PaCO2 Research Articles

Sea surface carbon dioxide during early summer at the Tuandao nearshore time series site

To investigate air-sea CO2 flux at the Qingdao nearshore site and its temporal variations, a high-resolution continuous observation of surface carbon dioxide partial pressure (pCO2) was carried out at Zhongyuan Pier near Tuandao from May 25 to July 8, 2019. It was observed that during this period, surface pCO2 varied between ∼490 and ∼690 μatm, mainly associated with sea surface temperature. Surface pCO2 also displayed substantial diurnal variations, with an average amplitude of 64 ± 21 μatm, largely dominated by biological activities. During the observational period, this site acted as a source of atmospheric CO2, releasing 361 mmol CO2 m−2. The notable diurnal variations in air-sea CO2 flux, such as the observed average amplitude of 10.9 mmol m−2 d−1 in this study, pose a challenge for accurately estimating the air-sea CO2 flux in coastal regions without high-resolution observations.

Improved exercise ventilatory efficiency with nasal compared to oral breathing in cardiac patients.

Objectives: To assess whether nasal breathing improves exercise ventilatory efficiency in patients with heart failure (HF) or chronic coronary syndromes (CCS). Background: Exercise inefficient ventilation predicts disease progression and mortality in patients with cardiovascular diseases. In healthy people, improved ventilatory efficiency with nasal compared to oral breathing was found. Methods: Four study groups were recruited: Patients with HF, patients with CCS, old (age≥45years) and young (age 20-40years) healthy control subjects. After a 3-min warm-up, measurements of 5min with once nasal and once oral breathing were performed in randomized order at 50% peak power on cycle ergometer. Ventilation and gas exchange parameters measured with spiroergometry were analysed by Wilcoxon paired-sample tests and linear mixed models adjusted for sex, height, weight and test order. Results: Groups comprised 15 HF, CCS, and young control and 12 old control. Ventilation/carbon dioxide production ( E/ CO2), ventilation ( E), breathing frequency (fR), and end-tidal oxygen partial pressure (PETO2) were significantly lower and tidal volume and end-tidal carbon dioxide partial pressure (PETCO2) significantly higher during nasal compared to oral breathing in all groups, with large effect sizes for most parameters. For patients with HF, median E/ CO2 was 35% lower, fR 26% lower, and PETCO2 10% higher with nasal compared to oral breathing, respectively. Exercise oscillatory ventilation (EOV) was present in 6 patients and markedly reduced with nasal breathing. Conclusion: Nasal breathing during submaximal exercise significantly improved ventilatory efficiency and abnormal breathing patterns (rapid shallow breathing and EOV) in 80% of our patients with HF and CCS.

Factors Predicting Spontaneous Closure of Patent Ductus Arteriosus in Very Low Birth Weight Neonates.

Background Patent ductus arteriosus (PDA) is a relatively rare condition among neonates in the United States, estimated at approximately 1 in every 2,000 births. Managing hemodynamically significant patent ductus arteriosus (hsPDA) in very low birth weight (VLBW) neonates remains a challenge. This study aims to explore and report on the spontaneous closure of hsPDA in VLBW infants in a clinical setting. Methods We conducted a retrospective review of VLBW infants born from 2006 to 2014 at our institution. Infants included in the study were diagnosed with hsPDA via echocardiogram in the first week of life. We divided our population into two study groups: 1) those with PDA closure before discharge without medical/surgical treatment (spontaneous closure) and 2) those with closure by medical/surgical treatment. Relevant baseline data and PDA-related parameters were extracted from the medical records. Results A total of 108 infants were included in the study; 52 experienced spontaneous PDA closure, and 56 required treatment. Of the baseline characteristics, gestational age and mode of delivery differed significantly between the two groups. Within the adjusted model, cesarean section (CS) (OR: 0.18; 95% CI: 0.06-0.55), average pre-diagnosis partial pressure of carbon dioxide (PCO2) (OR: 0.92; 95% CI: 0.86-0.98), and pre-diagnosis daily fluid intake (OR: 0.96; 95% CI: 0.94-0.99) were associated with increased odds of spontaneous closure. Conclusion In our study of VLBW infants, several variables were associated with spontaneous hsPDA closure. Studies with larger sample sizes are much needed and have the potential to clinically impact the outcomes of neonates living with this relatively rare condition.

