Rapid oral anesthesia for awake intubation.

STUDY OBJECTIVE: To determine whether sodium benzonatate (Tessalon Perles) can provide rapid, effective topical oral anesthesia in preparation for awake intubations. DESIGN: Randomized, controlled, single-blind study. SETTING: Medical center anesthesia department. PATIENTS: Forty patients counseled for an awake intubation. INTERVENTIONS: The patients were randomized (random permutated block) to receive either benzonatate 200 mg topically for oropharyngeal anesthesia or bilateral superior laryngeal nerve blocks (total 8 ml of 1% lidocaine) in conjunction with 2 ml of 20% benzocaine orally. Both groups were administered 4 ml of 4% lidocaine translaryngeally. If nasal intubation was anticipated, the patients received 6 ml of 2% lidocaine jelly for nasal anesthesia. MEASUREMENTS AND MAIN RESULTS: The time to obtain oropharyngeal anesthesia was measured as the time from obtaining the benzonatate capsules from the bottle or palpation of the neck to locate the hyoid bone to the time when the patient exhibited an absent gag response to an oropharyngeal airway. After completion of airway preparation, the patient's response to intubation was evaluated by an anesthesiologist blinded to the method of preparation. Medications administered for sedation and analgesia were recorded. Noninvasive blood pressure, heart rate (HR), cardiac rhythm, and three-lead ST segments (I, II, V5) were recorded and evaluated for changes from baseline. Postoperatively, the patient was questioned for recall of the intubation. The time required to obtain loss of the gag response was shorter in the benzonatate group (55.1 +/- 5.7 seconds vs 339 +/- 22.4 seconds, p less than 0.005). The patient response to intubation was similar in both groups (90% no response, 10% minimal response). No abnormal cardiac rhythms or ST segment depression occurred, and mean arterial pressure and HR did not increase more than 20%. CONCLUSIONS: The results of this study indicate that benzonatate capsules provide rapid and reliable oropharyngeal anesthesia in preparation for awake intubation. In addition, if excellent airway anesthesia is provided, awake intubations can be accomplished with minimal patient response and discomfort.     

Usability of AirWay Scope for awake tracheal intubation in a burn patient with difficult airway

The AirWay Scope (AWS; PENTAX Corporation, Tokyo, Japan) is a newly developed rigid video laryngoscope with a built-in LCD monitor that provides accurate verification of tube passage through the vocal cords during tracheal intubation procedures. The blade is shaped to fit the oropharyngeal anatomy, which enables operators to achieve an optimal view for tracheal intubation without requiring alignment of the oral, pharyngeal, and laryngeal axes. We used an AWS for awake intubation in a 34-year-old male burn patient with a difficult airway under conscious sedation obtained with infusion of dexmedetomidine (DEX). Following topical anesthesia of the upper airway and preoxygenation, sedation was induced with 6 microg kg(-1) hr(-1) of DEX for 13 minutes and maintained at 0.5 microg kg(-1) hr(-1). Thereafter, insertion of the AWS gave a Cormack grade 1 glottic view, and endotracheal anesthesia was provided by use of a modified spray tube through the AWS blade without patient anxiety or discomfort. The trachea was intubated using the AWS without respiratory depression or other complications while the patient was sedated (Ramsay sedation scale class 4). We consider the AWS to be useful for awake tracheal intubation in patients with a difficult airway.     

Both local anesthetics and salbutamol pretreatment affect reflex bronchoconstriction in volunteers with asthma undergoing awake fiberoptic intubation

