Host and microbial characteristics associated with recurrent prosthetic joint infections.

Approximately 20% of patients after resection arthroplasty and antibiotic spacer placement for prosthetic joint infection develop repeat infections, requiring an additional antibiotic spacer before definitive reimplantation. The host and bacterial characteristics associated with the development of recurrent infection is poorly understood. A case-control study was conducted for 106 patients with intention to treat by two-stage revision arthroplasty for prosthetic joint infection at a single institution between 2009 and 2020. Infection was defined according to the 2018 Musculoskeletal Infection Society criteria. Thirty-nine cases ("recurrent-periprosthetic joint infection [PJI]") received at least two antibiotic spacers before clinical resolution of their infection, and 67 controls ("single-PJI") received a single antibiotic cement spacer before infection-free prosthesis reimplantation. Patient demographics, McPherson host grade, and culture results including antibiotic susceptibilities were compared. Fifty-two (78%) single-PJI and 32 (82%) recurrent-PJI patients had positive intraoperative cultures at the time of their initial spacer procedure. The odds of polymicrobial infections were 11-fold higher among recurrent-PJI patients, and the odds of significant systemic compromise (McPherson host-grade C) were more than double. Recurrent-PJI patients were significantly more likely to harbor Staphylococcus aureus. We found no differences between cases and controls in pathogen resistance to the six most tested antibiotics. Among recurrent-PJI patients, erythromycin-resistant infections were more prevalent at the final than initial spacer, despite no erythromycin exposure. Our findings suggest that McPherson host grade, polymicrobial infection, and S. aureus infection are key indicators of secondary or persistent joint infection following resection arthroplasty and antibiotic spacer placement, while bacterial resistance does not predict infection-related arthroplasty failure.

No-show rates to a sleep clinic: drivers and determinants.

STUDY OBJECTIVES: Attendance to sleep clinic appointments is imperative to diagnose sleep-related disorders and to offer appropriate treatment. As part of our quality assurance program, we assessed predictors of no-show rates at our sleep clinic. We hypothesize that no-show rates can be predicted by demographics, appointment type (new vs established) and timing, and insurance status. METHODS: We performed a 10-month, retrospective chart review of patients scheduled at Saint Louis University's SLUCare Sleep Disorders Center. Multivariable logistic regression was used to determine which factors were independently associated with no-show. RESULTS: A total of 2,532 clinical visits were reviewed, and the overall no-show rate was 21.2%. Factors associated with a higher incidence of no-show rates included younger age (17-40 years: 21.5%; 41-64 years: 23.5%; ≥65 years: 14.0%; P < .0001), appointment type (new: 30.5% vs established: 18.3%; P < .0001), and insurance status (no insurance: 24.6% vs public: 22.6% vs private: 15.9%; P < .0001). Multivariable logistic regression confirmed the independent association between no-show and age ≤ 40 years (adjusted odds ratio = 1.72; 95% confidence interval: 1.44, 2.20), new patient status (adjusted odds ratio = 1.78; 95% confidence interval: 1.44, 2.20), and absence of health insurance (adjusted odds ratio = 1.62; 95% confidence interval: 1.24, 2.11). Sex, appointment time, day of the week, and season did not significantly influence no-show rates. CONCLUSIONS: Independent predictors of no-show appointments included younger age, new patient status, and lack of health insurance. Our findings will aid future efforts to identify patients with high predictors of nonadherence. Further studies are needed to develop methods to decrease no-show rates once high-risk appointments have been identified.

Exercise-Induced Oxygen Desaturation during the 6-Minute Walk Test.

