Lighted stylet tracheal intubation: a review.

To compare the tracheal intubation success rates of blind oral intubation using a lighted stylet vs standard of direct laryngoscopy in anesthetized pediatric patients wearing rigid cervical collars. Seventy-eight children were randomly assigned to method of intubation (lighted stylet or direct laryngoscopy) and intubator; five patients were excluded after randomization. After sedation and paralysis, the patients were placed in rigid cervical spine collars to simulate intubating conditions for trauma patients. Three attempts at intubation were allowed. An observer recorded the following parameters during the procedure: 1) number of intubation attempts, 2) duration of each intubation attempt, and 3) complications. The intubators had limited prior experience with the lighted stylet technique. Thirty-three patients were in the lighted stylet group and 40 were in the laryngoscopy group. The patients in the lighted stylet group required more attempts prior to successful intubation (2.2 vs 1.5, p < 0.01), and the success rate was higher for the laryngoscopy group (26/33 vs 39/40, p < 0.05). Blind oral intubation using a lighted stylet under controlled conditions took longer than direct laryngoscopy. However, among those successful on the first intubation attempt, the times to intubation were not significantly different between groups (44.5 vs 52.9 sec). The lighted stylet technique is a viable alternative technique for intubating children who have concurrent cervical spine immobilization.

Objective To estimate the clinical value of fiberoptic bronchoscopy(FOB)-guided tracheal intubation with laryngeal mask airway in anticipated difficult airways patients. Methods Twenty four ASA Ⅰ or Ⅱ patients scheduled for elective general anesthesia surgery with one or several difficult intubation criterion (thyromental distance<6 cm, 1.5 cm<interincisor distance<3 cm, head extension and neck movement limited <80 degree and Mallampati class Ⅲ or Ⅳ) were randomly allocated into 2 groups, 12 cases in each group. Patients in the LMA with FOB group (F group) underwent intubation with laryngeal mask airway with fiberoptic bronchoscope and patients in the direct laryngoscope group (L group) underwent direct intubation with laryngeal scope orally. If failed three times using direct laryngeal scope, intubate according to the F group method. Record patients airway assessment and the MAP and heart rate before(basement) and 3 min after intubation, the intubation time and the times of intubation successful. All the patients were followed up postoperatively for adverse effects like sore throat or hoarseness. Results Airway assessments of the patients in the two groups before intubation had no difference(P>0.05). Compared with the value of basement, the MAP and HR increased significantly in the patients of the L group(P 0.05). There is significant difference between L group and F group(P< 0.05). The first intubation attempt succeeded in 75% of the patients in the F group and the total success rate was 100%, though the success rate was only 25% at the first attempt in the L group and the total rate of success was 50% after three attempts. Six cases failed with direct laryngeal scope after three attempts, then two of them intubated successfully with FOB aided by LMA at the first attempt and four of them succeeded at the second time. The rate of success of first attempt and the total rate of three attempts in the F group were higher than the L group. There was significant difference between the two groups (P<0.05). The duration of intubation in the F group was shorter significantly than that in the L group [(81±9) s vs (161±26) s ](P<0.05). There were two cases in the F group who had mild sore throat. Six cases had moderate to severe sore throat and mild hoarseness and two cases had mild sore throat in the L group. Conclusions Laryngeal mask airway combining with fiberoptic bronchoscope intubation in anticipated difficult airways was effective to improve the success rate of intubation and reduce adverse effects of direct laryngoscope intubation postoperatively. It is worthy of clinical application. Key words: Difficult airway; Intubation, Intratracheal; Laryngeal mask; Fiberoptic bronchoscope

