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October 2016 - present
Publications
Publications (135)
Obesity and certain craniofacial features are known anatomic risk factors for obstructive sleep apnea (OSA) [1–3]. Prior studies also show that several physiological traits (termed endotypes) contribute to the development of the repetitive upper airway obstructions during sleep that characterizes OSA [4]. Four major OSA physiological traits have be...
Importance
One mechanism for teenagers’ elevated crash risk during independent driving may be inadequate learner driving experience.
Objective
To determine how learner driver experience was associated with crash risk during the first year of independent driving.
Design, Setting, and Participants
Youth aged 15.5 to 16.1 years at recruitment were e...
The objective of this study was to describe trends in the prevalence of opioids in driver fatalities and examine geographic variation in opioid-involved crashes at a county level. Using comprehensive toxicological data from the Office of the Chief Medical Examiner in Maryland, we examined the prevalence of opioids in all motor vehicle crash fatalit...
Rationale: Patients managed at a long-term acute-care hospital (LTACH) for weaning from prolonged mechanical ventilation are at risk for profound muscle weakness and disability. Objectives: To investigate effects of prolonged ventilation on survival, muscle function, and its impact on quality of life at 6 and 12 months after LTACH discharge. Method...
An increasing number of countries are requiring an extended learner permit prior to independent driving. The question of when drivers begin the learner permit period, and how long they hold the permit before advancing to independent licensure has received little research attention. Licensure timing is likely to be related to “push” and “pull” facto...
Rationale:
More than a million polysomnograms (PSGs) are performed annually in the United States to diagnose obstructive sleep apnea (OSA). Third-party payers now advocate a home sleep test (HST), rather than an in-laboratory PSG, as the diagnostic study for OSA regardless of clinical probability, but the economic benefit of this approach is not k...
Rationale:
Respiratory pathogens are frequently isolated from the airways of patients with chronic obstructive pulmonary disease (COPD) in the absence of an exacerbation. This bacterial "colonization" by potential pathogens is associated with host inflammatory and immune responses, which could increase respiratory symptoms.
Objectives:
To study...
Importance Patients requiring prolonged mechanical ventilation (>21 days) are commonly weaned at long-term acute care hospitals (LTACHs). The most effective method of weaning such patients has not been investigated.
Objective To compare weaning duration with pressure support vs unassisted breathing through a tracheostomy collar in patients transfer...
Objective
Autotitrating continuous positive airway pressure (auto-CPAP) devices now have a smart card (a pocket-sized card with embedded integrated circuits which records data from the CPAP machine such as CPAP usage, CPAP pressure, large leak, etc.) which can estimate the Apnea–Hypopnea Index (AHI) on therapy. The aim of this study was to determin...
The purpose of the study was to determine if the adverse effect of body position on obstructive sleep apnea (OSA) is worsened during rapid eye movement (REM) sleep and if patients with OSA decrease the time spent supine during REM sleep.
Overnight polysomnography from 80 sequential patients referred to Buffalo VA Sleep Lab for suspected OSA were an...
Objective:
Animal models have shown a quantal slowing of respiratory pattern when exposed to opioid agonist, in a pattern similar to that observed in central sleep apnea. We postulated that opioid-induced hypoventilation is more likely to be associated with sleep apnea rather than hypoventilation alone. Since we did not have a direct measure of hy...
Objectives:
Three cases are presented in which patients were using opioids as required for nonmalignant pain management and significant central sleep apnea developed. Patients in the first two cases had no evidence of sleep-related breathing disorders on polysomnography until they ingested an opioid for treatment of chronic pain during the night a...
The international migration of physicians is a global public health problem. Lebanon is a source country with the highest emigration factor in the Middle East and North Africa and the 7th highest in the World. Given that residency training abroad is a critical step in the migration of physicians, the objective of this study was to survey students o...
