Attenuation of the pressor response to tracheal intubation with oral nitrendipine

The effect of nitrendipine on the cardiovascular responses to tracheal intubation was studied in a placebocontrolled, randomised, double–blind trial. Thirty patients (ASA physical status 1) undergoing elective surgery either 5 or 10 mg nitrendipine, or a placebo orally 3 h before induction of anaesthesia (n = 10 for each group). Anaesthesia was induced with sodium thiopentone 5 mg/kg i.v. and tracheal intubation was facilitated with vecuronium 0.2 mg/kg i.v. Patients receiving the placebo showed a significant increase in the mean arterial pressure and the rate–pressure product in response to tracheal intubation. These increases following intubation were reduced in nitrendipine–treated patients compared with the placebo group (P < 0.05). Oral administration of nitrendipine (5 or 10 mg, 3 h before induction of anaesthesia) was able to attenuate the hypertensive response to tracheal intubation in ASA 1 patients under light anaesthesia. We propose this pharmacological technique with supplementary doses of opioids and/or benzodiazepines for the management of patients with hypertension or coronary artery disease.     

右美托咪定对全麻患者气管插管时血流动力学变化的影响

目的 探讨右美托咪定对全麻患者气管插管时血流动力学变化的影响.方法 择期手术患者40例,随机分为M1、M2组,M1组麻醉诱导前给予右美托咪定0.5μg/kg,再以0.3 μg/（kg·h）速度持续输注.两组均给予咪达唑仑、芬太尼、丙泊酚、罗库溴铵麻醉诱导,气管插管.记录患者入室后、麻醉诱导前、插管前、插管即刻、插管1、3、5 min后的血压、心率.结果 M1组输注右美托咪定后,HR较基础值明显降低;麻醉诱导后各观察时刻,BP较基础值明显减低;M2组HR插管前低于基础值,插管后1 min大于基础值,BP在插管前与插管即刻明显小于基础值;M1组HR自诱导前各观察时刻、BP自插管时各观察时刻均低于M2组;M1组麻醉药诱导用量明显少于M2组.结论 麻醉诱导前给予右美托咪定0.5 μg/kg可较完善地抑制插管时的心血管反应,减少麻醉药用量.     

Partial attenuation of hemodynamic responses to rapid sequence induction and intubation with labetalol

The effectiveness of labetalol (a combination nonselective beta and alpha-1-adrenergic receptor antagonist) in modifying hemodynamic responses associated with rapid sequence induction and tracheal intubation was evaluated. In a double-blind study, 24 ASA physical status I or II male patients scheduled for elective surgery were given either IV labetalol, 0.25 mg/kg (n = 8) or 0.75 mg/kg (n = 8), or a saline placebo (n = 8). Five minutes later, patients were given oxygen by mask and IV vecuronium, 0.01 mglkg. Ten minutes after giving labetalol or placebo, cricoid pressure was applied and anesthesia was induced with IV sodium thiopental (4 mg/kg) and succinylcholine (1.5 mg/kg) 1 minute prior to intubation. The mean duration of laryngoscopy was 17 ± 3 seconds. Prior to induction, the 0.25 mg/kg and 0.75 mg/kg) doses of labetalol significantly (p < 0.05) reduced mean arterial pressure by 4.4 ± 1.9 and by 8.6 ± 2.0 mmHg, respectively, but did not significantly alter heart rate or cardiac output. The 0.75 mg/kg) dose of labetalol also significantly (p < 0.05) decreased total peripheral resistance by 10.1 ± 3.0%. Within 30 seconds after intubation, patients in all three groups exhibited increases in heart rate, mean arterial pressure, total peripheral resistance, and rate pressure product and a decrease in stroke volume. However, patients in the 0.25 and 0.75 mg/kg) labetalol groups, compared to those in the placebo group, had significantly lower increases in peak heart rate (33 ± 2 and 27 ± 3 vs. 44 ± 7 beats/minute), peak mean arterial pressure (38 ± 6 and 38 ± 7 vs. 58 ± 7 mmHg), and peak rate pressure product (7,726 ± 260 and 7,215 ± 300 vs. 14,023 ± 250 units). The results show that these doses of labetalol significantly blunt, but do not completely block, autonomic responses to rapid sequence induction and intubation.     