BACKGROUND: Awake tracheal intubation may evoke reflex bronchoconstriction in asthmatics. Whether this effect is altered by the choice of the local anesthetic used or by pretreatment with a beta2-adrenoceptor agonist is unknown. Therefore, we assessed the effect of awake fiberoptic intubation after lidocaine or dyclonine inhalation with or without pretreatment with salbutamol on lung function in asthmatic volunteers. METHODS: Bronchial hyperreactivity was verified by an inhalational histamine challenge. On four different days in a randomized, double blind fashion the volunteers (n = 10) inhaled either dyclonine or lidocaine with or without salbutamol pretreatment. FEV1 was measured at baseline, following salbutamol or saline inhalation, after lidocaine or dyclonine inhalation, while intubated, and after extubation. Lidocaine and dyclonine plasma concentrations were also measured. Statistics: Two-way ANOVA, post hoc tests with Bonferroni correction, results are presented as mean +/- SD. RESULTS: Neither lidocaine nor dyclonine inhalation changed FEV1 significantly from baseline compared with placebo inhalation (4.43 +/- 0.67 l vs. 4.29 +/- 0.72 l, and 4.53 +/- 0.63 l vs. 4.24 +/- 0.80 l, respectively). Salbutamol slightly but significantly increased FEV1 (4.45 +/- 0.76 l vs. 4.71 +/- 0.61 l, P = 0.0034, and 4.48 +/- 0.62 l vs. 4.71 +/- 0.61 l, P = 0.0121, respectively). Following awake intubation FEV1 significantly decreased under lidocaine topical anesthesia (4.29 +/- 0.72 l to 2.86 +/- 0.87 l) but decreased even more under dyclonine anesthesia (4.24 +/- 0.80 l to 2.20 +/- 0.67 l; P < 0.0001). While salbutamol pretreatment significantly attenuated the response to intubation, it did not eliminate the difference between the effects of lidocaine and dyclonine. Only minutes after extubation FEV1 was similar compared with baseline. CONCLUSION: In asthmatics, awake fiberoptic intubation evokes a more than 50% decrease in FEV1 following dyclonine inhalation. Using lidocaine for topical anesthesia the decrease in FEV1 is significantly mitigated (35%) and can be even further attenuated by salbutamol pretreatment. Therefore, combined treatment with lidocaine and salbutamol can be recommended for awake intubation while the use of dyclonine, despite its excellent and longer lasting topical anesthesia, may be contraindicated in patients with bronchial hyperreactivity.     

Anesthesia of the airway by aspiration of lidocaine

PURPOSE: Lidocaine instilled onto to the back of the tongue of a supine subject and aspirated has been reported to provide effective topical anesthesia of the airway. The purpose of this study was to observe endoscopically the fate of lidocaine so instilled and document the efficacy of anesthesia for awake fibreoptic intubation. METHODS: In Part I of the study, a fibreoptic bronchoscope was positioned in the pharynx of three volunteers lying supine and the route followed by tinted lidocaine solution instilled onto the back of the protruded tongue during mouth breathing was observed. In Part 2, the airway of 39 patients requiring awake fibreoptic intubation was anesthetized by having them gargle twice with 5 ml lidocaine 2%, followed by instillation of 0.2 ml-kg(-1) or 20 ml lidocaine 1.5% (whichever was less) onto the dorsum of their tongues as described above. The efficacy of anesthesia was scored by the patient reaction (coughing or gagging) to instrumentation in the pharynx, at the glottis, and in the trachea; to passage of the tracheal tube into the trachea; and to the presence of the tube in the trachea. RESULTS: Lidocaine instilled on to the back of the tongue was swallowed initially but ultimately pooled in the pharynx and was aspirated. In all patients the trachea was intubated without requiring supplemental lidocaine, and all but one patient tolerated the tracheal tube in situ. CONCLUSION: A combination of lidocaine gargles and lidocaine instilled on to the back of the tongue and aspirated provides effective anesthesia of the pharynx, larynx, and trachea for awake fibreoptic intubation.     