The 6-minute walk test (6MWT) is not intended to document oxygen (O2) desaturation during exertion but is often used for this purpose. Because of this, it only has modest reproducibility in determining the need for ambulatory O2 therapy in patients with cardiopulmonary disease. The diagnostic and prognostic value of detecting exertional O2 desaturation is still unknown. The aims of this study were to estimate the prevalence of O2 desaturation during a 6MWT based on pulse oximetry measurements at the beginning and end of a 6MWT in a clinical population of patients with suspected cardiopulmonary disease and to determine whether the pulmonary function test (PFT) can predict exercise-induced desaturation during a 6MWT. This retrospective cohort study reviewed the results of the 6MWT and the PFT (i.e., spirometry, lung volumes, and diffusion capacity) of all patients who were evaluated for suspected cardiopulmonary disease at an academic medical center during a 5-year study period. The patients were categorized into three groups based on the change in O2 saturation by pulse oximetry (SpO2) from start to end of the 6MWT: (1) SpO2 decreased by ≥3%; (2) SpO2 unchanged (-2 ≤ Δ ≤ 0%); and (3) SpO2 increased by ≥1%. Demographic, anthropometric, and lung function measurements were analyzed to determine which factors predicted O2 desaturation during the 6MWT. Of the 319 patients who underwent the 6MWT and the PFT from November 2005 until December 2010 (mean age = 54 ± 0.78 years, 63% women, 58% Whites, body mass index = 29.63 ± 8.10 kg/m2), 113 (35%) had a decreased SpO2, 146 (46%) had no change, and 60 (19%) had an increased SpO2 from the start to end of test. Our bivariate analysis found age, spirometric measures, and diffusion capacity for carbon monoxide (DLCO) had statistically significant inverse associations with the SpO2 change category (p < 0.001). Both a 3% and 4% drop in SpO2 during the 6MWT were statistically significantly associated with an older age, a higher prevalence of obstruction, and reduced forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, DLCO and 6-minute walk distance (6MWD). Multivariable logistic regression analyses revealed that only DLCO was a significant independent predictor of the change in SpO2 and a ≥ 4% O2 desaturation during a 6MWT. Receiver operating curve analysis indicates DLCO cut-off of 45% is 82% sensitive and 40% specific in identifying ≥4% O2 desaturators, with an area under the curve of 0.788 ± 0.039 (p < 0.001). The prevalence of a ≥ 3% oxygen desaturation via pulse oximetry during a 6MWT in our clinical population of patients with suspected cardiopulmonary disease was 35%. Although age, spirometric lung volumes, and DLCO had statistically significant unadjusted inverse associations with the change in SpO2 during a 6MWT, the DLCO is the only significant independent predictor of both the magnitude of the change in SpO2 and the occurrence of O2 desaturation of at least 4%, respectively, during the test. Clinical Implications: A DLCO cut-off of 45% may be useful in identifying patients at risk for exertional hypoxemia during a 6MWT.

Association between Body Mass Index (BMI) and fraction of exhaled nitric oxide (FeNO) levels in the National Health and Nutrition Examination Survey (NHANES) 2007-2010.

PURPOSE: Obesity is characterised by chronic, low-grade systemic inflammation. Elevated FeNO levels reflect airway inflammation in various lung diseases including asthma. METHODS: This is a cross-sectional analysis of data from NHANES 2007-2010. Participants younger than 20 years old with history of cough/cold symptoms in the past 7 days, smoking, exercise in the previous hour, consumption of nitric oxide rich meats/vegetables, or use of inhaled corticosteroids during the previous 2 days were excluded. BMI (in kg/m2) was divided in to 4 categories: underweight (UW) (0-18.5), Normal (N) (≥18.5 to <25), Overweight (OW) (≥25 and <30) and Obese (O) ≥30. RESULTS: There were a total of 149,629,652 weighted participants: UW (22,235,218), N (45,021,536), OW (5,1670,522) and O (50,199,974); 50.36% were men and 49.63% were women. The mean age increased with BMI category [p<.0001]. Mean FeNO levels (in ppb) increased with increasing BMI category: UW (12.52±1.05) N (16.25±0.64), OW (16.62±0.34), and O (16.78±0.39) [p=0.0035]. FEV1/FVC (%) decreased with increasing BMI category: UW (80.68) compared to N (78.51), OW (77.67) and O (78.72) [p=0.0014]. There is a weak yet statistically significant correlation between FeNO levels and both age, BMI. Multivariate analysis predicting FeNO based on BMI category, adjusting for age, gender, race and airway obstruction found age less than 60 years, male gender, certain races and UW BMI category were associated with statistically significantly lower FeNO levels. CONCLUSIONS: Older age and male gender are associated with increased FeNO levels. Controlling for age, gender, and race, obese individuals have a statistically significantly higher FENO than underweight individuals.

