Nong He

Spray-as-you-go airway topical anesthesia in patients with a difficult airway: a randomized, double-blind comparison of 2% and 4% lidocaine.

BACKGROUND: We designed this randomized, double-blind clinical study to compare the safety and efficacy of 2% and 4% lidocaine during airway topical anesthesia with a spray-as-you-go technique via the fiberoptic bronchoscope. METHODS: Fifty-two adult patients with a difficult airway were randomly assigned to 1 of 2 study groups to receive 2% (Group 1) or 4% lidocaine (Group 2) by a spray-as-you-go technique with the fiberoptic bronchoscope, in a double-blind manner. After airway topical anesthesia, awake fiberoptic orotracheal intubation (FOI) was performed. Level of sedation, time for each lidocaine spray in different targeted areas, total times for airway sprays, total dosages of lidocaine used for airway sprays, intubation times, and number of intubation attempts were noted. An independent investigator scored patients’ comfort during airway topical anesthesia, patients’ reaction, coughing severity, and intubating condition during awake FOI, and observed changes of arterial blood pressure and heart rate during each stage in the airway manipulation process. Serial blood samples were obtained for analysis of plasma lidocaine concentrations. RESULTS: Except for the total dosages and plasma concentrations of lidocaine, there were no significant differences in any of the observed variables between groups. All patients exhibited excellent or acceptable intubating conditions. The total dosages of lidocaine were significantly smaller in Group 1 (3.4 ± 0.6 mg/kg) than in Group 2 (7.1 ± 2.1 mg/kg). The plasma lidocaine concentrations in all observed points after the supraglottic sprays were larger in Group 2 than in Group 1. CONCLUSIONS: Both 2% and 4% lidocaine administered topically by a spray-as-you-go technique can provide clinically acceptable intubating conditions for awake FOI in sedated patients with a difficult airway. As compared with 4% lidocaine, however, 2% lidocaine requires a smaller dosage and results in lower plasma concentrations.

More maneuvers to facilitate endotracheal intubation using the Airtraq® laryngoscope in children with difficult airways

Surgical repair of the atresia auris congenita was performed successfully, and the tracheal tube was removed without adverse sequelae. The AOL provides a high-grade, indirect, close proximity view of the glottis without the need for alignment of the oral, pharyngeal, and laryngeal axes. The oropharyngeal airwayshaped blade allows laryngeal exposure with ease even in patients with difficult airways (1–5). In addition, the AOL has a guiding channel that directs the tracheal tube through the glottis; and hence, it facilitates tracheal tube insertion once the glottis is aligned with the center of the laryngeal inlet on the view field. The infant AOL accepts tracheal tube with an internal diameter between 2.5 and 3.5 mm; while the pediatric one accepts tube with an internal diameter between 3.5 and 5.5 mm. The pediatric AOL easily provided a full view of the glottic opening in our patient with Treacher Collins syndrome, in whom the Macintosh laryngoscopy failed to expose the glottis. Anesthesia resident completed tracheal intubation without difficulty within 40 s. The small-size AOL seems suitable for difficult airways in small children.

A simple maneuver to facilitate tracheal intubation using the Airtraq laryngoscope with a reinforced endotracheal tube.

videolaryngoscope (AWS) using straightvs curved reinforced endotracheal tubes (ETTs). It wasshown that tracheal intubation is more difficult withstraight reinforced ETTs than with curved reinforced ETTs.Regardless of using a straight or a curved reinforced ETT,our own clinical experience suggests that a posteriorETT tip location is a common problem during trachealintubation with the Airtraq laryngoscope, a device similarto the AWS. Due to this device’s wide tube conduit, theample space between the ETT and the tip of the Airtraqlaryngoscope is a contributing factor to the problem(Figure 1, Panel A).