利多卡因对气管平滑肌舒张作用的研究

利多卡因是临床上常用的局部麻醉药和抗室性心律失常药物;除此之外,利多卡因还具有较强的扩张气道、抑制气道炎症、降低气道高反应性的作用。此方面的研究最早可追溯到上世纪60年代,利多卡因在围术期预防和处理支气管痉挛中所占的地位已得到充分肯定,现将近10余年来利多卡因对气道平滑肌影响的主要研究成果综述如下。     

Propofol is superior to thiopental for intubation without muscle relaxants

PURPOSE: To compare intubating conditions and cardiovascular changes following induction of anesthesia and tracheal intubation in patients receiving either lidocaine-remifentanil-propofol or lidocaine-remifentanil-thiopental prior to induction. METHODS: In a randomized, double-blind study 76 healthy adult patients were assigned to one of two groups: lidocaine 1.5 mg.kg(-1), remifentanil 2 mug.kg(-1) and propofol 2 mg.kg(-1) (Group P) or lidocaine 1.5 mg.kg(-1), remifentanil 2 mug.kg(-1) and thiopental 5 mg.kg(-1) (Group T). Ninety seconds after the administration of the hypnotic agent, laryngoscopy and tracheal intubation were attempted. Intubating conditions were assessed as excellent, good or poor on the basis of ease of ventilation, jaw relaxation, position of the vocal cords, and patient's response to intubation and slow inflation of the tracheal cuff. The mean arterial pressure (MAP) and heart rate (HR) were measured 45 sec after hypnotic agent administration, immediately after tracheal intubation, two and five minutes after intubation. RESULTS: Excellent intubating conditions were obtained in 84% of Group P patients and 50% of Group T patients (P < 0.05). The percentage decrease from baseline MAP was significantly higher in Group P than in Group T postinduction (27.4% +/- 11.6 vs 21.8% +/- 10.0) and immediately postintubation (19.0% +/- 16.7 vs 11.2% +/- 14.9). The percentage change from baseline HR was significantly higher in Group P than in Group T postinduction (13.8% +/- 9.7 vs 0.5% +/- 12.4), immediately postintubation (8.7% +/- 13.7 vs 2.1% +/- 13.1), and two minutes postintubation (7.04% +/- 14.3 vs 3.5% +/- 14.3). CONCLUSION: Lidocaine-remifentanil-propofol is superior to lidocaine-remifentanil-thiopental for tracheal intubation without muscle relaxants. However, it induces more hypotension and bradycardia.     

雾化吸入利多卡因用于颈髓损伤患者纤维支气管镜引导气管插管时表面麻醉的效果

目的 评价雾化吸入利多卡因用于颈髓损伤高位截瘫患者纤维支气管镜(FOB)引导气管插管时表面麻醉的效果.方法 颈椎骨折并发高位截瘫患者64例,随机分为2组(n=32),雾化吸入组:雾化吸入2%利多卡因;喷雾联合环甲膜穿刺组:咽喉部喷雾联合环甲膜穿刺注射2%利多卡因,随后于FOB引导气管插管前15 min,两组均静脉注射咪达唑仑0.01 mg/kg、芬太尼1 μg/kg.FOB引导气管插管期间,评价气管插管条件,监测MAP、HR、ECG及SpO2.结果 与喷雾联合环甲膜穿刺组相比,雾化吸入组气管插管条件满意率和FOB引导气管插管成功率明显提高,心律失常及不良记忆发生率明显降低(P＜0.05).结论 颈髓损伤高位截瘫患者雾化吸入2%利多卡因表面麻醉,有助于改善FOB引导气管插管的条件,且降低不良反应的发生.     

Effects of alfentanil and lidocaine on the hemodynamic responses to laryngoscopy and tracheal intubation

This study was undertaken to determine whether lidocaine and/or alfentanil can effectively abolish or attenuate the increase in mean arterial pressure (MAP), heart rate (HR), and rate pressure product (RPP) associated with rapid sequence induction of anesthesia. Sixty patients were randomly divided into four groups. Group 1 received saline 10 ml, group 2 received lidocaine 2 mg/kg, group 3 received alfentanil 15 micrograms/kg, and group 4 received alfentanil 30 micrograms/kg. All patients were induced with sodium thiopental 4 mg/kg and succinylcholine 1.5 mg/kg to facilitate tracheal intubation. The study drug was given after sodium thiopental was administered, and the investigator was blinded to it. Blood pressure (BP) and HR were recorded at the following times: before induction; after induction but before laryngoscopy and intubation; and 1, 3, and 5 minutes after intubation. Alfentanil 15 and 30 micrograms/kg given in rapid sequence fashion with thiopental and succinylcholine effectively blunted the hemodynamic responses to laryngoscopy and tracheal intubation. Lidocaine 2 mg/kg and saline were found to be ineffective in blunting these same responses.     

