Arterial Blood Gas Research Articles

Efficacy of acupuncture as adjunctive therapy for patients with acute exacerbation of chronic obstructive pulmonary disease: a systematic review and meta-analysis

BackgroundChronic obstructive pulmonary disease (COPD) is a highly prevalent and potentially fatal respiratory condition. Acute exacerbations can accelerate lung function decline and increase mortality. Acupuncture has been increasingly used as an adjunctive treatment for respiratory diseases, but its effectiveness in acute exacerbations of COPD (AECOPD) remains controversial. Existing evaluations on this topic are limited in scope and depth. This study aimed to provide a more comprehensive review to evaluate the effectiveness of acupuncture as an adjuvant treatment for acute exacerbations of chronic obstructive pulmonary disease.Study designSystematic review and meta-analysis of existing randomized controlled trials on acupuncture-assisted treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD).MethodsWe included randomized controlled trials (RCTs) comparing acupuncture combined with conventional Western medicine to conventional Western medicine alone in patients with acute exacerbations of COPD (AECOPD). Our literature search covered ten databases, including PubMed and Web of Science ect., up until March 2025. The primary outcome was the effective rate, while secondary outcomes included lung function (FEV1%, FEV1/FVC%, FEV1), arterial blood gas analysis (PaO2, PaCO2, SaO2), the 6-min walk test (6MWT), COPD Assessment Test (CAT), modified Medical Research Council (mMRC) scale, and success rate of weaning. Data were extracted from eligible studies, and statistical analysis was performed using RevMan 5.3 and Stata 16.0. Risk of bias and evidence quality were assessed using Cochrane tools and GRADE methodology.ResultsThe study included 31 randomized controlled trials (RCTs) with 2,299 participants. The studies were primarily conducted in hospital inpatient departments, and the typical treatment duration ranged from 1 to 2 weeks. Compared with conventional Western medicine alone, acupuncture combined with conventional Western medicine showed greater effectiveness (RR = 1.23, 95%CI 1.17 ~ 1.29, p < 0.001). Acupuncture significantly improved lung function (FEV1%: MD = 5.67, 95%CI 2.97 ~ 8.37, p < 0.001; FEV1/FVC: MD = 4.44, 95%CI 1.86 ~ 7.03, p < 0.001; FEV1: MD = 0.37, 95%CI 0.26 ~ 0.47, p < 0.001), reduced hypoxia (PaO2: MD = 3.60, 95%CI 2.23 ~ 4.98, p < 0.001; PaCO2: MD = -3.30, 95%CI -5.80 ~ −0.80, p < 0.05; SaO2: MD = 4.23, 95%CI 3.02 ~ 5.43, p < 0.001), and improved exercise tolerance (6MWT: MD = 40.34, 95%CI 30.50 ~ 50.17, p < 0.001), quality of life (CAT: MD = -2.68, 95%CI -3.39 ~ −1.96, p < 0.001), and dyspnea (mMRC: MD = -0.33, 95%CI -0.47 ~ −0.20, p < 0.001). However, the weaning success rate did not show a statistically significant difference between the two groups (RR = 1.18, 95%CI 0.95 ~ 1.48, p = 0.14). Mild side effects were reported in some studies. We rated the quality of evidence as very low to medium.ConclusionThis systematic review and meta-analysis demonstrate that acupuncture, as an adjunctive treatment for acute exacerbations of chronic obstructive pulmonary disease, improves clinical efficacy and key outcomes. Our findings are consistent with previous studies that demonstrated improvements in the COPD Assessment Test (CAT) and arterial blood gas parameters (PaO2 and PaCO2). Unlike previous meta-analyses, the present study showed that adjunctive acupuncture significantly improved patient lung function FEV1% outcomes and significantly improved patient 6-min walk distance and modified Medical Research Council (mMRC) score; however, there was no significant difference in the success rate of weaning between the two groups. Although the review highlights clinical benefits, the heterogeneity of the included studies and the overall quality of the evidence suggest that more high-quality randomized controlled trials are needed to validate these findings and optimize treatment strategies. These studies should also prioritize standardizing acupuncture regimens, extending treatment duration, and conducting long-term follow-up assessments.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/ ID:CRD42024528155.

