Immediate postoperative analgesia and sedation following heart surgery: a comparative analysis of dexmedetomidine chlorohydrate versus remifentanyl hydrochloride

Background

Pain and anxiety are factors contributing to postoperative morbidity, since they are correlated with elevated heart rate and blood pressure, besides increasing peripheral O₂ consumption and serum adrenergic neurohormone levels. Maintaining homeostasis after heart surgery is thus central to the patient's favorable postoperative evolution.

Objectives

This study aims at a comparative analysis of an IV central adrenergic α₂-blocker, dexmedetomidine chlorohydrate, versus a short-acting venous opioid, remifentanyl hydrochloride (RH), with regard to analgesia, sedation and side effects. The primary objective is to identify the most adequate drug for the postoperative ICU setting.

Sample and method

This was a prospective, randomized, open-label study, involving 34 patients, divided into two groups. Group I consisted of 20 patients who received RH at an IV dose of 0.05-0.1 μg/kg/min. Group II consisted of 14 patients who received DC at an IV loading dose of 1 μg/kg in 10 min, followed by infusion at 0.2-0.7 μg/kg/h. Monitoring of analgesia (and sedation) was performed with the following methods: Ramsay Scale (sedation) and Visual-Analogue Scale (VAS) (analgesia). Statistical techniques were exploratory data analysis, Mann-Whitney non-parametric test (95% CI), and Kruskal-Wallis Test (95% CI).

Results

Statistical analysis of data was performed within 10 h after patient admission to the post-operative ICU. Like the Ramsay Scale, VAS, independently of time, showed a significant difference between the two groups (P < 0.001), with group I displaying the lowest values. Over time, group II continued to display lower values, but this difference was not significant (P > 0.1).

Conclusion

Both drugs proved effective for controlling pain and anxiety. RH was more efficient in this control, especially when time was not considered, based on the better results in the first 4 h of the postoperative period. A larger patient sample is needed for more adequate evaluation of the results.