Pediatric septic shock estimation using deep learning and electronic medical records.

Diagnosing pediatric septic shock is difficult due to the complex and often impractical traditional criteria, such as systemic inflammatory response syndrome (SIRS), which result in delays and higher risks. This study aims to develop a deep learning-based model using SIRS data for early diagnosis in pediatric septic shock cases. The study analyzed data from pediatric patients (<18 years old) admitted to a tertiary hospital from January 2010 to July 2023. Vital signs, lab tests, and clinical information were collected. Septic shock cases were identified using SIRS criteria and inotrope use. A deep learning model was trained and evaluated using the area under the receiver operating characteristics curve (AUROC) and area under the precision-recall curve (AUPRC). Variable contributions were analyzed using the Shapley additive explanation value. The analysis, involving 9,616,115 measurements, identified 34,696 septic shock cases (0.4%). Oxygen supply was crucial for 41.5% of the control group and 20.8% of the septic shock group. The final model showed strong performance, with an AUROC of 0.927 and AUPRC of 0.879. Key influencers were age, oxygen supply, sex, and partial pressure of carbon dioxide, while body temperature had minimal impact on estimation. The proposed deep learning model simplifies early septic shock diagnosis in pediatric patients, reducing the diagnostic workload. Its high accuracy allows timely treatment, but external validation through prospective studies is needed.

Progress on the Effects of Permissive Hypercapnia on the CNS During the Intraoperative Period: A Narrative Review.

Previous experimental findings and clinical evidence have shown the important role of carbon dioxide (CO2) in regulating cerebral vascular tension. CO2 can affect the CNS through various mechanisms. With factors such as patient physiology or surgical interventions potentially causing increased arterial partial pressure of carbon dioxide (PaCO2) levels during mechanical ventilation in general anesthesia, it is important to explore the potential risks or benefits of intraoperative permissive hypercapnia on brain function. In November 2023, we conducted a thorough review of PubMed to establish the article outline. Articles that were non-English or repetitive were eliminated. We collected information on the year, topic, key findings, and opinions of each article. This review not only comprehensively summarizes the factors that contribute to the elevation of intraoperative PaCO2, but also explores the impact of fluctuations in PaCO2 levels on the CNS and the underlying mechanisms involved. At the same time, this article provides our understanding of the potential clinical significance of actively regulating PaCO2 levels. In addition, we propose that the aspects of permissive hypercapnia can be further studied to provide a reliable basis for clinical decision-making. The effects of permissive hypercapnia on the CNS remain a topic of debate. Further prospective randomized controlled studies are needed to determine if permissive hypercapnia can be safely promoted during mechanical ventilation in general anesthesia.

A predictive model for 28-day mortality after discharge in patients with sepsis associated with cerebrovascular disease.

The present study investigated the association between cerebrovascular diseases and sepsis, including its occurrence, progression, and impact on mortality. However, there is currently a lack of predictive models for 28-day mortality in patients with cerebrovascular disease associated with sepsis. The objective of this study is to examine the mortality rate within 28 days after discharge in this population, while concurrently developing a corresponding predictive model. The data for this retrospective cohort study were obtained from the MIMIC-IV database. Patients with sepsis and cerebrovascular disease in the ICU were included. Laboratory indicators, vital signs, and demographic data were collected within 24 hours of ICU admission. Mortality rates within 28 days after discharge were calculated based on patient death times. Logistic regression analysis was used to identify potential variables for a predictive model. A nomogram visualized the prediction model. The performance of the model was evaluated using ROC curves, Calibration plots, and DCA. The study enrolled a total of 2660 patients diagnosed with cerebrovascular disease complicated by sepsis, consisting of 1434 males (53.91%) with a median age of 70.97 (59.60, 80.73). Among this cohort of patients, a total of 751 fatalities occurred within 28 days following discharge. The multivariate regression analysis revealed that age, creatinine, arterial oxygen partial pressure (Pa O2), arterial carbon dioxide partial pressure (Pa CO2), respiratory rate, white blood cell (WBC) count, Body Mass Index (BMI), and race demonstrated potential predictive variables. The aforementioned model yielded an area under the ROC curve of 0.744, accompanied by a sensitivity of 66.2% and specificity of 71.2%. Furthermore, both calibration plots and DCA demonstrated robust performance in practical applications. The proposed prediction model allows clinicians to promptly assess the mortality risk in patients with cerebrovascular disease complicated by sepsis within 28 days after discharge, facilitating early intervention strategies. Consequently, clinicians can implement additional advantageous medical interventions for individuals with cerebrovascular disease and sepsis.

