Correlation of post-operative pain and levels of creatin phosphokinase enzyme following ovariohysterectomy in cats

Abstract

Background: Recognition of pain is challenging in veterinary medicine due to lack of verbal communication and universal pain assessment system. Increase in biochemical parameters have been shown to have direct correlation with level of postoperative pain. Objectives: The purpose of the present study is to evaluate the serum levels of CPK and investigate any correlation in serum levels of CPK and postoperative pain following ovariohysterectomy in feline. Methods: Conventional midline ovariohysterectomy was performed in 24 healthy female queens. Serum levels of cortisol, CPK and glucose were measured prior to surgery and at 1 and 3 and 24 hours after the surgery. Also, VAS was used to assess level of post-operative pain. Data was analyzed using repeated measure ANOVA. Spearman’s rank correlation coefficient was used to identify any correlation between level of pain and CPK after the surgery. Results: The score of pain significantly increased at 1 and 3 hours after the surgery in all of the cats (p=0.001).The concentration of cortisol and CPK significantly increased after the surgery in comparison to the values prior to surgery (p<0.001). Also, the concentrations increased significantly at 3 hours after the surgery compared to the values at 1 hour after the surgery (p<0.001). In 24 hours after the surgery results revealed that serum level of cortisol returned to its normal values but CPK was still higher compared to the values prior to surgery. Significant correlation was detected between the level of pain and CPK after surgery (p<0.05). Conclusions: It is concluded that there is a correlation with VAS score of pain and serum levels of Cortisol and CPK at early hours after the surgery. CPK might be used as an indicator of pain in early hours after the surgery in feline. However, the assessment of pain in cats is not possible based on its values alone.