BackgroundFor successful lighted stylet intubation, bending the lighted stylet with an appropriate angle is a prerequisite. The purpose of this study was to compare three different bend angles of 70, 80, and 90 degrees for lighted stylet intubation.MethodsThe patient trachea was intubated with a lighted stylet bent at 70, 80, or 90 degrees according to the randomly allocated groups (group I, II, and III, respectively). A lighted stylet combined with a tracheal tube was prepared with a bend angle of 70, 80, or 90 degrees according to the assigned group. We checked the success rate at the first attempt and overall success rate for the two attempts. Additionally, we measured search time, which was time from insertion of the bent union into the patient mouth to the start of advancing the tracheal tube while separating it from the lighted stylet, and evaluated postoperative sore throat (POST) at 2, 4, and 24 h after the recovery from anesthesia.ResultsThere was no statistically significant difference between group I, II, and III for success rate at first attempt (73.9 %, 88.2 %, and 94.7 %, respectively, p = 0.178), even though there was a trend of increasing success rate with increasing bend angles. For overall success rate, there was similar result to that in the first attempt between the groups I, II, and III (82.6 %, 94.1 %, and 100 %, respectively, p = 0.141). However, search time took significantly longer in group I than groups II and III (p < 0.001). When group II and III were compared for POST with numeric rating scale (0–10), it was significantly lower in group II than III at 2, 4 h after the recovery (0.5 vs. 2.3, p = 0.016, and 0.4 vs. 1.8, p = 0.011, respectively).ConclusionsThe bend angle of the lighted stylet affected the time required for tracheal intubation and POST in our study. 80 and 90 degrees as a bend angle seem to be acceptable for clinicians in regard to success rate of lighted stylet intubation. Considering the success rate of lighted stylet intubation and POST, the bend angle of 80 degrees might be better than 70 and 90 degrees.Trial registrationClinicalTrials.gov Identifier NCT03693235, registered on 30 September 2018.

Background: Direct laryngoscopy with the Macintosh laryngoscope is the standard technique for endotracheal intubation during general anaesthesia. However, laryngoscopy and intubation can provoke sympathetic stimulation leading to tachycardia and hypertension. The Intubating Laryngeal Mask Airway (ILMA) is an alternative airway device that allows ventilation and blind tracheal intubation without direct laryngoscopy. Objective: To compare the hemodynamic responses and intubation characteristics of tracheal intubation using direct laryngoscopy and ILMA in patients undergoing elective surgery under general anaesthesia. Methods: This prospective randomized comparative study included 110 adult patients aged 18–65 years with ASA physical status I–II scheduled for elective surgery under general anaesthesia. Patients were randomly divided into two groups of 55 each: Group M underwent intubation using direct laryngoscopy with Macintosh blade, and Group I underwent intubation using ILMA. Hemodynamic parameters including heart rate, systolic blood pressure, diastolic blood pressure, and mean arterial pressure were recorded at baseline, before intubation, during intubation, and at 1, 2, 5, and 10 minutes after intubation. Intubation time, success rate, and complications were also assessed. Results: The mean intubation time was significantly shorter in Group M compared with Group I (p &lt; 0.05). The first-attempt success rate was higher in Group M, although the overall success rate was 100% in both groups. Hemodynamic parameters showed transient increases during intubation in both groups without significant differences. Conclusion: Direct laryngoscopy provides faster tracheal intubation with a higher first-attempt success rate, while ILMA offers comparable hemodynamic stability and can be considered a feasible alternative airway device.

Objective To evaluate the effect of awake tracheal intubation with intubating larynegeal mask airway(ILMA)on stress responses of hypertensive patients. Methods Sixty hypertensive patients, aged 45-64 yr, with body mass index of 20.3-27.5 kg/m2, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, undergoing elective abdominal surgery under general anesthesia, were divided into 2 groups(n=30 each)using a random number table: direct laryngoscope group(group D)and ILMA group(group I). At 3 min after topical anesthesia(T1), while epiglottis and glottis were exposed with direct laryngoscope in group D or during ILMA insertion in group I(T2), immediately after completion of intubation(T3), when the maximum change in hemodynamics after intubation appeared(at about 15 s after tracheal tubes were placed, T4), and at 5 min after completion of intubation(T5), mean arterial pressure(MAP)and heart rate(HR)were recorded, and blood samples were collected for determination of plasma epinephrine concentrations by radio-immunity method.Successful intubation at first attempt was recorded. Results Compared with the parameters at T1, the MAP, HR and plasma epinephrine concentrations were significantly increased at T2-4 in group D(P 0.05). Compared with group D, the MAP, HR and plasma epinephrine concentrations were significantly decreased at T2-4(P 0.05). Conclusion Awake tracheal intubation with ILMA does not induce strong stress responses and is helpful in avoiding the occurrence of cerebrovascular accidents, thus increasing the safty of awake tracheal intubation in hypertensive patients. Key words: Hypertension; Laryngeal masks; Intubation, intratracheal

