Evaluation of tracheal intubation difficulty in patients with cervical spine immobilization: fiberoptic (WuScope) versus conventional laryngoscopy.
BACKGROUND: The WuScope is a rigid, fiberoptic laryngoscope designed to facilitate tracheal intubation without the need for head extension. The study evaluated the WuScope in anesthetized patients with neck immobilization. METHODS: Patients were randomized to one of two groups: those receiving fiberoptic laryngoscopy (WuScope, n = 43) and those receiving conventional laryngoscopy (Macintosh blade, n = 44). Manual in-line stablization of the cervical spine was done during intubation. Seven parameters of intubation difficulty were measured (providing an intubation difficulty scale score): number of operators, number of attempts, number of techniques, Cormack view, lifting force, laryngeal pressure, and vocal cord position. RESULTS: Successful intubation occurred in 95% of patients in the fiberoptic group and in 93% of patients in the conventional group. There were no differences in number of attempts. In the fiberoptic group, 79% of patients had an intubation difficulty scale score of 0, representing an ideal intubation: that is, one performed by the first operator on the first attempt using the first technique with full glottic visualization. Only 18% of patients in the conventional group had an intubation difficulty scale score of 0 (P < 0.001). More patients had Cormack grade 3 or 4 views with conventional than with fiberoptic laryngoscopy (39 vs. 2%, P < 0.001). Intubation times in patients with one attempt were slightly longer in the fiberoptic (median, 25th-75th percentiles: 30, 23-53 s) compared with the conventional group (24, 17-30 s, P < 0.05). Corresponding times in patients requiring > one attempt were 155 (range, 112-201) s and 141 (range, 95-186) s in the fiberoptic and conventional groups, respectively (P value not significant). CONCLUSIONS: Compared with conventional laryngoscopy, tracheal intubation using the fiberoptic laryngoscope was associated with lower intubation difficulty scale scores and better views of the laryngeal aperture in patients with cervical imnmobilization. However, there were no differences in success rates or number of intubation attempts. (+info)
Angled telescopic surgery, an approach for laryngeal diagnosis and surgery without suspension.
CONTEXT: Many methods have been used successfully for the diagnosis and treatment of laryngeal diseases. Microscopic and, recently, telescopic surgery represent the state of the art in endoscopic laryngeal surgery but drawbacks are possible during their application. To keep the suspension apparatus adequately positioned, excessive force is sometimes placed on the upper teeth and tongue with the laryngoscope tube causing damage. Complications in relation to the pharynx, larynx and cardiovascular system have also been reported. OBJECTIVE: In order to reduce complications resulting from the manipulation or stimulation of the upper aerodigestive tract and from torque forces on the upper teeth. We present a method of larynx surgery in which laryngeal suspension is not required. DESIGN: Technical report. TECHNIQUES: We have devised a fiber-optic telescope with its 40mm distal portion deviated 60 degrees from the direction of the proximal portion. This angle was taken by measuring patients immediately before standard microlaryngeal surgery was performed. The surgical instruments have the same angle as the telescope, in order to work on the larynx. This technique provides an image that is not limited by the distal aperture of the laryngoscope and has an advantage in that magnification and illumination may be provided by changing the distance of the lesion from the tip of the instrument. we have operated on four patients with laryngeal diseases and have had no complications as a result of this approach. We feel that this technique gives us the freedom to view the lesions better and helps to minimize the drawbacks caused by laryngeal suspension. (+info)
A method of endotracheal intubation and pulmonary functional assessment for repeated studies in mice.
The ability to successfully intubate the trachea of mice and control their ventilation is important for longitudinal studies requiring recovery from anesthesia and repeated pulmonary function measurements or other evaluations, such as the use of radiological imaging (e.g., computed tomography or magnetic resonance imaging). We describe a method for rapid and repeated intubation of mice, with subsequent pulmonary function measurements at baseline and after an agonist challenge. We describe a simply constructed metal blade used as a laryngoscope to facilitate oropharyngeal exposure, transillumination of the neck to facilitate visualization of the trachea through the oropharynx, readily available polyethylene tubing to intubate the trachea, and a simple solenoid ventilator to maintain physiological ventilation and assess respiratory resistance and compliance. Brief infusions of acetylcholine through a needle into the jugular vein are used to assess the responsiveness of the airway smooth muscle. (+info)
Supralaryngeal tubeless combined high-frequency jet ventilation for laser surgery of the larynx and trachea.
