Is post-sternotomy percutaneous dilatational tracheostomy a predictor for sternal wound infections?

OBJECTIVE

Early post-sternotomy tracheostomy is not infrequently considered in this era of percutaneous tracheostomy. There is, however, some controversy about its association with sternal wound infections.

METHODS

Consecutive patients who had percutaneous tracheostomy following median sternotomy for cardiac operation at our institution from March 1998 through January 2007 were studied, and compared to contemporaneous patients. We identified risk factors for tracheostomy, and investigated the association between percutaneous tracheostomy and deep sternal wound infection (mediastinitis) by multivariate analysis.

RESULTS

Of 7002 patients, 100 (1.4%) had percutaneous tracheostomy. The procedure-specific rates were: 8.6% for aortic surgery, 2.7% for mitral valve repair/replacement (MVR), 1.1% for aortic valve replacement (AVR), and 0.9% for coronary artery bypass grafting (CABG). Tracheostomy patients differed vastly from other patients on account of older age, severe symptoms, preoperative support, lower ejection fraction, more comorbidities, more non-elective and complex operations and higher EuroScore. Risk factors for tracheostomy were New York Heart Association class III/IV (OR 6.01, 95% CI 2.28-16.23, p<0.0001), chronic obstructive pulmonary disease (OR 1.84, 95% CI 1.01-3.37, p=0.05), preoperative renal failure (OR 3.57, 95% CI 1.41-9.01, p=0.007), prior stroke (OR 3.08, 95% CI 1.75-5.42, p<0.0001), ejection fraction<0.30% (OR 2.73, 95% CI 1.23-6.07, p=0.01), and bypass time (OR 1.008, 95% CI 1.004-1.012, p<0.0001). The incidences of deep (9% vs 0.7%, p<0.0001) and superficial sternal infections (31% vs 6.5%, p<0.0001) were significantly higher among tracheostomy patients. Multivariate analysis identified percutaneous tracheostomy as a predictor for deep sternal wound infection (OR 3.22, 95% CI 1.14-9.31, p<0.0001).

CONCLUSIONS

Tracheostomy, often performed in high-risk patients, may further complicate recovery with sternal wound infections, including mediastinitis, therefore, patients and timing should be carefully selected for post-sternotomy tracheostomy.