Metabolic surgery and obstructive sleep apnoea: the protective effects of bariatric procedures.

The global epidemic of obesity and the worldwide prevalence of obstructive sleep apnoea (OSA) are both increasing. Epidemiological studies reveal an association between obesity, weight gain and OSA. Metabolic or bariatric operations provide sustained weight loss and resolve or improve the symptoms of OSA in the majority of morbidly obese individuals.

Cannabinoid effects on ventilation and breathlessness: a pilot study of efficacy and safety.

Based on the neurophysiology of dyspnoea and the distribution of cannabinoid receptors within the central nervous system, we hypothesize that the unpleasantness of breathlessness will be ameliorated in humans by cannabinoids, without respiratory depression. Five normal and four chronic obstructive pulmonary disease (COPD) subjects entered a double blind, randomized, placebo-controlled crossover study with two test days. Subjects received sublingual cannabis extract or placebo.

Developing a pictorial Epworth Sleepiness Scale.

Objective: The Epworth Sleepiness Scale (ESS) was designed to be self-completed by the patient. However, it may not be understood by all, and unrecognised problems with literacy can impair the process. The ESS has been translated into a pictorial version for use in those with normal or diminished literacy skills.

The airline passenger: current medical issues.

It is widely accepted that travel by air is unlikely to be a hazard to the vast majority of passengers. However, there are potentially adverse effects of cabin air of poor quality and of the reduced oxygen tension of the cabin environment. There is also the possibility of thrombosis related, at least in part, to the relative inactivity of a long journey.

Changes in brain morphology associated with obstructive sleep apnea.

Objective: Obstructive sleep apnea (OSA) causes hypoxemia and fragmented sleep, which lead to neurocognitive deficits. We hypothesised that focal loss of cortical gray matter generally within areas associated with memory processing and learning and specifically within the hippocampus would occur in OSA.

Methods: Voxel-based morphometry, an automated processing technique for magnetic resonance images, was used to characterise structural changes in gray matter in seven right handed, male patients with newly diagnosed OSA and seven non-apneic, male controls matched for handedness and age.

Detection of lung cancer with volatile markers in the breath.

Study Objectives: To evaluate volatile organic compounds (VOCs) in the breath as tumor markers in lung cancer. Alkanes and monomethylated alkanes are oxidative stress products that are excreted in the breath, the catabolism of which may be accelerated by polymorphic cytochrome p450-mixed oxidase enzymes that are induced in patients with lung cancer.

Design: Combined case-control and cross-sectional study.

Image features of true positive and false negative cancers in screening mammograms.

The location, tissue background and imaging characteristics of true positive and false negative screens of breast cancers have been studied. This data can aid decisions in optimizing the display of mammographic information with the objective of minimizing false negative screens. Screening mammograms for four groups of women were digitized; those with screen detected cancers, those with false negative interval cancers, and matched normals for both groups.

External high frequency oscillation in normal subjects and in patients with acute respiratory failure.

External high frequency oscillation was performed on 20 healthy volunteers using a cuirass-based system, the Hayek Oscillator. Five-min periods of oscillation were carried out on each subject at frequencies of 1, 2, 3, 4 and 5 Hz. Effective ventilation was measured in terms of the fall in alveolar partial pressure of carbon dioxide immediately after oscillation.

Camelford water poisoning accident: serial neuropsychological assessments and further observations on bone aluminium.

The serial cognitive assessment of ten individuals made between 8 and 26 months after the water at Camelford in Cornwall was accidentally contaminated with aluminium sulphate, showed consistent evidence of impairment of information processing and memory. There was no obvious relationship between these impairments and measurements of anxiety and depression. Serial bone biopsies in two individuals showed that the aluminium which was present 6 and 7 months after the accident had disappeared by 19 months.

Estimates of mean alveolar PCO2 during steady-state exercise in man: a theoretical study.

The partial pressure of carbon dioxide in arterial blood is an important operator in the control of breathing, by actions on peripheral and central chemoreceptors. In experiments on man we must often assume that lung alveolar PCO2 equals arterial PCO2 and obtain estimates of the former derived from measurements in expired gas sampled at the mouth. This paper explores the potential errors of such estimates, which are magnified during exercise.

Ventilatory responsiveness to carbon dioxide below the normal control point in conscious normoxic humans.

A recently developed CO2 pulse technique was used to test for ventilatory sensitivity to CO2 in four normal men following 2 min voluntary hyperventilation down to an end-tidal CO2 tension (PETCO2) of 20 mmHg (2.7 kPa). Pure CO2 was injected into the inspiratory limb of a breathing circuit at 0.

Hypoxia following voluntary hyperventilation during exercise in man.

The importance of carbon dioxide in the control of ventilation during exercise was tested by emptying CO2 stores by voluntary hyperventilation. Healthy subjects were studied after 3 min hyperventilation down to an end-tidal PCO2 of about 20 mmHg on a background of steady exercise at 75 W. Control runs were performed when the hyperventilation was made isocapnic by the addition of CO2.

Suction drainage: a new approach to the treatment of empyema.

Thirteen patients with empyema thoracis were treated with a new suction drainage technique. The method entails passing a catheter into the empyema cavity under ultrasound guidance and using strong suction to drain loculated pus. Eight patients had no recurrence after a single treatment and one patient had no recurrence after two treatments.

Digital gangrene in small cell lung cancer: response to aspirin treatment.

A patient who had small cell lung cancer complicated by symmetrical peripheral gangrene, secondary to spontaneous platelet aggregation, improved dramatically after starting aspirin treatment.

Local anaesthesia for fibreoptic bronchoscopy: transcricoid injection or the "spray as you go" technique?

Local anaesthesia for fibreoptic bronchoscopy should be given by a safe technique that is not unpleasant to the patient and should provide acceptable conditions for the bronchoscopist. Single injection transcricoid local anaesthesia was compared with the "spray as you go" technique in patients having day case fibreoptic bronchoscopy. Patients were randomised to receive either 100 mg lignocaine by a single cricothyroid puncture or 240 mg lignocaine instilled through the bronchoscope under direct vision.

The effect of almitrine on the steady-state ventilatory response to carbon dioxide at rest and during exercise in man.

Almitrine has potential as a tool for testing the physiological role of the peripheral chemoreceptor. The effects of almitrine on CO2 chemosensitivity were studied at rest and during light exercise using a constant inflow technique that avoids the hyperoxia of rebreathing methods. The steady-state ventilatory response to CO2 was measured in two groups of six normal men before and 150 min after 100 mg oral almitrine bismesylate or placebo.

Sedation for fibreoptic bronchoscopy: comparison of alfentanil with papaveretum and diazepam.

Sedation for fibreoptic bronchoscopy should produce optimal conditions for the operator, patient comfort and rapid recovery allowing early discharge home. We have compared a regimen producing 'light' sedation with a more traditional regimen producing 'deep' sedation. Seventy-six patients undergoing fibreoptic bronchoscopy under topical anaesthesia were randomized to receive either light sedation with the short acting opiate, alfentanil (median dose 1.