Changes In Blood Gases Research Articles

Clinical, Hematological, Blood Gasometric and Electrolytic Changes in Dogs Receiving Whole Blood Transfusions

Background: Blood transfusion is a tool capable of saving lives. Patients undergoing blood transfusion usually present several alterations in the acid-base and electrolyte balance, aggravating the condition of critically ill patients. Some studies have demonstrated haematological alterations in certain species that received whole blood transfusions, however, few studies have evaluated acid base and electrolyte changes in dogs undergoing whole blood haemotherapy. The aim of this study was to analyze clinical, hematological, blood gas and electrolyte changes in anemic dogs after whole blood transfusion.Materials, Methods & Results:Twenty nine dogs transfused due to anemia were enrolled in the study. Donors blood was collected in a transfusion bag containing citrate phosphate adenine dextrose and stored up to 24 h. Blood collections and evaluations were made before and 24 h after the transfusion. Data distribution normality was tested by the Shapiro Wilk Test. The means of the variables were compared by paired t-test. It was observed an increase in diastolic blood pressure and a reduction in heart rate (P < 0.05). There was a not significant increase in systolic blood pressure, temperature, and a reduction in respiratory rate per minute. Erythrocyte, haemoglobin and haematocrit averages were significantly increased after blood transfusion (P < 0.05). It was observed a reduction in the mean values of pH (P < 0.05), potassium (P > 0.05) and ionized calcium (P > 0.05) and an increase in the mean partial pressure of carbon dioxide (pCO2) (P < 0.001), bicarbonate (P > 0.05) and sodium (P < 0.05). The probable cause of anemia was monocytic ehrlichiosis (14/29), visceral leishmaniasis (1/29), babesiosis (1/29), co-infection of Ehrlichia canis and Leishmaniainfantum (2/19), co-infection of E. canis and Babesia vogeli (1/19). It was not possible to determine the etiology of the anemia in ten dogs. Discussion:Heart rate significantly reduced after transfusion, probably because of the increase in hematocrit, hemoglobin and erythrocyte values. It may be justified by the displacement of extravascular fluid to the intravascular space. Mean values of systolic blood pressure were slightly elevated before transfusion and remained elevated afterwards, while diastolic and mean arterial pressure increased significantly after transfusion. These changes may be due to the morbid condition and may be influenced by many other factors. Haematocrit, haemoglobin and erythrocyte values increased significantly after transfusion, according to what was observed in other studies. The significant reduction in pH and increase in pCO2 reflects the compensatory mechanism for metabolic acidosis to increase ventilation, leading to pCO2 reduction and changes in pH. The reduction in pH due to the contact of the collected blood with conservative solutions is one of the main changes thar occurs during blood storage. It was described significantly lower pH in dogs’ whole blood samples stored for more than 24h in vacutainer plastic containing CPDA-1. We may assume there was no intense pH reduction in the present study because the bags were stored for up to 24 h. Although not statistically significant, the increase of pO2 mean reflects the improvement of tissue oxygen perfusion. It was observed a significant increase in sodium ions. The mean sodium ionconcentration before transfusion was very close to the maximum reference value. Hyperkalaemia was not observed, nor was there significant reduction of potassium ions after transfusion. Several studies report hyperkalaemia and transfusion-associated cardiac arrests in humans, associated with infusion of large volumes of blood. Whole blood transfusion increased erythrogram values and did not negatively affect the electrolyte or acid-base status, representing a safe and useful tool in the intensive care of small animals.

Invasive Assessment of Hemodynamic, Metabolic and Ionic Consequences During Blood Flow Restriction Training.

