Noncontact Infant Apnea Detection for Hypoxia Prevention With a K-Band Biomedical Radar

Annually, a significant number of premature infants suffer from apnea, which can easily cause a drop in oxygen saturation levels, leading to hypoxia. However, infant cardiopulmonary monitoring using conventional methods often necessitates skin contact, and they are not suitable for long-term monitoring. This article introduces a non-contact technique for infant cardiopulmonary monitoring and an adjustable apnea detection algorithm. These are developed using a custom-designed K-band continuous-wave biomedical radar sensor system, which features a DC-coupled adaptive digital tuning function. By using radar technology to detect chest motions without physical contact, it is feasible to extract significant biological information regarding an infant's respiration and heartbeat. The proposed algorithm utilizes an adaptively adjusted threshold and personalized apnea warning time to automatically measure the total number of apneic events and their respective durations. Experiments have been conducted in clinical environment, demonstrating that both the accurate cardiopulmonary signals and the apneas of varying durations can be effectively monitored using this method, which suggest that the proposed technique has potential applications both inside and outside of clinical settings.

Harmonizing work with the treatment and prevention of sleep disordered breathing in commercial motor vehicle drivers: implications for health and productivity management

The desastrous traffic accidents to date have provided the relevance for promotion of harmonization of work with treatment and prevention of sleep disordered breathing (SDB) in transport sectors. SDB is highly prevalent in commercial motor vehicle (CMV) drivers and is one cause of cognitive impairment and consequent traffic accidents, potentially costing billions and leading to many deaths. Various screening, diagnostic, and therapeutic approaches, some well established, are explored in this paper. Although drivers with SDB need to be appropriately diagnosed and treated, some are reluctant to continue their treatment or never submit to screening because of a lack of information. Thus, CMV drivers need to be well informed and screened, in addition to being encouraged to continue the treatment. The harmonization of work with treatment and prevention aids these objectives, providing benefits not only for individual health but also for transport companies, and further being an essential step towards uptake of "health and productivity management" in the transport sectors.

Overcoming sleep disordered breathing and ensuring sufficient good sleep time for a healthy life expectancy

Recent advances in basic and clinical medicine have resulted in major improvements in human health. Currently sleep has been considered an essential factor in maintaining and promoting a healthy life expectancy. Sleep disorders include more than 60 diseases. Sleep disordered breathings (SDB) have 17 disorders, including sleep apnea. SDB usually induces hypoxemia and hypercapnia, which would have significant effects on cells, organs, and the whole body. We have investigated SDB for nearly 35 years. We found that SDB has significant associations with humoral factors, including coagulation systems, the body's protective factors against diseases, and metabolic and organ diseases. Currently we have been giving attention to the associations among SDB, short sleep duration, and obesity. In addition, SDB is important not only in the home but under critical care such as in the perioperative stage. In this review, I would like to describe several aspects of SDB in relation to systemic diseases and overall health based mainly on our published reports.

[Sleep-disordered breathing and cardiac resynchronization therapy]

Patients with progressive heart failure often suffer from sleep-disordered breathing (SDB). Upon receiving cardiac resynchronization therapy (CRT), there is an improvement of cardiac function and central sleep apnea syndrome (CSA) with Cheyne-Stokes respiration; however, effects of CRT on obstructive sleep apnea syndrome seemed to be without clinical relevance. Likewise, additional atrial overdrive pacing did not improve CRT effects relevantly in CSA patients. During CRT, there is an improvement in sleep parameters, sleep quality by reduction of depressive syndromes, and in long-term survival. Therefore, all patients with chronic heart failure and indication for CRT should be monitored regarding SDB before and after CRT device implantation.

[Sleep apnea syndrome or atrio-ventricular block and hypertension?]

A case of hypertensive patient with obstructive sleep apnea syndrome is presented. The third degree atrio-ventricular block was detected during diagnostic procedure and treatment of blood pressure in patient with obstructive sleep apnea. A heart pacemaker has been implanted. After this procedure the sleep apnea signs have not been detected.

