Arterial Blood Gas Research Articles

Association Between Early Hyperoxemia Exposure and Intensive Care Unit Mortality in Intracerebral Hemorrhage: An Observational Cohort Analysis.

Supraphysiologic levels of oxygen could have potential adverse effects on the brain that may be dose and time dependent in patients with brain injury. We therefore aimed to assess whether exposure to excess supplemental oxygen, measured as time-weighted mean exposure to hyperoxemia, was associated with intensive care unit (ICU) mortality in patients with intracerebral hemorrhage (ICH). In this single-center retrospective cohort study, we included all patients admitted to our ICU with a diagnosis of primary spontaneous ICH. To provide a longitudinal measure of hyperoxemia exposure, we calculated the hyperoxemia dose, defined as the area under the partial pressure of oxygen in arterial blood (PaO2) time curve above the threshold PaO2 value of 100mm Hg (13.3kPa) divided by the number of hours of potential exposure. To provide consistent potential exposure windows and limit bias from informative censoring, nested subsets were created with progressively longer exposure periods (0-1day, 0-2days, 0-3days, 0-4days, 0-5days, 0-6days, 0-7days). We used multivariable Cox regression, with hyperoxemia dose as a time-dependent covariate, to model ICU mortality. Admission ICH and Acute Physiology and Chronic Health Evaluation II scores were included as predictor covariables. A step-function extended Cox model was also fitted. Between September 2019 and July 2022, 275 patients met the inclusion criteria, with 24,588 arterial blood gas results available for analysis. The mean age was 57.19years (± 13.99), 59.64% were male, 23.64% had an infratentorial origin of hemorrhage, and ICU mortality was 35.64%. Almost all patients (97.45%) were exposed to hyperoxemia during their ICU admission. Cox regression modeling showed an association between hyperoxemia dose and ICU mortality (hazard ratio 1.15, confidence interval 1.05-1.25, p = 0.003). This association was observed in the 0-1day subset in the step-function extended Cox model (hazard ratio 1.19, confidence interval 1.06-1.35, p = 0.005) but not in any of the subsequent exposure periods. In patients with ICH admitted to the ICU, we observed an association between hyperoxemia dose and ICU mortality. Further prospective study is required to inform guidance on early systemic oxygen targets in ICH.

Comparison of cardiopulmonary effects of propofol, ketamine–propofol and isoflurane anesthesia in the domestic chicken (Gallus gallus domesticus)

ObjectiveTo compare the effects of propofol, ketamine–propofol and isoflurane, at similar anesthetic depth, on cardiopulmonary variables in unpremedictated chickens. Study designProspective, randomized, crossover experimental trial. AnimalsA total of 10 male Leghorn domestic chickens, aged 3 months and body mass 1.4–2.0 kg. MethodsBirds were randomly assigned to each of three anesthetic protocols, 7 days apart: intravenous propofol, intravenous ketamine–propofol or isoflurane. Anesthesia was induced (indicated by loss of righting reflex and tracheal intubation) and maintained with propofol (10 mg kg–1 minute–1, then 1.1 mg kg–1 minute–1), ketamine–propofol (5 mg mL–1 ketamine and 5 mg mL–1 propofol combined; 10 mg kg–1 minute–1, then 1.1 mg kg–1 minute–1) or isoflurane [5% vaporizer setting initially, then end-tidal concentration (Fe′Iso) of 2%] for 65 minutes. Anesthesia was maintained at a similar anesthetic depth based upon positive or negative responses to toe pinch. Heart rate (HR), respiratory rate (fR), noninvasive arterial blood pressure and arterial blood gases were measured during anesthesia. Propofol or ketamine–propofol infusion rates and Fe′Iso required to prevent movement in response to a noxious stimulus and recovery times were recorded. ResultsAnesthesia induction dose was 9.0 ± 0.8 (mean ± SD) and 12.2 ± 0.3 mg kg–1 for propofol and ketamine–propofol, respectively. Propofol and ketamine–propofol infusion rates and Fe′Iso required to prevent movement in response to the noxious stimulus were 0.88 ± 0.14 mg kg–1 minute–1, 0.92 ± 0.14 mg kg–1 minute–1 and 1.45 ± 0.28%, respectively. Cardiopulmonary variables remained clinically acceptable, but ketamine–propofol was associated with a significantly higher HR (p = 0.0001) and lower fR (p = 0.0001). Time to extubation did not differ among treatments. Conclusions and clinical relevanceCardiovascular and respiratory variables were maintained within normal ranges in all treatments. Coadministration of ketamine with propofol significantly reduced the induction and maintenance dose of propofol.