不同的氧气流量对雾化吸入利多卡因进行表面麻醉效果的影响

目的探讨不同的氧气流量对雾化吸入2%利多卡因进行气道表面麻醉效果的影响。方法选择需行清醒气管插管的困难气道患者75例,按随机数字表法分为A、B、C三组(n=25),所有患者都通过氧气驱动雾化吸入2%利多卡因10 m L的方法进行气道黏膜表面麻醉,但A、B、C三组患者所用的氧气流量分别为3 L/min、6 L/min、9 L/min,雾化吸入结束后使用纤支镜引导进行气管插管。评估记录插管条件和导管耐受性;记录气管插管首次成功率、总成功率、插管时间;记录不良心血管反应和并发症发生情况。结果与A组和C组比较,B组的插管条件、导管耐受性更好,气管插管首次成功率更高,插管时间更短(Ρ0.05);A、C两组间比较,无明显差异。结论在清醒气管插管过程中定量雾化吸入2%利多卡因进行气道粘膜表面麻醉时,氧气流量为6 L/min的效果更好。     

Awake tracheal intubation through the intubating laryngeal mask airway in a patient with halo traction

PURPOSE: To report a case of awake tracheal intubation through the intubating laryngeal mask airway (ILMA) in a patient with halo traction. Clinical features: A 16-yr-old, 40 kg, boy with atlanto-occipital instability and halo traction was scheduled for surgery under general anesthesia. The head of the patient was fixed in a position of flexion and extension was impossible. Cranial magnetic resonance imaging revealed that pharyngeal and laryngeal axes were aligned, but that the oral axis was in an extreme divergent plane. The tongue and oropharynx were anesthetized with 10% lidocaine spray and bilateral superior laryngeal nerve blockade was performed. Under sedation, awake orotracheal intubation via ILMA was successful. Fibreoptic bronchoscopy has been recommended for awake tracheal intubation in such patients. Other techniques, such as use of the Bullard laryngoscope have been described also but awake tracheal intubation through the ILMA in patients with a halo device in situ has seldom been reported in the medical literature. CONCLUSION: Airway management of patients with cervical spine instability includes adequate preoperative evaluation of the airway and choosing the appropriate intubation technique. We suggest that the ILMA may be an adequate alternative for awake tracheal intubation in patients with an unstable cervical spine and cervical immobilization with a halo device.     

支撑喉镜下CO2激光治疗小儿喉乳头状瘤的麻醉管理

本院2003年5月-2007年5月支撑喉镜下CO2激光治疗喉乳头状瘤患儿28例,男性19例,女性9例,年龄lO个月～3.5岁,体重8～15 kg,无喉阻塞患儿17例,喉阻塞Ⅰ度患儿7例,喉阻塞Ⅱ度或Ⅲ度息儿4例.术前对全身和喉部病变情况进行评估,根据不同喉阻塞程度选用不同的麻醉方法,纠正术前呼吸系统感染、脱水、电解质紊乱等合并症后行手术.麻醉诱导:无喉阻塞患儿肌肉注射氯胺酮5mg/kg,入睡后静脉注射咪达唑仑0.1 mg/kg、氯胺酮1～2 mg/kg或芬太尼2μ g/kg和琥珀胆碱1.5 mg/kg后气管插管;喉阻塞Ⅰ度患儿肌肉注射氯胺酮5 mg/kg,保留自主呼吸充分给氧,l%地卡因充分表面麻醉后气管插管;喉阻塞Ⅱ度或Ⅲ度患儿1%地卡因充分表面麻醉后气管插管;所有患儿均在喉镜直视下插入较正常小1号的气管导管,行辅助通气或机械通气.麻醉维持:间断静脉注射维库溴铵0.05-0.1 mg/kg和氯胺酮1～2 mg/kg,静脉输注异丙酚3～5 mg·kg-1·h-1,维持HR 110～150次/min,MAP 70～90 mm Hg.术毕时均静脉注射地塞米松0.2-0.3 mg/kg.待患儿清醒、吸空气维持SpO2≥96%时拔除气管导管.除喉阻塞Ⅰ度患儿中1例麻醉诱导时行紧急气管切开外,其余患儿麻醉诱导平稳,麻醉效果满意,血液动力学稳定,术后自主呼吸恢复平稳,均顺利完成手术.激光治疗中未见气管导管损伤及燃烧等情况发生,术中及术后未见窒息、喉痉挛及支气管痉挛等并发症发生.     