To the Editor, When encountering patients with difficult airways in pediatric anesthesia, clinicians have the option of using a supraglottic airway device as a conduit for tracheal intubation. The Laryngeal Mask Airway (LMA) Classic (LMA North America; San Diego, CA, USA) is the conduit used most commonly for tracheal intubation in the pediatric population. However, numerous challenges arise when the LMA is used to facilitate intubation with an endotracheal tube (ETT), especially during removal of the LMA following successful intubation. In particular, the airway tube of the LMA can be as long as the ETT, making it difficult to maintain control of the ETT while removing the LMA. Several techniques that decrease the likelihood of accidental extubation of the ETT during removal of the LMA have been devised and reported in the literature. These techniques include the use of a long ETT, a double ETT assembly, shortening or splitting the shaft of the LMA, or leaving the LMA in place for the duration of surgery. These techniques are all effective yet imperfect solutions to a procedure commonly encountered in a patient with a difficult airway. The air-Q intubating laryngeal airway (ILA) (Cookgas LLC; St. Louis, MO, USA) is a newer supraglottic airway device that holds several advantages over the LMA when used to facilitate tracheal intubation in the pediatric population. Specifically, the airway tube of the ILA is shorter and wider than the LMA, which allows for greater control of the ETT and unhindered passage of the pilot balloon during removal of the ILA. At our institution, we have intubated the tracheas of hundreds of patients successfully by using the ILA as a conduit for tracheal intubation. It has been noted that the shorter airway tube length greatly facilitates distal control of the ETT and subsequent removal of the ILA after intubation. Unlike the LMA, the ILA has a custom removal stylet that can be used to stabilize the ETT during removal of the ILA device. However, if the manufacturer’s removal stylet is not available or if the clinician is not comfortable with its use, we propose the use of an airway exchange catheter (AEC) (Cook Medical, Bloomington, IN, USA) to facilitate removal of the ILA (Figure). Use of an AEC during removal of the ILA offers advantages to the clinician who otherwise might be hesitant to remove the ILA after tracheal intubation. First, placement of the AEC maintains the ability to supply supplemental oxygen into the trachea and diminishes the possibility of oxygen desaturation. Second, the AEC provides a means for guided reintubation if the ETT is dislodged inadvertently during removal of the ILA device. Generally, the smaller-sized ILAs (1.0 and 1.5) are short enough to facilitate gaining both proximal and distal control of the ETT during removal of the ILA. If an AEC is used, the clinician could cede control of the ETT once its proximal end is flush with the ILA and still retain proximal control of the AEC to ensure it remains in the trachea. The clinician can then remove the ILA until distal control of the ETT is possible, even if outside the patient’s mouth, and then confirm tracheal depth and reintubate over the AEC if necessary. Another potential technique that has been described for tracheal intubation through the LMA is to leave the fibreoptic bronchoscope within the trachea while removing the LMA, then to advance the ETT down the bronchoscope into the trachea. This method is beneficial, as no additional N. Jagannathan, MD (&) R. J. Kozlowski, BS Children’s Memorial Hospital, Northwestern University’s Feinberg School of Medicine, Chicago, IL, USA e-mail: simjag2000@yahoo.com

Objective To evaluate the efficacy of Ambu AuraOnce laryngeal mask airway (LMA) in Chinese patients undergoing general anesthesia. Methods Fifty-six female patients, aged 20-64 yr, weighing 45-75 kg, of American Society of Anesthesiology physical statusⅠor Ⅱ (MallampatiⅠ-Ⅲ), scheduled for elective breast surgery under general anesthesia, were equally and randomly divided into either Ambu AuraOnce LMA group (group A) or LMA Supreme group (group S) using a random number table. After induction of anesthesia, Ambu AuraOnce LMA was inserted in group A, and LMA Supreme was placed in group S. After successful placement of LMA, correct position was confirmed by fiberoptic laryngoscopy. Intermittent positive pressure ventilation was performed during surgery to maintain pulse oxygen saturation > 95% and partial pressure of end-tidal CO2 at 30-45 mmHg. The success rate, insertion time, extubation time, airway sealing pressure, peak airway pressure and occurrence of air leakage of LMA were recorded. After removal of the LMA, the blood stains on the LMA were checked, and the occurrence of hypoxemia, regurgitation, nausea, vomiting and bucking was recorded. The occurrence of sore throat, hoarseness and dysphagia was also recorded within 24 h after surgery. Results There were no significant differences in terms of insertion time, overall success rate, success rate at first attempt, removal of LMA time, airway sealing pressure, and incidence of air leakage of LMA, hypoxemia, blood stains on the LMA, sore throat, hoarseness and dysphagia between the two groups. The rate for correct position of LMA confirmed by fiberoptic laryngoscopy was significantly higher in group A than in group S. Conclusion Ambu AuraOnce LMA can safely and effectively be applied for airway management in Chinese patients undergoing general anesthesia. Key words: Laryngeal masks; Respiration, artificial; Anesthesia, general

