Orthostatic hypotension with syncope--a problem of hypertensive therapy in the aged

STUDY OBJECTIVE: To assess the efficacy of the "laryngeal lift" maneuver in improving laryngoscopic visualization to facilitate endotracheal intubation. DESIGN: Blinded study. SETTING: Operating room at Meridia Huron Hospital. PATIENTS: 305 patients receiving general anesthesia for elective surgery requiring intubation. (Five patients were eliminated from the study because we elected to intubate these patients awake and sedated.) INTERVENTIONS: Following induction of anesthesia and paralysis with muscle relaxants, laryngoscopic views of each patient were evaluated by the laryngoscopist before and after the laryngeal lift was performed by an anesthesiologist assisting the laryngoscopist. Each patient served as his or her own control group. The anesthesiologist was blinded to the results obtained by the laryngoscopist. All Grade I laryngoscopic views were eliminated (198 patients). Five patients were eliminated on the basis of obesity or atlantoaxial subluxation. The laryngeal lift was performed on the remaining 102 patients, representing Grade II to Grade V laryngoscopic views. MEASUREMENTS AND MAIN RESULTS: A modification of the original classification of laryngoscopic views by Cormack and Lehane was used: Grade I = full view of glottis; Grade II = only posterior commissure visible; Grade III = arytenoids visible; Grade IV = epiglottis visible; Grade V = no glottic structure visible. In 98 of 102 cases (96%), the maneuver improved visualization by at least 1 grade. There was no evidence of change in the 4 remaining cases. CONCLUSIONS: The laryngeal lift should be part of the anesthesiologists' armamentarium in helping the laryngoscopist who is faced with Grades II, III, IV, and V laryngoscopic views to enhance visualization of the larynx and thus facilitate endotracheal intubation.     

A comparison between the Macintosh and the McCoy laryngoscope blades

The view of the larynx using the Macintosh laryngoscope and the McCoy levering laryngoscope was assessed in 177 adult patients. The view with the McCoy blade in the neutral position and in the position (neutral or elevated) that gave the 'best' view were recorded. The McCoy blade in the neutral position was associated with a lower incidence of grade 1 views and a higher incidence of grade 2 views than the Macintosh blade. There was no difference in the incidence of grade 3 views. When views for each patient using the different blades were compared, the McCoy blade in the neutral position produced a worse view than the Macintosh blade (p < 0.0001). The view obtained with the McCoy blade in its 'best' position and the Macintosh blade were similar. In the 152 patients in whom the vocal cords were seen using the Macintosh blade, the view was worse using the McCoy blade in its 'best' position more often than it was better (p = 0.06). In 25 patients, the vocal cords could not be seen with the Macintosh blade; in these patients the view was better with the McCoy blade (the cords were visible) on 14 occasions and worse in one (p = 0.001). We conclude that the McCoy blade in its neutral position does not behave identically to the Macintosh blade. The McCoy blade is a useful aid to difficult intubation but should not replace the Macintosh blade as the first choice laryngoscope.     

Behavioural topography in the striatum: differential effects of quinpirole and D-amphetamine microinjections

The structure of the nervous network and the distribution of tyrosine hydroxylase (TH)- and various neuropeptide-containing nerves were immunohistochemically studied in the glottis of the dog. The nervous network in the glottis revealed apparent regional differences in morphology. The nervous network in the cartilaginous vocal fold of the posterior glottis consisted of nerve bundles running parallel to the edge of the vocal fold. Only a small number of nerve bundles were observed in the anterior glottis, specifically in membranous vocal fold. In the subepithelial layer of the posterior glottis, a moderate number of galanin (GAL)-immunoreactive nerve fibers were observed, while only a few fibers were present in the anterior glottis. Numerous vasoactive intestinal peptide (VIP)-, GAL-, methionine-enkephalin (ENK)- and TH-immunoreactive nerve fibers were observed within and around the laryngeal submucosal seromucous gland. Many TH- and neuropeptide Y (NPY)-immunoreactive fibers were arranged around the blood vessels. In the epithelia, free nerve endings with immunoreactivity for substance P (SP) and calcitonin gene-related peptide (CGRP) was observed. Furthermore, nerve cell bodies with SP-, VIP-, GAL-, ENK-, and NPY-immunoreactivity were observed in the deep region of the submucosal layer. The results from the present study suggest that there is autonomic regulation of the glottis. Regional structural differences in the nervous network of the glottis may reflect functional differences.     

