The value of methylprednisolone in the treatment of an experimental sensorineural hearing loss following drill-induced ossicular chain injury: a randomized, blinded study in guinea-pigs.

In a previously established animal model a standardized drill-induced injury to the body of the incus was applied, and the effects on hearing were characterized by electrocochleography. In a placebo-controlled, randomized, blinded study methylprednisolone showed no protective effect in reducing or improving the auditory threshold shifts, which occurred within seconds after drilling and remained stable throughout the 5-week observation period. Therefore the otologic surgeon must pay close attention to avoiding any contact of a rotating burr with an ossicle in an intact ossicular chain.

Experimental sensorineural hearing loss following drill-induced ossicular chain injury.

In a guinea pig model, a standardized drill-induced injury to the body of the incus was applied, and the effects on hearing were characterized by electrocochleography. Drilling resulted in a threshold shift within seconds, and after 15 min it averaged 35.7 dB for clicks, 35 dB nHL for 4 kHz bursts, 36.7 dB nHL for 6 kHz bursts and 39 dB nHL for 8 kHz bursts. The deterioration of the threshold shift remained stable throughout the 5-week post-operative observation period. In five animals a disarticulation of the incudostapedial joint was performed prior to drilling, but this did not reduce the threshold shift. Caution is mandatory during drilling around an intact ossicular chain to avoid a permanent sensorineural hearing loss, and disarticulation of the incudostapedial joint prior to drilling has no protective value.

Endoscopic endonasal dacryocystorhinostomy: results in 56 patients.

Fifty-six patients with a complete stenosis of the nasolacrimal duct were treated by endoscopically controlled intranasal dacryocystorhinostomy according to West. Forty-four patients had idiopathic stenosis and 12 had posttraumatic scarring. Revision surgery was done in 11 of these 56 cases (8 patients with a previous external Toti procedure, and 3 patients with previous endonasal surgery). Altogether, 95% of the patients were symptom-free (86%) or felt improved (9%) postoperatively. Surgical revision was successful in 82%. Of patients with an "idiopathic" stenosis, 84% were healed and an additional 11% were improved. The success rate in the 12 patients with posttraumatic stenosis was 92%. Endoscopic duct surgery is a highly successful procedure with a low complication rate, the worst complication being persistence of symptoms.

Measurement of total respiratory impedance in infants by the forced oscillation technique.

The forced oscillation technique according to Làndsér et al. (J. Appl. Physiol. 41:101-106, 1976) was modified for use in infants. Adaptations, including a flexible tube to connect the infant to the measuring system and a bias flow to avoid rebreathing, did not influence impedance values. The linearity of the respiratory system was assessed and confirmed by 1) applying pseudo-random noise oscillations at three different amplitudes to 7 infants and 2) comparing in 12 infants impedance values obtained with pseudo-random noise and with sinusoidal oscillations at 12 and 32 Hz. Intersubject variability, averaged for all frequencies, was 6%. In 17 infants the relative error (+/- SD) between two series of five measurements within a time interval of 15 min was 0.5 +/- 5.7%. No statistically significant difference was found between impedance values before and after repositioning of the infant's head, whereas rotation resulted in a decrease in resistance and no effect on reactance. Our results indicate that the infant-adapted forced pseudo-random noise oscillation technique has the potential to give valuable information about ventilatory lung function in infants.

[Sensitivity and specificity of multi-frequency oscillation methods, body plethysmography and spirometry in 5-8-year-old asthmatic patients]. / Sensitivität und Spezifität von polyfrequenter Oszillationsmethode, Bodyplethysmographie und Spirometrie bei Asthmatikern im Alter von 5-8 Jahren.

We compared specificity and sensitivity of the forced oscillation technique with the standard methods of body plethysmography and spirometry in children suffering from asthma (age 5-8 yrs). We investigated 60 healthy and 66 asthmatic children by forced oscillation, plethysmography and spirometry. Mean FEV1% pred was 99.7 and 82.4% in the healthy and asthmatic subjects, respectively, and mean SRaw was 0.68 and 1.18 kPa*s, respectively. Forced oscillation and plethysmography could be measured in all children, whereas 29% of the investigated children failed to perform valid spirometry. Discriminant analysis was used to compare the optimal classification which could be obtained from the measured data with the clinical one. Fixing specificity to 95%, we computed sensitivities of 66% (forced oscillation), 68% (body plethysmography), and 76% (spirometry). We conclude that the diagnostic value of the three methods in young children with asthma is similar. However, the value of spirometry is limited by cooperation in these young children.