Partial attenuation of the cardiovascular responses to tracheal intubation with oral nisoldipine.

STUDY OBJECTIVE: To evaluate the efficacy and safety of nisoldipine given orally in attenuating the cardiovascular responses to laryngoscopy and tracheal intubation. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Induction of anesthesia for elective surgery at a university hospital. PATIENTS: Thirty normotensive patients (ASA physical status I) undergoing elective surgery were assigned to one of three groups; placebo, nisoldipine 5 mg, or nisoldipine 10 mg. Each group consisted of ten patients. INTERVENTIONS: Either 5 mg of nisoldipine, 10 mg of nisoldipine, or a placebo was administered orally 2 hours before induction of anesthesia. Anesthesia was induced with thiopental sodium 5 mg/kg intravenously, and tracheal intubation was facilitated with vecuronium 0.2 mg/kg. During anesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide in oxygen. Laryngoscopy lasting 30 seconds was attempted 2 minutes after administration of thiopental sodium and vecuronium. MEASUREMENTS AND MAIN RESULTS: Patients receiving the placebo showed a significant increase in mean arterial pressure associated with tracheal intubation. These increases following tracheal intubation were significantly reduced in patients receiving nisoldipine 10 mg compared with patients receiving the placebo (p less than 0.05). CONCLUSIONS: Oral administration of nisoldipine before induction of anesthesia is a simple, practical, and safe method for attenuating pressor response to laryngoscopy and tracheal intubation.     

Effects of nicardipine on the circulatory responses to tracheal intubation in normotensive and hypertensive patients

This study was undertaken to examine the effects of nicardipine on circulatory responses to laryngoscopy and tracheal intubation in normotensive (n = 39) and hypertensive (n = 36) patients. Laryngoscopy and tracheal intubation were performed after induction of anaesthesia with thiamylal, followed by administration of intravenous saline or nicardipine 20 or 30 micrograms.kg-1 and suxamethonium. Blood pressure and heart rate were recorded, and rate-pressure product was calculated. Nicardipine 20 and 30 micrograms.kg-1 prevented the increase in mean arterial pressure after intubation in normotensive and hypertensive patients (p less than 0.01 compared with saline). The changes in heart rate after intubation were significantly greater in normotensive patients than in hypertensive patients when 20 or 30 micrograms.kg-1 of nicardipine was given (p less than 0.05 and p less than 0.01 respectively). Rate-pressure product increased significantly (p less than 0.01) after intubation in normotensive patients whether nicardipine was administered or not, but the increase was suppressed completely by nicardipine 20 or 30 micrograms.kg-1 in hypertensive patients. We conclude that nicardipine is effective in preventing the circulatory responses to laryngoscopy and tracheal intubation in hypertensive patients.     

Pretreatment with oral clonidine attenuates cardiovascular responses to tracheal extubation in children

This study was designed to evaluate the effects of diazepam and clonidine orally given preoperatively on cardiovascular responses to tracheal extubation in children. Fifty children, ASA physical status I, aged 4-10 years, undergoing minor elective surgery (inguinal hernia, phimosis) received orally, in a randomized, double-blind manner, diazepam 0.4 mg.kg-1 or clonidine 4 microgram.kg-1 (n=25 of each). These drugs were administered 105 min before an inhalational induction of anaesthesia. The same standard general anaesthetic technique was employed throughout. The maximum changes in heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were less in patients who had received clonidine than in those who had received diazepam (HR, 12 vs 24; SBP, 14 vs 26; DBP, 9 vs 16; mean, P < 0.05). In conclusion, compared to diazepam given orally, pretreatment with oral clonidine attenuates haemodynamic changes associated with tracheal extubation in children.     

