Framework for Indirect Spatial Calibration of the Horizontal Plane of Endoscopic Laryngeal Images

OBJECTIVE

Calibrated horizontal-plane measurements from laryngeal images could contribute significantly to refining evidence-based practice and developing patient-specific models and precision-medicine approaches. Laser-projection endoscopes can address the need for direct calibrated measures; however, these systems are not widely available. This study presents the framework for an alternative indirect horizontal-plane calibration approach.

METHOD

A spatial attribute of a common object, a distinct characteristic that is maintained across images, may be used as a scale for the normalization of other spatial measurements. The outcome of this indirect approach could be used for absolute measurements (eg, in units of mm) or relative measurements (eg, percent change), depending on the information that is available from the common attribute. The required conditions of a common attribute for achieving a valid calibration outcome were studied. Three conditions were derived: registration accuracy of the common attribute, size consistency of the common attribute, and similarity in the vertical distance between the region of interest (ROI) (eg, vocal fold) and the common attribute. Any common attribute satisfying these three conditions was called proper and would result in a valid indirect calibration outcome. Three tests were presented for evaluating the properness of a common attribute. A data-driven statistical method was presented that can evaluate the registration accuracy of a common attribute. The second test used variation in calibrated lengths of a common attribute under different phonatory configurations for evaluating the size consistency condition. Finally, the effect of differences between vertical distances of the ROI and the common attribute was mathematically tested and quantified. The application of the proposed framework for indirect calibration was demonstrated using a pre existing dataset with a vocal fold as the ROI and four different common attributes (vocal fold length, vocal fold width, blood vessel on the vocal fold, and blood vessel on nearby tissue).

RESULTS

The proposed registration-accuracy test was able to detect and eliminate instances of common attributes with low accuracies. The analysis suggested that among the studied four common attributes, the vocal fold length had the highest (ie, best) registration accuracy; however, the vocal fold length exhibited the lowest (ie, worst) size consistency. The analysis also suggested that, among the studied attributes, the vocal fold width offered the best trade-off among the three conditions and, hence, was a proper common attribute for calibrating spatial aspects of the vocal folds (length, displacement of edges, velocity, etc).

CONCLUSION

Indirect calibration is a feasible alternative for calibration of laryngeal endoscopic images, given a proper common attribute is selected. Future work is needed to systematically evaluate the effects of various phonatory conditions on the characteristics of common attributes.

Application of a Modified Endoscopy Face Mask for Flexible Laryngoscopy During the COVID-19 Pandemic

Diagnostic flexible laryngoscopy (DFL) is a critical tool in the armamentarium of an otolaryngologist. However, in the midst of the COVID-19 pandemic, DFL represents a high-risk procedure for patients and otolaryngologists due to the risk of aerosolization. In cases where DFL is required, in patients with COVID-19 positivity or unknown COVID-19 status, we describe the use of a modified endoscopy face mask as an adjunct to personal protection equipment to reduce occupational transmission of COVID-19 while performing DFL. Our modified endoscopy mask provides an additional barrier against the transmission of airborne pathogens. The modified endoscopy face mask may also serve as a useful tool for otolaryngologists as they return to performing more aerosol-generating procedures in the outpatient setting.

Assessment of Airway Parameters for Predicting Difficult Laryngoscopy and Intubation in a Tertiary Center in Western Nepal

BACKGROUND

The screening tests used for pre-operative evaluation of airway to predict difficult laryngoscopy and intubation have variable diagnostic accuracy. The unanticipated poor laryngeal view is gold standard for defining difficult intubation. We aimed to find out the prevalence of difficult laryngoscopy and intubation, which airway parameter better predicts difficult intubation and whether difficult laryngoscopy is associated with difficult intubation or not.

