اثر انفوزيون دوز كم كتامين بر روي تغييرات قلبي عروقي رمي فنتانيل در طي بيهوشي عمومي : كارآزمايي باليني تصادفي

The effect of low-dose ketamine infusion on the remifentanil induced hemodynamic changes during general anesthesia

Background: Remifent anil is known to produ ce side-effects of hyp otens ion and bradycardi a. In thi s study , we examine the effec t of low-dose ketamine infu sion on the heart rate and blood pressure of pati ent s anes thet ized with remi fent ani l. Methods: In a randomi zed clini cal trial, 54 pat ient s aged 20-50 yea rs old, with ASA physical status T, were studied in two groups (n=27), Ketamine- Remifentanil (K-R group) and Placeb o- Rernifent anil (P-R group). Exc lusi on criteria were ASA physical status >1, gastroesophageal reflux, tach ycard ia, bradycardi a, sys temic disease s, use of antihypertensive dru gs, diffi cult intuba tions, risk of aspiration and contra indications of ketamin e. Remi fent anil was started at a rate of 0.5 ug, kg"l. min " and anes thes ia was induced with thiopental sodium 2 mg.k gʹ . Maintenance of anes thes ia included hal oth ane and nitrous oxide/oxyge n mixtu re. Remifent anil infus ion was co ntinue d in both gro ups at a rate of 0.5 Ilg.kg·ʹ.min, l. In the K-R group, ketamine was s tarted wi th an infus ion rate of 10 ug.kg". minʹ , 10 minutes afte r intub ati on, while in the P-R group , normal sa line was started with the same dose of remifentan il, Heart ra te, systo lic, diastoli c and mean arteria l blood pressure were measur ed and compared at 1, 3, 5, 10, 15, 20. 25 and 30 minutes. Results: No signi ficant differences we re found between basic pat ient chara ct eristi cs of mean of age, sex, weight, systo lic, diastolic and mean arte ria l blood pressure and heart rate (p>0.2) in the two groups. However, the ra te of sys tolic, diastoli c and mean arteria l blood pressure cha nges in the P-R gro up was significantly greater than that of the K-R grou p (p<0.006). Heart rate changes were similar between the two groups (p=0 .6). Incident of severe hypotension (a decrease of more than 25% of tbe basic va lue) was less in the K-R group than that of the P-R group ( I I% vs, 89%; p=O.OOO). Conclusion: Low-dose ketamine infusion modul ates the effe ct of rem ifent anil-induced hypotension and provid es bett er hemod ynami c stability dur ing genera l anesthes ia.