注药型气管导管表面麻醉抑制气管插管心血管反应临床研究

目的 观察"声门上下注药型气管导管"(专利号:ZL 200820111377.4)在全身麻醉气管插管后立刻注射表面麻醉药能否减轻气管插管的心血管反应.方法 择期骨科手术患者40例,ASA分级Ⅰ、Ⅱ级,年龄20~60岁,BMI 22~30 kg/m2,按随机数字表法分为试验组和对照组,每组20例.以咪达唑仑0.04 mg/kg、舒芬太尼0.2μg/kg、依托咪酯0.25 mg/kg和维库溴铵0.1 mg/kg麻醉诱导,手控呼吸3 min后30 s内完成经口插入声门上下注药型气管导管,试验组立即注射1%丁卡因1.5 ml(声门下即气管内1 ml,声门上即咽喉部0.5 ml)施表面麻醉,对照组不注射药.固定导管,接麻醉机通气.分别于入室安静时(基础值,T0)、插管前即刻(T1)、插管后即刻(T2)、插管后1 min(T3)、插管后3 min(T4)和插管后5 min(T5)记录BP、HR和抽取血液标本测定血浆肾上腺素(epinephrine,E)、去甲肾上腺素(noradrenaline,NE)、皮质醇(cortisol,Cor)水平.结果 试验组SBP仅在T2时较T0时显著升高17%(P<0.05),对照组SBP在T2、T3、T4时分别较T0时显著升高29%(P<0.01)、36%(P<0.01)、15%(P<0.05);在T2~T5时,试验组SBP比对照组明显降低(P<0.05).试验组HR插管后没有显著升高(P>0.05),而对照组HR在T2、T3时分别显著升高18%(P<0.01)和14%(P<0.05),组间比较差异有统计学意义(P<0.05).试验组血浆E水平在T3和T5时明显较对照组低(P<0.05),血浆NE水平在T3和T5时试验组明显较对照组低(P<0.05).试验组血浆Cor水平在T5时明显较对照组低(P<0.01).结论 使用注药型气管导管在插入时立即注射表面麻醉药实施气管内、咽喉表面麻醉,能明显降低气管插管引起的心血管反应.     

不同剂量瑞芬太尼复合异丙酚的气管插管条件及血流动力学的变化

喉镜置入和气管插管常可引起心动过速、高血压、心律失常、血浆儿茶酚胺浓度升高及敏感患者的心肌缺血、动脉瘤破裂等，可能导致对机体的损伤。采用静脉注射阿片类药物可以抑制机体的应激反应。异丙酚是一种起效快的新型麻醉药，广泛应用于麻醉诱导和麻醉维持。瑞芬太尼具有理想的阿片类受体激动剂特性和独特的药理学特点，现已广泛应用于临床麻醉诱导和维持。异丙酚复合瑞芬太尼用于麻醉诱导，既能使麻醉达到一定深度，又能减轻气管插管的心血管反应。本研究以血压、心率及患者的反应作为观察指标，旨在观察不同剂量瑞芬太尼复合异丙酚麻醉诱导后气管插管条件及血流动力学的变化，为临床合理应用瑞芬太尼提供参考。     

Effects of prostaglandin E1 on the cardiovascular response to tracheal intubation

Study Objective: To evaluate the efficacy of prostaglandin E, in attenuating the hypertensive response to laryngoscopy and intubation.

Design: Controlled, comparative, and randomized study.

Setting: Induction of anesthesia for elective surgery at a university hospital.

Patients: Thirty normotensive patients (ASA physical status I) undergoing elective surgery divided into three groups. Each group consisted of ten patients.

Interventions: Anesthesia was induced with thiopental sodium 5 mglkg intravenously, and tracheal intubation was facilitated with vecuronium 0.2 mglkg. Either 0.3 μglkg of prostaglandin E₁, 0.6 μg/kg of prostaglandin E₁, or saline (control) was injected 15 seconds before starting direct laryngoscopy (within 30 seconds), which was attempted 2 minutes after administration of thiopental sodium and vecuronium.

Measurements and Main Results: Patients receiving saline showed a significant increase in mean arterial pressure and rate-pressure product associated with tracheal intubation. These increases following tracheal intubation were significantly less in prostaglandin E₁-treated patients than in the control group (p < 0.05).

