右美托咪定預防老年高血壓患者全麻氣管插管及拔管時心血管反應的研究

鄭嬋 馮宇峰 孫彩虹

右美托咪定預防老年高血壓患者全麻氣管插管及拔管時心血管反應的研究

鄭嬋 馮宇峰 孫彩虹

目的 探討右美托咪定(dexmedetomidine, Dex)用于老年高血壓患者全麻期間預防氣管插管和拔管時心血管反應的臨床效果及安全性。方法 選擇80例在本院行外科手術ASA Ⅱ～Ⅲ級伴高血壓老年患者, 隨機雙盲分為A(觀察)組(n=40, 氣管插管前靜注0.5 μg/kg Dex)和B(對照)組(n=40, 氣管插管前靜注等量0.9%NS)。記錄兩組患者麻醉誘導前(T0)、誘導后5 min (T1)、插管后即刻(T2)、插管后2 min (T3)、拔管后即刻(T4)、拔管后2 min (T5)等時點的HR、SBP、DBP、SpO2的變化；觀察兩組麻醉時間、拔管時間、患者在PACU1h內意識狀態、麻醉合并癥及不良反應。結果 兩組患者麻醉時間、拔管時間差異無統計學意義。兩組T1及A組其它時間點HR、SBP和DBP與T0比較明顯降低(P＜0.01)；B組在T2、T3、T4和T5等各時點HR、SBP、DBP比T0及A組明顯地升高(P＜0.05, P＜0.01)。在T4和T5時患者嗆咳、體動的發生A組(17.5%)明顯少于B組(47.5%)；安靜入睡者A組(62,5%)顯著高于B組(15%)。兩組其它合并癥及不良反應發生率差異無統計學意義(P＞0.05)。結論 Dex可安全靜脈泵注用于全麻老年高血壓患者, 能有效地預防氣管插管和拔管時的心血管反應。

右美托咪定；老年患者；高血壓；心血管反應；麻醉, 全身

全麻氣管插管及蘇醒拔管時因刺激交感神經致兒茶酚胺分泌增多, 引起BP增高、心動過速, 導致心肌氧耗增加；特別是高血壓、冠心病患者更易加重心臟負荷、干擾心臟氧供需平衡, 增加患者心率失常及心腦血管意外的風險。右美托咪定 (dexmedetomidine, Dex) 是一種強效高選擇性α2-腎上腺素能受體(α2-AR)激動劑, 有較強的抗焦慮、鎮靜、鎮痛、抑制交感神經系統活動等作用, 目前廣泛用于臨床麻醉。本研究旨在觀察Dex對老年高血壓患者全麻氣管插管和拔管期間心血管反應的影響。現報告如下。

1 資料與方法

1.1 一般資料 選擇2011年08月～2013年06月在本院住院擬在氣管插管全麻下行外科手術80例老年伴高血壓患者, ASAⅡ～Ⅲ級；其中男性53例, 女性27例, 年齡65～81歲, 體重52～75 kg, 身高 155～178 cm；手術時間≤4 h；按隨機數字表法隨機雙盲分為A (觀察) 組和B (對照) 組, 每組各40例。所有患者術前經心內科會診對癥處理, BP控制≤160/90 mmHg, 無嚴重心腦肺肝腎功能障礙、心臟傳導阻滯、心動過緩、嚴重貧血及神經系統疾病。

1.2 麻醉方法 本研究經本院倫理委員會討論批準, 獲得患者及家屬書面知情同意簽字。患者入室后開放靜脈輸液,麻醉前30 min均靜脈注射阿托品0.5 mg, 局麻下橈動脈穿刺,常規監測ECG、SBP、DBP、HR、SpO2和PETCO2。A組在氣管插管前30 min以0.5 μg·kg-1·h-1微量泵靜脈輸注Dex, 15 min注射完畢后停止泵注。B組則在相同時段內靜脈輸注等容量0.9%N.S。麻醉誘導：靜注咪達唑侖0.05 mg/kg、順式阿曲庫銨0.2～0.3 mg/kg、依托咪酯0.15～0.2 mg/kg及芬太尼3～4 μg/kg, 氣管插管后接麻醉機行IPPV, 常規設定機械通氣指標。麻醉維持：微量泵靜注丙泊酚(Propofol, Pro.) 4～8 mg·kg-1·h-1、瑞芬太尼4～8 μg·kg-1·h-1, 酌情靜脈注射順式阿曲庫銨維持麻醉。兩組患者術畢帶氣管導管送恢復室(PACU)觀察, 患者蘇醒、拔除導管, 生命體征平穩后, 安全送回病房。