Delayed emergence after general anesthesia: working through the differential diagnosis

Introduction and importance: Delayed emergence (DE) following general anesthesia is a critical postoperative complication characterized by the patient’s inability to regain an appropriate level of consciousness 30–60 minutes after surgery. Rapid identification and management of potential causes, including metabolic disturbances and pharmacologic effects, are essential to prevent adverse outcomes. Case presentation: We present the case of a 67-year-old female with multiple comorbidities, including chronic obstructive pulmonary disease, hemochromatosis, and hypothyroidism, who underwent emergent exploratory laparoscopy for a pelvic abscess. Despite uneventful hemodynamic stability and appropriate anesthetic management, the patient experienced delayed emergence. Initial interventions included reversal agents for neuromuscular blockade and opioids; however, the patient’s mental status continued to fluctuate. Arterial blood gas analysis revealed hypercapnic respiratory metabolic acidosis, prompting ventilatory support and subsequent reintubation. Neurovascular events were ruled out with unremarkable imaging findings. Clinical discussion: Delayed emergence can result from a variety of etiologies, including residual anesthetic effects, metabolic imbalances, and neurologic events. This case highlights the importance of prompt identification of hypercapnic respiratory metabolic acidosis as a reversible cause of DE. Management included ventilatory support with bilevel positive airway pressure and subsequent intubation, which resolved the acidosis and restored consciousness. Conclusion: This case underscores the need for a systematic approach in the differential diagnosis of delayed emergence. Timely recognition and management of hypercapnic respiratory metabolic acidosis through ventilatory support were crucial in preventing further complications.

Reference values of arterial blood gas index in adult respiratory failure in high altitude area

The arterial blood gas (ABG) reference values determined at or near sea level may not be applicable in high-altitude areas. This study investigated the reference values of the ABG indexes for adult respiratory failure in the Tibetan Autonomous Prefecture in Yunnan Province, China. This prospective study enrolled adult patients with respiratory failure at the internal medicine department of Diqing Tibetan Autonomous Prefecture (altitude: 3294 m) in Yunnan province between November 2019 and March 2022. There were 112 cases of type I respiratory failure (median age of 56 years, 61 males) and 91 with type II respiratory failure (median age of 59 years, 42 males). The reference value of PaO2 for type I respiratory failure was 46.9 mmHg (AUC 1.000, 95% CI 1.000–1.000, sensitivity and specificity of 100%, P < 0.001). The reference value of PaCO2 for type II respiratory failure was 38.1 mmHg (AUC 0.871, 95% CI 0.823–0.920, sensitivity and specificity of 95.6% and 60.4%, respectively, P < 0.001). It might be recommended that the reference values of PaO2 and PaCO2 for type I and II respiratory failure be 46.9 and 38.1 mmHg, respectively, in high-altitude areas.

Prevalence and consequences of patient-ventilator interactions in a cohort of home ventilated restrictive and neuromuscular patients. A multicenter study

QuestionAnalysis of patient-ventilator interactions in patients on chronic home mechanical ventilation can be time consuming, and the consequences of individual interaction on pulmonary gas exchange are not well understood. The objective was to analyze the relationship between interactions and nocturnal oxymetry and arterial blood gases.MethodsCross-sectional study in restrictive and neuromuscular patients who underwent respiratory polygraphy with a system that allowed interactions to be correlated with mean saturation in 5-minute periods. Unintentional leaks, periodic decreases in flow and primary patient-ventilator asynchronies were analyzed. Each interaction was correlated with mean SpO2and baseline arterial blood gases obtained at the recruitment visit, and the 5-minute SpO2analysis was individualized for each patient based on their mean SpO2andsdduring polygraphy.ResultsForty patients were included. There was a correlation between interactions and mean SpO2in periods with mean accidental leak greater than 20 L·min−1(ANOVA test). After exclusion of periods with leakage above this threshold, a relationship was documented between periodic decreases in flow and asynchronies with mean SpO2in 5-minute periods. However, there was no relationship between PVI and baseline arterial blood gases at recruitment.Answer to the questionThe presence of interactions was associated with a decrease in mean SpO2when 5-minute recordings are analyzed. Therefore, it seems advisable to systematically detect and correct patient-ventilator interactions in home mechanical ventilated patients.

