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.     

艾司洛尔与表面麻醉抑制插管反应时心率变异性的变化

目的比较观察全麻病人气管插管前静脉给予艾司洛尔或用表面麻醉抑制插管反应 时心率变异性(HRV)的变化。方法120例病人随机分为三组,每组40例,Ⅰ组为艾司洛尔组,Ⅱ组为单纯喉气管表面麻醉(LTA)组,Ⅲ组为口咽表面喷雾加LTA组。静注芬太尼2μg·kg-1,异丙酚2mg·kg-1,维库溴铵0．1mg·kg-1诱导插管。Ⅰ组病人插管前2min,静注艾司洛尔2mg·kg-1;Ⅱ组病人用喉镜暴露声门,用1％地卡因2．5ml行会厌、声门及气管内的表面麻醉2min后再行插管;Ⅲ组病人于麻醉前清醒时,用1％地卡因约0．5ml作舌背、软腭、咽及喉部喷雾,其余操作均与Ⅱ组相同。结果除Ⅰ组病人在插管即刻和插管后1min心率明显低于Ⅱ、Ⅲ组外(P<0．05),其它两组病人在插管前后血压、心率均无明显变化。HRV和LF在插管前后只有Ⅲ组保持不变,而Ⅰ、Ⅱ组病人在插管即刻、插管后1min均显著高于Ⅲ组(P<0．01)。Ⅲ组病人的LF／HF在插管即刻及插管后1min出现明显降低(P<0．05),与Ⅰ、Ⅱ组相比有显著性差异。结论插管前静脉注射艾司洛尔不能抑制应激反应的产生;表面麻醉能从根本上抑制应激反应的发生,但在插入喉镜前仍需完善的口咽喉部局麻作保证。     

The effect of diltiazem on the cardiovascular response to tracheal intubation

The efficacy of diltiazem in the attenuation of the cardiovascular response to laryngoscopy and tracheal intubation was studied in patients who received 0.2 or 0.3 mg/kg diltiazem 60 seconds before the start of laryngoscopy. These data were compared with a control group who received saline. Each group consisted of 10 patients who had elective surgery. Patients who received saline showed a significant increase in mean arterial pressure and rate pressure product associated with tracheal intubation. These increases after tracheal intubation were reduced in diltiazem-treated patients compared with those of the control group (p less than 0.05). The data suggest that a bolus injection of diltiazem is a simple, practical and effective method to attenuate the hypertensive response to laryngoscopy and tracheal intubation.     

Timing of high-risk vascular surgery following coronary artery bypass surgery: a 10-year experience from an academic medical centre

Major non-cardiac surgery within 40 days of coronary angioplasty with stenting has high cardiac complication rates. We have performed a case-control study to determine whether the risk of vascular surgery might have increased in recent survivors of coronary artery bypass surgery (CABG). Using our vascular database from 1990 to 1999, we matched the cases who had vascular surgery within a month of CABG with controls by pre-operative comorbidities of diabetes mellitus, history of myocardial infarction (MI), history of congestive heart failure (CHF), and chronic renal insufficiency and compared the incidence of peri-operative MI, CHF, death, and other complications. Compared to case-matched controls, patients who underwent vascular surgery within a month of CABG suffered significantly greater mortality (20.6% vs. 3.9%, p < 0.005). The incidence of non-fatal cardiac complications was not significantly different between the groups. We conclude that the risk of mortality may be significantly greater in patients undergoing major vascular surgery within a month of CABG.     

Effect of cricoid pressure on the ease of fibrescope-aided tracheal intubation

We studied the reasons for difficulty with tracheal intubation over a fibrescope, and whether cricoid pressure facilitated intubation, in 50 patients. After induction of anaesthesia and neuromuscular blockade in 10 patients (phase 1), we attempted to clarify the reasons for difficulty in advancing a tracheal tube over an orally-inserted fibrescope, by observing through another fibrescope that was inserted nasally into the pharynx. In the next 40 patients (phase 2), we studied the effect of cricoid pressure on the success rate of tracheal intubation over the fibrescope. After a fibrescope (with a tracheal tube over it) had been inserted orally into the trachea, patients were randomly allocated to receive either criocoid pressure or sham pressure, and the success rate of intubation within 60 s was assessed. In phase 1, the tube was advanced into the trachea without difficulty in three of 10 patients. In the remaining seven patients, the tube impacted on the epiglottis in one patient and on the arytenoid cartilage in another two patients, and the tube migrated into the hypopharynx in the remaining four patients. In phase 2, tracheal intubation was successful within 60 s in seven of 21 patients (33%) without cricoid pressure, compared with 12 of 19 patients (63%) when cricoid pressure was applied (95% CI for difference 2-59%; p = 0.04). We conclude that cricoid pressure facilitates fibrescope-aided tracheal intubation.     

