Ketamine combined with dexmedetomidine reduces neutrophil lymphocyte ratio (NLR) in critically ill COVID-19 patients; a pre-experimental study

Background & objective: About 20% of patients with COVID-19 admitted to the intensive care unit (ICU) need ventilatory support under sedation using dexmedetomidine and ketamine. Ketamine has an anti-inflammatory effect and is expected to suppress immune cells. A high neutrophil-lymphocyte ratio (NLR) is associated with a severe stage of the disease. We compared NLR between COVID-19 patients under sedation with dexmedetomidine alone or with dexmedetomidine combined with ketamine. Methodology: This pre-experimental study involved a control group of patients receiving dexmedetomidine (n = 10) and the intervention group receiving dexmedetomidine and ketamine (n = 10) for sedation. NLR was evaluated before and after 24 h of sedation with the study drugs. Result: The patients' NLR increased significantly at 24 h after sedation using sole dexmedetomidine from 9.01 to 15.62 (P > 0.05). The combination of dexmedetomidine and ketamine significantly reduced NLR from 11.22 to 8.61 (P = 0.026). Both groups experienced a decrease in neutrophil count (P > 0.05). The lymphocyte count increased significantly in the intervention group (P = 0.025) and decreased in the control group. Conclusion: There is a significant NLR difference between a patient receiving dexmedetomidine sedation compared dexmedetomidine combined with ketamine. A combination of dexmedetomidine and ketamine reduces NLR compared to sole dexmedetomidine in critically ill COVID-19 patients.