Severe Spaceflight-Associated Neuro-Ocular Syndrome in an Astronaut With 2 Predisposing Factors

Understanding potential predisposing factors associated with spaceflight-associated neuro-ocular syndrome (SANS) may influence its management. To describe a severe case of SANS associated with 2 potentially predisposing factors. Ocular testing of and blood collections from a female astronaut were completed preflight, inflight, and postflight in the setting of the International Space Station (ISS). Weightlessness throughout an approximately 6-month ISS mission. Mean carbon dioxide (CO2) partial pressure decreased from 2.6 to 1.3 mm Hg weeks before the astronaut's flight day (FD) 154 optical coherence tomography (OCT) session. In response to SANS, 4 B-vitamin supplements (vitamin B6, 100 mg; L-methylfolate, 5 mg; vitamin B12, 1000 μg; and riboflavin, 400 mg) were deployed, unpacked on FD153, consumed daily through FD169, and then discontinued due to gastrointestinal discomfort. Refraction, distance visual acuity (DVA), optic nerve, and macular assessment on OCT. Cycloplegic refraction was -1.00 diopter in both eyes preflight and +0.50 - 0.25 × 015 in the right eye and +1.00 diopter in the left eye 3 days postflight. Uncorrected DVA was 20/30 OU preflight, 20/16 or better by FD90, and 20/15 OU 3 days postflight. Inflight peripapillary total retinal thickness (TRT) peaked between FD84 and FD126 (right eye, 401 μm preflight, 613 μm on FD84; left eye, 404 μm preflight, 636 μm on FD126), then decreased. Peripapillary choroidal folds, quantified by surface roughness, peaked at 12.7 μm in the right eye on FD154 and 15.0 μm in the left eye on FD126, then decreased. Mean choroidal thickness increased throughout the mission. Genetic analyses revealed 2 minor alleles for MTRR 66 and 2 major alleles for SHMT1 1420 (ie, 4 of 4 SANS risk alleles). One-week postflight, lumbar puncture opening pressure was normal, at 19.4 cm H2O. To the authors' knowledge, no other report of SANS documented as large of a change in peripapillary TRT or hyperopic shift during a mission as in this astronaut, and this was only 1 of 4 astronauts to experience chorioretinal folds approaching the fovea. This case showed substantial inflight improvement greater than the sensitivity of the measure, possibly associated with B-vitamin supplementation and/or reduction in cabin CO2. However, as a single report, such improvement could be coincidental to these interventions, warranting further evaluation.

Reference limits for blood gas analysis performed from coccygeal vessels of multiparous Holstein dairy cows: Effects of stage of lactation and season of sampling

Blood gas analysis is a great support to the diagnostic process of critically ill patients. Its correct application to the medicine of dairy cows depends on the availability of specific reference intervals that are still difficult to find in the literature. They may vary according to the type of blood sampled, animals' age and production stage, and climatic conditions. This study aimed at calculating the reference limits for some blood gas parameters in the blood collected from the coccygeal vessels of multiparous Holstein dairy cows. This site of sampling implies the risk of withdrawing blood of unknown origin (venous, arterial, or mixed), but has a high practical interest for the easy and quick performance and the minimal animal restraint required. Data from 379 cows were used, and reference limits were produced for pH, partial pressure of carbon dioxide (pCO2), bicarbonate concentration (HCO3), total carbon dioxide concentration (tCO2), oxygen saturation (sO2), hemoglobin (Hb), hematocrit (Hct), base excess (BE), glucose, Na, K, and ionized calcium (iCa). The effects of stage of lactation (5 to 60 vs. > 60 DIM) and season of sampling (cold vs. hot) were investigated, and specific reference limits were produced for each variable and each level of the factors whenever a significant effect was detected. The pH, sO2, K, and iCa were not influenced by season or stage of lactation. All the other blood gas parameters were significantly affected by season of sampling, and Hb, Hct, glucose, and Na were also affected by stage of lactation. Reference limits provided in this study are specific to the site of sampling (coccygeal vessels) and the animal category considered. Further studies are needed to produce reference intervals for other blood gas parameters, cow categories, and blood types.