METHODS

This analytic cross sectional study was conducted in 665 ASA I/II adult patients, aged 18-65, without obvious airway pathology undergoing elective surgery under general anesthesia. The pre-operative screening tests included mouth opening, modified mallampatti, ratio of height to thyromental distance, sternomentaldistance and upper lip bite test. Cormack-Lehane grade III/ IV was defined as difficult laryngoscopy and potentially difficult intubation. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy and area under curve at 95% confidence interval was calculated for all five screening tests.

RESULTS

The prevalence of difficult laryngoscopy and intubation was 6.6% (44 cases). The upper lip bite test because of its highest specificity, positive predictive value, negative predictive value, accuracy and area under curve (99.7%; 93.9%; 99.7%; 95.2%; 85.1% respectively) with moderate level of sensitivity (70.5%) was better predictor of difficult intubation than other tests. The difficult laryngoscopy was associated with difficult intubation (p=0.00).

CONCLUSIONS

The prevalence of difficult laryngoscopy and intubation was 6.6%.The upper lip bite test was a better predictor of difficult intubation and there was a significant association of difficult laryngoscopy with difficult intubation.

Cervical Spine Motion During Tracheal Intubation Using an Optiscope Versus the McGrath Videolaryngoscope in Patients With Simulated Cervical Immobilization: A Prospective Randomized Crossover Study

BACKGROUND

In patients with an unstable cervical spine, maintenance of cervical immobilization during tracheal intubation is important. In McGrath videolaryngoscopic intubation, lifting of the blade to raise the epiglottis is needed to visualize the glottis, but in patients with an unstable cervical spine, this can cause cervical spine movement. By contrast, the Optiscope, a rigid video-stylet, does not require raising of the epiglottis during tracheal intubation. We therefore hypothesized that the Optiscope would produce less cervical spine movement than the McGrath videolaryngoscope during tracheal intubation. The aim of this study was to compare the Optiscope with the McGrath videolaryngoscope with respect to cervical spine motion during intubation in patients with simulated cervical immobilization.

METHODS

The primary outcome of the study was the extent of cervical spine motion at the occiput-C1, C1-C2, and C2-C5 segments. In this randomized crossover study, the cervical spine angle was measured before and during tracheal intubation using either the Optiscope or the McGrath videolaryngoscope in 21 patients with simulated cervical immobilization. Cervical spine motion was defined as the change in angle at each cervical segment during tracheal intubation.

RESULTS

There was significantly less cervical spine motion at the occiput-C1 segment using the Optiscope rather than the McGrath videolaryngoscope (mean [98.33% CI]: 4.7° [2.4-7.0] vs 10.4° [8.1-12.7]; mean difference [98.33% CI]: -5.7° [-7.5 to -3.9]). There were also fewer cervical spinal motions at the C1-C2 and C2-C5 segments using the Optiscope (mean difference versus the McGrath videolaryngoscope [98.33% CI]: -2.4° [-3.7 to -1.2]) and -3.7° [-5.9 to -1.4], respectively).

CONCLUSIONS

The Optiscope produces less cervical spine motion than the McGrath videolaryngoscope during tracheal intubation of patients with simulated cervical immobilization.

Recommended Protocols for Instrumental Assessment of Voice: American Speech-Language-Hearing Association Expert Panel to Develop a Protocol for Instrumental Assessment of Vocal Function

PURPOSE

The aim of this study was to recommend protocols for instrumental assessment of voice production in the areas of laryngeal endoscopic imaging, acoustic analyses, and aerodynamic procedures, which will (a) improve the evidence for voice assessment measures, (b) enable valid comparisons of assessment results within and across clients and facilities, and (c) facilitate the evaluation of treatment efficacy.

METHOD

Existing evidence was combined with expert consensus in areas with a lack of evidence. In addition, a survey of clinicians and a peer review of an initial version of the protocol via VoiceServe and the American Speech-Language-Hearing Association's Special Interest Group 3 (Voice and Voice Disorders) Community were used to create the recommendations for the final protocols.

