Interpretation of acid-base metabolism on arterial blood gas samples via machine learning algorithms.

BACKGROUND: Arterial blood gas evaluation is crucial for critically ill patients, as it provides essential information about acid-base metabolism and respiratory balance, but evaluation can be complex and time-consuming. Artificial intelligence can perform tasks that require human intelligence, and it is revolutionizing healthcare through technological advancements. AIM: This study aims to assess arterial blood gas evaluation using artificial intelligence algorithms. METHODS: The study included 21.541 retrospective arterial blood gas samples, categorized into 15 different classes by experts for evaluating acid-base metabolism status. Six machine learning algorithms were utilized; accuracy, balanced accuracy, sensitivity, specificity, precision, and F1 values of the models were determined; and ROC curves were drawn to assess areas under the curve for each class. Evaluation of which sample was estimated in which class was conducted using the confusion matrices of the models. RESULTS: The bagging classifier (BC) model achieved the highest balanced accuracy with 99.24%, whereas the XGBoost model reached the highest accuracy with 99.66%. The BC model shows 100% sensitivity for nine classes and 100% specificity for 10 classes, and the model correctly predicted 6438 of 6463 test samples and achieved an accuracy of 99.61%, with an area under the curve > 0.9 in all classes on a class basis. CONCLUSION: The machine learning models developed exhibited remarkable accuracy, sensitivity, and specificity in predicting the status of acid-base metabolism. However, implementing these models can aid clinicians, freeing up their time for more intricate tasks.

Differences in Exercise Capacity, Ventilatory Efficiency, and Gas Exchange between Patients with Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension Residing at High Altitude.

Background: Cardiopulmonary exercise testing (CPET) assesses exercise capacity and causes of exercise limitation in patients with pulmonary hypertension (PH). At altitude, changes occur in the ventilatory pattern and a decrease in arterial oxygen pressure in healthy; these changes are increased in patients with cardiopulmonary disease. Our objective was to compare the response to exercise and gas exchange between patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) residing at the altitude of Bogotá (2640 m). Methods: All patients performed an incremental CPET with measurement of oxygen consumption ( VO 2 ), dead space (VD/VT), ventilatory equivalents (VE/ VCO 2 ), and alveolar-arterial oxygen gradient ( PA-aO 2 ). X 2 test and one-way analysis of variance were used for comparisons between PAH and CTEPH. Results: We included 53 patients, 29 with PAH, 24 with CTEPH, and 102 controls as a reference of the normal response to exercise at altitude. CTEPH patients had a higher New York Health Association (NYHA) functional class than PAH (p = 0.037). There were no differences between patients with PAH and CTEPH in hemodynamics and VO 2 % of predicted (67.8 ± 18.7 vs. 66.0 ± 19.8, p < 0.05), but those with CTEPH had higher dyspnea, VD/VT (0.36 ± 0.09 vs. 0.23 ± 0.9, p < 0.001), VE/ VCO 2 (45.8 ± 7.1 vs. 39.3 ± 5.6, p < 0.001), and PA-aO 2 (19.9 ± 7.6 vs. 13.5 ± 7.6, p < 0.001) than PAH patients. Conclusions: At altitude, patients with PH present severe alterations in gas exchange during exercise. There were no differences in exercise capacity between PAH and CTEPH, but patients with CTEPH had more dyspnea and greater alterations in gas exchange during exercise. CPET made it possible to identify alterations related to the pathophysiology of CTEPH that could explain the functional class and dyspnea in these patients.

Tropine exacerbates the ventilatory depressant actions of fentanyl in freely-moving rats.