Purpose: Medically recommended training often faces the dilemma that necessary mechanical intensities for muscle adaptations exceed patients' physical capacity. In this regard, blood flow restriction (BFR) training is becoming increasingly popular because it enables gains in muscle mass and strength despite using low-mechanical loads combined with external venous occlusion. Since the underlying mechanisms are still unknown, we applied invasive measurements during exercise with and without BFR to promote physiological understanding and safety of this popular training technique.Methods: In a randomized cross-over design, ten healthy men (28.1 ± 6.5 years) underwent two trials of unilateral biceps curls either with (BFR) and without BFR (CON). For analysis of changes in intravascular pressures, blood gases, oximetry and electrolytes, an arterial and a venous catheter were placed at the exercising arm before exercise. Arterial and venous blood gases and intravascular pressures were analyzed before, during and 5 min after exercise.Results: Intravascular pressures in the arterial and venous system were more increased during exercise with BFR compared to CON (p < 0.001). Furthermore, arterial and venous blood gas analyses revealed a BFR-induced metabolic acidosis (p < 0.05) with increased lactate production (p < 0.05) and associated elevations in [K+], [Ca2+] and [Na+] (p < 0.001).Conclusion: The present study describes for the first time the local physiological changes during BFR training. While BFR causes greater hypertension in the arterial and venous system of the exercising extremity, observed electrolyte shifts corroborate a local metabolic acidosis with concurrent rises in [K+] and [Na+]. Although BFR could be a promising new training concept for medical application, its execution is associated with comprehensive physiological challenges.

Face Masks and the Cardiorespiratory Response to Physical Activity in Health and Disease.

To minimize transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the novel coronavirus responsible for coronavirus disease (COVID-19), the U.S. Centers for Disease Control and Prevention and the World Health Organization recommend wearing face masks in public. Some have expressed concern that these may affect the cardiopulmonary system by increasing the work of breathing, altering pulmonary gas exchange and increasing dyspnea, especially during physical activity. These concerns have been derived largely from studies evaluating devices intentionally designed to severely affect respiratory mechanics and gas exchange. We review the literature on the effects of various face masks and respirators on the respiratory system during physical activity using data from several models: cloth face coverings and surgical masks, N95 respirators, industrial respirators, and applied highly resistive or high–dead space respiratory loads. Overall, the available data suggest that although dyspnea may be increased and alter perceived effort with activity, the effects on work of breathing, blood gases, and other physiological parameters imposed by face masks during physical activity are small, often too small to be detected, even during very heavy exercise. There is no current evidence to support sex-based or age-based differences in the physiological responses to exercise while wearing a face mask. Although the available data suggest that negative effects of using cloth or surgical face masks during physical activity in healthy individuals are negligible and unlikely to impact exercise tolerance significantly, for some individuals with severe cardiopulmonary disease, any added resistance and/or minor changes in blood gases may evoke considerably more dyspnea and, thus, affect exercise capacity.

Hypercapnia and hyperlactatemia were positively associated with higher-grade arrhythmias during peak exercise in horses during poor performance evaluation on a high-speed treadmill

Cardiac arrhythmias are common in horses during exercise, especially immediately post-exercise. The objectives of this study were to: (1) describe the frequency and type of cardiac arrhythmias detected in horses during incremental high-speed treadmill exercise testing (ITET); (2) determine if arterial blood gas (ABG) changes at peak and immediately post-exercise were associated with arrhythmias; and (3) determine whether upper or lower airway disease was associated with exercising cardiac arrhythmias. Horses (n = 368) presenting for an ITET underwent resting and exercising upper airway endoscopy, resting, exercising and post-exercise electrocardiography, resting and post-exercise echocardiography and exercising ABG. Arrhythmias were graded by the most severe arrhythmia present. Grade 1 arrhythmias were defined as one or two atrial (APCs) or ventricular premature complexes (VPCs), or one APC and one VPC, detected in 6.9% at peak and 16% at 0-2 min post exercise.. Grade 2 arrhythmias were >2 APCs or VPCs, or both, detected in 5.8% at peak and 16.6% at 0-2 min post exercise. Grade 3 included complex arrhythmias (couplets, triplets, R on T, multiform complexes or paroxysmal atrial or ventricular tachycardia), detected in 4.4% at peak and 7.3% at 0-2 min post exercise.Both partial pressure of arterial CO2 (PaCO2; P = 0.008) and lactate (P = 0.031) were significantly associated with arrhythmias occurring at peak exercise, but not immediately post-exercise. As PaCO2 and lactate increased, arrhythmia severity increased. Blood pH was significantly associated with grades 2 and 3 arrhythmias at 0–2 min post ITET (OR = 0.0002; P < 0.001). There was no significant association between grades 2 and 3 cardiac arrhythmias, inflammatory airway disease (IAD), or exercise-induced pulmonary hemorrhage (EIPH). When adjusted for lactate concentration (P = 0.06), higher PaCO2 concentrations in horses with and without exercising upper respiratory tract (URT) obstruction were associated with higher likelihood of grades 2 and 3 arrhythmias (P < 0.01). This study demonstrated that at peak exercise, with severe hypercapnia and hyperlactatemia, there was increased risk for grades 2 or 3 cardiac arrhythmias and, as the PaCO2 and lactate values increased further, the severity of those arrhythmias increased.

