Objective: To identify the variables that influence blood loss in endoscopic sinus surgery performed under uniform conditions of preoperative topical vasoconstriction and surgical technique.
Study design: Blind, nonrandomized, observational study.
Setting: One hundred thirty-eight consecutive patients who underwent endoscopic sinus surgery with the same technique in a university hospital over a 9-month period.
Methods: Pearson product-moment correlation was used for numerical variables and nonparametric tests for categorical variables: Mann-Whitney (comparison of two independent variables) and Kruskal-Wallis (comparison of more than two independent variables).
Main outcome measures: Operative time, total blood loss, and blood loss per minute were correlated with blood loss markers: age, sex, surgeon, type and severity of illness, septoplasty, and anesthetic agents used.
Results: No correlation was found between age, sex, surgeon, and blood loss markers. Severe polyposis produced more blood loss than mild polyposis and sinusitis. Septoplasty showed an interesting inverse correlation with blood loss. Remifentanyl with fluorinated volatile agents was accompanied by less blood loss than other anesthetic agents.
Conclusion: More blood loss occurred with more severe sinonasal pathology. Blood loss may be reduced by using remifentanyl with a fluorinated volatile agent and, possibly, preoperative infiltration with epinephrine.