Sleep disorders in chronic liver disease.

Sleep-related complaints and disturbances are increasingly recognized in the setting of chronic liver disease and have recently been shown to be an important prognostic factor in patients with advanced chronic liver disease. This article reviews the literature surrounding sleep disturbances and disorders in a variety of types of chronic liver disease. This includes the association of sleep disturbances with hepatitis C and antiviral therapy, primary biliary cirrhosis, and Wilson disease as well as the circadian rhythm abnormalities present in cirrhosis and hepatic encephalopathy. The association between chronic liver disease, particularly nonalcoholic fatty liver disease, and sleep-disordered breathing is also reviewed in detail.

Endobronchial leiomyoma: case report and literature review.

Endobronchial leiomyomas are rare benign tumors of the lung, arising from the smooth muscle of the bronchial tree. Symptomatology is based on the degree of endoluminal bronchial obstruction, and surgical resection has generally been the mainstay of treatment. We describe a mechanically ventilated patient with recurrent atelectasis and a postobstructive pneumonia caused by an occlusive endobronchial leiomyoma who was successfully weaned off the ventilator after treatment with argon plasma coagulation delivered via flexible bronchoscopy. We also briefly review the literature.

Aging-related sleep changes.

Normal aging is accompanied by changes in the sleep quality, quantity, and architecture. Specifically, there appears to be a measurable decrease in the ability of the healthy elderly to initiate and maintain sleep, accompanied by a decrease in the proportion of the deeper, more restorative slow-wave sleep and rapid eye movement sleep. There is epidemiologic evidence that this impaired ability to initiate, maintain, and ultimately achieve good quality, optimal sleep may be a marker of increased mortality and neurocognitive dysfunction. Possible mechanisms related to these age-related changes in sleep include age-related changes in circadian modulation, homeostatic factors, cardiopulmonary function, and endocrine function. This article describes the normal changes in sleep physiology in the elderly.

Pulmonary hypertension due to a retained totally implantable venous access device fragment.

Pulmonary hypertension can occur from obstruction of the distal pulmonary arteries by thrombus, ova and parasites, and foreign material. We report a 62-year-old patient who had fatal pulmonary hypertension from an 8-cm fragment of a totally implantable venous access device (TIVAD) retained in the pulmonary artery. Despite long-term therapeutic anticoagulation, pulmonary angiography showed chronic occlusion of the posterior branch of the superior right pulmonary artery with paucity of distal vasculature consistent with an old right upper lobe pulmonary embolus. Retrieval of the fragment was attempted via pulmonary artery catheterization techniques but was unsuccessful. In conclusion, progressive pulmonary hypertension may result from retention of a TIVAD fragment in a central pulmonary artery despite therapeutic anticoagulation. Worsening pulmonary hypertension may have been due to partial obstruction of the main pulmonary arteries, resulting in recurrent thromboembolism or in situ thrombosis, and remodeling of small distal pulmonary arteries.

Fatal tumor thrombosis due to an inferior vena cava leiomyosarcoma in a patient with antiphospholipid antibody syndrome.

We describe a patient with antiphospholipid antibody syndrome (APS) who died because of relentless inferior vena cava (IVC) tumor thrombosis due to an unsuspected leiomyosarcoma. Laboratory confirmation for APS was provided by functional identification of a lupus anticoagulant and anticardiolipin IgG and anti-beta2-glycoprotein I IgM antibodies. Although sensitive for detecting vascular obstruction, radiocontrast venography and magnetic resonance imaging and angiography detected the IVC thrombosis but failed to distinguish its malignant nature. Concomitant refractory thrombocytopenia prevented further invasive diagnostic and therapeutic maneuvers for progressive, severe IVC thrombosis unresponsive to aggressive treatment of APS. Deep venous thrombosis refractory to anticoagulant and immunomodulatory therapies in a patient with APS may be due to a concomitant underlying malignancy, such as a leiomyosarcoma, causing vascular obstruction.