In their editorial on the pulmonary consequences ofillicit drug use (November 1995; 50:1125-7) Benson and Bentley draw attention to barotrauma as a complication of cocaine inhalation. Pneumothorax, pneumomediastinum, and pneumopericardium have also been described, however, in association with the use of marijuana,12 a drug that is more widely used in England and Australia than cocaine. The mech...

A two-year-old girl presents with repetitive episodes of facial cyanosis with occasional collapse. The episodes last for less than a minute and occur up to three times a day. She makes a rapid recovery after each episode and her mother states that the episodes are worse when Chloe is tired, irritable or does not get her own way. Her physical examination and past medical history is unremarkable....

Fourteen psychophysiological indices of response to hyperventilation and breathholding and to discrimination-conflict stress were combined with measures of neuroticism, motivation, and aptitude to form a correlation matrix including adjustment ratings obtained from 200 men during two successive cruises aboard a nuclear submarine. Patterns of psychophysiological indicators with adjustment criter...

Late cardiac morbidity and mortality among left breast cancer survivors treated with radiation therapy is related to cardiac volume included in the radiation portals. To determine if respiratory maneuvers can help decrease cardiac volume included in the radiation portals for left-sided breast cancer, 17 women with breast cancer, who had undergone left breast radiation therapy, underwent cardiac...

Two studies were conducted to quantify biological and behavioral effects resulting from exposure to controlled doses of marijuana smoke. In one study, puff volume (30, 60 and 90 ml) and in a second study, breathhold duration (0, 10 and 20 sec) were systematically varied while holding constant other smoking topography parameters (number of puffs = 10, interpuff interval = 60 sec and inhalation v...

Air-breathing marine vertebrates that dive to find food deal with two fundamental problems, the effects of pressure at depth, and the need to actively forage while breathholding. Adaptations to diving can be divided into two categories, those that are associated with adaptations to pressure, and those associated with breath-hold diving. Adaptations to pressure have to deal with the mechanical e...

Background/introduction Magnetic resonance-guided High Intensity Focused Ultrasound (MR-HIFU) ablation in the liver is complicated by the continuous motion of the target due to the respiratory cycle. Several motion compensation strategies have been proposed in the past, such as breathholding, respiratory gating and dynamic beam steering. Respiratory gating for sonication and MR thermometry uses...

Purpose: MRI is very sensitive to motion, particularly in 3D imaging where temporally localized motion can propagate across the whole reconstructed volume. In cardiac and abdominal imaging applications, subjects are required to suspend their respiration for a period of 15-25s to minimize ghosting and blurring artifacts. Breathholding poses difficulties in pediatric and elderly subjects and in p...

Near-infrared spectroscopy (NIRS) is a noninvasive system for the real-time monitoring of the concentration of oxygenated (O2Hb) and reduced (HHb) hemoglobin in the brain cortex. O2Hb and HHb concentrations vary in response to cerebral autoregulation. Sixty-eight women (14 migraineurs without aura, 49 migraineurs with aura, and 5 controls) performed breathholding and hyperventilation during NIR...