RESULTS

The protocols include recommendations regarding technical specifications for data acquisition, voice and speech tasks, analysis methods, and reporting of results for instrumental evaluation of voice production in the areas of laryngeal endoscopic imaging, acoustics, and aerodynamics.

CONCLUSION

The recommended protocols for instrumental assessment of voice using laryngeal endoscopic imaging, acoustic, and aerodynamic methods will enable clinicians and researchers to collect a uniform set of valid and reliable measures that can be compared across assessments, clients, and facilities.

Failure to achieve first attempt success at intubation using video laryngoscopy is associated with increased complications

The purpose of this investigation was to investigate the association between first attempt success and intubation-related complications in the Intensive Care Unit after the widespread adoption of video laryngoscopy. We further sought to characterize and identify the predictors of complications that occur despite first attempt success. This was a prospective observational study of consecutive intubations performed with video laryngoscopy at an academic medical Intensive Care Unit. Operator, procedural, and complication data were collected. Multivariable logistic regression was used to examine the relationship between the intubation attempts and the occurrence of one or more complications. A total of 905 patients were intubated using a video laryngoscope. First attempt success occurred in 739 (81.7 %), whereas >1 attempt was needed in 166 (18.3 %). One or more complications occurred in 146 (19.8 %) of those intubated on the first attempt versus 107 (64.5 %, p < 0.001) of those requiring more than one attempt. Logistic regression analysis shows that >1 attempt is associated with 6.4 (95 % CI 4.4-9.3) times the adjusted odds of at least one complication. Pre-intubation predictors of at least one complication despite first attempt success include vomit or edema in the airway as well as the presence of hypoxemia or hypotension. There are increased odds of complications with even a second attempt at intubation in the Intensive Care Unit. Complications occur frequently despite a successful first attempt, and as such, the goal of airway management should not be simply first attempt success, but instead first attempt success without complications.

Cross-over study of novice intubators performing endotracheal intubation in an upright versus supine position

There are a number of potential physical advantages to performing orotracheal intubation in an upright position. The objective of this study was to measure the success of intubation of a simulated patient in an upright versus supine position by novice intubators after brief training. This was a cross-over design study in which learners (medical students, physician assistant students, and paramedic students) intubated mannequins in both a supine (head of the bed at 0°) and upright (head of bed elevated at 45°) position. The primary outcome of interest was successful intubation of the trachea. Secondary outcomes included log time to intubation, Cormack-Lehane view obtained, Percent of Glottic Opening score, provider assessment of difficulty, and overall provider satisfaction with the position. There were a total of 126 participants: 34 medical students, 84 physician assistant students, and 8 paramedic students. Successful tracheal intubation was achieved in 114 supine attempts (90.5 %) and 123 upright attempts (97.6 %; P = 0.283). Upright positioning was associated with significantly faster log time to intubation, higher likelihood of achieving Grade I Cormack-Lehane view, higher Percent of Glottic Opening score, lower perceived difficulty, and higher provider satisfaction. A subset of 74 participants had no previous intubation training or experience. For these providers, there was a non-significant trend toward improved intubation success with upright positioning vs supine positioning (98.6 % vs. 87.8 %, P = 0.283). For all secondary outcomes in this group, upright positioning significantly outperformed supine positioning.

Hands-Off Time for Endotracheal Intubation during CPR Is Not Altered by the Use of the C-MAC Video-Laryngoscope Compared to Conventional Direct Laryngoscopy. A Randomized Crossover Manikin Study

Introduction

Sufficient ventilation and oxygenation through proper airway management is essential in patients undergoing cardio-pulmonary resuscitation (CPR). Although widely discussed, securing the airway using an endotracheal tube is considered the standard of care. Endotracheal intubation may be challenging and causes prolonged interruption of chest compressions. Videolaryngoscopes have been introduced to better visualize the vocal cords and accelerate intubation, which makes endotracheal intubation much safer and may contribute to intubation success. Therefore, we aimed to compare hands-off time and intubation success of direct laryngoscopy with videolaryngoscopy (C-MAC, Karl Storz, Tuttlingen, Germany) in a randomized, cross-over manikin study.