Airway topical anesthesia using the Airtraq® laryngoscope in patients with difficult airways

To the Editor, The Airtraq laryngoscope (Prodol Meditec S.A., Vizcaya, Spain) is a new disposable optical laryngoscope designed to facilitate orotracheal intubation in an uncomplicated or difficult airway. Its distinctive shape and optical system can provide a full view of the glottis without the need to align oral, pharyngeal, and laryngeal axes. Previous studies have suggested that the device is both effective and easy to use in anesthetized patients with normal and difficult airways. We describe our initial experience with a method of airway topical anesthesia for awake tracheal intubation in adult patients with difficult airways using a combination of an Airtraq laryngoscope and a MADgic laryngotracheal atomizer (MAD-LTA) (Wolfe Tory Medical Inc., Salt Lake City, UT, USA) (Fig. 1). First, the patient’s oral cavity and posterior pharynx were anesthetized with atomized lidocaine in the preoperative holding area. In the operating room, fentanyl 1.5 mg kg and a low dose of midazolam were administered intravenously to achieve the desired level of sedation. A 5-mL Luer-locked syringe prefilled with 2% lidocaine was then connected to the applicator portion of the MAD-LTA. The distal end of the applicator portion was bent anteriorly to an angle of 70–80 to correspond with the distal curvature of the Airtraq laryngoscope. Next, an Airtraq laryngoscope without the endotracheal tube was passed into the patient’s mouth over the tongue in the midline. Once the distal end of the Airtraq laryngoscope was positioned in the vallecula with the glottis in the center of the viewfinder, the curved applicator portion of a MAD-LTA was advanced through the lateral channel of the Airtraq laryngoscope. By adjusting the distant position of the applicator portion under direct vision on the viewfinder, its tip was placed immediately superior to the glottis and the bilateral pyriform recess. Then, 3 mL of 2% lidocaine was sprayed in three aliquots onto these targeted areas with the MAD-LTA. This procedure was repeated within 3–5 min, but the applicator portion was advanced into the trachea with the tip positioned approximately 1 cm below the glottis. During inspiration, 3 mL of 2% lidocaine was sprayed into the trachea. After an additional 3 to 5-min period, awake orotracheal intubation was performed with the Airtraq laryngoscope according to the technique previously described. Based on our preliminary experience in 15 adult patients with known difficult airways (due to micrognathia, a short neck, and/or limited head and neck movement), several advantages appear to exist with this technique. First, because the Airtraq laryngoscope has a wide lateral channel, the applicator portion of the MAD-LTA can well be adapted to the curved blade of the Airtraq laryngoscope. Also, the tip of the MAD-LTA can be directed easily towards the different targeted airway structures by adjusting its distal position under the superior vision of the airway provided by the Airtraq laryngoscope. Second, this approach can provide excellent airway topical anesthesia for awake orotracheal intubation, because the MADLTA can provide effective atomized lidocaine solution to the airway mucosa. Third, this technique is well tolerated by the awake, sedated patient, possibly due to less stimulation of the oropharyngolaryngeal structures during the F. S. Xue, MD (&) J. H. Liu, MD X. Liao, MD Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China e-mail: fruitxue@yahoo.com.cn

Endotracheal tube obstruction by unexpected blood clot in anesthetized children: a report of three cases

McGaw, IL, USA) returned a small amount of clear-yellow secretions. ETCO2 and tidal volumes returned to normal. The patient was disconnected from the anesthesia circuit and positioned prone for the procedure. His face was placed on a foam pad (Pediatric Gentletouch 4; Orthopedic Systems, Inc., Union City, CA, USA), and the circuit was reconnected. Shortly after reconnecting the circuit, ETCO2 and tidal volumes decreased to zero, and breath sounds were absent. Positive-pressure ventilation by bag was ineffective. A kink in the tube was suspected, and the patient’s head was repositioned, with no improvement in ventilation. An 8F soft suction catheter was again inserted and upon withdrawal of the catheter, a white foreign body was noted in the endotracheal tube. The foreign body migrated distally with attempts at ventilation, and could not be withdrawn with the 8F catheter. A 10F soft suction catheter was passed, and the foreign body was retrieved. The patient’s oxygen saturation remained above 96% and his heart rate above 100 throughout this time. Tidal volumes and ETCO2 returned to normal, and the rest of the case was uneventful. The foreign body was a 12 · 4 · 5 mm piece of white foam. Upon further inspection, a small gouge in the foam face pad, near the premade passage for the endotracheal tube, was noted and was equal in shape and size to the foreign body. There are numerous case reports of foreign bodies recovered from airways and anesthesia circuits. There are fewer reports of anesthesia equipment obstructing the endotracheal tube. There may be a higher risk with smaller pediatric tubes, as demonstrated by this incident and those cited above. The step of disconnecting and reconnecting the endotracheal tube to the circuit always entails the risk of subsequent complications as the integrity of the circuit is temporarily disrupted. Visual inspection of the circuit should always be undertaken after any disconnection. However, in our situation, only the connector piece of the endotracheal tube was readily visible. The foreign body was initially thought to be a mucus plug, because our patient did have a recent URI and mild ventilatory difficulty at the beginning of the case. Fortunately, positive-pressure ventilation did not push the foam into the bronchial tree, which could have caused more serious complications and required bronchoscopy for retrieval. We are not aware of another instance of this specific complication, despite foam pads being used commonly for surgery in the prone position. Benjamin J . Walker Sally E. Rampersad Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Seattle Children’s Hospital, Seattle, WA 98105, USA (email: benjamin.walker@seattlechildrens.org)

