The Lombardy SARS-CoV-2 outbreak in February 2020 represented the beginning of COVID-19 epidemic in Italy. Hospitals were flooded by thousands of patients with bilateral pneumonia and severe respiratory, and vital sign derangements compared to the standard hospital population. We propose a new visual analysis technique using heat maps to describe the impact of COVID-19 epidemic on vital sign anomalies in hospitalized patients. We conducted an electronic health record study, including all confirmed COVID-19 patients hospitalized from February 21st, 2020 to April 21st, 2020 as cases, and all non-COVID-19 patients hospitalized in the same wards from January 1st, 2018 to December 31st, 2018. All data on temperature, peripheral oxygen saturation, respiratory rate, arterial blood pressure, and heart rate were retrieved. Derangement of vital signs was defined according to predefined thresholds. 470 COVID-19 patients and 9241 controls were included. Cases were older than controls, with a median age of 79 vs 76 years in non survivors (p = < 0.002). Gender was not associated with mortality. Overall mortality in COVID-19 hospitalized patients was 18%, ranging from 1.4% in patients below 65 years to about 30% in patients over 65 years. Heat maps analysis demonstrated that COVID-19 patients had an increased frequency in episodes of compromised respiratory rate, acute desaturation, and fever. COVID-19 epidemic profoundly affected the incidence of severe derangements in vital signs in a large academic hospital. We validated heat maps as a method to analyze the clinical stability of hospitalized patients. This method may help to improve resource allocation according to patient characteristics.

Beta-blockers are well known to reduce myocardial oxygen consumption (MVO2) and improve the prognosis of heart failure (HF) patients. However, its negative chronotropic and inotropic effects limit their use in the acute phase of HF due to the risk of circulatory collapse. In this study, as a first step for a safe β-blocker administration strategy, we aimed to develop and evaluate the feasibility of an automated β-blocker administration system. We developed a system to monitor arterial pressure (AP), left atrial pressure (PLA), right atrial pressure, and cardiac output. Using negative feedback of hemodynamics, the system controls AP and PLA by administering landiolol (an ultra-short-acting β-blocker), dextran, and furosemide. We applied the system for 60 min to 6 mongrel dogs with rapid pacing-induced HF. In all dogs, the system automatically adjusted the doses of the drugs. Mean AP and mean PLA were controlled within the acceptable ranges (AP within 5 mmHg below target; PLA within 2 mmHg above target) more than 95% of the time. Median absolute performance error was small for AP [median (interquartile range), 3.1% (2.2-3.8)] and PLA [3.6% (2.2-5.7)]. The system decreased MVO2 and PLA significantly. We demonstrated the feasibility of an automated β-blocker administration system in a canine model of acute HF. The system controlled AP and PLA to avoid circulatory collapse, and reduced MVO2 significantly. As the system can help the management of patients with HF, further validations in larger samples and development for clinical applications are warranted.

To predict the mortality of acute respiratory distress syndrome (ARDS) by using a radial basis function (RBF) artificial neural network (ANN) model. This study included 217 patients who were admitted between June 2013 and November 2019. The RBF ANN model and logistic regression (LR) model were based on twelve factors related to ARDS. Statistical indexes were used to determine the value of the prediction in the two models. The sensitivity, specificity and accuracy of the RBF ANN model to predict mortality were 83.6%, 88.5% and 82.5%, respectively. Significant differences were found between the RBF ANN and LR models (P < 0.05). When the RBF ANN model was used to identify ARDS, the area under the ROC curve was 0.854 ± 0.029. LDH, organ failure, SP-D and PaO2/FiO2 were the most important independent variables. The RBF ANN model was more likely to predict the mortality of ARDS than the LR model. In addition, it can extract informative risk factors for ARDS.

