arterial blood gases

BACKGROUND: Lethal influenza A (H5N1) induces respiratory failure in humans. Although it also causes death at 7 day postinfection (dpi) in mice, the development of the respiratory failure and the viral impact on pre-Botzinger complex (PBC) neurons expressing neurokinin 1 receptor (NK1R), the respiratory rhythm-generator, have not been explored. METHODS: Body temperature, weight, ventilation, arterial blood pH and gases were measured at 0, 2, 4, and 6 dpi in control, lethal HK483 and non-lethal HK486 viral infected mice...

BACKGROUND: Bariatric surgery has proven a successful approach in the treatment of morbid obesity and its concomitant diseases such as diabetes mellitus and arterial hypertension. Aiming for optimal management of this challenging patient cohort, tailored concepts directly guided by individual patient physiology may outperform standardized care. Implying esophageal pressure measurement and electrical impedance tomography-increasingly applied monitoring approaches to individually adjust mechanical ventilation in challenging circumstances like acute respiratory distress syndrome (ARDS) and intraabdominal hypertension-we compared our institutions standard ventilator regimen with an individually adjusted positive end expiratory pressure (PEEP) level aiming for a positive transpulmonary pressure (P L) throughout the respiratory cycle...

BACKGROUND: Non-invasive ventilation (NIV) with bi-level positive airway pressure (BiPAP) is commonly used to treat patients admitted to hospital with acute hypercapnic respiratory failure (AHRF) secondary to an acute exacerbation of chronic obstructive pulmonary disease (AECOPD). OBJECTIVES: To compare the efficacy of NIV applied in conjunction with usual care versus usual care involving no mechanical ventilation alone in adults with AHRF due to AECOPD. The aim of this review is to update the evidence base with the goals of supporting clinical practice and providing recommendations for future evaluation and research...

BACKGROUND: The use of resuscitative endovascular balloon occlusion as a maneuver for occlusion of the aorta is well described. This technique has life-saving potential in other cases of traumatic hemorrhage. Retro-hepatic inferior vena cava (IVC) injuries have a high rate of mortality, in part, due to the difficulty in achieving total vascular isolation. This studies purpose was to investigate the ability of resuscitative balloon occlusion of the IVC (REBOVC) to control supra-hepatic IVC hemorrhage in a swine model of trauma...

BACKGROUND: Flexible bronchoscopy (FB) in intubated patients on mechanical ventilation increases airway resistance. During FB, two ventilatory strategies are possible: maintaining tidal volume (VT) while maintaining baseline CO2 or allowing reduction of VT. The former strategy carries risk of hyperinflation due to expiratory flow limitation with FB. The aim of the authors was too study end expiratory lung volume (EELV) during FB of intubated subjects while limiting VT. METHODS: We studied 16 subjects who were intubated on mechanical ventilation and required FB...

The effects of acute hypoxia have been widely studied, but there are few studies of transcriptional responses to hours of hypoxia in vivo, especially in hypoxia-tolerant tissues like skeletal muscles. We used RNA-seq to analyse gene expression in plantaris muscles while monitoring respiration, arterial blood gases, and blood glucose in mice exposed to 8% O2 for 2 or 6 h. Rapid decreases in blood gases and a slower reduction in blood glucose suggest stress, which was accompanied by widespread changes in gene expression...

BACKGROUND: Noninvasive ventilation (NIV) is generally delivered using pneumatically-triggered and cycled-off pressure support (PSP) through a mask. Neurally adjusted ventilatory assist (NAVA) is the only ventilatory mode that uses a non-pneumatic signal, i.e., diaphragm electrical activity (EAdi), to trigger and drive ventilator assistance. A specific setting to generate neurally controlled pressure support (PSN) was recently proposed for delivering NIV by helmet. We compared PSN with PSP and NAVA during NIV using a facial mask, with respect to patient comfort, gas exchange, and patient-ventilator interaction and synchrony...

BACKGROUND: Crystalloids are used routinely for perioperative fluid management in cesarean delivery. Few studies have determined the crystalloid of choice in obstetric anesthesia. We compared the effects of Ringer's lactate (RL) versus 0.9% normal saline (NS) on maternal and neonatal blood pH and 24-hour postoperative morbidity in urgent cesarean delivery in a low-resource setting. Our hypothesis was that RL would result in 30% less acidosis than NS. METHODS: This was a pragmatic prospective double-blind randomized controlled trial in the Mulago National Referral Hospital Labor Ward Theater from September 2011 to May 2012...

The primary aim was to explore the safety and tolerability of inhaled treprostinil when used in patients with pulmonary hypertension (PH) with concomitant chronic obstructive pulmonary disease (COPD). Patients with a diagnosis of pre-capillary PH (defined as pulmonary artery mean pressure of ≥ 25 mmHg and pulmonary artery wedge pressure or left ventricular end diastolic pressure of ≤ 15 mmHg) who were being initiated on inhaled treprostinil and had concomitant COPD (defined as FEV1/FVC ratio ≤ 70% with FEV1 ≥ 40% predicted) were considered for inclusion in this pilot study...

BACKGROUND: There is an equipoise regarding closed-loop ventilation modes and the ability to reduce workload for providers. On one hand some settings are managed by the ventilator but on another hand the automatic mode introduces new settings for the user. METHODS: This randomized controlled trial compared the number of manual ventilator setting changes between a full closed loop ventilation and oxygenation mode (INTELLiVENT-ASV®) and conventional ventilation modes (volume assist control and pressure support) in intensive care unit (ICU) patients...

OBJECTIVES: To compare 2 different ventilatory strategies: pressure-regulated volume-controlled (PRVC) versus volume-controlled ventilation during thoracotomy. DESIGN: Prospective randomized study. SETTING: University hospital. PARTICIPANTS: The study comprised 70 adult patients undergoing thoracic surgery. INTERVENTIONS: Evaluation of oxygenation parameters, airway pressures, and immune modulation...

PURPOSE: To test the hypothesis that poor brain tissue oxygenation (BtO2) during the first 24h of critical illness correlates with the proportion of time spent delirious. We also sought to define the physiological determinants of BtO2. MATERIALS AND METHODS: Adult patients admitted to the ICU within the previous 24h were considered eligible for enrollment if they required mechanical ventilation, and/or vasopressor support. BtO2 was measured using near-infrared spectroscopy, for 24h after enrollment...

BACKGROUND: Obstructive sleep apnea is characterized by intermittent hypoxia and hypercapnia. CO2 production, transport and elimination are influenced by the carbonic anhydrase enzyme. We hypothesized that elevated standard bicarbonate, a proxy for increased carbonic anhydrase activity, is associated with apnea severity and higher blood pressure in patients with obstructive sleep apnea. METHODS: A retrospective analysis of a sleep apnea cohort (n = 830) studied by ambulatory polygraphy...

Minimal advances have been made in the management of pulmonary contusions (PCs). The purpose of this study was to evaluate the impact of cyclooxygenase inhibition on outcomes following PC in a rat model. PC was induced in anesthetized adult rats. Ibuprofen was given to the treatment group (TG) and water was given to the control group (CG). Lung injury was assessed with pulse oximetry, arterial blood gases, CT, and histopathologic examination. Inflammation was measured with both serum and bronchoalveolar lavage (BAL) levels of tumor necrosis factor α and interleukin-6...

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...