Accuracy of the minimal leak test for endotracheal cuff pressure monitoring

Objectives To determine the accuracy of the minimum leak test as a surrogate for target endotracheal cuff pressure of 20–30 cm H2O in intubated patients. Methods Cuff pressures were measured at the University of Miami Hospital using the minimum leak test on every intubated patient once per shift, then cuff pressure was reevaluated using handheld numerical manometers and recorded pressures above or below the target range, readjusting the pressure as needed. This assessment was repeated throughout each patient's intubation for up to 6 days. The readjustment rate of the test and the probability of a patient needing at least one adjustment were determined. Results One hundred twenty‐two patients were evaluated. Median age was 67 years (range 29–95), 52% were male, 48% were female. Patients were followed for an average of 4.7 days. Seven hundred twenty‐two minimum leak tests were performed. Of these, 170 required readjustment into the target range (24% readjustment rate). Of the tests outside target range, 66% of cuffs were overinflated and 34% were underinflated. Fifty‐five percent of patients required at least one adjustment. Conclusion Despite ubiquitous use of the minimum leak test for endotracheal cuff pressure adjustment, the test has an unacceptably high error rate resulting in cuff pressures above or below the target range. Most patients will require at least one adjustment throughout an intubation, putting them at risk for tracheal injury, stenosis, or leak and aspiration. The minimum leak test is not sufficiently accurate for endotracheal cuff pressure monitoring. Formal manometry is superior and should be used to optimize patient outcomes. Level of Evidence 4 Laryngoscope, 130:1646–1650, 202

Development of cholesterol granuloma in a temporal bone petrous apex previously containing marrow exposed to air cells

There is ongoing debate on the pathogenic mechanisms of cholesterol granuloma formation in the temporal bone. The purpose of this report is to provide evidence in support of the exposed marrow hypothesis in explaining the pathogenesis of petrous apex cholesterol granuloma. Retrospective single case study. The primary outcome evaluated was the diagnosis of a new cholesterol granuloma in a petrous apex that previously demonstrated radiologic evidence of bone marrow exposed to petrous apex air cells. A patient with a unilateral petrous apex cholesterol granuloma develops a new, contralateral cholesterol granuloma in a hyperpneumatized temporal bone petrous apex shown previously to have medullary bone exposed to air cells. This report implicates the medullary-air cell interface in a hyperaerated temporal bone petrous apex in the development and growth of a petrous apex cholesterol granuloma

Otoprotective Properties of Mannitol Against Gentamicin Induced Hair Cell Loss

BACKGROUNDGentamicin is a widely used antibiotic, which causes hearing loss because of destruction of auditory hair cells. Mannitol has been shown to have cytoprotective properties in the cochlea both in vitro and in vivo. Mannitol has been shown to be safe in concentrations up to 100 mM in organ of Corti explants. It is proposed as an otoprotective agent against gentamicin ototoxicity. METHODSOrgan of Corti were dissected from P-3 rat pups and cultured under the following conditions for 96 hours1) control, 2) gentamicin (10 μM for all hair cell count experiments), 3) gentamicin + mannitol 10 mM, 4) gentamicin + mannitol 50 mM, and 5) gentamicin + mannitol 100 mM. The tissues were then fixed and stained, and hair cells were counted for segments of the apex, middle, and basal turns. Quantitative RT-PCR (qRT-PCR) was performed on organ of Corti explant extracted RNA after 24 hours in vitro1) control; 2) gentamicin (100 μM for all gene expression and CellRox experiments); 3) gentamicin +mannitol 100 mM; and 4) mannitol 100 mM for tumor necrosis factor–alpha (TNF-α), TNF-α receptor (TNFR1A), interleukin-1 beta (IL-1β) and cyclooxygenase-2 (COX-2). In vitro examination of oxidative stress was performed for the same test groups at 24 hours using CellRox Deep Red assay. RESULTSGentamicin induced loss of both inner hair cells and outer hair cells with increasing severity from apex to middle to basal segments (Pearson r = −0.999 for inner hair cells and −0.972 for outer hair cells). Mannitol demonstrated dose-dependent otoprotection of IHCs and outer hair cells (p 0.05). CONCLUSIONGentamicin ototoxicity is increasingly severe from the apex to basal turn of the cochlea. Treatment with mannitol prevents gentamicin-induced hair cell loss in a dose-dependent manner, protecting both IHCs and outer hair cells. Mannitol appears to act as a free radical scavenger to reduce the cytotoxic effects of gentamicin by reducing the level of oxidative stress

