Transtracheal Injection Research Articles

A spray-as-you-go airway topical anesthesia attenuates cardiovascular responses for double-lumen tube tracheal intubation

BackgroundSpray-as-you-go (SAYGo) airway topical anesthesia and nerve block are common techniques used during awake tracheal intubation. However, their effects have not been described during double-lumen tube intubation. We report on a prospective randomized study that aimed to compare the intubation effects of SAYGo and nerve block patients undergoing thoracic surgery.MethodsSixty-six American Society of Anesthesiologists (ASA) physical status I and II patients were scheduled to undergo double-lumen tube (DLT) tracheal intubation for thoracic surgery. The patients were randomly assigned into control (Group C), ultrasound (Group U), and flexible intubation scope (Group F) groups with 22 cases in each group. Patients in Group C were induced with a standard anesthetic regimen. Patients in Groups U and F were treated with superior laryngeal nerve (SLN) block combined with transtracheal injection (TTI) and given a SAYGo airway topical anesthesia before intubation. Hemodynamic variables during intubation process were recorded as the primary outcome. Additional patient data were recorded including the occurrence of adverse events, the level of hoarseness, the occurrence of sore throats, memory function and the level of patient satisfaction with anesthesia.ResultsThe blood pressure (BP) and heart rate (HR) of patients in group C was significantly increased 1 min after tracheal intubation (P < 0.05) compared to before anesthesia. The BP and HR of patients in Groups U and F remained stable. 10 cases of hypertension were observed in Group C, 6 cases in Group U and 1 case in Group F. In Group C, tachycardia was observed in 9 patients along with 9 cases in Group U and 4 cases in Group F. In Group U, 4 patients experienced puncture and bleeding were and 8 patients had a poor memory of TTI. No significant differences were found in the incidence of hoarseness, sore throats, and satisfaction with anesthesia in postoperative follow-up.ConclusionsSAYGo airway topical anesthesia and SLN block combined with the TTI technique can inhibit the cardiovascular response during DLT tracheal intubation. The SAYGo technique has fewer complications and more advantages compared to other approaches.

A Comparative Study between Local Dexmedetomidine and Intravenous Dexmedetomidine during Awake Fiberoptic Nasotracheal Intubation.

Awake fiberoptic intubation (AFOI) is the gold standard for managing a difficult airway. To make the patient comfortable and cooperative during the procedure, many drugs such as benzodiazepines, opioids, or dexmedetomidine are used. Most of these intravenously given drugs may cause respiratory depression and hypoxia. We compared the efficacy of dexmedetomidine through nebulization and transtracheal route with intravenous routes with the primary aim of comparing patient tolerance score (PTS) and secondary objectives of comparing sedation score, cough score, and total duration required for awake fiberoptic nasotracheal intubation. This study was a prospective randomized double-blind study. Seventy-six patients, scheduled for elective surgery requiring AFOI between 18 and 75 years, were included in the study. They were randomly divided into two groups of 38 each. Group I patients received intravenous dexmedetomidine 1 μg.kg-1 and Group L patients received local dexmedetomidine through nebulization 0.5 μg.kg-1 and transtracheal injection 0.5 μg.kg-1. Statistical Package for the Social Sciences version 22 was used. Patients who received dexmedetomidine through nebulization and transtracheal route have significantly better PTSs and less cough scores as compared to patients who received dexmedetomidine by intravenous route (P < 0.05). Hemodynamic parameters and sedation scores between the two groups were statistically insignificant (P > 0.05). The time required for the procedure was significantly less in Group L compared to Group I (P < 0.05). Dexmedetomidine by nebulization and transtracheal route provides optimal conditions for AFOI with good patient tolerance and less cough score as compared to the intravenous route.

Necrostatin-1 attenuates Caspase-1-dependent pyroptosis induced by the RIPK1/ZBP1 pathway in ventilator-induced lung injury

BackgroundVentilator-induced lung injury (VILI) is a complex pathophysiological process leading to acute respiratory distress syndrome (ARDS) and poor outcomes in affected patients. As a form of programmed cell death, pyroptosis is proposed to play an important role in the development of ARDS. Here we investigated whether treating mice with the specific RIPK1 inhibitor Necrostatin-1 (Nec-1) before mechanical ventilation could inhibit pyroptosis and alleviate lung injury in a mouse model. MethodologysAnesthetized C57BL/6J mice received a transtracheal injection of Nec-1 (5 mg/kg) or vehicle (DMSO) 30 min before the experiment which was ventilated for up to 4 h. Lung damage was assessed macroscopically and histologically with oedema measured as the wet/dry ratio of lung tissues. The release of inflammatory mediators into bronchoalveolar lavage fluid (BALF) was assessed by ELISA measurements of TNF-α,interleukin-1β (IL-1β), and IL-6. The expression of RIPK1, ZBP1, caspase-1, and activated (cleaved) caspase-1 were analyzed using western blot and immunohistochemistry, and the levels of gasdermin-D (GSDMD) and IL-1β were analyzed by immunofluorescence staining. ResultsHigh tidal ventilation produced time-dependent inflammation and lung injury in mice which could be significantly reduced by pretreatment with Nec-1. Notably, Nec-1 reduced the expression of key pyroptosis mediator proteins in lung tissues exposed to mechanical ventilation, including caspase-1, cleaved caspase-1, and GSDMD together with inhibiting the release of inflammatory cytokines. ConclusionNec-1 pretreatment alleviates pulmonary inflammatory responses and protects the lung from mechanical ventilation damage. The beneficial effects were mediated at least in part by inhibiting caspase-1-dependent pyroptosis through the RIPK1/ZBP1 pathway.