Development in PaCO2 over 12 months in patients with COPD with persistent hypercapnic respiratory failure treated with high-flow nasal cannula—post-hoc analysis from a randomised controlled trial

IntroductionPersistent hypercapnic failure in chronic obstructive pulmonary disease (COPD) is associated with poor prognosis. Long-term home non-invasive ventilation is recommended for patients with PaCO2 >7.0 kPa. Domiciliary high-flow nasal cannula...

Impact of rapid versus gradual changes in arterial partial pressure of carbon dioxide on blood flow and myocardial oxygenation in an experimental anaesthetized model

Introduction Hyper- and hypocapnia have known vaso-modulatory effects in the coronary circulation. Oxygenation-sensitive cardiovascular magnetic resonance (OS-CMR) detects changes in tissue oxygenation and can provide a comprehensive assessment of the impact of systemic blood gas changes on the myocardium. The purpose of this study was to compare the physiological responses to rapid blood gas changes induced by hyperventilation followed by apnea in comparison to steady-state levels of hypocapnia and hypercapnia in an experimental animal model. Methods Eighteen anaesthetized female swine were used in this study. A blood flow probe was attached to the left descending coronary artery (LAD) after a left-sided thoracotomy. In ten animals a hemodynamically significant LAD stenosis was induced, while eight animals served as controls. In a 3 Tesla MRI, paCO2 was modulated from a pre-set baseline (paO2=100mmHg/paCO2=40mmHg) to 30mmHg and subsequently 50mmHg by minor changes in ventilation rate. Rapid changes in paCO2 were achieved by 60s of hyperventilating (30/min) from baseline followed by an apnea of up to 90 seconds. OS-CMR images, coronary blood flow (CBF) of the LAD and arterial blood gases were recorded at each state. Results Targeting stable hypocapnia of 30mmHg from baseline did not alter CBF or myocardial oxygenation. Subsequent stable hypercapnia (paCO2=50mmHg) increased CBF significantly in control (5±5%, p=0.007) and stenosed (4±6%, p=0.036) animals, and myocardial oxygenation rose in both post-stenotic territories (4.2±6.2%, p=0.036) and in control subjects (6.2±6.2%, p=0.011). Rapid hyperventilation induced a similar degree of hypocapnia (control: paCO2=25±7mmHg, stenosed: 27±3mmHg) and showed a significant decrease of CBF by -34±23% (p=0.012) in healthy animals, and a significant decrease of -10±6% (p=0.010) in stenosed animals. This had no effect on tissue oxygenation. Apnea resulted in a similar paCO2 (control: paCO2=52±9mmHg, stenosed: 47±7mmHg) compared to steady-state blood gas levels, which increased CBF significantly in controls 346±327% (p=0.008) and stenosed 82±110 (p=0.039) animals markedly. By the end of apnea, a rise in tissue oxygenation of 2.9±2.2% was observed in controls (p=0.008), -2.7±5.1 (0.125) was observed in the stenosed group (Figure). Significant difference in myocardial oxygenation responses observed between control and stenosed subject was exclusively observed with apnea (p=0.011). Discussion Rapid hyperventilation followed by apnea results in more pronounced changes in myocardial blood flow than similar steady state deflections in paCO2. Only apnea after hyperventilation induced deoxygenation in the stenotic myocardium, which is in agreement with the concept of hypercapnia induced intercoronary steal, while steady state deviation did not compromise myocardial oxygenation. Similar breathing maneuvers may be seen in the induction phase of anaesthesia, which could potentially be a harbinger of perioperative ischemic myocardial events.