Characteristics of Lebanese medical school
Survey questionnaire
Only 30% to 50% of people produce the daidzein-metabolite equol after eating soy. We conducted a cross-sectional study of the associations between equol status, intake of soy foods, and mammographic density in a sample of postmenopausal women recruited at a radiology clinic near Buffalo, New York. Participants were 48 to 82 years old, had no histor...
Increased bacterial concentration (load) in the lower airways and new bacterial strain acquisition have been posited as mechanisms for chronic obstructive pulmonary disease (COPD) exacerbations. Bacterial concentrations are higher during exacerbation than during stable disease; however, these studies are cross sectional and devoid of strain typing....
Mathematical formulas have been less than adequate in assessing the optimal continuous positive airway pressure (CPAP) level in patients with obstructive sleep apnea (OSA). The objectives of the study were (1) to develop an artificial neural network (ANN) using demographic and anthropometric information to predict optimal CPAP level based on an ove...
To assess the relation between medications prescribed for chronic pain and sleep apnea.
An observational study of chronic pain patients on opioid therapy who received overnight polysomnographies. Generalized linear models determined whether a dose relation exists between methadone, nonmethadone opioids, and benzodiazepines and the indices measuring...
There are data about the relationship between morphologic findings on high-resolution computed tomography (HRCT) and the number of acid-fast bacilli (AFB) on sputum smears in patients with pulmonary tuberculosis (PTB). It was also shown that existence of cavities and airspace consolidation might be related to smear positivity in PTB patients. Howev...
The DA Structure. Describes the structure of the Decision Aid.
Inhaled steroids in COPD patients' specific Knowledge scale. Reproduces the Inhaled steroids in COPD patients' specific Knowledge scale
Decision aids (DA) are tools designed to help patients make specific and deliberative choices among disease management options. DAs can improve the quality of decision-making and reduce decisional conflict. An area not covered by a DA is the decision of a patient with chronic obstructive pulmonary disease (COPD) to use inhaled steroids which requir...
To determine if obesity-related changes in lung volume might contribute to airway reactivity, we investigated the effects of simulated mild obesity-related lung volume reductions on airway responsiveness in lean, nonasthmatic subjects. Participants and methods: We simulated the lung volume reductions of class 1 obesity in eight lean, nonasthmatic s...
Several studies investigated the association of anemia with health related quality of life (HRQL) in patients with chronic disease. However, there is little evidence regarding the association of anemia with HRQL in patients with chronic obstructive pulmonary disease (COPD).
This is a post-hoc analysis of a study which enrolled a population of adult...
Current recommendations for management of obese patients post-extubation are based on clinical experience and expert opinions. It was hypothesised that the application of noninvasive ventilation (NIV) during the first 48 h after extubation in severely obese patients would reduce post-extubation failure and avert the need for reintubation.
Following...
Residency training programs use the night float system increasingly to meet the new resident work hour regulations.
To assess and compare residents', attendings', and nurses' perceptions of the night float system.
A survey study.
One hundred and seven residents, 48 attendings, and 69 nurses in a university-based multicenter internal medicine reside...
The prevalence of obesity is increasing, and there is evidence that obesity, in particular abdominal obesity as a marker of insulin resistance, is negatively associated with pulmonary function. The mechanism for this association and the best marker of abdominal adiposity in relation to pulmonary function is not known.
We assessed the association be...
Studies have shown increased oxidative stress in patients with chronic airflow limitation; however, the population-based evidence
for the association of oxidative stress with pulmonary function is limited. The authors analyzed the association of plasma
thiobarbituric acid-reactive substances (TBARS), glutathione, glutathione peroxidase, and 6-hydro...
Breastfeeding reduces the risk of asthma and respiratory infections in infants. Since respiratory infections are associated with reduced pulmonary function in adolescents, pulmonary function impairment may be carried into adulthood. Our aim was to determine whether a history of having been breastfed as an infant is a determinant of adult pulmonary...