Evaluation of the predictors and frequency of silent hypoxemia in COVID-19 patients and the gap between pulse oximeter and arterial blood gas levels: A cross-sectional study.

Silent hypoxemia is when patients do not experience breathing difficulty in the presence of alarmingly low O2 saturation. It could cause rapid deterioration and higher mortality rates among patients, so prompt detection and identifying predictive factors could result in significantly better outcomes. This study aims to document the evidence of silent hypoxemia in patients with COVID-19 and its clinical features. A total of 78 hospitalized, nonintubated patients with confirmed COVID-19 infection were included in this study. Their O2 saturation was measured with a pulse oximeter (PO), and arterial blood gas (ABG) was taken. Demographic and clinical features were recorded. The Borg scale was used to evaluate dyspnea status, and patients with a score of less than two accompanied by O2 saturation of less than 94% were labeled as silent hypoxic. Univariate analysis was utilized to evaluate the correlation between variables and their odds ratio (OR) and 95% confidence interval (CI). Silent hypoxemia was observed in 20 (25.6%) of the participants. The average difference between the PO and ABG methods was 4.36 ± 3.43. Based on regression analysis, dyspnea and respiratory rate demonstrated a statistically significant correlation with the O2 saturation difference between PO and ABG (OR: 2.05; p = 0.026; 95% CI: 0.248-3.847 and OR: 0.144; p = 0.048, 95% CI: 0.001-0.286). Furthermore, the Borg scale (OR: 0.29; p = 0.009; 95% CI: 0.116-0.740) had a significant reverse correlation with silent hypoxia. Silent hypoxemia can be a possible complication that affects some COVID-19 patients. Further care should be bestowed upon the younger population and those with underlying neurological or mental illnesses. Furthermore, the respiratory rate, pulse oximeter, and arterial blood gas O2 levels should be considered alongside each other.

Effects of NF-κB Inhibitor on Sepsis Depend on the Severity and Phase of the Animal Sepsis Model.

Hyperinflammation occurs in sepsis, especially in the early phase, and it could have both positive and negative effects on sepsis. Previously, we showed that a new concept of NF-κB inhibitor, exosome-based super-repressor IκBα (Exo-srIκB) delivery, has a beneficial effect on sepsis. Here, we further investigate the therapeutic effects of Exo-srIκB at different severities and phases of sepsis using an animal polymicrobial intra-abdominal infection model. We used a rat model of fecal slurry polymicrobial sepsis. First, we determined the survival effects of Exo-srIκB on sepsis according to the severity. We used two different severities of the animal sepsis model. The severe model had a mortality rate of over 50%. The mild/moderate model had a less than 30% mortality rate. Second, we administered the Exo-srIκB at various time points (1 h, 6 h, and 24 h after fecal slurry administration) to determine the therapeutic effect of Exo-srIκB at different phases of sepsis. Lastly, we determined the effects of the Exo-srIκB on cytokine production, arterial blood gas, electrolyte, and lactate. The survival gain was statistically significant in the severe sepsis model when Exo-srIκB was administered 6 h after sepsis. Interleukin 6 and interleukin-10 were significantly decreased in the kidney when administered with Exo-srIκB. The laboratory data showed that lactate, glucose, and potassium levels were significantly lowered in the NF-κB inhibitor group. In conclusion, Exo-srIκB exhibited a beneficial therapeutic effect when administered 6 h post fecal slurry administration in a severe sepsis model.