Primary Sjӧgren’s Syndrome Unveiling Type 1 Renal Tubular Acidosis: A Rare Case Report of Hypokalemic Periodic Paralysis from a Developing Country

Primary Sjogren syndrome is a systemic autoimmune disorder commonly presenting with dryness involving the eyes and mouth due to inflammation and resultant pathology of the lacrimal and salivary glands. Sjogren syndrome is managed by replacing moisture at affected glandular sites and diminishing the autoimmune response locally as well as systemically. This case illustrates the life threatening consequences, such as hypokalemic periodic paralysis in a 56 year old woman in whom the discovery of type 1 distal Renal Tubular Acidosis (RTA) led to the diagnosis of primary Sjӧgren’s syndrome (SS) and its further management. HPP is a rare disorder caused by skeletal muscle ion channel mutations, mainly affecting calcium or sodium channels. HPP causes include genetic mutations, familial vs acquired cause due to hyperthyroidism, and certain triggers include strenuous exercise, high carbohydrate meal, stress, cold temperature, etc. She experienced bilateral lower limb weakness, along with progressive upper limb and neck muscle weakness over a week. Laboratory tests (alkaline urine pH and bicarbonate drop) and arterial blood gas (ABG) indicating RTA with hypokalemia raised clinical suspicion of Sjӧgren’s syndrome. Further investigations revealed a positive Schirmer’s test and Immunologic workup showed a strongly positive ANA, with positive antibodies to SSA and SSB thereby confirming primary Sjӧgren’ssyndrome. The case underscores the idea that acute hypokalemia from unrecognised renal tubular acidosis (RTA) may unmask Sjӧgren’s syndrome in patients with sicca complaints and other renal involvements.

Acid–Base Status in Critically Ill Patients: Physicochemical vs. Traditional Approach

Background/Objectives: Critically ill patients can often present acid–base alterations. The aim of this study was to evaluate the prevalence and the time-course of acid–base alterations on intensive care unit (ICU) admission and on day one by the traditional standard base excess (SBE)-based and the Stewart methods in mechanically ventilated patients. Methods: A prospective observational study enrolling mechanically ventilated patients in the ICU was conducted. Arterial blood gas analysis, blood and urine samples were obtained on ICU admission and on day one. Plasmatic and urinary acid–base variables were compared among acidemic, alkalemic and patients with normal pH. The agreement between the SBE-based and Stewart methods was assessed at ICU admission and on day one. Results: One hundred and seventy-two patients were enrolled. On ICU admission, 55 (32%), 29 (17%) and 88 (51%) patients had acidemia, alkalemia and a normal pH, respectively. On day one, 12 (7%), 48 (28%) and 112 (65%) patients had acidemia, alkalemia and a normal pH with lower values of paCO2 and albumin. According to the SBE and Stewart approaches, the occurrence of metabolic acidosis was similar (24% vs. 35%), as well as the rate of metabolic alkalosis (16% vs. 23%) on ICU admission; on day one, the occurrence of metabolic acidosis was different (12% vs. 35%), as well as the rate of metabolic alkalosis (35% vs. 14%). The agreement between methods was estimated to be low both on ICU admission and on day one. Conclusions: Up to 50 % of mechanically ventilated patients presented acid–base derangements, mainly due to acidemia on ICU admission and to alkalemia after 24 h, secondary to alterations in carbon dioxide and plasma albumin. The agreement between the traditional and Stewart approaches was poor. The Stewart approach could be more accurate in detecting the acid–base disturbances in critically ill patients characterized by changes of mechanical ventilation and fluid administration.

Red blood cell (RBC) arteriovenous gap as a marker of hemotransfusion in massive and fulminant hemorrhage with the formation of Multiple Organ Dysfunction Syndrome (MODS). Case report