The primary aim of this study was to determine the prevalence of positional obstructive sleep apnea using a functional definition. Positional sleep apnea was defined as a total apnea-hypopnea index (AHI) > or = 5 with a > 50% reduction in the AHI between the supine and nonsupine postures, and an AHI that normalizes (AHI < 5) in the nonsupine postur...
Moraxella catarrhalis is frequently present in the sputum of adults with chronic obstructive pulmonary disease (COPD). Little is known about the role of M. catarrhalis in this common disease.
To elucidate the burden of disease, the dynamics of carriage, and immune responses to M. catarrhalis in COPD.
Prospective cohort study of 104 adults with COPD...
Several variables are recommended for identifying if a patient is ready for a trial of weaning from mechanical ventilation, but there is no agreement as to whether monitoring any variable during the trial enhances patient management. To determine whether repeated measurements of esophageal pressure throughout a trial are more reliable than measurem...
The original chronic respiratory questionnaire (CRQ), one of the most widely used measures of health-related quality of life (HRQL) in chronic respiratory disease (CRD), is traditionally interviewer administered (IA) and includes an individualised dyspnoea domain. The present authors studied the impact of self-administered (SA) and standardised dys...
The effects of [+/-]-2,5-dimethoxy-4-iodoaminophentamine, a serotonin(2A/2C) receptor agonist, on pharyngeal airflow mechanics were examined in isoflurane-anesthetized lean and obese Zucker rats. The pharyngeal pressure associated with flow limitation, maximum inspiratory flow, oronasal resistance, genioglossus muscle activity, and arterial blood p...
Individuals with cystic fibrosis (CF) have large amounts of infected mucus in their lungs, which causes irreversible lung tissue damage. Although patient-administered positive expiratory pressure (PEP) breathing has been promoted as an effective therapeutic modality for removing mucus and improving ventilation distribution in these patients, the ef...
Previous studies of immune response to Haemophilus influenzae after exacerbations of chronic obstructive pulmonary disease (COPD) have yielded contradictory results. Using homologous (infecting) strains and immunoassays to surface-exposed epitopes, we tested the hypothesis that adults with COPD make new antibodies to strain-specific, surface-expose...
s: To compare the relative usefulness of the different indexes derived from pulse oximetry in the diagnosis of obstructive sleep apnea (OSA), and to determine if a combination of these indexes improves the prediction of the apnea-hypopnea index (AHI) measured by polysomnography.
Prediction model developed from 224 patients, validated prospectively...
Quality control in the clinical pulmonary function laboratory has been well developed for spirometry and diffusing capacity but not for the measurement of TLC. The purpose of the present study was to test two approaches to this problem. First, we compared TLC by body plethysmography (TLCb) with a value predicted from TLC measured by multibreath hel...
Pulmonary function is dependent not only on smoking, but also on nutritional status. Since an increased RBC distribution width (RDW) has been associated with nutritional deficiencies, we postulated that RDW has an inverse relation to pulmonary function. The purpose of this study was to test this hypothesis.
A cross-sectional study was conducted of...
Lung function is a strong predictor of cardiovascular and all-cause mortality. Previous studies suggest that alcohol exposure may be linked to impaired pulmonary function through oxidant-antioxidant mechanisms. Alcoholic beverages may be an important source of oxidants and antioxidants. We analyzed the relation of beverage-specific alcohol intake w...
There is some evidence that glucose and other factors related to glucose metabolism, such as insulin and insulin-like growth-factors (IGFs) may contribute to breast cancer development. The present study analyzed the hypothesis that serum glucose, insulin levels, and IGF-I pattern are associated with breast cancer using a nested case-control study....
Context
Private for-profit and private not-for-profit dialysis facilities provide
the majority of hemodialysis care in the United States. There has been extensive
debate about whether the profit status of these facilities influences patient
mortality.Objective
To determine whether a difference in adjusted mortality rates exists
between hemodialys...
