Relationship between neutrophil-lymphocyte ratio and postoperative pain in cesarean section patients done under...

Cesarean section is one of the most commonly performed surgeries in obstetrics. Various methods have been employed to assess postoperative pain. Surgical trauma causes acute phase response with neutrophilia and relative lymphopenia. Hence neutrophil lymphocyte ratio (NLR) can be taken as an objective tool to measure acute pain. The primary objective of the study was to evaluate the relationship between postoperative NLR and pain, which was assessed using visual analogue scale (VAS).

A prospective observational study was conducted on 120 pregnant women aged between 18 to 38 years belonging to American Society of Anesthesiologists Physical Status II undergoing elective cesarean section under subarachnoid block, in a tertiary care hospital over 18 months. Postoperatively pain was assessed using VAS. Blood samples were sent and NLR was calculated preoperatively and postoperatively. Injection diclofenac and tramadol was administered for postoperative pain and total doses of respective drugs were noted. The correlation between NLR and VAS was assessed using Spearman's rank correlation analysis.

The postoperative NLR was higher than the preoperative NLR. There was significant correlation between VAS score and NLR score at 12^th, 24^th and 48^th h [(Spearman's rank correlation coefficient), r = 0.462, P < 0.001; r = 0.519 P < 0.001; r = 0.455 P < 0.001]. The diclofenac requirement was significantly high at 24 h among the repeat cesarean section patients (P = 0.023).

The postoperative NLR correlated significantly with VAS. NLR can be used as a surrogate marker for pain assessment.