Conclusions: A single rapid intravenous administration of prostaglandin E₁ is a practical pharmacologic and safe method to attenuate the hypertensive response to tracheal intubation. The use of 0.6 μglkg of prostaglandin E₁ as a supplement during induction is recommended for reducing the pressor response to intubation on the basis of rate-pressure product and mean arterial pressure , following intubation as an index.     

The effect of sufentanil on the cardiovascular responses to tracheal intubation

The effects of sufentanil 0.5 or 1 microgram/kg, given intravenously after induction of anaesthesia, on the cardiovascular responses to tracheal intubation were examined in a controlled, randomised, double-blind investigation. The control group of patients exhibited significant rises in arterial blood pressure and heart rate for 4 minutes after tracheal intubation. Heart rate exceeded 100 beats/minute and systolic pressure increased by over 20% in every patient. All patients moved or breathed within 10 minutes of the administration of suxamethonium. Sufentanil 0.5 microgram/kg prevented increases in the mean values of heart rate and arterial blood pressure, although increases were observed in five patients. Significant falls in the mean values of heart rate and arterial pressure occurred from 4 minutes after intubation until observations ended 15 minutes after induction of anaesthesia. Two patients moved or breathed during this time, although movement in response to nerve stimulation occurred in all patients 10 minutes after administration of suxamethonium. Sufentanil 1 microgram/kg was effective in suppressing a rise in heart rate or arterial pressure in every patient. Significant falls in these variables occurred from 2 minutes after tracheal intubation onwards. No patient moved or breathed for 15 minutes after induction of anaesthesia, although neuromuscular transmission was present 10 minutes after giving suxamethonium in each case.     

阿片类药物用于抑制气管内插管副反应时合理给药时机优于药物种类和剂量的选择

已经证明芬太尼能很好地抑制气管插管的心血管副反应。舒芬太尼是芬太尼的N-4噻吩基衍生物,与阿片受体的亲和力较芬太尼强,镇痛作用是芬太尼的10倍,而且作用持续时间也更长。瑞芬太尼是一种新型μ阿片受体激动剂,具有起效迅速、作用时间短、镇痛作用与芬太尼近似、恢复迅速、无     

Effects of beta-adrenoceptor antagonism on the cardiovascular and catecholamine responses to tracheal intubation

The catecholamine and cardiovascular responses to laryngoscopy and tracheal intubation were studied in 20 patients who underwent elective gynaecological surgery and who were allocated randomly to receive either practolol 10 mg or saline intravenously prior to induction of anaesthesia. Anaesthesia was induced with fentanyl and thiopentone; atracurium was administered and the lungs were ventilated artificially with 67% nitrous oxide in oxygen. Tracheal intubation was performed when muscle relaxation was adequate. Arterial pressure, heart rate, plasma noradrenaline and adrenaline concentrations were measured before and after tracheal intubation. A significant increase in catecholamine concentrations occurred in both groups in response to tracheal intubation but the magnitude of the increase in adrenaline was greater in the practolol group. There were no significant differences in arterial pressure or heart rate changes between the groups. We conclude that pretreatment with practolol is of no value in the attenuation of the hypertensive response to direct laryngoscopy and tracheal intubation in previously normotensive patients.     

Effect of prophylactic bronchodilator treatment with i.v. carperitide on airway resistance and lung compliance after tracheal intubation