Skin vasomotor reflex induced by laryngoscopy: comparison of the McCoy and Macintosh blades

We studied 22 female patients (ASA I or II) to investigate if laryngoscopy and intubation induced the skin vasomotor reflex (SVmR), and to compare the effects of the McCoy and Macintosh blades on the SVmR. Anaesthesia was induced with fentanyl, midazolam, vecuronium and nitrous oxide. In 11 patients, the vocal cords were seen for 3 s with the McCoy blade. Two minutes later, laryngoscopy was performed with the Macintosh blade and the trachea was intubated. In the other 11 patients, the first and second laryngoscopies, respectively, were performed with the Macintosh and McCoy blades. Laryngoscopy alone and intubation with laryngoscopy significantly reduced skin blood flow in the ring finger of all patients (P < 0.01), indicating that both procedures provoked the SVmR. The magnitude of the SVmR and haemodynamic changes did not differ significantly between the two groups.     

Sexually transmitted disease among married Zambian women: the role of male and female sexual behaviour in prevention and management

Two methods of endotracheal intubation of patients lying on the ground were compared for ease and speed of intubation and minimization of complications in a crossover study of prehospital-oriented emergency physicians. Intubation of a mannequin was attempted by the physicians in either a left lateral decubitus (LLD) position or a kneeling (K) position, followed by the alternate position. The LLD position afforded more rapid intubation, better glottic visualization, and less dental trauma. Eighty-seven percent of physicians completely visualized the glottis in the LLD position, versus 33% of the K position group. Intubation times were 10.5 versus 14.6 seconds in the LLD and K positions, respectively (P < .001). The LLD position is a more effective position (in a mannequin model) than the K position for intubation of patients found lying on the ground, a frequent situation in prehospital care.     

Further studies of phonation threshold pressure in a physical model of the vocal fold mucosa

This paper reports results of further experimentation on a previously developed physical model of the vocal-fold mucosa [Titze et al., J. Acoust. Soc. Am. 97, 3080-3084 (1995)]. The effects of vocal-fold thickness, epithelial membrane thickness, and prephonatory glottal geometry on phonation threshold pressure were studied. Phonation threshold pressures in the range of 0.13 to 0.34 kPa were observed for an 11-mm-thick vocal fold with a 70-micron-thick "epithelial" membrane for different "mucosal" fluid viscosities. Higher threshold pressure was always obtained for thinner vocal folds and thicker membranes. In another set of experiments, lowest offset threshold pressure was obtained for a rectangular or a near-rectangular prephonatory glottis (with a glottal convergence angle within about +/- 3 degrees). It ranged from 0.07 to 0.23 kPa for different glottal half-widths between 2.0 and 6.0 mm. The threshold for more convergent or divergent glottal geometries was consistently higher. This finding only partially agrees with previous analytical work which predicts a lowest threshold for a divergent glottis. The discrepancy between theory and data is likely to be associated with flow separation from a divergent glottis.     

Effect of the signal measured from the glottis on determination of the vocal tract shape

All-pole and pole-zero models for the vocal tract are developed. First an impulse train, then the pressure signal measured from the glottis, is used as the input in the models. The models for eight Turkish vowels produced by one male subject are studied to determine the effects of the presumed impulse train and the pressure signal measured from the glottis on the estimation of the vocal tract shape. The motion of the tongue is also examined for a whole word.     