Comparison between Intravenous Dexmedetomidine and Spray as you Go with 4% Lignocaine Versus Intravenous Fentanyl and Transtracheal Injection of 4% Lignocaine for Awake Nasotracheal Intubation with Flexible Vedioscope - A Randomized Single-Blind Prospective Study.

Background:Awake fiber-optic bronchoscopy-guided intubation is the method of choice in difficult airway which requires effective airway anesthesia to ensure patient comfort and acceptance.Aims:This study was conducted to assess the quality of airway anesthesia, patient comfort during intubation, and postoperative satisfaction of patients.Settings:Patients posted for surgeries under general anesthesia with Mallampati Grade I and II in a medical college. Patients were followed in the operation theater and postoperative ward.Study Design:This was a prospective randomized single-blind study.Materials and Methods:Group D received intravenous (i.v.) dexmedetomidine 1 μg.kg−1 i.v. over 10 min and 3 ml of 4% lignocaine spray as you go (SAYGo). Group F received i.v. fentanyl 2 μg.kg−1 over 10 min and transtracheal injection 3 ml of 4% lignocaine. Parameters assessed were endoscopic time, intubating condition, vocal cord position, cough severity, comfort during intubation, postoperative patient satisfaction, and any adverse effects such as sore throat, hoarseness, unpleasant memories, and hemodynamic response during intubation.Statistical Analysis:Independent Student's t-test, Mann–Whitney, Chi-squared test, or Fisher's exact test were used. P ≤ 0.05 was considered statistically significant.Results:Intubating conditions, vocal cord position, cough severity, comfort during intubation, and postoperative patient satisfaction were statistically significant (P ≤ 0.05) in favor of Group D though endoscopic time was longer.Conclusion:IV dexmedetomidine with SAYGo is effective than IV fentanyl with transtracheal block for awake fiber-optic videoscopic intubation in terms of intubating conditions, vocal cord position, cough severity, comfort during intubation, and postoperative satisfaction of patients with significant attenuation of postintubation hemodynamic response and better preservation of respiration though endoscopic time is more.

Outer membrane vesicles derived from hypervirulent Klebsiella pneumoniae stimulate the inflammatory response

Hypervirulent Klebsiella pneumoniae (hvKP), an increasing important pathotype, was initially recognized as a cause of severe liver abscesses and subsequently as a cause of other complications posing a clinical threat. Outer membrane vesicles (OMVs) secreted from abundant gram-negative bacteria are considered an important vehicle for delivery of effector molecules to target cells. However, the products and role in bacterial pathogenesis of OMVs secreted from hvKP, have not yet been determined. In order to examine the production of OMVs from hvKP and to determine their effects on the stimulation of the host innate immune response, we used ultracentrifugation to obtain homogeneous OMVs from hvKP ATCC 1706 cultured in vitro. Proteomic analysis was performed and hvKP OMVs were found to contain diverse proteins. Furthermore, hvKP OMVs exhibited discrepant cytotoxic effects on different cell types, in vitro. The vesicles induced the expression of proinflammatory cytokines including interleukin (IL)-6 and IL-8 in host cells. In addition, transtracheal injection of hvKP OMVs in wild-type mice led to an inflammatory response manifested by elevated levels of pro-inflammatory mediators including IL-6, IL-8 and TNF-α in bronchoalveolar lavage fluid (BAL), in accord with in vitro experiments. However, hvKP OMVs were insufficient to kill mice. In summary, OMVs originating from hvKP may serve to provoke the inflammatory response.

Comparison of Intubating Conditions using “Spray-as-You-Go” Technique versus Transtracheal Instillation of Lignocaine for Airway Topical Anesthesia during Awake Nasal Fiberoptic Intubation

