Diffusing capacity and spirometry following a 60-minute dive to 4.5 meters.

The purpose of this study was to assess the contribution of SCUBA to the pulmonary effects of diving to 4.5 meters depth in healthy subjects using a randomized crossover control condition. Ten healthy divers performed two 60-minute 'dives' using SCUBA in a swimming pool. The non-immersed 1 ATA SCUBA control exposure took place at ambient pressure in the laboratory. Thirty minutes prior to, and 30 and 90 minutes post-exposure, FVC (forced vital capacity), FEV1.0 (forced expired volume), peak expiratory flow rate (PEFR), diffusing capacity (DL(co)), heart rate (HR) and temperature were measured. No significant differences were noted in HR, temperature or spirometry between the two conditions. A significant reduction in diffusing capacity occurred at 30 and 90 minutes after the pool dive (9.3% and 15.1%, respectively, p < 0.05). There was no concordant change in DL(co) following the non-immersed 1 ATA SCUBA control. Thus, a pool dive to 4.5 meters for 60 minutes causes a decrease in DL(co), without a change in spirometry, while breathing from SCUBA equipment without immersion causes no significant change in lung function.

Effects of inhaled bronchodilators and corticosteroids on exercise induced arterial hypoxaemia in trained male athletes.

OBJECTIVES: To determine the effect of prophylactic treatment with an inhaled bronchodilator and anti-inflammatory on arterial saturation (SaO2) in trained non-asthmatic male athletes with exercise induced arterial hypoxaemia (EIAH). METHODS: Nine male athletes (mean (SD) age 26.3 (6.7) years, height 182.6 (7.9) cm, weight 79.3 (10.5) kg, VO2MAX 62.3 (6.3) ml/kg/min, SaO2MIN 92.5 (1.1)%) with no history of asthma were tested in two experimental conditions. A combination of a therapeutic dose of salbutamol and fluticasone or an inert placebo was administered in a randomised crossover design for seven days before maximal cycling exercise. Oxygen consumption (VO2), ventilation (VE), heart rate (HR), power output, and SaO2 were monitored during the exercise tests. RESULTS: There were no significant differences between the drug (D) and placebo (P) conditions for minimal SaO2 (D = 93.6 (1.4), P = 93.0 (1.1)%; p = 0.93) VO2MAX (D = 61.5 (7.2), P = 61.9 (6.3) ml/kg/min; p = 0.91), peak power (D = 444.4 (48.3), P = 449.4 (43.9) W; p = 0.90), peak VE (D = 147.8 (19.1), P = 149.2 (15.5) litres/min; p = 0.82), or peak heart rate (D = 182.3 (10.0), P = 180.8 (5.5) beats/min; p = 0.76). CONCLUSIONS: A therapeutic dose of salbutamol and fluticasone did not attenuate EIAH during maximal cycling in a group of trained male non-asthmatic athletes.

Effect of hyperbaric oxygen on oxygen uptake and measurements in the blood and tissues in a normobaric environment.

OBJECTIVE: To examine venous partial pressure of oxygen (PvO(2)), transcutaneous oxygen tension (tcPO(2)), and VO(2)MAX in a normobaric environment after a single hyperbaric oxygen (HBO(2)) treatment. METHODS: This was a prospective study of conditions after the intervention compared with baseline. The participants were 10 moderately trained (VO(2)MAX = 57.6 ml/kg/min) men. Two HBO(2) treatments consisting of breathing 95% oxygen at 2.5 atmospheres absolute (ATA) for 90 minutes were administered on non-consecutive days. Baseline testing included measures of VO(2)MAX, tcPO(2), and anthropometry. At 6.0 (1.0) minutes after the first HBO(2) treatment, a VO(2)MAX test was performed. After the second HBO(2) treatment, leg and chest tcPO(2) and PvO(2) were monitored for 60 minutes. RESULTS: VO(2)MAX, running time, and peak blood lactate were not altered after the HBO(2) treatment. Leg tcPO(2) was lower (p = 0.003) and chest tcPO(2) was unchanged after the HBO(2) treatment compared with baseline values. PvO(2) was significantly (p<0.001) lower in the first three minutes after treatment than subsequent values, but no other differences were found. CONCLUSIONS: A single HBO(2) treatment at 2.5 ATA for 90 minutes does not raise PvO(2), tcPO(2), or VO(2)MAX in a normobaric, normoxic environment.

Fetal cleft lip and palate detection by three-dimensional ultrasonography.

OBJECTIVES: To demonstrate a standardized approach for the evaluation of cleft lip and palate by three-dimensional (3D) ultrasonography. DESIGN: This was a retrospective study of seven fetuses with confirmed facial cleft anomalies. Post-natal findings were compared to a blinded review of 3D volume data from abnormal fetuses with seven other normal fetuses that were matched for gestational age. Upper lip integrity was examined by 3D multiplanar imaging. Sequential axial views were used to evaluate the maxillary tooth-bearing alveolar ridge contour and anterior tooth socket alignment. Alveolar ridge disruption suggested cleft palate. Premaxillary protrusion, either by multiplanar imaging or surface rendering, indicated bilateral cleft lip and palate. RESULTS: Post-natal findings confirmed bilateral cleft lip and palate (four cases), unilateral cleft lip and palate (one case), and unilateral cleft lip (two cases). Multiplanar review identified all three fetuses with unilateral cleft lip, three of four fetuses with bilateral cleft lip, one fetus with unilateral cleft palate, and three of four fetuses with bilateral cleft palate. Surface rendering correctly identified all cleft lips, with the exception of one fetus, who was thought to have a unilateral cleft lip and palate, despite the actual presence of a bilateral lesion. One cleft palate defect was directly visualized by 3D surface rendering. No false-positives occurred. CONCLUSION: Interactive review of standardized 3D multiplanar images allows one to evaluate labial defects, abnormalities of the maxillary tooth-bearing alveolar ridge, and presence of premaxillary protrusion for detecting cleft lip and palate anomalies. Surface rendering may increase diagnostic confidence for normal or abnormal studies. This technology provides an array of visualization tools that may improve the prenatal characterization of facial clefts, particularly of the palate.