1.3 氣管插管期間及在PACU觀察指標 ①記錄兩組患者麻醉誘導前(T0)、誘導后5 min (T1)、插管后即刻(T2)、插管后2 min (T3)、拔管前(T4)、拔管后2 min (T5)等時點的HR、SBP、DBP、SpO2的變化；②觀察兩組麻醉時間、拔管時間、患者在PACU1h內意識狀態、麻醉合并癥及不良反應。

1.4 統計學方法 采用SPSS 13.0統計軟件進行統計學分析。所有計量資料以均數±標準差(±s)表示；組間計量資料比較采用t檢驗；計數資料以χ2檢驗；等級資料比較采用秩和檢驗。P＜0.05為差異有統計學意義。

2 結果

2.1 一般資料比較 兩組患者ASA分級、年齡、性別、體質量、麻醉時間和拔管時間比較差異無統計學意義(P＜0.05)。

2.2 兩組插管及拔管期間HR、BP比較 兩組誘導后及A組其它時間點HR、SBP和DBP與麻醉誘導前比較明顯降低(P＜0.01)；B組HR、SBP、DBP較麻醉誘導前及A組不同時間點明顯升高(P＜0.05, P＜0.01) B組在T2、T3、T4和T5等各時點HR、SBP、DBP比T0及A組明顯地升高(P＜0.05)。見表1。

表1 兩組患者HR、BP的變化±s)

表1 兩組患者HR、BP的變化±s)

注：與T0比較,aP＜0.05,cP＜0.01；與A組比較,bP＜0.01 (1 mmHg=0.133 kPa)

項目組別例數T0T1T2T3T4T5HR(bpm)A組4081.2±9.361.7±6.9c78.1±8.0c71.6±9.5c69.3±7.2c68.7±9.4cB組4080.7±9.462.2±7.4c95.5±10.1ab102.2±9.9ab99.6±9.7ab98.5±9.3abSBP(mmHg)A組40149.6±7.5106.9±9.7c108.1±10.6116.7±9.5118.4±7.8120.0±8.7 B組40148.8±7.4107.8±9.3c142.7±9.3b145.6±11.7b142.8±9.2b140.2±10.1bDBP(mmHg)A組4082.4±7.659.8±7.5c62.6±6.4c70.1±6.3c71.9±6.4c72.4±7.7cB組4081.7±7.358.3±7.7c80.1±6.5b83.4±7.2b82.3±6.4b82.8±6.1b

2.3 在PACU拔管時A組有17.5%(7例/40例)出現嗆咳、體動, B組47.5%(19例/40例),兩組比較, 差異有統計學意義(P＜0.01)；拔管后A組安靜入睡者62.5%(25例/40例), B組為15%(6例/40例), 兩組比較差異有統計學意義(P＜0.01)。兩組均無惡心、嘔吐、低氧血癥、躁動、譫妄等并發癥。

3 討論

老年患者的循環系統順應性下降, 血管彈性降低, 阻力增加, 導致BP升高、左室肥厚、心室舒張功能減退、心臟儲備功能減少［1］。全麻氣管插管因置入喉鏡暴露聲門、氣管插管及套囊充氣等操作對呼吸道引起機械性刺激, 激活腎上腺能系統及血管緊張素系統, 導致腎上腺髓質釋放兒茶酚胺使BP升高、HR增快, 增加耗氧量, 加重心血管負擔［2］。文獻報道氣管插管后BP上升30%, HR增快20%［3］, 可使心肌耗氧增加明顯, 對缺氧的耐受性下降, 對心肺功能降低的老年患者很不利。因此, 預防氣管插管和拔管時心血管反應的增加, 維持循環穩定, 對提高患者圍術期的安全性非常重要。

