Evaluationof Functional Endoscopic Sinus Surgery After Pre-operative Intravenous Infusion Of Dexmedetomidine

【Objective】. To evaluate the surgical field，blood loss, extuationquality score and Ramsay score with pre-operative intravenous infusion ofdexmedetomidine for functional endoscopic sinus surgery(FESS)and todiscussthe influence factors of FESS`s visibility of visual fields.【Methods】40patients of ASA class I or II,aged15-65years old,undergoing functional endoscopic sinus surgery under general anesthesia wererandomly assigned into two groups, one group (group D) received anintravenous infusion of dexmedetomidine before surgery, while the other(group C) was the control group with the same amount of normal saline.TheMAP of both groups was maintained at about70mmHg.HR was observedbefore operation (T0),10minutes after infusion (T1),right after intubation(T2), the beginning of procedure (T3),15minutes after surgery (T4),30minutes after surgery (T5),45minutes after surgery (T6),60minutes aftersurgery (T7),75minutes after surgery (T8),90minutes after surgery (T9),105minutes after surgery (T10),120minutes after surgery (T11). TheFromme score was recorded every15minutes from15minutes after surgery to120minutes after surgery, noted as Fromme scores for operation15minutes(F1),operation30minutes (F2), operation45minutes (F3), operation60minutes (F4), operation75minutes (F5), operation90minutes (F6),operation105minutes (F7), operation120minutes (F8). The modifiedLund-Kennedy score (LMK), the operation time,the blood lose,and the levelsof hemoglobin and hematocritwere recordedbefore and one day after surgery.The scores of extubation quality were recorded right after extubation, andthe Ramsay scores were taken30minutes after extubation, observing whether the two groups of patients had adverse effects,such as reflex hypertension,hypotension, bradycardia, and ST segment depression.【Results】There was no significant difference between thetwo groups ofpatients withoperationtime andthe classification of MLK, HRat T0(P>0.05).Comparedwith group C,after T0,at every point in time,the meanheartratewere relativelylower.InT2-T9twogroup`smean HR were with statisticalsignificance difference(P＜0.05).Prematurebeats,sinusbradycardia,andSTsegment depressionwere notoccurred in ECGrecording of two groups,thetwo groups had noreflex hypertension,hypotension aswell.Comparedwithgroup C,from F1to F8,the meanFromme scoreswererelatively lower,especially from F2to F6(P<0.05). And also, the blood losswas less in group D(P<0.05).In addition,blood loss andMLKgradingwerepositively correlatedin both groups,furthermore the heart rate and surgicalfield`s visibility were positive correlation,and the differences were statisticallysignificant(P<0.05).Compared with the preoperative condition, both of thegroups`Hb, Hct were decreased with significant difference (P＜0.05）.Compared with group C, preopetiveHb-postoerativeHb and preopetiveHct-postoerativeHctwere relatively low with significant difference (P＜0.05). Nosignificant differences between the two groups of patients with extubationtime ((P＞0.05). Group D`s extubation quality score was significantly higherthan that in group C, while the Ramsay score,which was evaluated30minutesafter extubation, was significantly higher than that in group C withstatistically difference (P＜0.05). Patients in two groups hadnonausea,vomiting,hypertension,hypotension,bradycardiaand other adversereactions after operation.【Conclusions】Preoperative intravenous infusion of dexmedetomidinecould improve the surgical field and extubation quality score withoutprolonging extubation time. The higher MLK classification is, the more bloodloss would be. When the MAP was maintained at the same level, the lowerHR would provide a better visibility for the FESS.