Scott Ryals

Appropriate use of myocardial perfusion imaging in a veteran population: profit motives and professional liability concerns.

calate niacin use, specifically Niaspan in the United States, with its prominent “intervention-style” ads.11 Our study is limited in that we did not have access to patient-level data to determine whether niacin prescribing was clinically appropriate. Our study only evaluated the prescription niacin market; niacin use likely exceeds our estimates since some niacin products can be purchased over the counter. In conclusion, our study shows that prescription niacin sales are substantial and growing, even in the absence of contemporary supportive trial evidence. The discordance between sales and evidence should be a focus of professional dialogue about the role of this medication in the medical armamentarium.

Clinical utility of inappropriate positron emission tomography myocardial perfusion imaging: Test results and cardiovascular events

BackgroundAppropriate use criteria for myocardial perfusion imaging (MPI) were developed to categorize scenarios where MPI might be beneficial (appropriate) or not (inappropriate). Few investigations have evaluated the clinical utility of this categorization strategy, particularly with positron emission tomography (PET) MPI.Methods and ResultsWe conducted this retrospective cohort investigation in a Veterans Affairs (VA) medical center, on predominantly male subjects who underwent PET-MPI. We correlated appropriateness to test result and cardiovascular events. Of 521 subjects, 414 (79.5%) were appropriate, 54 (10.4%) were uncertain, and 53 (10.2%) were inappropriate. PET-MPI was abnormal more often when appropriate or uncertain (28% and 34.6%, respectively, vs 7.7% for inappropriate, Pxa0=xa0.003). Among abnormal inappropriate tests, none detected occult ischemia. By Cox regression, summed difference score ≥5 (HR 5.06, 95% CI 2.72-9.44) and an abnormal test result (HR 4.48, 95% CI 2.19-9.14) were associated with higher likelihood of catheterization. Log-rank analysis demonstrated similar likelihood of catheterization when comparing abnormal vs normal test result (Pxa0<xa0.0001) and between appropriate, uncertain, and inappropriate tests (Pxa0=xa0.024).ConclusionsInappropriate PET-MPI was rarely abnormal, associated with low catheterization rates, and failed to detect occult ischemia for any subjects. The clinical utility of inappropriate PET-MPI is negligible.

Use of Chest Wall Electromyography to Detect Respiratory Effort during Polysomnography

STUDY OBJECTIVESnTo evaluate the ability of chest wall EMG (CW-EMG) using surface electrodes to classify apneas as obstructive, mixed, or central compared to classification using dual channel uncalibrated respiratory inductance plethysmography (RIP).nnnMETHODSnCW-EMG was recorded from electrodes in the eighth intercostal space at the right mid-axillary line. Consecutive adult clinical sleep studies were retrospectively reviewed, and the first 60 studies with at least 10 obstructive and 10 mixed or central apneas and technically adequate tracings were selected. Four obstructive and six central or mixed apneas (as classified by previous clinical scoring) were randomly selected. A blinded experienced scorer classified the apneas on the basis of tracings showing either RIP channels or the CW-EMG channel. The agreement using the two classification methods was determined by kappa analysis and intraclass correlation.nnnRESULTSnThe percentage agreement was 89.5%, the kappa statistic was 0.83 (95% confidence interval 0.79 to 0.87), and the intraclass correlation was 0.83, showing good agreement. Of the 249 apneas classified as central by RIP, 26 were classified as obstructive (10.4%) and 7 as mixed (2.8%) by CW-EMG. Of the 229 events classified as central by CW-EMG, 7 (3.1%) were classified as obstructive and 6 (2.6%) as mixed by RIP.nnnCONCLUSIONSnMonitoring CW-EMG may provide a clinically useful method of detection of respiratory effort when used with RIP and can prevent false classification of apneas as central. RIP can rarely detect respiratory effort not easily discernible by CW-EMG and the combination of the two methods is more likely to avoid apnea misclassification.

