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N A Collop

Publications and source records attributed to N A Collop.

At least 19 recordsLinked to original sources
PubMed2001

The association of upper airway resistance with periodic limb movements.

STUDY OBJECTIVES: We hypothesized that the upper airway resistance syndrome (UARS), the component event being a respiratory effort related arousal (RERA), and periodic limb movements in sleep (PLMS), the component event being repetitive, stereotyped extremity movements occurring in a periodic fashion, were associated in certain patients. DESIGN: Invasive polysomnography using Pes and full facemask pneumotachography was used to identify RERA's in patients. Periodic limb movements (PLM) were scored according to standard criteria and as associated with RERA if the movement occurred between the Pes nadir and the onset of the arousal. SETTING: A university hospital Sleep Disorders Laboratory. PARTICIPANTS: Patients consecutively diagnosed with PLMS in our sleep disorders laboratory over a 1 year period. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Fourteen of twenty patients demonstrated UARS in addition to PLMS (70%). In those 14, 63% of RERAs were associated with a PLM (mean = 51.7 + 36.2 PLM/RERAs per study vs 5.6 + 6.3 PLM/RERAs per study if the association were random). Patients with UARS had more arousals with their PLMs (P = 0.0006). CONCLUSIONS: An association exists between PLMS and UARS on both a group level and an event level. A high percentage of PLM with arousals correlated with breathing events due to increased effort in UARS; this may be of clinical utility in the management of PLMS patients.

Adult↗
PubMed2001

Lysis of a left ventricular thrombus with recombinant tissue plasminogen activator.

A 23-year-old woman with peripartum cardiomyopathy presented with a 2.1 x 2.5-cm pedunculated, mobile, left ventricular thrombus and evidence of systemic embolization. Due to the patient's poor left ventricular function, thrombectomy was not a viable option. Treatment with high-dose IV heparin was initially utilized but was unsuccessful as the thrombus appeared to enlarge on echocardiography. An accelerated weight-adjusted dose of recombinant tissue plasminogen activator (rt-PA) successfully lysed the thrombus without evidence of embolization. Although rt-PA has been used for primary lysis of high-risk ventricular thrombi, this is the first documentation of successful lysis of a left ventricular thrombus in a patient with peripartum cardiomyopathy.

Adult↗
PubMed1999

Indications for positive airway pressure treatment of adult obstructive sleep apnea patients: a consensus statement.

We developed a short-length document that clearly delineates a prudent approach to and criteria for reimbursement of positive airway pressure (PAP) costs for the treatment of obstructive sleep apnea (OSA). Treatment modalities for OSA with PAP include continuous positive airway pressure, bilevel or variable PAP, and autotitrating PAP. This guidance on the appropriate criteria for PAP use in OSA is based on widely acknowledged peer-reviewed studies and widely accepted clinical practice. These criteria reflect current opinion on the appropriate clinical management of OSA in lieu of data pending from the Sleep Heart Health Study and upcoming outcome studies. This document is not intended to provide a complete review and analysis of the OSA clinical literature. The key to the success of this document is to foster consensus within and outside the clinical sleep community by providing a common sense and easily understood approach to the treatment of OSA with PAP.

Adult↗
PubMed1999

The upper airway resistance syndrome.

The upper airway resistance syndrome (UARS) is a recently described form of sleep-disordered breathing in which repetitive increases in resistance to airflow within the upper airway lead to brief arousals and daytime somnolence. This review will first describe the chronological progression of our understanding of UARS within the broader context of sleep-disordered breathing. The primary symptom, daytime somnolence, appears to result directly from repetitive EEG arousals. The level of negative intrathoracic pressure is the most likely stimulus for arousal, possibly mediated by mechanoreceptors in the upper airway. A general consensus regarding the exact clinical definitions and the physiologic measurement techniques leading to a diagnosis does not exist, although esophageal manometry and pneumotachographic airflow measurements taken during polysomnography are the "gold standard." Less invasive diagnostic modalities have been proposed, but none of them have been well-validated. Aside from daytime somnolence, hypertension is an important sequela of this disorder, likely resulting from autonomic and cardiovascular changes induced by increased negative intrathoracic pressure. Nasal continuous positive airway pressure is the most efficacious form of therapy, although low patient compliance may limit its practical application. The safety and efficacy of surgical treatments are poorly documented in the literature. Palatal tissue reduction by radiofrequency ablation and the use of oral appliances hold promise as safe and effective modalities, but these treatments require further study.

Airway Resistance↗
PubMed1998

The effects of a high-protein, low-fat, ketogenic diet on adolescents with morbid obesity: body composition, blood chemistries, and sleep abnormalities.