Effects of cardiac resynchronization therapy on sleep apnea, quality of sleep and daytime sleepiness in patients with chronic heart failure

BACKGROUND

Sleep-related breathing disorders are common in patients with chronic heart failure (CHF) and contribute to exacerbation of CHF. The effects of biventricular stimulation (CRT) seem to exceed the improvement of mechanical heart performance and are likely to affect other aspects of CHF pathophysiology. The aim of the study was to assess the influence of CRT on subjective and objective sleep features.

MATERIAL AND METHODS

Twenty seven consecutive patients (aged 67.7 +/- 8.7 years, 23 men - 85%) with chronic heart failure (62.9% with ischaemic background and 37.1% of non-ischaemic etiology) in stable for at least 3 months NYHA class III - IV despite optimized pharmacotherapy, with left ventricular end-diastolic diameter (LVEDd) > 55 mm, left ventricular ejection fraction (LVEF) < or = 35% and wide QRS complex (> or = 120 ms) were appraised before and 12-16 weeks after CRT introduction clinically (including 6-minute walk test--6-MWT), echocardiographically and in polisomnography. The apnea-hypopnea index (AHI) and apnea indexes (AI) of central, obstructive and mixed types were calculated. The sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI), daytime sleepiness with the Epworth Sleepiness Scale (ESS).

RESULTS

LVEF increased, 6-MWT distance rose. Left ventricular diameters and left ventricular end-systolic volume decreased. PQSI and ESS fell (9.3 +/- 4.2 vs 6.2 +/- 3.2, p < 0.001 and 8.4 +/- 4.1 vs 7.0 +/- 3.4, p < 0.001, respectively). AHI, obstructive AL and mixed AL did not alter but significant reduction of central AL was noted (9.6 +/- 13.0 vs 3.7 +/- 6.2, p = 0.023).

CONCLUSIONS

CRT decreases central sleep apnea and improves quality of sleep and daytime sleepiness in patients with CHF.

Orthodontic treatment in children to prevent sleep-disordered breathing in adulthood

The purpose of this article is to review human craniofacial growth and development, especially the growth of the mandible, to clarify the relationship between obstructive sleep apnea (OSA) syndrome and craniofacial abnormality, and finally, to propose the hypothesis that negative pressure produced in the chest of the OSA child inhibits the growth of the mandible. Recently, the development of diagnosis and treatment of OSA syndrome has progressed rapidly; however, the prevention of OSA syndrome was merely seen. Craniofacial abnormality is reported as one of the causes of OSA syndrome. If craniofacial abnormality is determined only by genetics, it is difficult to manage the craniofacial skeleton to prevent OSA syndrome. The role of epigenetic factors on craniofacial growth and development is still controversial. However, if we stand on the functional matrix hypothesis, we can manage not only growth of the mandible but also the craniofacial skeleton as a whole. The author proposes the hypothesis that the negative pressure produced in the chest prohibits the growth of the mandible even if the patients have a capacity for growth and development; therefore, if this negative pressure disappears because of the removal of the tonsil and/or adenoids or by an orthodontic treatment to make a patency of the airway, the mandible may grow normally, and we can prevent or reduce a number of OSA syndromes in the future.

Sleep-disordered breathing in heart failure and the effect of cardiac resynchronization therapy

Respiratory disturbances during sleep are common in patients with heart failure (HF) and can trigger the occurrence of sleep apnoea or deteriorate pre-existing breathing disorder. This in turn may lead to worsening of the HF itself. Optimal treatment for HF has been found to reduce respiratory disturbances during sleep significantly, whereas cardiac resynchronization therapy (CRT), achieved by biventricular pacing, appears to cause a further reduction in episodes of central type apnoea, although it may also have an effect on episodes of obstructive type. The beneficial effect of CRT is due to the patients' haemodynamic improvement and in the HF amelioration, and not due to some other effect resulting from the electrical stimulation of the heart. However, this therapeutic intervention by itself is insufficient for the effective treatment of respiratory disturbances during sleep and should be considered as an adjunctive treatment in addition to other established therapies.

Car seat test for preterm infants: comparison with polysomnography

OBJECTIVES

To monitor preterm infants in a cot and a car seat and compare an observed car seat trial with polysomnography (PSG).

DESIGN

Non-randomised controlled trial.

SETTING

Regional neonatal unit.