Anesthesia and airway management for children with macroglossia

wire. Another modification to this technique is using an 8 Fr red rubber tube catheter attached to the insertion cord of the fiberscope (2). Unfortunately, no advanced airway aids of appropriate size were available to us. The operating laryngoscope, in contrast to the anesthesiologists’ conventional laryngoscope blades, Miller ⁄ Macintosh, which displace only anterior structures like tongue from the line of sight, is a hollow device that can displace posterior masses that intrude into the supraglottic region improving glottic view. In our case, the firm masses arising from the cartilaginous part of the larynx and intruding into the membranous part posed difficulty in tube negotiation .The hollow operating laryngoscope displaced the mobile masses to uncover a glottic chink resulting in successful intubation (Figure 3). The operating laryngoscope is a useful aid in the nonemergent limb of failed intubation. Rani A. Surender * Chakravarty Chandrashish* Kumud Kumar Handa† Subramaniam Rajeshwari* *Department of Anesthesiology and †Department of Otolaryngology, All India Institute of Medical Sciences, New Delhi, India (email: rani_kannan2000@yahoo.com)

Airway topical anesthesia using a rigid fiberoptic stylet in children with difficult airways.

Overall CP is Useful 82% Harmful 7.1% Both 3.2% Blank 7.1% Do you use succinylcholine when performing rapid sequence intubation? In Females 1.3% In both males and females 68% Never 29% No response 1.9% Do you always premedicate for aspiration prophylaxis? Yes 9.1% No 91% Do you use Succinylcholine when performance rapid sequence intubation? Females only 1.3% Both males and females 68% Never 29% Blank 1.9% Do you ever use bimanual CP? Yes 18.2% No 80% Blank 1.9% Table S-5 Contraindication of cricoid pressure as described by the respondents

Airway topical anesthesia using the Bonfils fiberscope.

LMA-S). The ETT can be left in place as long as an adequate tidal volume is delivered; it can be removed with the LMA-S after its priming with an ETT exchanger. The latter will work like a guidewire for blind tracheal intubation, if a larger ID ETT is required. Alternatively, a FOS is guided through the airway tube of the LMA-S. Once the vocal cords are visualized, a Frova airway introducer (Cook UK Ltd, Letchworth, Herts, UK) is advanced in the airway tube parallel to the FOS, until its precurved tip faces the laryngeal inlet (Fig. 1B). After successful tracheal insertion of the Frova introducer with gentle, proper handling, the FOS and LMA-S are removed. A âHi-Contourâ 7.5 mm ID, lubricated ETT (Mallinckrodt Medical) is then railroaded over the Frova [2]. An even more practical approach includes the use of the Aintree Intubation Catheter (AIC; Cook UK, Ltd.) as a guidewire. The AIC is a 57 cm long ventilation exchange catheter designed to enable fiberoptic-guided intubation of the trachea. A FOS is loaded with an AIC and passed through a self-sealing bronchoscopy catheter mount down the airway channel of an already placed LMA-S (Fig. 1C). After FOS/ AIC positioning into the patients trachea, the FOS and LMA-S are removed. A 7.5 mm ID ETT is railroaded over the AIC. Use of the AIC via a Classic LMA and a ProSeal LMA has been reported when conventional tracheal intubation has failed [3]. Studies are warranted to evaluate the feasibility of fiberoptic-guided intubation with LMA-S and the usefulness of this technique in difficult airway management scenario.