OBJECTIVE: To evaluate the efficacy and metabolic impact of a high-protein, low-carbohydrate, low-fat ketogenic diet (K diet) in the treatment of morbidly obese adolescents with initial weights of >200% of ideal body weight. METHODS: Six adolescents, aged 12 to 15 years, weighing an average of 147.8 kg (range, 120.6-198.6 kg) and having an average body mass index of 50.9 kg/m (39.8-63.0 kg/m), consumed the K diet for 8 weeks. Daily intake consisted of 650 to 725 calories, which was substantively in the form of protein (80-100 g). The diet was very low in carbohydrates (25 g) and fat (25 g). This was followed by 12 weeks of the K diet plus two carbohydrates (30 g) per meal (K+2 diet). MAIN OUTCOME MEASURES: Anthropometric data and blood and urine were collected at enrollment, during week 1, and at 4-week intervals throughout the course of the study. Resting energy expenditure was measured by indirect calorimetry. Body composition was estimated using dual-energy x-ray absorptiometry, bioelectrical impedance analysis, and urinary creatinine excretion at enrollment and on completion of each phase of the diet. Nocturnal polysomnography and multiple sleep latency testing were conducted at baseline and repeated after an average weight loss of 18.7 kg to determine sleep architecture, frequency and duration of apneas, and daytime sleepiness. RESULTS: Subjects lost 15.4 +/- 1.4 kg (mean +/- SEM) during the K diet and an additional 2.3 +/- 2.9 kg during the K+2 diet. Body mass index decreased 5.6 +/- 0.6 kg/m(2) during the K diet and an additional 1.1 +/- 1.1 kg/m(2) during the K+2 diet. Body composition studies indicated that weight was lost equally from all areas of the body and was predominantly fat. Dual-energy x-ray absorptiometry showed a decrease from 51.1% +/- 2.1% body fat to 44.2% +/- 2.9% during the K diet and then to 41.6% +/- 4.5% during the K+2 diet. Lean body mass was not significantly affected. Weight loss was accompanied by a reduction in resting energy expenditure of 5.2 +/- 1.8 kcal/kg of fat-free mass per day. Blood chemistries remained normal throughout the study and included a decrease in serum cholesterol from 162 +/- 12 to 121 +/- 8 mg/dL in the initial 4 weeks of the K diet. An increase in calcium excretion was accompanied by a decrease in total-body bone mineral content. A paucity of rapid eye movement sleep and excessive slow-wave sleep were seen in all subjects at enrollment. Weight loss led to an increase in rapid eye movement sleep (P < .02) and a decrease in slow-wave sleep (P < .01) to near normal levels. CONCLUSIONS: The K diet can be used effectively for rapid weight loss in adolescents with morbid obesity. Loss in lean body mass is blunted, blood chemistries remain normal, and sleep abnormalities significantly decrease with weight loss.

Adolescent↗
PubMed1997

Analysis of tube thoracostomy performed by pulmonologists at a teaching hospital.

STUDY OBJECTIVE: To evaluate all tube thoracostomies (TTs) done by pulmonary/critical care fellows and attending physicians in the Medical University of South Carolina's health-care system documenting patient demographics, indication for placement, size and characteristics of the tube, and associated problems. DESIGN: Prospective. SETTING: University health-care system, including a university hospital, a Veterans Affairs hospital, and a county hospital. PATIENTS: All adult patients requiring consultation by a member of the pulmonary/critical care staff for a tube thoracostomy. RESULTS: One hundred twenty-six tube thoracostomies were performed over a 24-month period in 91 patients. The most common initial indication for a TT was pneumothorax (69/103, 67%). Overall mortality in the patient population was 35% (32/91). Early problems (< 24 hours following placement) occurred in 3% (4/126); late problems (> 24 h after placement) occurred in 8% (10/126). Problems occurred in 36% (4/11) of small-bore tube placements vs 9% (10/115) of standard TT placements (p=0.02). CONCLUSIONS: Tube thoracostomy can be safely performed by pulmonologists with relatively few associated problems.

Adolescent↗
PubMed1995

Neurocognitive deficits in morbidly obese children with obstructive sleep apnea.

Neurocognitive abilities were measured in 14 morbidly obese children, five of whom had obstructive sleep apnea as determined by polysomnography. As in adults, children with obstructive sleep apnea had deficits in learning, memory, and vocabulary. Moreover, apneic/hypopneic events were inversely related to memory and learning performance among the entire sample.

Adolescent↗
PubMed1995

"Doctor mom".

Explore the source record for details and available documents.

Conflict, Psychological↗
PubMed1995

Accidental ingestion of a tracheal stent.

