Lung volumes of extreme breath-hold divers

Achievements in breath-hold diving depend, amongst others, on body oxygen stores at start of dive. A diver with very high lung volumes could increase dive's duration, and attain deeper depths for a given speed. Thus, we hypothesized that extreme breath-hold divers have very high lung volumes. On eight extreme breathhold divers (age 35 + 4 years, height 179 + 7 cm, body mass 76 + 6 kg) and 9 non-diving controls (age 37 + 6 years, height 177 + 4 cm, body mass 81 + 9 kg) residual volume, vital capacity and total lung capacity (TLC) were measured with a body plethysmograph. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were measured with a spirometer. Peak expiratory flow and flow-volume loops were measured with a pneumotachograph. In divers, but not in controls, volumes and capacities were systematically and significantly (p<0.01, paired t-test) higher than predicted from their body size. Consistently, volumes and capacities were significantly higher in divers than in controls, except for residual volume. Divers' TLC was 22% higher than predicted, and 21% higher than in controls. All divers' TLC was higher than 8 L, two had it higher than 9 L. FVC and FEV1 were significantly higher in divers than in controls. The FEV1/FVC ratio was the same in both groups. We conclude that extreme breath-hold divers may constitute a niche population with physiological characteristics different from those of normal individuals, facilitating the achievement of excellent diving performance

Accuracy of positive airway pressure titration through telemonitoring of auto‐adjusting positive airway pressure device connected to a pulse oximetry in patients with obstructive sleep apnea

Abstract Purpose In COVID‐19 era, all forms of access of patients to the sleep units should be reduced as much as possible when implementing telemedicine. In the field of obstructive sleep apnea (OSA) therapy with positive airway pressure (PAP) devices, telemedicine includes the use of built‐in software (BIS) and storage of PAPs and remote‐controlled data (BISrc data) that are processed and transmitted daily to sleep units. We compared two methods of evaluating the final residual severity of OSA patients in home PAP titration: BISrc data versus nocturnal portable multichannel monitoring (PM) data in PAP (reference method) and to verify whether the efficacy PAP therapy guided by BISrc data was clinically adequate. Methods We conducted a real‐life prospective study in newly diagnosed patients with OSA. Patients used an auto‐adjusting positive airway pressure (AirSense 10 ResMed) with a pulse oximeter that allows daily transfer of BISrc data (apnea hypopnea index [AHI] and SaO2) and remote changes in ventilator setting. Once the PAP titration was completed, the pressure value or ranges were kept constant for 3 days and home PM was repeated. Results There were 41 patients with moderate to severe OSA who completed the study. When considering AHI only, the diagnostic accuracy of BISrc on the third day was equal to 97.5%; when considering AHI > 10/h, ODI > 10/h, and SaO2 < 90%, the diagnostic accuracy slightly decreased to 90.2%. Conclusion In clinical practice, the two measurement methods are equivalent. The use of BISrc data for home titration would reduce the access to sleep units. We urge that widespread use of BISrc be promoted in the current practice of management of OSA

Predictors of 6-month mortality in elderly patients with mild chronic obstructive pulmonary disease discharged from a medical ward after acute nonacidotic exacerbation.

OBJECTIVES: To identify clinical outcomes and variables associated with 6-month mortality in very elderly patients admitted for nonacidotic acute exacerbation of chronic obstructive pulmonary disease (AECOPD). DESIGN: Prospective cohort study. SETTING: General medicine acute care ward. PARTICIPANTS: Two hundred forty-four elderly patients with COPD (mean age+/-standard deviation 82+/-7, 55.7\% female) admitted to the hospital because of non-acidotic AECOPD. MEASUREMENTS: Cognitive and mood status and physiological variables were measured. Self-reported comorbidities were assessed using the Charlson Comorbidity Index. In-hospital and long-term mortality and clinical outcomes were recorded. RESULTS: At admission, this elderly population with AECOPD had low cognitive performance (mean Mini-Mental State Examination score 21+/-5), no presence of significant depressive symptoms (Geriatric Depression Scale score 4+/-3), good nutritional status (body mass index (BMI) 25.1+/-5.5), moderate comorbidity (Charlson Comorbidity Index 4.0+/-1.9), high functional disability (Barthel Index (BI) 52+/-34), and moderate severity of acute exacerbation (Acute Physiology and Chronic Health Evaluation (APACHE) II score 9.7+/-4.2). Two hundred twenty-five inpatients with AECOPD were successfully discharged, whereas 15 were transferred to the intensive care unit, and four died in the hospital. The 6-month cumulative mortality rate in discharged patients with AECOPD was 20\%. Multivariate Cox analysis shows that lower BMI (beta=-0.16; 95\% confidence interval (CI)=0.73-0.99), higher APACHE II score (beta=0,17; 95\% CI=1.03-1.36), and lower BI at discharge (beta=-0.02; 95\% CI=0.96-0.99) were independently associated with 6-month mortality. CONCLUSION: Malnutrition, severity of exacerbation and disability status could be identified as risk factors associated with 6-month mortality of elderly patients admitted for nonacidotic AECOPD

Microwave-Assisted Drying for the Conservation of Honeybee Pollen

Bee pollen is becoming an important product thanks to its nutritional properties, including a high content of bioactive compounds such as essential amino acids, antioxidants, and vitamins. Fresh bee pollen has a high water content (15%–30% wt %), thus it is a good substrate for microorganisms. Traditional conservation methods include drying in a hot air chamber and/or freezing. These techniques may significantly affect the pollen organoleptic properties and its content of bioactive compounds. Here, a new conservation method, microwave drying, is introduced and investigated. The method implies irradiating the fresh pollen with microwaves under vacuum, in order to reduce the water content without reaching temperatures capable of thermally deteriorating important bioactive compounds. The method was evaluated by taking into account the nutritional properties after the treatment. The analyzed parameters were phenols, flavonoids, with special reference to rutin content, and amino acids. Results showed that microwave drying offers important advantages for the conservation of bee pollen. Irrespective of microwave power and treatment time, phenol and flavonoid content did not vary over untreated fresh pollen. Similarly, rutin content was unaffected by the microwave drying, suggesting that the microwave-assisted drying could be a powerful technology to preserve bioprotective compounds in fresh pollen