Negative Intratympanic Pressure Research Articles

Radiological and Audiological Assessment in Patients with Adenoid Hypertrophy Undergoing Adenoidectomy.

Enlarged adenoids in children can lead to obstruction of the ET, leading to negative intratympanic pressure and development of Otitis media effusion. Adenoid-nasopharyngeal ratio (ANR) on lateral radiograph of nasopharynx, is one of the most reliable and cost-effective ways of determining the size of adenoids with respect to the nasopharyngeal space. Patients who were clinically diagnosed with adenoid hypertrophy, above the age of 5years, undergoing adenoidectomy were included in the study. Lateral nasopharynx radiograph, Pure tone audiometry (PTA) and tympanometry were performed. The ANR calculated, graded, and compared with the PTA, tympanograms and size on endoscopic assessment. Taking 0.835 as cut-off value, significant correlation of ANR with PTA and impedance (p = 0.002) was found. 71% abnormal PTA and tympanogram was found with ANR > 0.835 whereas 30.8% with ANR < 0.835. ANR is a useful adjunct as a pre-operative tool for determining the need for adenoidectomy in paediatric patients who are not easily willing to undergo endoscopic evaluation. A major drawback is the lack of identification of lateral extent of adenoids.

Habitual use of push and pull plastic bottle caps is more prevalent among children with recurrent acute otitis media

ObjectiveThe use of a pacifier has been reported to be a causative factor of recurrent acute otitis media (RAOM) because the negative pressure which is generated during sucking may cause a negative intra-tympanic pressure and favour the reflux of nasopharyngeal secretions into the Eustachian tube. Push and pull (P&P) plastic bottle caps, recently marketed in Italy, might also induce negative nasopharyngeal pressure.This study was aimed to investigate if there is a difference in the prevalence of habitual use of P&P plastic bottle caps among children with a positive history of RAOM and healthy controls. MethodsA telephonic interview was performed in order to retrospectively evaluate the prevalence of habitual use of P&P plastic bottle cap among children with a history of RAOM and healthy controls, comparable to the former for environmental risk factors for RAOM. ResultsData were obtained from 57 Caucasian patients (males=36/57; 63.2%) with a median age of 59 (range=21–90) months, including 28 children with a history of RAOM and 29 healthy controls. Habitual use of P&P plastic bottle cap was significantly (p=0.047) more frequent in children with a history of RAOM (14/28; 50.0%) than in control group (7/29; 24.2%). Multivariate logistic regression analysis adjusted for age confirmed a significant association (p<0.01; Pseudo R2=0.2) between the use of P&P plastic bottle cap and a positive history of RAOM (adjusted OR=4.0; range=1.1–15.0). ConclusionsOur preliminary data show a significantly increased prevalence of P&P plastic cap bottle habitual users among children with a history or RAOM and support the need for larger studies to confirm the role of using P&P bottles as risk factor of RAOM and to identify the age groups at higher risk.

頭頸部手術を契機とした滲出性中耳炎

The present study evaluated the incidence of otitis media with effusion (OME) after head and neck surgery in patients who had been free from OME preoperatively.The subjects were 47 patients (90 ears; 22 males, 25 females; mean age 46.8 years; range 16-85 years) who had undergone head and neck surgery in our department. All ears had been free from middle ear diseases preoperatively. The operations were performed under general anesthesia in 42 cases, including 40 cases of nitrous oxide (N2O) anesthesia, and local anesthesia in 5 cases. Surgical sites were the middle ear in 2 cases, the nose in 9, the throat in 17, and the neck in 19. Otomicroscopic findings and tympanograms were evaluated three times; on the day before surgery, 1-2 days and 5-9 days after surgery.At the first-postoperative inspection of the ear drums, middle ear effusion was observed in 6 ears (6.7%). Effusion disappeared in all ears at the second-postoperative inspection. Tympanograms, which were type A in all ears before surgery, changed to type B in one ear (1.1%), type C1 in 8 ears (8.9%) and type C2 in 9 ears (10.0%) at the first-postoperative testing. All ears returned to type A except in one ear (from type C2 to type C1) at the second-postoperative testing. The average of intratympanic pressure was -17.5±2.2daPa (mean±SEM) and -59.6±8.4daPa in preoperative and the first-postoperative testing, respectively (p<0.001). The second-postoperative pressure was -22.6±2.7daPa, which did not significantlly differ from the preoperative pressure.In conclusion, we found that head and neck surgery might cause a decrease in intratympanic pressure. Temporary OME occurred in 6.7% ears and nitrous oxide (N2O) was used in all OME cases. We suppose that dysfunction of the eustachian tube was triggered by surgery and that N2O was related to the decrease in intratympanic pressure. Furthermore, continuation of negative intratympanic pressure promoted postoperative OME.

