Arterial Blood Gas Evaluation Research Articles

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

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. This study aims to assess arterial blood gas evaluation using artificial intelligence algorithms. 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. 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. 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.

Blood gases, acid-base, and metabolic alterations in calves with bronchopneumonia diagnosed via clinical signs and thoracic ultrasonography: A cross-sectional study.

Bronchopneumonia (BP) in calves potentially causes systemic changes. To describe metabolic, arterial blood gas, and acid-base disorders in calves with BP diagnosed by thoracic ultrasound (TUS), Wisconsin score (WISC), and combinations of WISC and TUS. Two hundred thirty-one dairy preweaned dairy calves from 13 dairy farms. Cross-sectional study. Each calf sequentially underwent arterial blood gas evaluation, WISC score, venous sampling, and TUS. Calves were grouped based on a single diagnostic method and combination of WISC and 2 TUS cutoffs (≥1 cm; ≥3 cm) as healthy, upper respiratory tract infection, subclinical BP, and clinical BP. Oxygenation and acid-base variables were unaffected. Glucose concentration in TUS-affected calves was significantly lower (P < .001) than in healthy calves (median ≥TUS1cm = 5.2 mmol/L 25%-75% interquartile range [IQR] 4.5-6.1, <TUS1cm = 5.9 mmol/L IQR 5.5-6.6; ≥TUS3cm = 5.1 mmol/L IQR 4.4-6.2, <TUS3cm = 5.8 mmol/L IQR 5.3-6.4). Paraoxonase-1 was significantly lower (P < .001) in TUS-affected calves (≥TUS1cm = 64.1 U/mL IQR 40.8-78, <TUS1cm = 77.3 U/mL IQR 61.9-96.5; ≥TUS3cm = 59.2 U/mL IQR 37.7-72.4, <TUS3cm = 72.9 U/mL IQR 53.4-95.5). None of the variables highlighted clear distinctions in WISC-detected clinical and subclinical BP calves based on the combination of WISC and TUS. Clinical signs indicate minor systemic disorders compared to TUS. The abnormalities detected by ultrasonographic examination were moderate and did not deviate from normal reference ranges.

Evaluation of Malignant Hyperthermia Features in Patients with Pathogenic or Likely Pathogenic RYR1 Variants Disclosed through a Population Genomic Screening Program.

Malignant hyperthermia (MH) susceptibility is a heritable musculoskeletal disorder that can present as a potentially fatal hypermetabolic response to triggering anesthesia agents. Genomic screening for variants in MH-associated genes RYR1 and CACNA1S provides an opportunity to prevent morbidity and mortality. There are limited outcomes data from disclosing variants in RYR1, the most common MH susceptibility gene, in unselected populations. The authors sought to identify the rate of MH features or fulminant episodes after triggering agent exposure in an unselected population undergoing genomic screening including actionable RYR1 variants. The MyCode Community Health Initiative by Geisinger (USA) is an electronic health record-linked biobank that discloses pathogenic and likely pathogenic variants in clinically actionable genes to patient-participants. Available electronic anesthesia and ambulatory records for participants with actionable RYR1 results returned through December 2020 were evaluated for pertinent findings via double-coded chart reviews and reconciliation. Descriptive statistics for observed phenotypes were calculated. One hundred fifty-two participants had an actionable RYR1 variant disclosed during the study period. None had previous documented genetic testing for MH susceptibility; one had previous contracture testing diagnosing MH susceptibility. Sixty-eight participants (44.7%) had anesthesia records documenting triggering agent exposure during at least one procedure. None received dantrolene treatment or had documented muscle rigidity, myoglobinuria, hyperkalemia, elevated creatine kinase, severe myalgia, or tea-colored urine. Of 120 possibly MH-related findings (postoperative intensive care unit admissions, hyperthermia, arterial blood gas evaluation, hypercapnia, or tachycardia), 112 (93.3%) were deemed unlikely to be MH events; 8 (6.7%) had insufficient records to determine etiology. Results demonstrate a low frequency of classic intraanesthetic hypermetabolic phenotypes in an unselected population with actionable RYR1 variants. Further research on the actionability of screening for MH susceptibility in unselected populations, including economic impact, predictors of MH episodes, and expanded clinical phenotypes, is necessary.

