Radiographic Mastoid and Middle Ear Effusions in Intensive Care Unit Subjects

[ENT in zero g: the cosmic challenges of otolaryngology]

Manned spaceflight places special demands on the human body, including the organs in the ENT region. These organs play a critical role in maintaining the health and safety of astronauts in space. In this paper, we review common ENT problems of spaceflight, including upper airway edema, middle ear and mastoid effusions, hearing loss, and dizziness with nausea. We discuss the underlying mechanisms contributing to these complaints, their clinical manifestations, and potential treatment strategies. In addition, we examine the potential impact of these conditions on astronaut health and mission outcomes. Finally, we emphasize the importance of preventive measures and future research in this area to optimize astronaut health and safety on future missions.

Quantitative transmastoid ultrasound for detecting middle ear effusion in pediatric patients

BACKGROUND AND OBJECTIVE

Ultrasound has emerged as a promising modality for detecting middle ear effusion (MEE) in pediatric patients. Among different ultrasound techniques, ultrasound mastoid measurement was proposed to allow noninvasive detection of MEE by estimating the Nakagami parameters of backscattered signals to describe the echo amplitude distribution. This study further developed the multiregional-weighted Nakagami parameter (MNP) of the mastoid as a new ultrasound signature for assessing effusion severity and fluid properties in pediatric patients with MEE.

METHODS

A total of 197 pediatric patients (n = 133 for the training group; n = 64 for the testing group) underwent multiregional backscattering measurements of the mastoid for estimating MNP values. MEE, the severity of effusion (mild to moderate vs. severe), and the fluid properties (serous and mucous) were confirmed through otoscopy, tympanometry, and grommet surgery and were compared with the ultrasound findings. The diagnostic performance was evaluated using the area under the receiver operating characteristic curve (AUROC).

RESULTS

The training dataset revealed significant differences in MNPs between the control and MEE groups, between mild to moderate and severe MEE, and between serous and mucous effusion were observed (p < 0.05). As with the conventional Nakagami parameter, the MNP could be used to detect MEE (AUROC: 0.87; sensitivity: 90.16%; specificity: 75.35%). The MNP could further identify effusion severity (AUROC: 0.88; sensitivity: 73.33%; specificity: 86.87%) and revealed the possibility of characterizing fluid properties (AUROC: 0.68; sensitivity: 62.50%; specificity: 70.00%). The testing results demonstrated that the MNP method enabled MEE detection (AUROC = 0.88, accuracy = 88.28%, sensitivity = 92.59%, specificity = 84.21%), was effective in assessing MEE severity (AUROC = 0.83, accuracy = 77.78%, sensitivity = 66.67%, specificity = 83.33%), and showed potential for characterizing fluid properties of effusion (AUROC = 0.70, accuracy = 72.22%, sensitivity = 62.50%, specificity = 80.00%).

CONCLUSIONS

Transmastoid ultrasound combined with the MNP not only leverages the strengths of the conventional Nakagami parameter for MEE diagnosis but also provides a means to assess MEE severity and effusion properties in pediatric patients, thereby offering a comprehensive approach to noninvasive MEE evaluation.

Eustachian tube dysfunction in an intensive care unit: A prospective observational study

Background

Eustachain tube (ET) dysfunction can aggravate the morbidity in ICU patients, but is often ignored. In this prospective observational study we followed a cohort of patients (without pre-existing ET dysfunction) requiring in-patient management, hospitalized either to ICU or to non ICU wards, for any development of ET dysfunction during hospitalization.

Methods

Patients requiring hospitalization to ICU or non ICU wards from Dec 2018 to Jun 2019 were included. Those with pre-existing ET dysfunction, disease of ear/nose or sinuses, head neck tumours and history of radiotherapy or glucocorticoid therapy were excluded. All patients were evaluated by serial tympanometry. Type A curve was considered normal while type B, C1 and C2 were considered as ET dysfunction.

Results

There were 385 patients, 258 (67.01%) males and 127 (32.99%) females in the ICU group; while non ICU group comprised 129 patients, 86 (66.67%) males and 43 (33.33%) females. ET dysfunction developed in 107 (27.79%) patients in ICU group, but only in 3 (2.3%) in non ICU group (Relative risk 11.95, 95% CI 3.86 to 36.99, P < 0.0001). Within ICU, ET dysfunction showed significant positive association with endotracheal intubation, Ramsay sedation score and number of days on tracheostomy; but not with age, male gender, number of days in ICU, mechanical ventilation or route of feeding.