Survey of use of end-tidal carbon dioxide for confirming tracheal tube placement in intensive care units in the UK

The use of end-tidal carbon dioxide monitoring to confirm the correct placement of a tracheal tube immediately after intubation is mandatory in the operating theatre. Tracheal intubation in critically ill patients can be challenging. Quick and accurate confirmation of tracheal tube placement is essential to minimise complications. This survey explored the use of end-tidal carbon dioxide monitoring to confirm tracheal tube placement in intensive care units in the UK. Questionnaires were sent to either the lead clinician or clinical director of randomly selected general adult intensive care units. One hundred and twenty-seven replies were received from the 215 questionnaires sent (response rate 59%). Twenty per cent of the units did not have an end-tidal carbon dioxide monitor, 20% had one end-tidal carbon dioxide monitor per bed and 60% had one end-tidal carbon dioxide monitor between several beds. Only 50% of the units having an end-tidal carbon dioxide monitor use it to confirm correct tracheal tube placement. Of these 50%, only about a third use it for every intubation. Seventy-two per cent of respondents felt that end-tidal carbon dioxide is well suited to confirm correct placement of tracheal tube in critically ill patients, but 50% did not think that confirmation using end-tidal carbon dioxide should be mandatory for intubations outside the operating theatre. Half of the units not having end-tidal a carbon dioxide monitor cited lack of resources as a reason. In summary, although four in every five intensive care units surveyed have end-tidal carbon dioxide monitors, only a small proportion use them to confirm correct placement of tracheal tube after intubation.     

艾司洛尔对老年冠心病患者气管插管QTc间期的影响

目的 评价艾司洛尔在麻醉诱导气管插管时对老年冠心病患者QTc间期的影响.方法 50例ASA Ⅱ级,年龄60～75岁择期全麻手术患者随机分为艾司洛尔组(E组)与对照组(C组).E组麻醉诱导前单次静脉缓慢注射艾司洛尔0.3 mg/kg后100 μg·kg-1·min-1持续输注至气管插管后4 mim;C组给予等容量生理盐水.记录给予艾司洛尔前(T0)、单次给予艾司洛尔或生理盐水后2 min(T1)、芬太尼与丙泊酚诱导后1 min(T2)、维库溴铵后3 min(插管前,T3)及插管后30 s(T4)、2 min(T5)与4 min(T6)QTc、MAP及HR变化.结果 T4～T6时QTc间期C组均长于T0时(P＜0.05),且C组明显长于E组(P＜0.01),其中QTc＞440 ms者C组显著多于E组(P＜0.05).结论 麻醉诱导气管插管期间老年冠心病患者QTc间期延长,而艾司洛尔可缩短与气管插管有关的QTc间期延长.     

Assessing the position of the tracheal tube The reliability of different methods

Various methods have been developed to confirm proper intubation of the trachea. This blind, randomised study evaluates some of these quantitatively and qualitatively. Forty patients had both their trachea and oesophagus intubated. A procedure that included auscultation of the upper abdomen and lungs was 100% reliable independent of which tube was ventilated. Auscultation of the lungs resulted in a wrong conclusion in 15% (6-30, 95% confidence limits) of the cases when the oesophagus was ventilated: the sounds were misinterpretated as normal breath sounds. Suction on the tubes with a 60-ml syringe was also a reliable test. Other methods assessed were observation for condensation of water vapor, and abnormal movements of the upper abdomen; these were unreliable.     