Estimating of end-tidal carbon dioxide partial pressure in patients with cardiovascular diseases at rest and during physical activity: minireview

Estimating of end-tidal carbon dioxide partial pressure in patients with cardiovascular diseases at rest and during physical activity: minireview

Kinetic analysis of reversible solid-gas reactions in films: application to the decomposition of CaCO$$_3$$ and BaCO$$_3$$ carbonates

AbstractTo determine the decomposition conditions of carbonates in the form of films, we investigated the dependence of the kinetics on carbon dioxide partial pressure, temperature and film thickness. Three different analyses allow us to determine the functional dependence of the decomposition onset temperature on the CO$$_2$$ 2 partial pressure, of the reaction rate on the temperature and of the kinetics on the film thickness. The latter analysis also reveals geometrical aspects of the reaction mechanism. Experiments have been carried out with CaCO$$_3$$ 3 and BaCO$$_3$$ 3 films. The simple geometry of the films and their relatively fast heat and gas transport allow the reaction kinetics to be easily explored.

Prognostic value of cardiopulmonary exercise test in patients with acute myocardial infarction after percutaneous coronary intervention

To determine the independent risk factors of cardiopulmonary exercise test (CPET) parameters related to adverse prognostic events within 5 years in patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI), and establish a prediction model for the occurrence of adverse events within 5 years to provide a reference for cardiac rehabilitation training. From August 2015 to December 2021, patients who underwent PCI for AMI and completed CPET within 1–2 weeks after surgery before discharge from the Department of Cardiovascular Medicine of Zhengzhou Central Hospital Affiliated to Zhengzhou University, Henan Provincial Hospital of Traditional Chinese Medicine, and Anyang District Hospital were selected as participants. Univariate and multivariate analyses were used to screen for independent risk factors associated with 5-year adverse events. Feature importance was interpreted using SHapley Additive exPlanations (SHAP), and a logistic regression model was established for prediction. A receiver operating characteristic (ROC) curve was constructed to evaluate the performance of the prediction model. Calibration was assessed by the Hosmer–Lemeshow test and the calibration curve. In total, 375 patients met the inclusion criteria. Based on whether adverse events occurred during the 5-year follow-up period, the patients were divided into two groups: the event group (n = 53) and the non-event group (n = 322). Peak oxygen uptake (peakVO2), carbon dioxide ventilation equivalent slope (VE/VCO2slop), and peak end-tidal carbon dioxide partial pressure (PETCO2) were three independent risk factors for re-acute myocardial infarction (re-AMI), heart failure (HF), and even death after PCI for AMI (P < 0.05). The SHAP plots demonstrated that the significant contributors to model performance were related to peakVO2, VE/VCO2slop, and PETCO2. The risk of adverse events was significantly reduced when the peakVO2 was ≥ 20 mL/kg/min and the VE/VCO2slop was < 33. The ROC curves of the three models were drawn, including the no-event and event groups, re-AMI group, and HF group, which performed well, with AUC of 0.894, 0.760, and 0.883, respectively. The Hosmer–Lemeshow test showed that the three models were a good fit (P > 0.05). The calibration curve of the three models was close to the ideal diagonal lines. CPET parameters can predict the prognosis of adverse events within 5 years after PCI in patients with AMI and provide a theoretical basis for cardiac rehabilitation training.

Stability of passive film and pitting susceptibility of 316 L stainless steel in the aggressive oilfield environment containing Cl−-CO2-O2

In this paper, the effects of chloride ions, oxygen, and carbon dioxide on the corrosion resistance of passive films formed on 316 L stainless steel were investigated in the aggressive oilfield environment using electrochemical testing and microscopic characterization techniques. The results showed that Cl− accelerated the anodic dissolution of the metal and compromised the structure and densification of the passive film, thus reducing its corrosion resistance. An increase in the partial pressure of carbon dioxide initially promotes pitting, but subsequently inhibited further corrosion development. The presence of oxygen enhanced the cathodic reaction and passive film formation, effectively preventing the invasion of aggressive chloride ions, thus inhibiting further corrosion. These findings provide a significant scientific basis for material selection and protection of oil extraction equipment in oilfield environments.

