We appreciate the interest of Dr. Tornero-Campello in the anesthesiologist's role in the prevention of surgical site infections (SSIs). Further, we note his repeated contention that the duration of hospitalization is a more appropriate outcome measure than the incidence of infection is been published in letters to multiple journals.1–3
Our objectives in preparing this article4
were to produce an evidence-based, timely, concise, and clinically relevant document to educate practicing anesthesiologists regarding the best approaches to reducing surgical site infections. We believe that there is sufficient evidence to suggest that normobaric hyperoxia reduces the incidence of SSI in colorectal surgery.5,6
Nevertheless, Dr. Tornero-Campello's focus on hospital duration of stay as an outcome measure allows us to reexamine these data in greater detail.
Dr. Tornero-Campello notes that one study7
that included a heterogenous population of patients undergoing major abdominal surgery did not show a benefit of hyperoxia and may have been associated with an increase in morbidity and in the duration of hospitalization. It is extremely important to note that criticism of this study has been significant. For example, variables such as anesthetic technique, fluid management, and pain management were not controlled.8,9
Information on blood glucose control, strongly associated with the incidence of SSI, was not included.10
The small sample size and statistical analysis has not held up to rigorous post hoc
Although patients were prospectively randomized to their perioperative oxygen group, the presence of SSI was determined by retrospective chart review,8,9
as we note in our article. It is imperative that we consider these methodologic flaws when we weigh the results of this study. Last, it would seem intuitive that if hyperoxia did confer an increase risk of “clinically significant harm,” some hint of this risk would have been evident in the two larger studies by Grief et al. 5
and Belda et al.6
Faults with the above study aside, we concede that the use of hyperoxia was not associated with a decrease in the duration of hospitalization in either of the two studies cited in our review.5,6
Nevertheless, we reject Dr. Tornero-Campello's assertion that the prevention of SSI is only significant if it results in a tenable “difference in days of hospitalization, time to solid food intake, or staples removed.” Indeed, it is difficult for us to imagine any SSI that is not clinically significant: Even an infection that may be easily treated in the outpatient setting results in the use of antibiotics, which may further increase the prevalence of antibiotic-resistant organisms and leads to an increased cost of care.4,12
Although we may debate the clinical significance of hyperoxia in the prevention of SSIs, we hope Dr. Tornero-Campello will agree that the prevention of any infection, even if it not associated with an increase in duration of hospitalization, is a clinically relevant outcome and a substantial improvement in patient care.
William J. Mauermann, M.D.
Edward C. Nemergut, M.D.*
*University of Virginia Health System, Charlottesville, Virginia. email@example.com
1. Tornero-Campello G: Clinical use of normobaric hyperoxia (letter). Am J Respir Cell Mol Biol 2006; 35:404
2. Tornero-Campello G: Randomized clinical trial to evaluate the effects of perioperative supplemental oxygen administration on the colorectal anastomosis (Br J Surg 2006; 93: 698-706) (letter). Br J Surg 2006; 93:1148
3. Tornero-Campello G: Randomized clinical trial of multimodal optimization of surgical care in patients undergoing major colonic resection (Br J Surg 2005; 92: 1354-1362) (letter). Br J Surg 2006; 93:891
4. Mauermann WJ, Nemergut EC: The anesthesiologist's role in the prevention of surgical site infections. Anesthesiology 2006; 105:413–21
5. Greif R, Akca O, Horn EP, Kurz A, Sessler DI: Supplemental perioperative oxygen to reduce the incidence of surgical-wound infection. Outcomes Research Group. N Engl J Med 2000; 342:161–7
6. Belda FJ, Aguilera L, Garcia de la Asuncion J, Alberti J, Vicente R, Ferrandiz L, Rodriguez R, Company R, Sessler DI, Aguilar G, Botello SG, Orti R, Spanish Reduccion de la Tasa de Infeccion Quirurgica Group: Supplemental perioperative oxygen and the risk of surgical wound infection: A randomized controlled trial. JAMA 2005; 294:2035–42
7. Pryor KO, Fahey TJ III, Lie CA, Goldstein PA: Surgical site infection and the routine use of perioperative hyperoxia in a general surgical population: A randomized controlled trial. JAMA 2004; 291:79–87
8. Hopf HW, Hunt TK, Rosen N: Supplemental oxygen and risk of surgical site infection. JAMA 2004; 291:1956
9. Akca O, Sessler DI: Supplemental oxygen and risk of surgical site infection. JAMA 2004; 291:1956–7
10. O'Neill MJ Jr: Supplemental oxygen and risk of surgical site infection. JAMA 2004; 291:1958
11. Greif R, Sessler DI: Supplemental oxygen and risk of surgical site infection. JAMA 2004; 291:1957
12. Bratzler DW, Houck PM, Richards C, Steele L, Dellinger EP, Fry DE, Wright C, Ma A, Carr K, Red L: Use of antimicrobial prophylaxis for major surgery: Baseline results from the National Surgical Infection Prevention Project. Arch Surg 2005; 140:174–82
© 2007 American Society of Anesthesiologists, Inc.