Epidemiological and Clinical Features of Patients Suffering from Severe Pneumonia Caused by RSV in the Respiratory Center of the Viet Nam National Children's Hospital

Background/Purpose: Pneumonia is a common respiratory and life-threatening disease in pediatrics. Virus is an important cause of pneumonia in children, of which Respiratory syncytial virus (RSV) is the most common cause. The aim of this research is to access the clinical, epidemiological features and risk factors of patients suffering from RSV severe pneumonia.&#x0D; Methods: We studied 250 patients suffering from severe pneumonia caused by RSV from June 2019 to December 2019 in the Respiratory Center of the Vietnam National Children’s Hospital.&#x0D; Results: In Respiratory Center of our hospital, 3472 hospitalizations caused by pneumonia occurred in the last 6 months in 2019; 7.2% of these caused by RSV severe pneumonia. Pneumonia caused by RSV occurred most in male (66,7%), the rate of male/female = 2/1. The mean age was 4,94 ± 6,04 months. The prevalence of RSV in age groups is, respectively, as follows: less than 3 months (21,3%), from 3 months to 6 months (23,4%), from 6 months to 12 months (27%), from 12 months to 24 months (19%), over 2 years (9,3%). The most common symptoms which were accounted for over 80% were rhinorrhea, cough, wheeze, tachypnea and chest recession. The rate of admission increased sharply in December with 25.1% of cases. All hospitalized patients had respiratory distress symptoms with the frequent changes in blood gas, accounting for 59.2% of hypercapnia. The mean of hospitalization was 6,2 ± 7,4 days.&#x0D; Conclusion: the rate of RSV infection increased in the last 6 months in 2019. Most of patients who less than 1 year of age were admitted to hospital because of severe clinical symptoms and respiratory distress. Risk factors were related to the severity of RSV severe pneumonia were: premature, mal-nutrition, bronchopulmonary dysplasia.

Comparison of the Clinical Outcomes Between Nebulized and Systemic Corticosteroids in the Treatment of Acute Exacerbation of COPD in China (CONTAIN Study): A Post Hoc Analysis.

Background and ObjectiveAlthough corticosteroids have been widely used in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD), few studies have evaluated the effectiveness of nebulized corticosteroids (NCS), systemic corticosteroids (SCS), and NCS plus SCS in the management of AECOPD in China. This study aimed to evaluate the effectiveness of NCS, SCS, and NCS plus SCS in Chinese patients with AECOPD.Patients and MethodsThis was a real-world study of AECOPD patients at 43 sites from January to September 2014. During hospitalization, patients treated with nebulized budesonide (NCS group, n=1091), SCS (SCS group, n=709), or both (NCS+SCS group, n=1846) were included. Propensity score matching (PSM) and subgroup analyses were performed. The primary outcomes were the length of hospital stay, mortality, and change in arterial blood gases from baseline.ResultsMultivariable analysis showed that the three treatments at the same severity of AECOPD were not significantly different regarding intubation rates, rates of pneumonia improvement at discharge, rates of new-onset pneumonia in hospital, and mortality. Following PSM, NCS+SCS was associated with greater length of hospital stay than both NCS and SCS (in patients without respiratory failure [RF, P<0.001] and with type I RF [P=0.022]), and more hospitalization costs than the other two treatments (in patients without RF [P<0.001]).ConclusionNCS is effective for patients with AECOPD, which may be an alternative treatment option. Further clinical trials are urgently needed to better understand the efficacy of NCS, SCS, and NCS+SCS in AECOPD management in China.

CARDIAC chronotropic effects of sleep-disordered breathing in patients with heart failure.

It is still not known whether the oscillation in heart rate (HR) induced by sleep-disordered breathing (SDB) in patients with heart failure entails significant chronotropic effects. We hypothesised that since cyclical changes in ventilation and arterial blood gases during SDB affect HR through multiple and complexly interacting mechanisms characterised by large inter-subject variability, chronotropic effects may change from patient to patient. A total of 42 patients with moderate-to-severe chronic heart failure with systolic dysfunction underwent an in-hospital sleep study. Chronotropic effects of SDB were quantified by comparing the distribution of instantaneous HR during SDB with that during periods without SDB (noSDB) within the same night in each patient. Based on distribution changes from noSDB to SDB, 12, nine, 11, and 10 patients showed a significant tachycardic, bradycardic, tachycardic and bradycardic, and neither significant tachycardic nor significant bradycardic effect, respectively. Tachycardic and bradycardic effects were primarily due to an increase in the rate rather than in the magnitude of cyclical HR elevations and reductions, and were more prevalent and severe in patients with dominant obstructive and central events, respectively. The apnea-hypopnea index did not differ between groups. Conversely, the time spent with an oxygen saturation of <90% was greater in the tachycardic and tachycardic-bradycardic groups compared to the bradycardic group. These findings indicate that HR distribution changes induced by SDB can vary from patient to patient revealing four distinct and well-characterised chronotropic effects. These effects are related to the degree of hypoxic burden brought about by SDB and are affected by the type of sleep apnea (central/obstructive).