Introduction: Awake fiberoptic intubation (AFOI) is the gold standard for the management of recognized difficult airway. Good airway anesthesia along with sedation is necessary to ensure patient comfort. Aim: The aim of the study was to evaluate topical lignocaine administered by “spray-as-you-go” versus transtracheal injection technique on intubating conditions during AFOI. Patients and Methods: After obtaining written informed consent, 36 patients were randomly allocated to one of two groups: Group T – transtracheal technique and Group S – Spray-as-you-go technique. All patients were sedated with intravenous dexmedetomidine infusion titrated to a Ramsay Sedation Score of 2–3 during AFOI. All patients received oral gargle and nasal packing with lignocaine 2%. Patients in Group T received 2 mL lignocaine 2% intratracheally just prior to beginning fiberscopy. Patients in Group S received 2 mL lignocaine 2% spray over the vocal cords and another 2 mL below the vocal cords during fiberscopy. Tracheal intubation was then performed. Primary outcome measure was a composite score of patient comfort. Secondary measures were intubation and fiberscopy time, adverse effects, and postoperative patient evaluation. Results: The demographic data were comparable. A composite score of <10 was considered optimal, 10–15 as acceptable, and >15 unacceptable. Significantly more patients in Group T had optimal composite score compared to Group S. There were no differences between the two groups as regards postintubation score, ease of intubation, and postoperative survey. Conclusion: During awake nasal fiberoptic intubation, in comparison with spray-as-you-go technique, the transtracheal instillation of lignocaine improves patient tolerance and comfort during tracheal intubation and provides better patient satisfaction.

DOZ047.121: Usefulness of conservative treatment in recurrent tracheoesophageal fistula in children

Abstract Introduction Recurrent tracheoesophageal fistula (TEF) is a challenging complication in children with repaired esophageal atresia (EA). Thoracotomy, with surgical repair, is the traditional therapeutic approach, however it is often associated with a significant morbidity and technical difficulty. Endoscopic techniques, from the tracheal and/or esophageal side, have recently been proposed as a primary treatment, in order to prevent reoperation especially in previously operated fields. Aim of this retrospective study is to present our experience as Tertiary Care Center and Referral Center for EA, on the endoscopic management of recurrent TEF in children with repaired EA. Method This is a retrospective study conducted on children with repaired EA referred at Bambino Gesù Children's Hospital from January 2009 to January 2019. Demographic and clinical details, including type of EA, presence of fistula, concomitant malformations, endoscopic evaluation, number and kind of treatments, performed were collected. Results We identified 171 patients with EA, 15 type 1 (9%), 7 type 2 (4%), 140 type 3 (82%), 6 type 4 (3%), 3 type 5 (2%). Among patients with TEF, 11/156 (7%- M:F/6:5) presented with a TEF recurrence. Among the latter, 5 (45.4%) were patients with concomitant malformation (2 VACTER, 2 anorectal malformation, 1 Down syndrome, cardiac abnormalities, and hypothyroidism). All patients with TEF recurrence presented with symptoms, such as chronic cough, vomit, bronchitis, recurrent pneumonia, and failure to thrive. All patients underwent endoscopic evaluation both from digestive and tracheal side. Six (6/11–54.5%) patients underwent surgery, 5 patients (5/11–45.4%) were treated with endoscopic transtracheal fibrin glue injection after brushing that was successful in two patients (2/5–40%), one patient needed a retreatment. These patients maintained successful closure after treatment confirmed at endoscopic follow-up. Remaining three patients needed surgical approach during follow-up. Conclusion Endoscopic repair of recurrent TEF has proved safe and effective in the literature as an alternative to a second open thoracotomy/surgical repair. In our series, although in two cases, it represented a valid alternative to surgery. We suggest that it is worthy to try a conservative approach before surgery.

Awake Fiberoptic Intubation with Two Different Techniques of Local Anaesthetic Administration (Transtracheal Injection Versus Ultrasonic Nebulization) in Patients Undergoing Maxillofacial Surgery

Awake Fiberoptic Intubation with Two Different Techniques of Local Anaesthetic Administration (Transtracheal Injection Versus Ultrasonic Nebulization) in Patients Undergoing Maxillofacial Surgery

Minimally invasive transtracheal cardiac plexus block for sympathetic neuromodulation

Bilateral thoracoscopic stellectomy has antiarrhythmic effects, but the procedure is invasive with associated morbidity. Sympathetic nerves from both stellate ganglia form the deep cardiac plexus (CP) in the aortopulmonary window, anterior to the trachea. The purpose of this study was to demonstrate a novel and minimally invasive transtracheal approach to block the CP in porcine models. In 12 Yorkshire pigs, right (RSG) and left (LSG) stellate ganglia were electrically stimulated and sympathetic baseline response recorded (hemodynamic parameters and T-wave pattern). Aortopulmonary window was accessed transtracheally with endobronchial ultrasound guidance, and local stimulation of CP confirmed the location. Injection of 1% lidocaine (n = 10) or saline solution (n = 2) was performed, and RSG and LSG responses were re-evaluated and compared with baseline. Transtracheal lidocaine injection into the CP successfully blocked bilateral sympathetic induced changes (%) in T-wave amplitude (282.8% ± 152.2% vs 20.1% ± 16.5%; P <.001 [LSG]; 338.9% ± 189.8% vs 28% ± 18.3%; P <.001 [RSG]), Tp-Te interval (87.9% ± 37.2% vs 6.9% ± 6.7%; P <.001 [LSG]; 32.6% ± 27.4% vs 6.9% ± 4.7%; P <.035 [RSG]), and left ventricular dP/dTmax (148.3% ± 108.5% vs 16.5% ± 13.4%; P <.001 [LSG]; 243.1% ± 105.2% vs 19.0% ± 12.4%; P <.001 [RSG]). RSG-induced elevations of systemic, left ventricular, and pulmonary arterial pressures were blocked by lidocaine injection into CP (P <.005 for all comparisons). Stellate ganglia response was not affected in sham studies. No complications were observed during the procedures. Minimally invasive transtracheal injection of lidocaine into the CP blocked the sympathetic response of either RSG and LSG. Transtracheal assessment of CP may allow for minimally invasive and selective ablation of cardiac innervation, extending the cardiac sympathectomy denervation benefits to those not suitable for surgery.

