No abstract

Impaired arterial oxygenation, ranging from increased alImpaired arterial oxygenation, ranging from increased alveolar-arterial oxygen gradient (AaDo 2 ) to hypoxemia, is veolar-arterial oxygen gradient (AaDo 2 ) to hypoxemia, is comcommonly reported in patients with cirrhosis. 1 In the absence monly present in patients with cirrhosis. Nitric oxide (NO), of overt mechanical dysfunction of the lung, it has been through pulmonary vasodilatation, may play a major role in suggested that oxygenation abnormalities of cirrhotic pathe oxygen abnormalities of cirrhosis. Our aim was to study tients may be a consequence of ventilation/perfusion misthe relationship between NO production and O 2 abnormalities match and intrapulmonary shunting. 2-4 Intrapulmonary vasin 45 nonsmoking patients with cirrhosis and without major cular dilatations and artero-venous communications are cardiovascular and respiratory diseases. Intrapulmonary thought to be the pathological bases of the physiological shunting was detected by contrast-enhanced (CE) echocardimechanisms of oxygenation abnormalities. 5,6 ography. Lung volumes and diffusion, arterial blood gas analy-The vascular dilatations can result in severe hypoxemia, sis, serum NO 0 2 /NO 0 3 , NO output in the exhaled air, and which, at variance from that caused by intrapulmonary cardiac index by the echocardiographic method were detershunts, may respond normally to supplemental oxygen. mined in all patients. Twenty-seven (60%) patients had anIncreased circulation of a pulmonary vasodilator seems abnormally increased (ú15 mm Hg) AaDo 2 . The mean values to be the favored mechanism for intrapulmonary vascular of exhaled NO output and serum NO 0 2 /NO 0 3 were significantly dilatations in cirrhosis, and nitric oxide (NO) has recently higher in cirrhotic patients than in controls (252 { 117 vs.ascended to the top of the list of possible substances. 6,7 75.2 { 19 nL/min/m 2 , P õ .0001; and 47.5 { 29.4 vs. 32.9NO is a powerful local vasodilator of endothelial origin, { 10.1 mmol/L, P õ .02, respectively). In all patients, there which contributes to the normally low pulmonary vascular was a significant correlation between exhaled NO and AaDo 2 tone. 8 NO has been shown to play an important role in regulat-(r Å .78, P õ .0001). Twelve patients (26.6%) were found to ing the vasomotor tone in experimental cirrhosis. 9,10 It is now have CE-echocardiographic evidence of intrapulmonary possible to measure NO produced in the lung by measuring its shunting (positive CE-echo). Nine patients were considered concentration in exhaled air. 11,12 Recently, increased NO output to have hepatopulmonary syndrome (HPS) on the basis of an in exhaled air has been reported in patients with advanced AaDo 2 ú 15 mm Hg and positive CE-echo. These 9 patients cirrhosis, in whom exhaled NO was associated with systemic had a mean value of exhaled NO significantly higher than circulatory disturbances. 13 Exhaled NO was reported to be patients without HPS (331 { 73.2 vs. 223 { 118.4 nL/min/ raised almost threefold in t...

Impaired arterial oxygenation, ranging from increased alImpaired arterial oxygenation, ranging from increased alveolar-arterial oxygen gradient (AaDo 2 ) to hypoxemia, is veolar-arterial oxygen gradient (AaDo 2 ) to hypoxemia, is comcommonly reported in patients with cirrhosis. 1 In the absence monly present in patients with cirrhosis. Nitric oxide (NO), of overt mechanical dysfunction of the lung, it has been through pulmonary vasodilatation, may play a major role in suggested that oxygenation abnormalities of cirrhotic pathe oxygen abnormalities of cirrhosis. Our aim was to study tients may be a consequence of ventilation/perfusion misthe relationship between NO production and O 2 abnormalities match and intrapulmonary shunting. 2-4 Intrapulmonary vasin 45 nonsmoking patients with cirrhosis and without major cular dilatations and artero-venous communications are cardiovascular and respiratory diseases. Intrapulmonary thought to be the pathological bases of the physiological shunting was detected by contrast-enhanced (CE) echocardimechanisms of oxygenation abnormalities. 5,6 ography. Lung volumes and diffusion, arterial blood gas analy-The vascular dilatations can result in severe hypoxemia, sis, serum NO 0 2 /NO 0 3 , NO output in the exhaled air, and which, at variance from that caused by intrapulmonary cardiac index by the echocardiographic method were detershunts, may respond normally to supplemental oxygen. mined in all patients. Twenty-seven (60%) patients had anIncreased circulation of a pulmonary vasodilator seems abnormally increased (ú15 mm Hg) AaDo 2 . The mean values to be the favored mechanism for intrapulmonary vascular of exhaled NO output and serum NO 0 2 /NO 0 3 were significantly dilatations in cirrhosis, and nitric oxide (NO) has recently higher in cirrhotic patients than in controls (252 { 117 vs.ascended to the top of the list of possible substances. 6,7 75.2 { 19 nL/min/m 2 , P õ .0001; and 47.5 { 29.4 vs. 32.9NO is a powerful local vasodilator of endothelial origin, { 10.1 mmol/L, P õ .02, respectively). In all patients, there which contributes to the normally low pulmonary vascular was a significant correlation between exhaled NO and AaDo 2 tone. 8 NO has been shown to play an important role in regulat-(r Å .78, P õ .0001). Twelve patients (26.6%) were found to ing the vasomotor tone in experimental cirrhosis. 9,10 It is now have CE-echocardiographic evidence of intrapulmonary possible to measure NO produced in the lung by measuring its shunting (positive CE-echo). Nine patients were considered concentration in exhaled air. 11,12 Recently, increased NO output to have hepatopulmonary syndrome (HPS) on the basis of an in exhaled air has been reported in patients with advanced AaDo 2 ú 15 mm Hg and positive CE-echo. These 9 patients cirrhosis, in whom exhaled NO was associated with systemic had a mean value of exhaled NO significantly higher than circulatory disturbances. 13 Exhaled NO was reported to be patients without HPS (331 { 73.2 vs. 223 { 118.4 nL/min/ raised almost threefold in t...

No abstract

Functional abnormalities of the extrathoracic airway (EA) may produce symptoms mimicking bronchial asthma. We assessed the bronchial (B) and EA responsiveness to inhaled histamine in 40 patients with asthmatic symptoms and in nine asymptomatic controls. FEV1 and maximal mid-inspiratory flow (MIF50) were used as index of bronchial and EA narrowing. Hyperresponsiveness of the intra-(BHR) or extra-(EA-HR) thoracic airway was diagnosed when the provocative concentrations of histamine (PC20FEV1 or PC25MIF50) were less than 8 mg/ml. Fiberoptic laryngoscopy was performed in nine patients and three controls. The glottal region was measured at mid-volume of maximal inspiration (AgMI) and expiration (AgME) before and after histamine. Predominant EA-HR was found in 13 patients, predominant BHR in 12, equivalent BHR and EA-HR in another 12; no significant airway narrowing was observed in three patients and in the nine controls. EA-HR was significantly associated with female sex, sinusitis, post-nasal drip, dysphonia; BHR with atopy, wheezing and lower MEF50. The percent change in AgMI after histamine was closely related to the PC25MIF50 (r = 0.87, P less than 0.001), that of AgME to the PC20FEV1 (r = 0.78, P less than 0.01). These findings suggest that the assessment of EA responsiveness may be useful in the evaluation of asthmatic symptoms, especially in patients with no BHR.