Our lab is investigating the efficacy profiles of tropine analogs against opioid-induced respiratory depression. The companion manuscript reports that the cell-permeant tropeine, tropine ester (Ibutropin), produces a rapid and sustained reversal of the deleterious actions of fentanyl on breathing, alveolar-arterial (A-a) gradient (i.e., index of alveolar gas exchange), and arterial blood-gas (ABG) chemistry in freely-moving male Sprague Dawley rats, while not compromising fentanyl analgesia. We report here that in contrast to Ibutropin, the injection of the parent molecule, tropine (200 µmol/kg, IV), worsens the adverse actions of fentanyl (75 µg/kg, IV) on ventilatory parameters (e.g., frequency of breathing, tidal volume, minute ventilation, peak inspiratory and expiratory flows, and inspiratory and expiratory drives), A-a gradient, ABG chemistry (e.g., pH, pCO2, pO2, and sO2), and sedation (i.e., the righting reflex), while not affecting fentanyl antinociception (i.e., the tail-flick latency) in freely-moving male Sprague Dawley rats. These data suggest that tropine augments opioid receptor-induced signaling events that mediate the actions of fentanyl on breathing and alveolar gas exchange. The opposite effects of Ibutropin and tropine may result from the ability of Ibutropin to readily enter peripheral and central cells. Of direct relevance is that tropine, resulting from the hydrolysis of Ibutropin, would combat the Ibutropin-induced reversal of the adverse effects of fentanyl. Because numerous drug classes, such as cocaine, atropine, and neuromuscular blocking drugs contain a tropine moiety, it is possible that their hydrolysis to tropine has unexpected/unintended consequences. Indeed, others have found that tropine exerts the same behavioral profile as cocaine upon central administration. Together, these data add valuable information about the pharmacological properties of tropine.

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.

Association between Peripheral Arterial Lactate Levels and Malignant Brain Edema Following Endovascular Treatment for Ischemic Stroke.

AIMS: To investigate the factors of postoperative malignant brain edema (MBE) in patients with acute ischemic stroke (AIS) treated with endovascular treatment (EVT). BACKGROUND: MBE is a severe complication following EVT for AIS, and it is essential to identify risk factors early. Peripheral arterial lactate (PAL) levels may serve as a potential predictive marker for MBE. OBJECTIVE: To determine whether immediate postoperative PAL levels and the highest PAL level within 24 hours of EVT are independently associated with MBE development in AIS patients. METHODS: We retrospectively analyzed patients with AIS who underwent EVT from October 2019 to October 2022. Arterial blood was collected every 8 h after EVT to measure PAL, and record the immediate postoperative PAL and the highest PAL level within 24 h. Brain edema was evaluated using brain computed tomography scans within 7 days of EVT. RESULTS: The study included 227 patients with a median age of 71 years, of whom 59.5% were male and MBE developed in 25.6% of patients (58/227). Multivariate logistic regression analysis showed that the immediate postoperative PAL (odds ratio, 1.809 [95% confidence interval (CI), 1.215-2.693]; p = 0.004) and the highest PAL level within 24 h of EVT (odds ratio, 2.259 [95% CI, 1.407-3.629]; p = 0.001) were independently associated with MBE. The area under the curve for predicting MBE based on the highest PAL level within 24 hours of EVT was 0.780 (95% CI, 0.711-0.849). CONCLUSION: Early increase in PAL levels is an independent predictor of MBE after EVT in AIS patients.

Utilization of Multi-Parameter Blood Gas Analysis in Prehospital Emergency Medicine-A Scoping Review.

BACKGROUND: Prehospital blood gas analysis (BGA) is an evolving field that offers the potential for early identification and management of critically ill patients. However, the utility and accuracy of prehospital BGA are subjects of ongoing debate. OBJECTIVES: We aimed to provide a comprehensive summary of the current literature on prehospital BGA, including its indications, methods, and feasibility. METHODS: We performed a scoping review of prehospital BGA. A thorough search of the PubMed, Embase, and Web of Science databases was conducted to identify relevant studies focusing on prehospital BGA in adult patients. RESULTS: Fifteen studies met the inclusion criteria. Prehospital BGA was most frequently performed in patients in out-of-hospital cardiac arrest, followed by traumatic and nontraumatic cases. The parameters most commonly analyzed were pH, pCO2, pO2, and lactate. Various sampling methods, including arterial, venous, and intraosseous, were reported for prehospital BGA. While prehospital BGA shows promise in facilitating early identification of critical patients and guiding resuscitation efforts, logistical challenges are to be considered. The handling of preclinical BGA is described as feasible and useful in most of the included studies. CONCLUSION: Prehospital BGA holds significant potential for enhancing patient care in the prehospital setting, though technical challenges need to be considered. However, further research is required to establish optimal indications and demonstrate the benefits for prehospital BGA in specific clinical contexts.