Dynamic expression of transformating growth factor-β1 and caveolin-1 in the lung of Bleomycin-induced interstitial lung disease.

Interstitial lung disease (ILD) is a disease with high mortality worldwide. Unfortunately, its prognosis is still very poor. Therefore, developing the target molecular is very important for ILD diagnosis and treatment. Caveolin-1 (Cav-1) can regulate the formation of fibrosis by linking to the signaling pathway of transforming growth factor-β1 (TGF-β1), which is generally considered to be the most effective approach to solve the problem of ILD. The rat model of ILD was induced by disposable transtracheal injection of bleomycin hydrochloride. Rats were sacrificed in batches on days 7, 14, 21 and 28 after modeling, and the lung tissues was obtained for histopathological examination (HE) and Masson staining. Expressions of TGF-β1 and Cav-1 in the lungs were measured by western blot and real-time polymerase chain reaction (RT-PCR). Pulmonary inflammation was observed in lung tissue from day 7 after modeling; fibrosis was observed from day 14 after modeling; the collagen deposition reached the peak on day 21. Significant TGF-β1 up-regulation and Cav-1 down-regulation appeared in the inflammatory phase (7d); TGF-β1 expression level reached the peak and Cav-1 expression level reached the minimum on day 21-28 with the most obvious fibrosis. The rat model of bleomycin induced pulmonary fibrosis can be used to dynamically observe the progress of ILD. In the lung tissues from inflammation to fibrosis, TGF-β1 expression was significantly up-regulated and Cav-1 expression was significantly down-regulated. The regulation of two protein expressions is closely related to the occurrence and development of ILD in rats. The regulation of TGF-β1 and Cav-1 expressions and the balance between the two can be used as a possible target of ILD therapeutic intervention.

Efficacy of atomised local anaesthetic versus transtracheal topical anaesthesia for awake fibreoptic intubation.

Background and Aims:Successful awake fibreoptic intubation (AFOI) depends on adequate topical anaesthesia of the airway. We aimed to compare efficacy of atomised local anaesthetic versus transtracheal topical anaesthesia for AFOI.Methods:It was a prospective, randomised controlled study of 33 patients with the American Society of Anesthesiologists’ physical status 1–3 with anticipated difficult airway requiring AFOI. The primary objective was to compare the patient comfort after topical anaesthesia of the airway using atomiser with transtracheal injection of the local anaesthetic agent for AFOI in patients with anticipated difficult airway. The secondary objectives were to compare the ease of intubation, time required to intubate and the haemodynamic changes during intubation. After topical anaesthesia of nostrils, patients in Group T received transtracheal injection of 4 ml of 4% lignocaine whereas Group A patients received 4-5mL of 4% atomised lignocaine using DeVilbiss atomiser before AFOI. Patient comfort assessed objectively by the anaesthetic assistant during the procedure, ease of intubation assessed using cough and gag reflex score, time taken to intubate and the haemodynamic changes during the procedure were compared.Results:Ease of intubation, patient comfort and the time taken to intubate were significantly better in Group T patients, with P = 0.001, 0.009 and 0.019, respectively, compared with the patients in Group A. There were no significant changes in haemodynamic parameters.Conclusion:Topical anaesthesia by transtracheal injection in patients with anticipated difficult airway made AFOI easier and faster with better patient comfort compared to atomiser with no clinically significant untoward side effects.

Comparison of ultrasound and anatomical landmark-guided technique for superior laryngeal nerve block to aid awake fibre-optic intubation: A prospective randomised clinical study.