Surgery for hip fractures should be performed within 48 h from patient's admission. However, several factors including chronic antiplatelet therapy could delay operation. Among the totality of patients taking clopidogrel, up to 30% are resistant to the drug and have a normal platelets reactivity. We propose thromboelastography (TEG) with an ADP Platelet Mapping assay kit to assess platelet aggregation, a safe tool that could help to avoid surgery delay in those patients treated with antiplatelet therapy. A patient's blood sample was collected for aggregometry. If MA-ADP and platelets aggregation (%) were within normal values, the patient was fit for immediate surgery with neuraxial anesthesia and ultrasound-guided nerve block. If one of the two parameters or both were deranged, a mortality risk assessment was estimated. In the low risk category, the patients waited till normalization of the parameters, whereas in the high-risk group a general anesthesia and peripheral antalgic block was carried out. Nine patients were enrolled. Four of them showed normal aggregometry and surgery was performed within 24 h from admission. Two patients were classified as high mortality risk and surgery was carried out under general anesthesia. Three patients awaited operation till normalization of parameters. No peri or post-operative complications were reported. An aggregometry-guided protocol can safely expedite hip fracture surgery in patients taking clopidogrel. Nonetheless, in presence of a normal platelets function, clinician can opt for a neuraxial instead of general anesthesia reducing the incidence of postoperative delirium and cognitive dysfunction.Trial registration: prospectively registered at clinicaltrials.gov (NCT04642209; date of registration: 23rd November 2020).

Lung ultrasound is a well-established diagnostic tool in acute respiratory failure, and it has been shown to be particularly suited for the management of COVID-19-associated respiratory failure. We present exploratory analyses on the diagnostic and prognostic performance of lung ultrasound score (LUS) in general ward patients with moderate-to-severe COVID-19 pneumonia receiving O2 supplementation and/or noninvasive ventilation. From March 10 through May 1, 2020, 103 lung ultrasound exams were performed by our Forward Intensive Care Team (FICT) on 26 patients (18 males and 8 females), aged 62 (54 - 76) and with a Body Mass Index (BMI) of 30.9 (28.7 - 31.5), a median 6 (5 - 9) days after admission to the COVID-19 medical unit of the University Hospital of Parma, Italy. All patients underwent chest computed tomography (CT) the day of admission. The initial LUS was 16 (11 - 21), which did not significantly correlate with initial CT scans, probably due to rapid progression of the disease and time between CT scan on admission and first FICT evaluation; conversely, LUS was significantly correlated with PaO2/FiO2 ratio throughout patient follow-up [R = - 4.82 (- 6.84 to - 2.80; p < 0.001)]. The area under the receiving operating characteristics curve of LUS for the diagnosis of moderate-severe disease (PaO2/FiO2 ratio ≤ 200 mmHg) was 0.73, with an optimal cutoff value of 11 (positive predictive value: 0.98; negative predictive value: 0.29). Patients who eventually needed invasive ventilation and/or died during admission had significantly higher LUS throughout their stay.

To compare whether the diagnostic evaluation of metabolic acidosis can be improved by using a modified Story method compared to the traditional evaluation in a population of critically ill patients with shock. This prospective cohort study included shock patients admitted to the ICU of a tertiary hospital in Brazil between May 2018 and November 2019. We collected laboratory data necessary for traditional evaluation and the simplified Stewart's method. During the study period, 149 patients were included in the final analysis. Of the 17 patients with a normal SBE and AGcorrected, 13 (76.5%) presented with metabolic acidosis according to the modified Story assessment. Therefore, of the 149 patients included in the study, the traditional approach failed to identify metabolic acidosis that was identified by the modified Story assessment in 13 (8.7%) patients. In addition, the determination of the severity of metabolic acidosis also differed between the two methods by a mean of - 7.8 mEq/L. We found that a modified Story method can identify and quantify metabolic acidosis in patients with disorders that were not revealed by the traditional approach.

This study determined the accuracy and validity for the haemodynamic parameters of haemodynamically stable neonates after postnatal circulatory adaptation using the ultrasonic cardiac output monitor (USCOM) in comparison with echocardiography. We conducted a prospective, observational study of neonates born at 23-41 weeks of gestation. They all underwent both echocardiography and USCOM assessments for comparison purposes. The 127 neonates were examined at the median of postmenstrual age of 35 weeks and there was a very high correlation between the cardiac output measurements provided by both methods. The mean difference in cardiac output was - 12 ± 25 ml/kg/min, with percentage error of 8.3 ± 6.9%. A larger bias was observed in cases with higher left ventricular output. Bland-Altman analysis confirmed no significant bias, with acceptable limits of agreement between these two methods. There was a very good correlation between the USCOM and echocardiographic methods when we used them to measure cardiac output in neonates.

