Respiration; international review of thoracic diseases
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We report 7 patients with severe acute asthma unresponsive to standard medication, including sympathomimetic agents, aminophylline and corticosteroids, who responded to inhaled frusemide. All were hypercapneic with a mean PaCO2 of 7.7 kPa (57.7 mm Hg) [range 6.2-8.8 kPa (46.2-66.3 mm Hg)]. ⋯ No adverse effect was recognized. Inhaled frusemide should be considered for treatment of acute asthma refractory to conventional therapy.
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Comparative Study Clinical Trial
Changes in arterial and transcutaneous oxygen and carbon dioxide tensions during and after voluntary hyperventilation.
The purposes of our study were (1) to investigate whether a 3-min short-term hyperventilation leads to posthyperventilatory hypoxemia and (2) to assess the role of transcutaneous blood gas measurements for monitoring oxygen and carbon dioxide changes during the after the test. In 10 male volunteers arterial and transcutaneous blood gases were measured simultaneously before, during and after a 3-min voluntary hyperventilation maneuver. Baseline arterial PO2 increased from 13.7 +/- 0.4 kPa (103 +/- 3 mm Hg) to 18.6 +/- 0.3 kPa (139 +/- 2.3 mm Hg; p < 0.005 compared to baseline) during hyperventilation. ⋯ A short-term over-breathing of 3 min causes a significant posthyperventilatory hypoxemia. We hypothesize that posthyperventilatory hypoxemia is caused by hypopnea as a result of depleted CO2 body stores. Noninvasive transcutaneous blood gas measurements are not reliable for monitoring blood gas changes during and after hyperventilation, most probably because of the slow response time of the electrodes and the reflex vasoconstriction of the skin vessels.
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Comparative Study
Lack of ventilatory threshold in patients with chronic obstructive pulmonary disease.
We investigated whether the ventilatory threshold (VET) could be detected in 25 patients with severe chronic obstructive pulmonary disease (COPD). Exercise on a treadmill was performed until symptom-limited maximum oxygen uptake (VO2SL) was obtained. VET was absent in 14 patients (56%, VET(-) group) and present in the others (44%, VET(+) group). ⋯ The changes in PaO2 and PaCO2 were not different between the two groups, but changes in pH and HCO3- in VET(+) were greater than those in VET(-). These results suggest that the absence of VET in some COPD patients indicates a lower exercise capacity without producing metabolic acidosis. This may be caused by rapidly developing dyspnea.
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Randomized Controlled Trial Comparative Study Clinical Trial
Evaluation of intercostal cryoanalgesia versus conventional analgesia in postthoracotomy pain.
The objective of the study was to evaluate the effects of cryoanalgesia in patients undergoing posterolateral thoracotomy. A double-blind randomized and prospective study was performed in 100 patients undergoing thoracotomy. They were randomized into two groups: Group A, 55 patients, who had undergone an intercostal cryoanalgesia and group B, control, 45 patients treated only with pharmacological analgesia ad libitum. ⋯ Maximal static inspiratory pressure (PImax) showed no significant changes and no significant differences were found between the two groups. Maximal static expiratory pressure (PEmax) significantly decreased (p < 0.001) in the 1st and 2nd week and it was not related to the type of analgesia used. We advocate the use of cryoanalgesia since it significantly reduces pain as well as the doses of analgesia.
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Piston driven volume-cycled home ventilators increase work of breathing in the synchronized intermittent mandatory ventilation mode. A 2-year-old trisomy 21 patient with chronic lung disease due to recurrent aspiration pneumonia required a ventilator rate of 6-8 breaths per minute awake and 15 asleep, with peak pressure of 32 cm H2O and positive end-expiratory pressure (PEEP) of 10 cm H2O. Two circuits were designed to facilitate breathing and respiratory mechanics of his spontaneous breaths on both were compared. ⋯ The continuous positive airway pressure (CPAP) system provided continuous flow with a CPAP device set to deliver a pressure 2 cmH2O higher than the PEEP valve. On the CPAP system, compared to the reservoir system, dynamic compliance was greater [1.52 (0.14 SD) ml/cm H2O/kg vs. 0.39 (0.02), p < 0.001] and resistance less [8.15 (1.26) cm H2O/l/s vs. 45.86 (0.87), p < 0.001] as measured with a PeDS machine. This is an innovative use of a CPAP device.