Background and Aims:Ultrasonography has emerged as a novel, portable, non-invasive tool encouraging airway assessment and procedural interventions. This study assesses the feasibility of ultrasound for block of internal branch of superior laryngeal nerve (ibSLN) block during upper airway anaesthesia to aid awake fibre-optic intubation.Methods:Forty American Society of Anesthesiologists’ physical status I–II patients, aged 18–60 years, deemed to have a difficult airway (modified Mallampati class III–IV or inter-incisor distance <2.5 cm) and planned for awake fibre-optic intubation were randomised to either landmark group (L, n = 20) or ultrasound group (U, n = 20). All patients received nebulised 4% lignocaine (3 mL) and transtracheal injection 3 mL 2% lignocaine. Group L received landmark-guided bilateral ibSLN block with 1 mL 2% lignocaine. Group U received bilateral ibSLN block with 1 mL 2% lignocaine using a high-frequency ultrasound transducer to define the SLN space. The primary objective was assessment of quality of airway anaesthesia. Secondary objectives were time for intubation, haemodynamic parameters and patient perception of discomfort during procedure.Results:The quality of anaesthesia was significantly better in Group U than in Group L (P < 0.001). The mean time for intubation was shorter in Group U (71.05 ± 9.57 s) compared to Group L (109.05 ± 30.09 s, P < 0.001). Heart rate, mean arterial pressure and patient perception of discomfort were significantly increased in Group L.Conclusion:Ultrasound for ibSLN block as a part of preparation for awake fibre-optic intubation improves quality of airway anaesthesia and patient tolerance.

Effectiveness of transtracheal lidocaine as an adjunct to general anesthesia in providing patient immobility during total parotidectomy: A comparison with dexmedetomidine infusion.

Backgroud and Aims:Dexmedetomidine and propofol infusions are increasingly being used to ensure intraoperative patient immobility in the absence of muscle relaxants during parotidectomy. The primary aim of our study was to assess the effectiveness of transtracheal block as an adjunct to general anesthesia in providing patient immobility during total parotidectomy, as compared to dexmedetomidine infusion.Material and Methods:This prospective, randomized study was conducted in 58 patients. Group A patients received a transtracheal injection of 4 ml of 4% lidocaine before induction whereas in Group B, dexmedetomidine 1 mcg/kg was administered intravenously. Following induction and intubation, anesthesia was maintained with oxygen, nitrous oxide, and isoflurane and dexmedetomidine was administered in Group B at a rate of 0.7 mcg/kg/h. In both the groups, if the patient moved, bucked, or if there were signs of inadequate depth of anesthesia, plane of anesthesia was deepened with a bolus of propofol 0.5 mg/kg intravenously. Mann–Whitney U-test and Fisher's exact test were used for statistical analysis.Results:The number of patients who moved in the transtracheal group was significantly less as compared to dexmedetomidine group (3 vs. 11). Mean heart rates (HRs) were comparable in both groups till 10 min, but between 15 and 180 min, Group B had significantly low HR. Systolic blood pressure (SBP) was significantly high at 10 min following dexmedetomidine bolus in Group B. Though Group B showed low SBP values as compared to Group A from 10 min following induction, the difference became significant between 45 and 180 min. Changes in mean arterial blood pressures followed a similar trend as with SBP.Conclusion:Transtracheal lidocaine ensured patient immobility with hemodynamic stability during total parotidectomy with nerve stimulation studies as compared to intraoperative dexmedetomidine infusion.

Awake Intubation with Video Laryngoscope and Fiberoptic Bronchoscope in Difficult Airway Patients

In a randomized clinical trial, Rosenstock et al.1 showed no significant difference in time to awake intubation by experienced investigators using the McGrath video laryngoscope (MVL) compared with the fiberoptic bronchoscope (FOB) in difficult airway patients. Accordingly, the authors conclude that awake MVL intubation seems to be a potential alternative to awake fiberoptic intubation. However, an important issue ignored by them is that awake intubation actually includes two parts: airway topical anesthesia and subsequent intubation.2 Moreover, effective airway topical anesthesia is a prerequisite to successfully perform awake intubation.3 When adequate airway topical anesthesia is obtained, subsequent intubation is usually easy. To obtain a uniform airway topical anesthesia in the two groups, transtracheal injection of lidocaine was used in this study. This method is invasive and carries more potential risk than other topical anesthesia methods do. More importantly, it can be difficult or even impossible to perform if the patient’s neck anatomy is troublesome to locate.4 In this study, a total of seven patients were excluded because transtracheal injection was impossible.In our view, a limitation of this study design is lack of assessment on the performance of airway topical anesthesia provided by the two devices. As a “gold standard” tool in managing difficult airway, FOB is not only a common choice for awake intubation, but can also provide flexibility in selectively anesthetizing the airway by a “spray as you go” technique.5 That is, two parts of the awake intubation can be completed with an FOB. In the Discussion section, the authors claim, “Awake MVL intubation may not prove as easy in using the ‘spray as you go’ technique, because insertion of the MVL blade causes pressure on the tongue and on the laryngeal structures, thereby probably creating a greater degree of patient discomfort compared with introducing the FOB.” It would be interesting to know whether there is any evidence to support the above comments. Had the authors performed airway topical anesthesia with the MVL?The MVL has an anatomically shaped blade with an extra curve, and oropharyngeal tissues do not need to be retracted and compressed to achieve a straight line of sight during laryngoscopy with the MVL.6 Thus, there is usually no need for significant lifting force to visualize the glottis. It has been shown that the use of Glidescope video laryngoscope with an anatomically shaped blade creates less pressure on the tongue when compared with the Macintosh blade.7,8 After topical anesthesia of the tongue and pharynx with lidocaine spray, patients can well tolerate the MVL with minimal discomfort.9 In our experience, once the oropharyngeal mucosa is anesthetized by the method described in this study, the MVL can be advanced easily to a position in the hypopharynx where the epiglottis and larynx can be clearly visualized. At this point, aliquots of lidocaine can be sprayed using a MADgic® atomizer (Wolfe Tory Medical Inc., Salt Lake City, UT). The MADgic® atomizer is then advanced through the glottis into the larynx and trachea to spray further aliquots of lidocaine in the remaining airway. This modified spray-as-you-go technique with the video laryngoscope can provide excellent airway topical anesthesia and is less affected by secretions or blood compared with fibreoptic technique. It has been used successfully in difficult airway patients who undergo awake intubation with Glidescope video laryngoscope.10 All of these suggest that performing airway topical anesthesia under superior vision of the airway with a video laryngoscope on awake subjects is feasible. Unfortunately, there has been no randomized clinical study comparing video laryngoscopic and fiberoptic techniques of airway topical anesthesia. Before we have enough evidence to make a conclusion that the video laryngoscope is a useful alternative to the FOB for awake intubation, therefore, further studies are needed to evaluate and compare performances of both airway topical anesthesia and awake intubation in difficult airway patients. In such a study, other than the intubation time and success rate, the observed variables should also include the patient’s comfort during airway topical anesthesia and awake intubation, time required for airway topical anesthesia, awake intubating condition, possible difficulties and so forth.2,5