Methods

Twenty-six anesthesia residents and twelve anesthesia consultants of the University Hospital Zurich were recruited through a voluntary enrolment. All participants performed endotracheal intubation using direct laryngoscopy and C-MAC in a random order during ongoing chest compressions. Participants were strictly advised to stop chest compression only if necessary.

Results

The median hands-off time was 1.9 seconds in direct laryngoscopy, compared to 3 seconds in the C-MAC group. In direct laryngoscopy 39 intubation attempts were recorded, resulting in an overall first intubation attempt success rate of 97%, compared to 38 intubation attempts and 100% overall first intubation attempt success rate in the C-MAC group.

Conclusion

As a conclusion, the results of our manikin-study demonstrate that video laryngoscopes might not be beneficial compared to conventional, direct laryngoscopy in easily accessible airways under CPR conditions and in experienced hands. The benefits of video laryngoscopes are of course more distinct in overcoming difficult airways, as it converts a potential “blind intubation” into an intubation under visual control.

What more can be done to popularize phonosurgical ideas in everyday handling of vocal folds?

This paper is focused on vocal fold surgery with phonosurgical intent. The aim of this review is to broaden phonosurgical knowledge, spread the ideas of the European Laryngological Society (ELS) on phonosurgery and translate the layered structure and physiology of the vocal fold described in Hirano's classic body-cover model into the graphic illustration of the "fluttering sleeve" created by Dikkers. In numerous countries, where phonosurgery is a relatively novel field of knowledge or still in its infancy, simple patterns and plain associations will serve the best in popularizing sophisticated vocal fold anatomy and preservation surgery and converting it into everyday routine.

Towards a basic endoscopic evaluation of swallowing in acute stroke - identification of salient findings by the inexperienced examiner

BACKGROUND

Dysphagia is common after stroke. Fiberoptic endoscopic evaluation of swallowing (FEES) is a powerful tool for dysphagia assessment. The purpose of this study was to assess whether a previously established endoscopic examination protocol based on the identification of typical findings indicative of stroke - related dysphagia may be learned and adopted by clinicians so far inexperienced in this field.

METHODS

After receiving a structured lecture on this topic, participants were asked to rate video sequences of endoscopic swallowing examinations of acute stroke patients. The first part of the testing ("single findings-rating") comprised of 16 single sequences, the second part ("complete examination-rating") presented the key sequences of 8 complete examinations. Before the second part was started, results of the first were discussed.

RESULTS

At the "single findings-rating" 88.8% of video-sequences were assessed correctly, while at the "complete examination-rating" the average performance had improved to 96%. Furthermore, no overlooking of relevant pathologies was noted in the second part of the testing.

CONCLUSION

This study suggests that the presented endoscopic examination protocol is reliably interpreted by inexperienced clinicians after a short lecture and may therefore easily and successfully be adopted in dysphagia management of acute stroke care.

[Correlation between laryngoscopic examination and the gastroesophagial reflux in dysphonic patient]

OBJECTIVES

The gastro-esophageal reflux disease is responsible of oto-rhino-laryngological symptoms included dysphonia. We studied the relationship between reflux disease and dysphonia. The research for the prevalence of reflux disease, in a dysphonic population, has been performed by a clinical and laryngoscopic survey.

METHODS

175 patients were included prospectively. Each patient replies to the questionnaire and see the physician to do a laryngoscopic examination during the same time. A physician jury sees all videos to determine gastro-oesophagial reflux disease laryngoscopic signs.

RESULTS

Statistically significant correlations were found for vocal oedema and posterior hypertrophia in relation with reflux.

CONCLUSION

We have pointed out that laryngoscopy is not an adequate diagnosis tool, because it is operator dependant. Nevertheless the diagnosis of gastro-esophageal reflux disease, regarding the vocal symptoms, is proposed when associated with clinic reflux signs (pyrosis).