Sympathetic activation: a potential link between comorbidities and COVID-19.

In coronavirus disease 2019 (COVID‐19), higher morbidity and mortality are associated with age, male gender, and comorbidities, such as chronic lung diseases, cardiovascular pathologies, hypertension, kidney diseases, diabetes mellitus, and obesity. All of the above conditions are characterized by increased sympathetic discharge, which may exert significant detrimental effects on COVID‐19 patients, through actions on the lungs, heart, blood vessels, kidneys, metabolism, and/or immune system. Furthermore, COVID‐19 may also increase sympathetic discharge, through changes in blood gases (chronic intermittent hypoxia, hyperpnea), angiotensin‐converting enzyme (ACE)1/ACE2 imbalance, immune/inflammatory factors, or emotional distress. Nevertheless, the potential role of the sympathetic nervous system has not yet been considered in the pathophysiology of COVID‐19. In our opinion, sympathetic overactivation could represent a so‐far undervalued mechanism for a vicious circle between COVID‐19 and comorbidities.

Investigation of Arterial Blood Gas in Radial Artery in Patients with Observative Sleep Apnea Syndrome

Objective: Apnea developing during sleep prevents gas exchange in the body for 10 seconds or more. As a result, there is a significant decrease in partial oxygen pressure (PaO2) and a significant increase in partial carbon dioxide pressure (PaCO2). Patients with Obstructive Sleep Apnea Syndrome (OSAS) have systemic hypertension, heart failure, arrhythmia, chronicle artery disease, cerebrovascular diseases, and sudden death. The aim of this study is to determine the undiagnosed OSAS by looking at arterial blood gas changes in the radial artery.Materials and Methods: In this study, the patients were divided into two groups according to the severity of OSAS (the first group consisted of 13 patients, Apnea-Hypopnea Index 5 Ap15 and the second group consisted of 11 patients, Apnea-Hypopnea Index 16 and above). Blood samples were taken from radial arteries of patients in two groups. Arterial blood gases between groups; PaO2, PaCO2, arterial oxygen saturation (SaO2), hydrogen ion concentration (pH) values and accompanying diseases were examined.Results: There was no significant difference between the arterial blood gases values of patients in two groups. This suggests that arterial blood gas values in the blood taken from the radial artery alone cannot diagnose or fail to diagnose OSAS. However, patients in the two groups; 88% chronic obstructive pulmonary disease (COPD) was found as the concomitant disease. This suggests us thinking that the abnormal blood gas values (PaO2 level below normal limits and PaCO2 level above normal limits) is associated with COPD which accompanies the disease with OSAS.Discussion: Identification and treatment of OSAS prevent the development of complications associated with OSAS and may provide treatment for OSAS. Undiagnosed OSAS may be considered in the presence of abnormalities in the examination of arterial blood gas in the radial artery in patients presenting with OSAS findings (such as snoring, witnessed apnea, daytime sleepiness etc.) and accompanying COPD.This paper is just a sample template for the prospective authors of IISTE Over the decades, the concepts of holons and holonic systems have been adopted in many research fields, but they are scarcely attempted on labour planning. A literature gap exists, thus motivating the author to come up with a holonic model that uses exponential smoothing to forecast some quantitative variables in labour-intensive production. These varying parameters include the machine utilisation that reflects the demand and the worker absenteeism and turnover that constitute the disturbance. Collective equations are formulated to periodically compute the number of workers required. For model validation purpose, twenty-four-month data analysis is conducted on a mock-up basis. Keywords: OSAS; Polysomnography; PaO2; PaCO2; SaO2 DOI: 10.7176/JHMN/74-05 Publication date: May 31 st 2020

Seizures in patients with respiratory disease - a retrospective single center study.