Effects of nursing team communication and collaboration on treatment outcomes in intensive care unit patients with severe pneumonia.

BACKGROUND: Severe pneumonia is a common severe respiratory infection worldwide, and its treatment is challenging, especially for patients in the intensive care unit (ICU). AIM: To explore the effect of communication and collaboration between nursing teams on the treatment outcomes of patients with severe pneumonia in ICU. METHODS: We retrospectively analyzed 60 patients with severe pneumonia who were treated at the ICU of the hospital between January 1, 2021 and December 31, 2023. We compared and analyzed the respiratory mechanical indexes [airway resistance (Raw), mean airway pressure (mPaw), peak pressure (PIP)], blood gas analysis indexes (arterial oxygen saturation, arterial oxygen partial pressure, and oxygenation index), and serum inflammatory factor levels [C-reactive protein (CRP), procalcitonin (PCT), cortisol (COR), and high mobility group protein B1 (HMGB1)] of all patients before and after treatment. RESULTS: Before treatment, there was no significant difference in respiratory mechanics index and blood gas analysis index between 2 groups (P > 0.05). However, after treatment, the respiratory mechanical indexes of patients in both groups were significantly improved, and the improvement of Raw, mPaw, plateau pressure, PIP and other indexes in the combined group after communication and collaboration with the nursing team was significantly better than that in the single care group (P < 0.05). The serum CRP and PCT levels of patients were significantly decreased, and the difference was statistically significant compared with that of nursing group alone (P < 0.05). The levels of serum COR and HMGB1 before and after treatment were also significantly decreased between the two groups. CONCLUSION: The communication and collaboration of the nursing team have a significant positive impact on respiratory mechanics indicators, blood gas analysis indicators and serum inflammatory factor levels in the treatment of severe pneumonia patients in ICU.

Analysis of arterial blood gas values when discarding different volumes of blood samples in an arterial heparin blood collector during thoracoscopic surgery.

BACKGROUND: Arterial blood gas analysis (ABGA) plays a vital role in emergency and intensive care, which is affected by many factors, such as different instrumentation, temperature, and testing time. However, there are still no relevant reports on the difference in discarding different blood volumes on ABGA values. METHODS: We enrolled 54 patients who underwent thoracoscopic surgery and analysed differences in blood gas analysis results when different blood volumes were discarded from the front line of the arterial heparin blood collector. A paired t test was used to compare the results of the same patient with different volumes of blood discarded from the samples. The difference was corrected by Bonferroni correction. RESULTS: Our results demonstrated that the PaO2, PaCO2, and THbc were more stable in the 4th ml (PaO2 = 231.3600 ± 68.4878 mmHg, PaCO2 = 41.9232 ± 7.4490 mmHg) and 5th ml (PaO2 = 223.7600 ± 12.9895 mmHg, PaCO2 = 42.5679 ± 7.6410 mmHg) blood sample than in the 3rd ml (PaO2 = 234.1000 ± 99.7570 mmHg, PaCO2 = 40.6179 ± 7.2040 mmHg). CONCLUSION: It may be more appropriate to discard the first 3 ml of blood sample in the analysis of blood gas results without wasting blood samples.

Comparison of Blood Gas Analysis and Auto-Analyzer Results for Sodium and Potassium Levels in Elderly and Non-elderly Adult Emergency Department Patients.

Objectives This study aims to evaluate the concordance between blood gas and biochemical measurement methods for sodium and potassium levels in elderly and non-elderly patients within an emergency department (ED) setting. Methods A retrospective method comparison study was conducted at an ED from February 1, 2023, to March 1, 2023. The study included 414 patients, categorized into "elderly" (aged 65 and above; n = 138, 33.3%) and "non-elderly" (aged 18 to 64; n = 276, 66.7%) groups. Concordance was assessed using Bland-Altman, Passing-Bablok, and Lin's concordance correlation methods. Results In sodium measurements, the elderly group exhibited an average bias of -1.52 mEq/L (95% confidence interval [CI] -2.12 to -0.92), with lower and upper limits of agreement (LoA) at -8.46 and 5.42 mEq/L, respectively, indicating a broader variance than non-elderly patients, who showed an average bias of -0.82 mEq/L with limits of -4.97 to 3.32 mEq/L. For potassium, the elderly group's average bias was -0.46 mEq/L (95% CI -0.36 to -0.57), with limits of agreement from -1.68 to 0.75 mEq/L, compared to non-elderly patients with a bias of -0.29 mEq/L and limits of -0.71 to 0.13 mEq/L. Furthermore, concordance correlation coefficients revealed a reduced agreement in the elderly for both sodium (r ccc = 0.799) and potassium (r ccc = 0.529) compared to the non-elderly cohort (sodium r ccc = 0.821, potassium r ccc = 0.715). Conclusion The study identifies significant discrepancies in sodium and potassium levels between elderly and non-elderly patients, suggesting a need for diagnostic precision. It emphasizes the importance of customizing diagnostic approaches to better serve the elderly population in EDs.