CONTEXT. Private for-profit and private not-for-profit dialysis facilities provide the majority of hemodialysis care in the United States. There has been extensive debate about whether the profit status of these facilities influences patient mortality.
OBJECTIVE. To determine whether a difference in adjusted mortality rates exists between hemodia...
Private for-profit and private not-for-profit dialysis facilities provide the majority of hemodialysis care in the United States. There has been extensive debate about whether the profit status of these facilities influences patient mortality.
To determine whether a difference in adjusted mortality rates exists between hemodialysis patients receivi...
The role of bacterial pathogens in acute exacerbations of chronic obstructive pulmonary disease is controversial. In older studies, the rates of isolation of bacterial pathogens from sputum were the same during acute exacerbations and during stable disease. However, these studies did not differentiate among strains within a bacterial species and th...
The purpose of this work was to study the impact of a patient-self-completed history questionnaire upon the quality of the information in the medical record, resource utilization, patient satisfaction, and physician satisfaction. A controlled trial was performed in a primary care clinic of a public supported, urban, university hospital. The patient...
Elevated plasma endothelin-1 (ET-1) levels have been reported in association with hypoxia and congestive heart failure (CHF). Furthermore, Cheyne-Stokes respiration-central sleep apnea (CSR-CSA) has been found to correlate with the degree of pulmonary hypertension and the severity of CHF; however, the association between ET-1 levels and CSR-CSA has...
Canadians are engaged in an intense debate about the relative merits of private for-profit versus private not-for-profit health care delivery. To inform this debate, we undertook a systematic review and meta-analysis of studies comparing the mortality rates of private for-profit hospitals and those of private not-for-profit hospitals.
We identified...
It has been suggested that obstructive sleep apnea (OSA)-induced hypoxic stress might contribute to cardiovascular disorders by promoting expression of soluble adhesion molecules. The reported increase of circulating adhesion molecules in patients with OSA remains controversial because confounders such as cardiovascular risk factors and left ventri...
Lung function is a strong predictor of cardiovascular and all-cause mortality. Previous studies suggest that alcohol exposure may be linked to impaired pulmonary function through oxidant-antioxidant mechanisms. Alcohol may be an important source of oxidants; however, wine contains several antioxidants. In this study we analyzed the relation of beve...
Accumulating evidence suggests that dietary antioxidant vitamins are positively associated with lung function. No evidence exists regarding whether dietary carotenoids other than beta-carotene are related to pulmonary function. In 1995--1998 the authors studied the association of forced expiratory volume in 1 second and forced vital capacity as the...
Less than one third of patients with fatal pulmonary embolism (PE) are identified prior to autopsy.
To determine whether the clinical syndromes of acute PE are effective at identifying patients who die of this condition.
Seven hundred seventy-eight autopsy reports at the Buffalo General Hospital from 1991 to 1996 inclusive were reviewed. Inpatient...
Reduced pulmonary function is an important predictor of mortality in the general population, and antioxidant vitamins are thought to positively influence pulmonary function. Vitamin C, vitamin E, retinol, and carotenoids are powerful antioxidants but information about the joint relation of serum levels of these antioxidants to pulmonary function is...
The etiologic role of bacterial pathogens isolated from sputum culture in 40 to 50% of acute exacerbations of chronic bronchitis (AECB) is controversial. If bacterial pathogens cause these AECB, they should be associated with greater neutrophilic airway inflammation than pathogen-negative exacerbations.
This hypothesis was tested by comparing level...
Results from several studies have described a relationship between pulmonary function and both all-cause and cause-specific mortality. The purpose of this study was to investigate the predictive value of pulmonary function by gender after 29 years of follow-up.
Prospective study with 29-year follow-up of the Buffalo Health Study cohort.
Randomly se...