Study on comparison of electrolytes in hospitalized patients of critical care medicine by automated biochemistry analyzer and arterial blood gas analyzer

Critical care medicine department has to assess electrolytes accurately and quickly to initiate the treatment. Blood samples are analyzed in a matter of seconds by arterial blood gas analyzers (ABG), albeit their accuracy is still up for debate. The current study objectives were to estimate and compare the levels of electrolytes (sodium, potassium, and chloride) in hospitalized critical care patients as determined by automated biochemistry analysis and blood gas analyzer and to assess the degree of agreement between the two instruments and obtain information on whether these values can be interchanged. A prospective hospital based observational study was undertaken after obtaining institutional ethical committee clearance. The study included a total of 195 paired venous and arterial samples from the patients admitted to Critical Care Medicine Unit of NIMS Hospital, Jaipur, India in whom electrolytes were analysed on Arterial Blood Gas (ABG) analyzer and Automated Biochemistry Analyzer (ABA). Analysis was done on ABL555 blood gas analyzer located in the critical care medicine unit and vitros 5600, located in Clinical Biochemistry. Statistical analysis was done using Student’s t test and Pearson’s correlation coefficient test.A total of 195 samples were analyzed. The mean levels of sodium, potassium and chloride were 136.64 ± 5.44 mmol/L, 3.87 ± 0.523 mmol/L and 100.79 ± 6.65 mmol/L respectively analyzed by ABG analyzer. The mean levels of sodium, potassium and chloride were 136.65 ± 5.81mmol/L, 88 ± 0.543 mmol/L and 100.47 ± 6.41 mmol/L respectively analyzed by ABA. Student’s t test comparison p values for sodium, potassium and chloride were 0.458 (Not Significant), 0.1867 (Not Significant) and 0.0438 (Significant) between the two instruments. The strength of agreement between the two instruments for sodium, potassium and chloride were analyzed using pearsons correlation coefficient. There was strong agreement for all the three parameters between the two instruments and the p value was 0.00001 (highly significant) for all the three parameters.The results of this investigation showed no discernible differences between the automated biochemistry analyzer and arterial blood gas analyzer measurements of sodium, potassium, and chloride. Clinicians can make critically important decisions by relying on the results of arterial blood gas analysis.

Assessment of the Efficacy of an Automated AMBU Bag Operating Device (RC Device) in Patients Requiring Mechanical Ventilation: A Pilot Study

Abstract Background Providing efficient mechanical ventilation using artificial manual breathing unit is a tiring and laborious task for healthcare providers. The current pilot study was planned to assess the efficacy of an automated artificial mechanical breathing unit (respiration control [RC] device) in patients requiring mechanical ventilation in a tertiary care hospital in North India. RC device is an automated bag valve mask ventilator developed in collaboration with Gyrodrive Machineries (P) Ltd. India and Postgraduate Institute of Medical Education and Research, Chandigarh. Materials and Methods Ten adult patients from the emergency and trauma section requiring mechanical ventilation who were unable to obtain ventilators in the intensive care unit were enrolled in the study. The vital parameters of the patients and the respiratory parameters from arterial blood gas were recorded at given time periods. Results All 10 patients recruited in the study were ventilated using the RC device for at least 24 hours. The mean age of the patients was 32.3 ± 4.3 years. The mean Glasgow coma scale was 7.2 ± 2.0 (range: 3–10). The heart rate, systolic blood pressure, and diastolic blood pressure remained within normal limits. There were no episodes of desaturation in any of the patients. The patients' care provider rated their satisfaction with the device as excellent in two patients and good in eight patients. Conclusion RC device has shown a promising result in providing satisfactory care among trauma patients and may be used in providing routine mechanical ventilation among these patients.

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

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. 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 1and 5min were included. Umbilical cord blood samples were collected from each newborn for blood gas analysis within 60 min after birth. 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). 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.

Optimising operating theatre (OT) efficiency while maintaining the standardised patient care in adolescent idiopathic scoliosis (AIS) surgery with the dedicated spine team approach: a specialised spine unit experience.