Recurrent laryngeal nerve paralysis after thyroid gland operations. Etiology and consequences]

In the period of 1 January 1990 to 31 December 1996 the thyroidectomy cases we performed were immediately followed by vocal cord evaluation using a flexible bronchoscope while the patient was still on the operating table. If an obvious cord paralysis was discovered, an exploration of the recurrent laryngeal nerve, to the level of the larynx, was performed. If the nerve was found to be intact, no further measures were taken. A severed nerve underwent suture repair. If an otolaryngologist diagnosed a vocal cord paralysis 1-5 days after surgery, a reoperation was recommended except in the cases where postoperative bronchoscopy had shown an easily mobile cord or the recurrent nerve was completely dissected during the operation. Within this 7-year period, we performed 3492 thyroidectomy operations. The diagnosis of subsequent unilateral postoperative vocal cord paralysis occurred in 48 cases. In 33 of these cases the status of the nerve in the surgical field was known: 4 patients had an intact nerve proved by complete dissection during thyroidectomy, in two patients the lesions of the nerve were detected intraoperatively (1 transsection, 1 partial resection), and 27 cases were followed by reoperation. Of the 33 patients mentioned above, in 19 instances the recurrent laryngeal nerve was found to be intact; 3 displayed signs of local trauma, and 11 were found to be severed with total discontinuity. Those patients with an intact nerve, or local nerve trauma only, went on to develop normal function within 6 months in 20 (91%) of 22 cases. Of the 11 with a severed nerve, 8 showed "autoparalysis" with good voice within 4-8 months, after suture repair in 10 cases. The patient with partial resection had no repair of the nerve. If immediate postoperative evaluation showed mobility of the vocal cords but a paralysis was detected later by an otolaryngologist and repeat intervention was not done, vocal cord function was spontaneously restored in 9 of 11 patients. Four patients refused reoperation. From 1990 to 1991, the recurrent laryngeal nerve was not always dissected during our thyroidectomy operations. However, this was done routinely from 1991 to 1996. Routine intraoperative dissection of the vocal cord nerve reduced the rate of postoperative cord paralysis from 2.0% to 1.2%. It also reduced the frequency of intraoperative nerve injury with total discontinuity from 0.58% to 0.23%.     

Nucleotide sequencing analysis of the 146-kilobase segment around the IkBL and MICA genes at the centromeric end of the HLA class I region

The biomechanics of medialization laryngoplasty are not well understood. An excised canine larynx model was used to test the effects of various sized silicon implants. The vocal fold length, position, and tension were measured. Medialization laryngoplasty did not affect vocal fold length. At the mid-membranous vocal fold, larger shims resulted in greater medialization and tension. Medialization laryngoplasty neither medialized nor stiffened the vocal process to resist lateralizing forces. We conclude that medialization laryngoplasty provides bulk and support for defects of the membranous region of the vocal fold, but does not appear to close a posterior glottal gap. The selection of a surgical procedure to treat glottal incompetence should take into account the unique biomechanical properties of the anterior (membranous vocal folds) and posterior (cartilaginous portion) glottis.     

Acute acromegalic dyspnea

A case of acute "acromegalic dyspnea" due to vocal cord fixation and subglottic mucosal hypertrophy is reported. The patient was treated by intubation, tracheostomy, stereotactic implantation of radioisotopes 192Ir and 198Au via the transsphenoidal route.     

Difficult tracheal intubation with von Recklinghausen disease

We experienced a case of difficult tracheal intubation in a 15-year-old boy with von Recklinghausen disease scheduled for resection of a right neck tumor. His scoliosis made it difficult to intubate and to manage airway because he easily developed dyspnea. We tried nasotracheal intubation with the patient awake under sedation using a bronchofiberscope, but we found an unexpected tumor jeopardizing his airway patency near his vocal cord. Preoperative examination of a tumor in the airway is essential in the anesthetic management of the patients with von Recklinghausen disease.     