The use of clinical scoring to assess for severity of respiratory distress and respiratory failure is challenging due to subjectivity and interrater variability. Transcutaneous Capnography (TcpCO2) can be used as an objective tool to assess a patient's ventilatory status. This study was designed to assess for any correlation of continuous monitoring of TcpCO2 with the respiratory clinical scores and deterioration in children admitted for acute respiratory distress. A prospective observational study over one year on children aged 2 weeks to 5 years admitted with acute respiratory distress or failure secondary to Bronchiolitis and Reactive airway disease was performed. Continuous TcpCO2 monitoring for upto 48 h was recorded. Investigators, bedside physicians, respiratory therapists, and nurses were blinded from the transcutaneous trends at the time of data collection. Total of 813 TcpCO2 measurements at standard intervals of 30 min were obtained on 38 subjects. Subjects with abnormal TcpCO2 (> 45 mmHg) were younger (6.9 ± 5.2 vs. 23.05 ± 17.7 months,) and were more likely to be on higher oxygen flow rate (0.52 L/min/kg vs 0.46 lier/min/kg, p = 0.004) and higher FiO2 (38.4 vs 33.6, p < 0.001 using heated high flow nasal cannula. No difference was found in bronchiolitis score or PEW score in subjects with normal and abnormal TcpCO2. A small but statistically significant increase in TcpCO2 was observed at the escalation of care. Even though odds of escalation of care are higher with abnormal TcpCO2 (OR 1.92), this difference did not reach statistical significance. pCO2 can provide additive information for non-invasive clinical monitoring of children requiring varying respiratory support; however, it does not provide predictive value for escalation or de-escalation of care.

In this work it is proposed a modeling for operating room times based on a Bayesian Hierarchical structure. Specifically, it is employed a Bayesian generalized linear mixed model with an additional hierarchical level on the random effects. This configuration allows the estimation of operating room times (ORT) with few or no historical observations, without requiring a prior surgeon's estimate. In addition to the widely used lognormal distribution, it is also studied the gamma distribution to model the operating room times. For the scale parameters related to the random effects (surgeon and surgical group), which are important quantities in this type of modeling, different kinds of prior distributions such as Half-Cauchy, Sbeta2, and uniform are studied. A Bayesian version of the classical ANOVA is implemented to identify relevant predictors for the operating room times. We find that lognormal models outperform the gamma models in estimating upper prediction bounds (UB). Especially, the best ORT predictions for cases with few or no historical data (i.e., between 0 and 3 historical cases) are obtained with the [Formula: see text], SBeta2 model. With a deviation of less than 1% with respect to the nominal coverage of the upper bound predictions UB80% and UB90% and an average absolute percentage error of 38.5% in the point estimate.

Postoperative pain in children is usually undertreated because of their inability to complain. While several pain assessment scales have been developed, they have shortcomings such as subjectivity and being observer-dependent. This study aimed to assess the validity of the perfusion index as an objective measure of postoperative pain in children undergoing adenotonsillectomy. Children aged 3-7 years were enrolled. The Children's Hospital of Eastern Ontario Scale (CHEOPS) was used to assess postoperative pain. The perfusion index was measured at the same time intervals as CHEOPS. The highest CHEOPS before rescue analgesia was administered and CHEOPS when the patients became pain-free were recorded with the corresponding perfusion index. The primary outcome was the correlation between the postoperative CHEOPS and the corresponding postoperative perfusion index. The secondary outcomes were the ability of perfusion index changes to predict the presence of postoperative pain and patients' response to analgesics. The postoperative perfusion index was negatively correlated with CHEOPS at 30 and 90 min postoperatively. The change in the preoperative baseline perfusion index (ΔPI-pre) was moderately correlated with the highest CHEOPS (CHEOPS-1) (r = 0.61, p = 0.001). The change in the postoperative perfusion index (ΔPI-po) was negatively correlated with the change in the CHEOPS (ΔCHEOPS) (r = - 0.53, P = 0.0001). The ΔPI-pre was an excellent predictor of postoperative pain (AUROC 0.83 with 71% sensitivity, 83% specificity, and a cut-off value of ≥ 0.26). The perfusion index is a good objective measure for predicting the presence of postoperative pain in children undergoing adenotonsillectomy under general anesthesia. Trial registration: ClinicalTrials.gov; ID: (NCT03854604) registered on February 2019.