To report the efficiency of OT utilisation and perioperative outcomes with a dedicated spine team approach in AIS patients who underwent posterior spinal fusion (PSF) surgeries in a consecutive case operation list. Three AIS patients operated in a day (8:00AM-8:00PM) by a dedicated spine team were recruited between 2021 and 2022. The dedicated team comprised of three senior spine consultants who operated using a dual attending surgeon strategy, an anaesthetic consultant, dedicated surgical scrub nurses, anaesthesiology nurses, radiographers, and neuromonitoring technicians. Patients were categorised according to the sequence of operation list of the day (Case 1, Case 2, and Case 3). OT efficiency was represented by OT time in five stages (preoperative time, operative time, postoperative time, total OT time, and turnover time). OT time and perioperative outcomes were compared. 102 cases were analysed. On average, Case 1 began at 8:38AM whereas Case 3 ended by 5:54PM. OT efficiency was consistent throughout the day of operation with comparable OT time in all five stages between groups (p > 0.05). The mean turnover time was 15.1 ± 13.5min and themean operative time was 123.0 ± 28.1min. Intraoperative arterial blood gas (ABG) parameters were maintained in an optimal range. Thecomplication rate was 2.0% (N = 2/102). Consistent OT efficiency was demonstrated with a dedicated spine team approach. Despite performing three AIS cases in a consecutive case operation list, patients' safety was not compromised as perioperative outcomes between groups were comparable.

The relation of lactate level and carbon dioxide pressure discrepancies between transcutaneous and arterial measurements.

Partial carbondioxide pressure of the arterial blood (PaCO2) is used to evaluate alveolar ventilation. Transcutaneous carbon dioxide pressure (TcCO2) monitoring has been developed as a non-invasive (NIV) alternative to arterial blood gas analysis (ABG). Studies have shown that decreased tissue perfusion leads to increased carbondioxide (CO2). The use of transcutaneous capnometry may be unreliable in patients with perfusion abnormalities. In this study, we aimed to evaluate the relation between TcCO2-PaCO2 and lactate level which is recognized as a marker of hypoperfusion. In this prospective cohort study in critical care patients with hypercapnic respiratory failure (PaCO2 ≥45 mmHg) who received NIV between April 2019 and January 2020 in the intensive care unit were enrolled in the study. Patients' simultaneously measured TcCO2 and PaCO2 values of hypercapnic patients were recorded. Each paired measurement was categorized into two groups; normal lactate (<2 mmol/L) and increased lactate (≥2 mmol/L). A total of 116 paired TcCO2 and PaCO2 measurements of 29 patients were recorded. Bland-Altman analysis showed the mean bias between the TcCO2 and PaCO2 and 95% limits of agreement (LOA) in all measurements (1.75 mmHg 95% LOA -3.67 to 7.17); in the normal lactate group (0.66 mmHg 95% LOA -1.71 to 3.03); and in the increased lactate group (5.17 mmHg 95% LOA -1.63 to 11.97). The analysis showed a correlation between lactate level and the difference between TcCO2 and PaCO2 (r= 0.79, p< 0.001) and a negative correlation between mean blood pressure and the difference between TcCO2 and PaCO2 (r= -0.54, p= 0.001). Multiple regression analysis results showed that lactate level was independently associated with increased differences between TcCO2 and PaCO2 (Beta= 0.875, p< 0.001). TcCO2 monitoring may not be reliable in patients with increased lactate levels. TcCO2 levels should be checked by ABG analysis in these patients.

The new neural pressure support (NPS) mode and the helmet: did we find the dynamic duo?