Rapid tracheal intubation with vecuronium: the priming principle

Following the administration of a single 0.1 mg/kg dose of vecuronium bromide, satisfactory conditions for tracheal intubation developed in 156 +/- 12 s (mean +/- SEM), and the clinical duration of the initial dose was 36 +/- 2 min. When the initial dose of vecuronium was administered in two increments, a 0.015 mg/kg "priming" dose, followed 6 min later by a 0.050 mg/kg "intubating" dose, intubation time decreased to 61 +/- 3 s and clinical duration to 21 +/- 1 min. The priming dose that had no unpleasant effect on premedicated, awake patients could be administered 3-4 min before, and the intubating dose 2 to 3 min after induction of anesthesia. With the described technique, comparable intubating conditions could be obtained just as rapidly with vecuronium as with succinylcholine chloride, without subjecting the patients to the side effects of and the complications occasionally encountered with succinylcholine. An added advantage of the use of a priming dose is that it will reveal undiagnosed, pathologic, or idiopathic increase of sensitivity to nondepolarizing muscle relaxants.     

Myocardial metabolism as affected by propofol in geriatric patients. A comparison with etomidate

This study was designed to compare the effects of propofol and etomidate on myocardial metabolism in elderly patients without clinical manifestations of heart failure or coronary artery disease. Twenty geriatric patients (age 65-82 years) scheduled to undergo elective major upper-abdominal surgery were studied and randomly allocated to two equal groups (propofol and etomidate). All patients were premedicated with piritramide, 7.5 mg, and promethazine, 25 mg, intramuscularly 1 h before arrival in the anesthesia room. Ten patients received propofol (1.5 mg/kg) for induction of anesthesia, followed by 10-min infusion of an induction dose; thereafter, anesthesia was maintained with a continuous infusion of 0.1 mg/kg per min. Ten patients received etomidate, 18 mg, for induction, followed by 2.4 mg/min for maintenance. Vecuronium was used for neuromuscular blockade. Cardiovascular dynamics were recorded while the patients were awake, 1-2 min after induction during apnoea, and 1, 5 and 30 min after tracheal intubation without surgical stimulation. Coronary blood flow (argon wash-in technique with sampling of blood from the coronary sinus), myocardial oxygen consumption and myocardial uptake of glucose, free fatty acids and lactate were determined in the awake state and 5 and 30 min after intubation. Arterial plasma concentrations of propofol (high-pressure liquid chromatography with fluorescence detection) and etomidate (gas chromatography) were measured every 5 min throughout the investigation period, which lasted 45 min. Overall mean plasma concentrations of propofol were 3.69 +/- 0.16 micrograms/ml and of etomidate 1.1 +/- 0.16 microgram/ml.(ABSTRACT TRUNCATED AT 250 WORDS)     