Tidal volume monitoring may help minimize lung injury during respiratory assistance. Surface imaging using time-of-flight camera is a new, non-invasive, non-contact, radiation-free, and easy-to-use technique that enables tidal volume and respiratory rate measurements. The objectives of the study were to determine the accuracy of Time-of-Flight volume (VTTOF) and respiratory rate (RRTOF) measurements at the bedside, and to validate its application for spontaneously breathing patients under high flow nasal canula. Data analysis was performed within the ReaSTOC data-warehousing project (ClinicalTrials.gov identifier NCT02893462). All data were recorded using standard monitoring devices, and the computerized medical file. Time-of-flight technique used a Kinect V2 (Microsoft, Redmond, WA, USA) to acquire the distance information, based on measuring the phase delay between the emitted light-wave and received backscattered signals. 44 patients (32 under mechanical ventilation; 12 under high-flow nasal canula) were recorded. High correlation (r = 0.84; p < 0.001), with low bias (-1.7 mL) and acceptable deviation (75 mL) was observed between VTTOF and VTREF under ventilation. Similar performance was observed for respiratory rate (r = 0.91; p < 0.001; bias < 1b/min; deviation ≤ 5b/min). Measurements were possible for all patients under high-flow nasal canula, detecting overdistension in 4 patients (tidal volume > 8 mL/kg) and low ventilation in 6 patients (tidal volume < 6 mL/kg). Tidal volume monitoring using time-of-flight camera (VTTOF) is correlated to reference values. Time-of-flight camera enables continuous and non-contact respiratory monitoring under high-flow nasal canula, and enables to detect tidal volume and respiratory rate changes, while modifying flow. It enables respiratory monitoring for spontaneously patients, especially while using high-flow nasal oxygenation.

This study aimed to evaluate the relationship between ultrasonographic gastric antral measurements and aspirated gastric residual volume (GRV) in mechanically ventilated critically ill patients receiving enteral nutrition (EN). This prospective observational study included 56 enterally-fed critically ill patients in one-year period. All imaging procedures were done at 30-degree head-of-bed elevation and supine position on epigastric region of abdomen with 2.5-6 MHz convex-array probe just before routine GRV aspiration. The antral cross-sectional area (CSA) was calculated by measuring the anteroposterior (dAP) and craniocaudal diameters (dCC) of the gastric antrum. Total 283 ultrasonographic gastric antrum imaging procedures were done. In only eight (2.82%) attempts, the antrum could not be visualized due to inhibition from intra-gastric air or gas in the surrounding intestinal lumen. The calculated mean antral CSA was 568.15 ± 348.37 mm2 (103.43-2,846.30). The antral CSA correlated significantly with aspirated GRV, and the antral CSA increased linearly with increasing aspirated GRV (R2 = 0.73, p < 0.0001). In Receiver operating characteristic (ROC) analysis of antral CSA ≥ 920 mm2 (mean + 1*SD) for estimating aspirated GRV, the area under the curve (AUC) was 0.848 (95% CI, 0.76 ~ 0.93) (p < 0.0001), and ROC analysis of antral CSA to discriminate aspirated GRV ≥ 250 mL showed a significant relation (AUC = 0.969, 95% CI 0.94 ~ 0.99, p < 0.0001). Ultrasonographic measurement of gastric antral CSA is an easy and reliable bedside procedure to estimate GRV in critically ill patients receiving EN in 30-degree head-of-bed elevation and supine position. Trial registration number: NCT04413474, date of registration: June 17, 2020, retrospectively registered.

Patients undergoing coronary artery bypass grafting (CABG) are at risk of developing postoperative renal impairment, amongst others caused by renal ischemia and hypoxia. Intra-operative monitoring of renal region tissue oxygenation (SrtO2) might be a useful tool to detect renal hypoxia and predict postoperative renal impairment. Therefore, the aim of this study was to assess the ability of intra-operative SrtO2 to predict postoperative renal impairment, defined as an increase of serum creatinine concentrations of > 10% from individual baseline, and compare this with the predictive abilities of peripheral and cerebral tissue oxygenation (SptO2 and SctO2, respectively) and renal specific tissue deoxygenation. Forty-one patients undergoing elective CABG were included. Near-infrared spectroscopy (NIRS) was used to measure renal region, peripheral (thenar muscle) and cerebral tissue oxygenation during surgery. Renal region specific tissue deoxygenation was defined as a proportionally larger decrease in SrtO2 than SptO2. ROC analyses were used to compare predictive abilities. We did not observe an association between tissue oxygenation measured in the renal region and cerebral oxygenation and postoperative renal impairment in this small retrospective study. In contrast, SptO2 decrease > 10% from baseline was a reasonable predictor with an AUROC of 0.767 (95%CI 0.619 to 0.14; p = 0.010). Tissue oxygenation of the renal region, although non-invasively and continuously available, cannot be used in adults to predict postoperative renal impairment after CABG. Instead, peripheral tissue deoxygenation was able to predict postoperative renal impairment, suggesting that SptO2 provides a better indication of 'general' tissue oxygenation status.Registered at ClinicalTrials.gov: NCT01347827, first submitted April 27, 2011.