An Assessment of the Relationships Between Umbilical Cord Blood Gas Analysis, APGAR (Appearance, Pulse, Grimace, Activity, and Respiration) Scores, and Neonatal Outcomes.

Introduction Intrapartum hypoxic-ischemic injury is a condition that significantly affects neonatal health and, therefore, needs to be attended to urgently. Umbilical cord blood gas analysis (BGA) results and APGAR (appearance, pulse, grimace, activity, and respiration) scores are commonly used to assess birth asphyxia and the severity of neonatal acidemia. In this context, this study was conducted to investigate the correlations of BGA results and APGAR scores with neonatal outcomes to determine the combined value of BGA results and APGAR scores in neonatal health assessment. Methods The sample of this retrospective cohort study consisted of 593 consecutive-term newborns delivered in a tertiary referral center in Turkey between January 2020 and December 2022. All newborns' maternal, delivery, and neonatal characteristics, BGA results, and APGAR scores were analyzed to determine correlations with composite adverse neonatal outcomes. The study's primary outcome was defined as the rate of the composite adverse neonatal outcomes, whereas the secondary outcomes were determined as the impact of maternal and neonatal characteristics on composite neonatal morbidity and the correlation between the one- and five-minute APGAR scores and umbilical cord BGA parameters. Results Of the 593 infants included in the study, 191 (32.2%) infants experienced composite adverse neonatal outcomes, primarily mechanical ventilation (47.7%), followed by respiratory distress/syndrome (35.6%). Significant correlations were detected between composite adverse neonatal outcomes and advanced maternal age (p = 0.025), cesarean section history (p < 0.001), preterm delivery (p < 0.001), lower one- and five-minute APGAR scores (p < 0.001 for both cases), and acidemia severity (p = 0.007). However, the correlations between BGA parameters and APGAR scores were weak (r < 0.2). Conclusion This study investigated the correlations between neonatal mortality and morbidity and maternal factors, delivery characteristics, and fetal features, including one- and five-minute APGAR scores and BGA parameters. Nevertheless, weak correlations between BGA parameters and APGAR scores warrant further comprehensive prospective studies.

Australian and New Zealand Society of Respiratory Science position statement for arterial blood gas sampling.

The assessment of gas exchange under varying ambient and metabolic conditions is an important and fundamental investigation of respiratory function. The gold standard is an arterial blood gas (ABG) sample; however, the procedure is not universally performed by medical scientists, is not standardised, and is typically taught by a subjective Halsted 'see one, do one' approach. The Australian and New Zealand Society of Respiratory Science recognised the need to create an ABG position statement that includes the required pre-requisite education, an evidence-based procedure and the minimum reporting and competency assessment requirements. This position statement aims to minimise patient discomfort, to improve puncture success rate and reduce the potential for sample handling and analysis error. Importantly, this position statement translates to all relevant health professionals, including medical officers, scientists, nursing staff and allied health.

High altitudes and partial pressure of arterial oxygen in patients with chronic obstructive pulmonary disease - A systematic review and meta-analysis.