Conclusion

Our study demonstrates high incidence of ET dysfunction in patients admitted to ICU.

Differences in mastoid and middle-ear cavity opacification in CT between intensive care patients and patients with acute mastoiditis requiring surgical treatment

Purpose

To stratify differences in visual semantic and quantitative imaging features in intensive care patients with nonspecific mastoid effusions versus patients with acute mastoiditis (AM) requiring surgical treatment.

Methods

We included 48 patients (male, 28; female, 20; mean age, 59.5 ± 18.1 years) with mastoid opacification (AM, n = 24; control, n = 24) who underwent clinically indicated cerebral CT between 12/2007 and 07/2018 in this retrospective study. Semantic features described the extend and asymmetry of mastoid and middle-ear cavity opacification and complications like erosive changes. Minimum, maximum and mean Hounsfield unit (HU) values were obtained as quantitative features. We analyzed the features employing univariate testing.

Results

Compared to intensive care patients, AM patients revealed asymmetric mastoid or middle-ear cavity opacification (likelihood-ratio (LR) < 0.001). Applying a dedicated threshold of the extent of opacification, AM patients reached significance levels of LR = 0.042 and 0.002 for mastoid and middle-ear cavity opacification. AM cases showed higher maximum and mean HU values (p = 0.009, p = 0.024).

Conclusions

We revealed that the extent and asymmetry of mastoid and middle-ear cavity opacification differs significantly between AM patients and intensive care patients. Multicenter research is needed to expand our cohort and possibly pave the way to build a non-invasive predictive model for AM in the future.

The Prevalence of Incidental Mastoid Opacification and the Need for Intervention: A Meta-Analysis

OBJECTIVES/HYPOTHESIS

The increasing use of cross-sectional imaging has led to the predicament of incidental mastoid opacification (IMO). We investigated the prevalence of IMO and the clinical need for ENT assessment or intervention when identified.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The PRISMA statement standards were used to search electronic databases including Medline, Embase, PubMed, and Web of Science. The selection criteria were mastoid opacification found on computed tomography (CT) or magnetic resonance imaging (MRI) as incidental findings.

RESULTS

A total of 16 studies were identified for qualitative analysis and 15 for quantitative analysis, mainly retrospective. The pooled prevalence of IMO in 246,288 patients was 8.4% (95% CI 5.5-12.0). The prevalence of IMO was significantly higher in studies with children (17.2%, 95% CI 10.9-24.6) than those with adults (6.1%, 95% CI 3.3-9.6); smaller sample size studies (12.4%, 95% CI 8.1-17.3) compared to larger sample size studies (4.1%, 95% CI 1.5-7.8); and when IMO was detected by viewing images (14.5%, 95% CI 9.9-19.8) compared to reading reports (3.5%, 95% CI 1.3-6.6). Imaging modality was not a significant moderator due to similar IMO rate on CT (8.6%, 95% CI 1.8-19.7) and MRI (10.4%, 95% CI 4.9-17.6). Nine studies reported on clinical outcomes of patients with IMO, and none reliably reported any cases of clinical mastoiditis.

CONCLUSIONS

The term "mastoiditis" on radiology reports based on IMO does not indicate a clinical diagnosis of mastoiditis, although the current body of evidence is limited. Otolaryngology review is suggested if clinical correlation detects otological signs or symptoms.

LEVEL OF EVIDENCE

NA. Laryngoscope, 2021.

Gravity and Mastoid Effusion

BACKGROUND

Asymptomatic mastoid effusions have recently been observed in astronauts returning from long-term spaceflight. In hospitalized patients, mastoid effusion increases the risks for bacterial otitis and mastoiditis. We reasoned that cephalad fluid shifts during strict -6° head down tilt bed rest could reproduce space-flight associated mastoid effusion and that artificial gravity may reverse the response.

METHODS

The recent Artificial Gravity Bed Rest Study-European Space Agency study (AGBRESA) tested influences of artificial gravity during 60 days head down bed rest on a short-arm human centrifuge in healthy participants. The two intervention groups received daily artificial gravity with 30 minutes continuous artificial gravity or intermittent artificial gravity. A third group served as a control group and received no artificial gravity. We assessed cranial magnetic resonance images for mastoid effusions 1 day before bed rest, at days 14 and 52 of bed rest, and 3 days after bed rest.

