OF SEPSIS IN AN INDIAN TERTIARY CARE CENTRE

Our audit titled audit of sepsis in an Indian tertiary care Center was conducted to assess the percentage of patients in whom the SEPSIS 1 HOUR BUNDLE was followed in our emergency and the steps taken to improve it in our hospital. The study was conducted in a tertiary care center Peerless Hospital and B.K.Roy research center, Kolkata, India. The sample size for the audit is 132. The study was conducted over a period of 1year . As per the Surviving Sepsis guidelines 2017, it was said that the initial resuscitation for sepsis should begin within 1 hour of recognition of sepsis, to decrease the mortality. The components of surviving sepsis bundle is IV crystalloid infusion, blood cultures, IV antibiotics, lactate measurement and early initiation of vasopressors to maintain MAP >65mmHg. From the above study period of 1 year, 67% of the patients were above 60 years and 33% of the patients were below 60 years of age. With this guideline reference, in our audit, we found that 66% of patients received IV crystalloids within 1 hour, in 23% of patients lactate was measured within 1 hour of recognition, blood cultures were taken within 1 hour in 49% of patients, 46% of patients received antibiotics within 1 hour. The lack of awareness regarding the importance of lactate clearance has led to delay in lactate measurement and only 23% of patients had lactate measured within 1 hour. All Emergency departments should have a sepsis lead and a sepsis protocol. Education and training about the importance of 1 hour bundle should be done for wider team for early recognition and instigation of optimal care.

Effect of Timely Lactate Measurement on In-hospital Mortality among Adults with Hypotension and Hyperlactatemia: An Observational Study on Two Cohorts

Background: Whether patients presented with hypotension and hyperlactatemia can benefit from timely lactate measurement and further lactate-guide resuscitation were not fully understood.Methods: This was a retrospective observational study based on the data from the Medical Information Mart for Intensive Care (MIMIC)-III Database and the eICU Collaborative Research Database (eICU). Patients with hypotension (defined as a minimal systolic blood pressure ≤90 mm Hg or minimal mean arterial pressure ≤65 mm Hg or requiring any vasopressors support during the first 24 h after ICU admission) and hyperlactatemia (defined as an initial lactate level > 2.0 mmol/L after ICU admission) were eligible.The primary exposure was the timely lactate measurement, which was defined as an initial lactate level measured within 1 h after ICU admission. The primary outcome was in-hospital mortality. The statistical approaches included multivariate regression, propensity score matching (PSM) and an inverse probability of treatment weighing (IPTW) and causal mediation analysis (CMA) were utilized to elucidate the relationship between timely lactate measurement and in-hospital mortality. Results: A total of 9978 patients were identified, of which 4257 in MIMIC-III and 5721 in eICU. Timely lactate measurement was associated with lower risk-adjusted in-hospital mortality both in MIMIC (OR 0.70 (95%CI 0.58-0.85; p<0.001)) and eICU (OR 0.75 (95%CI 0.64-0.88; p<0.001)). Time to initial intravenous fluid (IVF) in MIMIC mediated 6.7% (95%CI 1.4%-38%; p<0.001) of the beneficial effect of timely lactate measurement (p<0.001 for average causal mediation effect (ACME)) in terms of in-hospital mortality. Finally, delayed initial lactate measurements are also associated an increased in-hospital mortality in MIMIC and eICU.Conclusions: Timely lactate measurement is associated with a lower risk-adjusted in-hospital mortality among patients with hypotension and hyperlactatemia, which was proportional mediated through shortening the time to IVF. Delay in initial lactate measurement showed a positive association with in-hospital mortality.

Investigations into the Effects of pH on Quantitative Measurements of Lactate in Biological Media Using ATR-FTIR Spectroscopy

Quantification of lactate/lactic acid in critical care environments is essential as lactate serves as an important biochemical marker for the adequacy of the haemodynamic circulation in shock and of cell respiration at the onset of sepsis/septic shock. Hence, in this study, ATR-FTIR was explored as a potential tool for lactate measurement, as the current techniques depend on sample preparation and fails to provide rapid response. Moreover, the effects of pH on PBS samples (7.4, 7, 6.5 and 6) and change in solution conditions (PBS to whole blood) on spectral features were also investigated. A total 189 spectra from five sets of lactate containing media were obtained. Results suggests that lactate could be measured with more than 90% accuracy in the wavenumber range of 1500–600 cm−1. The findings of this study further suggest that there exist no effects of change in pH or media, when estimating lactate concentration changes in this range of the Mid-IR spectral region.

Time to Lactate Measurement Affects Efficacy of Initial Lactate on Mortality in critically ill patients with sepsis.

Background: Evidence regarding the effect of time to lactate measurement on the relationship between the initial lactate level and mortality is limited. We aimed to investigate the relationships between time to lactate measurement, initial lactate level, and in-hospital mortality in critically ill patients with sepsis.Methods and Results: Of the 14339 eligible adult patients with recognized sepsis upon admission to the ICU based on the MIMIC-III database, the median value of initial lactate was 1.70 mmol/L (interquartile range [IQR] 1.20-2.80), and its detection time was 3.50 hours ([IQR] 1.31-10.24). The results of fully adjusted multivariate analyses demonstrated that lactate was positively associated with in-hospital mortality (odds ratio: 1.126, 95% confidence interval: 1.090 to 1.163, P<0.001), and there was an increase in the odds of death with hourly delays in lactate measurement (OR: 1.006, 95% CI: 1.004 to 1.008, P<0.001). In stratified analyses, delays in lactate measurement significantly interfered with the impact of increased lactate level on mortality (P-value for interaction<0.001). The hospital mortality rate substantially increased by 43.5% for each unit increase in lactate when measurement was delayed by 24 hours (OR: 1.435, 95% CI: 1.260 to 1.635, P<0.001).Discussion: The association of initial lactate with in-hospital mortality is likely to vary with delays in detection time (grouping based on the “1-hour bundle”) in critically ill patients with recognized sepsis upon admission to the ICU.