IMPORTANCE: Prior study in healthy subjects has shown a reduction of partial pressure of arterial oxygen (PaO2) by -1.60 kPa/kilometre of altitude gain. However, the association of altitude-related change in PaO2 and altitude-related adverse health effects (ARAHE) in patients with chronic obstructive pulmonary disease (COPD) remain unknown. OBJECTIVE: To provide an effect size estimate for the decline in PaO2 with each kilometre of altitude gain and to identify ARAHE in relation to altitude in patients with COPD. www.crd.york.ac.uk/prospero: CRD42020217938. DATA SOURCES: A systematic search of PubMed and Embase was performed from inception to May 30, 2023. STUDY SELECTION: Peer-reviewed and prospective studies in patients with COPD staying at altitudes >1500 m providing arterial blood gases within the first 3 days at the target altitude. DATA EXTRACTION AND SYNTHESIS: Aggregate data (AD) on study characteristics were extracted, and individual patient data (IPD) were requested. Estimates were pooled using random-effects meta-analysis. MAIN OUTCOME AND MEASURES: Relative risk estimates and 95 % confidence intervals for the association between PaO2 and altitude in patients with COPD. RESULTS: Thirteen studies were included in the AD analysis, of which 6 studies (222 patients, 45.2 % female) provided IPD, thus were included in the quantitative analysis. The estimated effect size of PaO2 was -0.84 kPa [95 %CI, -0.92 to -0.76] per 1000 m of altitude gain (I2=65.0 %, P < 0.001). In multivariable regression analysis, COPD severity, baseline PaO2, age and time spent at altitude were predictors for PaO2 at altitude. Overall, 37.8 % of COPD patients experienced an ARAHE, whereas older age, female sex, COPD severity, baseline PaO2, and target altitude were predictors for the occurrence of ARAHE (area under ROC curve: 0.9275, P < 0.001). CONCLUSIONS AND RELEVANCE: This meta-analysis, providing altitude-related decrease in PaO2 and risk of ARAHE in patients with COPD ascending to altitudes >1500 m, revealed a lower altitude-related decrease in PaO2 in COPD patients compared with healthy. However, these findings might improve patient care and facilitate decisions about initiating preventive measures against hypoxaemia and ARAHE in patients with COPD planning an altitude sojourn or intercontinental flight, i.e. supplemental oxygen or acetazolamide.

Preadmission metformin use increased the incidence of hyperlactatemia at admission and 30-day in-hospital mortality among T2D patients with heart disease at high risk of hypoxia.

BACKGROUND: Surprisingly, despite the high prevalence of metformin use in type 2 diabetes (T2D) patients with heart disease, limited safety data is available regarding metformin use in patients with acute and critical heart disease. METHODS: In this single-center retrospective study, patients admitted to the cardiology department for heart failure (HF) or acute coronary syndrome (ACS) between December 2013 and December 2021 and who underwent arterial blood gas analysis at admission with an estimated glomerular clearance rate of ≥45 ml/min/1.73 m2 were identified. The incidences of hyperlactatemia, acidosis, and 30-day in-hospital mortality were compared between preadmission metformin users and nonusers. RESULTS: Of 526 admissions, 193/193 metformin users/nonusers were selected in a propensity score-matched model. Metformin users had greater lactate levels (2.55 ± 2.07 mmol/l vs. 2.00 ± 1.80 mmol/l P < 0.01), a greater incidence of hyperlactatemia [odds ratio (OR) = 2.55; 95% confidence interval (CI), 1.63-3.98; P < 0.01] and acidosis (OR = 1.78; 95% CI, 1.00-3.16; P < 0.05) at admission and a greater incidence of in-hospital mortality (OR = 3.83; 95% CI, 1.05-13.94; P < 0.05), especially those with HF/acute myocardial infarction, elderly age, or without preadmission insulin use. CONCLUSIONS: Our results suggest that, compared to metformin nonusers, preadmission use of metformin may be associated with a greater incidence of hyperlactatemia and acidosis at admission and greater 30-day in-hospital mortality among T2D patients with HF or ACS at high risk of hypoxia, particularly those without preadmission insulin use. The safety of metformin in this population needs to be confirmed in prospective controlled trials.

Effectiveness and Outcomes of Noninvasive Positive Pressure Ventilation in Patients With Acute Exacerbations of Chronic Obstructive Pulmonary Disease.

