The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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In acute hypoxaemic respiratory failure (HRF), oxygenation, reduction in the work of breathing and in dyspnoea may be achieved by delivering noninvasive mechanical ventilation (NIMV). Several uncontrolled and 13 randomized controlled studies (RCS) were reviewed. Uncontrolled studies confirmed the feasibility and the possibility to improve arterial blood oxygenation with NIMV. ⋯ Ten of the 13 RCS found a reduction in the mortality rate which was 30% (19-40%) in the control group and 19% (13-26%) in the NIMV group. The mean absolute risk reduction was 15% (10-20%). In conclusion, noninvasive ventilation appears to be a useful method in avoiding endotracheal intubation and probably in reducing the morbidity of patients with hypoxaemic respiratory failure.
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Randomized Controlled Trial Clinical Trial
Dose-response effect of oxygen on hyperinflation and exercise endurance in nonhypoxaemic COPD patients.
Dynamic hyperinflation contributes to exertional breathlessness and reduced exercise tolerance in chronic obstructive pulmonary disease (COPD) patients. This study examined whether oxygen supplementation results in a dose-dependent decrease in hyperinflation associated with functional and symptomatic improvement. Ten severe COPD patients without clinically significant oxygen (O2) desaturation during exercise, and seven healthy subjects, performed five exercise tests at 75% of maximally tolerated work rate. ⋯ In healthy subjects, smaller V'E and fR decreases were observed at FI,O2=0.5, accompanied by more modestly increased endurance. Oxygen supplementation during exercise induced dose-dependent improvement in endurance and symptom perception in nonhypoxaemic chronic obstructive pulmonary disease patients, which may be partly related to decreased hyperinflation and slower breathing pattern. This effect is maximized at an inspired oxygen fraction of 0.5.
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Randomized Controlled Trial Clinical Trial
The effects of pressurization rate on breathing pattern, work of breathing, gas exchange and patient comfort in pressure support ventilation.
The aim of this study was to investigate the effects of different pressurization rates during pressure support ventilation on breathing pattern, work of breathing, gas exchange and patient comfort in patients with acute lung injury. The pressurization rate modifies the initial pressure ramp by changing the initial peak flow rate: the increase in pressurization rate is associated with a decrease in the time to reach the level of pressure support ventilation by increasing the peak flow rate. Ten intubated patients (age 64+/-17 yrs, body mass index 24+/-17 Kg x m(-2), arterial oxygen tension/inspired oxygen fraction 214+/-59) were studied in random order varying the pressurization rate at 5 and 15 cmH2O of pressure support ventilation. ⋯ The lowest and the highest pressurization rates caused the worst patient comfort (p<0.05). The gas exchange was stable throughout the study. The presented results suggest: 1) the lowest pressurization rate caused the lowest tidal volume, highest respiratory rate and highest work of breathing; 2) at the other pressurization rates no differences in breathing pattern and work of breathing were observed; and 3) the patient's comfort was worse at the lowest and highest pressurization rates.
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Thoraco-abdominal asynchrony is frequently encountered during inhalation anaesthesia in children with adenotonsillar hypertrophy causing an upper airway obstruction. The study goal was to evaluate the impact of different airway opening manoeuvres on thoraco-abdominal asynchrony as a measure of airway obstruction. Thirty anaesthetized children (aged 2-8 yrs; sevoflurane 3% in 50% oxygen/nitrous oxide) were studied prior to elective adenotonsillectomy using respiratory inductance plethysmography to record ribeage and abdominal wave forms as a basis for calculation of the phase angle. ⋯ In anaesthetized children with adenotonsillar hypertrophy, airway opening manoeuvres have distinct effects on thoraco-abdominal asynchrony. Delivery of continuous positive airway pressure and jaw thrust can be the first airway opening manoeuvres to improve breathing patterns. Chin lift without additional continuous positive airway pressure should be used with caution in these patients because it may convert partial into almost complete airway obstruction.
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The reproducibility and acceptability of airways resistance measurements using the interrupter technique (MicroRint) obtained using a mouthpiece were compared with those using a face mask. Fifty children aged 4-7 yrs performed four sets of six Rint measurements; two using a mouthpiece and two using a face mask with integral mouthpiece. Complete data were obtained from 45 (90%) children using the mouthpiece and 43 (86%) children using the mask. ⋯ Sixty-seven per cent of children preferred the face mask but this was more time-consuming (p = 0.03). Children did not produce more repeatable results using their preferred method, nor did they improve with practice. Repeatable airway resistance measurements using the interrupter technique can be obtained from young children using either a mouthpiece or a face mask, but there are significant clinical and statistical differences between the results obtained.