Comparison of C-Reactive Protein Levels, Neutrophil Count, and Clinical Outcomes between Low-Dose Ketamine Given at the End of Surgery and at Induction in Laparotomy

Background: Both surgery and anesthesia can cause an inflammatory response, rise in C-reactive protein (CRP) levels in response to the acute phase, as well as the activation and increased number of neutrophils. Ketamine with the right time of administration is expected to control the inflammatory response so that it can reduce the risk of postoperative complications such as pain and reduce the use of opioids. Patients and Methods: A total of 68 patients with physical status American Society of Anesthesiologists (ASA) I–II who underwent elective laparotomy were collected by consecutive sampling. The samples were divided into 2 groups; Group A received a low dose of ketamine at the end of the surgery, and Group B received a low dose of ketamine at the time of anesthesia induction. We measured CRP level, neutrophil count, visual analog scale (VAS), as well as total morphine consumption at 24 h postoperatively. Results: The increase in CRP levels in Group A was significantly lower compared to Group B (70.8 ± 42.7 vs. 115.0 ± 44.0 mg/L, P = 0.001). Group A has a significantly lower increase in CRP levels, VAS, and the total consumption of morphine 24 h postoperatively ( P < 0.05). There was a strong positive between CRP and VAS ( R = 0.702, P = 0.001). Conclusion: Administration of low doses of ketamine at the end of surgery was more effective in suppressing CRP levels, resulting in lower VAS score, and lower total morphine consumption in the 24-h postoperative period compared to low-dose ketamine given at the time of induction.