BACKGROUND: Endotracheal intubation and mechanical ventilation in individuals experiencing acute exacerbations of chronic obstructive pulmonary disease (COPD) are associated with several complications. Therefore, utilizing noninvasive positive pressure ventilation (NIPPV) is the suggested initial management for these individuals. The current study was done to assess and compare the clinical and physiological parameters before and after the application of NIPPV and also to evaluate the outcomes of NIPPV. METHODOLOGY: A prospective observational study was conducted on 50 patients with COPD experiencing acute exacerbations. These patients were treated with NIPPV. Measurements of blood pressure, respiratory rate (RR), heart rate (HR), dyspnea using the modified Borg scale, and arterial blood gas (ABG) parameters (pH, PaCO2, and PaO2) were recorded at baseline, one hour, six hours, 24 hours, and daily until discharge. The study's outcomes included the subjects who successfully underwent NIPPV and failed during NIPPV. RESULTS: NIPPV effectively reduced the dyspnea score from 7.24 ± 1.58 at baseline to 5.53 ± 1.82 at one hour, 4.11 ± 1.75 at six hours, 2.60 ± 1.03 at 24 hours, and 1.26 ± 0.44 at the time of discharge. Significant improvements were also observed in HR and RR (P < 0.001). When compared to the baseline, the pH level was significantly maintained, PaCO2 was decreased, and PaO2 was increased at various times. Mortality was observed in four patients. CONCLUSIONS: NIPPV was successful in 42 (84%) patients, with improvements in ABG and pH for early recovery and reduced hospital stay.

FFP2 induced breathing resistance does not affect metabolism and well-being during brisk walking and stair climbing - a randomized controlled trial.

OBJECTIVES: N95 or Type II filtering face pieces (FFP2) are often worn during work hours or on public transportation to prevent airborne infection. The aim of this randomized controlled crossover study is to assess the impact of FFP2 induced breathing resistance on pulmonary function, blood gas values and discomfort during walking and stair climbing. METHODS: N = 16 healthy adults (24.8 ± 2.2 years; 10 females, ) participated. Interventions included (1) six minutes of walking in a 16-meter-long hallway (612 m) and (2) eight minutes of stair climbing in a two-story staircase (420 stairs), both with and without a FFP2 (> 48 h wash-out). Spiroergometric data (Ventilation, breathing frequency, tidal volume, oxygen uptake and carbon dioxide exhalation (primary outcome), end tidal carbon dioxide- and oxygen pressure) and self-reported response (Perceived exertion, dyspnoea and pain) were assessed during activities. Blood gas analysis (capillary carbon dioxide- (pCO2) (primary outcome) and oxygen partial pressure (pO2), pH, lactate and base excess) was measured immediately after cessation of activities. Manipulation effects (FFP2 versus no mask) were tested using repeated measures analyses of variance. RESULTS: Analysis showed no effect of FFP2 on pCO2 or other blood-gas parameters but on carbon dioxide exhalation during walking: (mean 1067, SD 209 ml/min) (mean 1908, SD 426 ml/min) (F(15) = 19.5; p < 0.001; ηp2 = 0.566) compared to no mask wearing (mean 1237, SD 173 ml/min; mean 1908, SD 426 ml/min). Ventilation was decreased and dyspnoea was increased by FFP2 during activities. FFP2 led to lower oxygen uptake and lower end tidal oxygen but higher end tidal carbon dioxide during stair climbing. CONCLUSIONS: FFP2 decreased ventilation based on slower breathing patterns and led to limitations in pulmonary gas exchange and increased subjective dyspnoea. However, invasive diagnostics revealed no signs of clinically relevant metabolic effects immediately after everyday physical activities.

Lung ultrasound score evaluation of the effect of pressure-controlled ventilation volume-guaranteed on patients undergoing laparoscopic-assisted radical gastrectomy.