Fiberoptic versus Videolaryngoscopic Management of the Difficult Airway: Problems with Postrandomization Patient Exclusion

We read with interest the recent article by Rosenstock et al.1 comparing the success of fiberoptic versus videolaryngoscopic intubation in patients with difficult airways. In that study, the authors conclude that there are no important differences between the two techniques. However, we are concerned by the postrandomization exclusion of a large number of patients from the analysis (9 of 93). In addition, there was a striking imbalance between the groups in the number of excluded patients (2 of 45 from the fiberoptic group and 7 of 48 from the videolaryngoscopy group). These exclusions have the potential for biasing or distorting the conclusions of the study.It is unclear why a number of these patients (i.e., the seven in whom a transtracheal injection was impossible) were enrolled in the study. It presumably would have been possible, based on a physical examination, to identify these patients before the randomization. In addition, the authors do not provide any a priori criteria for postrandomization exclusion, leaving open the possibility that the decision to exclude was left in the hands of the study providers at the time of the case—a potentially serious cause of exclusion bias. However, regardless of these issues, intention-to-treat rules demand that, because these nine patients were enrolled, randomized, and studied, they must somehow be included in the analyses; they cannot simply be discarded.We appreciate the problems of analyzing data when the experiment was difficult or impossible to complete as planned. There is, however, an established literature on dealing with missing data,2–4 and there are many different approaches depending on the nature of the data and the situation. The authors’ primary outcome was time to successful placement of the endotracheal tube. They might assign the shortest observed intubation time (which, from table 3, seems to be 20 s) to all nine excluded patients and rerun the analysis. Alternatively (and perhaps preferably), they might assign the longest possible intubation time (678 s) to all of the excluded patients. For an “extreme case analysis,” they could assign the shortest time to the excluded patients in one group and the longest time to the excluded patients in the other (and vice versa). Adding two patients with an intubation time of 20 s to the fiberoptic group and seven patients with an intubation time of 678 s to the laryngoscopy group would almost certainly result in a “significant difference” between groups. We agree that this may be too extreme given the large amount of missing data,5 but it points out the possibility that simply excluding patients from the analysis can confound the results. Conversely, if these various analyses result in a conclusion similar to the original (i.e., that there are no significant differences), then we can be reasonably comfortable that the missing data have not biased the results.The authors should also include these patients in their secondary outcome analyses, for example, number of attempts. In the authors’ table 3, they report the distribution of the number of attempts to secure the airway (one, two, or three attempts). They report a P value of 0.64 and conclude that there were no differences. However, this does not include the nine excluded patients. It would be reasonable to classify these as “failures” and add them to the analysis: two failures in the fiberoptic group and seven failures in the laryngoscopy group. When this is done, the P value (Fisher exact test) for the comparison decreases to 0.34. If one models a study with twice as many patients (assuming the same distribution of numbers of attempts and the same fraction of failures), the P values approach to 0.05—suggesting the possibility that the study was simply underpowered to detect an important difference between the two techniques.We do not wish to imply that these issues invalidate the authors’ work. But at the least, the possible impact of postrandomization exclusions should be discussed as an important limitation of the study and its potential influence on the outcome acknowledged. In addition, it reinforces the absolute necessity of abiding to intention-to-treat rules.

