Ten patients with known but clinically stable chronic obstructive pulmonary disease (COPD) were studied while breathing low-flow (1-2 L/min) supplemental oxygen by nasal cannula and by biflow nasal mask. Although the increase in inspired oxygen when breathing with the cannula has been documented, the nasal mask has not been tested by measurement of PaO2 change. The mean age of the group was 64.6 years, and their mean PaO2 was 54 ± 10.5 torr while they were at rest and breathing room air. Patients were each given oxygen alternately with the mask and cannula, with no change in flowrate; time was allowed between the two for equilibration and return to baseline values. PaO2 values were compared by t test for nonindependent samples, which provided a t value of 1.893, with P = 0.09. Differences in measured arterial saturation (SaO2) and PaCO2 also proved to be insignificant when patients breathed via the two devices. We conclude that the nasal cannula and the biflow nasal mask produce comparable PaO2 in patients who may need low-flow supplemental oxygen at rest. The mask can be considered an alternative oxygen appliance if preferred by patients because of comfort. (Respir Care 1985;30:250-255.)
Differentiating the Course of Symptom Improvement Between Two Treatments for Childhood Anxiety Disorders
ABSTRACT Objectives Cognitive behavioral therapy (CBT) is the most researched treatment for childhood anxiety disorders (CADs). Improving outcomes and efficiency of CBT will require identifying and optimizing the most efficacious therapeutic components. Towards this end, a recent randomized controlled trial (RCT) found that Parent Coached Exposure Therapy (PCET) led to greater symptom improvement in less time than traditional CBT. To better understand and maximize these advantages, the current study explores the timing and course of symptom improvement in these two treatments for CADs, CBT, and PCET. Methods In this secondary analysis of data from the RCT, 56 youth aged 7−17 years (73.2% female) and a parent provided weekly ratings of anxiety symptom severity. Results The mean anxiety severity ratings decreased significantly in both conditions, but a significant condition by time interaction suggested that the pace of change differed between treatment for parent report, F (6.2, 335) = 2.96, p = 0.007. A series of post‐hoc comparisons indicated that the ratings became significantly lower in the PCET group beginning in session 3 (effect size = 0.77) through post‐treatment assessment. In addition, within each treatment condition the largest change in severity ratings occurred after the introduction of exposure, effect sizes of 0.68 for PCET and 0.56 for CBT. The child severity ratings followed a similar pattern but did not reach statistical significance. Discussion The implications of these exploratory and hypothesis‐generating findings for designing treatment protocols to deliver exposure in a manner to maximize the amount, and pace, of improvement are discussed.
Some Effects of Anesthetics and the Anesthetized State on the Respiratory System
Pneumotachographs (also called pneumotachometers and anemometers) measure airflow against a fixed resistance and may be found in respirometers, mechanical ventilators, incentive breathing devices, diagnostic spirometers, and other pulmonary function testing instruments. The Fleisch design is the oldest, but it requires a costly pressure transducer and analog-to-digital converter and its accuracy is affected by gas-viscosity differences and by airflow turbulence. Besides the Fleisch, ceramic, screen, orifice, hot-wire, turbine, vortex, and ultrasonic pneumotachographs are now available. They solve some of the Fleisch's problems but cannot be used in all applications. All instruments with these devices must be carefully and completely calibrated at the time of installation and routinely calibrated or checked thereafter.
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The Use of the Chest Cuirass in Respiratory Failure of Neurologic Origin
Three patients with different neurologic diseases—amyotrophic lateral sclerosis, poliomyelitis, and idiopathic bilateral diaphragm paralysis—and with chronic ventilatory failure were successfully ventilated with negative pressure. This noninvasive ventilatory technique uses a chest cuirass and provides an alternative to tracheostomy and positive-pressure ventilation. As a result of the benefits that these three patients received, we conclude that the cuirass remains an acceptable method of ventilation for some patients with chronic neurologic disease.