Seizures are a neurological condition commonly experienced during the follow-up period after systemic or metabolic disorders. The aim of the present study was to determine the etiological factors of seizures in patients at a tertiary care chest clinic. We reviewed all neurology consultations that were requested due to seizures in inpatient clinics in a tertiary care hospital specializing in respiratory disorders between January 2011 and January 2018 were retrospectively reviewed. The present study included 705 of 2793 (25.2%) patients who requested consultations for seizures during the study period. The mean age of the sample was 64.05±17.19 years. Of the 705 patients, 307 (43.5%) had a previous history of epilepsy (Group I) and 398 (56.5%) had a first-time seizure and were considered to have symptomatic seizures (Group II). Multiple factors played roles in the development of seizures in 54.8% of the patients. In most patients, metabolic causes, systemic infections, and drug use were identified and an intracranial metastatic mass lesion was the major cause in patients with lung cancer. Rates of hypoxemia and respiratory acidosis were significantly higher in patients with symptomatic seizures (Group II) than in patients with primary epilepsy (Group I). Blood gas changes such as hypoxemia and respiratory acidosis were among the factors statistically associated with the development of symptomatic seizures in patients with respiratory diseases. Additionally, hypoxemia, hypercapnia, and respiratory acidosis were correlated with mortality in patients hospitalized for respiratory system diseases who requested consultations for seizures.

Holding up under pressure: a complex interplay between cerebral blood flow and ventilatory responses to alterations in carbon dioxide.

Holding up under pressure: a complex interplay between cerebral blood flow and ventilatory responses to alterations in carbon dioxide.

THE EFFECT OF ANESTHETIC TIME AND CONCENTRATION ON BLOOD GASES, ACID-BASE STATUS, AND ELECTROLYTES IN KOI (CYPRINUS CARPIO) ANESTHETIZED WITH BUFFERED TRICAINE METHANESULFONATE (MS-222).

Anesthesia is commonly employed in aquatic medicine to facilitate physical exams, diagnostics, and surgical interventions. Tricaine methanesulfonate (MS-222) is the most commonly used anesthetic for fish and is currently the only anesthetic approved by the US Food and Drug Administration Center for Veterinary Medicine for food-producing fish. Despite the frequency of anesthetic procedures in fish, anesthetic monitoring remains rudimentary in many facilities. This study evaluated the impact on blood gases, acid-base balance, and electrolytes in koi (Cyprinus carpio) anesthetized at concentrations of 100 mg/L and 150 mg/L MS-222. Blood samples from 25 fish per treatment were collected at 5 and 20 min of anesthetic immersion. Forty-nine of 50 fish recovered uneventfully from anesthesia; one fish did not recover and was euthanatized. Results showed significant increases in partial pressure of carbon dioxide (pCO2) (P = 0.006) and hyperglycemia (P = <0.0001) with increasing anesthetic concentration and time under anesthesia and a significant decrease in partial pressure of oxygen (pO2) with increased anesthetic time (P = 0.021). There were several electrolyte changes observed with both increasing anesthetic time and concentration. All electrolytes except potassium remained within published reference ranges for koi, while potassium showed a significant decrease in concentration associated with anesthetic time and concentration. The results of this study indicate that MS-222 at 100 mg/L and 150 mg/L represent safe anesthetic concentrations for koi undergoing minimally invasive diagnostics; however, koi anesthetized with MS-222 at a concentration of 150 mg/L experienced more significant changes in blood gases, acid-base balance, and electrolyte concentrations.

The comparison of tracheostomy and translaryngeal intubation regarding free radical formation and pulmonary effects.

Our aim in this study was to compare the blood gas changes, the malondialdehyde (MDA) and endogenous antioxidant glutathione (GSH) levels in blood and lung tissues after ischemia/reperfusion, the histopathological damage in lung tissue in rats provided respiratory support with mechanical ventilation after translaryngeal intubation and tracheostomy. Group 1 rats were provided mechanical ventilator support after translaryngeal intubation, Group 2 mechanical ventilator support after tracheostomy, and Group 3 was the control group where rats were only anesthetized. Three groups were compared for blood gas changes, MDA, GSH, and histopathological changes. Blood gas evaluation showed a more marked increase in pO2 values and decline in pCO2 values in Group 2 than Group 1 (p<0.05), and higher serum MDA levels in Group 1 than Group 2 (p<0.05). Tissue GSH levels in Groups 1 and 2 were higher than the control group, but this difference was not statistically significant (p>0.05). In terms of histopathological scoring, the damage score in Group 1 was higher than in Group 2 (p<0.05). This is the first study to show tracheostomy to be more advantageous than translaryngeal intubation in terms of blood gases, ischemia/reperfusion damage, and structural changes in the lung tissue.