Background. Lung resistance increases after induction of anaesthesia.We hypothesized that prophylactic bronchodilation with i.v.carperitide before tracheal intubation would decrease airwayresistance and increase lung compliance after placement of thetracheal tube in both smokers and nonsmokers. Methods. Ninety-seven adults aged between 24 and 59 yr wererandomized to receive i.v. normal saline (0.9% saline) (control)or carperitide, 0.2 µg kg^–1 min^–1 throughoutthe study. The 97 patients included smokers and nonsmokers.Thus the patients were allocated to one of the four groups:smokers who received normal saline (n=21), nonsmokers who receivednormal saline (n=27), smokers who received carperitide (n=19)or nonsmokers who received carperitide (n=30). Thirty minutesafter starting normal saline or carperitide infusion, we administeredthiamylal 5 mg kg^–1 and fentanyl 5 µg kg^–1to induce general anaesthesia and vecuronium 0.3 mg kg^–1for muscle relaxation. Continuous infusion of thiamylal 15 mgkg^–1 h^–1 followed anaesthetic induction. Mean airwayresistance (R_awm), expiratory airway resistance (R_awe) and dynamiclung compliance (C_dyn) were determined 4, 8, 12 and 16 min aftertracheal intubation and compared between the four groups. Results. At 4 min after intubation, R_awm and R_awe were higherand C_dyn lower in smokers than in nonsmokers in the controlgroup. R_awm and R_awe were lower and C_dyn higher in smokers inthe carperitide group than in smokers in the control group.R_awm and R_awe were lower in nonsmokers in the carperitide groupthan in nonsmokers in the control group. Conclusions. Marked bronchoconstriction occurred in the controlgroups (smokers and nonsmokers) 4 min after tracheal intubation.Prophylactic treatment with carperitide before induction ofanaesthesia and tracheal intubation was advantageous, particularlyin smokers.     

Gabapentin attenuates the pressor response to direct laryngoscopy and tracheal intubation

Background. Laryngoscopy and tracheal intubation increase bloodpressure and heart rate (HR). The aim of the present study wasto investigate the effect of gabapentin when given before operationon the haemodynamic responses to laryngoscopy and intubation. Methods. Forty-six patients undergoing abdominal hysterectomyfor benign disease were randomly allocated to receive gabapentin1600 mg or placebo capsules at 6 hourly intervals starting theday (noon) before surgery. Anaesthesia was induced with propofoland cis-atracurium. Systolic, diastolic arterial blood pressures(SAP, DAP) and heart rate (HR) were recorded before and afterthe anaesthetic and 0, 1, 3, 5 and 10 min after tracheal intubation. Results. SAP was significantly lower in the gabapentin vs thecontrol group 0, 1, 3, 5 and 10 min after intubation [128 (27)vs 165 (41), P=0.001, 121 (14) vs 148 (29), P=0.0001, 115 (13)vs 134 (24), P=0.002, 111 (12) vs 126 (19), P=0.004 and 108(12) vs 124 (17), P=0.001 respectively]. DAP also was lowerin the gabapentin group 0, 1, 3, and 10 min after intubation[81 (18) vs 104 (19), P=0.0001, 77 (9) vs 91 (16), P=0.001,71 (10) vs 84 (13), P=0.001 and 67 (10) vs 79 (12), P=0.004].HR did not differ between the two groups at any time [82 (11)vs 83 (15), 79 (10) vs 80 (12), 86 (17) vs 92 (10), 82 (11)vs 88 (10), 81 (12) vs 81 (11), 77 (13) vs 79 (13), and 75 (15)vs 78 (12)]. Conclusion. Gabapentin, under the present study design attenuatesthe pressor response but not the tachycardia associated withlaryngoscopy and tracheal intubation.     

Submandibular approach for tracheal intubation in patients with panfacial fractures

Background: The oral route for tracheal intubation can interfere with somemaxillofacial surgical procedures. At the same time, the nasalroute can be contraindicated or impossible. Tracheostomy isthe usual solution in these circumstances, but it carries ahigh incidence of complications. We tested the submandibularroute for tracheal intubation as an alternative to tracheostomyin such situations. Methods: The procedure was performed in 13 patients suffering from panfacialfractures associated with a fracture of skull base or a displacednasal fracture, and in one patient with post-caustic burn scaraffecting most of the face including the nose and requiringa full thickness skin flap surrounding the mouth. Results: The technique was found easy and satisfactory for both the surgeonand the anaesthetist. It allowed uninterrupted surgical techniquesand a secure airway. In six of the 13 patients, the submandibulartracheal tube was left in place for up to 44 h in the intensivecare unit after the operation without complications or difficulties.Accidental dislodgement of the tube to the right main bronchusoccurred in two patients while carrying out the procedure; itwas rapidly detected and corrected. In another two patients,postoperative superficial infection occurred that respondedwell to local treatment. No other complications were encountered. Conclusions: Submandibular tracheal intubation is a simple and effectivetechnique for upper airway management in some maxillofacialsurgical patients when both oral and nasal tracheal intubationsare not convenient.     