User satisfaction and forces generated during laryngoscopy using disposable Miller blades: a manikin study

Increasing awareness of prion-related diseases has led to an increase in the number of disposable laryngoscope blades available. We compared 11 disposable and standard re-usable Miller size 1 blades. In this manikin-based study, we studied user satisfaction for field of view at laryngoscopy, build quality and users' willingness to use the blade in an emergency situation. These were found to be better with metal disposable blades (p</=0.001). Vertical and horizontal forces developed during laryngoscopy were greater with plastic than with metal blades.

Evolving concepts of laryngeal paralysis

Accepted concepts of the pathophysiology and treatment of laryngeal paralysis have changed over the years. It has long been observed that symptoms of laryngeal paralysis vary greatly, both between patients and over time. There have been various theories to explain these differences. This article reviews how these ideas have changed over time as research has produced new information. Currently, the most popular view is that the laryngeal nerve regenerates after injury, albeit incompletely and inconsistently, and that variations in symptoms and laryngeal posture can be accounted for by muscle activity.

Laryngoscopic versus intubating LMA guided tracheal intubation by novice users—A manikin study

AIM OF THE STUDY

Airway control is a potentially lifesaving procedure but tracheal intubation by direct laryngoscopy is difficult. This pilot study was conducted to determine whether tracheal intubation was more rapid and the success rate higher using an intubating laryngeal mask airway.

MATERIAL AND METHODS

The success rates of 119 medical students without prior airway management experience in ventilating and then intubating the trachea of a Laerdal Airway Management Trainer with two different methods were compared. The methods were bag-mask ventilation (BM-V) followed by laryngoscopic intubation (LG-TI), and intubating laryngeal mask ventilation (ILMA-V) followed by ILMA-guided tracheal intubation (ILMA-TI). After an introductory lecture and demonstration, each student was allowed three attempts to intubate using each method in random order.

RESULTS

All participants were successful with BM-V and ILMA-V on the first attempt. Laryngoscopic tracheal intubation was achieved by 60 (50.4%), 31 (26.1%) and 12 (10.1%) participants on the first, second and third attempt, respectively, while 16 (13.4%) failed in all three attempts. In the ILMA-TI group, 107 (90.0%), 10 (8.4%) and 2 (1.6%) succeeded on the first, second and third attempt, respectively. None failed. The intergroup difference is highly significant (p<0.001). Male participants were more successful with LG-TI than female (p<0.01), but not with ILMA-TI.

CONCLUSION

Laryngoscopic orotracheal intubation is difficult for the untrained, but all participants were successful with ILMA-TI. These data suggest that alternative devices such as the ILMA should be included in the medical school curriculum for airway management.

Retention of tracheal intubation skills by novice personnel: a comparison of the Airtraq�and Macintosh laryngoscopes

Direct laryngoscopic tracheal intubation is a potentially lifesaving manoeuvre, but it is a difficult skill to acquire and to maintain. These difficulties are exacerbated if the opportunities to utilise this skill are infrequent, and by the fact that the consequences of poorly performed intubation attempts may be severe. Novice users find the Airtraq laryngoscope easier to use than the conventional Macintosh laryngoscope. We therefore wished to determine whether novice users would have greater retention of intubation skills with the Airtraq rather than the Macintosh laryngoscope. Twenty medical students who had no prior airway management experience participated in this study. Following brief didactic instruction, each took turns performing laryngoscopy and intubation using the Macintosh and Airtraq devices in easy and simulated difficult laryngoscopy scenarios. The degree of success with each device, the time taken to perform intubation and the assistance required, and the potential for complications were then assessed. Six months later, the assessment process was repeated. No didactic instruction or practice attempts were provided on this latter occasion. Tracheal intubation skills declined markedly with both devices. However, the Airtraq continued to provide better intubating conditions, resulting in greater success of intubation, with fewer optimisation manoeuvres required, and reduced potential for dental trauma, particularly in the difficult laryngoscopy scenarios. The substantial decline in direct laryngoscopy skills over time emphasise the need for continued reinforcement of this complex skill.