Prevalence and Neurological Outcomes of Comatose Patients With Extracorporeal Membrane Oxygenation

To investigate prevalence, risk factors, and in-hospital outcomes of comatose extracorporeal membrane oxygenation (ECMO) patients. Retrospective observational. Tertiary academic hospital. Adults received venoarterial (VA) or venovenous (VV) ECMO support between November 2017 and April 022. None. We defined 24-hour off sedation as no sedative infusion (except dexmedetomidine) or paralytics administration over a continuous 24-hour period while on ECMO. Off-sedation coma (comaoff) was defined as a Glasgow Coma Scale score of ≤8 after achieving 24-hour off sedation. On-sedation coma (comaon) was defined as a Glasgow Coma Scale score of ≤8 during the entire ECMO course without off sedation for 24 hours. Neurological outcomes were assessed at discharge using the modified Rankin scale (good, 0-3; poor, 4-6). We included 230 patients (VA-ECMO 143, 65% male); 24-hour off sedation was achieved in 32.2% VA-ECMO and 26.4% VV-ECMO patients. Among all patients off sedation for 24 hours (n = 69), 56.5% VA-ECMO and 52.2% VV-ECMO patients experienced comaoff. Among those unable to be sedation free for 24 hours (n = 161), 50.5% VA-ECMO and 17.2% VV-ECMO had comaon. Comaoff was associated with poor outcomes (p < 0.05) in VA-ECMO and VV-ECMO groups, whereas comaon only impacted the VA-ECMO group outcomes. In a multivariable analysis, requirement of renal replacement therapy was an independent risk factor for comaoff after adjusting for ECMO configuration, after adjusting for ECMO configuration, acute brain injury, pre-ECMO partial pressure of oxygen in arterial blood, partial pressure of carbon dioxide in arterial blood, pH, and bicarbonate level (worst value within 24 hours before cannulation). Comaoff was common and associated with poor outcomes at discharge. Requirement of renal replacement therapy was an independent risk factor.

Current incidence, risk factor and outcome of acute respiratory distress syndrome in Nasser Institute ICU, Cairo, Egypt

Abstract Background Acute respiratory distress syndrome (ARDS) represents the severe end of a spectrum of acute lung injury due to many different insults. It manifests as acute and persistent lung inflammation with increased lung permeability. Aim of the study To assess the current incidence, risk factors and outcome of acute respiratory distress syndrome at Nasser Institute ICU during the period from January 2019 till the end of July 2019. Methodology The study enrolled 50 patients who were admitted to Nasser Institute ICU and met the Berlin criteria for ARDS during the study period. Results The incidence of ARDS was (3.12%), 54% of which were severe, 26% were moderate, and 20% were mild. Mortality rate was 52%, 88.46% of which were severe cases. Severity index was positively correlated with mortality rate (P- value &amp;lt;0.001). Pneumonia with sepsis was the most common risk factor (74%) and had statistically significant positive correlation with mortality (P = 0.017). Conclusion Incidence of ARDS was relatively small at our institute (3.12%), yet, it has a serious and a potentially fatal outcome with high mortality rate (52%). Key words: Acute Respiratory Distress Syndrome, ARDS, ICU, incidence, risk factor, outcome, mortality, Nasser Institute. Abbreviations: ARDS: Acute Respiratory Distress Syndrome. PaO2: Partial pressure of oxygen. FiO2: Fraction of inspired oxygen. PEEP : Positive end expiratory pressure.TV: Tidal volume. ABG: Arterial blood gases. PH: potential hydrogen. PaCO2: partial pressure of carbon dioxide. HCO3: Bicarbonate. SO2: blood oxygen saturation. ICU: intensive care unit.

A mapped dataset of surface ocean acidification indicators in large marine ecosystems of the United States

Mapped monthly data products of surface ocean acidification indicators from 1998 to 2022 on a 0.25° by 0.25° spatial grid have been developed for eleven U.S. large marine ecosystems (LMEs). The data products were constructed using observations from the Surface Ocean CO2 Atlas, co-located surface ocean properties, and two types of machine learning algorithms: Gaussian mixture models to organize LMEs into clusters of similar environmental variability and random forest regressions (RFRs) that were trained and applied within each cluster to spatiotemporally interpolate the observational data. The data products, called RFR-LMEs, have been averaged into regional timeseries to summarize the status of ocean acidification in U.S. coastal waters, showing a domain-wide carbon dioxide partial pressure increase of 1.4 ± 0.4 μatm yr−1 and pH decrease of 0.0014 ± 0.0004 yr−1. RFR-LMEs have been evaluated via comparisons to discrete shipboard data, fixed timeseries, and other mapped surface ocean carbon chemistry data products. Regionally averaged timeseries of RFR-LME indicators are provided online through the NOAA National Marine Ecosystem Status web portal.