PATIENTS

Preterm infants before discharge.

INTERVENTIONS

Nap PSG respiratory and sleep variables were measured including gastro-oesophageal pH. Nurse observations included respiratory distress, apnoea measured by apnoea alarm, oxygen saturation and heart rate. Infants were studied supine in a cot and then in a car seat. Nursing observations were compared with PSG during the car seat trial only. Criteria for failure of the PSG and observed tests were predefined.

MAIN OUTCOME MEASURES

Difference in respiratory instability between cot and car seat. Concurrence regarding failure of the car seat trial between nurse-observed data and PSG.

RESULTS

20 infants (median gestation 33 weeks (range 28-35 weeks; median postmenstrual age (PMA) at study 36.5 weeks (range 35-38 weeks)) were studied. There were sufficient car seat data on 18 infants for comparison. There were fewer central apnoeas and arousals in the cot than the car seat (p = 0.047 and p = 0.024, respectively). Airway obstruction was not more common in the car seat. Younger PMA at time of study predicted failure in both car seat (p = 0.022) and cot (p = 0.022). The nurse-observed test had low sensitivity for predicting PSG failure but more accurately predicted airway obstruction on PSG.

CONCLUSIONS

Immature infants exhibit respiratory instability in cots and car seats. A car seat test does not accurately detect all adverse events during sleep in the seat.

Positioner--a method for preventing sleep apnea

CONCLUSIONS

A 'Positioner' preventing sleeping on the back can effectively reduce obstructive sleep apnea (OSA), but not always snoring for patients with long-term OSA. By preference, the device should be used for younger snorers without OSA as a training tool to avoid sleeping on the back. Instructions and support by a nurse are necessary for compliance.

OBJECTIVES

Snoring is a progressive condition with a prevalence of 25-30% among the adult male population. Long-term snoring seems to be the basis for apneas caused by vibration damage to the pharyngeal tissue. Patients with OSA often have more apneas in the supine position than in the lateral position. Preventing sleeping on the back is a way to treat OSA. The aim of this study was to evaluate the efficacy and comfort of a recently developed Positioner.

SUBJECTS AND METHODS

A total of 23 patients diagnosed with positional sleep apnea (AHI>15 in supine position and AHI<5 in lateral position), were included. The Positioner--a soft vest, attached to a board placed under the pillow, makes it impossible for the patient to sleep on his back. It was fitted and tried out individually. Patients answered sleep questionnaires and kept sleep diaries before beginning use. After 3 months, a new sleep study was done while using the Positioner and new questionnaires were filled out.

RESULTS

Eighteen patients (5 women and 13 men) completed the study. The rest could not tolerate being strapped into the Positioner. Of those participating, 61% demonstrated a decrease of AHI to<10 using the Positioner. The Epworth Sleepiness Scale (ESS) decreased from a mean of 12.3 to 10.2. Half of the patients snored more frequently with the Positioner. The evaluation of comfort showed that minor adjustments are desirable.

Sleep apnea is induced by a high-fat diet and reversed and prevented by metformin in non-obese rats

OBJECTIVE

We assessed the relationship between a high-fat (HF) diet and central apnea during rapid eye movement and non-rapid eye movement sleep stages by recording ventilatory parameters in 28 non-obese rats in which insulin resistance had been induced by an HF diet. We also studied whether metformin (an anti-hyperglycemic drug frequently used to treat insulin resistance) could reverse sleep apnea or prevent its occurrence in this experimental paradigm.

RESEARCH METHODS AND PROCEDURES

Rats were fed with a standard diet (10 rats), an HF diet (8 rats), or an HF diet concomitantly with metformin treatment (10 rats). Each animal was instrumented for electroencephalographic and electromyographic recording. After 3 weeks, ventilatory parameters during sleep were recorded with a body plethysmograph. All rats were treated with metformin for 1 week, after which time the ventilatory measurements were measured again.

RESULTS

Our results showed that the three groups of animals did not differ in terms of body growth over the entire experimental period. The HF diet did not modify sleep structure or minute ventilation in the different sleep stages. A great increase (+266 +/- 48%) in central apnea frequency was observed in insulin-resistant rats. This was explained by an increase in both post-sigh (+195 +/- 35%) and spontaneous apnea (+437 +/- 65%) in the different sleep stages. These increases were suppressed by metformin treatment.