BackgroundNoninvasive ventilation (NIV) is commonly used in clinical practice to reduce intubation times and enhance patient comfort. However, patient-ventilator interaction (PVI) during NIV, particularly with helmet interfaces, can be challenging due to factors such as dead space and compliance. Neurally adjusted ventilatory assist (NAVA) has shown promise in improving PVI during helmet NIV, but limitations remain. A new mode, neural pressure support (NPS), aims to address these limitations by providing synchronized and steep pressurization. This study aims to assess whether NPS per se improves PVI during helmet NIV compared to standard pressure support ventilation (PSV).MethodsThe study included adult patients requiring NIV with a helmet. Patients were randomized into two arms: one starting with NPS and the other with PSV; the initial ventilatory parameters were always set as established by the clinician on duty. Physiological parameters and arterial blood gas analysis were collected during ventilation trials. Expert adjustments to initial ventilator settings were recorded to investigate the impact of the expertise of the clinician as confounding variable. Primary aim was the synchrony time (Timesync), i.e., the time during which both the ventilator and the patient (based on the neural signal) are on the inspiratory phase. As secondary aim neural-ventilatory time index (NVTI) was also calculated as Timesync divided to the total neural inspiratory time, i.e., the ratio of the neural inspiratory time occupied by Timesync.ResultsTwenty-four patients were enrolled, with no study interruptions due to safety concerns. NPS demonstrated significantly longer Timesync (0.64 ± 0.03 s vs. 0.37 ± 0.03 s, p < 0.001) and shorter inspiratory delay (0.15 ± 0.01 s vs. 0.35 ± 0.01 s, p < 0.001) compared to PSV. NPS also showed better NVTI (78 ± 2% vs. 45 ± 2%, p < 0.001). Ventilator parameters were not significantly different between NPS and PSV, except for minor adjustments by the expert clinician.ConclusionsNPS improves PVI during helmet NIV, as evidenced by longer Timesync and better coupling compared to PSV. Expert adjustments to ventilator settings had minimal impact on PVI. These findings support the use of NPS in enhancing patient-ventilator synchronization and warrant further investigation into its clinical outcomes and applicability across different patient populations and interfaces.Trial registrationThis study was registered on www.clinicaltrials.gov NCT06004206 Registry URL: https://clinicaltrials.gov/study/NCT06004206 on September 08, 2023.

Delivery Room Lung Ultrasound-Feasibility, Normal Patterns, and Predictive Value for Respiratory Support in Term and Near-Term Neonates: A Monocentric Study.

our study aimed to characterize the lung ultrasound (LUS) patterns noted immediately after delivery in term and near-term neonates, and to investigate whether the LUS scores or patterns observed at that point could anticipate the need for respiratory support in the sample of patients studied. We performed two ultrasound examinations: one in the delivery room and the second at one hour of age. The anterior and lateral regions of both lungs were examined. We assessed the correlation between the LUS scores or patterns and the gestational age, umbilical arterial blood gases, the need for respiratory support (CPAP or mechanical ventilation), the presence of respiratory distress, and the need for the administration of oxygen. LUS scores were significantly higher in the delivery room examination (8.05 ± 1.95) than at 1 h of age (6.4 ± 1.75) (p < 0.001). There were also statistically significant differences between the LUS patterns observed in different lung regions between the delivery room exam and the exam performed at 1 h of age (p values between 0.001 and 0.017). There were also differences noted regarding the LUS patterns between different lung regions at the exam in the delivery room (the right anterior region LUS patterns were significantly worse than the right lateral LUS patterns (p < 0.004), left anterior LUS patterns (p < 0.001), and left lateral LUS patterns (p < 0.001)). A statistically significant correlation was found between LUS scores and the gestational age of the patients (r = 0.568, p < 0.001-delivery room; r = 4.0443, p < 0.001-one hour of age). There were statistically significant associations between LUS scores, patterns at delivery (p < 0.001) and 1 h of age (p < 0.001), and the need for respiratory support (CPAP or mechanical ventilation). LUS in the delivery room offers important information regarding lung fluid elimination and aeration of the lungs, and early LUS features are significantly associated with the risk of respiratory distress and the need for respiratory support.

Comparison of Intercostal and Subxiphoid Left Pleural Drain After Coronary Artery Bypass Grafting (CABG) Surgery: A Systematic Review and Meta-Analysis.