Background: Massive and fulminant hemorrhage frequently leads to critical states such as hemorrhagic shock and Multiple Organ Dysfunction Syndrome (MODS). Early diagnostic and therapeutic decision-making, particularly regarding hemotransfusion, remains a challenge when classical venous indicators do not reflect the severity of hypoxia. This study proposes the arteriovenous red blood cell (RBC) gap and pCO₂ arteriovenous (AV) gap as novel biomarkers for evaluating tissue hypoxia and guiding red blood cell transfusion, especially in cases with visual blood loss exceeding 3 liters. Materials and Methods: This case-based investigation evaluated the diagnostic utility of the RBC arteriovenous gap and the pCO₂ AV gap (&gt;6 mmHg) as markers of Microcirculatory-Mitochondrial Distress Syndrome (MMDS), a precursor of MODS. Analysis included sequential arterial and venous blood gas measurements, lactate monitoring, and oxygenation indices in a patient presenting with severe hemorrhage and signs of MODS. The microcirculatory-mitochondrial recruitment strategy was applied, involving volemic resuscitation, oxygenation correction, and targeted hemotransfusion. Results: Initial measurements revealed a pCO₂ AV gap of 49.7 mmHg, confirming severe tissue hypoxia and MMDS. This gap decreased to 10.2 mmHg following the recruitment strategy, coinciding with the normalization of pH (6.9 → 7.4), improved oxygenation (SO₂ 51% → 98%), and decreased lactate levels (8.2 → 1.8 mmol/L). Despite a normal venous hematocrit (VHct 36%) and hemoglobin (VtHb 12.3 g/dL), arterial samples showed critical reductions (AHct &lt;12%), justifying RBC transfusion. This AV discrepancy provided a reliable medico-legal basis for intervention, which traditional venous markers alone would not have supported. Conclusion: The RBC and pCO₂ AV gaps are effective, underutilized markers for detecting MMDS and guiding hemotransfusion in cases of massive hemorrhage. They reflect systemic hypoxia more accurately than isolated venous parameters. The application of microcirculatory-mitochondrial recruitment strategies improves patient outcomes and supports metabolic recovery, offering a low-tech yet life-saving intervention approach. These findings propose a paradigm shift in intensive care resuscitation strategies and transfusion criteria in critical care.

High Flow, High-Pressure Retrograde Cerebral Perfusion at 28°C is Safe and Effective for Hemiarch Replacement of the Ascending Aorta.

Traditional retrograde cerebral perfusion (RCP) parameters may be suboptimal for washout of debris during hemiarch replacement of the ascending aorta, so we have designed a protocol of increased RCP pressure and flow at moderate hypothermia. We hypothesize that higher RCP pressure is safe in neurological outcomes in cases utilizing circulatory arrest at 28°C in elective hemiarch replacement.A retrospective review of a single-institution prospective database was used to search for all patients with elective hemiarch surgery from 2015 to 2022. Two cohorts were created-patients who received RCP only during circulatory arrest at 28°C and patients who received selective antegrade cerebral perfusion (SACP) during circulatory arrest. Neurological and postoperative outcomes were compared. Arterial blood gas measurements during RCP were taken from the left carotid of 34 patients, which were compared with the arterial blood gas from the bypass circuit to ensure adequate oxygen extraction. Propensity score matching was used to adjust for perioperative indices and patient characteristics.A total of 248 patients were in the SACP cohort and 79 patients in the RCP cohort. The two groups were similar based on patient demographics and relevant comorbidities. The cohorts differed in nadir bladder temperature, circulatory arrest time, and cardiopulmonary bypass time. After propensity matching, nadir bladder temperature, circulatory arrest, and cardiopulmonary bypass times were similar. Neurological postoperative outcomes were similar in the unmatched and matched analysis. The median pressure in the RCP group during circulatory arrest was 40 mm Hg. The median change in oxygen from bypass circuit to the carotids is 398 mm Hg with a mean oxygen extraction of 93.3%.These data demonstrate that a more aggressive approach to RCP beyond traditional constraints at 28°C is safe for short periods of circulatory arrest. Even with the new RCP parameters and after adjusting for standard patient and perioperative characteristics, there is no difference between SACP and RCP in neurological outcomes. Further, adequate oxygen extraction is achieved during RCP.

Hyperglycemia in the diabetic range, but not previous diagnosis of diabetes mellitus, is an independent indicator of poor outcome in patients hospitalized for severe COVID-19.

