MODERATE BLOOD TRANSFUSION TRIGGERS AND SURGICAL SITE INFECTIONS IN
COLORECTAL SURGERY
Caitlin W. Hicks MD, MS1; Steven M. Frank MD2, Jack O. Wasey BM BCh2, Julie A. Freischlag MD1,
Martin A. Makary MD, MPH1; Elizabeth C. Wick MD1
1
Department of General Surgery, Johns Hopkins Hospital, Baltimore, MD 21287
Department of Anesthesiology & Critical Care Medicine, Johns Hopkins Hospital, Baltimore, MD 21287
2
Background: The decision to transfuse can be difficult given the potential concern for ongoing bleeding in the
context of physiologic fluid shifts following major surgical procedures. Guidelines support restrictive
hemoglobin (Hb) transfusion triggers (7-8 g/dL) following major surgical procedures based on randomized trials
demonstrating equivalent outcomes and observational studies showing decreased infections compared to higher
transfusion triggers (10 g/dL). Our aim was to evaluate the association between moderate transfusion triggers (79g/dL) and surgical site infections (SSI).
Methods: We prospectively followed all patients undergoing colorectal surgery at an academic tertiary medical
center (07/2010-11/2012). SSI and blood utilization (blood transfusions and Hb prior to transfusion) were
measured using ACS-NSQIP and institutional blood utilization databases. Multivariate regression was used to
determine impact of transfusion on SSI.
Results: 337/829 (38%) colorectal surgery patients had a nadir Hb of 7-9 g/dL during hospitalization.
Transfused patients (35.9%, 121/337) were older (61±16 vs. 52±16 years; p<0.0001) with a higher proportion of
males (47.1% vs. 34.3%; p=0.02) and higher mean ASA class [3 (IQR 3,3) vs. 3 (IQR 2,3); p<0.0001] compared
to non-transfused patients. There were no differences in race, body mass index, wound classification, smoking
history, or COPD between groups. On univariable analysis, SSI incidences were similar between transfused and
non-transfused patients (Table). The risk-adjusted odds of SSI after transfusion was 1.1 (95% CI 0.63, 1.89;
p=0.74) after accounting for standard general surgery NSQIP risk factors for SSI.
Conclusion: Use of a moderate hemoglobin transfusion trigger (7-9 g/dL) does not increase risk of SSI. Blood
transfusions can be used judiciously without increased risk of morbidity in colorectal surgery.
Table. Univariable Analysis of Surgical Site Infections (SSI) and RBC Transfusion
Infectious Outcome
RBC Transfusion
P value
Yes (n=121)
No (n=216)
% (#)
% (#)
23.1 (28)
23.6 (51)
0.92
Superficial SSI
16.5 (20)
17.1 (37)
0.89
Deep SSI
0.0 (0)
2.3 (5)
0.16
Organ space SSI
6.6 (8)
4.2 (9)
0.33
Any Surgical Site Infection