Subpleural sparing: Clinical, physiological, and radiological implications

The term "subpleural sparing" refers to computed tomography (CT) images that indicate that there is limited disease/infiltrate in the immediate subpleural location. This observation is often associated with nonspecific interstitial pneumonitis and is a characteristic that distinguishes this pathology from usual interstitial pneumonitis (idiopathic pulmonary fibrosis). Subpleural sparing can also occur in acute respiratory disorders, including pulmonary contusion in children, acute lung disease associated with electronic cigarettes (vaping), and aspiration of exogenous lipids. Potential explanations for this observation include nonuniform distribution of lung injury/inflammation, nonuniform clearing/resolution of injury, and variations in CT image acquisition and presentation. The subpleural region contains lymphatic structures on the interior surface of the visceral pleura and in interlobular septa. The density of subpleural lymphatics decreases in more interior zones of the lung that largely contain alveolar-capillary units. These lymphatics transfer fluid and other inflammatory mediators from the peripheral lung into central lymphatics and veins. Consequently, the density and distribution of lymphatics could explain preferential clearing of the subpleural regions during acute injury. The acquisition of CT images also depends on the configuration of detectors, slice thickness, and the energy of the electron beam. Clinicians should carefully consider the disease process, lymphatic function and other clearance mechanisms, and the vagaries in CT image acquisition when they evaluate patients with subpleural sparing.

Does Fluid Administration Based on Fluid Responsiveness Tests such as Passive Leg Raising Improve Outcomes in Sepsis?

The management of sepsis requires the rapid administration of fluid to support blood pressure and tissue perfusion. Guidelines suggest that patients should receive 30 ml per kg of fluid over the first one to three hours of management. The next concern is to determine which patients need additional fluid. This introduces the concept of fluid responsiveness, defined by an increase in cardiac output following the administration of a fluid bolus. Dynamic tests, measuring cardiac output, identify fluid responders better than static tests. Passive leg raising tests provide an alternative approach to determine fluid responsiveness without administering fluid. However, one small randomized trial demonstrated that patients managed with frequent passive leg raising tests had a smaller net fluid balance at 72 hours and reduced requirements for renal replacement therapy and mechanical ventilation, but no change in mortality. A meta-analysis including 4 randomized control trials reported that resuscitation guided by fluid responsiveness does not improve mortality outcomes in patients with sepsis. Recent studies have demonstrated that the early administration of norepinephrine may improve outcomes in patients with sepsis. The concept of fluid responsiveness helps clinicians analyze the clinical status of patients, but this information must be integrated into the overall management of the patient. This review considers the use and benefit of fluid responsiveness tests to direct fluid administration in patients with sepsis.

High prevalence of non-thyroidal illness syndrome in patients at long-term care facilities

PURPOSE

Patients in acute care hospitals are often transferred to long-term care (LTC) when there is an expectation for a lengthy recovery. Prolonged non-thyroidal illness syndrome (NTIS) creates a state of hypothyroidism. We aimed to investigate the prevalence of NTIS in patients at LTC facilities.

METHODS

A cross-sectional study at University Hospitals and Rehabilitation and Skilled Nursing facility was performed. Four groups: control (n:33), intensive care unit (ICU) (n:34), long-term care hospital (LTCH) (n:50), and long-term care on chronic ventilatory support (LTCVS) (n:30). Serum levels of TSH, free T4 (FT4), free T3 (FT3), and interleukin 6 (IL6) measured at admission day in controls, within 48 h of admission in the intensive care group, between days 31 and 120 in the LTC hospital group and days 31 and 6 years in the LTC on chronic ventilatory support group.

RESULTS

Serum FT3 levels were lower in groups intensive care unit ICU, LTCH, and LTCVS than control. Low serum FT3 levels were observed in 80% ICU, 54% LTCH, 37% LTCVS, and 6% control patients. Low serum FT4 levels were observed in 32% ICU, 16% LTCH, and 20% LTCVS patients. Both low serum FT4 and FT3 levels were observed in 32% ICU, 16% LTCH, and 13% LTCVS patients. Serum IL6 and FT3 levels showed a negative correlation.

CONCLUSIONS

NTIS is highly prevalent in patients in LTC, creating a state of persistent hypothyroidism. The effects of thyroid hormone replacement in patients at LTC with non-thyroidal illness deserve further investigation.

Analysis of Glucose Levels in Patients Hospitalized With COVID-19 During the First Phase of This Pandemic in West Texas

Background:

Patients with hyperglycemia during hospitalization, especially during ICU hospitalizations, often have worse outcomes, even if they do not have a premorbid diagnosis of diabetes. High glucose levels can provide insight into the underlying pathogenesis of a disease and can contribute to tissue injury. Some patients with COVID-19 have hyperglycemia during hospitalizations.

