单侧肺水肿的原因.pdf

will generate artifact in different location,whereas a truedissection will be consistent.Reconstruction by a multi-detector row CT(helical CT)in a sagittal view will also givea more accurate assessment of aortic artifact 12,13.Cardiac gating has been shown to reduce the artifact atthe aortic root 14.However,in emergency condition,itsapplication has not yet been validated 12.Transesophagealechocardiogram(TEE)could also assist in proper diagnosis.The sensitivity and specificity of TEE have been reported tobe as high as 98%and 63%to 96%,respectively 15.Themain limitation of TEE is its strong dependence on theexperience of the investigator.Missed diagnosis of aortic dissection leads to a poten-tially lethal outcome,whereas misjudgment of artificialimages results in unnecessary thoracotomy.Familiarity withthese diagnostic pitfalls of CT facilitates correct recognitionof aortic dissection.Wen-Chu Chiang MD,MPHPei-Chieh Kao MDChan-Ping Su MDDepartment of Emergency MedicineNational Taiwan University Hospital,Yun-Lin BranchTaipei 100,TaiwanE-mai address:drchianglha.mc.ntu.edu.twJuan Hsu MDDepartment of Cardiovascular SurgeryNational Taiwan University Hospital,Yun-Lin BranchTaipei 100,Taiwandoi:10.1016/j.ajem.2006.04.011References1 Klompas M.Does this patient have an acute thoracic aortic dissection?JAMA 2002;287:2262-72.2 Khan IA,Nair CK.Clinical,diagnostic,and management perspectivesof aortic dissection.Chest 2002;122:311-28.3 Trauma radiology misread/over-read images and reviews.Availableat:http:/www.trauma.org/radiology/index.html accessed on Mar30,2006.4 Hagan PG,Nienaber CA,Isselbacher EM,et al.The InternationalRegistry of Acute Aortic Dissection(IRAD):new insights into an olddisease.JAMA 2000;283:897-903.5 Spittell PC,Spittell Jr JA,Joyce JW,et al.Clinical features anddifferential diagnosis of aortic dissection:experience with 236 cases(1980 through 1990).Mayo Clin Proc 1993;68:642-51.6 Bickerstaff LK,Pairolero PC,Hollier LH,et al.Thoracic aorticaneurysms:a population-based study.Surgery 1982;92:1103-8.7 Nienaber CA,von-Kodolitsch Y,Nicolas V,et al.The diagnosis ofthoracic dissection by noninvasive imaging procedures.N Engl J Med1993;328:1-9.8 Batra P,Bigoni B,Manning J,et al.Radiographics 2000;20:309-20.9 Duvernoy O,Coulden R,Ytterberg C.Aortic motion:a potentialpitfall in CT imaging of dissection in the ascending aorta.J ComputAssist Tomogr 1995;19:569-72.10 Qanadli SD,Hajjam M,Mesurolle B,et al.Motion artifacts of theaorta simulating aortic dissection on spiral CT.J Comput AssistTomogr 1999;23:1-6.11 Wheat MW.Acute dissection of the aorta.Cardiovasc Clin 1987;17:241-62.12 Willoteaux S,Lions C,Gaxotte V,et al.Imaging of aortic dissection byhelical computed tomography(CT).Eur Radiol 2004;14:1999-2008.13 Kapustin AJ,Litt HI.Diagnostic imaging for aortic dissection.SeminThorac Cardiovasc Surg 2005;17:214-23.14 Morgan-Hughes GJ,Owens PE,Marshall AJ,et al.Thoracic aorta atmulti-detector row CT:motion artifact with various reconstructionwindows.Radiology 2003;228:583-8.15 Keren A,Kim CB,Hu BS,et al.Accuracy of biplane and multiplanetransesophageal echocardiography in diagnosis of typical acute aorticdissection and intramural hematoma.J Am Coll Cardiol 1996;28:627-36.Other causes of unilateral pulmonary edemaTo the Editor,We read with interest the article bUnilateral pulmonaryedema related to massive mitral insufficiencyQ wherein theauthors describe the occurrence of unilateral pulmonaryedema after mitral insufficiency 1.We describe a case ofunilateral pulmonary edema related to end-stage renaldisease that improved rapidly with hemodialysis and reviewthe literature for the causes of unilateral pulmonary edema.A 34-year-old man,with a known case of end-stage renaldisease(secondary to chronic glomerulonephritis)requiringmaintenance