Diabetes mellitus (DM) and hyperglycemia are associated with poor outcome(s) in COVID-19 hospitalized patients, but their independent impact on prognosis remains unclear. We aimed to assess the impact of DM and hyperglycemia on COVID-19 outcomes. Clinical data/records from COVID-19 patients admitted to the Parma University-Hospital (February 23rd to March 31st, 2020) were retrieved and analysed (NCT04550403). Fasting plasma glucose (FPG), inflammatory markers and the main biochemical variables were collected at admission. Patients underwent chest high-resolution CT and arterial blood gas analysis to determine the PaO2/FiO2 ratio (P/F ratio). The primary outcome was a composite of intensive care unit admission and/or death. Among 756 subjects, 143 (19%) had DM. These patients were older with higher comorbidity rates. The primary outcome occurred in 61.5% DM patients versus 43.4% without DM (p < 0.001). In multivariable analysis (accuracy UC = 0.93), older age, cardiovascular and kidney diseases, FPG ≥ 126mg/dl, C-reactive protein, and P/F ratio, but not previous DM, were independent risk indicators. DM indicated poor COVID-19 outcomes, but not when adjusted for other clinical variables/comorbities, suggesting that its impact was mostly driven by concomitant factors. The independent role of fasting hyperglycemia points to the need for further research on its contribution to COVID-19.

Comparison of arterial and venous blood gases in patients with COPD (Chronic Obstructive Pulmonary Disease) and CLD (Chronic Liver Disease).

Objective: To Determine Correlation between mean Venous and Arterial Blood Gases in patients with COPD and CLD. Study Design: Cross Sectional Descriptive study. Setting: Department of Internal Medicine (MW6) and Accident and Emergency Department of PIMS, Islamabad. Period: 3rd September 2021 to 3rd March 2022. Methods: The study included 110 patients with COPD and CLD who were hospitalized to MW6 and the Emergency Department. The correlation sample size calculator was used to determine the sample size. Consecutive Non-Probability Sampling was the method used to choose samples. Patients with COPD and CLD who were older than thirty years, regardless of gender, were included in the study; however, patients with other metabolic disorders, such as diabetic ketoacidosis, lactic acidosis, a history of poisoning, etc., were not. Results: The average age of patients was 66.3 + 13.6 years and male were 79 (71.8%). Samples were taken from arteries and veins of each patient and pH was calculated. The average pH1 (arterial) level was found to be 7.41 + 0.68 mg/dl whereas the average pH2 (venous) level was 7.35 + 0.76 mg/dl in current study. Conclusion: Venous blood gas analysis cannot be used in place of arterial blood gas analysis due to the differences in pH levels. In many clinical circumstances, venous pH, PCO2, and bicarbonate cannot replace their arterial equivalents.

Congenital methaemoglobinaemia in pregnancy.

When methaemoglobin (MetHb) levels exceed 1.5% in the bloodstream, patients typically manifest cyanosis, the hallmark feature of this condition. Arterial blood takes on a dark brown hue, despite maintaining a normal partial pressure of oxygen. Suspicion of methaemoglobinaemia arises in individuals presenting with cyanosis and reduced oxygen saturation in the absence of notable cardiopulmonary symptoms. Co-oximetry with arterial blood gas is the definitive method for diagnosis, offering precise identification and quantification of MetHb levels in the blood. While acquired methaemoglobinemia has been commonly described, there are only a few reported cases of congenital methaemoglobinemia.We report a case of a pregnancy with congenital methaemoglobinaemia. A multidisciplinary team, comprising the obstetrician, physicians and haematologists, closely monitored this case. Despite her medical condition, she remained symptom-free throughout her pregnancy and underwent an uncomplicated delivery by caesarean section. We highlight the challenges in the management of such cases during the antenatal, labour, childbirth and postpartum period.

Predictive value of lung ultrasound score in weaning from mechanical ventilation in neonatal respiratory distress syndrome

BackgroundTo explore the predictive value of lung ultrasound score (LUS) in weaning from mechanical ventilation in neonatal respiratory distress syndrome (RDS).MethodsA total of 111 neonates with RDS who received mechanical ventilation in the neonatal intensive care unit (NICU) of Sichuan Provincial People’s Hospital were selected as the subjects. Before weaning, the LUS was performed by the 12-region ultrasound score of the lungs. Those neonates were divided into the weaning success group (n = 95) and weaning failure group (n = 16) according to whether they received mechanical ventilation again 48 h after weaning. Oxygenation index (OI) before weaning and arterial blood gas indexes after weaning were collected. The correlation of LUS with OI or arterial blood gas was analyzed, and the difference in LUS between the two groups was compared. The receiver operating characteristic (ROC) curve of LUS in predicting the weaning outcome of mechanical ventilation in neonatal RDS was drawn and its predictive value was verified.ResultsLUS of all neonates before weaning was significantly correlated with OI and arterial blood gas indexes, which was positively correlated with OI value (r = 0.671, p < 0.001) and arterial partial pressure of carbon dioxide (r = 0.461, p < 0.001), and negatively correlated with arterial partial pressure of oxygen (r = -0.531, p < 0.001). The LUS in the weaning success group was significantly lower than that in the weaning failure group (5(3,8) points vs. 12.5(10,16.75) points, p < 0.001). The ROC curve showed that the AUC was 0.898. The optimal cut-off value of LUS was 9.5 as the predictive value of successful weaning, with a sensitivity of 0.875 and a specificity of 0.811.ConclusionLUS is a convenient, sensitive, and accurate predictor of successful weaning of mechanical ventilation in NRDS, and can be used as an important tool for clinical guidance of weaning.