Methods:

The Infectious Disease and Control office at University Medical Center in Lubbock, Texas, provided a list of patients with a COVID-19 infection hospitalized between March 1 and May 15, 2020. The medical records were reviewed to collect information on age, gender, history of diabetes, and glucose levels on admission and through the first 7 days of hospitalization.

Results:

This study included 63 patients with a mean age of 62.1 ± 14.1 years. Thirty-five patients (55.6%) were males. The in-hospital mortality rate was 30.2%. The mean admission glucose level was 129.4 ± 57.1 mg/dL in patients who survived (N = 47) and 189.6 ± 112.2 mg/dL in patients who died during hospitalization (N = 16, P = .007). An admission glucose greater than 180 mg/dL predicted mortality in a model adjusted for a diabetes, age, and male gender. The mean differences between the maximum and minimum glucose levels calculated over the first 7 days of hospitalization were 112.93 ± 115.4 (N = 47) in patients who survived and were 240.5 ± 97.7 (N = 15) in patients who died during hospitalization (P = .0003). A difference between the maximum and minimum glucose level greater than 105 mg/dL was associated with increased mortality.

Conclusions:

Patients who died during hospitalization for COVID-19 had higher admission glucose levels than patients who survived. Larger differences between maximum and minimum glucose levels during the first 7 days of hospitalization were associated with increased mortality. These results suggest that high glucose levels identify patients at increased risk for mortality and warrant more study.

A Retrospective Analysis and Comparison of Prisoners and Community-Based Patients with COVID-19 Requiring Intensive Care During the First Phase of the Pandemic in West Texas

Background:

COVID-19 is a highly infectious disease which usually presents with respiratory symptoms. This virus is disseminated through respiratory droplets, and, therefore, individuals residing in close quarters are at a higher risk for the acquisition of infection. The prison population is at a significantly increased risk for infection.

Methods:

Prisoners from the Montford Correctional facility in Lubbock, Texas, hospitalized in the medical intensive care unit at University Medical Center between March 1, 2020 and May 15, 2020 were compared to community-based patients hospitalized in the same medical intensive care unit. Clinical information, laboratory results, radiographic results, management requirements, and outcomes were compared.

Results:

A total of 15 community-based patients with a mean age of 67.4 ± 15.5 years were compared to 5 prisoners with a mean age of 56.0 ± 9.0 years. All prisoners were men; 10 community-based patients were men. Prisoners presented with fever, dyspnea, and GI symptoms. The mean number of comorbidities in prisoners was 2.4 compared to 1.8 in community-based patients. Prisoners had significantly lower heart rates and respiratory rates at presentation than community-based patients. The mean length of stay in prisoners was 12.6 ± 8.9 days; the mean length of stay in community-based patients was 8.6 ± 6.5. The case fatality rate was 60% in both groups.

Conclusions:

Prisoners were younger than community-based patients but required longer lengths of stay and had the same mortality rate. This study provides a basis for comparisons with future studies which could involve new treatment options currently under study.

Clinical entities, phenotypes, causation, and endotypes based on selected asthma publications

Patients with complex chronic disorders, such as asthma, present clinicians with important management problems. The identification of a clinical syndrome usually leads to the diagnosis of the disease entity. The next concern involves classification and a choice as to whether to use a few inclusive categories or multiple exclusive categories. Patients with asthma have multiple clinical syndromes, and these can be described as phenotypes. The use of cluster analysis allows investigators to identify phenotypes with less clinical bias. However, the identification of a particular phenotype does not necessarily provide much insight into the underlying pathogenesis. In asthma, the pathogenetic events are complex and multiple and require a classification based on endotypes. This difficulty introduces the idea of causation and models for causation. Asthma probably does not have a single universal necessary cause. However, it does have multiple sufficient component causes. Understanding these components and their interactions potentially leads to better treatment trials and more focused drug therapy. Clinicians need to identify asthmatic patients and classify them into particular phenotypes; they should also wonder about causation. Clinical investigators need to use these phenotypes to identify more homogenous groups of patients to study the underlying pathogenesis and establish endotypes. Focusing on causation can improve our understanding of disease entities, disease classification, and disease causation. This review outlines ideas relevant to causation in nearly all diseases.

Prevalence of Coronavirus Antibody Among First Responders in Lubbock, Texas

BACKGROUND

The ongoing coronavirus disease (COVID-19) pandemic has a major impact on first responders. Scarce personal protective equipment (PPE) has forced them to conserve and reuse some of their PPE. The efficacy of these practices in preventing transmission of COVID-19 from patients to first responders is unclear. There are limited data on the prevalence of antibodies specific for COVID-19 exposure in these front-line workers.

AIM

Our objective was to determine the prevalence of positive immunoglobulin G antibody specific to COVID-19 among first responders in Lubbock, Texas.

METHODS

Blood samples were collected on 683 asymptomatic first responders who work in Lubbock, Texas and the surrounding area, after informed consents were signed. IgG antibody to SARS-CoV-2 was measured using Abbott's SARS-CoV-2 IgG Reagent Kit in combination with the SARS-CoV-2 IgG Calibrator Kit on the Abbott's ARCHITECT i1000SR analyzer.