The Laryngeal Mask and High-Frequency Jet Ventilation for Resection of High Tracheal Stenosis

A fundamental skill of the anesthesiologist is airway management. We validated a simple endotracheal intubation algorithm with a large proportion of fiberoptic tracheal intubations used for years in daily practice. Over 2 yr, 13,248 intubations (>90% of all intubations, including obstetrics and ear, nose, and throat patients) in a heterogeneous patient population at our acute care hospital were evaluated prospectively. About 80 physician and nurse anesthetists were involved. Once the indication for intubation (oral or nasal) was established, the first step was to choose between the primary conventional technique (laryngoscope with Macintosh blades) and the primary fiberoptic technique. For the conventional technique, a well defined procedure had to be followed (maximum of two attempts at intubation; if unsuccessful, switch to secondary oral fiberoptic intubation). For the primary fiberoptic technique, the anesthesiologist had to decide between nasotracheal intubation in awake patients and oral intubation in anesthetized patients. Fiberoptics were used for 13.5% of the intubations. By following our algorithm, intubation failed in 6 out of 13,248 cases (0.045%; 95% confidence interval 0.02%-0.11%). We demonstrate that a simple algorithm for endotracheal intubation, basically limited to fiberoptics as the only aid, is successful in daily practice. Only methods that are practiced daily can be used successfully in emergencies.

Blind Nasal Intubation Revisited: No Longer a Blind Technique?

Unanticipated difficult endotracheal intubation due to an undiagnosed pharyngeal web

Anaesthesiologists are regularly faced with difficult tracheal intubation. The objective of the study was to evaluate the feasibility and tolerability of tracheal intubation with the Bonfils intubating fibrescope in awake adult patients with predicted difficult intubation undergoing cancer surgery in an ear, nose and throat unit. Intubation was performed under local anaesthesia and remifentanil sedation with spontaneous ventilation. The primary endpoint was the proportion of intubations which met the following quality requirements: successful intubation (≤ 2 attempts and duration <180 s) and good tolerability (Fahey scale <2). Secondary endpoints included the operational problems encountered and patients' perception of the procedure immediately and 7 days after the intervention. Using a one-stage Fleming design, 32 patients were required to complete the study. Forty-one eligible adult patients were enrolled. Between February 2008 and March 2009, the primary endpoint could be evaluated in 33 patients. Quality requirements were met in 26 patients (78.8%) and not met in seven patients (five were intubated with the Bonfils fibrescope and two using another technique). Difficulties were reported in 13 patients (39.4%). Eighty-four percent of the patients had a good or very good perception of the intubation shortly after the procedure, and 91% after 7 days. Tracheal intubation using the Bonfils intubating fibrescope was successful in almost all patients (93.9%). The 78.8% incidence of interventions which met the quality requirements is high in the context of ear, nose and throat cancer and acceptable in current clinical practice. In ear, nose and throat cancer patients who do not require nasopharyngeal intubation and in whom orotracheal intubation is predicted to be difficult, the use of the Bonfils intubating fibrescope is safe, effective and well tolerated. NCT01070537, URL: http://clinicaltrials.gov/ct2/show/NCT01070537?term=bonfils&rank=2.