RESULTS

None of the participants exhibited mastoid effusions before bed rest. Six participants showed mastoid effusions at bed rest day 14 (4 continuous, 2 intermittent, 0 control). Fifteen participants showed mastoid effusions at bed rest day 52 and 3 days after bed rest (7 continuous, 3 intermittent, 5 control).

CONCLUSIONS

Mastoid effusions commonly occur during strict head down tilt bed rest. The model can be applied to study the mechanisms and potential countermeasures for space flight-associated mastoid effusions. Formation of mastoid effusions during head down tilt bed rest is not prevented by daily 30 minutes short-arm intermittent or continuous centrifugation.

History of Mastoidectomy: PubMed, Best Matches, Secondary References, and Inaccuracies

OBJECTIVE

PubMed is the world's largest online collection of biomedical literature citations. A PubMed search (October 11, 2019) using the medical subject heading terms "history" and "mastoidectomy" was conducted. The heading "best matches" listed as first article "A brief history of mastoidectomy," a very relevant free full text. The aim of this study is to validate or not the relevance attributed to this study as the first article listed in best matches.

METHODOLOGY

All the references of the article mentioned before 1860 were checked, further completed with other original sources, and studied again, with particular attention to their extracted quotes.

RESULTS

Surprisingly, this article contains many inaccuracies, notably concerning Galen, Lucas van Leyden, Paré, Riolan the Younger, Justus von Berger, Jasser, Dezeimeris, Wilde and Toynbee. This was most certainly related to blind trust of some secondary references.

CONCLUSION

Never trust secondary references. This article also raises questions on the validity and the relevance of the best matches algorithm in PubMed.

Spaceflight-Associated Changes in the Opacification of the Paranasal Sinuses and Mastoid Air Cells in Astronauts

Importance

Head congestion is one of the most common somatic symptoms experienced by astronauts during spaceflight; however, changes in the opacification of the paranasal sinuses or mastoid air cells in astronauts have not been adequately studied.

Objectives

To quantify preflight to postflight changes in the opacification of the paranasal sinuses and mastoid air cells in Space Shuttle astronauts and International Space Station (ISS) astronauts and to assess whether there are differences between the 2 groups of astronauts.

Design, Setting, and Participants

This cohort study examined preflight and postflight head magnetic resonance images (MRIs) of 35 astronauts who had participated in either a short-duration (≤30 days) Space Shuttle mission or a long-duration (>30 days) ISS mission and had undergone both preflight and postflight MRI. Images were obtained before and after spaceflight. Images were evaluated by 2 neuroradiologists blinded to which mission each astronaut had flown and to which images were preflight or postflight images.

Exposure

Spaceflight on the Space Shuttle or the ISS.

Main Outcomes and Measures

Measured outcomes included preflight to postflight changes in Lund-Mackay scores for the paranasal sinuses and in scores grading mastoid effusions.

Results

Most astronauts in both the Space Shuttle group (n = 17; 15 men; mean [SD] age at launch, 47.7 [3.1] years) and the ISS group (n = 18; 14 men; mean [SD] age at launch, 48.6 [4.7] years) exhibited either no change or a reduction in paranasal sinus opacification as seen on postflight MRI scans (Space Shuttle group: 6 [35.3%] had no sinus opacification before or after spaceflight, 5 [29.4%] had less sinus opacification after spaceflight, 3 [17.6%] had the same amount of sinus opacification before and after spaceflight, and 3 [17.6%] had increased paranasal sinus opacification after spaceflight; ISS group: 8 [44.4%] had no sinus opacification before or after spaceflight, 4 [22.2%] had less sinus opacification after spaceflight, 1 (5.6%) had the same amount of sinus opacification before and after spaceflight, and 5 [27.8%] had scores consistent with increased paranasal sinus opacification after spaceflight). Long-duration spaceflight (ISS group) was associated with an increased risk of mastoid effusion relative to short-duration spaceflight (relative risk, 4.72; 95% CI, 1.2-18.5). Images were obtained a mean (SD) 287.5 (208.6) days (range, 18-627 days) prior to and 6.8 (5.8) days (range, 1-20 days) after spaceflight. Astronauts had undergone either a mean (SD) of 13.6 (1.6) days of spaceflight on the Space Shuttle (17 astronauts) or 164.8 (18.9) days on the ISS (18 astronauts).

Conclusions and Relevance

This study found that exposure to spaceflight conditions on the ISS is associated with an increased likelihood for the formation of mastoid effusions. There was no association between exposure to spaceflight conditions and changes in paranasal sinus opacification. The limitations of this study include lack of information concerning medical history and mission-specific operational experience for individual astronauts. Further studies are indicated to determine the cause and composition of the mastoid effusions.