An endolaryngeal method of vertico-lateral transposition of the vocal cord for bilateral abductor paralysis

An endolaryngeal method of vertico-lateral elevation and fixation of the vocal fold in the treatment of bilateral recurrent laryngeal nerve paralysis is described. In 62 patients on whom this operative procedure was performed, a considerable improvement in respiration at the same time as almost unchanged phonation has been obtained in 61 cases. The results are illustrated by sonograms and respirometric examinations. Laryngograms demonstrate the function of the newly created glottis.     

Familial occurrence of temporal arteritis

The incidence of difficulty in tracheal intubation in the presence of goiter was investigated. Data were collected in a series of 4742 consecutive adult patients undergoing general anesthesia. The prevalence of goiter was 6.8%. Fifteen anesthesiologists performed the preoperative airway assessment using standardized guidelines. Seven individual risk factors were correlated with the potential for difficult tracheal intubation. Whenever evidence of goiter or airway pathology was observed, the evaluation was completed by indirect laryngoscopy and radiologic examination to establish the presence of any anatomical deviation. Difficult intubation was defined as inadequate exposure of the glottis by direct laryngoscopy. There was no difference in probability of difficulty in tracheal intubation between patients who presented for thyroidectomy and patients with goiter estimated as a random finding. Statistical analysis revealed an increased risk of difficult intubation amongst goiter patients compared with patients with no evidence of any risk factor (6.8% vs 0.9%, P < 10(-8), relative risk = 7.4). We conclude that goiter, when accompanied by airway deformity, constitutes an aggravating factor for difficult intubation.     

Using the bubble inclinometer to measure laryngeal tilt and predict difficulty of laryngoscopy

STUDY OBJECTIVE: To evaluate a simple device, the bubble inclinometer, to measure degrees of laryngeal tilt (LT) for predicting difficulty of direct laryngoscopy using a Macintosh #3 laryngoscope. DESIGN: Randomized, double-blind study. SETTING: Inpatient surgery center at a university medical center. PATIENTS: 50 renal lithotripter patients. INTERVENTIONS: Patients were measured with the bubble inclinometer and the laryngeal indices caliper. A sleep dose of thiopental sodium (4 mg/kg) and a muscle-relaxing dose of succinylcholine (1 mg/kg) were then given to each patient. MEASUREMENTS AND MAIN RESULTS: LT was measured by both methods (directly and indirectly). Difficulty of laryngoscopy was graded as follows: Grade 1 = all of vocal cords seen; Grade 2 = part of vocal cords seen; Grade 3 = no part of vocal cords seen. CONCLUSIONS: The bubble inclinometer accurately and reproducibly measures relative LT, and the anterior tilt of the larynx directly correlates with the ability to see the laryngeal opening during direct laryngoscopy with a Macintosh #3 laryngoscope.     

An analysis-by-synthesis approach to the estimation of vocal cord polyp features

This paper deals with a new noninvasive method of estimating vocal cord polyp features through hoarse-voice analysis. A noteworthy feature of this method is that it enables us not only to discriminate hoarse voices caused by pathological vocal cords with a single golf-ball-like polyp from normal voices, but also to estimate polyp features such as the mass and dimension of polyp through the use of a novel model of pathological vocal cords which has been devised to simulate the subtle movement of the vocal cords. A synthetic hoarse voice produced with a hoarse-voice synthesizer is compared with a natural hoarse voice caused by the vocal cord polyp in terms of a distance measure and the polyp features are estimated by minimizing the distance measure. Some estimates of polyp dimension that have been obtained by applying this procedure to hoarse voices are found to compare favorably with actual polyp dimensions, demonstrating that the procedure is effective for estimating the features of golf-ball-like vocal cord polyps.     