右美托咪啶抑制患者清醒纤维支气管镜插管反应的临床剂量探讨

【摘要】 目的 测定右美托咪啶抑制患者清醒纤维支气管镜插管反应的半数有效剂量(ED50)。方法 选择全身麻醉、预计存在困难气道的20例患者,ASA分级Ⅰ或Ⅱ级,年龄38~65岁,体重45~70 kg;右美托咪啶持续静脉输注10 min后,用1%丁卡因对舌根部、咽喉部及声门上进行表面麻醉,2%利多卡因2 mL经环甲膜穿刺行气管表面麻醉,然后行经鼻纤维支气管镜插管。右美托咪啶的给药剂量按序贯法确定,相邻剂量之间的比率为1.2。采用改良Dixon序贯法计算右美托咪啶抑制清醒纤维支气管镜插管反应的ED50及其95%可信区间,并采用logistic回归模型进行概率单位转换分析ED50及其95%可信区间。结果 右美托咪啶抑制患者清醒纤维支气管镜插管反应的ED50为0.74 μg/kg,其95%可信区间为0.68 μg/kg~0.82 μg/kg。结论 静脉输注右美托咪啶0.74 μg/kg,可以为50%的已行气道表面麻醉的患者在清醒纤维支气管镜插管过程中提供满意的气管插管条件,且无气管插管反应发生。     

Use of the intubating laryngeal mask airway to facilitate awake orotracheal intubation in patients with cervical spine disorders.

Airway management in patients with unstable cervical spines remains a challenge for anesthesia providers. Because neurologic evaluations may be required following tracheal intubation and positioning for the surgical procedure, an awake intubation technique is desirable in this patient population. In this report, we describe the use of an intubating laryngeal mask airway (ILMA) to facilitate awake tracheal intubation in two patients with cervical spine disorders. After topical local analgesia, the ILMA was inserted easily, and a tracheal tube was passed through the glottic opening without complications. Thus, the ILMA may be an acceptable alternative to the fiberoptic bronchoscope for awake tracheal intubation.     

Which drug prevents tachycardia and hypertension associated with tracheal intubation: lidocaine, fentanyl, or esmolol?

Eighty patients, ASA physical status II-IV, scheduled for noncardiac surgery, were randomly assigned in a double-blind, placebo-controlled manner to receive a preintubation dose of either placebo, 200 mg lidocaine, 200 micrograms fentanyl, or 150 mg esmolol. Induction of anesthesia was accomplished with 4-6 mg/kg thiopental IV followed immediately by the study drug; 1-1.5 mg/kg succinylcholine was given at minute 1. Laryngoscopy and intubation were performed at minute 2 with anesthesia thereafter maintained with 1 MAC (+/- 10%) isoflurane in 60% nitrous oxide in oxygen at a 5 L/min flow for 10 min. Heart rate was recorded every 15 s and blood pressure every minute from induction until 10 min after intubation. Maximum percent increases in heart rate (mean +/- SE) during and after intubation were similar in the placebo (44% +/- 6%), lidocaine (51% +/- 10%), and fentanyl (37% +/- 5%) groups, but lower in the esmolol (18% +/- 5%) group (P less than 0.05). Maximum systolic blood pressure percent increases were lower in the lidocaine (20% +/- 6%), fentanyl (12% +/- 3%), and esmolol (19% +/- 4%) groups than in the placebo (36% +/- 5%) group (P less than 0.05), but not different from each other (P greater than 0.05). Only esmolol provided consistent and reliable protection against increases in both heart rate and systolic blood pressure accompanying laryngoscopy and intubation.     

Differences in Cardiovascular Response to Airway Stimulation at Different Sites and Blockade of the Responses by Lidocaine

Background: Mechanical stimulation of the airways elicits abrupt cardiovascular responses (CVR) in anesthetized humans. We examined a potential difference in such responses by comparing changes in heart rate (HR) and arterial blood pressure (AP) responses to mechanical stimulation of three different parts of the airways, as well as the effects of localized airway anesthesia with lidocaine on these responses.

Methods: After induction of general anesthesia, the larynx under laryngeal mask insertion (L, n = 20), the trachea-carina under tracheal intubation (T, n = 20), or the bronchus under bronchial intubation (B, N = 20) of each patient was mechanically stimulated in a similar manner. The same stimulation was repeated in 15 patients in each group after 5 ml of 4% lidocaine had been sprayed onto the part of the airway being stimulated. To test the systemic effect, intravenous lidocaine 1 mg/kg was given to five patients in each group, followed by the same airway stimulation. Consequent changes in HR and AP were continuously recorded and analyzed.

