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Purpose: Nicotine is the primary constituent of cigarette smoke responsible for dependence but other components may play a role. Carbon monoxide (CO) is one candidate since it is synthesized endogenously with multiple physiological effects. This investigation was conducted to determine whether CO alters cravings associated with cigarette smoke withdrawal. Methods: With ethics approval and consent, 131 smokers were assigned to receive: (1) inhaled CO ++ Nicotine nasal spray (2) Air ++ Nicotine nasal spray (3) CO ++ Placebo nasal spray or (4) Air ++ Placebo nasal spray. Two craving scales (adapted from Hughes and Hatsukami [Hughes, J.R., & Hatsukami, D. (1986). Signs and symptoms of tobacco withdrawal. Archives of General Psychiatry, 43, 289-294] and Shiffman-Jarvik [Shiffman, S.M., & Jarvik, M.E. (1976). Smoking withdrawal symptoms in two weeks of abstinence. Psychopharmacology, 50, 35-39] referred to as HH and SJ, respectively) and a mood state questionnaire were used to assess withdrawal relief. Results: Craving scores were reduced pre- to post-treatment to some extent in all groups. On the last test day, HH revealed time by treatment differences between CO ++ Nicotine and either CO Only ( p == 0.03) or Nicotine Only ( p == 0.02). SJ revealed overall differences in pre- to post-treatment cravings ( p == 0.03) with marginal time by treatment differences between craving scores in the Placebo group versus the Nicotine Only and the Nicotine ++ CO groups ( p == 0.06 and 0.07, respectively). Treatment subjects were almost twice as likely to inhale the maximal gas (odds ratios == 1.6-2.0) compared to Placebo, suggesting that all treatments (including CO Only) were discriminated from Placebo. Conclusions: Our investigation suggests that CO exerts pharmacological effects, which may modulate craving processes associated with cigarette withdrawal, and exploration for the role of CO and other cigarette smoke constituents is warranted. [ABSTRACT FROM AUTHOR]

Objectives: Current criteria use FEV[sub 1] to assess bronchodilator responsiveness, despite its insensitivity and inability to predict improvement in symptoms or exercise tolerance. Response in lung volumes remains largely unexplored even though volume parameters, such as inspiratory capacity (IC), closely correlate with functional improvements. Therefore, we assessed the response of lung volumes (ie, by IC, total lung capacity [TLC], functional residual capacity [FRC], residual volume [RV], and FVC) to salbutamol and the relationship of these changes to improvements in the spirometry in these patients. Design: A retrospective review of data extracted from a large database of patients who were undergoing spirometry and static lung volume measurements before and after the administration of 200 µg salbutamol. Patients: Patients with an FEV[sub 1]/FVC ratio of < 85% of predicted values were defined as being severely hyperinflated (SH) if TLC was > 133% of predicted and as being moderately hyperinflated (MH) if TLC was 115 to 133% of predicted. Results: Two hundred eighty-one SH patients and 676 MH patients were identified. Salbutamol significantly reduced the mean (± SEM) TLC (SH patients, 222 ± 23 mL; MH patients, 150 ± 10 mL; p < 0.001), FRC (SH patients, 442 ± 26 mL; MH patients, 260 ± 39 mL; p < 0.001), and RV (SH patients, 510 ± 28 mL; MH patients, 300 ± 14 mL; p < 0.001) and increased both the 1C (SH patients, 220 ± 15 mL; MH patients, 110 ± 11 mL; p < 0.001) and FVC (SH patients, 336 ± 21 mL; MH patients, 204 ± 13 mL; p < 0.001). FEV[sub 1] improved in a minority of patients (SH patients, 33%; MH patients, 26%), but if lung volume measurements are also considered, the overall bronchodilator response may improve to up to 76% of the SH group and up to 62% of the MH group. Changes in volumes correlated poorly with changes in maximal airflows. Conclusions: Bronchodilators reduce... [ABSTRACT FROM AUTHOR]

Presents a letter to the editor of the journal 'Chest,' commenting on the paper 'Response of lung volumes to inhaled salbutamol in a large population of patients with severe hyperinflation,' by M.F. Newton and colleagues. Criteria for bronchodilator response in FVC; Use of functional criteria to exclude asthmatic patients from the analysis; Explanation for postbronchodilator lung volume increase.

Background: The lung function of patients with idiopathic pulmonary fibrosis (IPF) has not been characterized in detail. objective: To characterize the heterogeneous physiological abnormalities that exist in patients with IPF during their initial clinical evaluation., Methods: Lung function tests from 93 patients, performed within six months of the initial diagnosis of IPF, were obtained from a referral pulmonary function laboratory at a tertiary care hospital in Canada. A restrictive pattern was defined as total lung capacity (TLC) <95th percentile of predicted value. Patients with obstructive lung disease, lung cancer, emphysema and other restrictive lung diseases were excluded., Results: On diagnosis, 73% of patients with IPF had a restrictive pattern, with a mean TLC of 72% of predicted. Mean forced vital capacity (FVC) was 71% and 44% of patients had an FVC <95th percentile. Mean diffusing capacity for carbon monoxide (DLCO) was 60% and DLCO⁄alveolar volume (VA) 92% of predicted. Increased severity of restriction - based on TLC - was associated with lower DLCO (74% of predicted in mild restriction and 39% of predicted in severe restriction) and higher forced expiratory volume in 1 s (FEV1)⁄FVC ratio (82% of predicted in mild restriction and 90% of predicted in severe restriction) but not with age (76 years in mild restriction and 69 years in severe restriction). Regardless of severity of restriction, the average DLCO⁄VA (≥86% of predicted) remained within normal limits., Conclusions: One in four patients with IPF had normal TLC and more than one-half had a normal FVC during initial evaluation. As the severity of the restriction increased, FEV1⁄FVC increased, DLCO decreased but DLCO⁄VA remained normal.