Nosocomial outbreaks of tuberculosis (TB) have been attributed to unrecognized pulmonary TB. Accurate assessment in identifying index cases of active TB is essential in preventing transmission of the disease.
To develop an artificial neural network using clinical and radiographic information to predict active pulmonary TB at the time of presentatio...
To evaluate the predictive accuracy of the severity of illness scoring systems in a single institution.
A prospective study conducted by collecting data on consecutive patients admitted to the medical intensive care unit over 20 months. Surgical and coronary care admissions were excluded.
Veterans Affairs Medical Center at Buffalo, New York.
Data c...
Clinical assessment of obstructive sleep apnea (OSA) is poor. Overnight polysomnography (OPG) is the standard reference test, but it is expensive and time-consuming. We developed an artificial neural network (ANN) using anthropomorphic measurements and clinical information to predict the apnea-hypopnea index (AHI). All patients completed a question...
To determine the clinical and radiographic findings of nontuberculous mycobacteria (NTM) other than Mycobacterium avium complex (MAC) and Mycobacterium kansasii in AIDS compared with non-AIDS patients.
A retrospective chart review of all patients in whom NTM other than MAC complex and M kansasii were isolated between April 1, 1989, and October 31,...
Dysrhythmias of breathing occur in several clinical disorders, but their mechanistic basis is obscure. To understand their pathophysiology, factors responsible for the variability of breathing need to be defined. We studied the effect of hyperoxic hypercapnia (CO2) on the variational activity of breathing in 14 volunteers before and after deliverin...
The recent outbreaks of multidrug-resistant strains of M. tuberculosis in health care facilities has increased concern over its transmission in health care facilities. Isolation has been recommended for all patients suspected to have tuberculosis even though the feasibility and the cost of this recommendation can be substantial. We have developed a...
To evaluate the predictive ability of three scoring systems, acute physiology and chronic health evaluation (APACHE II), simplified acute physiology score (SAPS II), and mortality probability models (MPM II) in critically ill obstetric patients compared to a control group of non-obstetric female patients of similar age group (range, 17 to 41 years)...
Mechanical ventilatory support (VS) is often required for patients with AIDS. Patients, and/or their surrogates often ask the likely outcome of this intervention. To answer this question, we have developed a classification tree using clinical data from 71 patients with AIDS identified from the discharge abstracts of two hospitals between January 19...
The length of time that blood remains in the pulmonary capillary is an important variable in gas exchange. We have investigated the distribution of capillary transit times in isolated rabbit lungs perfused with a bicarbonate-free buffer. The time course of gas exchange was monitored by enclosing the lungs in a plethysmograph. A bolus of buffer cont...
Wavelet decomposition is proposed as a novel approach for determining pulmonary arterial input impedance throughout the breathing cycle. The canine pulmonary arterial input impedance was evaluated throughout the ventilatory cycle at 5, 10, and 15 cmH2O of positive end-expiratory pressure. The impedance spectrum was obtained by Fourier transformatio...
The gas exchange threshold (GET) has been used an an index of anaerobic threshold because it can be measured noninvasively. GET is estimated from a breakpoint in breath by breath values of carbon dioxide uptake (Vco2) and oxygen uptake (Vo2) obtained during a progressive exercise test. Three methods of estimating GET were evaluated: (1) the origina...
We tested the hypothesis that pulmonary arterial input impedance varies during the ventilatory cycle due to alterations not only of the viscoelastic components of the pulmonary vasculature but also due to changes of the inertial components. A four-element lumped-parameter model was used to fit the pulmonary arterial pressure-flow recordings in the...
We measured the relationship between pulmonary arterial pressure (Ppa), diameter (D), and length of a segment of the main pulmonary artery (MPA) in chronically instrumented conscious dogs breathing spontaneously (CCC). There were no physiologically significant changes in Ppa or D in the CCC dogs postoperatively, and the cross-sectional MPA shape me...