Safety and cost-effectiveness of intra-office flexible videolaryngoscopy with transoral vocal fold injection in dysphagic patients

SETTING

A tertiary care referral-based otolaryngology practice.

OBJECTIVES

To evaluate the safety of office-based transoral oral vocal fold injection in an ambulatory dysphagic population and to evaluate cost-effectiveness in comparison with traditional injection laryngoplasty done under general anesthesia in the operating room. Dysphagia is a nonspecific and common symptom of many head and neck and systemic disease processes. In patients with glottal incompetence, the presenting complaint of dysphagia generally portends to more global oropharyngeal dysfunction than dysphonia alone. Although many authors have reported on and advocated the use of office injection technique in the management of dysphonia caused by glottal insufficiency, there is a paucity of literature regarding the use of this technique in a more medically compromised dysphagic patient population (Ann Otol Rhinol Laryngol 1997;106:778-83). We describe our experience with vocal fold injection in the office setting using a transoral technique under flexible videolaryngoscopy for the treatment of glottal insufficiency in dysphagic patients. The safety and cost-effectiveness of this approach are highlighted.

Use of condoms as blade covers during laryngoscopy, a method to reduce possible cross infection among patients

OBJECTIVES

Laryngoscope blades are in close contact with mucous membranes and can possibly contaminated with virulent or readily transmissible organisms. As laryngoscopy is often required during endotracheal intubation, proper cleaning and sterilization of the laryngoscope blade is crucial to prevent cross-contamination among patients.

METHODS

We tested the effectiveness of latex condom using as a laryngoscope blade cover during endotracheal intubation. Both control (no condom) and study group blades were rinsed with sterile saline after intubation. The rinse was sent for bacteria culture, and appearance of bacterial colonization was counted as positive. A water leak test (WLT) was performed on used condoms to verify their integrity.

RESULTS

There were total 162 laryngoscopes studied with 83 (51.2%) scopes in the study group and 79 (48.8%) in the control group. Rate of positive bacterial culture were 13.3% and 88.6% in the study and control group, respectively. Although WLT (+) rate of 41% was found in the study group, a high negative culture rate (71.6%) was also noted among the WLT (+) group.

CONCLUSIONS

Condom when using as a blade cover during laryngoscopy is a simple, inexpansive and effective way in reducing cross contamination among patients.

Minimum dataset for the recording of findings of flexible nasopharyngolaryngoscopy

A dataset for assessing and recording findings of flexible nasopharyngolaryngoscopy is proposed.

Rapid sequence intubation of trauma patients in Scotland

BACKGROUND

Endotracheal intubation remains the gold standard for trauma airway management. Rapid sequence intubation (RSI) has traditionally been performed by anesthesiologists but increasingly, emergency physicians are also undertaking RSI. We aimed to compare success and complication rates for trauma intubations for the two specialties.

METHODS

Two year, prospective multi-center descriptive study of trauma RSI in seven Scottish urban emergency departments.

RESULTS

439 trauma patients were identified, including 233 RSIs. Patients intubated by emergency physicians had a higher median ISS (p < 0.001) and lower median RTS (p < 0.001) compared with anesthesiologists. For RSI, anesthesiologists had more grade I & II views at laryngoscopy (p = 0.051) and more successful first attempt intubations (p = 0.034) but there was no difference in the number of patients suffering complications (emergency physicians 10.0%, anesthesiologists 10.6%).

CONCLUSION

There is no significant difference in complication rates for trauma RSI between emergency physicians and anesthesiologists in Scottish urban centers. A collaborative approach to the critical trauma airway is vital. Emergency physicians should consult with senior anesthesiologists before RSI when intubation is predicted to be difficult.