hemodialysis,presented in the emergencydepartment with severe dyspnea.Over the previous 12 hours,he experienced progressive orthopnea and cough withmucoid expectoration.The last session of hemodialysiswas administered 24 hours ago,and the patient denied anyhistory of undue salt or water intake,hemoptysis,or fever.On examination,the patient was pale,in severe respiratorydistress,and had to sit in an upright position as a result oforthopnea.Blood pressure was 160/90 mm Hg,pulse rate110/min,respiratory rate 34/min,and oral temperature37.28C.Auscultation revealed diminished breath soundsover the lower two thirds of the left lung and crackles inthe lower one third of the right lung.Auscultation of theheart was normal.The progressive orthopnea led to theinitial diagnosis of pulmonary edema,and the patient wasshifted to the respiratory intensive care unit where he wastreated with oxygen,intravenous diuretics,and morphine.Preliminary investigations revealed a white blood cell countof 12000/lL with 70%neutrophils,hemoglobin level of9.3 g/dL,creatinine level of 8.2 mg/dL,sodium level of141 mEq/L,potassium level of 5.8 mEq/L,and creatinephosphokinase(MB isozyme)of 20 IU/L.Arterial blood gasanalysis revealed a pH of 7.2,Pao2of 62 mm Hg,Paco2of25 mm Hg,and HCO3of 10 mEq/L,at Fio2of 0.28.Theelectrocardiogram demonstrated sinus tachycardia.Chestx-ray revealed a unilateral homogenous pulmonary opacityoccupying the right lower lobe and left pleural effusion(Fig.1).Bedside echocardiography was normal with a leftventricular ejection fraction of 56%.Although the patientsCorrespondence129temperature was normal,in the presence of a unilateralpulmonary infiltrate,as pneumonia could not be ruled out,treatment with intravenous cefpirome and azithromycin wasinitiated.In view of metabolic acidosis and hyperkalemiathe patient underwent hemodialysis.After the dialysis,thepatients disease course was characterized by rapid recov-ery:within a few hours,breathing improved dramaticallyand repeated arterial blood gas analysis revealed a pH of7.32,Pao2of 72 mm Hg,Paco2of 35 mm Hg,and HCO3of 18 mEq/L,at FiO20.21.Repeat chest x-ray obtained12 hours after admission showed resolution of the pulmo-nary opacity with residual left pleural effusion(Fig.2).These findings,together with the lack of fever,suggestedthat pneumonia was not a likely diagnosis.Moreover,sputum for culture and Gram stain was negative and weterminated the antibiotic treatment.The patient was inves-tigated for the left pleural effusion.Pleural biopsy showedcaseous granulomas with acid-fast bacilli.The patient wasstarted on antituberculous therapy and discharged unevent-fully after 7 days of hospitalization with advice for regularmaintenance hemodialysis.Unilateral pulmonary edema is an uncommon,if not rare,entity that can be mistaken for other causes of unilateralalveolar and interstitial infiltrates,especially pneumonia.Ithas been described after congestive heart failure 2,prolonged rest on one side in a patient with cardiacdecompensation or receiving large amounts of fluids 3,in patients with mitral valve insufficiency 1,in cases ofrapid expansion of the lung after pleural effusions andpneumothorax 4,in the normal lung in patients withunilateral pulmonary disease such as MacLeod syndrome5 and unilateral pulmonary agenesis 6,after talcpleurodesis 7,trauma 8,epilepsy 9,upper airwayobstruction 10,pulmonary artery compression from aorticdissection 11,12,pulmonary venous obstruction frommediastinal fibrosis 13 or postlobectomy 14,unilateralmain stem intubation 15,neurogenic pulmonary edema16,nitrogen mustard 17,amiodarone-related 18 andheroin-related 19 pulmonary edema,pregnancy 20,andin cases of fluid overload 21-23.Unilateral pulmonary edema can result from myriad ofcauses.Thus,even if the pulmonary opacities are unilateral,if