Use of the flexible intubating fibrescope for tracheal re-intubation in a patient with difficult extubation

Difficulty in tracheal extubation was experienced in a patient following major maxillofacial surgery for reconstruction of the maxilla using bone grafts and a microvascular free flap. With the aid of an intubating flexible fibrescope, the cause of the difficulty was identified as a stitch accidentally transfixed through the tracheal tube. Tracheal re-intubation was required to facilitate surgical exploration to remove the stitch and the proximal end of the tube. The tip of an Olympus LF-2 intubating fibrescope was successfully negotiated in the trachea alongside the original tube with its cuff deflated. This allowed safe and speedy railroading of a new tube immediately after the distal end of the original tube was removed.     

The effect of a pre-operative infusion of Ringer's solution on splanchnic perfusion in patients undergoing coronary artery bypass grafting

Surgical patients develop a fluid deficit during pre-operative starvation. This study examines the effects of pre-operative fluid administration on haemodynamic variables, oxygenation and splanchnic perfusion in patients undergoing elective coronary artery bypass grafting. Forty-eight patients were randomised to receive either a pre-operative crystalloid infusion (crystalloid group, n = 24) or no infusion (control group, n = 24). Patients in the crystalloid group received a continuous infusion of Ringer's solution at 1.5 ml.kg(-1).h(-1) from 22:00 h until induction of anaesthesia the next morning. Immediately before induction of anaesthesia, all patients were given a colloid infusion to increase pulmonary capillary wedge pressure and central venous pressure to similar levels in both groups. Haemodynamic and oxygenation parameters were measured using invasive cardiovascular monitoring, and splanchnic perfusion was assessed by indocyanine green clearance. Patients in the crystalloid group received a mean (SD) of 1008 (140) ml of Ringer's solution overnight. Patients in the crystalloid group had a higher splanchnic blood flow than the control group before induction of anaesthesia [mean (SD) = 1782 (573) ml.min(-1) vs. 1391 (333) ml.min(-1), p < 0.05]. There were no significant differences in systemic haemodynamic data and global oxygenation parameters between the two groups. Pre-operative infusion of crystalloid appears to result in an improvement in pre-operative splanchnic perfusion.     

Assessment of the efficacy of esmolol on the haemodynamic changes induced by laryngoscopy and tracheal intubation: a meta-analysis

BACKGROUND: Adrenergic stress response induced by laryngoscopy and tracheal intubation (LTI) appears to be attenuated by esmolol, but its potential clinical benefits have not been fully weighed against possible adverse effects. METHODS: A systematic search up to May 2000 was performed using MEDLINE, EMBASE, LILACS, Cochrane library, manual searching and bibliographies in all languages. All randomised comparisons of esmolol with placebo on the haemodynamic changes elicited by LTI were obtained. Trials were included in the present meta-analysis if they recorded heart rate (HR), systolic pressure (SBP), mean arterial pressure (MAP) or diastolic pressure (DBP) at three different stages: pre-induction, immediately prior to intubation, and in the post-intubation period. Weighted mean differences (WMD) and 95% confidence intervals (CI) of the changes in the haemodynamic variables between treatment and placebo groups were calculated. RESULTS: Of 72 publications identified, 38 randomised controlled trials containing a total of 2009 patients were finally included. Eleven different regimens and doses of esmolol demonstrated effectiveness in the attenuation of HR and BP after LTI in a dose-dependent manner. The most effective regimen was a loading dose of 500 microg x kg(-1) x min(-1) over 4 min followed by continuous infusion dose of 200-300 microg x kg(-1) x min(-1) [WMD: 20.2 bpm (95% CI: 15.6 to 24.7)]. High bolus dose (200 mg) of esmolol produced a considerable decrease in DBP [WMD 10.1 mmHg (95% CI: 7.3 to 12.8)]. CONCLUSION: Esmolol is effective, in a dose-dependent manner, in the attenuation of the adrenergic response to LTI. To minimise its adverse effects it should be administered, when considered clinically appropriate, as a continuous infusion regimen.     