Coronary artery bypass grafting (CABG), a prevalent surgery for coronary artery disease, often involves left internal mammary artery harvesting, necessitating left pleural drain insertion. This can lead to pain, discomfort, and respiratory issues. This analysis compares outcomes between subxiphoid and intercostal left pleural drain insertion. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, this systematic review and meta-analysis involved searches in MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Google Scholar, and Clinical Trial Registry. Studies were selected based on primary outcomes (postoperative ventilator support duration and pain score) and secondary outcomes (percentage predicted vital capacity (VC), forced VC (FVC), and partial pressure of oxygen (PO2) in arterial blood gas (ABG) analysis). Statistical analysis used a random effect model, pooled risk ratio, and I2 heterogeneity. Nine studies (seven randomized and two nonrandomized) with 412 patients met the inclusion criteria. Pooled analysis indicated reduced ventilation time and postoperative pain with the subxiphoid drain compared to the intercostal drain. Spirometry parameters showed improved VC, FVC, and PO2 in ABG analysis. This meta-analysis suggests that subxiphoid pleural drain insertion in CABG patients is associated with shorter ventilation times, lower pain scores, and improved pulmonary function compared to intercostal drain placement.

Silent hypoxemia – A specific sign of COVID-associated pneumonia?

Introduction. Pneumonia is a frequent manifestation of coronavirus infection. COVID-associated pneumonia is a disease characterized by a non-standard course and a number of clinical phenomena that complicate timely diagnosis and treatment.Aim. To investigate the phenomenon of mute hypoxemia in COVID-associated pneumonia.Materials and methods. The study included 214 patients who were divided into 2 groups. The study group included patients with confirmed COVID-associated pneumonia, and the control group included patients with interstitial lung diseases (idiopathic pulmonary fibrosis, nonspecific interstitial pneumonia, hypersensitivity pneumonitis). The subjective condition of the patient, presence of concomitant pathology, high-resolution computed tomography data, arterial blood gas composition, and spirometry data were evaluated.Results. In patients with COVID-associated pneumonia, “silent hypoxemia” was encountered 1.3 times more frequently than in patients with non-COVID-associated pneumonia. When comparing patients with silent hypoxemia and hypoxemia with dyspnea in COVID-associated pneumonia, statistically significantly higher values of PaCO2 and lower values of respiratory rate are observed. Such patterns are not detected in non-COVID-associated pneumonia. In patients with silent hypoxemia in non-COVID-associated pneumonia, the respiratory rate is statistically significantly higher compared to patients with COVID-associated pneumonia. Univariate logistic regression analysis demonstrates that in patients with non-COVID-associated pneumonia, silent hypoxemia is associated with BMI increase (OR = 1.380 (95% CI: 1.058–1.801); p = 0.017).Conclusion. The phenomenon of “silent hypoxemia” may manifest not only in pulmonary impairments resulting from SARS-CoV-2 infection but notably in COVID-associated pneumonia, where the absence of patient-reported dyspnea is substantiated by the lack of tachypnea. Owing to the subtleties of “silent hypoxemia”, clinical presentations may exhibit delays, diverting attention from significant pulmonary compromise, which could subsequently precipitate the failure of compensatory mechanisms.

Differences in Anthropometric, Sleep and Respiratory Characteristics between Hypercapnic and Normocapnic Patients with COPD-OSA Overlap Syndrome.

Overlap syndrome (OS), the coexistence of chronic obstructive pulmonary disease and obstructive sleep apnea, is frequently characterized by the presence of daytime hypercapnia (pCO2 ≥ 45 mmHg). The aim of this study was to investigate potential differences in anthropometric, sleep and respiratory characteristics between hypercapnic and normocapnic patients with OS. Consecutive patients who underwent polysomnography, pulmonary function testing and arterial blood gases and had been diagnosed with OS were enrolled in the study. According to pCO2 levels in wakefulness, the patients were divided into group A, consisting of OS patients without hypercapnia (n = 108) or group B, consisting of OS patients with hypercapnia (n = 55). The majority of included patients in both groups were males (n = 92 in group A vs. n = 50 in group B). Group B had increased BMI (p = 0.001), neck (p = 0.017) and waist circumference (p = 0.013), higher scores in Epworth sleepiness scale (ESS) (p = 0.008), increased sleep efficiency (p = 0.033), oxygen desaturation index (p = 0.004) and time with oxyhemoglobin saturation <90% (p = 0.006) than group A. Also, Group B had decreased average and minimum oxyhemoglobin saturation during sleep (p < 0.001). Hypercapnic patients had lower FEV1% (p = 0.003), FVC% (p = 0.004), pO2 and pCO2 (p < 0.001 for both) values compared with normocapnic patients. In binary regression analysis, which assessed various predictors on the likelihood of having hypercapnia, it was found that BMI (OR: 1.313, 95% CI: 1.048-1.646, p = 0.018) and FVC (OR: 0.913, 95% CI: 0.845-0.986, p = 0.020) were the major determinants of hypercapnia in OS patients. Hypercapnic OS patients were more obese and sleepy and presented worse respiratory function in wakefulness and sleep hypoxia characteristics compared with normocapnic OS patients.