Free tissue transfer for skull base reconstruction - a review

Evolutions in skull base surgery and reconstructive technique have given surgeons the confidence to resect and repair increasingly advanced skull base pathologies. Free tissue transfer (FTT) provides a versatile option capable of addressing numerous simultaneous reconstructive goals. This review highlights some of the nuances, challenges, and considerations of performing FTT for skull base reconstruction in the anterior, central and lateral skull base. This review combines the expert opinion of the senior authors with those of the field at large as queried through PubMed searches regarding skull base reconstruction and FTT. Reconstructive goals include separation of intracranial from extracranial cavities, obliteration of dead space, and protection of vascular and neural structures. Atypical vascular pedicle management is commonly needed, especially for endonasal and central skull base resection. Virtual surgical planning may be beneficial for complex bony reconstruction. Familiarity with common complications such as cerebrospinal fluid leak, nasocutaneous fistula, and inferior flap displacement, as well as associations for their development, can help plan the reconstruction to minimize morbidity

Macrophages as independent prognostic factors in small T1 breast cancers

Breast cancer is the second leading cause of death by cancer in women in the United States. The occurrence of high numbers of macrophages in the tumor stroma has been associated with tumor progression and poor prognosis in breast and other solid malignancies. However, macrophage numbers in tumors have not been validated as a prognostic factor in clinical practice. The present analysis was designed as a pilot study aimed at determining whether the presence of CD68+ macrophages is an independent prognostic factor in small T1 estrogen receptor (ER)+ breast cancers across three different ethnic groups, i.e. African-American, Latina and Caucasian women. A retrospective pilot analysis of 30 T1 breast cancer cases encompassing these three ethnic groups was carried out. African-American and Latina women present with less incidence but more aggressive breast cancer disease and, therefore, proportionally higher death rates. Using immunohistochemistry, we sought to identify whether there was any association between the presence and density of CD68+ macrophages and standard prognostic markers with overall survival in these groups. Our data revealed that overall survival did not differ significantly for the occurrence or density of CD68+ macrophages in T1 ER+ tumors. There were also no significant differences in overall survival for the occurrence of CD68+ macrophages across ethnicities, although macrophage numbers were significantly higher in tumors from African-American and Latina than in Caucasian patients. Importantly, but not surprisingly, the absence of the progesterone receptor was associated very strongly with decreased overall survival. This pilot project shows that CD68+ macrophages are not pivotal in determining tumor prognosis in early T1 breast cancers. New studies are presently being conducted to assess the value of different macrophage markers and macrophage activation profiles as prognostic factors in breast cancers of different clinical stages, using a larger number of patients among these three different ethnicities

Antibody-specific detection of CAIX in breast and prostate cancers.

Contains fulltext : 80121.pdf (publisher's version ) (Closed access)Carbonic anhydrase IX (CAIX) is frequently expressed in human tumors and serves as a marker for hypoxia. Further, CAIX expression is considered a predictor of poor survival in many, but not all, cancer types. Herein, we compare the specificity of two CAIX antibodies: the M75, monoclonal antibody which recognizes an epitope in the N-terminus and a commercially available polyclonal antibody generated against a C-terminal peptide (NB100-417). Western blot analysis of multiple breast cell lines revealed that the polyclonal antibody detected both membrane-bound and soluble proteins. The M75 antibody recognized only the membrane-bound species, which is presumed to be CAIX. These data were confirmed in an aggressive prostate cell line. We further compared these antibodies in prostate tumors by immunohistochemistry. Staining with NB100 was comparable to that of the M75 antibody, but only at high dilution. Otherwise, cytoplasmic staining was also noted. Two-dimensional gel electrophoresis followed by mass spectrometric analysis revealed that the cytoplasmic protein detected by NB100 is beta-tubulin. This cross-reactivity could lead to false-positives for CAIX expression in samples where cytosolic proteins are present