BACKGROUND: Laparoscopic-assisted radical gastrectomy (LARG) is the standard treatment for early-stage gastric carcinoma (GC). However, the negative impact of this procedure on respiratory function requires the optimized intraoperative management of patients in terms of ventilation. AIM: To investigate the influence of pressure-controlled ventilation volume-guaranteed (PCV-VG) and volume-controlled ventilation (VCV) on blood gas analysis and pulmonary ventilation in patients undergoing LARG for GC based on the lung ultrasound score (LUS). METHODS: The study included 103 patients with GC undergoing LARG from May 2020 to May 2023, with 52 cases undergoing PCV-VG (research group) and 51 cases undergoing VCV (control group). LUS were recorded at the time of entering the operating room (T0), 20 minutes after anesthesia with endotracheal intubation (T1), 30 minutes after artificial pneumoperitoneum (PP) establishment (T2), and 15 minutes after endotracheal tube removal (T5). For blood gas analysis, arterial partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2) were observed. Peak airway pressure (Ppeak), plateau pressure (Pplat), mean airway pressure (Pmean), and dynamic pulmonary compliance (Cdyn) were recorded at T1 and T2, 1 hour after PP establishment (T3), and at the end of the operation (T4). Postoperative pulmonary complications (PPCs) were recorded. Pre- and postoperative serum interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay. RESULTS: Compared with those at T0, the whole, anterior, lateral, posterior, upper, lower, left, and right lung LUS of the research group were significantly reduced at T1, T2, and T5; in the control group, the LUS of the whole and partial lung regions (posterior, lower, and right lung) decreased significantly at T2, while at T5, the LUS of the whole and some regions (lateral, lower, and left lung) increased significantly. In comparison with the control group, the whole and regional LUS of the research group were reduced at T1, T2, and T5, with an increase in PaO2, decrease in PaCO2, reduction in Ppeak at T1 to T4, increase in Pmean and Cdyn, and decrease in Pplat at T4, all significant. The research group showed a significantly lower incidence of PPCs than the control group within 3 days postoperatively. Postoperative IL-1ß, IL-6, and TNF-α significantly increased in both groups, with even higher levels in the control group. CONCLUSION: LUS can indicate intraoperative non-uniformity and postural changes in pulmonary ventilation under PCV-VG and VCV. Under the lung protective ventilation strategy, the PCV-VG mode more significantly improved intraoperative lung ventilation in patients undergoing LARG for GC and reduced lung injury-related cytokine production, thereby alleviating lung injury.

Comparative analysis of neonatal umbilical cord blood gases across various delivery modes at a referral center.

BACKGROUND: This study aimed to address the increasing prevalence of cesarean section and the importance of evaluating newborn health through arterial blood gas analysis. Its primary objective was to compare the umbilical cord blood gas levels in newborns delivered through different delivery methods. METHOD: This retrospective descriptive cross-sectional study included singleton pregnancies with a gestational age between 37 and 42 weeks and infants weighing between 2500 and 4000 g. Newborns with an Apgar score of 7 or higher at 1 and 5 min were included. Umbilical cord blood samples were collected from each newborn for blood gas analysis within 60 min after birth. RESULT: The study included 340 neonates, with 170 born via caesarean section and 170 born through vaginal delivery. No significant differences were observed in Apgar scores between two groups. ABG analysis showed that vaginally born neonates had lower pH (7.24 ± 0.08 vs. 7.27 ± 0.07, P < 0.001), PCO2 (P = 0.015), and HCO3 (P < 0.001). Cesarean section neonates had higher oxygen saturation (P = 0.007) and pressure of oxygen (P < 0.001), and less negative base excess (P < 0.001). In the subgroup analysis, neonates whose mothers received epidural anesthesia had lower pH (7.23 ± 0.07 vs. 7.25 ± 0.08, P = 0.021) and more negative base excess (P = 0.026). Other parameters of ABG did not differ significantly between the groups (P > 0.05). CONCLUSION: It has been proven that the mode of delivery, whether it is vaginal or cesarean, as well as the administration of epidural anesthesia during vaginal delivery, have a significant impact on newborns at birth. Newborns delivered vaginally exhibit metabolic acidosis compared to those delivered via cesarean section. Although these differences are statistically significant, they do not have a notable clinical significance, as the average values of the evaluated parameters in both groups fall within the normal range.

Feasibility Analysis of ECG-Based pH Estimation for Asphyxia Detection in Neonates.

