Respiratory medicine
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Respiratory medicine · Jul 1993
Nasal intermittent positive pressure ventilation in acute exacerbations of chronic obstructive pulmonary disease--a preliminary study.
Ten patients (two male) suffering from acute exacerbations of long-standing chronic obstructive pulmonary disease and admitted in hypoxic, hypercapnic respiratory failure were treated with Nasal Intermittent Positive Pressure Ventilation (NIPPV) plus supplemental oxygen, on a general medical ward. The median (range) pH on admission was 7.30 (7.20-7.35), the median age was 67 years (47-77) with an FEV1 (percent of predicted) of 30 (17-39). On admission the median arterial oxygen tension (PaO2) was 4.71 kPa (3.45-6.26) on air, and the carbon dioxide tension (PaCO2) was 7.68 kPa (6.85-9.83). ⋯ Three patients later died with progressive hypercapnia, despite an initial response; with one of these patients also receiving intubation and mechanical ventilation. A further patient also received intubation and mechanical ventilation and was eventually discharged. NIPPV plus supplemental oxygen offers a method to correct hypoxaemia on a general medical ward without worsening hypercapnia for acute on chronic, hypoxic, hypercapnic respiratory failure, and warrants further investigation.
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Respiratory medicine · Jul 1993
Randomized Controlled Trial Clinical TrialVoluntary suppression of cough induced by inhalation of capsaicin in healthy volunteers.
The aim of the present study was to investigate the voluntary suppression of cough in response to capsaicin inhalation in healthy volunteers, and to determine if the dose-response curve to capsaicin was significantly altered when volunteers were asked to suppress their cough response. The quantification of the degree of voluntary suppression of induced cough could provide a new methodology for screening antitussive agents as antitussives may act by influencing voluntary control of cough. Cough was induced by inhalation of capsaicin. ⋯ In the non-suppressed challenge 23/24 subjects coughed on inhalation of capsaicin (3.33 x 10(-4) M) with a mean number of coughs of 2.92 +/- 0.34, whereas in the suppressed challenge only 3/24 subjects coughed with a mean number of coughs of 0.29 +/- 0.18 (P < 0.001). These results demonstrate that cough induced by inhalation of capsaicin can be voluntarily suppressed. The mechanism of voluntary suppression of cough is discussed in relation to capsaicin challenge and the screening of antitussive medications.