Awake intubation with video-assisted laryngoscope or intubating stylet

For anesthesiologists, it is inevitable to confront with various difficult conditions during mask ventilation and intubation. Therefore, anesthesiologists perform a variety of airway examinations and history taking to anticipate and to overcome demanding situations. Yet, the parameters obtained from such measurements are not satisfactory. In patients having the conditions that indicate difficult intubation, awake intubation is performed especially when the plausibility of mask ventilation is uncertain. Awake fiberoptic intubation has been adopted for management of anticipated difficult tracheal intubation. However, fiberoptic bronchoscope requires higher cost and longer time to learn the technique. Recently, laryngoscope or stylet with video system is used in various situations, including difficult intubation. Also, in awake intubation, some cases with video-assisted laryngoscope have been reported. Successful awake video-assisted laryngoscopic intubation has been performed in patients with limited neck extention and Mallampati grade 4 [1]. Also, Park et al. [2] reported a case of a patient with restricted mouth opening, nearly fixed neck movement and regressed mandible due to scar contracture where intubation was performed with the use of fiberoptic bronchoscopy under GlideScope® video laryngoscope guidance. Recently, Rosenstock reported that in 93 patients with an anticipated difficult intubation, there is no difference in patients' discomfort, ease of the technique and intubation success rate on the first attempt between the awake video-assisted laryngoscopic intubation and awake fiberoptic intubation [3]. Case reports with awake intubation using video-assisted intubating stylet are still rare. There is a case report that reported successful awake intubation with video-assisted intubating stylet in a patient with fixed neck due to halo vest and limited mouth opening (3 cm), in addition to modified Mallampati score grade 4 [4]. Smaller diameter of video-assisted intubating stylet can be applied to patients with more limited mouth opening or loose tooth than video-assisted laryngoscope. Video-assisted intubating stylet provided faster and easier intubations than the video-assisted laryngoscope in patients with limited neck motion [5]. In oral, laryngeal, glottic, supraglottic cancer, cancer bleeding during intubation procedure often interfere with the laryngoscopic view. In such situation, owing to smaller volume than video laryngoscope, the video-assisted intubating stylet is helpful to avoid injuring the mass and to overcome potentially traumatic airway manipulation. Patient preparation for awake intubation with video-assisted laryngoscope or intubating stylet is same as the preparation of awake fiberoptic intubation: antisialogue, oxygen supplement, topical application and transtracheal injection of local anesthetics. For adequate sedation and analgesia, combination of short acting opioids (eg. remifentanil) and sedatives (eg. propofol, or midazolam) infusion can be administered intravenously. Video-assisted laryngoscope or video-assisted stylet has an external monitor, and the supervisor can see the anatomy together and educate intubation skills on a case-by-case basis. With sufficient training of stylet usage, the quick and easy to use new instrument, such as video-assisted stylet, is expected to be selected as an alternative awake intubating device instead of the flexible fiberscope that requires longer time to learn. However, the currently used video-assisted laryngoscope and intubating stylet do not have the suction function. Therefore, preparations to prevent oral secretion are more important, and the assistant should help the oral suction of secretion or bleeding. In this respect, it is required to develop video-assisted laryngoscope or intubating stylet with the suction function in the near future.

Transtracheal lidocaine injection reduces the anesthetic requirements in brachial plexus surgeries

Aim:The purpose of this study was to evaluate the efficacy of transtracheal lidocaine injection to reduce the anesthetic requirements in patients who underwent brachial plexus surgery under general anesthesia.Settings and Design:This was a prospective randomized controlled study conducted in 40 consecutive adult patients.Materials and Methods:The patients were randomly allotted to two groups of 20 patients each. Group A patients received a transtracheal injection of 4 ml of 2% lidocaine before induction of anesthesia and group B patients did not receive it. The two groups were compared in terms of intraoperative propofol requirements and hemodynamic parameters.Statistical Analysis Used:Statistical analysis was done using Student's t-test for independent samples.Results:The propofol requirements were significantly less in group A in terms of the number of intraoperative events requiring propofol bolus at various time intervals in 3 h duration (4 vs. 77), the number of patients requiring propofol bolus injections (2 vs. 20), propofol infusion (0 vs. 20), and total propofol requirement (6 vs. 377 mg). After induction, patients in group B showed a statistically significant high heart rate, systolic blood pressure, and mean arterial pressure.Conclusion:The present study showed that the group of patients who received transtracheal block with lidocaine had a reduction in the requirement of the induction agent, propofol, and were more stable hemodynamically in the intraoperative period compared to those patients who did not receive transtracheal lidocaine. We conclude that transtracheal injection of lidocaine performed just prior to induction of general anesthesia is an effective alternative to intraoperative propofol infusion when long-acting muscle relaxants are to be avoided.