Effect of buprenorphine on the cardiovascular response to tracheal intubation

The effects of buprenorphine on the haemodynamic responses to tracheal intubation were studied in a placebo-controlled double-blind trial in 40 patients who had elective surgery. In one group saline was administered intravenously 8 minutes before induction, whereas the others received buprenorphine 2.5 micrograms/kg intravenously. Anaesthesia was induced in both groups with thiopentone 4 mg/kg followed by suxamethonium 1.5 mg/kg after 90 seconds. In the buprenorphine group, the maximum increase in systolic and diastolic arterial blood pressures, heart rate and rate pressure product were significantly lower compared to the control group. It is concluded that buprenorphine is partially effective in attenuating the cardiovascular response to laryngoscopy and intubation, but does not obliterate it.     

Cardiovascular and arousal responses to laryngoscopy and tracheal intubation in patients with complete spinal cord injury

Background: We aimed to determine whether the autonomic and arousal responsesto laryngoscopy and tracheal intubation were altered in patientswith spinal cord injury (SCI). Methods: One hundred and sixteen patients with traumatic complete SCIwere grouped according to the time elapsed after the injury(<3 days and >9 months) and the level of injury (aboveT5 and below T5): acute high (AH, n=25), chronic high (CH, n=26),acute low (AL, n=20), and chronic low (CL, n=45). Twenty-fivepatients without SCI served as a control group. Bispectral index(BIS) response, systolic arterial pressure (SAP), heart rate(HR), and plasma concentrations of catecholamines and argininevasopressin were measured. Results: Both CH and CL groups showed a greater reduction in BIS valuesafter induction of anaesthesia with thiopental compared withcontrols (P<0.05). However, BIS values after intubation increasedsimilarly in all groups from the value measured just beforelaryngoscopy. SAP increased in the AL and CL and control groupsbut not in the AH and CH groups. HR increased significantlyin all groups; though to a lesser degree in the AH comparedwith the other groups. Plasma norepinephrine concentrationsincreased in all except the AH group, but vasopressin concentrationswere unchanged. Conclusions: The arousal response to laryngoscopy and tracheal intubationas measured by BIS is not altered in SCI, but cardiovascularand catecholamine responses may be changed depending on timeelapsed and the level of the injury. However, an identical doseof thiopental may reduce BIS value after intubation more profoundlyin patients with chronic SCI.     

依托咪酯乳剂诱导时雷米芬太尼抑制气管插管反应的效应室靶浓度

目的 测定依托咪酯乳剂诱导时雷米芬太尼抑制气管插管反应的效应室靶浓度(EC50和EC95).方法 选择23例ASAⅠ或Ⅱ级全麻择期手术患者靶控输注(TCI)雷米芬太尼,血浆浓度与效应室浓度达到平衡后静脉注射依托咪酯乳剂0.3 mg/kg,患者意识消失后静脉注射琥珀胆碱行气管插管.气管插管后2 min内最高的SBP和/或HR高出基础值15%为气管插管反应阳性.雷米芬太尼靶浓度按改良序贯法增加或减少0.5 ng/ml.用概率单位回归分析法计算出雷米芬太尼抑制气管插管反应的EC50、EC95及相应的95%可信区间(CI).结果 雷米芬太尼抑制气管插管反应的EC50为3.06 ng/ml,95%CI为2.56～3.47 ng/ml;相应的EC95为3.85 ng/ml,95%CI为3.45～6.64ng/ml.结论 复合依托咪酯0.3 mg/kg诱导时雷米芬太尼抑制气管插管反应的EC50和EC95分别为3.06 ng/ml和3.85 ng/ml.