arterial blood gases

BACKGROUND: The need for a horse to be ridden while wearing a measurement device that allows unrestricted ventilation and gas exchange has hampered accurate measurement of its maximal oxygen consumption (V̇O2 max) under field conditions. OBJECTIVES: Design and validate a facemask with the potential to accurately measure V̇O2 max in the field. STUDY DESIGN: Experiment with 6 x 6 Latin square design. METHODS: Two variations of a mask and associated electronic control module (ECM) were designed to enable breath-by-breath measurement of airflows through two 7...

OBJECTIVE: To investigate the optimal injury time point of cardiac arrest (CA) induced electrically, and establish a reproducible prolonged CA and cardiopulmonary resuscitation (CPR) model in pigs. METHODS: Forty healthy domestic male pigs were randomly divided into four groups, which were ventricular fibrillation (VF) 8, 10, 11, and 12 minutes groups, each group for 10 animals. In these groups, VF was induced by alternating current delivered to right ventricular endocardium and untreated for 8, 10, 11, and 12 minutes, respectively, followed by 6 minutes of CPR procedure...

OBJECTIVE: To record the cardiopulmonary effects of pleural CO2 positive pressure insufflation in anesthetized horses. STUDY DESIGN: Prospective study. ANIMALS: Seven horses (mean ± standard deviation, 530.9 ± 68.1 kg) undergoing terminal surgery. METHODS: Horses were sedated with xylazine. Anesthesia was induced with ketamine-propofol and maintained with isoflurane, positive pressure ventilation, detomidine infusion, and butorphanol with the horses in dorsal recumbency...

The arterial partial pressure of carbon dioxide (PaCO2) is an important parameter in critically ill, mechanically ventilated patients. To limit invasive procedures or for more continuous monitoring of PaCO2, clinicians often rely on venous blood gases, capnography, or transcutaneous monitoring. Each of these has advantages and limitations. Central venous Pco2 allows accurate estimation of PaCO2, differing from it by an amount described by the Fick principle. As long as cardiac output is relatively normal, central venous Pco2 exceeds the arterial value by approximately 4 mm Hg...

BACKGROUND: ARDS is characterized by decreased functional residual capacity (FRC), heterogeneous lung injury, and severe hypoxemia. Tidal ventilation is preferentially distributed to ventilated alveoli. Aerosolized prostaglandin I2 exploits this pathophysiology by inducing local vasodilation, thereby increasing ventilation-perfusion matching and reducing hypoxemia. Therefore, aerosolized prostaglandin I2 efficacy may depend upon FRC. Both PaO2 /FIO2 and compliance of the respiratory system (CRS) are indirect signifiers of FRC and thus may partly determine the response to aerosolized prostaglandin I2...

OBJECTIVE: To assess the diagnostic accuracy of peripheral capillary oxygen saturation (SpO2) while breathing room air for 5 min (the 'Air-Test') in detecting postoperative atelectasis. DESIGN: Prospective cohort study. Diagnostic accuracy was assessed by measuring the agreement between the index test and the reference standard CT scan images. SETTING: Postanaesthetic care unit in a tertiary hospital in Spain. PARTICIPANTS: Three hundred and fifty patients from 12 January to 7 February 2015; 170 patients scheduled for surgery under general anaesthesia who were admitted into the postsurgical unit were included...

OBJECTIVE: We investigated the plasma concentrations and cardiovascular effects of intramuscularly (IM) administered medetomidine, administered alone or with three different doses of MK-467. STUDY DESIGN: Prospective, randomized, open, crossover trial. ANIMALS: Eight purpose-bred healthy Beagle dogs. METHODS: Each dog was administered four treatments: medetomidine 20 μg kg(-1) IM alone or mixed in the same syringe with MK-467 (200 μg kg(-1), 400 μg kg(-1) or 600 μg kg(-1))...

OBJECTIVES: In the contemporary ICU, mechanically ventilated patients may not have arterial blood gas measurements available at relevant timepoints. Severity criteria often depend on arterial blood gas results. Retrospective studies suggest that nonlinear imputation of PaO2/FIO2 from SpO2/FIO2 is accurate, but this has not been established prospectively among mechanically ventilated ICU patients. The objective was to validate the superiority of nonlinear imputation of PaO2/FIO2 among mechanically ventilated patients and understand what factors influence the accuracy of imputation...

While pathophysiology underlying post-concussion symptom burden is unknown, data suggest that cerebrovascular dysfunction may be among the culprits. We sought to determine whether the degree of impairment in the ability of cerebrovasculature to buffer against changes in arterial gases (vasoreactivity) is associated with concussion symptoms. In 15 participants (19±5 years, 1 week to 1 year post-injury) diagnosed with concussion, we assessed vasoreactivity from the slope of the linear relationship of beat-by-beat middle cerebral artery blood flow velocity (transcranial Doppler ultrasound) to end-tidal CO₂ during progressive increases in end-tidal CO₂ (air rebreathing)...

The human cardiovascular system (CVS) and respiratory system (RS) work together in order to supply oxygen (O2) and other substrates needed for metabolism and to remove carbon dioxide (CO2). Global and local control mechanisms act on the CVS in order to adjust blood flow to the different parts of the body. This, in turn, affects the RS since the amount of O2 and CO2 transported, respectively to and away from the tissues depends on the cardiac output and blood flow in both the systemic and pulmonary circuits of the CVS...

