Soham Roy

The benign lymphoepithelial cyst and a classification system for lymphocytic parotid gland enlargement in the pediatric HIV population

Objectives/Hypothesis: The objectives of this study are to present a series of parotid gland benign lymphoepithelial cysts (BLEC) in HIV‐positive children and to propose a three‐tiered classification system for HIV‐associated lymphocytic parotid gland enlargement.

Acoustic analysis of the singing and speaking voice in singing students.

The singing power ratio (SPR) is an objective means of quantifying the singers formant. SPR has been shown to differentiate trained singers from nonsingers and sung from spoken tones. This study was designed to evaluate SPR and acoustic parameters in singing students to determine if the singer-in-training has an identifiable difference between sung and spoken voices. Digital audio recordings were made of both sung and spoken vowel sounds in 55 singing students for acoustic analysis. SPR values were not significantly different between the sung and spoken samples. Shimmer and noise-to-harmonic ratio were significantly higher in spoken samples. SPR analysis may provide an objective tool for monitoring the students progress.

Operating room fires in otolaryngology: risk factors and prevention

PURPOSE The aim of the study was to characterize the causes of operating room (OR) fires in otolaryngology. MATERIALS AND METHODS A questionnaire was designed to elicit the characteristics of OR fires experienced by otolaryngologists. The survey was advertised to 8523 members of the American Academy of Otolaryngology-Head and Neck Surgery. RESULTS Three hundred forty-nine questionnaires were completed. Eighty-eight surgeons (25.2%) witnessed at least one OR fire in their career, 10 experienced 2 fires each, and 2 reported 5 fires each. Of 106 reported fires, details were available for 100. The most common ignition sources were an electrosurgical unit (59%), a laser (32%), and a light cord (7%). Twenty-seven percent of fires occurred during endoscopic airway surgery, 24% during oropharyngeal surgery, 23% during cutaneous or transcutaneous surgery of the head and neck, and 18% during tracheostomy; 7% were related to a light cord, and 1% was related to an anesthesia machine. Eighty-one percent of fires occurred while supplemental oxygen was in use. Common fuels included an endotracheal tube (31%), OR drapes/towels (18%), and flash fire (where no substrate burned) (11%). Less common fuels included alcohol-based preparation solution, gauze sponges, patients hair or skin, electrosurgical unit with retrofitted insulation over the tip, tracheostomy tube, tonsil sponge, suction tubing, a cottonoid pledget, and a red rubber catheter. CONCLUSIONS OR fire may occur in a wide variety of clinical settings; endoscopic airway surgery, oropharyngeal surgery, cutaneous surgery, and tracheostomy present the highest risk for otolaryngologists. Electrosurgical devices and lasers are the most likely to produce ignition.

Incidence of abnormal laryngeal findings in asymptomatic singing students

OBJECTIVE: Abnormalities in the mucosal lining of the vocal folds may interfere with the normal vibratory patterns and result in vocal limitations, especially for singers whose demands are great. A prospective, longitudinal study was undertaken to investigate the incidence of laryngeal abnormalities in asymptomatic singing students. METHODS: Sixty-five singing students at the school of music underwent videostroboscopic evaluation and completed a comprehensive questionnaire. Videos were rated by 3 experienced clinicians, and interrater reliability was calculated. Results were correlated with demographic factors, background medical history, and singing history. RESULTS: Five students (8.3%) exhibited early signs of benign vocal fold lesions (2 with nodules and 3 with cysts). A high incidence of posterior erythema (n = 44; 73.4%), suggesting possible reflux, was found. CONCLUSIONS: A surprisingly high number of otherwise asymptomatic singing students demonstrated abnormal laryngeal findings. Their relationship with vocal performance will be addressed as well as implications for preventative measures. (Otolaryngol Head Neck Surg 1999;121:69-77.)

What does it take to start an oropharyngeal fire? Oxygen requirements to start fires in the operating room☆

INTRODUCTION Airway fires are a well-described and potentially devastating complication of oropharyngeal surgery. However, the actual factors required to ignite the fire have never been well-delineated in the medical literature. In this study, we used a mechanical model to assess the oxygen parameters necessary to cause an oropharyngeal fire. METHODS An electrosurgical unit (Bovie) was grounded to a whole raw chicken and a 6.0 endotracheal tube (ETT) was inserted into the cranial end of the degutted central cavity. Oxygen (O(2)) was then titrated through the ETT tube at varying concentrations, with flow rates varying from 10 to 15L/min. Electrocautery (at a setting of 15W) was performed on tissue in the central cavity of the chicken near the ETT. All trials were repeated twice to ensure accuracy. Positive test results were quantified by the time required to obtain ignition of any part of the mechanical setup and time required to produce a sustained flame. A test was considered negative if no ignition could be obtained after four minutes of direct electrocautery. RESULTS At an O(2) concentration of 100% and a flow rate of 15L/min, ignition with a sustained flame was obtained between 15 and 30s after initiation of electrocautery. At 100% O(2) at 10L/min, ignition was obtained at 70s with immediate sustained flame. At an O(2) concentration of 60%, ignition occurred at 25s and sustained fire after 60s. At an O(2) concentration of 50% ignition with a sustained flame occurred between 128 and 184s. At an O(2) concentration of 45%, neither ignition nor sustained flames could be obtained in any trial. CONCLUSIONS Operating room fires remain a genuine danger when performing oropharyngeal surgery where electrocautery is performed in an oxygen-enriched environment. In our study, higher O(2) flow rates with higher FiO(2) correlated with quicker ignition in the chicken cavity. A fire was easily obtained when using 100% O(2); as the O(2) concentration decreases, longer exposure to electrocautery is required for ignition. Below 50% O(2) we were unable to obtain ignition. Our study is the first to examine the relative risk of ignition and sustained fire in a mechanical model of oropharyngeal surgery. Decreasing the fraction of inspired O(2) (FiO(2)) to less than 50% may substantially decrease the risk of airway fire during oropharyngeal surgery.

