Synergistic Activity Comparison between Colistin/Tigecycline and Colistin/High Dose Meropenem against Carbapenem Resistant Enetrobacteriaceae in Critically Ill Patients with Ventilator Associated Pneumoniae

Universally, A very difficult to-treat gram negative bacteria, including but not excluded to carbapenem-resistant enterobacteriaceae (CRE), are increasing rapidly. With the shortages of the newer anti-CRE antibiotics in our country, CRE-associated pneumonia and sepsis management are primarily restricted to colistin. Therefore in this study, we primarily tested the adjunctive clinical impacts of tigecycline (Group I) compared with high dose extended infusion meropenem (Group II) regarding hemodynamics, infectious values, and overall major clinical outcomes in mechanically ventilated critically ill patients. Methods: We perform a retrospective analysis of 114 eligible critically ill patients admitted to the adult ICU between April 2017 and April 2019. All patient's continuous variables were expressed as Mean ±SD by using the independent T-Test. Regarding categorical variables, Chi Square test was used to express them as numbers with percentages. Results: The mean overall age was 58.4±9.95 years. 53 subjects (46.49%) were female and 61 subjects (53.51%) were male. The 28-day survival was significantly higher in Group I (50 (92.6%)) than Group II (48 (80.0%)). Objectively, the hemodynamic parameters were positively and significantly higher in Group I versus Group II. Group I had a significantly higher %∆ALB and significantly lower %∆CRP:ALB compared with Group II (32.6%±15% vs 28.8%±15% and 71.9%±16% vs 286%±301%, respectively). Also, the ICU stay days and mortalities were significantly decreased in Group I compared with Group II with ICU stay days, early, late, and 28-day mortality were 7.93±0.26 days, 2 (3.7%), 2 (3.7%), and 4 (7.4%) vs 11.8±5.5 days, 2 (3.33%), 10 (16.7%), and 12 (20.0%). Conclusion: In conclusion, the present study has shown that colistin is more effective with a significant positive impacts on clinical outcomes when used in combination with standard dose of tigecycline than high dose meropenem extended infusion in CRE associated pneumonia and septic critically ill patients. In case of CRE associated infections, It is highly advisable to use tigecycline or at least high dose meropenem extended infusion strategy as a pharmacodynamic booster agents with the renal adjusted colistin.