控制心率对鼻内镜手术患者硝酸甘油控制性降压时鼻粘膜血流的影响

Effects of controlled heart rate on nasal mucosa blood flow during nitroglycerin-induced controlled hypotension in patients undergoing endoscopic sinus surgery

目的 评价控制心率（HR）对鼻内镜手术患者硝酸甘油控制性降压时鼻粘膜血流的影响.方法 择期拟行鼻内镜手术患者72例,ASA分级Ⅰ或Ⅱ级,年龄18～45岁,体重49 ～ 85 kg,BMI＜ 30 kg/m2,性别不限,Lund-Mackay评分7-15分,采用随机数字表法分为2组（n=36）：硝酸甘油组（N组）和硝酸甘油控制性降压复合艾司洛尔组（E组）.手术开始前静脉输注硝酸甘油1～3μg·kg-1·min-1行控制性降压,维持MAP为基础值的70％至术毕.E组待MAP降至基础值70％时,静脉输注艾司洛尔20～ 100 μg·kg-1·min-1,根据HR调节用量,维持HR 60 ～ 70次/min至降压结束.于麻醉诱导前（T0）、鼻腔表面麻醉后（T1）、控制性降压15 min（T2）、30min（T3）、45 min（T4）、术毕填塞止血（T5）时记录HR、SV、CO,T1-T4时测定鼻粘膜血流量,同步采集桡动脉血样和颈内静脉球部血样,进行血气分析,计算动静脉血氧含量差（Da-jvO2）、脑氧摄取率（CER02）.采用术野质量评分法评定术野出血量.结果 与N组比较,E组T2-T5时HR、SV和CO、T2-T4时鼻粘膜血流量降低,术野出血量降低（P＜0.01）,Da-jvO2和CERO2差异无统计学意义（P＞0.05）.结论 控制HR（60 ～ 70次/min）可减少鼻内镜手术患者硝酸甘油控制性降压时鼻粘膜血流,且未引起组织灌注不足.

Objective To evaluate the effects of controlled heart rate （HR） on the nasal mucosa blood flow （NMBF） during nitroglycerin （NTG）-induced controlled hypotension in the patients undergoing endoscopic sinus surgery.Methods Seventy-two ASA physical status Ⅰ or Ⅱ patients of both sexes,weighing 49-85 kg,with body mass index 〈 30 kg/m2 and Lund-Mackay score between 7 and 15,scheduled for elective endoscopic sinus surgery,were randomly divided into 2 groups （n =36 each） using a random number table：NTG group （group N） and NTG-induced controlled hypotension combined with esmolol group （group E）.Controlled hypotension was induced with continuous iv infusion of NTG at 1-3 μg· kg-1 · min-1 before surgery,and MAP was maintained at 70% of baseline value until the end of surgery.In group E,when MAP was decreased to 70% of baseline value,esmolol was infused intravenously at 20-100 μg· kg-1 · min-1,the consumption was adjusted according to the HR,and the HR was maintained at 60-70 beats/min until termination of controlled hypotension.Before induction of anesthesia （T0）,after topical anesthesia （T1）,at 15,30 and 45 min of controlled hypotention （T2-4）,and at packing hemostasis at the end of surgery （T5）,HR,stroke volume （SV） and cardiac output （CO） were recorded.NMBF was monitored at T1-T4.Blood samples were drawn from the radial artery and jugular blub at T1-T5 for blood gas analysis.Arteriovenous blood O2 difference （Da-jvO2） and cerebral O2 extraction rate （CERO2） were calculated.The quality of the surgical field in terms of blood loss was rated by the same attending surgeon.Results Compared with group N,HR,SV and CO at T2-T5,NMBF at T2-T4 and the volume of blood loss in the surgical field was significantly decreased in group E （P 〈 0.01）.There was no significant difference in Da-jvO2 and CERO2 between the two groups （P 〉 0.05）.Conclusion Controlled HR （60-70 beats/min） can reduce the NMBF during nitroglycerin-induced controlled hypotension in the patients undergoing endoscopic sinus surgery without causing tissue hypoperfusion.