Reducing the work of breathing or eliminating exercise-induced arterial hypoxemia (EIAH) during exercise decreases the severity of quadriceps fatigue in men. Women have a greater work of breathing during exercise, dedicate a greater fraction of whole-body V̇O2 towards their respiratory muscles, and demonstrate EIAH, suggesting women may be especially susceptible to quadriceps fatigue. Healthy subjects (8M, 8F) completed three constant load exercise tests over four days. During the first (control) test, subjects exercised at ∼85% of maximum while arterial blood gases and work of breathing were assessed...

Study Objectives: Sudden unexpected death during sleep (SUDS) is the most common cause of death in patients with familial dysautonomia, an autosomal recessive disease characterized by sensory and autonomic dysfunction. It remains unknown what causes SUDS in these patients and who is at highest risk. We tested the hypothesis that SUDS in FD is linked to sleep-disordered breathing. Methods: We retrospectively identified patients with familial dysautonomia who died suddenly and unexpectedly during sleep and had undergone polysomnography within the 18-month period prior to death...

Lung ischemia-reperfusion injury remains a major complication after lung transplantation. Variable ventilation (VV) has been shown to improve respiratory function and reduce pulmonary histological damage compared to protective volume-controlled ventilation (VCV) in different models of lung injury induced by endotoxin, surfactant depletion by saline lavage, and hydrochloric acid. However, no study has compared the biological impact of VV vs. VCV in lung ischemia-reperfusion injury, which has a complex pathophysiology different from that of other experimental models...

INTRODUCTION: Arterial blood sampling, used to assess patients in acute conditions, may result in complications such as thrombosis and embolism. However, it can be replaced by venous blood sampling, but there is a dearth of information on this. AIM: To assess the correlation and agreement between the arterial and central venous blood gases analyses in patients undergoing elective Coronary Artery Bypass Graft (CABG) surgery. MATERIALS AND METHODS: In this cross-sectional study, 100 ICU patients undergoing elective CABG surgery were recruited...

Objective: To evaluate the impact of CO(2) pneumoperitoneum in operating rooms on the health of medical staffs. Methods: In June 2016, the thirty-three medical staffs in operating rooms were chosen as the object of the research.Seventeen people who took part in the pneumoperitoneum operation were selected as a exposure group and sixteen people who took part in the laparotomy operation were selected as a control group.Vital signs and arterial blood gases of medical staffs in the two groups were both measured in pre-operation and post-operation...

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a progressive pulmonary disease caused by harmful gases or particles. Recent studies have shown that 2% hydrogen or hydrogen water is effective in the treatment and prevention of a variety of diseases. This study investigated the beneficial effects and the possible mechanisms of different hydrogen concentrations on COPD. METHODS: A rat COPD model was established through smoke exposure methods, and inhalation of different concentrations of hydrogen was used as the intervention...

High-intensity non-invasive positive pressure ventilation (NPPV) was originally described for chronic hypercapnic chronic obstructive pulmonary disease (COPD) patients in 2009, and refers to a specific ventilatory approach whereby NPPV settings are aimed at achieving the lowest arterial partial pressure of carbon dioxide (PaCO2) values possible. Thus, high-intensity NPPV requires ventilator settings to be increased in a stepwise approach to either an individually tolerated maximum, or to the levels necessary to achieve normocapnia...

BACKGROUND: Maintenance of brain circulation during shock is sufficient to prevent subcortical injury but the cerebral cortex is not spared. This suggests area-specific regulation of cerebral blood flow (CBF) during hemorrhage. METHODS: Cortical and subcortical CBF were continuously measured during blood loss (≤50%) and subsequent reperfusion using laser Doppler flowmetry. Blood gases, mean arterial blood pressure (MABP), heart rate and renal blood flow were also monitored...

The present study investigated the protective effects of small ubiquitin-like modifier 1 (SUMO-1) on spinal cord ischemic damage in rabbits. A trans‑activator of transcription (Tat)‑SUMO‑1 fusion protein was prepared, and transient spinal cord ischemia was induced by occlusion of the abdominal aorta for 15 min. Vehicle (glycerol) or 1 mg/kg Tat-1-SUMO‑1 was administered intraperitoneally to the rabbits immediately following ischemia/reperfusion. Administration of Tat-SUMO-1 did not lead to significant alterations in arterial blood gases [partial pressure (Pa)CO2 and PaO2], pH, or blood glucose levels prior to ischemia, 10 min after occlusion or 10 min after reperfusion...

BACKGROUND: The influence of the recombinant form of human relaxin-2 (serelaxin) on pulmonary hemodynamics under physiologic conditions have not been the subject of studies in an animal model up until now. METHODS: We therefore utilised the large animal model sheep, convenient in its similar cardiovascular physiology, to investigate said influence. All animals underwent right heart catheterization, a safe and reliable invasive procedure for the assessment of pulmonary hemodynamics, and then received either 30μg/kg serelaxin (n = 11) or saline (n = 13)...