Background: Preservation of patient’s spontaneous respiration and consciousness are most important recommendations in any one of difficult airway. Under adequate upper airway block, awake intubation could be performed through oral or nasal routes using fibre optic visualization or blind nasal techniques. This work was designed to compare the applicability of awake blind nasal intubation and that of fibre optic naso-trachael intubation. Materials and Methods: Sixty patients were distributed randomly into two groups of thirty patients each, Group A (fibre optic intubation) and Group B (Blind nasal intubation) After pre-operative evaluation, patients in both the groups were given lidocaine nebulisation 4% (5ml) and bilateral SLN and RLN blocks. Patients were intubated with fibre optic and blind nasal intubation techniques according to their groups. Tube placement in trachea was confirmed by ETCO2. In both the groups, comparison regarding time taken for intubation, no of attempts of intubation, hemodynamic changes and side effects / complications were done. Results: Intubation time in group A was significantly less than that of group B. (P<0.05). Intubation under first attempt was significantly higher in group A than group B. Haemo-dynamic parameters were also comparable. No major side effects/complications were observed. Conclusion: We concluded that, both blind nasal and fibre optic tracheal intubation are of gold standard in patients with no or reduced mouth opening. However fibre optic nasal intubation requires less time and less number of attempts for intubation with minimal haemodynamic changes and have low incidences of complications.

There are many studies in India that have compared direct laryngoscopy and video laryngoscopy in adults but the published data regarding paediatric population which needs special consideration is limited. The present study was aimed to compare the efficacy of video laryngoscopy and direct laryngoscopy in endotracheal intubation in paediatric patients.The present randomised controlled research was done in 64 children of one to five years that underwent pre-planned surgery. Children were divided into direct laryngoscopy and video laryngoscopy groups by randomization. The comparison of the time required for the best visualisation of glottis was the primary outcome measure. The comparison of the time to intubation and number of attempts were the secondary outcome measures. An unpaired student’s t-test and the Chi-square/ Fisher’s exact tests were used to compare the quantitative and qualitative variables respectively.Mean time required for the best visualisation of video laryngoscopy and direct laryngoscopy was 6.1 sec and 5.3 sec respectively (p-value = 0.010). The mean time to intubation of video laryngoscopy was 15.3 sec while that of direct laryngoscopy was 13.1 sec (p-value = 0.001). The first attempt success rate was 29/32 (90.6%) in the video laryngoscopy group whereas it was 28/32 (87.5%) in the direct laryngoscopy group (p-value = 0.580).Time required for the best visualisation of glottis and time to intubation were significantly higher in video laryngoscopy as compared to direct laryngoscopy group.