Almost since its introduction pulse oximetry was known to overestimate oxygen saturation in cases of carbon monoxide poisoning or elevated methemoglobin (metHb) levels. To eliminate this dangerous behavior some manufacturers have added additional LED emitters to try to increase the number of measured hemoglobin species and to improve measurement accuracy, but have not been very successful. We hypothesized that the use of narrow-band laser light sources would make accurate and precise measurement of the four primary species of hemoglobin possible, even in cases of elevated levels of carboxyhemoglobin (COHb). Calibration and verification studies were performed on a tissue simulator that employed an artificial finger pulsating with whole human blood. This simulator allowed safe generation of 165 different combinations of the levels of oxyhemoglobin (O2Hb), COHb, metHb, and reduced hemoglobin (RHb) for calibration of the laser-based pulse oximeter. A follow-on study used 56 mixed hemoglobin levels for verification and statistical analysis of the performance of this device. This laser-based pulse oximeter measured all four species of hemoglobin accurately and precisely (ARMS ≤ 1.8%) for metHb levels in the clinically normal range. At elevated metHb levels the device continued to provide accurate and precise measurements of metHb and RHb (ARMS ≤ 1.7%). The use of monochromatic laser light sources can create a new generation of highly accurate, multi-parameter, pulse oximeters.

Augmented reality (AR) is the integration of computer-generated information with the user's environment in real time. AR is used in many industries, including healthcare, where it has gained significant popularity. Recent strides in hardware and software engineering have reduced the cost of AR, while significantly improving the experience for users and developers. One of the first applications of AR technology in perioperative medicine has been in the identification of anatomical structures for regional blocks and peripheral or central vascular access. AR has also been implemented in pediatric care to reduce periprocedural anxiety. In this narrative review, we summarize the current role of AR in anesthesiology, pain medicine, and critical care.

The BIS and Entropy systems are used as indicators of anaesthetic drug effect, and can also record EEGs in digital form. A number of studies have used such recordings for analysis, even though information about bandwidth and fidelity has not been provided by the manufacturers. In this study we consider these systems purely as EEG recording devices, and evaluate their suitability for quantitative analysis. Using a calibrated electronic testing system, we played an artificial test signal of known amplitude with frequency varying from 0.01 to 400 Hz into the BIS and Entropy EEG systems, and saved the recording in each of their supported recording modes. The amplitude of the recording at each frequency was then used to derive the frequency response curves, as well as the 3 dB and 0.5 dB points for each mode. There are important differences between the various BIS and Entropy recordings. The BIS 256 Hz and the Entropy 400 Hz recordings are broadly comparable, although Entropy has a slightly reduced response above 50 Hz and below 1 Hz. The BIS 128 Hz recording has a somewhat reduced bandwidth, due to its relatively low sampling rate. The Entropy 100 Hz recording in the Datex-Ohmeda S/5 monitor has a flawed implementation, leading to aliasing of signals over 50 Hz and potential distortion of the recording, while in the GE Carescape it has an uneven response and a narrowed bandwidth. Consequently, it is important to know which specific host monitor was used when an Entropy 100 Hz recording was made. In summary, the choice of recording device and host monitor may affect the results of some quantitative EEG analysis, and some previously published studies may need to be re-evaluated.