HAEMATOLOGICAL ALTERATIONS IN CALVES WITH ACUTE RESPIRATORY DISTRESS SYNDROME DUE TO ASPIRATION PNEUMONIA: A PROSPECTIVE STUDY

The aim of this prospective study was to investigate the arterial blood gas (ABG) analysis, which is considered the gold standard, and complete blood count (CBC) as a complementary test in neonatal calves with acute respiratory distress syndrome (ARDS) due to aspiration pneumonia. Ten healthy and 20 calves with ARDS due to aspiration of milk/colostrum were enrolled in the study. Clinical examinations were performed at admission. ABG analyses were performed to determine the presence of ARDS and investigate the extent of lung ventilation/damage. CBC analysis was performed from venous blood samples. Heart and respiratory rates and body temperature values were higher in diseased calves than healthy ones (p &lt; 0.000). Arterial pH, partial pressure of oxygen in arterial blood (PaO2) and saturation of oxygen in arterial blood (SaO2) were lower (p &lt; 0.001) in the diseased calves, while partial pressure of carbon dioxide in arterial blood (PaCO2) and lactate levels were higher (p &lt; 0.000) than those in healthy ones. Also, leukocyte (WBC), lymphocyte, monocyte, granulocyte, mean corpuscular volume (MCV), and mean corpuscular haemoglobin (MCH) levels were higher in the diseased calves than the healthy calves (p &lt; 0.032). As a result of the correlation analysis, the only correlation was determined to be between PaO2 and WBC, which was moderately negative. As a result, it was observed that leukocytosis developing in respiratory diseases that cause severe inflammatory processes such as aspiration pneumonia was negatively correlated with PaO2 and could potentially exacerbate hypoxia, and ABG evaluation with CBC could provide useful clinical data in calves with ARDS due to aspiration pneumonia.

Reliability of smartphone measurements of peripheral oxygen saturation and heart rate in hypotensive patients measurement of vital signs with smartphones

ObjectiveWith the increasing use of wearable technologies (smartphones and smartwatches), it has become possible to measure vital signs outside healthcare institutions without the need for an additional medical device. With the advancement in technologies, the accuracy of vital signs measured by smartphones and smartwatches has also increased. In this study, the accuracy of smart devices in the measurement of heart rate and saturation, which are two vital signs that are difficult to detect in conditions such as hypotension were investigated. Materials and methodsThe study was prospectively conducted in a tertiary healthcare center. In hypotensive patients who presented to the emergency department (ED) and required an arterial blood gas evaluation, oxygen saturation and heart rate values measured by a smartphone, those measured with a vital signs monitor (VSM) at the time of admission to the ED and oxygen saturation values measured by a blood gas analyzer (BGA) were compared. ResultsA total of 200 patients, 117 women and 83 men, were included in the study. It was determined that the correlation coefficients of the heart rate values measured by the vital signs monitor and smartphone were in a high statistical agreement. When the saturation values measured by the vital signs monitor, smartphone, and blood gas analyzer were compared, it was found that the intra-class correlation coefficients of the saturation values measured by the smartphone with reference to the blood gas analyzer and vital signs monitor were 0.957 and 0.949, respectively, indicating an excellent agreement. ConclusionSmartphones have as high efficiency as reference devices in measuring heart rate and saturation in hypotensive patients. In this way, hypotensive patients who need medical help can also have the opportunity to measure their vital parameters with their smartphones, without the need for any other medical device, before applying to the hospital or emergency health system. This may contribute to the improvement of the quality of life of the patients and the early and accurate information of the health care providers about the patient's health parameters.

