Search results for "tilat"
showing 10 items of 730 documents
MRI in lung transplant recipients using hyperpolarized 3He: comparison with CT.
2002
PURPOSE To elucidate the ability of 3He-MRI to detect ventilation defects in lung transplant recipients, 3He-MRI was compared to CT for concordance. MATERIALS AND METHODS We examined 14 lung recipients using 3He-MRI on a 1.5 T MR scanner. CT served as a reference method. Up to four representative ventilation defects were defined for each lung on 3He-MRI and compared to corresponding areas on CT. RESULTS Altogether, 59 representative ventilation defects were defined on 3He-MRI. Plausible CT correlates were found for 29 ventilation defects; less plausible CT correlates were found for eight defects. In 22 defects (37%) no corresponding CT changes were detected. CT demonstrated correlates for v…
Electromyographic activity related to aerobic and anaerobic threshold in ergometer bicycling
1985
Electromyographic activity (EMG) of the knee extensor musculature (m. vastus lateralis, m. vastus medialis, m. rectus femoris), triceps surae (m. gastrocnemius, m. soleus) and m. tibialis anterior was studied in ergometer bicycling at five different power outputs around aerobic (AerT) and anaerobic (AnT) thresholds. EMGs were sampled with surface electrodes for ten revolutions at the beginning, in the middle and at the end of each work load and integrated (IEMG) separately for each of the muscles and for the descending (work) and ascending (rest) phase of the revolution. The mean power frequency (MPF) of the power spectral density function for the descending periods was also calculated. The…
Prevalence of Hyperventilation Syndrome in Patients Treated for Asthma in a Pulmonology Clinic
2005
Objective Although the presence of hyperventilation syndrome can affect the symptoms of patients with asthma, there is very little information available regarding its frequency in Spain. The aim of this study was to investigate the prevalence of hyperventilation syndrome in the asthmatic population treated as outpatients and establish its relationship with anxiety disorders. Patients and methods We studied 157 consecutive asthmatic patients (61 men and 96 women; mean [SD] age, 45 [17] years; forced expiratory volume in the first second, 84% [21%] of the predicted value) treated in our outpatients clinic. The patients had stable disease with varying degrees of severity. After collecting demo…
Effects of voluntary changes in breathing frequency on respiratory comfort
1998
Previous experiments on voluntary breathing have suggested that spontaneous breathing is partly determined by the minimization of respiratory sensations. However, during instructed breathing, respiratory sensations may be confounded with difficulty in achieving the prescribed pattern. In the present experiment, we tested the hypothesis that the subjective assessment of respiratory comfort and the difficulty in following breathing instructions are closely related. A total of 15 subjects adjusted breathing frequency to prescribed values ranging from 40 to 250% of individual spontaneous levels. Then, they scored the difficulty of this task and the discomfort associated with the target frequenc…
Human corticotropin-releasing factor (hCRF) is a potent respiratory analeptic. Physiological and clinical aspects.
1986
During intravenous corticotropin-releasing factor stimulation tests we observed a deepening of the tidal volume in 35 patients. To investigate this presumed respiratory stimulation we measured respiratory parameters in 12 healthy male volunteers in a single-blind placebo-controlled trial. The intravenous 60-s infusion of 100 micrograms of human corticotropin-releasing factor induced a very potent respiratory stimulation in every subject: respiratory minute volume (mean +/- S.D.) increased by 81% from 6.319 +/- 0.577 to 11.464 +/- 1.264 liters per min (P less than 0.001), whereas there was only a slight rise in the mean respiratory rate from 12.4 +/- 3.0 to 14.7 +/- 2.7 breaths per min (P le…
Quantifying training intensity distribution in a group of Norwegian professional soccer players.
2011
Purpose:This study was designed to quantify the daily distribution of training intensity in a group of professional soccer players in Norway based on three different methods of training intensity quantification.Methods:Fifteen male athletes (age, 24 ± 5 y) performed treadmill test to exhaustion to determine heart rate and VO2 corresponding to ventilatory thresholds (VT1, VT2), maximal oxygen consumption (VO2max) and maximal heart rate. VT1 and VT2 were used to delineate three intensity zones based on heart rate. During a 4 wk period in the preseason (N = 15), and two separate weeks late in the season (N = 11), all endurance and on-ball training sessions (preseason: N = 378, season: N= 78) w…
Management of Pneumothoraces Detected on Chest Computed Tomography: Can Anatomical Location Identify Patients Who Can Be Managed Expectantly?
2014
Abstract Background Pneumothorax (PTX) can be readily detected by computed tomography (CT) or ultrasound. However, management of PTX in hemodynamically stable patients remains controversial. Study Objectives We sought to investigate whether a distinct anatomical distribution of PTX along prespecified chest zones as detected by CT can be described in patients with or without subsequent chest tube thoracotomy (CTT), thus potentially allowing the extended focused assessment with sonography for trauma (EFAST) ultrasound examination to guide PTX management. Methods We performed a retrospective review of chest CT scans performed in the emergency department (ED) of a Level I trauma center. CT scan…
Association between night-time extubation and clinical outcomes in adult patients
2021
Background: Whether night-time extubation is associated with clinical outcomes is unclear. Objective: The aim of this systematic review and meta-analysis was to evaluate the association between night-time extubation and the reintubation rate, mortality, ICU and in-hospital LOS in adult patients, compared with daytime extubation. Design: A systematic review and meta-analysis. Data sources: PubMed, EMBASE, CINAHL and Web of Science from inception to 2 January 2021 (PROSPERO registration - CRD42020222812). Eligibility criteria: Randomised, quasi and cluster randomised, and nonrandomised studies describing associations between adult patients' outcomes and time of extubation (daytime/night-time)…
High-flow nasal cannula versus non-invasive ventilation for acute hypercapnic respiratory failure in adults: a systematic review and meta-analysis of…
2022
Abstract Background Non-invasive ventilation (NIV) with bi-level positive pressure ventilation is a first-line intervention for selected patients with acute hypercapnic respiratory failure. Compared to conventional oxygen therapy, NIV may reduce endotracheal intubation, death, and intensive care unit length of stay (LOS), but its use is often limited by patient tolerance and treatment failure. High-flow nasal cannula (HFNC) is a potential alternative treatment in this patient population and may be better tolerated. Research question For patients presenting with acute hypercapnic respiratory failure, is HFNC an effective alternative to NIV in reducing the need for intubation? Methods We sear…
Trainability of underwater breath-holding time.
1984
From diving practice we know that breath-holding time (BHT) can be increased by training. This examination was set up to illuminate whether BHT underwater can be trained decisively in a short period of time. The authors investigated whether physiologic or psychological aspects are the main constituents of the above-mentioned BHT phenomenon. BHT and the "onset point" of involuntary respiratory movements of 64 subjects were registered after deep inspiration and immersion in ca. 1 m. Two different tests were set up: (I) 2 breath-holds per day on 5 consecutive days, (II) 5 repeated breath-holds with pauses of 3 min in between. BHT of the first test was shorter underwater than in similar experim…