Warning: Undefined variable $zfal in C:\Inetpub\vhosts\kidney.de\httpdocs\mlpefetch.php on line 525
Deprecated: str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated in C:\Inetpub\vhosts\kidney.de\httpdocs\mlpefetch.php on line 525
Warning: Undefined variable $sterm in C:\Inetpub\vhosts\kidney.de\httpdocs\mlpefetch.php on line 530
Warning: Undefined variable $sterm in C:\Inetpub\vhosts\kidney.de\httpdocs\mlpefetch.php on line 531
English Wikipedia
Nephropedia Template TP (
Twit Text
DeepDyve Pubget Overpricing |
lüll Acute severe asthma: pathophysiology and pathobiology of gas exchange abnormalities Rodriguez-Roisin REur Respir J 1997[Jun]; 10 (6): 1359-71Acute severe asthma, or "status asthmaticus", is a devastating clinical condition ultimately resulting in life-threatening hypoxaemia. The pivotal intrapulmonary mechanism of this condition is profound ventilation/perfusion (V'A/Q') mismatch, characterized by a predominant bimodal blood flow pattern reflecting a marked deterioration (increase) of the dispersion of pulmonary blood flow. This V'A/Q' profile is consistent with the presence of numerous alveolar units with low V'A/Q' ratios, in which ventilation is markedly reduced, although never abolished, but perfusion is maintained. Further V'A/Q' worsening whilst breathing 100% O2 suggests the presence of an underlying vigorous hypoxic vascular response. Of equal importance, gas exchange disturbances are poorly related to the severity of reduced maximal airflow rates. Inhaled platelet-activating factor (PAF), both in normal individuals and asthmatic patients, results in moderate-to-severe disturbance of V'A/Q' status, a finding that is probably related to altered microvascular permeability within the airway wall. Salbutamol, but not ipratropium bromide, prevented all PAF-induced systemic and lung function abnormalities, possibly because venoconstriction in the bronchial circulation was antagonized. Taken together, these findings support the hypothesis that platelet-activating factor may play a critical role in the pathobiology of severe acute exacerbations of asthma.|*Pulmonary Gas Exchange[MESH]|Acute Disease[MESH]|Capillary Permeability[MESH]|Humans[MESH]|Lung/blood supply/pathology[MESH]|Platelet Activating Factor/physiology[MESH]|Pulmonary Ventilation[MESH]|Status Asthmaticus/pathology/*physiopathology[MESH]|Ventilation-Perfusion Ratio[MESH] |