Volume-controlled inverse ratio ventilation improves safe apnea time in obese patients during the induction of general anesthesia: a randomized controlled trial

BackgroundInverse ratio ventilation theoretically increases oxygenation in obese patients. However, it is unknown whether the use of inverse ratio ventilation prolongs the safe apnea time during the induction of anesthesia. The primary objective of our study was to compare the safe apnea time between obese surgical patients receiving inverse ratio ventilation and conventional ratio ventilation during the induction of anesthesia.MethodsThis study is a prospective, randomized controlled trial. Forty obese patients who underwent elective operation under general anesthesia with endotracheal intubation were randomly allocated into the conventional ratio ventilation (CRV) group (n = 20) and inverse ratio ventilation (IRV) group (n = 20). After the patients were preoxygenated through a face mask for 3 min, anesthesia induction was performed. When the patients lost consciousness and spontaneous breathing disappeared, non-invasive positive pressure ventilation was performed for 5 min, and the inspiratory-to-expiratory (I:E) ratio was set as 1:2 in the CRV group and 2:1 in the IRV group. Heart rate, systolic blood pressure, diastolic blood pressure, and pulse oxygen saturation were recorded at four time points: (i) before pre-oxygenation (T0), (ii) pre-oxygenation for 3 min (T1), (iii) non-invasive positive pressure ventilation for 3 min (T2), and (iv) non-invasive positive pressure ventilation for 5 min (T3). Arterial blood was collected at T0, T1, and T3 for arterial blood gas analysis, and arterial oxygen partial pressure and carbon dioxide partial pressure were recorded. The patient’s expiratory oxygen fraction at T1, T2, and T3 were recorded. Peak airway pressure, plateau pressure and mean airway pressure were record at T2 and T3. The safe apnea time was recorded in both groups.ResultsForty patients completed the study. Baseline parameters were comparable between the two groups. Safe apnea time was significantly longer (210.40 ± 47.47 vs. 153.80 ± 41.54 s, mean difference [95% CI], 56.55 [28.00–85.10], p = 0.0003) and the expired O2 fraction was higher (87.60 ± 2.39 vs. 91.60 ± 1.79, mean difference [95% CI], 4.00 [2.65–5.35], p &amp;lt; 0.0001) at T3 in the IRV group compared to the CRV group.ConclusionVolume-controlled inverse ratio ventilation at an I:E ratio of 2:1, compared to conventional ratio ventilation, provided a longer safe apnea time and higher expired O2 fraction in obese patients during the induction of anesthesia.

Norepinephrine infusion for preventing hypotension during hepatic exteriorization in Kasai portoenterostomy in infants with biliary atresia: A randomized controlled trial.

Norepinephrine infusion for preventing hypotension during hepatic exteriorization in Kasai portoenterostomy in infants with biliary atresia: A randomized controlled trial.

Real-Time Reliability: Unveiling the Accuracy of Pleural Fluid Glucose Measurement with Point-of-Care Arterial Blood Gas Analyzer Technology

Real-Time Reliability: Unveiling the Accuracy of Pleural Fluid Glucose Measurement with Point-of-Care Arterial Blood Gas Analyzer Technology

Prospective Evaluation of Pulse Oximeter Accuracy Using Arterial Blood Gas Reference Measurements in Critically Ill South African Children: Preliminary Analysis

Prospective Evaluation of Pulse Oximeter Accuracy Using Arterial Blood Gas Reference Measurements in Critically Ill South African Children: Preliminary Analysis

Acid base status of the blood contained in the cardiotomy reservoir during deep hypothermic circulatory arrest at 18°C.