Transmural pulmonary arterial pressure (Ppa), diameter (D), and length (L) of a segment of the main pulmonary artery (MPA) were measured simultaneously in anesthetized open-chest dogs. The instantaneous volume was calculated from D and L. Pulmonary arterial elasticity for diameter (EpD) was calculated as the ratio of the amplitude of Ppa to D oscil...
This study compares the independent effects of flow (Qpa) and transmural pressure (Ppa) on the diameter (D) and length of a segment (L) of the main pulmonary artery (MPA) in anesthetized open-chested dogs. Qpa was increased by a shunt from the left lower lobe pulmonary artery to an external jugular vein. Ppa was increased with positive end-expirato...
We tested the hypothesis that pulmonary arterial compliance (Ca) varies during the ventilatory cycle. Pressure and flow in the main pulmonary artery were measured in open-chest dogs under chloralose anesthesia (n = 12) with a positive-pressure volume-cycled ventilator. Input impedance was calculated from the pressure and flow waves of heart cycles...
Ventilatory requirements using high-frequency oscillation (HFO) during simulated altitude exposure were investigated in control dogs and animals with oleic acid-induced lung injury. FIO2 values of 0.21 and 1.0 were supplied by bias flow to the normal and injured dogs, respectively. After a control period, animals were exposed to a simulated altitud...
The influence of molecular diffusion on gas-mixing during conventional mechanical ventilation (CMV) and high frequency ventilation (HFV) was studied by observing the wash-in of six poorly soluble, inert gases in arterial blood. Anesthetized dogs were ventilated either with CMV or HFV. Following a step change in inspired gas composition, the increas...
We compared the effects of three forms of vascular obstruction: positive end-expiratory pressure (PEEP), ensnarement of the left main pulmonary artery (SN), and pulmonary thromboembolism (EMB) on right ventricular afterload. We measured right ventricular and pulmonary arterial pressures and flow in open-chested dogs under anesthesia (n = 8). Pulmon...
Page H587: B. J. B. Grant and L. J. Paradowski. “Characterization of pulmonary arterial input impedance with lumped parameter models.” Equations 5 and 6 should appear as the following.
(See PDF)
Page H587: B. J. B. Grant and L. J. Paradowski. “Characterization of pulmonary arterial input impedance with lumped parameter models.” Equations 5 and 6 should appear as the following.
(See PDF)
The purpose of this study was to test the hypothesis that there is a direct relation between pulmonary arterial input resistance and compliance in seven anesthetized cats. Cardiac output was altered by varying the direction and flow through an arteriovenous fistula with a roller pump. Pulmonary arterial input impedance was calculated from the Fouri...
The purpose of this study was to investigate the mechanism that causes a damped oscillatory response of local pulmonary blood flow to local hypoxia. The left lower lobe (LLL) of 10 anesthetized dogs was ventilated independently but synchronously with the rest of the lungs. Blood flow to the LLL as a proportion of total flow (QLLL/QT) was measured d...
High - frequency ventilation (HFV) is a promising mode of ventilatory support and could be useful in aeromedical evacuation. There have been no studies to date to examine the feasibility of maintaining gas exchange with HFV at reduced barometric pressure. This report investigates (1) The role of molecular diffusion in gas transport during HFV, and...
We determined the effect of perivascular electromagnetic flow probes (EMF) on pulmonary hemodynamics in acute experiments. In seven dogs placement of the EMF on the main pulmonary artery (MPA) increased pulmonary arterial pulse pressure by 25% (17.8-21.9 cmH2O, P less than 0.005) and mean right ventricular pressure by 12% (23.2-25.9 cmH2O, P less t...
Many patients with chronic obstructive pulmonary disease (COPD) receiving supplemental oxygen state that this treatment makes them less short of breath at rest. We postulated that this phenomenon may be related to improved arterial oxygenation, reduced ventilation, or stimulation of nasal receptors caused by the flow of gas. Eight patients who repo...
