The pressure gradient technique was used to evaluate effects of respiration on left ventricular stroke volume in 22 patients: 11 normal patients; eight patients with airway obstruction; and three patients with pericardial tamponade. In normals, stroke volume, systolic pressure, and pulse pressure fell an average of 7, 3 and 11% (P < 0.01), respectively, during inspiration. In patients with airw...

The pressure gradient technique was used to evaluate effects of respiration on left ventricular stroke volume in 22 patients: 11 normal patients; eight patients with airway obstruction; and three patients with pericardial tamponade. In normals, stroke volume, systolic pressure, and pulse pressure fell an average of 7, 3 and 11% (P < 0.01), respectively, during inspiration. In patients with airw...

To determine how the presence of generalised airflow limitation due to chronic obstructive lung disease affects the recognition of simulated upper airway obstruction, a study was carried out in 12 patients (mean (SD) age 57 (7) years) with chronic obstructive lung disease (FEV1% predicted 53 (22), range 21-70) and 12 matched control subjects. Patients and control subjects performed maximal insp...

The performance of the Pneupac Ventipac portable gas-powered ventilator was evaluated in two stages. The accuracy of delivery of the ventilator was assessed using a mechanical lung model at different combinations of compliance and airway resistance to simulate normal and diseased lungs. The performance of the ventilator was then assessed in 20 anaesthetized patients. The tidal volume delivered ...

The study was undertaken to assess the airway function and its response to carbachol and salbutamol in infants recovering from wheezy bronchitis. In 82 children aged 3-33 mths, free from wheeze at the time of testing, and in 14 healthy infants, airway resistance (Raw) and thoracic gas volume (TGV) were measured using a body plethysmograph. Specific airway resistance (sRaw = Raw x TGV) was calcu...

When airway smooth muscle is contracted in vitro, the airway lumen continues to narrow with increasing concentrations of agonist until complete airway closure occurs. Although there remains some controversy regarding whether airways can close in vivo, recent work has clearly demonstrated that, if the airway is sufficiently stimulated with contractile agonists, complete closure of even large car...

BACKGROUND Single lung transplantation (SLT) is now a treatment option for patients with both pulmonary fibrosis and advanced chronic airway obstruction. Lung function after transplantation might be expected to be different in these two groups of patients because of the effect of the remaining native lung, but the implications of these differences have not been fully explored. METHODS The fun...

STUDY OBJECTIVE Bag-valve-mask ventilation remains an essential component of airway management. Rescuers continue to use both traditional 1- or 2-handed mask-face sealing techniques, as well as a newer modified 2-handed technique. We compare the efficacy of 1-handed, 2-handed, and modified 2-handed bag-valve-mask technique. METHODS In this prospective, crossover study, health care providers p...

BACKGROUND It is standard practice to administer a cholinesterase inhibitor (e.g., neostigmine) at the end of a surgical case to reverse suspected effects of neuromuscular blocking agents regardless of whether such residual effects are present. The authors hypothesized that cholinesterase inhibition when given the in absence of neuromuscular blockade (NB) would decrease upper airway dilatory mu...

Background When imaging the airway by MRI, the traditional technique turbo spin echo (TSE) results in high quality 2D images of the airway. However, planning and acquisition times are often lengthy. An alternative technique for airway image acquisition, delayed volume interpolated breath hold examination or VIBE, is a 3D gradient echo technique that produces high spatial resolution imaging of t...