1. A surface electrode was used to record electromyographic activity of the posterior cricoarytenoid muscle during breathing in normal subjects and patients with airflow obstruction. 2. Phasic activity of the posterior cricoarytenoid muscle was demonstrated. This was present on inspiration and absent on expiration. 3. Phasic inspiratory activity in normal subjects was present only during period...

BACKGROUND Vocal cord dysfunction (VCD) is difficult to diagnose. Laryngoscopy while the patient is symptomatic is the accepted standard method to establish a diagnosis of VCD, but patient characteristics and spirometry values are thought to be useful for predicting VCD. We sought to identify clinical and spirometric variables that suggest VCD. METHODS We performed 2 parallel studies. First, ...

SUBJECT OBJECTIVE To assess the hemodynamic effects of manual lung hyperinflation in mechanically ventilated patients and to measure the different inspiratory pressures and tidal volumes generated by different operators. DESIGN Measurements of aortic blood flow (by esophageal Doppler ultrasonography), systemic blood pressure, tidal volumes (by respirometry), and inspiratory pressures in the v...

The purpose of this study was to extend previous observations of a greater decrease in tidal volume in infants than in children during halothane anaesthesia. We analyzed the inspiratory flow waveform recorded during spontaneous ventilation in: infants, two to six months of age, and children, one to five years of age. In addition we analyzed the CO2 signal and the pressure waveform during an occ...

Mechanically, breath design is usually either flow/volume-targeted or pressure-targeted. Both approaches can effectively provide lung-protective ventilation, but they prioritize different ventilation parameters, so their responses to changing respiratory-system mechanics and patient effort are different. These different response behaviors have advantages and disadvantages that can be important ...

BACKGROUND To increase the sensitivity of measurements of maximal inspiratory pressure (MIP) as a test of inspiratory muscle strength and endurance, software was developed to correct for variation in lung volume. METHODS Using a body plethysmograph to determine absolute lung volume during each manoeuvre, values for MIP were expressed as a percentage of the pressure "expected" from the unfatig...

To assess the relationship of abnormal flow-volume curves during awake periods to the clinical severity of sleep-disordered breathing and the need for surgical treatment of obstructive sleep apnoea, flow-volume curves were measured in 72 adults with obstructive apnoea. Patients in whom surgery was recommended for standard clinical indications had significantly lower inspiratory flow rates (p le...

P SPIROMETRY VERSUS FLOW VOLUME INSPIRATORY AND EXPIRATORY LOOP To the Editor: I would like to comment on the excellent CME article, “Vocal Cord Dysfunction: An Update” by Leslie M. Gimenez, MD, and Heidi Zafra, MD (Ann Allergy Asthma Immunol. 2011;106:267–275). I compliment the authors on the very thorough review and analysis of the literature. I am concerned by the nomenclature they used in d...

background: postoperative pulmonary dysfunction is one of the most frequent complications after cardiac surgery and it is believed to result from the use of cardiopulmonary bypass (cpb). in this study, we investigated the effect of low tidal volume ventilation during cpb on postoperative gas exchange and lung mechanics. methods: this prospective randomized study included 100 patients undergoing...

BACKGROUND While inspiratory muscle weakness is common in prolonged mechanical ventilation, inspiratory muscle strength training (IMST) can facilitate strengthening and ventilator weaning. However, the inspiratory load compensation (ILC) responses to threshold loads are not well characterized in patients. We retrospectively compared ILC responses according to the clinical outcomes of IMST (ie, ...