the clinical manifestation is compatible with pulmonaryedema and not with pneumonia,early and aggressivetreatment should be initiated for pulmonary edema.Ritesh Agarwal MD,DMAshutosh N.Aggarwal MD,DMDheeraj GuptaDepartment of Pulmonary MedicinePostgraduate Institute of Medical Education and ResearchChandigarh-160012,IndiaE-mail addresses:doi:10.1016/j.ajem.2006.05.025References1 Legriel S,Tremey B,Mentec H.Unilateral pulmonary edema relatedto massive mitral insufficiency.Am J Emerg Med 2006;24(3):372.Fig.2Chest radiograph shows complete clearing of theopacities on the right side.Fig.1Chest radiograph shows prominent right hila and densehomogenous opacity in the right lower lobe;also present are leftpleural effusion and a central venous catheter for dialysis.Correspondence1302 Nitzan O,Saliba WR,Goldstein LH,Elias MS.Unilateral pulmonaryedema:a rare presentation of congestive heart failure.Am J Med Sci2004;327(6):362-4.3 Leeming BW.Gravitational edema of the lungs observed duringassisted respiration.Chest 1973;64(6):719-22.4 Murat A,Arslan A,Balci AE.Re-expansion pulmonary edema.ActaRadiol 2004;45(4):431-3.5 Saleh M,Miles AI,Lasser RP.Unilateral pulmonary edema in Swyer-James syndrome.Chest 1974;66(5):594-7.6 Nana-Sinkam P,Bost TW,Sippel JM.Unilateral pulmonary edema ina 29-year-old man visiting high altitude.Chest 2002;122(6):2230-3.7 Scalzetti EM.Unilateral pulmonary edema after talc pleurodesis.J Thorac Imaging 2001;16(2):99-102.8 Dempster AG.Unilateral pulmonary edema complicating chestcompression and cardiac avulsion.Am J Forensic Med Pathol 1986;7(4):350-3.9 Koppel BS,Pearl M,Perla E.Epileptic seizures as a cause ofunilateral pulmonary edema.Epilepsia 1987;28(1):41-4.10 Morisaki H,Ochiai R,Takeda J,Nagano M.Unilateral pulmonaryedema following acute subglottic edema.J Clin Anesth 1990;2(1):42-4.11 McTigue C,Scurry JP,Silberstein M.Unilateral pulmonary edemaassociated with pulmonary arterial compression.Australas Radiol1988;32(3):390-3.12 Takahashi M,Ikeda U,Shimada K,Takeda H.Unilateral pulmonaryedema related to pulmonary artery compression resulting from acutedissecting aortic aneurysm.Am Heart J 1993;126(5):1225-7.13 Routsi C,Charitos C,Rontogianni D,Daniil Z,Zakynthinos E.Unilateral pulmonary edema due to pulmonary venous obstructionfrom fibrosing mediastinitis.Int J Cardiol 2006;108(3):418-21.14 Gyves-Ray KM,Spizarny DL,Gross BH.Unilateral pulmonaryedema due to postlobectomy pulmonary vein thrombosis.AJR Am JRoentgenol 1987;148(6):1079-80.15 Kramer MR,Melzer E,Sprung CL.Unilateral pulmonary edema afterintubation of the right mainstem bronchus.Crit Care Med 1989;17(5):472-4.16 Perrin C,Jullien V,Venissac N,Lonjon M,Blaive B.Unilateralneurogenic pulmonary edema.A case report.Rev Pneumol Clin 2004;60(1):43-5.17 Goodman LR,Shanser JD.Unilateral pulmonary edema.An unusualcomplication of nitrogen mustard therapy.Radiology 1976;120(1):166.18 Herndon JC,Cook AO,Ramsay MA,Swygert TH,Capehart J.Postoperative unilateral pulmonary edema:possible amiodaronepulmonary toxicity.Anesthesiology 1992;76(2):308-12.19 Sporer KA,Dorn E.Heroin-related noncardiogenic pulmonary edema:a case series.Chest 2001;120(5):1628-32.20 Choi HS,Choi H,Han S,et al.Pulmonary edema during pregnancy:unilateral presentation is not rare.Circ J 2002;66(7):623-6.21 Balogun SA,Balogun RA.Acute unilateral pulmonary edema fromdietary salt and water load:a case report and review of the literature.Conn Med 2001;65(11):653-6.22 Di Benedetto C,Brunner W,Kuhn M.Unilateral pulmonaryedema in a dialysis patient with massive fluid overload and mitralvalve insufficiency.Schweiz Rundsch Med Prax 2003;92(29-30):1265-8.23 Wong KS,Lin GJ,Lai CH,Lien R.Unilateral pulmonary edema:anuncommon presentation of poststreptococcal glomerulonephritis.Pediatr Emerg Care 2003;19(5):337-9.Correspondence131