Blood grouping of mixed bloodstains using immunocytochemical methods

Immunocytochemical methods to determine the ABO blood group of each blood of mixed bloodstains have been developed. Mixed bloodstains were made on surgical blades and a cedar board. The blades were dipped into blood and then dipped into blood of a different group at intervals of 30, 20, 15, 10 and 5 s. Two drops of blood were dropped on a cedar board and then two drops of blood of a different group were dropped there at the same intervals. The bloodstains were dried for a week. The blood samples were removed from the blades or the cedar board and processed according with a routine histological method. Three serial thin sections were obtained. After deparaffinization, the sections were treated in papain solution for 2 h at 36 degrees C, to unmask antigenic sites on red cell membranes. The labeled streptavidin-biotin (LSAB) and peroxidase-anti-peroxidase (PAP) methods were used to detect A and B antigens, and an indirect immunocytochemical method for H antigen. These immunocytochemical methods showed specific immunologic reactions and allowed determination of the blood group of each blood of mixed bloodstains. Further, these methods indicated a possibility to determine who was stabbed first, in cases where two or more victims were stabbed with a single knife.     

Children''s return to school after treatment for cancer: study days for teachers

We present a case of benign paradoxical vocal cord adduction' presenting to the emergency department as acute stridor. This patient received direct laryngoscopy at initial presentation documenting inspiratory vocal cord adduction. The syndrome is not well known to emergency physicians and, because it often mimics life-threatening airway compromise, prompt recognition of the benign nature of this syndrome may avert more aggressive airway interventions such as beta agonists, steroids, endotracheal intubation and tracheostomy. Successful treatment has included relaxation, sedatives and speech therapy to abort the acute attack and prevent further recurrence. As direct flexible laryngoscopy is more readily available in the emergency department, goals for the future are more rapid diagnosis and appropriate treatment of this benign syndrome.     

The use of the laryngeal mask in a female patient with an unpredictable difficult intubation

A laryngeal mask was used after repeated ineffective attempts at intubation. Preoperative examinations failed to defect signs of a possible difficult intubation. Laryngoscopy showed a true glottis, but it was impossible to insert tube No. 6 in the trachea. Failure of attempts at intubation made us use a laryngeal mask for maintaining the patency of the upper airways. Anesthesia coursed smoothly in the presence of stable hemodynamics and gas exchange. Use of laryngeal mask helped solve the problem of unpredictable difficult intubation and provide reliable patency of the upper respiratory airways in a female patient with latent stenosis of the subglottal space.     

Diagnostic value of tomography in unilateral vocal cord paralysis

Tomographic studies were made on 56 patients with unilateral paralysis of the vocal cord. The findings were examined in relation to etiology, course, and laryngoscopic findings. In 74.1 percent of the cases, marked enlargement of the ventricle was noticed on the side of the paralysis, especially during inhalation. The paralyzed vocal cord was higher than the intact cord during phonation in 46.4 percent of the cases. The rest of the cases (53.6 percent) demonstrated no level difference between the vocal cords. The position of the paralyzed vocal cord, unilateral involvement of the cricothyroid muscle and other neck muscles were suggested as possible contributors to the findings.     

Interphase cytogenetics for studying solid tumors

The authors report a rare case of bilateral vocal cord paralysis following anterior cervical discectomy and fusion (ACD/F) in a patient who had a preexisting, clinically silent, and unrecognized unilateral vocal cord paralysis from a remote cardiac surgical procedure. The patient, a 41-year-old woman who developed acute respiratory stridor and respiratory insufficiency at the time of extubation after undergoing a C6-7 ACD/F, required emergency reintubation and ventilation. Otolaryngological evaluation revealed bilateral vocal cord paralysis with one vocal cord showing evidence of acute paralysis and the other showing evidence of chronic paralysis. She eventually required a permanent tracheotomy. The patient had undergone previous cardiac surgical procedures to correct Fallot's tetralogy as a neonate and as a child. At those times, there were no recognized symptoms of transient or permanent vocal cord dysfunction. This case emphasizes the importance of identifying patients with preexisting unilateral vocal cord paralysis before performing neurosurgical procedures such as ACD/F, which can place the only functioning vocal cord at risk for paralysis. Guidelines for identifying patients with preexisting unilateral vocal cord paralysis and for modifying the surgical procedure for ACD/F to prevent the catastrophic complication of bilateral vocal cord paralysis are discussed.