Birth asphyxia is a potential cause of death that is also associated with acute and chronic morbidities. The traditional and immediate approach for monitoring birth asphyxia (i.e., arterial blood gas analysis) is highly invasive and intermittent. Additionally, alternative noninvasive approaches such as pulse oximeters can be problematic, due to the possibility of false and erroneous measurements. Therefore, further research is needed to explore alternative noninvasive and accurate monitoring methods for asphyxiated neonates. This study aims to investigate the prominent ECG features based on pH estimation that could potentially be used to explore the noninvasive, accurate, and continuous monitoring of asphyxiated neonates. The dataset used contained 274 segments of ECG and pH values recorded simultaneously. After preprocessing the data, principal component analysis and the Pan-Tompkins algorithm were used for each segment to determine the most significant ECG cycle and to compute the ECG features. Descriptive statistics were performed to describe the main properties of the processed dataset. A Kruskal-Wallis nonparametric test was then used to analyze differences between the asphyxiated and non-asphyxiated groups. Finally, a Dunn-Sidák post hoc test was used for individual comparison among the mean ranks of all groups. The findings of this study showed that ECG features (T/QRS, T Amplitude, Tslope, Tslope/T, Tslope/|T|, HR, QT, and QTc) based on pH estimation differed significantly (p < 0.05) in asphyxiated neonates. All these key ECG features were also found to be significantly different between the two groups.

Arterial blood gas analysis or venous blood gas analysis for adult hospitalised patients with respiratory presentations: a systematic review.

BACKGROUND: Identification of hypoxaemia and hypercapnia is essential for the diagnosis and treatment of acute respiratory failure. While arterial blood gas (ABG) analysis is standard for PO2 and PCO2 measurement, venous blood gas (VBG) analysis is increasingly used as an alternative. Previous systematic reviews established that VBG reporting of PO2 and PCO2 is less accurate, but the impacts on clinical management and patient outcomes are unknown. AIMS: This study aimed to systematically review available evidence of the clinical impacts of using ABGs or VBGs and examine the arteriovenous difference in blood gas parameters. METHODS: A comprehensive search of the MEDLINE, Embase and Cochrane Library databases since inception was conducted. Included studies were prospective or cross-sectional studies comparing peripheral ABG to peripheral VBG in adult non-critical care inpatients presenting with respiratory symptoms. RESULTS: Of 15 119 articles screened, 15 were included. No studies were found that examined clinical impacts resulting from using VBG compared to ABG. Included studies focused on the agreement between ABG and VBG measurements of pH, PO2, PCO2 and HCO3 -. Due to the heterogeneity of the included studies, qualitative evidence synthesis was performed. While the arteriovenous difference in pH and HCO3 - was generally predictable, the difference in PO2 and PCO2 was more significant and less predictable. CONCLUSIONS: Our study reinforces the notion that VBG is not comparable to ABG for physiological measurements. However, a key revelation from our research is the significant lack of data regarding the clinical implications of using VBG instead of ABG, a common scenario in clinical practice. This highlights a critical knowledge gap.

Chloride and lactate as prognostic indicators of calf diarrhea from eighty-nine cases.

IMPORTANCE: Deaths due to neonatal calf diarrhea are still one of the most critical problems of cattle breeding worldwide. Determining the parameters that can predict diarrhea-related deaths in calves is especially important in terms of prognosis and treatment strategies for the disease. OBJECTIVE: The primary purpose of this study was to determine mortality rates and durations, survival status, and predictive prognosis parameters based on vital signs, hematology, and blood gas analyses in neonatal diarrheic calves. METHODS: The hospital automation system retrospectively obtained data from 89 neonatal diarrheic calves. RESULTS: It was found that 42.7% (38/89) of the calves brought with the complaint of diarrhea died during hospitalization or after discharge. Short-term and long-term fatalities were a median of 9.25 hours and a median of 51.50 hours, respectively. When the data obtained from this study is evaluated, body temperature (°C), pH, base excess (mmol/L), and sodium bicarbonate (mmol/L) parameters were found to be lower, and hemoglobin (g/dL), hematocrit (%), lactate (mmol/L), chloride (mmol/L), sodium (mmol/L) and anion gap (mmol/L) parameters were found to be higher in dead calves compared to survivors. Accordingly, hypothermia, metabolic acidosis, and dehydration findings were seen as clinical conditions that should be considered. Logistic regression analysis showed that lactate (odds ratio, 1.429) and CI- (odds ratio, 1.232) concentration were significant risk factors associated with death in calves with diarrhea. CONCLUSIONS AND RELEVANCE: According to the findings obtained from this study, the determination of lactate and Cl- levels can be used as an adjunctive supplementary test in distinguishing calves with diarrhea with a good prognosis.