Predicting Surgical Site Infection by ‘Suction Drain Tip’ and ‘Drain Fluid’ Cultures: Are they Helpful?

Abstract

Abstract: Introduction: The aim of the study was to check the predictability of ‘suction drain tip’ and ‘drain fluid’ cultures for detecting their association with possible surgical site infection. Material and Methods: This was an observational study conducted in Surgical Unit 1, Civil Hospital Karachi from February 2017 to November 2017. All post-operative patients having closed drains were included in the study excluding the patients who did not require drains in post-operative period. Cultures from drain fluid and drain tip were sent. The sensitivity, specificity, positive and negative predictive values were calculated. Result: The predictability for surgical infections in positive drain tip cultures showed Sensitivity =100% and Specificity = 61%. With Positive Predictive Value = 30.3 % and Negative Predictive Value = 100%. In drain fluid cultures the sensitivity was slightly low (85% ) with Specificity = 76.3%. Positive Predictive Value = 37.8% and Negative Predictive Value = 96.8%. Conclusion: We conclude that positive tip cultures and drain fluid can be important predictors of infection with high sensitivity but low specificity.