Identification of symptom clusters and change trajectories in patients with acute exacerbation of chronic obstructive pulmonary disease

Aim and objectivesThis study aimed to identify symptom cluster (SC) patterns and change trajectories in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), the correlation of the SCs with laboratory and imaging indicators, and the intrinsic association of the SCs with prognostic outcomes and disease burden. MethodSymptom information was collected using a digital evaluation scoring system at the time of admission, on the third day after admission, and upon discharge. Laboratory and imaging examination data were compiled simultaneously. Exploratory factor analysis was used to identify the AECOPD SCs. The number of factors (clusters) was determined by examining factors with eigenvalues ≥1.0, using 0.50 for factor loadings as the minimum cut-off value. Spearman's correlation analysis was used to explore the link between the SCs and laboratory and imaging indicators, as well as the relationship between the severity of the symptoms in different clusters, prognostic outcomes, and disease burden. ResultsThis study included 148 patients. Three SCs were identified: activity-nutrition SC, breath-sleep SC and respiratory SC. Correlation analysis indicated a connection between the activity-nutrition SC and the white blood cell count, and serum sodium and potassium levels, whereas the breath-sleep SC was correlated with white blood cells and eosinophil counts, serum potassium level, and pleural effusion. Additionally, the respiratory SC was associated with serum calcium and magnesium levels, the partial pressure of carbon dioxide, and C-reactive protein (CRP) level. There was a positive correlation between the activity-nutrition SC and hospitalization cost, as well as between the breath-sleep SC and both the hospitalization length and cost. ConclusionPatients with AECOPD presented three SCs that affected the length and cost of hospitalization. Concurrently, the severity of the symptoms in the clusters was related to white blood cell and eosinophil counts; serum sodium, potassium, calcium, and magnesium levels; CRP level; the partial pressure of carbon dioxide; and pleural effusion, indicating that the symptoms in each clusters may share related physiological mechanisms. An in-depth exploration of the pathogenesis and intervention paths of health problems is of great significance for promoting precision nursing.

Network Meta-analysis of Chinese patent medicines in treatment of chronic pulmonary heart disease

Network Meta-analysis was performed to compare the efficacy and safety of Chinese patent medicines in treating chronic pulmonary heart disease. CNKI, VIP, Wanfang, SinoMed, PubMed, Web of Science, EMbase, and Cochrane Library were searched for randomized controlled trial(RCT) of treating chronic pulmonary heart disease with Chinese patent medicines with the time interval from inception to December 2023. The Cochrane risk-of-bias tool was used for quality assessment of the included articles. RevMan 5.4 and Stata 17.0 were employed to establish the risk of bias map and perform the network Meta-analysis, respectively. Ultimately, a total of 95 RCTs involving 8 787 cases and 11 different Chinese patent medicines were included. Network Meta-analysis yielded the following results based on the surface under the cumulative ranking curve(SUCRA).(1)In terms of cardiac function improves clinical total effective rate, SUCRA the top three were Wenxin Granules + conventional western medicine, Tongxinluo Capsules + conventional western medicine, and Qishen Yiqi Dropping Pills + conventional western medicine.(2)For improving forced expiratory volume in the first se-cond(FEV1), SUCRA the top three were Danting Feixin Granules + conventional western medicine, Tongxinluo Capsules + conventional western medicine, and Bufei Huoxue Capsules + conventional western medicine.(3)Regarding increasing the FEV1/forced vital capacity(FVC%) value, SUCRA the top three were Qili Qiangxin Capsules + conventional western medicine, Shexiang Baoxin Pills + conventional western medicine, and Qishen Yiqi Dropping Pills + conventional western medicine.(4)In terms of increasing the partial pressure of oxygen(PaO_2), SUCRA the top three were Qili Qiangxin Capsules + conventional western medicine, Qishen Yiqi Dropping Pills + conventional western medicine, and Shexiang Baoxin Pills + conventional western medicine.(5)In terms of reducing the partial pressure of carbon dioxide(PaCO_2), SUCRA the top three were Tongxinluo Capsules + conventional western medicine, Qishen Yiqi Dropping Pills + conventional western medicine, and Shexiang Baoxin Pills + conventional western medicine.(6)In terms of increasing left ventricular ejection fraction(LVEF), SUCRA the top three were Bufei Huoxue Capsules + conventional western medicine, Qishen Yiqi Dropping Pills + conventional western medicine, and Shexiang Baoxin Pills + conventional western medicine.(7)In terms of decreasing brain natriu-retic peptide(BNP), SUCRA the top three were Compound Danshen Dropping Pills + conventional western medicine, Qili Qiangxin Capsules + conventional western medicine, and Tongxinluo Capsules + conventional western medicine.(8)In terms of improving the hematocrit level, SUCRA the top three were Qishen Yiqi Dropping Pills + conventional western medicine, Compound Danshen Dropping Pills + conventional western medicine, and Tongxinluo Capsules + conventional western medicine. In terms of safety, 26 RCTs reported adverse reactions, which primarily involved the circulatory and digestive systems. The combination of Chinese patent medicines with conventional western medicine has demonstrated enhanced therapeutic effects on chronic pulmonary heart disease. However, due to the varying quality and sample sizes of included studies and the absence of direct comparisons between Chinese patent medicines, the conclusions should be further validated by multicenter studies with larger sample sizes and higher methodological rigor.