Background: During deep hypothermic circulatory arrest (DHCA) for pulmonary artery endarterectomy (PAE), the blood volume stored into the cardiotomy reservoir circulates through the oxygenator via the arterial shunt line where it remains oxygenated and decarboxylated. The aim of the study was to investigate the change in the acid base balance of the blood contained in the cardiotomy reservoir during DHCA. Methods: A four months retrospective analysis was conducted on patients undergoing PAE. The sweep gas inflow and the inspired fraction of O2 were kept constant throughout the duration of DHCA. Arterial blood gases were sampled at the beginning and at the end of the DHCA and were analyzed according to alpha-stat and pH-stat strategy. Results: 24 patients were included with a mean age of 59.2 (±15.7) years. The mean duration of DHCA was 15.2 (±4.1) min, and the mean sweep gas inflow was 1.4 (±0.8) L/min. Initial pH and PaCO2 were 7.31 (±0.09) and 43.2 (±9.9) mmHg, respectively, and final pH and PaCO2 were 7.51 (± 0.14); p&lt;0.001 and 23.4 (±11.9) mmHg; p&lt;0.001. There was a significant correlation between the sweep gas inflow and the post DHCA pH (r=0.797). Conclusion: The pH increases significantly during the DHCA according to the sweep gas inflow. Decreasing the sweep gas inflow between 0.5 to 1.0 L/min allows to limit the pH variation during the DHCA period.

High-frequency percussive ventilation as a lifesaving intervention in a pediatric case of life-threatening asthma: a case report and literature review.

Severe acute asthma exacerbation requiring mechanical ventilation, referred to as life-threatening asthma, presents significant challenges due to elevated airway resistance, dynamic hyperinflation, and impaired gas exchange. Conventional mechanical ventilation may be insufficient in these cases, necessitating alternative strategies. High-frequency percussive ventilation (HFPV) offers a promising approach by combining improved oxygenation and ventilation with effective secretion clearance. An 11-year-old male with a history of asthma and eczema presented to the emergency department in respiratory failure with profound hypercarbia. Life-threatening asthma with cardiopulmonary arrest led to endotracheal intubation and initiation of mechanical ventilation. Despite the use of conventional settings, oxygen saturation remained critically low, and air trapping persisted. The patient was transitioned to HFPV via a VDR®-4 ventilator. Arterial blood gases demonstrated rapid improvement within 2 hours (from pH 6.7, pCO2 >120 mmHg to pH 7.169, pCO2 77.2 mmHg). After 29 hours on HFPV, the patient was transitioned to conventional ventilation, followed by tracheal extubation to high-flow nasal cannula. The patient was discharged home within 72 hours with optimized asthma management. This case demonstrates the potential efficacy of HFPV in managing life-threatening pediatric asthma, achieving rapid stabilization without the use of neuromuscular blockade. Further prospective studies are needed to evaluate HFPV's potential as a rescue therapy in both specialized and non-specialized settings.

Value of micronutritent and NRS-2002 score in assessing nutritional status and clinical outcomes in patients with end-stage liver disease