DISCUSSION

Insulin resistance induced by the HF diet could be the promoter of sleep apnea in non-obese rats. Metformin is an efficient curative and preventive treatment for sleep apnea, suggesting that insulin resistance modifies the ventilatory drive independently of obesity.

Lungenresektionen

The physician involved in internal medicine and general practice is confronted with a series of challenges in patients with pulmonary resection. In the early post-operative phase, optimal analgesia and physiotherapy are the primary factors for achieving the best possible function after loss of pulmonary tissue and for the determination of complications. Post thoracotomy syndrome requires interdisciplinary therapy. In the later course, it is necessary to take into consideration effects on pulmonary circulation, on the musculoskeletal system and on the digestive tract as well as sleep disturbances due to diaphragm dysfunction. Corresponding symptoms should be considered and actively sought, for example using echocardiography for assessment of cor pulmonale or outpatient sleep monitoring for detection of sleep-disordered breathing. Thus, aftercare includes much more than the search for a relapse or formation of metastases in cases of the most common cause of pulmonary resection, bronchial cancer.

Analysis of interaction of acute atrial overdrive pacing with sleep-related breathing disorder

Dose-related effects of atrial overdrive pacing (AOP) on sleep-related breathing disorder (SRBD) were studied. Fourteen patients with pacemakers with moderate to severe SRBD (mean screening apnea-hypopnea index [AHI] 35.2 +/- 21.9 events/hour) were randomized to 3 levels of pacing (50, 10, and 20 beats/min greater than the mean nocturnal heart rate) and studied by polysomnography, observing for changes in AHI. At the 2 AOP levels, no significant change was observed in the primary end point of reduction in AHI. Additionally, there was no observed impact on secondary end points of the study. Cyclic variation of heart rate was progressively abolished with higher levels of AOP without affecting AHI. Large variations were observed between the screening and control studies in SRBD indexes in a number of patients. In conclusion, AOP demonstrated no benefit to predominantly obstructive SRBD disorder of at least moderate severity.

Parent-rated behavior problems associated with overweight before and after controlling for sleep disordered breathing

Background

Researchers and clinicians are seeking to develop efficacious behavioral interventions to treat overweight children; however, few studies have documented the behavioral correlates of overweight children in community samples. The goal of this study was to determine the nature and prevalence of behavior problems for overweight school-aged children versus normal weight peers before and after controlling for the effect of sleep disordered breathing.

Methods

Hispanic and Caucasian children were invited to participate in a study of sleep through public elementary school classrooms. Anthropometric evaluation and behavioral ratings were collected for 402 children aged 6–11 years. Overweight was calculated using the Centers for Disease Control age- and gender-specific guidelines. Children were classified as overweight if they were at or above the 95th percentile for their age and gender group. Behavior problems were measured using the Conners' Parent Rating Scales-Revised and the Child Behavior Checklist. Sleep disordered breathing was assessed using in-home overnight polysomnography.

Results

Approximately 15% (59/402) of the sample was classified as overweight. Simple odds ratios indicated that overweight children were more likely to have clinically relevant levels of internalizing symptoms (OR 2.23, CI 1.05–4.72), psychosomatic complaints (OR 2.15, CI 1.02–4.54), withdrawal (OR 4.69, CI 2.05–10.73), and social problems (3.18, 1.53–6.60). When odds ratios were adjusted for level of sleep disordered breathing, withdrawal (OR 3.83 CI 1.59–9.22) and social problems (OR 2.49 CI 1.14–5.44) remained significantly higher for overweight subjects.

Conclusion

After controlling for the effect of sleep disordered breathing, behaviors such as withdrawal and social problems, are common in overweight children and need to be taken into account in the design of interventions and services as they may act to moderate the efficacy of behavioral treatments.

Dental management of patients with hypertension

About 50 million people in the United States have hypertension. Many epidemiologists feels it is the number one public health problem in developed countries. Although asymptomatic early on, untreated hypertension leads to cardiovascular disease, strokes, renal failure, and blindness. Dentists no doubt treat patients with hypertension and its sequelae in their practice. This article summarizes the current thinking on the diagnosis and treatment of this condition, emphasizing dental implications. The article presents common oral and systemic side effects of antihypertensive medications, and discusses how dentists can help treat hypertension through the fabrication of devices useful in reducing obstructive sleep apnea.

