Category Archives: Airway Narrowing

Acute Effect of Sodium Cromoglycate on Airway Narrowing Induced by 4.5 Percent Saline Aerosol: Comment

These large increases in PD20 are also unlikely to be accounted for by a placebo effect. We have studied the effects of placebo aerosol on the response to 4.5 percent saline aerosol in 11 subjects on two occasions. The pH of the placebo was 9.0 in one study and 5.5 in the other. We found that for those receiving the placebo with a pH of … Continue reading

Acute Effect of Sodium Cromoglycate on Airway Narrowing Induced by 4.5 Percent Saline Aerosol: Treatment

Although the pharmacologic challenges with methacholine and histamine have been used to assess treatment of asthma with steroids, they cannot be used to assess the effects of sodium cromoglycate. While it is common to use exercise to assess the benefits of sodium cromoglycate, challenge with hyperosmolar saline aerosol is superior to exercise testing in that a dose-response curve can be obtained, and it requires little … Continue reading

Acute Effect of Sodium Cromoglycate on Airway Narrowing Induced by 4.5 Percent Saline Aerosol: Conclusion

Sensitivity to 4.5 percent saline aerosol has been shown to relate to mast cell number and corticosteroids reduce mast cell numbers, so it is not surprising that corticosteroids reduce sensitivity to 4.5 percent saline aerosol. What is more surprising is that only 1 of 11 patients had a PD20 greater after 24 to 56 days of treatment with budesonide than they did after a single … Continue reading

Acute Effect of Sodium Cromoglycate on Airway Narrowing Induced by 4.5 Percent Saline Aerosol: Discussion

The results of this study confirm that the acute administration of sodium cromoglycate is very effective in preventing airway narrowing induced by a hyperosmolar stimulus. The results show, for the first time, that sodium cromoglycate provides additional protection when given during treatment with aerosol steroids. Further, the reduction in bronchial responsiveness to hyperosmolarity occurred in some patients independently of any improvement in resting lung function … Continue reading

Acute Effect of Sodium Cromoglycate on Airway Narrowing Induced by 4.5 Percent Saline Aerosol: Results

The geometric mean values for the PD20 and DRS are given in Table 2, together with the values for FEVj immediately measured before challenge on each study day. Individual data are shown in Figures 1 and 2. The acute administration of a single dose of sodium cromoglycate significantly reduced the sensitivity and reactivity to 4.5 percent saline aerosol in this group of patients with asthma. … Continue reading

Acute Effect of Sodium Cromoglycate on Airway Narrowing Induced by 4.5 Percent Saline Aerosol: Percent Saline Aerosol Challenge

The protocol used for this challenge is that described in detail by Smith and Anderson with some modifications. In brief, it was as follows. The saline aerosol was generated by a large volume ultrasonic nebulizer (Mist02gen 143A, Timeter Somerset, Penn) and patients inhaled the aerosol at their resting ventilation rate through a large two-way valve (Hans Rudolph No. 2700, Kansas City, MO). The airway response … Continue reading

Acute Effect of Sodium Cromoglycate on Airway Narrowing Induced by 4.5 Percent Saline Aerosol: Methods

Patients Eleven patients with asthma (ten atopic), whose characteristics, lung function, and response to 4.5 percent saline aerosol are given in Table 1, attended the laboratory on five occasions. Eight of the 11 patients had never taken corticosteroid inhalants and three had not taken steroids within the last 2, 4, and 12 months. These patients were selected for study on the basis that they were … Continue reading

Acute Effect of Sodium Cromoglycate on Airway Narrowing Induced by 4.5 Percent Saline Aerosol

Bronchial provocation testing is most commonly used for assessing the severity of bronchial responsiveness and its modulation by drugs.’ Traditionally, the pharmacologic agents histamine and methacholine have been used for bronchial provocation testing. These agents act directly on specific receptors causing bronchial smooth muscle to contract. Bronchial provocation using indirect stimuli such as exercise, cold air, hyperosmolar saline, distilled water, and sulphur dioxide have been … Continue reading