Prospective Evaluation of a Modified Apnea Test in Brain Death Candidates that Does Not Require Disconnection from the Ventilator.

The apnea test (AT) is an important component in the determination of brain death/death by neurologic criteria (BD/DNC) and often entails disconnecting the patient from the ventilator followed by tracheal oxygen insufflation to ensure adequate oxygenation. To rate the test as positive, most international guidelines state that a lack of spontaneous breathing must be demonstrated when the arterial partial pressure of carbon dioxide (PaCO2)≥ 60mm Hg. However, the loss of positive end-expiratory pressure that is associated with disconnection from the ventilator may cause rapid desaturation. This, in turn, can lead to cardiopulmonary instability (especially in patients with pulmonary impairment and diseases such as acute respiratory distress syndrome), putting patients at increased risk. Therefore, this prospective study aimed to investigate whether a modified version of the AT (mAT), in which the patient remains connected to the ventilator, is a safer yet still valid alternative. The mAT was performed in all 140 BD/DNC candidates registered between January 2019 and December 2022: after 10min of preoxygenation, (1) positive end-expiratory pressure was increased by 2mbar (1.5mm Hg), (2) ventilation mode was switched to continuous positive airway pressure, and (3) apnea back-up mode was turned off (flow trigger 10 L/min). The mAT was considered positive when spontaneous breathing did not occur upon PaCO2 increase to ≥ 60mm Hg (baseline 35-45mm Hg). Clinical complications during/after mAT were documented. The mAT was possible in 139/140 patients and had a median duration of 15min (interquartile range 13-19min). Severe complications were not evident. In 51 patients, the post-mAT arterial partial pressure of oxygen (PaO2)was lower than the pre-mAT PaO2, whereas it was the same or higher in 88 cases. In patients with pulmonary impairment, apneic oxygenation during the mAT improved PaO2. In 123 cases, there was a transient drop in blood pressure at the end of or after the mAT, whereas in 12 cases, the mean arterial pressure dropped below 60mm Hg. The mAT is a safe and protective means of identifying patients who no longer have an intact central respiratory drive, which is a critical factor in the diagnosis of BD/DNC. Clinical trial registration DRKS, DRKS00017803, retrospectively registered 23.11.2020, https://drks.de/search/de/trial/DRKS00017803.