Respiratory Drive in Critically Ill Patients. Pathophysiology and Clinical Implications.

Respiratory drive, the intensity of the respiratory center's output, determines the effort exerted in each breath. The increasing awareness of the adverse effects of both strong and weak respiratory efforts during mechanical ventilation on patient outcome brings attention to the respiratory drive of the critically ill patient. Critical illness can affect patients' respiratory drive through multiple pathways, mainly operating through three feedback systems: cortical, metabolic, and chemical. The chemical feedback system, defined as the response of the respiratory center's output to changes in arterial blood gases and pH, is one of the most important determinants of respiratory drive. The purpose of this state-of-the-art review is to describe the determinants of respiratory drive in critically ill patients, review the tools available to assess respiratory drive at the bedside, and discuss the implications of altered respiratory drive during mechanical ventilation. An analysis that relates arterial carbon dioxide levels with brain's response to this stimulus will be presented, contrasting the brain's responses to the patient's ability to generate effective alveolar ventilation, both during unassisted breathing and with different modes of ventilatory assist. This analysis may facilitate comprehension of the pathophysiology of respiratory drive in critically ill patients. As we aim to avoid both over- and under-assistance with mechanical ventilation, considering the patients' respiratory drive at the bedside may improve clinical assessment and management of the patient and the ventilator.

Effect of Retrograde Autologous Priming on Clinical Outcome of Cardiopulmonary Bypassing on Patients Undergoing Coronary Artery bypass Grafting

Introduction: Cardiopulmonary bypass is a standard and low mortality-associated method used across the world. This method allows cardiac surgery to be performed in a bloodless environment. The study aimed to compare Conventional priming and Retrograde autologous prime (RAP) on patients undergoing coronary artery bypass grafting (CABG).Methods: The study population was patients undergoing CABG using cardiopulmonary bypass in Rajaei Hospital, of whom 80 patients were selected by simple random sampling convenience sampling and then were randomly assigned to two groups: Conventional priming and RAP. Demographic information, blood components transfused in the operating room and the intensive care unit, ejection fraction (EF) of left ventricle and changes in blood gases were collect.Results: The mean requirement for red blood cell transfusion bags to the patient during surgery was lower in the RAP group than the conventional priming group (P = 0.002). But the difference after surgery in both groups was not significant statistically (P = 0.2). The difference amount of platelet transfusion during operation the difference was not statistically significant (P = 0.4). The difference postoperative platelet transfusion was not statistically significant (P = 0.7). The fresh frozen plasma transfusion during surgery in the RAP group lower than the usual prime group, but the difference was not statistically significant (P = 0.406). The Fresh frozen plasma (FFP) transfusion after surgery in the two groups was not statistically significant (P = 0.217).Conclusion: RAP is compared with conventional priming a safe and low-cost technique in reducing the priming volume of the CPB system, causes less hemodilution, and reduces the need for intra- and postoperative blood transfusion. Therefore, it is recommended to consider RAP as an effective and low-cost technique of priming Cardiopulmonary bypass circuits.

Association Between Arterial Blood Gas Variation and Intraocular Pressure in Healthy Subjects Exposed to Acute Short-Term Hypobaric Hypoxia.