On the physics of the infant feeding bottle and middle ear sequela: Ear disease in infants can be associated with bottle feeding

Background: When using conventional feeding bottles, negative pressure is generated in the oral cavity, as well as, in the bottle when fluid is removed by sucking. The negative pressure inside the bottle causes the infant to suck excessively and the intraoral negative pressure may subsequently be transmitted to the middle ear via the eustachian tube. Methods: in seven infants, simultaneous pressure recordings were performed in the feeding vessel and the middle ear using three types of feeding bottles. Results: with conventional non-ventilated and under-ventilated bottles a negative pressure formed while the infant sucked and negative intratympanic pressure was frequently generated. Conclusions: it is suggested that this sequence of events may lead to secretory otitis and it's accompanying consequences. In contrast, a fully ventilated bottle showed positive pressure throughout the feeding procedure, which is similar to normal breast-feeding, and negative pressure changes were not recorded in the middle ear.

Eustachian tube function following adenoidectomy: an evaluation by sniffing

Recent investigations have demonstrated an association between sniff-induced negative middle ear pressure and otitis media with effusion. This is taken as evidence of Eustachian tube malfunction. Adenoidectomy is frequently performed as part of the surgical management for otitis media with effusion, but whether this affects Eustachian tube function is uncertain. The aim of this study was to investigate the hypothesis that if adenoidectomy improved Eustachian tube function, children who had undergone adenoidectomy would show less tendency to generate a high negative intratympanic pressure by sniffing. Eustachian tube function was studied actively in 40 children with otitis media with effusion. Twenty children, selected at random, underwent adenoidectomy and all 40 had a unilateral grommet inserted. Eighty-five percent of the children could create a negative middle ear pressure by sniffing, but there was no difference in the number of 'sniff + ve' children between the adenoidectomy and control groups (P greater than 0.5), or in the magnitude of the negative pressure induced. It is concluded that a high percentage of children with otitis media with effusion are capable of inducing a negative middle ear pressure by sniffing, but this parameter of Eustachian tube function is not affected by adenoidectomy.

Evacuation of the middle ear by sniffing: a cause of high negative pressure and development of middle ear disease.

Previous research on eustachian tube function has been devoted mainly to the study of the tubal opening ability and pressure equalization. This article summarizes a series of experimental studies focusing on the closing ability of the tube. Results support the belief that the purpose of the tube should be seen primarily as protecting the middle ear from the extensive pressure variations that physiologically take place in the nasopharynx. A number of studies of diseased ears have shown that tubal malfunction was characterized mainly by a reduced ability to withstand negative pressure in the nasopharynx. Sniffing can evacuate the middle ear, causing high negative intratympanic pressure. It seems likely that this mechanism is involved in the development of middle ear effusion and manifest retraction-type middle ear disease.

Eustachian tube closing failure. Occurrence in patients with cleft palate and middle ear disease.

Previous studies in patients with middle ear disease have shown that high negative pressure is frequently induced actively in the middle ear cavity by sniffing. The present study concerns 84 ears in 42 patients with cleft palate and middle ear disease. Sniff-induced evacuation of the middle ear was studied by direct pressure recording or tympanometry. Sixty-one percent of diseased ears showed tubal closing failure; 18% had constantly or intermittently wide-open tubes. In most cases, negative intratympanic pressure was not equalized on swallowing. It is suggested that eustachian tube malfunction in patients with cleft palate is constituted by the combination of closing failure with evacuation of the middle ear on sniffing, and by a secondary opening failure with inability to equalize the sniff-induced negative intratympanic pressure.