RESULTS

The prevalence of IgG specific antibodies to COVID-19 was 0.73%, five of the 683 participants tested positive. Four of those who tested positive had no known prior SARS-CoV-2 infection or exposure without adequate PPE.

CONCLUSIONS

The prevalence of IgG specific antibodies to COVID-19 was much lower than expected in our study population despite high sensitivity and specificity of the test reagent. The most likely explanations for this finding include limited exposure, inadequate time for a IgG response, possible clearance of COVID-19 infection locally by the respiratory tract IgA defense system without eliciting a systemic IgG response, and short persistence of IgG antibodies in mild or asymptomatic cases.

RETRACTED: Basic Demographic Parameters Help Predict Outcomes in Patients Hospitalized With COVID-19 During the First Wave of Infection in West Texas

The severity of COVID-19 ranges from asymptomatic subclinical infections to severe acute respiratory failure requiring mechanical ventilation. Patients admitted to the hospital have increased mortality rates and patients requiring intensive care have significantly increased mortality rates. Multiple factors influence these outcomes. This study used simple demographic information available on admission to evaluate possible associations between these variables and outcomes, including mortality and length of stay. Clinical outcomes in 63 patients admitted to a tertiary care hospital in West Texas were reviewed. Older patients, patients admitted from nursing homes, and patients admitted to medical intensive care units had increased mortality. Unadjusted analysis indicated that males had increased mortality. Adjusted analysis indicated that males spent nearly 5 days longer in the hospital than females. In summary, age, chronic illness requiring nursing home placement, and acute severe illness requiring intensive care unit admission identify patients with worse prognoses. In addition, males will likely have a longer length of hospital stay.

The undead in culture and science

The undead have a significant role in mythology, religion, folklore, and literature. In the 1800s, the word zombie was used to describe reanimated corpses in the Caribbean who often worked on plantations doing long, arduous field work. The movie White Zombie was released in 1932 and exploited this folklore, but it ignored the fact that zombies represent one outcome in Vodou religious beliefs regarding death and the migration of spirits following death. The interest in zombies eventually led to sociological and medical investigations into zombification. Wade Davis reported that powders used by malevolent priests (bokors) contained tetrodotoxin, which could cause the neurologic changes underlying the zombie phenotype. Recent clinical studies have indicated that synthetic cannabinoids and synthetic cathinones can cause bizarre zombie-like behavior. According to Haitian folklore, zombies can develop when bokors reanimate someone who suddenly died from an acute illness or who was purposely poisoned. Recent studies in molecular biology suggest that the sequence of programmed cell death can be reversed when the stressor is removed and that cells, tissues, and bodies (at least in Drosophila flies) can recover. These scientific studies would support the remote possibility that the near dead might recover under certain circumstances but have residual neuropsychological dysfunction. Alternatively, the bokors could maintain control of their victims using drugs with properties similar to those of synthetic cannabinoids. The concept of zombification needs to be considered in the context of culture, religion, and science.

Is the sinonasal questionnaire a useful screening instrument for chronic sinonasal diseases in pulmonary clinics?

Dixon and coworkers (Dixon AE, Sugar EA, Zinreich SJ, et al. Criteria to screen for chronic sinonasal disease. Chest 2009; 136: 1324-1332.) recently developed a five-item questionnaire for diagnosing chronic sinonasal disease in patients with asthma. Our study was designed to determine how frequently patients attending pulmonary clinics have chronic sinonasal disease and the relationship between questionnaire results and a history of sinus disease and current treatment for sinus disease. The participants were patients in pulmonary clinics at Texas Tech University Health Science Center, who answered the sinonasal questionnaire (SNQ). Additional information included a history of sinus disease or sinus/nasal surgery, smoking status, and current relevant medications. The participants included 28 men and 51 women. Patient ages ranged from 38 to 94 years (mean 62.2 years). Of all the patients, 28 patients (35.4%) had prior sinus disease, 10 (12.7%) had history of sinus or nasal surgery, 24 (30.4%) had history of asthma, and 10 (12.7%) were current smokers. Of them, 14 patients (17.7%) used nasal steroids, 12 (15.2%) used antihistamines, four (5.1%) used decongestants, nine (11.4%) used leukotriene inhibitors, 13 (16.5%) used oral corticosteroids, and two (2.5%) used combinations. The SNQ identified 39 patients (49.4%) as having chronic sinonasal diseases. Therefore, 14% of the participants had sinonasal symptoms but no prior diagnosis of sinus disease. Patients with prior sinus disease and nasal steroid use were more likely to have positive questionnaire result (p<0.001 and p<0.032, respectively). The SNQ can identify patients with chronic sinonasal disease in pulmonary clinics. However, the significance of sinonasal disease and its treatment in these patients needs more study.