PurposeTo investigate the association between changes in arterial blood gases and intraocular pressure (IOP) after acute, short-term exposure to simulated elevation of 4000 m above sea level.MethodsTwenty-five healthy young lowlanders participated in this prospective study. IOP was measured in both eyes with an Accupen tonometer. Arterial blood gas parameters (partial oxygen pressure [PaO2], partial carbon dioxide pressure [PaCO2], pH, and bicarbonate ion [HCO3−]) were checked using a blood gas analyzer. Measurements were taken at sea level (T1), at 15-minute (T2) and at 2-hour (T3) exposure times to simulated 4000 m above sea level in a hypobaric chamber, and upon return to sea level (T4). Associations between arterial blood gas parameters and IOP were evaluated using multivariate linear regression.ResultsPaO2 significantly decreased at T2 and T3, resolving at T4 (P < 0.001). pH significantly increased at T2 and returned to baseline at T3 (P = 0.004). Actual and standard bicarbonate ion both dropped with IOP at T3 and T4. IOP significantly decreased from 16.4 ± 3.4 mm Hg at T1 to 15.1 ± 2.1 mm Hg (P = 0.041) at T3 and remained lower (14.9 ± 2.4 mm Hg; P = 0.029) at T4. IOP was not correlated with pH. Multivariate linear regression showed that lower IOP was associated with lower standard bicarbonate ion (beta = −1.061; 95% confidence interval, −0.049 to −2.074; P = 0.04) when adjusted for actual bicarbonate and diastolic blood pressure.ConclusionsHypobaric hypoxia triggers plasma bicarbonate ion reduction which, rather than pH, may decrease aqueous humor formation and subsequently cause IOP reduction. These findings may shed light on the mechanism of IOP regulation at high altitude.Translational RelevanceHypoxia-triggered reduction in plasma bicarbonate ion may decrease aqueous humor production, leading to IOP reduction at high altitude. These findings may provide new insight into a potential mechanism of IOP regulation. Hypobaric hypoxia at high altitude is an environmental factor that can reduce IOP and, therefore, deserves further study.

Assessment of obstructive sleep apnoea (OSA) in children: an update.

SUMMARYOSA is a condition characterised by episodes of complete or partial obstruction of the upper airway, associated with blood-gas changes and atypical sleep patterns. Early diagnosis of OSA may reduce the occurrence of systemic complications over time, although the diagnosis of OSA is, unfortunately, often late. The aim of the work is to review the current concepts in evaluation of paediatric obstructive sleep apnoea (OSA), with an updated revision of the literature considering risk factors, clinical manifestations, and basic and advanced assessment in the paediatric population. For this narrative review, PubMed, Embase and Cinahl databases were searched for the last 10 years, according to PRISMA criteria/guidelines. Assessment of paediatric OSA remains challenging and paediatric patients should always be carefully evaluated; polysomnography is the gold standard for diagnosis of paediatric OSA.

The determination of treatment effect of chitosan oligosaccharide in lambs with experimentally cryptosporidiosis.

In this study, it was aimed to investigate the efficacy of chitosan oligosaccharide administrations in different doses of experimental infected lambs with Cryptosporidium parvum. 32 male lambs were used in the study and the lambs were divided into 4 groups with 8 lambs in each group. Groups 1, 2 and 3, twice a day, were administered chitosan oligosaccharide at a dose of 100, 500, and 1000 mg/kg for 7 days, respectively, with milk replacer. In group 4, lambs with cryptosporidiosis were subjected to normal feeding as control without drug administration. Clinical examinations of lambs were made before treatment (day 0) and on days 1, 3, 5 and 7 after treatment and 5 ml of blood was collected from vena jugularis for blood analysis of all lambs. Weight changes of lambs were recorded at 0, 7, 14, and 21 days. Stool specimens were collected pre-treatment (day 0) and on days 1, 3, 5, 7, 14 and 21 post-treatment to determine oocyst excretion of lambs with cryptosporidiosis. Lambs with a mean oocyte counts >10 after stool examination were included to the treatment. Changes in clinical hematology, blood gases and biochemical parameters were observed during the course of treatment, but these changes were limited. Weight loss was observed at 7th day according to 0th day the lambs with experimental cryptosporidiosis but gradually weight increase was observed at 14th and 21st days and these changes were similar in all groups. Oocyst excretion decreased in all groups during treatment. According to 0th day, there was a significant (p < 0.05) decrease in oocyte excretions in the third day in group 1 and 2, and in day 5 in the group 3 and 4. Significant changes (p < 0.05) were observed in oocyst excretions on the third and fifth days among the groups. As a result, in lambs with experimental cryptosporidiosis, chitosan oligosaccharide improved in clinical signs and stool character shorter than the positive control group and the administration of chitosan oligosaccharide at doses of 100, 500 and 1000 mg/kg for 7 days significantly reduced oocyst excretion but not enough to remove cryptosporidiosis completely.