A 53-year-old man with tracheobronchomalacia had two stents placed in his airways to maintain patency. He ingested one of the tracheal stents that was inadvertently dislodged during a brief coughing episode. The swallowed stent was recovered without complications.

Bronchial Diseases↗
PubMed1994

Medroxyprogesterone acetate and ethanol-induced exacerbation of obstructive sleep apnea.

OBJECTIVE: To determine if medroxyprogesterone acetate (MPA) can block the ethanol-induced worsening of obstructive sleep apnea. DESIGN: Randomized, double-blind, placebo-controlled, crossover trial with 1 week treatment periods. SETTING: A university-based pulmonary sleep laboratory. PATIENTS: Fourteen patients with previously diagnosed obstructive sleep apnea not currently receiving any form of therapy for the disorder. Eight patients completed the entire protocol. INTERVENTIONS: Baseline overnight polysomnography was performed. On the second study night, subjects ingested 1 ml/kg body weight 50 percent ethanol prior to repeat overnight polysomnography. If sleep apnea worsened, subjects then received either MPA (20 mg by mouth, three times a day) or placebo for 7 days then underwent repeat polysomnography with the same ethanol dose. A washout period followed, then, the other drug was taken, followed again by polysomnography with antecedent ethanol ingestion. MEASUREMENTS AND RESULTS: Apnea-hypopnea indices (AHI) increased from 9.6 +/- 5.3 events/h (baseline) to 20.2 +/- 16.0 events/h on the ethanol night (p = 0.03). Low oxygen saturation (SaO2) fell to 79.2 +/- 5.1 percent on the ethanol night compared to baseline, 85.0 +/- 3.7 percent (p < 0.01). MPA improved AHI, nonrapid eye movement AHI, low SaO2, mean saturation nadir, number of desaturations between 80 and 90 percent, and the mean event desaturation when compared with the ethanol alone night. All these parameters were likewise improved when compared with placebo, although only the mean saturation nadir showed statistical significance. These findings were unchanged when also examined for the initial 3 hours of study. CONCLUSIONS: In obstructive sleep apnea patients whose disease is made worse by ethanol ingestion, MPA appears to improve oxygenation during obstructive events but not to improve their number or length.

Adult↗
PubMed1993

Failure of the circulatory system limits exercise performance in patients with systemic sclerosis.

OBJECTIVE: To determine the mechanisms for exercise impairment in symptomatic patients with systemic sclerosis (SSc) using breath-by-breath expired-gas analysis with incremental exercise testing. DESIGN: Prospective, open trial. PATIENTS AND METHODS: Fifteen consecutive patients with SSc seen at the Medical University Hospital (a tertiary referral center) with complaints of exercise intolerance underwent pulmonary function testing (spirometry, helium dilution lung volumes, and diffusing capacity of carbon monoxide) and incremental exercise testing on a cycle ergometer measuring oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory exchange ratio (R), oxygen saturation, blood pressure, and heart rate (HR). Values for oxygen uptake at anaerobic threshold (VO2AT) were derived graphically by blinded clinicians experienced in exercise testing, and the results were averaged. Ventilatory reserve and oxygen pulse were calculated from measured values, and all data were subjected to analysis by standard clinical algorithms. MEASUREMENTS AND MAIN RESULTS: Of 15 patients studied, 14 had either restrictive lung disease or normal results of spirometry on pulmonary function testing. One patient with a history of tobacco use had evidence of airways obstruction. Three patients were unable to exercise maximally (as determined by maximum respiratory exchange ratio [Rmax] greater than 1.09 or maximum heart rate [HRmax] greater than 85% predicted), and exercise testing was terminated in one with Mobitz type II atrioventricular block. The following data (mean +/- SEM) were obtained from 11 maximally exercising patients: VO2max 795 +/- 75 mL oxygen (O2)/min, R 1.34 +/- 0.05, VO2AT/VO2max predicted 0.21 +/- 0.02, O2 pulse 5.1 +/- 0.4 mL O2/beat, ventilatory reserve 0.52 +/- 0.06, and tidal volume/forced vital capacity ratio 0.46 +/- 0.02. Of the 11 patients completing breath-by-breath expired-gas analysis, all had circulatory impairment to exercise, as determined by low O2 pulse and low VO2 at anaerobic threshold, and circulatory impairment was limiting in 9 of 11 patients. Of those nine patients, four had evidence of impaired gas exchange compatible with pulmonary vascular disease. Arterial oxygen desaturation occurred in 2 of 11 patients. CONCLUSION: Circulatory impairment to exercise is common in SSc patients with exercise intolerance. Restrictive lung disease, although also common, does not limit exercise tolerance in patients capable of maximal effort.

Adult↗