Resting diffusing capacity and severity of radiographic disease predict gas exchange abnormalities with exercise in former US coal miners.

The US Department of Labor (DOL) does not fund diffusing capacity (DLCO) or metabolic measurements from cardiopulmonary exercise testing (CPET) for coal miners' disability evaluations. Although exercise arterial blood gas testing is covered, many miners are unable to perform maximal tests, and sampling at peak exercise can be challenging. We explored the relationship between resting DLCO, radiographic disease severity, and CPET abnormalities in former US coal miners. We analyzed data from miners evaluated between 2005 and 2015. Multivariable linear and logistic regression analyses were used to examine relationships between percent predicted (pp) forced expiratory volume in 1 s (FEV1pp), DLCOpp, VO2maxpp, A-a oxygen gradient (A-a)pp, dead space fraction (Vd/Vt), disabling oxygen tension (PO2), and radiographic findings of pneumoconiosis. Data from 2015 male coal miners was analyzed. Mean tenure was 28 years (SD 8.6). Thirty-twopercent had an abnormal A-a gradient (>150 pp), 20% had elevated Vd/Vt (>0.33), and 34% a VO2max < 60 pp. DLCOpp strongly predicted a disabling PO2, with an odds ratio (OR) of 2.33 [2.09-2.60], compared to 1.18 [1.08-1.29] for FEV1. Each increase in subcategory of small opacity (simple) pneumoconiosis increased the odds of a disabling PO2 by 42% [1.29-1.57], controlling for age, body mass index, pack-years of tobacco smoke exposure, and years of coal mine employment. DLCO is the best resting pulmonary function test predictor of CPET abnormalities. Radiographic severity of pneumoconiosis was also associated with CPET abnormalities. These findings support funding DLCO testing for impairment and suggest the term "small opacity" should replace "simple" pneumoconiosis to reflect significant associations with impairment.

Induced Moderate Hypothermia in Aortic Rupture With Retroperitoneal Bleeding: A Randomized Porcine Study.

Induced hypothermia improves outcome in aortic arch surgery, neonatal neurointensive care, and transplant surgery for example. In contrast, spontaneous hypothermia has been associated with worse outcomes in patients suffering from hemorrhagic shock, mostly explained by its adverse effects on the coagulation system. We investigated if induced hypothermia would impair short-term survival in experimental aortic rupture with retroperitoneal bleeding. Anesthetized pigs were randomized into 2 groups: hypothermia by peritoneal lavage of ice-cold Ringer's acetate and external cooling (n = 10) and normothermia (n = 10). Aortic rupture with retroperitoneal bleeding was induced by endovascular means creating a 6 mm hole in the retroperitoneal portion of abdominal aorta. Survival (primary outcome), hemodynamics, and arterial blood gases including lactate were collected and analyzed up to 180 min after aortic rupture. The body temperature (mean ± standard deviation) in the hypothermic group was 31.5 ± 1.0 °C and 38.7 ± 0.4 °C in the normothermic group at the time for aortic rupture. Survival up to 180 min after the retroperitoneal bleeding was significantly higher in the hypothermic compared with the normothermic group (P = 0.023). Induced hypothermia did not impair survival in this experimental retroperitoneal aortic bleeding model in anesthetized pigs. This finding may indicate a minor role for the coagulation system in this type of bleeding.

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

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. 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. 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 HRand 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. NIPPV was successful in 42 (84%)patients, with improvements in ABG and pH for early recovery and reduced hospital stay.

