his height was 165 cm , his weight was 120 kg , and he had large palatine tonsils and severe snoring , which sometimes resulted in sleep apnea .
his medical check - up , including a chest x - ray , revealed no other problems . in consideration of his sleep apnea symptoms
intubation was difficult because of his short neck , but general anesthesia with desfurane gas was stable during surgery .
after the patient awoke from general anesthesia , we observed bloody sputum during endotracheal suction . because we thought it was the result of aspiration during surgery
his vital signs were as follows : blood pressure , 120/70 mm hg ; temperature 38.4 ; heart rate , 106 beats / min ; and respiration rate , 28 breaths / min .
his white blood cell count was 29,190/mm , hemoglobin ( hb ) 13.7 g / dl , and platelet count 467,000/mm .
the erythrocyte sedimentation rate was 10 mg / dl and the c - reactive protein level was increased to 9.2 mg / dl ; nevertheless , results of the fluorescent antinuclear antibody and antineutrophil cytoplasmic antibody ( anca ) tests were negative , and the levels of c3 , c4 , and rheumatoid factor were normal .
after continuous hemoptysis for several hours , the patient 's hb level decreased rapidly to 6.8 g / dl and his blood sao2 level decreased gradually . an immediate chest x - ray ( fig .
2 ) of the lower lobe in both lungs showed ground - glass opacity and induration with the appearance of alveolar infiltrates .
the tonsillectomy site was clear , and a bronchoscopy was performed to find causative lesions within the trachea , but none were detected ( fig .
however , a bronchoalveolar lavage ( bal ) of the right middle lobe bronchus was performed , and the bloody bal fluid was observed to become redder ( fig .
the red blood cell count in the bal fluid was elevated to 3,052/mm , and on iron staining , hemosiderin - laden macrophages containing hb were detected .
thus a definitive diagnosis of dah was made , after which the patient was treated with an antihemorrhagic agent and antibiotics . after the massive hemoptysis improved , on plain chest x - ray taken 1 week later , the ground - glass opacity and indurated lesion seen at admission disappeared completely ( fig .
the patient was followed up for approximately 1 year , but no recurrence of disease could be detected .
dah may induce acute respiratory distress syndrome , and in severe cases , it is quickly fatal .
dah can be classified broadly as an immunological or nonimmunological collagenous disease , or one that is associated with immunological causes , with vasculitis accounting for 65% of cases .
it can be induced by goodpasture 's syndrome ( unrelated to tumors ) , microvasculitis associated with anca , collagenous vascular diseases , idiopathic pulmonary hemosiderosis , coagulation disorder , and diverse drugs and toxins .
although rare , it may develop after vigorous exercise , after playing a wind instrument , or , in some cases , from barotrauma caused by anesthetic gas pressure during general anesthesia [ 1 - 5 ] .
in general , pulmonary hemorrhage can be diagnosed by hemoptysis , a decrease in hb , and the presence of new infiltrations on plain chest x - ray .
in addition , in the test for diffusing capacity of the lung for carbon monoxide , cases showing more than a 30% increase in normal values suggest dah . clinically , dyspnea and hypoxemia occur simultaneously in cases of pulmonary hemorrhage , but the initial chest x - ray may show diverse patterns ;
pulmonary hemorrhage can be diagnosed by using chest computed tomography , chest magnetic resonance imaging , and bronchoscopy ; nevertheless , cases that can not be definitively diagnosed and cases with bloody lavage that gradually becomes redder ( darker ) can be diagnosed by examination of bal fluid . in addition , diagnosis can be made by assessing macrophages containing hemosiderin from a biopsy sample taken during bronchoscopy .
nonetheless , a biopsy can not be done in many cases because of the patient 's condition ; hence , pulmonary hemorrhage should be diagnosed by observing clinical features before performing various tests .
similar to the treatment of hemorrhage in other conditions , that in dah is treated by means of conventional methods such as administration of fresh frozen plasma , fibrin , and platelets . in our patient , causes of dah , such as immune disease , renal disease , vasculitis , and collagenous disease , could not be detected .
considering the timing of the appearance of dah , and the fact that no traces of hemorrhage could be detected in the surgical area after tonsillectomy , we speculated that the dah was due to barotrauma that developed after general anesthesia .
thus , severe chronic snoring may have damaged the alveolar wall , resulting in barotrauma during general anesthesia and causing dah .
we speculate that the anesthetic gas used for general anesthesia applied physical pressure to the alveoli and injured the very thin blood - gas barrier , resulting in the development of dah .
other cases of dah have been reported that were thought to be caused by the development of barotrauma during marathon running , while playing a wind instrument strenuously , and during military training ; nonetheless , the precise cause of dah in these cases has not been elucidated . in conclusion , we report a rare case of barotrauma caused by inhaled gas , which developed in our patient during tonsillectomy under general anesthesia .
 diffuse alveolar hemorrhage ( dah ) is an acute , life - threatening event . 
 the blood - gas barrier must be very thin to allow gas exchange and is therefore subjected to high mechanical stresses when the capillary pressure rises . in general anesthesia , 
 inhaled gases cause high mechanical stresses , and thus dah occurs under certain conditions . we describe a case of inferred postoperative dah . 
 a 25-year - old man had an acute episode after undergoing a tonsillectomy for snoring . during surgery , no problems occurred and no marked bleeding was observed . 
 after removal of the endotracheal tube , however , the patient had severe cough and hemoptysis . 
 the patient was treated with an antihemorrhagic agent and antibiotics . 
 he recovered after 1 week . 
 chronic snoring likely caused the alveolar damage in this patient and intubation led to dah . 
 the patient presented with a benign course that regressed spontaneously with medical intervention . 
Case Report
Discussion