The effect of propofol infusion on minimum alveolar concentration of sevoflurane for smooth tracheal intubation

Purpose. This study was conducted to determine the effect of propofol infusion on the minimum alveolar concentration necessary for smooth tracheal intubation (MACEI) of sevoflurane. Methods. Sixty-nine patients, American Society of Anesthesiologists (ASA) status I, aged 30–49 years, were randomly assigned to one of three groups according to the agents used for tracheal intubation (n = 23 for each group): the SP group, in whom the intubation was attempted under sevoflurane plus propofol infusion; the S group, tracheal intubation under sevoflurane alone; and the P group, tracheal intubation under propofol infusion alone. Anesthesia was induced with propofol 2.5 mg·kg⁻¹ i.v. bolus. Prior to the tracheal intubation attempt, propofol infusion, 10 mg·kg⁻¹·h⁻¹, was given for 15 min in the SP and P groups, and sevoflurane equilibration was established in the SP and S groups. All tracheal intubation attempts were made 15 min after anesthetic induction. The end-tidal sevoflurane concentration at which tracheal intubation was attempted was predetermined by the up-and-down method (with 0.5% as a step size). MACEI was determined using a logistic regression test. Results. The MACEI of sevoflurane was 1.73% in the SP group, and 2.99% in the S group. Laryngoscopy was not possible in the P group patients. Conclusion. Propofol infusion reduced sevoflurane MACEI. This finding suggests that propofol would be an excellent adjuvant to use with sevoflurane for tracheal intubation. Received: October 25, 2000 / Accepted: July 18, 2001     

A comparison of the intubating laryngeal mask tracheal tube with a standard tracheal tube for fibreoptic intubation

We conducted a prospective randomised study to compare the intubating laryngeal mask tracheal tube with a standard tube, for ease of tracheal intubation over a fibrescope. Thirty-six patients were investigated, using a sequential analysis technique. Ease of intubation was improved when the intubating laryngeal mask tracheal tube was used compared with the standard tube (p = 0.0009). Median (interquartile range [range]) intubation times (time from the tube's tip being level with the patient's teeth to successful placement) were 1.5 (1-2.3 [1-3]) s when the intubating laryngeal mask tracheal tube was used and 5 (3-7.3 [3-13]) s when the standard tube was used (p < 0.0001).     

应用艾司洛尔和二硝酸异山梨酯对气管内插管拔管时的心血管反应的影响

目的观察艾司洛尔和硝酸异山梨酯对全身麻醉患者苏醒后气管内导管撤除期间心血管反应的防治效果。方法ASA Ⅰ-Ⅱ级,全身麻醉下手术患者80人,随机分为4组,分别于气管导管撤除前给予生理盐水5ml（Ⅰ组,n=20）,硝酸异由梨酯20μg／kg（Ⅱ组,n=20）,艾司洛尔1mg／kg（Ⅲ组,n=20）以及艾司洛尔lmg／kg＋硝酸异山梨酯20μg／kg（Ⅳ组,n=20）。记录患者麻醉前和围拔管期心率（HR）、平均动脉压（MAP）和收缩压．心率乘积（RPP）,随访患者相关并发症。结果与Ⅰ组相比较,围拔管期Ⅱ、Ⅲ组患者HR、MAP和RPP均明显降低（P〈0．05）,Ⅳ组患者MAP低于Ⅲ组,更趋于平稳（P〈0．05）。所有患者均未出现低血压和心肌缺血等并发症。结论全身麻醉气管内导管撤除前适量使用艾司洛尔可以在一定程度上缓解患者心血管反应,合并使用硝酸异山梨酯效果更佳。     

The lack of benefit of tracheal extubation in the operating room after coronary artery bypass surgery

Although early tracheal extubation in cardiac anesthesia is safe and cost beneficial, questions still remain regarding how early after cardiac surgery patients should be tracheally extubated (TE). Our objective was to determine the effects on resource use if patients scheduled for coronary artery bypass grafting have TE in the operating room (OR). We studied 100 consecutive patients undergoing elective coronary artery bypass grafting, requiring extracorporeal circulation, and those eligible for a fast-track pathway. At the end of the procedure, the patients were evaluated for TE in the OR if they were hemodynamically stable, were without significant bleeding, and fulfilled clinical and blood gas analysis variables. Patients who did not meet the requirements had TE in the intensive care unit (ICU). Fifty patients had TE in the OR and 50 patients in the ICU. Time in the OR after skin closure, ICU length of stay, and postoperative length of stay were similar between the groups. Four patients (8%) in the OR group were tracheally reintubated secondary to respiratory depression (P = 0.11). Three patients (6%) in the OR group had postoperative myocardial infarction, and one postoperative myocardial infarction (2%) occurred in the ICU group (P = 0.61). All four patients recovered satisfactorily. The incidences of other complications were similar between groups.