Most established severity-of-illness systems used for prediction of intensive care unit (ICU) mortality were developed targeted at the general ICU population, based on logistic regression (LR). To date, no dynamic predictive tool for ICU mortality has been developed targeted at the Cardiac Surgery Recovery Unit (CSRU) and Coronary Care Unit (CCU) using machine learning (ML). CSRU and CCU adult patients from the MIMIC-III critical care database were studied. The ML methods developed extract ICU data during a 5-h window and demographic features to produce mortality predictions and were compared to six established severity-of-illness systems and LR. In a secondary experiment, additional procedure/surgery and ICU features were added to the models. The ML models developed were the Tree Ensemble (TE), Random Forest, XGBoost Tree Ensemble (XGB), Naive Bayes (NB), and Bayesian network. The discrimination, calibration and accuracy statistics were assessed. The AUROC values were superior for the ML models reaching 0.926 and 0.924 for the XGB, and 0.904 and 0.908 for the TE for ICU mortality prediction in the primary and secondary experiments respectively. Among the conventional systems, the serial SOFA obtained the highest AUROC (0.8405). The Brier score was better for the ML models except the NB over the conventional systems. The accuracy statistics less sensitive to unbalanced cohorts were higher for all the ML models. In conclusion, the predictive power of XGB was excellent, substantially outperforming the conventional systems and LR. The ML models developed in this work offer promising results that could benefit CSRU and CCU.

Cerebral blood flow is tightly regulated by cerebrovascular autoregulation (CVA), and intraoperative impairment of CVA has been linked with perioperative neurocognitive disorders. We aim to assess whether impairment of CVA during major oncologic surgery is associated with delayed neurocognitive recovery (DNCR) postoperatively. We performed a secondary analysis of prospectively collected data. Patients were included if they had undergone complete pre- and postoperative neuropsychological assessments, continuous intraoperative measurement of CVA, and major oncologic surgery for visceral, urological, or gynecological cancer. Intraoperative CVA was measured using the time-correlation method based on near-infrared-spectroscopy, and DNCR was assessed with a neuropsychological test battery. A decline in cognitive function before hospital discharge compared with a preoperative baseline assessment was defined as DNCR. One hundred ninety-five patients were included in the analysis. The median age of the study population was 65 years (IQR: 60-68); 11 patients (5.6%) were female. Forty-one patients (21.0%) fulfilled the criteria for DNCR in the early postoperative period. We found a significant association between impaired intraoperative CVA and DNCR before hospital discharge (OR = 1.042 [95% CI: 1.005; 1.080], p = 0.028). The type of surgery (radical prostatectomy vs. other major oncologic surgery; OR = 0.269 [95% CI: 0.099; 0.728], p = 0.010) and premedication with midazolam (OR = 3.360 [95% CI: 1.039; 10.870], p = 0.043) were significantly associated with the occurrence of DNCR in the early postoperative period. Intraoperative impairment of CVA is associated with postoperative neurocognitive function early after oncologic surgery. Therefore, intraoperative monitoring of CVA may be a target for neuroprotective interventions. The initial studies were retrospectively registered with primary clinical trial registries recognized by the World Health Organization (ClinicalTrials.gov Identifiers: DRKS00010014, 21.03.2016 and NCT04101006, 24.07.2019).

We assessed extracranial contamination of the near-infrared spectroscopy (NIRS) signal during administration of phenylephrine. The study was performed with NIRO 200NX which employs both the Modified Beer-Lambert (MBL) method to measure total hemoglobin (tHb, expressed in µM), and Spatially Resolved Spectroscopy (SRS) to measure total hemoglobin content (nTHI, expressed in arbitrary units (a.u.)). SRS tends to not be affected by extracranial blood flow. As vasoconstriction with phenylephrine mainly occurs in the extracranial area, we hypothesized that if NIRS measurements are indeed prone to extracranial contamination, tHb will be more affected by the administration of phenylephrine than nTHI. After ethical committee approval, 20 consenting cardiac surgery patients were included. Phenylephrine was administered whenever clinically indicated and its effect on nTHI and tHb was evaluated. To adjust for the difference in raw scale units, Z-scores were calculated. Data were analyzed with Wilcoxon Signed Ranks Test and the Hodges-Lehmann method. A total of 191 data sets were obtained in 20 patients (10 male, 65 ± 15 years, 77 ± 16 kg, 166 ± 11 cm). The median difference before and after administration of phenylephrine was - 0.006 a.u. [95%CI - 0.010 to - 0.002] (p < 0.001) and - 0.415 µM [95%CI - 0.665 to - 0.205] (p < 0.001) for nTHI and tHb, respectively. The median difference between the Z-scores of nTHI and tHb was - 0.02 [95%CI - 0.04 to - 0.003] (p = 0.03), with a higher variability in the Z-scores of tHb. Phenylephrine induced significant larger changes in MBL values compared to SRS values, indicating that the MBL method might be more prone to extracranial contamination. Trial and clinical registry: Trial registration number: B670201939459, ethical committee number: 2019/0265, date of approval: March 19, 2019.