Objective: To evaluate nutritional status and clinical outcomes in patients with end-stage liver disease by comparing and exploring the application of the Nutritional Risk Screening (NRS)-2002 score and the modified Nutrition Risk in the Critically Ill (mNUTRIC) score. Method: A retrospective cohort study method was used to screen 114 cases with end-stage liver disease admitted to the intensive care unit (ICU) of the First Hospital of Lanzhou University from December 1, 2016 to March 31, 2021 according to the inclusion and exclusion criteria. The patient's demographic data, blood routine, blood biochemical indexes, coagulation function indexes, arterial blood gas analysis and imaging examination data were collected. The mNUTRIC score, NRS-2002 score, sequential organ failure (SOFA) score, model for end-stage liver disease (MELD) score, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score, Child-Pugh grade, and clinical outcomes at 28 and 90 days after entering the ICU for 24 hours were collected. The differences in clinical indicators between the mNUTRIC high group (≥5 points) and the low group, and the NRS-2002 high group (≥3 points) and the low group were compared. Spearman correlation analysis was used to explore the correlation between the mNUTRIC score and NRS-2002 score, clinical indicators, and 28 and 90-day mortality rates. Multivariate logistic regression was used to analyze the related factors of death at 28 and 90 days. The value of mNUTRIC score and NRS-2002 score in assessing the clinical outcomes of patients with end-stage liver disease was explored by receiver operating characteristic (ROC) curve. Results: The clinical indicators related to nutritional status of patients were worse in the high-mNUTRIC group than those in the low-mNUTRIC group, and the 28-day and 90-day mortality rates were significantly higher than those in the low-mNUTRIC group [89.0%(65/73) vs 29.2%(12/41), 97.2%(71/73) vs 39.0%(16/41), P<0.001]. There was no statistically significant difference in the incidence rate of hepatic encephalopathy, esophageal variceal bleeding, and ascites between the high and low mNUTRIC group. The clinical indicators related to nutritional status were worse in the high-NRS-2002 group than those in the low-NRS-2002 group of patients, and the 28-day and 90-day mortality rates were significantly higher than those in the low-group [73.0%(73/100) vs 4/14, 81.0%(81/100) vs 6/14, P=0.008, 0.004]. There was no statistically significant difference in the incidence rate of hepatic encephalopathy, esophageal variceal bleeding, and ascites between the high and the low group. Patient's age, white blood cell count (WBC), urea nitrogen (BUN), creatinine (UREA), uric acid (UA), total cholesterol (TG), Child-Pugh, MELD, SOFA, APACHE Ⅱscores were significantly positively correlated with the mNUTRIC score. Conversely, albumin (Alb) and Glasgow Coma Scale (GCS) were significantly negatively correlated. Patient's age, WBC, CREA, BUN, UREA, UA, Child-Pugh, MELD, SOFA, APACHE Ⅱwere significantly positively correlated with the NRS-2002 score.Conversely, albumin (Alb) and Glasgow Coma Scale (GCS) were significantly negatively correlated (P<0.05). The 28-day and 90-day mortality rates of patients increased with the increase in the mNUTRIC scores. The mNUTRIC score was an independent predictor of death within 28 and 90 days in patients with end-stage liver disease. The area under the curve (AUC) of mNUTRIC for predicting patient death at 28 days was 0.864 (95%CI: 0.794-0.934). The AUC of NRS-2002 for predicting patient death at 28 days was 0.683 (95%CI: 0.573-0.792). The AUC of the two indicators combined for predicting patient death at 28 days was 0.868 (95%CI: 0.799-0.936). The AUC of mNUTRIC for predicting patient death at 90 days was 0.915 (95%CI: 0.861-0.969). The AUC of NRS-2002 for predicting patient death at 90 days was 0.715 (95%CI: 0.599-0.832). The AUC of the two indicators combined for predicting patient death at 90 days was 0.922 (95%CI: 0.871-0.972). Conclusion: mNUTRIC score and NRS-2002 score can better evaluate the nutritional status in patients with end-stage liver disease. The mNUTRIC score is a good predictor of 28-day and 90-day mortality in patients with end-stage liver disease, and its application value efficacy is enhanced when combined with NRS-2002.

A modified rat model of 8 minutes asphyxial cardiac arrest and cardiopulmonary resuscitation.

The animal model of cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) serves as a crucial tool for investigating the pathophysiology and treatment strategies associated with cardiac arrest, however, standardized procedures for such models remain insufficiently established. We aimed to modify and specify the existing rat model of asphyxial CA and CPR while providing an analysis of long-term outcomes.A total of 46 rats were allocated into two groups,sham and CA group.In CA group, cardiac arrest was induced through 8 minutes of hypoxia prior to the administration of CPR. In sham group, only tracheal intubation and vascular catheterization were conducted under isoflurane anesthesia. Key parameters along with arterial blood gas results during modeling were meticulously recorded. After a 2-week postoperative observation period, the survival rate of rats and neurobehavioral changes on days 1, 3, 7, and 14 following resuscitation were assessed. Two weeks later, a pathological examination of brain tissue was conducted to evaluate neuronal damage. Results indicated that the average duration of cardiac arrest in CA group was 292.9 ± 12.5 seconds, with a return of spontaneous circulation rate of 78.95% and a survival rate at day 14 reaching 32%. After a duration of 2 weeks, the neurobehavioral scores of the surviving rats returned to their initial baseline levels; however, pathological examination revealed evidence of neuronal damage. In conclusion, we present a refined protocol for establishing a stable rat model of asphyxial CA and CPR, which may assist researchers in this field in enhancing the success rate of modeling.