Dex通過激動中樞突觸后和交感神經末梢的突觸前α2-AR, 抑制麻醉和手術操作引起的交感神經發放沖動, 使交感神經張力和血漿兒茶酚胺濃度下降［4］； Dex對血流動力學的影響, 受劑量和給藥速度的影響［5］。快速給予Dex負荷劑量1 μg/kg, 可直接激活血管平滑肌內的α2-AR, 血管收縮, 引起BP一過性升高, HR反射性地降低；而緩慢給藥, 時間超過10 min, 可減弱此反應。本研究顯示A組給予靜脈泵注Dex后, BP、HR變化不大, 而麻醉誘導后兩組HR、SBP及DBP均降低,這與患者術前禁食禁水、血容量相對不足及麻醉誘導藥物對心血管有一定抑制作用有關。文獻報道對婦科和腹部外科手術的患者, 術前經靜脈或肌注給予Dex 1.2～2.4 μg/kg, 能夠降低氣管插管及手術引起的應激反應［6］。本研究A組雖然氣管插管前30 min僅以0.5 μg·kg-1·h-1微量泵靜脈輸注Dex,但在插管、拔管及術中HR、SBP、DBP相對穩定, 與老年患者對藥物耐受性較弱有關；說明靜注Dex對非心臟手術的患者能起到心肌保護作用［7］, 能抑制氣管插管引起的心血管反應；而B組在插管和拔管期間HR、SBP及DBP則明顯加快、升高, 雖然此反應為一過性的, 但對有潛在心臟疾患甚至正常心肌易造成損害, 引起心肌缺血、心律失常, 增加了麻醉意外風險。

Dex分布半衰期約為6min, 消除半衰期約為2 h。Dex作用于中樞藍斑核α2-AR而發揮鎮靜、催眠、抗焦慮作用［8］。本研究中A組患者在PACU拔管時發生嗆咳、體動明顯少于B組；A組安靜入睡者明顯高于B組；兩組均無惡心、嘔吐、低氧血癥、躁動、譫妄等并發癥。說明Dex能安全用于老年患者, 且Dex的抗焦慮、鎮靜、催眠作用能顯著緩解老年患者術后緊張、恐懼情緒。

綜上所述, Dex可安全靜脈泵注用于全麻老年高血壓患者, 蘇醒期安靜, 并發癥少, 能有效地預防氣管插管和拔管時的心血管反應。

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Study of dexmedetomidine on prevention of the cardiovascular response during intubation and extubation in old aged patients with hypertension in general anesthesia

ZHENG Chan, FENG Yu-feng, SUN Cai-hong.
Department of Anesthesiology, First Affiliated Hospital of Xiamen University, Xiamen 361003, China

Objective To investigate the clinical effects and safety of dexmedetomidine (Dex) on prevention of the cardiovascular response during intubation and extubation in old aged patients with hypertension in general anesthesia. Methods 80 elective old aged patients with hypertension, ASA grade II～Ⅲ, undergoing surgery under general anesthesia were double-blinded randomly allocated to two groups with 40 cases each. Group A (n = 40)

Dex 0.5 μg/kg and group B (n=40) received the same volume normal saline. HR, SBP, DBP were recorded before anesthesia (T0), after induction (T1), at the time of intubation(T2),3 min after intubation (T3), at the time of extubation (T4) and3 min after extubation (T5). The complications and adverse reactions of anesthesia were recorded during each operation. anesthetic time、extubation time and patients` consciousness in1 hour during PACU were observed and recorded. Results Anesthetic time and extubation time were not significantly different in the two groups (P＞0.05). HR、SBP、DBP were found significantly lower than baseline at the time of T1in both groups and at other time point in group A (P＜0.01).HR、SBP、DBP were significantly higher than T0and group A at each point of T2、T3、T4and T5in group B (P＜0.05 or P＜0.01). The patients' choke and body movement in group A (17.5%) were found significantly lower than those in group B(47.5%). Quiet fall asleep cases were found significantly higher in group A (62.5%) than that in group B (15%). The incidence of complications and adverse reactions in both groups ware not significant (P＞0.05). Conclusion It is safety to pump intravenous injection Dex for old aged patients with hypertension undergoing surgery in general anesthesia. It can be effective in preventing cardiovascular response during intubation and extubation.

Dexmedetomidine; Elderly Patients; Hypertension; Cardiovascular response; Anesthesia; General

361003 廈門大學附屬第一醫院麻醉科(鄭嬋馮宇峰), 麻醉科恢復室(孫彩虹)

馮宇峰