Rückenmarknahe Regionalanästhesieverfahren bei Kindern - Kaudalblock und Spinalanästhesie

Caudal anesthesia is a safe, simple and very effective method to provide excellent perioperative analgesia. It is used routineously in pediatric anesthesia and can be applied to nearly all children with surgery below the umbilicus. In contrast, spinal anesthesia is a very special technique for former preterm infants below the 50th postconceptive week who are prone to develop postoperative apnea. It has been suggested that some of the problems associated with general anesthesia in these patients may be avoided by the use of spinal anesthesia.

Snoring and sleep apnoea: how it can be prevented in childhood

Obstructive sleep apnoea (OSA) is a very serious health problem in our society today. Medical consequences are significant, health-care costs high and good treatment options limited. The best treatment is prevention. This article addresses the issue.

Effects of exercise on sleep

Historically, perhaps no daytime behavior has been more closely associated with better sleep than exercise. The assumption that exercise promotes sleep has also been central to various hypotheses about the functions of sleep. Hypotheses that sleep serves an energy conservation function, a body tissue restitution function, or a temperature down-regulation function all have predicted a uniquely potent effect of exercise on sleep because no other stimulus elicits greater depletion of energy stores, tissue breakdown, or elevation of body temperature, respectively. Exercise offers a potentially attractive alternative or adjuvant treatment for insomnia. Sleeping pills have a number of adverse side effects and are not recommended for long-term use, partly on the basis of a significant epidemiologic association of chronic hypnotic use with mortality. Other behavioral/cognitive treatments are more effective for chronic insomnia treatment, but difficult and costly to deliver. By contrast, exercise could be a healthy, safe, inexpensive, and simple means of improving sleep.

Obesity, Sleep Apnea Syndrome, and Rhythmogenic Risk

Obstructive sleep apnea is a common disorder and affects approximately 4% of middle-aged men and 2% of middle-aged women. Obstructive sleep apnea is clearly associated with obesity, with more than 50% of patients having a body mass index>30 kg/m2. Substantial evidence identified obstructive sleep apnea as risk factor not only for excessive daytime sleepiness and road traffic accidents, but also for increased cardiovascular morbidity and mortality. In addition, all kinds of arrhythmias have been observed in patients with sleep apnea ranging from asymptomatic sinus bradycardia to sudden cardiac death. Approximately 5-10% of patients with obstructive sleep apnea show marked apnea-related bradyarrhythmias due to enhanced vagal tone and pronounced hypoxia. Therapeutic options in obese patients with obstructive sleep apnea include consequent weight loss and nasal continuous positive airway pressure (CPAP) ventilation as the therapy of first choice. Weight reduction and effective nasal CPAP therapy significantly decrease cardiovascular morbidity and mortality and eliminate sleep-related bradyarrhythmias in 80-90% of patients obviating the need for pacemaker implantation in these patients.

Medical treatment of acromegaly: comorbidities and their reversibility by somatostatin analogs

