Concomitant ventilatory and circulatory functions of the diaphragm and abdominal muscles.

Expulsive maneuvers (EMs) caused by simultaneous contraction of diaphragm and abdominal muscles shift substantial quantities of blood from the splanchnic circulation to the extremities. This suggests that the diaphragm assisted by abdominal muscles might accomplish ventilation and circulation simultaneously by repeated EMs. We tested this hypothesis in normal subjects by measuring changes (Δ) in body volume (Vb) by whole body plethysmography simultaneously with changes in trunk volume (Vtr) by optoelectronic plethysmography, which measures the same parameters as whole body plethysmography plus the volume of blood shifts (Vbs) between trunk and extremities: Vbs = ΔVtr-ΔVb.

A multicenter, prospective study of a novel nasal EPAP device in the treatment of obstructive sleep apnea: efficacy and 30-day adherence.

Study Objectives: Evaluate the efficacy of a novel device placed in the nares that imposes an expiratory resistance for the treatment of obstructive sleep apnea (OSA) and evaluate adherence to the device over a 30-day in-home trial period.

Design: One diagnostic and 3 treatment polysomnograms were administered in a Latin-square design to identify the optimal expiratory resistance to be used during the 30-day in-home trial. Subjects had repeat polysomnography with the prescribed device at the end of the 30-day trial.

A prospective feasibility study of bronchial thermoplasty in the human airway.

Background: Bronchial thermoplasty is a novel procedure being developed as a potential treatment for asthma. Experience with animal studies has enabled development of appropriate reliable equipment, definition of therapeutic parameters, and descriptions of tissue effects of treatment.

Study Objectives: This study was undertaken to assess the feasibility and general safety of the application of bronchial thermoplasty in the human airway, and to determine if the reduction in airway smooth muscle seen in animal studies could be replicated.

Reduction in airway hyperresponsiveness to methacholine by the application of RF energy in dogs.

We delivered controlled radio frequency energy to the airways of anesthetized, ventilated dogs to examine the effect of this treatment on reducing airway narrowing caused by a known airway constrictor. The airways of 11 dogs were treated with a specially designed bronchial catheter in three of four lung regions. Treatments in each of the three treated lung regions were controlled to a different temperature (55, 65, and 75 degrees C); the untreated lung region served as a control.