Epiglottic cysts sometimes compromise a patient's airway, and may make airway management difficult. We report a novel method of intubating a patient with a large epiglottic cyst, using direct laryngoscopy and a light wand. A 53-year-old man with hoarseness was admitted to the hospital. He complained of a mild cough and sore throat for 2 days, without dyspnea. General anesthesia for microscopic laser surgery was planned. Neck computed tomography revealed a nearly non-enhancing cyst, 2.7 × 1.8 × 3.3 cm, located on the right prelingual surface of the epiglottis (Figs. 1A and 1B). Fig. 1 Neck computed tomography (CT) revealed a nearly non-enhancing cyst in the right pre-epiglottic space with concomitant mild airway obstruction ([A] Transverse and [B] Sagittal views). (C) This image shows direct laryngoscope, light wand and laser tube ... In addition to standard monitoring and preparations, we prepared laryngeal mask airways, adult and pediatric fiberoptic bronchoscopes, and an emergency cricothyrotomy kit at the bedside. Two attending anesthesiologists and one resident were present in the operating room. After preoxygenation, propofol 120 mg was given. The patient became unconscious, and we confirmed there was no difficulty with mask ventilation. We then administered rocuronium 25 mg intravenously. After 4 minutes, we attempted intubation with a Macintosh blade no. 3 and 5.0 laser tube (Laser-Flex® Tracheal Tube, Mallinckrodt, St. Louis, MO, USA) without stylet. We carefully placed the tip of the Macintosh blade at the vallecula, avoiding direct pressure on the cyst. After that, an assistant held the handle of the laryngoscope steady. The intubating anesthesiologist then held the hockey stick-shaped light wand in the left hand and used it both for leverage and as a light source. Gently elevating both the epiglottis and cyst with the light wand in the upper left direction revealed the lower third of the glottis with sufficient light. We then intubated the patient. After intubation, we began mechanical ventilation with air. Tidal volume was set to 500 ml, respiration rate was 12 per minute, and peak airway pressure was 26 cmH2O. Anesthesia was maintained with sevoflurane 1.5-2.0 vol% and remifentanil continuous infusion of 0.1-2.0 mcg/kg/min. Oxygen saturation was maintained at a minimum of 95% throughout the surgery and in the recovery room. The patient recovered and was discharged after 1 day without any adverse events. Most epiglottic cysts are located on the lingual surface or vallecula, which makes intubation difficult, when a cyst is large. For the treatment of epiglottic cysts, simple aspiration of the cyst results in frequent recurrence, so complete removal is recommended [1]. For this removal, laser surgery seems to be superior to cold instrument surgery, in many respects. During laser surgery, the use of laser resistant endotracheal tubes is recommended to avoid catastrophic airway fires. There are several choices for laser resistant endotracheal tubes, including wrapping metal foil around conventional tubes, Xomed Laser-Shield (Laser-Shield®II Endotracheal Tube, Medtronic Xomed, Jacksonville, FL, USA), and Mallinckrodt Laser-Flex. Inevitably, methods or tubes such as these are accompanied by an increase in the wall thickness of the tubes. With the Laser-Flex, for example, the outer diameter (OD) of the tubes is at least 2.5 mm greater than the internal diameter (ID). This number is considerable in comparison to the thickness of conventional tubes, which is 1.3 mm at minimum. In our case, when intubation was attempted, the epiglottic cyst blocked the light from the laryngoscope, so structures behind the cyst were not visible (Fig. 1C). To circumvent this problem, there are several possible options. First, we could use a Miller blade or a Magill blade. Holding the epiglottis from the lower surface, together with the cyst, may allow direct visualization of the vocal cords without blockage of the light. However, considering the size of the cyst, this maneuver might fail. In addition pressure of the blade may rupture the cyst and cause pulmonary aspiration of its contents. Second, we could aspirate the contents of the cyst and then try the conventional intubation method. If the mass was not entirely cystic, or lobulated, the chances of success would be slim. Furthermore, attempting aspiration without first securing the airway may significantly increase the risk of pulmonary aspiration of cyst contents. Lastly, we could choose larger diameter tubes to use a light wand, intubating stylet, or fiberoptic bronchoscope. For airway surgery, though, it is rational to choose the smallest tubes possible to facilitate the surgery. We chose an ID 5.0 Laser tube, the OD of which is equivalent to the OD of an ID 5.5 conventional tube. The OD of an adult fiberoptic bronchoscope used for awake intubation is 5.0 mm, the same as the ID of the Laser tube. The OD of a light wand is 5.55 mm, still larger than the ID of the tube. The OD of the intubating stylet was 4.65 mm, but due to small differences between the ID of the tube and the OD of the stylet, using it was impossible. In patients with more difficult airways, it may be rational to choose a Laser-Flex tube with a bigger ID and use a stylet in it, but this also may be difficult because of the dimmed light caused by the cyst. A light wand may still be difficult to use because of the large OD of a light wand for an ID 6.0 Laser tube. The difference in diameter between the two is only 0.45 mm. Laser tubes are rigid and difficult to use with a fiberoptic bronchoscope. In addition, to use an adult bronchoscope, one must use a tube with an ID larger than 6.0 mm. A McCoy blade can be helpful in some situations. In our case it might be effective, but considering the size and the location of the cyst, even elevating the epiglottis might not make it possible to move the cyst away from the light source. In actuality, levering of the epiglottis in the ventral and cranial direction would move the cyst closer to the light source and might make the view dimmer. Using a fiberoptic bronchoscope or light wand in the presence of a large epiglottic cyst is also a difficulty, because of the mass blocking the passage. Recently, Choi et al. [2] reported a case of intubation of a patient with a large glottic mass. In their report, introducing a flexible bronchoscope was difficult and ultimately not possible, in spite of attempts at guidance and visualization with the GlideScope® (Verathon Inc., Bothell, WA, USA) video laryngoscope. The authors did not report the size of the mass in their case, but the picture included in their report shows similarity to our case. Epiglottic cysts poses great challenges for anesthesiologists in some cases. Our method can be a relatively easy, less invasive, simple method dealing with some large epiglottic cysts.