Relief of symptoms can be achieved following surgery for growth hormone (GH)-secreting adenomas, as well as after pharmacological therapy with somatostatin analogs. Recently, long-acting somatostatin analog depot formulations, octreotide LAR and lanreotide SR have become available. Somatostatin analogs control GH/insulin-like growth factor (IGF)-1 excess, induce tumor shrinkage in a high proportion of patients, improve symptoms of acromegaly with relatively limited side effects and are successfully administered in patients not suitable for surgery. Furthermore, preoperative somatostatin analogs have been suggested to improve outcome for tumors with limited invasiveness, while surgical tumor debulking in cases that are, at least partially, somatostatin resistant, increases the achievement of normal IGF-1 levels by postoperative somatostatin analog treatment. Effective control of hypertension, as well as diabetes, is mandatory in order to reduce the increased vascular morbidity/mortality. Control of GH/IGF-1 excess generally improves glucose metabolism. Somatostatin analogs improve insulin sensitivity, exerting, however, a concomitant direct inhibitory effect on insulin secretion, with a net balance leaning towards a deterioration in glucose homeostasis. As a result, oral insulin secretagogues (and/or insulin) should probably be preferred to insulin sensitizers in acromegalic patients developing diabetes while on somatostatin analogs. Nevertheless, glucose tolerance remains normal in most of the nondiabetic acromegalic patients, while diabetic acromegalic patients on insulin are at risk for hypoglycemia during initiation of somatostatin analog therapy. Although successful management of acromegaly has been associated with improvement in morphological and functional parameters of cardiomyopathy, limited and conflicting information is available regarding the effect on blood pressure control. Contradictory results have also been reported regarding sleep hypopnea or apnea in treated acromegalic patients. As acromegalic skeletal abnormalities are rather irreversible, apneic episodes may persist after normalization of hormonal levels. Aggressive therapy, including surgery, pharmacological treatment and, in some cases, pituitary irradiation, aiming at normalization of IGF-1 levels, is required for arthropathy management. Some improvement in pain, crepitus and range of motion has been observed after treatment with somatostatin analogs. Information on the impact of disease control, either by surgery or somatostatin analog treatment, on gonadal function is limited. Finally, the link between the hormonal/biochemical and the psychiatric/psychological features of acromegaly, as well as a potential basis for positive effects of somatostatin analog therapy remain unclear.

Percutaneous Computed Tomography-Guided Transdiscal Low Cervical Cordotomy for Cancer Pain as a Method to Avoid Sleep Apnea

OBJECTIVE

Study of percutaneous computed tomography (CT)-guided transdiscal low cervical cordotomy undertaken to treat pain in cancer patients.

METHODS

At the Department of Neurosurgery, Ain Shams University, Cairo, Egypt, 8 cancer pain patients, with either impaired pulmonary function or a previous cordotomy on an opposite side (sleep apnea was a feared complication) that prevented the possibility of undergoing a C(1-2) cordotomy, underwent a percutaneous CT-guided transdiscal low cervical cordotomy (C(4-5) or C(5-6)) to treat cancer pain.

RESULTS

Seven patients experienced initial improvement. One patient re-experienced pain within 2 weeks and 1 patient experienced no pain relief. In 6 patients in whom the cordotomy procedure was completed, satisfactory or complete pain relief, throughout a 6-month follow-up period was reported. In contrast, in 2 patients in whom the cordotomy was not completed there was no persistent pain relief.

CONCLUSION

Percutaneous CT-guided cordotomy remains a successful procedure to control pain in cancer patients, and is an affordable viable option under circumstances where economic disadvantage is an overriding determinate.

Thyroxine replacement therapy reverses sleep-disordered breathing in patients with primary hypothyroidism

BACKGROUND AND PURPOSE

Anecdotal reports suggest that sleep-disordered breathing (SDB) is common among patients with primary hypothyroidism. This study was undertaken to determine the prevalence of SDB and to evaluate the effect of thyroxine replacement therapy on SDB in patients with primary hypothyroidism.

PATIENTS AND METHODS

Fifty consecutive newly diagnosed, untreated symptomatic patients with primary hypothyroidism (age: 34+/-11 years; males: 21 [42%]) were prospectively studied. Physical examination, anthropometry, fasting blood glucose and serum lipids were performed in all patients at baseline. Polysomnography was done at baseline in all patients and was repeated after adequate thyroxine replacement in those who had SDB.

RESULTS

SDB defined as apnea-hypopnea index (AHI) > or =5 was present in 15 patients (30%) at baseline and was reversible in 10 of the 12 patients evaluated following thyroxine replacement therapy (P=0.006). Thyroxine replacement therapy was associated with improvement in findings that reflect a compromised upper airway, such as macroglossia (4 [33%] vs. 1 [8%]; P=0.083), myoedema (5 [42%] vs. 1 [8%]; P=0.046) and facial puffiness (10 [83%] vs. 1 [8%]; P=0.003).

CONCLUSIONS

Reversible SDB is common among patients with primary hypothyroidism. Changes in upper airway anatomy resulting from hypothyroidism probably contribute to the development of SDB in these patients.