[Bioequivalence of theophylline retard capsules in children and relation of metabolism to administration route]. / Untersuchung zur Bioäquivalenz von Theophyllin-Retardkapseln bei Kindern und zur Abhängigkeit der Metabolisierung vom Applikationsweg.

The bio-availability of two slow-release theophylline capsules employing different sustained-release principles, was investigated in 12 children suffering from bronchial asthma, on this basis of the renal excretion of the unchanged active substance. With the aid of a model-bound convolution procedure, the completeness and the variability of absorption on multiple dosaging under non-steady-state conditions were established. Depending upon the retardation principle, both the mean bioavailability and its scatter differed from one preparation to the other, one of them being, on average, more completely absorbed than the other, while, at the same time, showing an appreciably more variable bio-availability. In consequence of the first pass metabolisation, the percentage of theophylline that was excreted unchanged in the urine, was greater with the intravenous route of administration than with peroral application. In the case of the secondary metabolite 3-methylxynthine, the situation was reversed.

[Impedance of the respiratory tract of healthy newborn infants--studies using the polyfrequency oscillation method]. / Die Impedanz des Respirationstraktes gesunder Neugeborener--Untersuchungen mit der polyfrequenten Oszillationsmethode.

Resistance and reactance of the respiratory tract of 40 healthy newborn were measured by means of the polyfrequent oscillation method. Mean resistance had frequency-dependent values between 20.91 and 9.63 cm H2O per litre per second and mean reactance between -29.11 and -3.81 cm H2O/1/s. The resistance--but not the reactance--was found to depend on the body length and the body weight of the infants.

Correspondence between forced oscillation and body plethysmography during bronchoprovocation with carbachol in children.

We compared dose-response curves obtained with the forced oscillation technique (FOT) and with body plethysmography during bronchoprovocation in children. In 40 stable asthmatic children (age, 5-16 yr) we performed challenges with doubling concentrations of inhaled carbachol (0.15-10 mg/mL) until specific airway resistance SRaw had increased by 100% (PC100SRaw). The FOT-response was assessed by total respiratory system resistance (Rrs, cmH2O.1(-1).s) and reactance (Xrs, cmH2O.1(-1).s) from 8 to 26 Hz, expressed as mean Rrs (Rrs), mean Xrs (Xrs), Rrs at 8 Hz (Rrs8), and mean slope of Rrs (dRrs/df). Dose-response curves were analyzed for threshold concentrations (TC) causing a 3 SD change from baseline and sensitivity indices (SI) defined as differences between baseline and postchallenge values (at PC100SRaw) divided by baseline SD. Median TC of Rrs8, Rrs, Xrs, dRrs/df, and SRaw was 0.21, 0.30, 0.34, 0.41, and 0.42 mg/mL, respectively, indicating a slightly higher sensitivity for FOT. Median SI values of SRaw and Xrs (12.0 and 8.2; difference n.s.) were significantly higher than those of the other parameters. Multiple regression analysis revealed only the absolute change of Xrs (delta Xrs), baseline Rrs and age as significantly (P less than 0.001) correlated with the percentage change of SRaw (delta %SRaw). Best correlation (r = 0.86) with delta %SRaw was found for the function: FOT score = -102.5 X delta Xrs X exp(-0.196 X Rrs + 0.038 X age). Provocative concentrations estimated by this FOT score differed from PC100SRaw by less than one (two) concentration steps in 34 (40) out of 40 children.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic value of body plethysmographic parameters in healthy and asthmatic young children is not influenced by breathing frequency.

In 16 healthy and 16 asymptomatic asthmatic children (age range 5-8 yr; 8 girls, 24 boys) we studied the influence of breathing frequency on the results and the diagnostic value of body plethysmographic measurements. Airway resistance (Raw), specific airway resistance (SRaw), and thoracic gas volume (TGV) were measured during breathing (or breathing efforts against a closed shutter) at 0.4, 1, and 2 Hz. SRaw was computed by a simplified procedure directly from flow at the mouth vs. box volume-curves. The diagnostic value of each parameter was assessed as the percentage of correctly classified healthy and asthmatic subjects by means of discriminant analysis. When frequency was increased from 0.4 to 1 and 2 Hz mean TGV rose by 5 and 14% in healthy children and by 11 and 21% in asthmatic children, respectively. From 0.4 to 1 Hz mean Raw decreased by 16% (P = 0.002) in healthy children and by 25% (P = 0.0004) in asthmatic children. The differences in Raw between both groups decreased with frequency (3.5, 1.8, and 1.5 cm H2O.L-1.s at 0.4, 1, and 2 Hz, respectively) and those of TGV increased (0.13, 0.21, and 0.23 L). SRaw showed similar frequency characteristics as Raw. As intra-group variability changed in parallel with the differences the diagnostic value of the parameters remained constant with frequency. Simplified SRaw alone and TGV combined with Raw exhibited no differences in their diagnostic values (81-84% correctly classified).(ABSTRACT TRUNCATED AT 250 WORDS)

Mucocele of paranasal sinuses in a young infant with cystic fibrosis.