Lactate levels are commonly used as an indirect measure to assess metabolic stress in clinical conditions like sepsis. Dynamic lactate measurements are recommended to assess and guide treatment in patients with shock and other critical care conditions. A minimally invasive, continuous lactate monitor has potential to improve clinical decisions and patient care. The purpose of the study was to evaluate continuous lactate measurements of a novel enzymatic Continuous Lactate Monitor (CLM) developed in our laboratory. Lactate levels were monitored during incremental cycling exercise challenges as a tool for hyperlactatemia. Six healthy individuals 18-45 y/o (4 males, 2 females) participated in the study. CLM devices were inserted subcutaneously in the postero-lateral trunk below the renal angle, one hour before the exercise challenge. Each exercise challenge consisted of a 3 to 12-min warm up period, followed by up to 7, 4-min incremental workload bouts separated by rest intervals. Continuous lactate measurements obtained from CLM were compared with commercial lactate analyzer (Abbott iSTAT) measurements of venous blood (plasma) drawn from the antecubital vein. Blood was drawn at up to 25 time points spanning the duration of before exercise, during exercise, and up to 120 min post exercise. Area under the curve (AUC), and delay time were calculated to compare the CLM readings with plasma lactate concentration. Average plasma lactate concentration increased from 1.02 to 16.21 mM. Ratio of AUC derived from CLM to plasma lactate was 1.025 (0.990-1.058). Average dynamic delay time of CLM to venous plasma lactate was 5.22 min (2.87-10.35). Insertion sites examined 48 h after CLM removal did not show signs of side effects and none required medical attention upon examination. The newly developed CLM has shown to be a promising tool to continuously measure lactate concentration in a minimally invasive fashion. Results indicate the CLM can provide needed trends in lactate over time. Such a device may be used in the future to improve treatment in clinical conditions such as sepsis.

Little is known about microcirculatory dysfunction following abdominal surgeries. This study aimed to evaluate changes in microvascular reactivity (MVR) before and after major abdominal surgery, assessed by near-infrared spectroscopy in conjunction with a vascular occlusion test. This prospective observational study included 50 adult patients who underwent hepato-pancreato-biliary surgery lasting ≥ 8 h. MVR was assessed by tissue oxygen saturation (StO2) changes in the plantar region of the foot during 3 min of vascular occlusion and subsequent release under general anesthesia before and after surgery. The primary outcome was alteration in the recovery slope of StO2 (RecStO2) and recovery time (tM) between the preoperative and postoperative values. Postoperative short-term outcome was represented by the Post-operative Morbidity Survey (POMS) score on the morning of postoperative day 2. After surgery, RecStO2 was reduced (0.74% [0.58-1.06]/s vs. 0.89% [0.62-1.41]/s, P = 0.001), and tM was longer (57.0 [42.9-71.0] s vs. 41.3 [35.5-56.5] s, P < 0.001), compared to the preoperative values. Macrohemodynamic variables such as cardiac index, arterial pressure, and stroke volume during postoperative measurement did not differ with or without relative MVR decline. In addition, the POMS score was not associated with postoperative alterations in microcirculatory responsiveness. MVR in the plantar region of the foot was reduced after major hepato-pancreato-biliary surgery regardless of macrocirculatory adequacy. Impaired MVR was not associated with short-term outcomes as long as macrocirculatory indices were well maintained. The impact of relative microcirculatory changes, especially combined with inadequate macrocirculation, on postoperative complications remains to be elucidated.Clinical Trial Registrations UMIN-CTR trial ID: 000033461.