Further observations on retromolar fibreoptic orotracheal intubation in patients with severe trismus

To the Editor, We congratulate Truong et al. on their successful airway management using retromolar fibreoptic orotracheal intubation in a patient with severe trismus undergoing nasal surgery. We too have employed this technique in three adult patients during the past five years. The first case involved a 52-yr-old woman who suffered from a severely limited mouth opening (interincisor distance = 7 mm) due to previous radiotherapy for oral cancer. On this admission, she underwent nasal metastatic tumour excision and temporomandibular joint arthroplasty. The second case involved a 21-yr-old male with chronic temporomandibular joint ankylosis (interincisor distance = 5 mm), mandibular hypoplasia, and left nasal passage stenosis. He was scheduled for temporomandibular joint arthroplasty and surgery of the left nasal passage. The third case involved a 32-yr-old male with decerebrate rigidity secondary to brain trauma. He had severe trismus (interincisor distance = 0 mm), a basal skull fracture, and cerebrospinal fluid rhinorrhea, and he required orotracheal intubation for airway management because his legally responsible relative refused tracheotomy. In all three cases, retromolar fibreoptic orotracheal intubation was an effective choice to secure an airway for patients with concomitant severe trismus and contraindications to nasotracheal intubation. We offer several observations from our experience to facilitate use of retromolar fibreoptic intubation:

Airway topicalization during tracheal intubation using the Airtraq® laryngoscope in anesthetized patients

To the Editor, It has been shown that topicalization of the larynx and trachea before intubation can prevent increases in arterial blood pressure during intubation, while simultaneously decreasing the incidence of coughing on emergence from general anesthesia. In clinical practice, the larynx and trachea in patients with normal airways are usually anesthetized with local anesthetic sprays using various devices under direct laryngoscopy or occasionally with a help of the fibrescope in patients with difficult airways. The Airtraq laryngoscope (Prodol Meditec S.A., Vizcaya, Spain) is a new disposable optical laryngoscope designed to facilitate orotracheal intubation in an uncomplicated or difficult airway. This device is easy to use and effective to facilitate tracheal intubation in anesthetized patients with either normal or difficult airways. However, when an Airtraq laryngoscope loaded with an endotracheal tube (ETT) is inserted into the anesthetized patient’s mouth, it is impossible to use a common atomizer to anesthetize the larynx and trachea because there is limited access to place the atomizer towards the targeted airway area. The MADett endotracheal tube mucosal atomization device (MADett, Wolfe Tory Medical Inc., Salt Lake City, UT, USA) is a new device designed to spray medications directly into the lungs via the ETT without interrupting ventilation in the intubating patients. It is a disposable 50.8 cm flexible cannula with memory that generates a 30 lm particle spray of injected medications. Recently, we have successfully combined the Airtraq laryngoscope and the MADett to provide topicalization of the glottis and trachea during tracheal intubation in anesthetized patients. After obtaining institutional ethics committee approval and written informed consent, 30 patients with ASA physical status I–II, aged 19–57 yr, and undergoing elective surgery under general anesthesia during May and June 2009 were included in this study. Exclusion criteria included a history of severe hepatic, renal, or coagulation diseases; gastroesophageal reflux; pregnancy; a known allergy to any of the study drugs; and a known or predicted difficult airway. After loading the ETT on the lateral channel of the Airtraq laryngoscope, the flexible cannula of the MADett was inserted into the ETT with its tip close to but not protruding beyond the distal end of the ETT. By mounting an elbow connector, the MADett was joined to the connector of the ETT. A 5-mL luer-locked syringe prefilled with a liquid solution of 2% lidocaine was connected to the distal end of the MADett (Fig. 1). After routine pre-oxygenation, anesthesia was induced with fentanyl 2 lg kg and propofol 2 mg kg iv, and neuromuscular block was produced with vecuronium 0.1 mg kg iv. With the patient’s head and neck placed in a neutral position, the Airtraq laryngoscope was inserted into the patient’s mouth over the tongue in the midline. Once the distal end of the Airtraq laryngoscope was positioned in the vallecula with the glottis in the centre of the viewfinder, the ETT was slightly advanced through the lateral channel of the Airtraq laryngoscope until its tip was placed immediately superior to the glottis. At that F. S. Xue, MD (&) J. H. Liu, MD X. Liao, MD Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China e-mail: fruitxue@yahoo.com.cn; profxuefushan@xxmu.edu.cn