A randomized controlled trial evaluating the effect of providing a rest period during long-distance transportation of surplus dairy calves: Part II. Effect on hematological variables

The objective of this randomized controlled trial was to determine if providing a rest stop including provision of feed and water between periods of continuous transportation mitigates the effect of long-distance transportation on markers of energy status and hydration in calves transported by road for 16 h. This study was conducted between September 2022 to January 2023 and included male and female Holstein and crossbred dairy calves ≥7 d old from 2 commercial dairy farms in Ontario, Canada (n = 96). On the day before transportation, calves were enrolled and randomly assigned to one of 2 treatment groups: (1) continuous transportation by road for 16 h or (2) 8 h of transport, 8 h of rest, and a further 8 h of transport to a single calf-raising facility. Calves that received a rest stop were fed 2 L of milk replacer at the time of unloading for the rest period and again immediately before reloading for the second leg of the journey. Blood samples were collected before and after transportation as well as daily for 3 d following arrival to the calf-raising facility. Serum was analyzed for concentrations of BHB, nonesterified fatty acids (NEFA), haptoglobin, and creatine kinase, and acid-base disturbances were evaluated within 1 h of collection of whole blood to assess glucose, sodium, potassium, ionized calcium, hematocrit, hemoglobin, pH, base excess, partial pressure of oxygen, total carbon dioxide, bicarbonate, partial pressure of carbon dioxide, and oxygen saturation. Mixed linear regression models with repeated measures were built to assess the effect of treatment group, age at transportation, breed, and sex on these parameters. Immediately after transportation, calves that received the rest period had lower BHB (-68.04 μmol/L, 95% CI: -99.59 to -36.49), NEFA (-0.14 mmol/L, 95% CI -0.22 to -0.07), and sodium (-1.10 mmol/L, 95% CI = -2.18 to -0.02), and higher glucose (0.48 mmol/L, 95% CI = 0.21 to 0.74), potassium (0.27 mmol/L, 95% CI = 0.11 to 0.43), ionized calcium (0.06 mmol/L, 95% CI = 0.03 to 0.08), and oxygen saturation (8.76%, 95% CI = 1.61 to 15.91) compared with calves that were continuously transported for 16 h. Additionally, calves transported between 11 and 12 d old had lower hematocrit (-1.22%, 95% CI = -2.19 to -0.25), hemoglobin (-3.07 g/L, 95% CI = -5.70 to -0.43), haptoglobin (-0.13 g/L, 95% CI = -0.23 to -0.02), and potassium (-0.13 mmol/L, 95% CI = -0.22 to -0.04) and higher sodium (0.83 mmol/L, 95% CI = 0.03 to 1.63) than 7 to 8 d old calves. Furthermore, calves that were 13 to 24 d old at transport had lower haptoglobin (-0.16 g/L, 95% CI = -0.27 to -0.06) and potassium (-0.14 mmol/L, 95% CI = -0.23 to -0.05), and higher sodium (1.02 mmol/L, 95% CI = 0.22 to 1.82) and ionized calcium (0.02 mmol/L, 95% CI = 0.002 to 0.035) compared with calves transported at 7 to 8 d old. The results of this trial demonstrate that a rest period improves energy status upon arrival to a calf-raising facility, suggesting that the benefit of a rest period may be mostly related to the provision of mid-journey milk meals.

High‐Resolution Neural Network Demonstrates Strong CO2 Source‐Sink Juxtaposition in the Coastal Zone

AbstractThe role of coastal oceans in regulating atmospheric carbon dioxide remains poorly quantified and understood. Here, we use a two‐step neural network approach to generate estimates from sparse observational data in the coastal Northeast Pacific Ocean at an unprecedented spatial resolution of 1/12° with coverage in the nearshore (0–25 km offshore). We compiled partial pressure of carbon dioxide (pCO2) observations as well as a range of predictor variables including satellite‐based and physical oceanographic reanalysis products. With the predictor variables representing processes affecting pCO2, we created non‐linear relationships to interpolate observations from 1998 to 2019. Compared to in situ shipboard and mooring observations, our coastal pCO2 product captures broad spatial patterns and seasonal cycle variability well. A sensitivity analysis identifies that the parameters responsible for the neural network's ability to capture regional pCO2 variability are associated with mechanistic processes, including mixed layer deepening, mesoscale eddies, and gyre upwelling. Using wind speed and atmospheric CO2, we calculated air‐sea CO2 fluxes. We report an anticorrelation between annual air‐sea CO2 flux and its seasonal amplitude with the relationship driven by circulation, opposing seasonal upwelling/relaxation versus downwelling, and the effects of winter mixing and primary productivity. We show that the inclusion of nearshore net outgassing fluxes lowers the overall regional net flux. Overall, our results suggest that the region is a net sink (−0.7 mol m−2 yr−1) for atmospheric CO2 with trends indicating increasing oceanic uptake due to strong connectivity to subsurface waters.