Compact endoscopy of the larynx

In order to improve preoperative assessment of suspected precancerous and cancerous lesions of the larynx, we examined 83 patients by compact endoscopy (combination of autofluorescence and contact endoscopy) during microlaryngoscopy in a pilot study. The intraoperative findings were related to histopathologic examination. Cancerous laryngeal mucosa was illuminated during autofluorescence endoscopy by use of blue filtered light (D-light AF system) for optical demarcation of the lesion. After staining the mucosa with methylene blue (1%), we performed contact endoscopy. During autofluorescence examination of the endolaryngeal mucosa, the appearance of precancerous and cancerous lesions varied between opaque light areas and darker reddish areas. By contact endoscopy, it was possible to observe the cells, nuclei, and cytoplasm, as well as different degrees of abnormality. Histopathologic findings of 83 patients revealed laryngeal dysplasia (grade I in 29 patients, grade II in 15, and grade III or carcinoma in situ in 8) and laryngeal cancer (31 patients). In 73 cases (88%), the findings of compact endoscopy corresponded to those of histopathology. In 5 cases, epithelial lesions were overestimated because of inflammation and scarring, and 5 cases were underestimated because of hyperkeratotic thickening of the mucosa covering basal epithelial layers with focal dysplasia of grades II and III, carcinoma in situ, and microinvasive cancer. We conclude that compact endoscopy enables the laryngologist to assess laryngeal cancer and its preceding lesions more accurately during microlaryngoscopy.

[The relevance of mirror examination in modern otorhinolaryngology]

INTRODUCTION

The aim of this study was to investigate whether the teaching of mirror examination of the larynx and rhinopharynx is still relevant and to estimate whether it is still a reliable examination.

MATERIAL AND METHOD

Twenty-five patients underwent a mirror examination of the larynx and rhinopharynx by a young doctor, a young otorhinolaryngologist, and a senior otorhinolaryngologist.

RESULTS

Not surprisingly the senior otorhinolaryngologist conducted the most adequate examinations. Forty-three percent of the laryngoscopies were adequate, that is all anatomic structures were seen. Forty-one per cent provided a reasonable survey, that is a few anatomic structures were not seen. This shows that 84% of the laryngoscopies could be used to give a reasonable examination of the larynx. Only 27% of the rhinoscopies were completely adequate, and as many as 49% were inadequate.

DISCUSSION

Routine mirror examination of the larynx adequately provides a reliable diagnosis in most patients. But in some, it is not adequate, and here fibrolaryngoscopy is a good alternative and a more reliable examination. Mirror examination of the rhinopharynx is difficult, so if a disease of the rhinopharynx is suspected, the patient must be given a fibroscopy and biopsy under general anaesthesia.

Contact endoscopy of the larynx: a quantitative study

Contact endoscopy is a technique of obtaining detailed magnified images of living epithelium, using a modified glass rod lens endoscope placed on the surface of the tissue. The technique has been extensively described in gynaecological, and more recently, laryngeal and nasal tissues. However, no quantitative studies of its diagnostic accuracy yet exist. A prospective partially blinded controlled study of eight cases with a variety of laryngeal pathologies is described. A single pathologist with no knowledge of the ultimate histological diagnoses successfully identified six of eight laryngeal pathologies on contact endoscopic findings, while the other two cases were identified to a degree of accuracy that was sufficient to positively identify the need for standard tissue biopsy. The advantages and disadvantages of the technique are described, along with suggestions for its role in clinical practice.

An assessment of the luminance and light field characteristics of used direct laryngoscopes

PURPOSE

To determine luminance and light field characteristics and the effect of residual battery potential and luminance on light colour temperature in our used Macintosh #3 and #4 fibre-light (FLB) and bulb-light (BLB) laryngoscopes.