Use of Chest Wall EMG to Classify Hypopneas as Obstructive or Central

STUDY OBJECTIVESnTo compare classification of hypopneas as obstructive or central based on an effort signal derived from surface chest wall electromyography (CW-EMG-EF) coupled with airflow amplitude versus classification using The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications (AASM Scoring Manual) criteria; and to characterize hypopneas classified as obstructive versus central using a resistance surrogate.nnnMETHODSnCW-EMG was recorded in the eighth intercostal space at the right midaxillary line. Five hypopneas were randomly selected from 65 consecutive adult clinical positive airway pressure titration studies meeting study criteria. A blinded scorer classified the hypopneas based on two groups of signals: Group 1: positive airway pressure flow (PAP flow), chest and abdominal effort, and snoring; or Group 2: smoothed PAP flow (for blinding amplitude but not flattening visible) and effort (CW-EMG-EF). A resistance surrogate (CW-EMG-EF / PAP flow) normalized to a pre-event breath was compared between obstructive and central hypopneas classified by AASM Scoring Manual criteria.nnnRESULTSnThe percentage agreement (Group 1 versus Group 2) was 92% and the kappa was 0.75 (95% confidence interval 0.65 to 0.85). The resistance surrogate was significantly higher in obstructive hypopneas versus central hypopneas during the first and second half of hypopneas. The resistance surrogate (mean ± standard deviation) for the second half of hypopnea was obstructive: 7.59 ± 7.24 versus central: 1.27 ± 0.56, P < .001). The resistance surrogate increased from the first to second half of hypopnea only for obstructive hypopneas.nnnCONCLUSIONSnCW-EMG provides a useful complementary signal for hypopnea classification and a resistance surrogate based on CW-EMG is much higher in hypopneas classified as obstructive by AASM Scoring Manual criteria.

A Patient With Suspicious Oxygen Desaturations at Sleep Onset

Journal of Clinical Sleep Medicine, Vol. 14, No. 8 August 15, 2018 Your sleep tech asks you to check on the veracity of oxygen desaturations noted prior to sleep onset in a child who presented for a sleep study to evaluate the family’s reports of apneic events. The patient is a 2-year-old female who was referred by a pediatric neurologist for further evaluation of the family’s reports of apnea noted prior to sleep onset. The child was developing normally until approximately 6 months prior when she began to have regression of language and developed unusual hand movements. Physical examination was most remarkable for mild decrease in head circumference with child noted to be SLEEP MEDICINE PEARLS

A Patient With Rapidly Progressing Early-Onset Dementia and Insomnia

Journal of Clinical Sleep Medicine, Vol. 13, No. 11, 2017 apparent on the original visit. She came with a family member who reported sudden onset and rapid worsening of the patient’s cognition with new issues of confusion and disorientation. Short-term memory was poor, but long-term memory remained intact. Mini-Mental Status Examination yielded 2 out of 3 correct for recall. Hyperhidrosis was more prominent occurring during wakefulness hours as well as during sleep. The patient’s sleep-wake schedule was erratic with intermittent brief dozing day and night. Her sleep behaviors, such as dressing herself, combing her hair, and tying her shoes, were more complex. Initially dream enactment behaviors were simpler with calling out and sitting up in bed. She was unresponsive during these periods, amnestic for her actions in sleep, but awoke oriented. Despite efforts to use PAP, the patient would disassemble her interface while asleep. She reported horizontal diplopia, new-action tremor, and a 12-lb weight loss. Her pertinent vital signs were blood pressure 164/108 and heart rate 110 bpm. Comprehensive metabolic panel, thyroid function tests, urinalysis, and head computed tomography were unrevealing. Repeat PSG was attempted on continuous positive airway pressure with the patient demonstrating little sleep (Table 1). A 51-year-old woman presented with insomnia for 2 months and daytime sleepiness for 6 months. The patient attributed the insomnia to stress from recent life events. Her Epworth Sleepiness Scale score was 18 of 24. Observers of the patient reported loud snoring, apneas, kicking, and dream enactment. The patient had hyperhidrosis during sleep. Family history was positive for hypertension and dementia. Social history excluded tobacco, alcohol, or illicit drug usage. Review of symptoms was significant for heart palpitations, headaches, and depression. The patient’s medical history was negative with no medications. Physical examination revealed a blood pressure of 140/90 and body mass index of 30.3 kg/m2. The patient’s Mallampati score was class IV. Physical examination was otherwise unremarkable. Neurological examination showed normal reflexes, gait, and intellect with good recent and remote memory recall. Diagnostic polysomnography (PSG) showed apnea-hypopnea index, 84.4 events/h; periodic limb movement index, 10.7 events/h; reduced total sleep time (140 minutes); increased stage N1 sleep; and no stage N3 or R sleep. Minimum oxygen saturation was 80%. Sleep spindles were absent. The patient refused an in-laboratory positive airway pressure (PAP) titration, and was placed on auto-adjusting PAP therapy for her severe obstructive sleep apnea. At follow-up, 8 weeks after starting auto-adjusting PAP therapy, the patient demonstrated cognitive impairment not SLEEP MEDICINE PEARLS