Awake Fiberoptic Intubation and Self-positioning in Patients at Risk of Secondary Cervical Injury

This study was designed to document the feasibility of self-positioning after awake fiberoptic intubation of the trachea using primarily effective topical anesthesia rather than sedation. We investigated 14 patients (ASA physical status 1 to 3) with a neurosurgical diagnosis of cervical instability or at risk of secondary cervical injury, who were scheduled for awake fiberoptic intubation and self-positioning prone. Topical anesthesia was accomplished using an oropharyngeal spray of lidocaine alone or in combination with a transtracheal injection of lidocaine for awake fiberoptic intubation and self-positioning prone. Patients evidencing anxiolysis were given midazolam 2 to 4 mg, i.v.. We assessed the need for sedation, tolerance of the endotracheal tube, patient comfort, incidence of coughing or gagging, and changes in heart rate, blood pressure, and oxygen saturation. In addition, patients were interviewed on the first postoperative day and asked to categorize the experience of awake intubation and positioning as a positive, neutral, or negative experience, or to have no recall. Eleven of the 14 patients turned themselves prone after awake fiberoptic intubation. No additional sedation was necessary for accomplishing positioning. Whereas 50% of the patients (7/14) showed mostly slight coughing or gagging during fiberoptic intubation, none of the patients who were positioned awake had coughing or gagging during tube fixation and prone positioning. The technique was unsuccessful in 3 patients. None of the patients viewed this as a negative experience. Our study demonstrates that awake fiberoptic intubation and patient self-positioning was feasible in this sample of patients at risk of secondary cervical injury. This technique may extend the opportunity of continuous neurological monitoring in patients with a risk of position-related cervical injury, especially where electrophysiological monitoring is not possible or is unavailable.

Awake Fiberoptic or Awake Video Laryngoscopic Tracheal Intubation in Patients with Anticipated Difficult Airway Management

Awake flexible fiberoptic intubation (FFI) is the gold standard for management of anticipated difficult tracheal intubation. The purpose of this study was to compare awake FFI to awake McGrath® video laryngoscope, (MVL), (Aircraft Medical, Edinburgh, Scotland, United Kingdom) intubation in patients with an anticipated difficult intubation. The authors examined the hypothesis that MVL intubation would be faster than FFI. Ninety-three adult patients with anticipated difficult intubation were randomly allocated to awake FFI or awake MVL, patients were given glycopyrrolate, nasal oxygen, topical lidocaine orally, and a transtracheal injection of 100 mg lidocaine. Remifentanil infusion was administered intravenously to a Ramsay sedation score of 2-4. Time to tracheal intubation was recorded by independent assessors. The authors also recorded intubation success on the first attempt, investigators' evaluation of ease of the technique, and patients reported intubation-discomfort evaluated on a visual analog scale. Eighty-four patients were eligible for analysis. Time to tracheal intubation was median [interquartile range, IQR] 80 s [IQR 58-117] with FFI and 62 s [IQR 55-109] with MVL (P = 0.17). Intubation success on the first attempt was 79% versus 71% for FFI and MVL, respectively. The median visual analog scale score for ease of intubation was 2 (IQR 1-4) versus 1 (IQR 1-6) for FFI and MVL, respectively. The median visual analog scale score for patients' assessment of discomfort for both techniques was 2, FFI (IQR 0-3), MVL (IQR 0-4). The authors found no difference in time to tracheal intubation between awake FFI and awake MVL intubation performed by experienced anesthesiologists in patients with anticipated difficult airway.

Docetaxel plus trans-tracheal injection of adenoviral-mediated p53 versus docetaxel alone in patients with previously treated non-small-cell lung cancer

This phase II clinical trial compared the efficacy and safety of two types of treatment in patients with non-small-cell lung cancer (NSCLC) who had previously been treated with chemotherapy. Patients diagnosed with NSCLC (with either measurable or evaluable lesions) and had been treated with chemotherapy were eligible for this study. They were randomly assigned to two groups. The DOCp53 group received trans-tracheal Adp53 injection (1 × 10(12) vp dosage) on day 1 and day 8, as well as docetaxel at 75 mg m(-2) on day 2. The DOC group only received docetaxel at 75 mg m(-2) on day 1. Patients in each group received treatment for two cycles before reevaluation. Between February 2005 and December 2006, 40 patients were recruited for this study. In all, 19 of them were assigned to the DOCp53 group and 21 were assigned to the DOC group. After a mean follow-up of 12 months, the median survival time (MST) was 7.7 months (95% CI, 4.53 to 10.84) for patients in the DOCp53 group and 5.9 months (95% CI, 4.11 to 7.68) in the DOC group (P = 0.44, log-rank test). In the DOCp53 group, two patients with diffuse metastatic disease of lung had partial response (PR) in addition to eight with stable disease (SD). No PR and 13 SD were observed in the DOC group. Toxic reactions that could be attributed to the Adp53 vector were transient fever and limited hemoptysis. For patients with relapsed NSCLC, trans-tracheal injection of Adp53 in addition to docetaxel did not improve overall survival or efficacy. However, direct trans-tracheal injection of Adp53 proved to be a safe procedure, with tolerable levels of toxicity.