Eustachian tube pathophysiology

Studies of eustachian tube physiology have mainly focused on the ability of the tube to open. For this reason, impaired opening ability has been regarded as the basis of eustachian tube malfunction. Characteristic patterns have been found in pressure measurements in patients with chronic middle ear disease. Simultaneous measurements of nasopharyngeal and middle ear pressures in patients with atelectatic tympanic membranes and retraction cholesteatoma have shown that high negative intratympanic pressure is generated by the voluntary act of sniffing. Eustachian tube malfunction in these patients is thus characterized by failure of the tube to close.

Treatment of negative middle ear pressure and serous otitis media with Politzer's technique. An old procedure revisited.

This study sought to monitor changes in middle ear pressure with tympanometry after a simplified home politzerization maneuver in children who had excessive negative intratympanic pressure and/or serous otitis media. The mean middle ear pressure for 23 children was -201 mm H2O, whereas seven subjects displayed a flat tympanogram that was consistent with the medical diagnosis of serous otitis media. Middle ear pressure measurements with tympanometry at five and ten minutes after politzerization indicated successful tympanic ventilation in 91% and 85% of the ears, respectively. For children with negative intratympanic pressures of -250 mm H2O, data suggested that ventilation was sustained for at least 30 minutes. In general, results lend support for using home politzerization as an alternative or associative treatment in children with high negative pressure and/or serous otitis media.

Tubal closing failure in retraction type cholesteatoma and adhesive middle ear lesions.

In cases of retraction type cholesteatoma and related conditions it has been observed that the Eustachian tube may show a reduced ability to withstand respiratory pressure variations. The reduced resistance of the tube may play an important role in the development and course of middle ear disease. In the present study 42 subjects who had middle ear disease of this type and confirmed habitual sniffing behaviour were examined for symptoms and signs that would indicate a patulous tube. Different degrees of malfunction were recognized: in the presence of total closing failure, with an intermittently free transfer of respiratory pressures to the middle ear, the sniffing procedure maintains a negative intratympanic pressure. The condition is identical to the patulous tube state in the classical sense. In relative closing failure there is no free pressure transfer, and no patulous tube symptoms. Sniffing may however cause a repeated evacuation of the middle ear space. The results of this study cast doubt upon th...

Relationship of pre-operative eustachian tube function to myringoplasty.

The ventilatory function of the Eustachian tube has been measured in eighty cases prior to myringoplasty. Three grades of good, moderate and poor Eustachian function are described depending on the residual negative intratympanic pressure. 80X of cam operated on with good and moderate grades of Eustachian function (less than - 200 mm residual negative pressure), had a healed tympanic membrane, a hearing improvement, and an air containing middle ear cavity. However, only 29% of cases operated on with poor Eustachian function had a similarly successful result. Limitations of the “negative middle ear pressure test” are discussed, but it is suggested that this test is useful regarding a decision about the optimum time for closure of a perforation by myringoplasty or other form of tympanoplasty.

GELL'E TEST WITH B'EK'ESY AUDIOMETRY. III. FINDINGS WITH SALPINGITIS.

After describing the technique of performing the Gelle test with Bekesy audiometry, and following the definition of the range of normal values, this paper is devoted to the findings in cases of salpingitis. It could be confirmed that negative intratympanic pressure is counteracted by negative meatal pressure. At that moment, the hearing loss resulting from tubal obstruction is temporarily corrected.It appears that negative pressure application during the Gelle test closes the air-bone gap of salpingitis momentarily. For this reason, the normal threshold shift, observed with negative meatal pressure, is inverted to an improved hearing level. Three patterns of Gelle test results are discussed, which seem to reflect the degree of tubal obstruction.