METHODS

We used a power supply to provide laryngoscopes with potentials equivalent to those most commonly measured in the handles in use in our OR. Measurements were made under controlled, constant, conditions using a Pentax digital spotmeter (luminance) or a Minolta Color III colour temperature meter (light colour). Colour measurements were made while increasing the power source potential from 2-3 volts (v) in increments of 0.1 v. Light field measurements were made with a mm increment ruler mounted on the base of the test fixture.

RESULTS

At 2.5 and 2.8 v respectively, the #3 FLB produced luminance values of 23.9 +/- 11.4 and 41.7 +/- 17.2 cd x m(-2) (mean +/- SD), and the #4 FLB produced 58.6 +/- 21.4 and 90.9 +/- 32.2 cd x m(-2). Increasing potential increased luminance values (P < 0.001) and the #4FLB produced higher luminance values (P < 0.001). BLB produced higher luminance values than did FLB across all comparisons (P < 0.001). As potentials and luminance values decreased, light temperature was reduced (P < 0.001). There were no differences in light field dimensions noted in any comparison.

CONCLUSION

Fifteen percent of the BLB did not meet the minimum luminance for laryngoscopy of 100 cd x m(-2), 92% of the FLB did not meet that same standard.

Endotracheal intubation

Endotracheal intubation can be accomplished by several different methods, which are discussed herein. Special considerations such as the obstructed tube, air leakage around the tube, tube replacement, and drug therapy are also reviewed, as are the indications for tracheostomy, the use of double lumen tubes, and fiberoptic laryngoscopy or bronchoscopy.

B-mode real-time ultrasound assessment of vocal cord function in recurrent laryngeal nerve palsy

B-mode real-time ultrasound was used to assess vocal cord function in six patients with recurrent laryngeal nerve palsy. The thyroid cartilage acted as an acoustic window through which the true cords appear as hypoechoic structures. Vocal cord palsy detected on ultrasound was compared with fibreoptic direct laryngoscopy and indirect laryngoscopy mirror examination. Good correlation was seen in all the cases.

Laryngeal pathologies observed in microlaryngoscopy

A retrospective analysis of 738 consecutive microlaryngoscopic procedures, performed in 655 patients at the Geneva Clinic of Otolaryngology, Head and Neck Surgery between 1981 and 1987, was undertaken. The 4 most frequent laryngeal pathologies were polyps, hyperplastic chronic laryngitis, Reinke's edema and laryngeal cancer accounting for 76.6% of all encountered pathologies. Of the sample studied, pathologies occurred more frequently in males than in females; however, certain pathologies were more common to one sex than to the other. In 15.3% of patients with benign lesions, multiple, coexisting laryngeal diseases were detected. In some instances, microlaryngoscopic and histological diagnoses were discordant.

[Chronic laryngitis and carcinoma (author's transl)]

35 cases of continuous series of 841 laryngeal cancers were studied separately. Those patients had already been suffering from hoarseness for more than 2 years, in the average for 9 years. Many of these patients had been examined and treated by inhalations, and biopsies were taken because of a chronic laryngitis. Clinically in half of the cases a big carcinoma could be found. In 10 cases a chronic laryngitis had been diagnosed; in spite of the preceeding examination by microlaryngoscopy in 4 cases, however, the carcinoma could only be proved by histologic examination. The histologic examinations of the specimens regularly displayed an extended field of epidermisation of the laryngeal mucosa following chronic laryngitis, In these fields of epidermisation the carcinoma developed multicentrically and--in the early stages--mostly showed a covering-like, minutely infiltrating growth. Disseminated dot-like cancer-focuses in the epidermisation field and cancer buds arising from the basal layers of an intact covering of the hypertrophic epithelium could be observed several times. Chronic-hypertrophic laryngitis seems to favour the development of cancer within some patients (promoting factor), it even might accelerate it. As in about 6% of all the vocal cord cancers a preexistent chronic laryngitis is proved by history and clinical findings each patient with a chronic hypertrophic laryngitis must be examined by microlaryngoscopy as well as histological examinations and must be constantly observed.