Prognostic role of unmeasured anions determined by the Stewart approach in septic shock: A prospective cohort study

Background: Unlike standard methods for the analysis of acid-base disturbances, the Stewart approach allows for a precise quantification of unmeasured anions (strong ion gap, SIG). The prognostic value of these unmeasured anions has been reported in various clinical situations in the intensive care unit (ICU), but not specifically in septic shock. The aim of the present study was to assess whether or not the SIG could be a prognostic marker for 28-day mortality in critically ill patients admitted to the ICU for septic shock. Methods: This prospective cohort study was conducted from June 2016 to December 2017 in three ICUs of a French teaching hospital. All patients admitted to the ICU for septic shock and equipped with an arterial blood line were eligible. Oral consent was collected after delivering oral and written information to the patient or his/her family. The SIG was calculated from a complete blood sampling (blood electrolytes and arterial blood gas) collected immediately upon ICU admission. Receiver operating characteristics (ROC) curves were determined to assess the ability of SIG to predict 28-day mortality. Results: A total of 116 patients were analyzed. The 28-day mortality rate was 41.4%. Median (interquartile range [IQR]) SIG at admission was 7.1 (4.6-9.6) mEq/L for the 28-day survivors and 8.0 (6.1-10.3) mEq/L for non-survivors (P = 0.051). The area under ROC of SIG at admission for 28-day mortality prediction was 0.607 (95% confidence interval [CI] 0.504-0.710; P = 0.051). Conclusion: SIG is not a relevant prognostic marker for mortality in septic shock.

Congenital Central Hypoventilation Syndrome: neonatal diagnosis and management

To report a neonatal case successfully treated with non-invasive ventilatory support (NVS), avoiding tracheostomy. Full-term newborn, whose mother uses nocturnal NVS due to CCHS. During the transition period, she presented desaturations associated with hypercapnia and respiratory acidosis, without pulmonary involvement. She developed severe hypoventilation during sleep, with no respiratory effort, peripheral oxygen saturation (SpO2) < 80%, plus respiratory acidosis. While awake, she had good respiratory effort and normal SpO2 without assistance. Noninvasive continuous positive airway pressure and oxygen therapy worsened her condition while sleeping. Complete NVS with nasal interface and bi-level airway positive pressure, inspiratory/expiratory pressure 14-16/4 cm H2O, normalized SpO2 during sleep, and arterial blood gases while awake. Sequencing of the PHOX2B gene confirmed the presence of a heterozygous pathogenic variant with the 20/26 genotype. At 2 months of age, she was discharged maintaining NVS with nasal interface and 0 PEEP, achieving adequate neurodevelopment. We highlight the importance of genetic diagnosis of CCHS in neonates with clinical presentation of early alveolar hypoventilation, especially if there is a family history. We are not aware of other reports of neonatal onset in which NVS prevents IMV, in this potentially lethal pathology.

Exploring the Prevalence of Respiratory Failure in Adults Presenting With Acute Exacerbations of Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) poses a significant global health burden and is a leading cause of morbidity and mortality. Acute exacerbations of COPD often lead to respiratory failure, necessitating a thorough understanding of its prevalence. This study aimed to investigate the prevalence of respiratory failure among adult patients experiencing acute exacerbations of COPD. A descriptive, cross-sectional study was conducted over a span of seven months at the internal medicine department of Hayatabad Medical Complex, Peshawar. A total of 255 adult patients with acute exacerbations of COPD were included, and their demographic data, as well as arterial blood gas (ABG) analysis results, were collected. The prevalence of respiratory failure was defined by specific arterial blood gas criteria. The study revealed a notable prevalence of respiratory failure (41.18%) among COPD patients presenting with acute exacerbations. Factors such as older age and male gender were identified as being associated with a heightened risk of respiratory failure. In conclusion, acute exacerbations of COPD predominantly affect middle-aged males (65.5%), with the 51-60 age group being the most impacted. Respiratory failure was present in over 41% of cases. ABG analysis indicated significant acid-base imbalances, hypoxemia, and hypercapnia, with compensatory chronic respiratory acidosis. These findings highlight the need for targeted interventions to manage and prevent COPD exacerbations, especially in middle-aged men.