We report the case of an infant who developed severe nasal obstruction as an unusual first presentation of cystic fibrosis (CF). Computed tomography (CT) showed homogeneous opacification of the symmetrically enlarged paranasal sinuses that gave the clue for the final diagnosis.

[Oscillatory impedance measurement of the respiratory tract in children]. / Oszillatorische Impedanzmessung des Respirationstraktes im Kindesalter.

The author reports on his own experiences with monofrequent and polyfrequent oscillatory impedance measurements of the respiratory tract in childhood. The monofrequent oscillatory process was tested in a total of 10 trials in respect of its suitability to estimate the complex respiratory resistance in the region of lower and upper respiratory tract in a total of 1071 children most of whom were healthy, some children having a diseased respiratory tract, between 3 and 19 years of age. In 268 children the nasal respiratory resistance was measured, in 803 the bronchial respiratory resistance. The polyfrequent oscillation method was compared in 2 examinations with body plethysmography and spirometry in respect of its discriminatory powers between healthy subjects and children suffering from asthma, and in respect of its suitability to prove bronchial hypersensitivity on carbachol provocation, using 93 healthy and 81 asthmatic children. The results of the 12 examinarions are surveyed and discussed.

[Bronchial provocation in children: a comparison between the polyfrequent oscillation method and body plethysmography]. / Bronchiale Provokation bei Kindern: Ein Vergleich zwischen der polyfrequenten Oszillationsmethode und der Bodyplethysmographie.

With the aid of the forced oscillation technique (FOT), parameters of the mechanics of respiration are measured with a minimum requirement of patient cooperation. This means that this technique is particularly suitable for use in children. The resistance (Rrs) established with the FOT correlates well with the airway resistance (Raw) measured with whole-body plethysmography (BP) (2, 4). So far, the blind resistance (Xrs) also simultaneously measurable with FOT, has received but little attention. The objective of this investigation was, in children, to compare all the resistances measurable with FOT with the parameters of BP during bronchial provocations with carbachol.

[Inhalation scintigraphy of the lung using the new ultrafine aerosol Technegas]. / Inhalationsszintigraphie der Lunge mit dem neuen ultrafeinen Aerosol "Technegas".

Evaporation of 99mTc-pertechnetate at about 2500 degrees C on a carbon surface generates an ultrafine aerosol of labelled carbon clusters. Its particle size of about 2-5 nm enables the aerosol to behave similarly to a gas regarding the ability of penetration. After inhalation, the radioactive particles adhere to the walls of the respiratory bronchioli and alveoli. The high concentration of the radioactivity in the argon carrier gas makes it possible to record a scintigram after a single deep breath. We studied four healthy volunteers and 79 patients including 34 with a tentative diagnosis of pulmonary embolism, 20 with bronchus carcinoma, and 15 with various other lung diseases. Ten of these patients were infants, the youngest being nine months old. All patients also had a perfusion scintigraphy.

Monitoring theophylline levels in serum and saliva using fluorescence polarization immunoassay and Seralyzer.

The reliability and predictive value of salivary theophylline levels was investigated in 58 children who were treated with oral sustained-release theophylline preparations for bronchial asthma. Serum and saliva levels were assessed by fluorescence polarization immunoassay (FPIA), and Seralyzer (reagent strip reflectance photometer method). Forty-six paired serum and saliva samples from 28 patients (Group 1) were used to develop a linear regression formula. This formula was tested on 130 paired serum and saliva samples from 32 patients (Group 2). When saliva theophylline levels were assayed using FPIA, 95% of serum levels were predicted within 30% of the measured value. Using Seralyzer, 95% of serum levels were predicted within 45% of the measured value. For patients with three and more paired serum and saliva specimens, individual regression formulas were determined showing considerable variation. This study indicates that salivary theophylline levels provide for an estimation of serum levels if FPIA is used. The Seralyzer technique is only useful for serum theophylline measurements. Using a special device it is now easier to obtain saliva samples than by conventional methods.