Acute respiratory dysfunction after surgery for acute type A aortic dissection.
OBJECTIVE
Acute respiratory dysfunction (ARD) can occur after acute type A aortic dissection, but relatively little is known about ARD in such patients. This study aims to analyse the clinical impact of ARD after surgery for acute type A aortic dissection and to assess possible treatment options.


METHODS
We reviewed our institutional database to identify patients who underwent surgery for acute type A dissection between October 1994 and January 2008 (n=276). Postoperative ARD was defined as oxygenation impairment (PaO(2)/FiO(2) <150) that occurred within 72 h of surgery and was not related to other documented causes of acute respiratory failure.


RESULTS
A total of 37 patients (13%) (27 male, mean age 60.7+/-11 years) experienced ARD after surgery for acute type A dissection. Intensive care unit stay was significantly longer for patients with ARD than those without (18+/-11 days vs 7.5+/-6 days, respectively, p<0.0001). However, hospital mortality was not significantly different between groups (16% for ARD patients vs 19% for patients without ARD, p=0.6). Logistic regression analysis identified preoperative multiple malperfusion as the only risk factor for ARD (OR 3.2, 95% confidence interval (C.I.): 2.2-4.9). Peak C-reactive protein levels were significantly higher in ARD patients (17.7+/-6.7 vs 9.6+/-5.4 mg dl(-1), p=0.04). Prone positioning ventilation was performed in 15 patients (40%) with severely impaired oxygenation and resulted in an immediate increase in mean oxygenation index from 71.6+/-8.8 to 138+/-92.6 (p<0.001). There was a tendency towards a shorter total time of mechanical ventilation (355+/-188 h vs 433+/-318 h, p=0.2) and shorter ICU stay (405+/-198 h vs 505+/-265 h, p=0.2) in the prone positioning subgroup.


CONCLUSIONS
ARD is a relatively common complication of surgery for acute type A dissection and is associated with increased morbidity and resource utilisation. Patients with preoperative malperfusion are at increased risk for development of ARD. Prone positioning is a viable treatment option that significantly improves pulmonary oxygenation.
Girdauskas
Evaldas
E
Department of Cardiac Surgery, Heart Center Leipzig, Strümpellstrasse 39, 04289 Leipzig, Germany. evagird@centras.lt
Kuntze
Thomas
T
Borger
Michael Andrew
MA
Röhrich
Knut
K
Schmitt
Dierk
D
Fassl
Jens
J
Falk
Volkmar
V
Mohr
Friedrich-Wilhelm
FW
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000784:Aortic Dissection / Q000601:surgery*; D001014:Aortic Aneurysm / Q000601:surgery*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D056888:Patient Positioning / Q000379:methods; D011183:Postoperative Complications / Q000175:diagnosis / Q000628:therapy; D016684:Prone Position; D012131:Respiratory Insufficiency / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D055815:Young Adult
D010100:Oxygen