We have developed a new technique of combined high-frequency jet ventilation (HFJV), characterized by simultaneous application of a low-frequency (LF) and a high-frequency (HF) jet stream. Tubeless supralaryngeal jet ventilation was delivered via a modified Kleinsasser laryngoscope. We studied 44 adults undergoing 45 elective surgical procedures of the larynx and trachea using a carbon dioxide laser during HFJV. Applied inspiratory oxygen ratios ranged from 0.4 to 1.0. Mean driving pressures of the HF and LF jet streams were 1.5 bar and 1.8 bar in adults, respectively. Mean duration of HFJV was 41 (range 10-180) min. HFJV resulted in mean PaO2 and PaCO2 values of 16.6 (range 9.8-26.9) kPa and 5.7 (3.0-7.6) kPa, respectively. Tubeless supralaryngeal HFJV was safe and effective in maintaining gas exchange in the presence of laryngeal or tracheal stenoses, providing optimal visibility of anatomical structures, offering maximum space for surgical manipulation, and avoiding the use of combustible material inside the larynx or trachea. (+info)
Balloon laryngoscopy reduces head extension and blade leverage in patients with potential cervical spine injury.
BACKGROUND: Head extension and excessive laryngoscope blade levering motion (LBLM) are undesirable during airway management of trauma patients. We hypothesized that laryngoscopy with a modified blade facilitating glottic exposure by balloon inflation would reduce head extension and LBLM. PATIENTS AND METHODS: Seventeen elective surgery patients were enrolled. Patients lay supine with their heads flat on a rigid board and had a rigid collar around their necks. Laryngoscopy was performed with the modified blade and a standard curved blade. Head extension and LBLM angles were determined upon maximal glottic exposure and compared used paired t-tests. Laryngoscopic view grade and oxygen saturation were also determined. RESULTS: Balloon laryngoscopy resulted in less head extension and LBLM (P <0.001). Laryngoscopic view was approximately identical with both blades, and oxygen saturation was always above 97%. CONCLUSIONS: Balloon laryngoscopy reduces head extension and LBLM under simulated cervical spine precautions. (+info)
Use of angulated video-intubation laryngoscope in children undergoing manual in-line neck stabilization.
Laryngeal views obtained during direct laryngoscopy with and without manual in-line neck stabilization (MILNS) and during video-assisted intubation with MILNS using the angulated video-intubation laryngoscope were assessed in 100 paediatric patients (aged 0.25-17.3 yr). Visualization of the larynx (Cormack and Lehane score) as well as time taken for video-assisted tracheal intubation by six nurses and four resident anaesthetists not experienced in the technique were recorded. Cormack and Lehane scores were significantly worse during direct laryngoscopy when MILNS was applied. Video-assisted visualization of the larynx during MILNS produced scores, which were as good or better than those observed during direct laryngoscopy alone. Intubation times ranged from 19-75 s (mean 35 (SD 13.4); median 32). (+info)
Decontamination of laryngoscopes in The Netherlands.
In this study the decontamination procedures of laryngoscopes in Dutch hospitals are described, based on a structured telephone questionnaire. There were substantial differences between decontamination procedures in Dutch hospitals and the standards of the APIC (Association of Professionals in Infection Control and Epidemiology), CDC (Centers of Disease Control) and ASA (American Society of Anesthesiology) were met in full in 19.4% of the hospitals. The standards of manual decontamination, used in 78% of the 139 hospitals, were particularly disappointing; manual cleaning was considered inadequate in 22.9% of these hospitals and manual disinfection did not meet the standards of the APIC, CDC or ASA in any of these hospitals. Decontamination by instrument cleaning machines as a standard procedure was used in 30 (22%) hospitals. In three of these hospitals the blades were subsequently sterilized. We suggest adherence to the infection control guidelines of the CDC, APIC and ASA, until the safety of less conservative infection control practices are demonstrated. (+info)
Randomized evaluation of the performance of single-use laryngoscopes in simulated easy and difficult intubation.
BACKGROUND: Single-use laryngoscopes are becoming used more widely. METHODS: We compared six types of single-use laryngoscope with the standard Macintosh laryngoscope using the Laerdal SimMan patient simulator. Twenty anaesthetists attempted to intubate the simulator with standardized airway settings allowing a full view of the vocal cords ('easy intubation'). The airway settings were then changed so that only the posterior part of the glottis was visible ('difficult intubation') and the anaesthetists were asked to intubate the simulator again. RESULTS: The time to intubate with the standard laryngoscope was less in both easy (P<0.05) and difficult (P<0.01) intubations. The performance of five laryngoscopes during easy intubation (P<0.01) and four during difficult intubation (P<0.001) was significantly worse than that of the Macintosh. There was a significant difference in Cormack and Lehane grading between the laryngoscopes tested in both easy (P<0.05) and difficult (P<0.05) intubation. The percentage of glottic opening visible (POGO score) also differed between laryngoscopes in both the easy (P<0.01) and difficult (P<0.001) groups. The highest POGO scores were obtained with the Macintosh laryngoscope. During the difficult intubation simulation, the reusable Macintosh laryngoscope needed less use of a bougie and had fewer failed intubations than the single-use laryngoscopes, but these differences did not reach statistical significance. CONCLUSIONS: Of the laryngoscopes tested, the standard reusable Macintosh laryngoscope performed best. The Europa was the best single-use laryngoscope. Some single-use laryngoscopes tested were significantly inferior to the Macintosh. This raises concern over their use in clinical practice, particularly if intubation is difficult. (+info)