Pulmonary complications in dogs with acute presentation of pancreatitis

BackgroundIn humans, respiratory complications in patients with acute pancreatitis (AP) are a common life-threatening comorbidity. Since possible lung impairment has not been individually evaluated in canine AP, the aims of the present study were to: (1) describe the prevalence, types and severity of pulmonary complications in dogs with acute presentation of AP, and (2) evaluate their association with mortality. AP diagnosis was based on compatible clinical and laboratory parameters, abnormal canine pancreatic-lipase test, and positive abdominal ultrasound within 48 h from admission. The canine acute pancreatitis severity score (CAPS) was calculated for each dog at admission. Arterial blood gas analysis and thoracic radiography were performed at admission. Thoracic radiography was classified on the basis of pulmonary pattern (normal, interstitial or alveolar) and a modified lung injury score (mLIS) was applied to the ventrodorsal projections for each dog. VetALI/VetARDS were diagnosed using current veterinary consensus. Dogs were divided into non-survivors or survivors (hospital discharge). Clinical, radiological and blood gas parameters collected at presentation were compared between survivors and non-survivors and associated with mortality.ResultsThis prospective cohort study included twenty-six client-owned dogs with AP. Twelve out of twenty-six dogs (46%) died or were euthanized. At admission, thirteen dogs showed respiratory distress at physical examination, which was associated with death (P < 0.001). Radiographic abnormalities were found in twenty-one dogs: alveolar (n = 11) and interstitial pattern (n = 10). Radiographic alterations and mLIS score were both associated with death (P = 0.02 and P = 0.0023). The results of the arterial blood-gas evaluation showed that non-survivors had lower PaCO2 and HCO3− levels, and higher A-a gradient than survivors (P = 0.0014, P = 0.019 and P = 0.004, respectively). Specifically, three dogs had aspiration pneumonia, and VetALI was diagnosed in nine dogs (34.6%), and no dogs met the criteria for VetARDS. The presence of VetALI was associated with mortality (P < 0.001).ConclusionsAs with humans, possible lung impairments, such as VetALI, should be investigated in dogs with acute presentation of pancreatitis.

Iatrogenic tracheal rent in a Clydesdale colt

A one-month-old Clydesdale colt presented for bilateral scrotal hernia and a patent urachus. Manual reduction of the hernia followed by castration and primary closure of the superficial inguinal rings bilaterally...

Evaluation of Emergency Medicine Residents’ Level of Knowledge of Arterial Blood Gases

Objective: Our purpose in this study was to determine the accuracy and reliability of interpretation of basic arterial blood gas (ABG) values and ABG values related to metabolic and respiratory disease by emergency medicine residents (EMRs). We also aimed to determine their deficiencies and create a basis for training during patient care. Material and Methods: This study was carried out through a survey taken by EMRs in training/research and university hospitals located in Ankara. The levels of knowledge of EMRs on ABG evaluation were compared based on the institution, duration of residency, and training. A 14-question test about ABG knowledge was also applied to residents. Results: The study was conducted with 25 EMRs in university hospitals (UH) and 88 EMRs in training/research hospitals (TRH); a total of 113 residents participated to the survey. There was no statistical significant difference between training/research and university hospitals according to the number of correct answers given. Year of residency did not affect the number of correct answers; however, residents who had training on ABG analysis in the residency period had more correct answers. Also, in a small study group (n=17), a significant improvement of the number of correct answers was observed with a short institutional course. Conclusion: According to the results, ABG evaluation improves with personal training in the residency period independently of residency years. Based on this result, training should be given in and out of institutions, and EMRs should be encouraged to personally study ABG evaluation. (JAEM 2014; 13: 100-3)

Recumbent deoxygenation in mild/moderate liver cirrhosis: the “Clinodeoxia”. The ortho-clino paradigm

While the effects of postural change on arterial oxygenation have been well documented in normal subjects, and attributed to the relationship of closing volume (CV) to the tidal volume, in liver cirrhosis such postural changes have been evaluated mainly in a rare, peculiar clinical end-stage condition which is characterized by increased dyspnea shifting from supine to upright position ("platypnea"). The latter is associated with worsening of PaO2 ("orthodeoxia"). We evaluated the effects of postural changes on arterial oxygenation in patients affected by mild/moderate liver cirrhosis. We performed pulmonary function tests and arterial blood gas evaluation in sitting and supine positions in 22 patients with mild/moderate liver cirrhosis, biopsy-proved, and 22 matched non-smokers control subjects. Recumbency elicited a decrease of PaO2 (Δ(sup-sit)PaO2) in 19 out of 22 controls and in all but one cirrhotics. The magnitude of this postural change was significantly (p=0.04) greater in cirrhotics (9.6±5.3%) compared to controls (6.7±3.7%). In the subset of cirrhotics younger than 60yrs and with PaO2 greater than 80mmHg in sitting position, the Δ(sup-sit)PaO2 in recumbency further increased to 12±5.8%, significantly (p=0.014) greater than in same subgroup of controls (7.1±3.8%). In mild/moderate liver cirrhosis the postural variations in PaO2 follow the normal trends, but are of greater magnitude probably as a consequence of hypoventilated units of lung for postural and disease-linked tidal airway closure, resulting in more pronounced recumbent hypoxemia ("clinodeoxia").

