Mebel, D., Akagami, R., & Flexman, A.M. (2016). Use of tranexamic acid is associated with reduced blood product transfusion in complex skull base neurosurgical procedures: A retrospective cohort study. Anesthesia and Analgesia, 122, 503–508. 

To determine the effect of tranexamic acid (TA) upon transfusion frequency and to explore the safety of TA in patients undergoing complex skull base neurosurgical procedures

The authors retrospectively examined records of patients undergoing complex skull base neurosurgical procedures. Patients were placed into one of two cohorts based upon administration of TA or not to determine the effect of TA on transfusion rates and TA-associated complications. Data were collected from patients undergoing the surgical procedure from 2001 to 2013.

• N = 503   
• MEAN AGE = TA: 49 years (SD = 13), no TA: 48 years (SD = 13)
• MALES: 40%, FEMALES: 60%
• CURRENT TREATMENT: Other
• KEY DISEASE CHARACTERISTICS: Complex skull base neurosurgery (55% acoustic neuroma and 25% meningioma) 
• OTHER KEY SAMPLE CHARACTERISTICS: TA not given until 2006

• SITE: Single site   
• SETTING TYPE: Inpatient    
• LOCATION: British Columbia, Canada

PHASE OF CARE: Active antitumor treatment

Retrospective, observational cohort study

Multivariate regression was used to identify predictors of transfusion.

The administration of TA was associated with a decreased incidence of transfusions (95% confidence interval [CI] [0.15, 0.65], p = 0.002). No evidence of an adverse event profile (95% CI) existed for either thrombotic events (adjusted odds ratio (OR) = –0.09, 95% CI [–3.5, 1.8]) or seizure activity (OR = 1.1, 95% CI [–1.7, 3.9]) associated with TA.

In patients undergoing complex skull base neurosurgical procedures, this retrospective observational study compared transfusion frequency and TA-related adverse events between two cohorts based upon the administration of TA. A significantly decreased frequency of transfusions was associated with the administration of TA; no significant increase in TA-related adverse events was reported between the two cohorts.

• Baseline sample/group differences of import
• Risk of bias (no random assignment)
• Risk of bias (sample characteristics)
• Unintended interventions or applicable interventions not described that would influence results
• Key sample group differences that could influence results
• The decrease in transfusions during the course of the study could be related to historical confounding. In addition, TA was not offered until 2006, so the cohorts were not equal. Also, the decision to administer TA was not random, neither was the dose standardized. 

Neurosurgical nurses caring for patients perioperatively may anticipate less need for transfusions in patients who receive TA perioperatively. However, the retrospective nature of this study needs confirmation of findings from future randomized, controlled trials.