Mean systemic filling pressure (Pms) is a promising parameter in determining intravascular fluid status. Pms derived from venous return curves during inspiratory holds with incremental airway pressures (Pms-Insp) estimates Pms reliably but is labor-intensive. A computerized algorithm to calculate Pms (Pmsa) at the bedside has been proposed. In previous studies Pmsa and Pms-Insp correlated well but with considerable bias. This observational study was performed to validate Pmsa with Pms-Insp in cardiac surgery patients. Cardiac output, right atrial pressure and mean arterial pressure were prospectively recorded to calculate Pmsa using a bedside monitor. Pms-Insp was calculated offline after performing inspiratory holds. Intraclass-correlation coefficient (ICC) and assessment of agreement were used to compare Pmsa with Pms-Insp. Bias, coefficient of variance (COV), precision and limits of agreement (LOA) were calculated. Proportional bias was assessed with linear regression. A high degree of inter-method reliability was found between Pmsa and Pms-Insp (ICC 0.89; 95%CI 0.72-0.96, p = 0.01) in 18 patients. Pmsa and Pms-Insp differed not significantly (11.9 mmHg, IQR 9.8-13.4 vs. 12.7 mmHg, IQR 10.5-14.4, p = 0.38). Bias was -0.502 ± 1.90 mmHg (p = 0.277). COV was 4% with LOA -4.22 - 3.22 mmHg without proportional bias. Conversion coefficient Pmsa ➔ Pms-Insp was 0.94. This assessment of agreement demonstrates that the measures Pms-Insp and the computerized Pmsa-algorithm are interchangeable (bias -0.502 ± 1.90 mmHg with conversion coefficient 0.94). The choice of Pmsa is straightforward, it is non-interventional and available continuously at the bedside in contrast to Pms-Insp which is interventional and calculated off-line. Further studies should be performed to determine the place of Pmsa in the circulatory management of critically ill patients. (www.clinicaltrials.gov ; TRN NCT04202432, release date 16-12-2019; retrospectively registered).Clinical Trial Registration www.ClinicalTrials.gov , TRN: NCT04202432, initial release date 16-12-2019 (retrospectively registered).

High-flow nasal oxygen (HFNO) has been used in "tubeless" shared-airway surgeries but whether HFNO increased the fire hazard is yet to be examined. We used a physical model for simulation to explore fire safety through a series of ignition trials. An HFNO device was attached to a 3D-printed nose with nostrils connected to a degutted raw chicken. The HFNO device was set at twenty combinations of different oxygen concentration and gas flow rate. An electrocautery and diode laser were applied separately to a fat cube in the cavity of the chicken. Ten 30 s trials of continuous energy source application were conducted. An additional trial of continuous energy application was conducted if no ignition was observed for all the ten trials. A total of eight short flashes were observed in one hundred electrocautery tests; however, no continuous fire was observed among them. There were thirty-six events of ignition in one hundred trials with laser, twelve of which turned into violent self-sustained fires. The factors found to be related to a significantly increased chance of ignition included laser application, lower gas flow, and higher FiO2. The native tissue and smoke can ignite and turn into violent self-sustained fires under HFNO and continuous laser strikes, even in the absence of combustible materials. The results suggest that airway surgeries must be performed safely with HFNO if only a short intermittent laser is used in low FiO2.

This study aimed to investigate the efficacy of intraoperative motor evoked potential (MEP) and somatosensory evoked potential (SSEP) monitoring for predicting postoperative motor deficits (PMDs) in patients with internal carotid artery (ICA) aneurysms. The data for 138 patients with ICA aneurysms who underwent surgical clipping as well as their intraoperative neuromonitoring data were retrospectively reviewed. The efficacy of MEP/SSEP changes for predicting PMDs was assessed using binary logistic regression analysis. Subsequently, receiver operating characteristic curve analysis was used to obtain a supplementary critical value of the MEP/SSEP deterioration duration. The sensitivity and specificity of MEP changes for predicting PMDs were 0.824 and 0.843, respectively. For SSEP changes, the sensitivity and specificity were 0.529 and 0.959, respectively. MEP and SSEP changes were identified as independent predictors for short-term (p = 0.002 and 0.011, respectively) and long-term PMDs (p = 0.040 and 0.006, respectively). The supplementary critical value for MEP deterioration duration for predicting PMDs was 14 min (p = 0.007, AUC = 0.805). For SSEP, the value was 14.5 min (p = 0.042, AUC = 0.875). The MEP/SSEP changes adjusted by those optimal values were also identified as independent predictors for short-term (p < 0.001 and p = 0.005, respectively) and long-term PMDs (p = 0.019 and 0.003, respectively). Intraoperative MEP and SSEP deterioration durations are effective in predicting PMDs in patients with ICA aneurysms.

The duration of action of extravasated rocuronium varies depending on the patient's comorbidities. In patients who receive high doses of non-depolarizing neuromuscular blocking agents subcutaneously, anesthesiologists should be aware of unexpected prolongation of the progress and recovery of neuromuscular block. In such cases, the depth and recovery of neuromuscular block should be objectively monitored to avoid residual neuromuscular block and recurarization.