Results: Significant increases in HR and AP in response to airway tactile stimulation differed in magnitude according to the stimulated sites (L > T >= B). These responses were completely blocked by topical application of lidocaine and partially blocked by intravenous lidocaine.     

Awake intubation using lightwand technique under conscious sedation with remifentanil

We experienced two cases of difficult airway due to deformities in the oral cavities. The first patient was a 62-year-old woman with a large benign soft palate tumor and the second was a 64-year-old woman with macroglossia secondary to acromegaly. Both patients were evaluated difficult to ventilate via face mask and presenting serious risks for tracheal intubation under general anesthesia. The tracheal intubation was planned using the lightwand (Trachilight) under conscious sedation with continuous administration of remifentanil. Remifentanil (0.1-0.25 microg x kg(-1) x min(-1)) maintained the patients' spontaneous ventilation and increased their tolerance to the pain and discomfort caused by insertion of the lightwand. In both patients, remifentanil mildly suppressed the coughing reflex as well as the autonomic responses to stimuli to the airway. Tracheal intubation was managed successfully in both cases and the operations were completed under general anesthesia. Although the patients were aware of being intubated, they could not recall the procedures postoperatively. The awake intubation technique using the lightwand under conscious sedation with remifentanil can be safely applied to a patient with difficult airway.     

Awake intubation of the adult trachea using the Bullard laryngo-scope

Awake intubation using the Bullard laryngoscope can be comfortably and easily performed in the adult. Five cases are presented in which tracheal intubation was performed under topical anaesthesia with light intravenous sedation. In each case, topical anaesthesia was performed by insertion of a Guedel oral airway, with lidocaine ointment applied to the inferior and posterior surfaces. In one case, Bullard intubation was successful where direct laryngoscopy and multiple attempts at bronchoscopic intubation by three different operators had failed. We conclude that the Bullard laryngoscope can be easily used in awake patients and may be a useful alternative where other methods for awake intubation have failed.     

Inhaled albuterol, but not intravenous lidocaine, protects against intubation-induced bronchoconstriction in asthma

BACKGROUND: The ability of intravenous lidocaine to prevent intubation-induced bronchospasm is unclear. The authors performed a prospective, randomized, double-blind, placebo-controlled trial to test the ability of intravenous lidocaine and inhaled albuterol to attenuate airway reactivity after tracheal intubation in asthmatic patients undergoing general anesthesia. METHODS: Sixty patients were randomized to receive either 1.5 mg/kg intravenous lidocaine or saline, 3 min before tracheal intubation. An additional 50 patients were randomized to receive 4 puffs of inhaled albuterol or placebo 15-20 min before tracheal intubation. Anesthesia was induced with propofol. Immediately after intubation and at 5-min intervals, transpulmonary pressure and airflow were recorded, and lower pulmonary resistance (RL) was calculated. Isoflurane was administered after the initial two measurements to assess reversibility of bronchoconstriction. A bronchoconstrictor response to intubation was defined as RL greater than or equal to 5 cm H2O. l-1. s-1 in the first two measurements after intubation and RL subsequently decreasing by 50% or more after isoflurane. RESULTS: The lidocaine and placebo groups were not different in the peak RL before administration of isoflurane (8.2 cm H2O. l-1. s-1 vs. 7.6 cm H2O. l-1. s-1) or frequency of airway response to intubation (lidocaine 6 of 30 vs. placebo 5 of 27). In contrast, the albuterol group had lower peak RL (5.3 cm H2O. l-1. s-1 vs. 8.9 cm H2O. l-1. s-1; P < 0.05) and a lower frequency of airway response (1 of 25 vs. 8 of 23; P < 0.05) than the placebo group. CONCLUSIONS: Inhaled albuterol blunted airway response to tracheal intubation in asthmatic patients, whereas intravenous lidocaine did not.