Circulating endothelin-1 concentrations in patients with chronic hypoxia.

To evaluate the behavior of plasma endothelin-1 in patients with chronic hypoxia. Fifteen male patients (mean age 52.1 +/- 3.1 years) with mild chronic obstructive pulmonary disease (COPD) were studied. Twelve healthy men (mean age 48.3 +/- 5.4 years) served as controls. Both patients and controls underwent standard pulmonary function tests, echocardiographic evaluation, and arterial blood gas evaluation. Blood samples for endothelin-1 assay were taken from a previously incannulated antecubital vein after 60 minutes of rest in the supine position. Endothelin-1 was measured by radioimmunoassay after extraction from plasma. Patients with chronic hypoxia had lower PaO2 values (66.1 +/- 6.2 mmHg) than controls (83.8 +/- 2.7 mmHg) but PaCO2 values were similar (38.1 +/- 2.5 v 36.7 +/- 3.1 mmHg, respectively). Arterial pulmonary pressure, therefore, was higher in patients (18.1 +/- 3.7 mmHg) than in controls (10.4 +/- 2.7 mmHg) as were circulating endothelin-1 concentrations (1.22 +/- 0.36 v 0.57 +/- 0.1 pg/ml). Furthermore, plasma endothelin-1 concentrations were negatively correlated with PaO2 and directly correlated with pulmonary pressure levels. No significant correlations were found in controls. These results show a clear relation between chronic hypoxia and circulating endothelin-1 concentrations. Therefore, chronic hypoxia may be regarded as an important stimulus for endothelin-1 release and as one of the main contributors to increased vasoconstriction in the vascular pulmonary bed which often accompanies lung disease.

Utility of routine admission serum chemistry panels in adult trauma patients.

To determine the frequency of abnormal serum chemistries and whether they provide clinically useful information regarding trauma patients. To identify clinical criteria associated with critical serum chemistry values (CSCVs). The records of all trauma patients admitted to one urban, Level I Trauma Center were retrospectively reviewed for the period (July 1-December 31, 1989). All trauma patients who had had serum chemistry determinations at hospital admission and at least once more prior to discharge were studied. The CSCVs were determined by a panel of experts prior to record review. Serum chemistry values, patient demographics, mechanisms of injury, and outcomes were statistically analyzed. Most (814/913; 89%) trauma patients had abnormal serum chemistry values. However, only 54/913 (6%) had CSCVs and only six of these CSCVs had prompted a change in resuscitation or treatment (therapeutic K+ infusions). Age > 50 years, a history of hypertension therapy, and a Glasgow Coma Scale score < or = 10 were associated with CSCVs; and CSCVs were correlated with increased mortality and critical care unit admission. Routine-admission serum chemistry values, while frequently abnormal for major trauma patients, generally do not provide clinically useful information in the resuscitation and treatment of trauma patients. Hypoglycemia and metabolic acidosis were more rapidly determined using bedside glucose determination and arterial blood gas evaluation. The routine-admission serum chemistry panel described in the study lacked utility for most trauma patients. Selective chemistry panel ordering should be used at the time of hospital admission for major trauma patients.

Occult Mucous Airway Obstruction in Diabetic Ketoacidosis

Four patients with diabetes mellitus and no underlying clinical pulmonary disease were found to have extensive unilateral mucous occlusion of a major central bronchus. None of the patients had significant auscultatory findings suggestive of pulmonary secretions, and chest roentgenographic films were normal. Arterial blood gas evaluation failed to reveal the usual hypocapnia during ketoacidosis, thus prompting bronchoscopic examination or deep airway suctioning. These interventions disclosed and resolved the mucous obstruction of the compromised bronchus. Antibiotic therapy, based upon bronchial secretion Gram stain and culture, was successfully instituted in all patients. Lethargy and autonomic neuropathy are proposed as contributing factors responsible for occult mucous plugging in diabetic patients in ketoacidosis. The absence of hypocapnia in this setting may be the only clue to silent mucous plugging of airways.