Bipolar radiofrequency plasma ablation (Coblation) of lymphatic malformations of the tongue

OBJECTIVE To describe the removal of lymphatic malformations of the tongue using bipolar radiofrequency plasma ablation. METHODS We report a retrospective case series at a tertiary care academic childrens hospital. Three children with lymphatic malformations of the tongue causing symptomatic pain, bleeding and difficulty eating were treated with bipolar radiofrequency plasma ablation (Coblation). Two children had previously undergone wide local excision, both of whom experienced rapid multifocal recurrences. Using the bipolar radiofrequency plasma ablation wand, each lymphatic malformation was ablated to the submucosal surface of the tongue. In all three children, healing occurred by secondary intention. RESULTS All three children were able to resume a regular diet and were discharged from the hospital by post-operative day 1. After a minimum 6 months follow-up, none of the lesions have recurred and none have required additional treatment. One child has a palpable scar in the central portion of the tongue, where the previous wide local excision had been closed with sutures. She remains asymptomatic without complaints. There were no complications in any child. CONCLUSIONS Bipolar radiofrequency plasma ablation (Coblation) may provide a safe, simple and effective technique for removal of lymphatic malformations of the tongue in children.

Fire/burn risk with electrosurgical devices and endoscopy fiberoptic cables.

PURPOSE The purpose of the study was to systematically explore the fire and burn risk associated with fiberoptic cables and electrosurgical devices. MATERIALS AND METHODS A 300-W light source was connected to a standard gray fiberoptic light cable. The end of the cable was either rested atop or buried within a cotton towel or polypropylene drape in the presence or absence of 100% oxygen for up to 10 minutes. A monopolar electrosurgical device set at 1 W, 10 W, or 30 W was tested on a cotton towel or polypropylene drape for a period of 30 seconds. All trials were repeated. RESULTS Resting the light cable on top of the cotton towel or polypropylene drape with or without oxygen produced no result. Burying the end of the cable within the drape produced a hole in the drape within 15 seconds both with and without oxygen. Burying the end of the cable within the cotton towel produced a yellow discoloration after 2 minutes both with and without oxygen. The monopolar electrosurgical device set at 30 W burned immediately through the polypropylene drape, producing a skin burn. All other trials with monopolar electrocautery produced no result. No flame or fire was produced in any trial. CONCLUSIONS Fiberoptic cables and electrosurgical generators represent a serious burn risk for surgical patients, with operating room drapes and towels affording only limited protection. Otolaryngologists should be keenly aware of the risks that these devices represent because our specialty uses them frequently.

Relationship between aerodynamic measures of glottal efficiency and stroboscopic findings in asymptomatic singing students

Singing requires exquisite coordination between the respiratory and phonatory systems to efficiently control glottal airflow. Asymptomatic singing students underwent pulmonary function testing (PFT), videostrobolaryngoscopic examination, and measures of glottal efficiency (maximum phonation time [MPT], glottal flow rate [GFR], and phonation quotient [PQ]) performed in both a sung and spoken tone. Pulmonary function and glottal efficiency values were within reported normative data for professional singers. However, sung tones were made with significantly higher GFR and PQ and lower PQ than spoken tones. The mean GFR was not related to the degree of glottal closure (by videostrobolaryngoscopy) or underlying pulmonary support.

Surgical Fires in Laser Laryngeal Surgery Are We Safe Enough

Objective Laser surgery of the larynx and airway remains high risk for the formation of operating room fire. Traditional methods of fire prevention have included use of “laser safe” tubes, inflation of a protective cuff with saline, and wet pledgets to protect the endotracheal tube from laser strikes. We tested a mechanical model of laser laryngeal surgery to evaluate the fire risk. Study Design Mechanical model. Setting Laboratory. Subjects and Methods An intubation mannequin was positioned for suspension microlaryngoscopy. A Laser-Shield II cuffed endotracheal tube was placed through the larynx and the cuff inflated using saline. Wet pledgets covered the inflated cuff. A CO2 laser created an inadvertent cuff strike at varying oxygen concentrations. Risk reduction measures were implemented to discern any notable change in the outcome after fire. Results At 100% FiO2 an immediate fire with sustained flame was created and at 40% FiO2 a near immediate sustained flame was created. At 29% FiO2, a small nonsustained flame was noted. At room air, no fire was created. There was no discernible difference in the severity of laryngeal damage after the fire occurred whether the tube was immediately pulled from the mannequin or if saline was poured down the airway as a first response. Conclusions While “laser safe” tubes provide a layer of protection against fires, they are not fire proof. Inadvertent cuff perforation may result in fire formation in low-level oxygen enriched environments. Placement of wet pledgets do not provide absolute protection. Endotracheal tube (ETT) cuffs should be placed distally well away from an inadvertent laser strike while maintaining the minimum supplemental oxygen necessary.

Applications for transoral robotic surgery in the pediatric airway

To report preliminary experience in the utilization of transoral robotic surgical (TORS) techniques in pediatric airway surgery.