Emergency radiologic approach to mastoid air cell fluid

Mastoid air cell fluid is a commonly seen, but often dismissed finding. Given the location of the mastoid portion of the temporal bone and its location adjacent to vital structures, a careful evaluation is important for the emergency radiologist. While occasionally benign, fluid within the mastoid air cells can be an early sign of more severe pathology, and familiarity of regional anatomy allows for early identification of disease spread. This article describes the important anatomy, the common pathologies, and a radiologic approach to assessing the mastoid air cells in order to guide referring clinicians.

Relationship between Increased Intracranial Pressure and Mastoid Effusion

Objective

This study aimed to assess the relationship between increased intracranial pressure (ICP) and mastoid effusions (ME).

Methods

Between January 2015 and October 2018, patients who underwent intracranial surgery and had ICP monitoring catheters placed were enrolled. ICP was recorded hourly for at least 3 days. ME was determined by the emergence of opacification in mastoid air cells on follow-up brain imaging. C-reactive protein (CRP) levels, presence of endotracheal tube (ETT) and nasogastric tube (NGT), duration of intensive care unit (ICU) stay, duration of mechanical ventilator application, diagnosis, surgical modalities, and presence of sinusitis were recorded. Each factor’s effect on the occurrence of ME was analyzed by binary logistic regression analyses. To analyze the independent effects of ICP as a predictor of ME a multivariable logistic regression analysis was performed.

Results

Total of 61 (53%) out of 115 patients had ME. Among the patients who had unilateral brain lesions, 94% of subject (43/50) revealed the ipsilateral development of ME. ME developed at a mean of 11.1±6.2 days. The variables including mean ICP, peak ICP, age, trauma, CRP, ICU stays, application of mechanical ventilators and presence of ETT and NGT showed statistically significant difference between ME groups and non-ME groups in univariate analysis. Sex and the occurrence of sinusitis did not differ between two groups. Adding the ICP variables significantly improved the prediction of ME in multivariable logistic regression analysis.

Conclusion

While multiple factors affect ME, this study demonstrates that ICP and ME are probably related. Further studies are needed to determine the mechanistic relationship between ICP and middle ear pressure.

Fluid signal in the mastoid is a common incidental finding on MRI of the brain

Incidental findings are common on patients undergoing magnetic resonance imaging (MRI) of the brain. Fluid signal in the mastoid can be such an incidental finding on MRI of the brain. In only a small number of patients, this relates to inflammatory disease of the middle ear or mastoid. In a small retrospective study, the prevalence of this finding has been studied. Fluid signal in the mastoid was found in 21 out of 84 patients (25%). Only in two patients MRI revealed a cause for the mastoid fluid (mastoid osteolysis in a patient with metastatic breast cancer and presumed recurrent cholesteatoma in another patient). Two patients reported about longstanding presbyacusis. At the initial examination, none of the patients reported symptoms of an inflammatory otological disease, and clinical examination was unremarkable in all patients. In conclusion, fluid signal in the mastoid seems to be a frequent incidental finding in asymptomatic patients. A diagnosis of mastoiditis should only be made if there are distinct clinical findings.

Eustachian tube dysfunction leading to middle-ear pathology in patients on chronic mechanical ventilation

OBJECTIVE

This study aimed to investigate the prevalence of and risk factors for Eustachian tube dysfunction leading to middle-ear pathology in patients on chronic mechanical ventilation via tracheostomy tube.

METHODS

A total of 40 patients on chronic ventilation were included in a prospective cohort study. Middle-ear status was determined by tympanometry. Tympanograms were categorised as types A, B or C; types B and C were defined as middle-ear pathology.

RESULTS

In all, 57 ears of 40 patients were examined. Disease was found in at least 1 ear in 26 out of 40 patients. Middle-ear pathology was found in 25 out of 34 patients who were tube fed (via nasogastric tube or percutaneous endoscopic gastrostomy) vs 1 patient out of the 6 fed orally (p = 0.014), and in 23 out of 31 with conscious or cognitive impairment vs 3 out of 9 cognitively intact patients (p = 0.044).

CONCLUSION

Middle-ear pathology is common in patients on chronic mechanical ventilation via tracheostomy tube. The highest prevalence was in those with impaired consciousness or cognition, and oral feeding appeared protective.