Restless legs syndrome and pregnancy: prevalence, possible pathophysiological mechanisms and treatment.

Restless legs syndrome (RLS) is a common sleep disorder that may be associated with pregnancy. Studies have found that the prevalence of RLS among pregnant women ranged from 10 to 34%. Typically, there is complete remission of symptoms soon after parturition; however, in some patients, they may continue postpartum. RLS has been shown to be associated with a number of complications in pregnancy including preeclampsia and increased incidence of Cesarean sections. Although multiple hypotheses have been proposed to explain this association, each individual hypothesis cannot completely explain the whole pathogenesis. Present understanding suggests that a strong family history, low serum iron and ferritin level, and high estrogen level during pregnancy might play important roles. Vitamin D deficiency and calcium metabolism may also play a role. Medical treatment of RLS during pregnancy is difficult and challenging considering the risks to mother and fetus. However, in some cases, the disease may be severe enough to require treatment.

Complications of non-invasive ventilation techniques: a comprehensive qualitative review of randomized trials.

Non-invasive ventilation (NIV) has become a common treatment for acute and chronic respiratory failure. In comparison with conventional invasive mechanical ventilation, NIV has the advantages of reducing patient discomfort, procedural complications, and mortality. However, NIV is associated with frequent uncomfortable or even life-threatening adverse effects, and patients should be thoroughly screened beforehand to reduce potential severe complications. We performed a detailed review of the relevant medical literature for NIV complications. All major NIV complications are potentially life-threatening and can occur in any patient, but are strongly correlated with the degree of pulmonary and cardiovascular involvement. Minor complications can be related to specific structural features of NIV interfaces or to variable airflow patterns. This extensive review of the literature shows that careful selection of patients and interfaces, proper setting of ventilator modalities, and close monitoring of patients from the start can greatly reduce NIV complications.

Event-related evoked potentials in chronic respiratory encephalopathy.

BACKGROUND: Cognitive event-related potential (P(300)) is an index of cognitive processing time. It was found to be prolonged in dementia, renal, and hepatic encephalopathies, but was not extensively assessed in respiratory failure. OBJECTIVE: To evaluate P(300) changes in patients with respiratory failure, and especially those with mild or subclinical hypoxic-hypercapnic encephalopathy. METHODS: Auditory event-related evoked potential P(300) latency was measured using an oddball paradigm in patients with respiratory failure due to any cause (partial pressure of oxygen in arterial blood (PO(2)) should be 75 mm/Hg or less). Apart from blood gases measurement, patients underwent the Mini-Mental State Examination (MMSE). Patient performances were compared with that of matched normal control. Patients were admitted into the study from outpatient clinics and wards at King Khalid University Hospital and Sahara Hospital. RESULTS: Thirty-four patients (12 women, 22 men) were admitted to the study. Ages ranged from 19-67 years with a mean of 46.1 years. Respiratory failure was severe or very severe in 11 patients (33%), and mild or moderate in the rest (66%). Mean value for PO(2) and partial pressure of carbon dioxide in arterial blood (PCO(2)) were 63.7 and 45.2 mm/Hg, respectively. pH mean was 7.4 and O(2) saturation was 90.7%. P(300) latency ranged from 218 to 393 milliseconds, with a mean of 338.4 milliseconds. In comparison with control (309.9 milliseconds), there was a significant difference (P = 0.007). P(300) amplitude differences were not significant. No significant difference in MMSE was noted between mild and severe respiratory failure. Results of detailed neuropsychological assessment were clearly abnormal but were limited by the small number of tested patients. P(300) latency changes correlated significantly with age as well as severity of respiratory failure. P(300) was also significantly delayed whether hypoxia occurred with or without hypercapnia. CONCLUSION: Results show a significant delay of P(300) latency in patients with severe and mild respiratory failure. This was associated with subclinical encephalopathy in most patients, evidenced by a near-normal MMSE score. Apart from confirming the importance of P(300) latency measurement as a marker of respiratory encephalopathy, this study asserts the causal relationship between hypoxemia and cognitive derangement. Furthermore, it promotes the early use of oxygen therapy in a selected group of patients with mild or moderate respiratory failure, who have responsibilities which involve taking rapid critical decisions.

Periodic leg movements in narcolepsy patients: impact on sleep architecture.

INTRODUCTION: We assessed the effect of periodic leg movements (PLMs) on sleep architecture in narcolepsy patients by comparing sleep patterns in narcoleptics of comparable age with and without PLMs. METHODS: Patients diagnosed with narcolepsy between January 1999 and December 2005 were divided into those with PLM index >or= 5/hr and <5/hr. Each patient underwent polysomnographic recording followed by a multiple sleep latency test (MSLT). RESULTS: There were 47 patients, of mean age 28.9 +/- 1.8 years, 31 (66%) with PLM index >or= 5/hr and 16 (34%) with PLM index <5/hr. Arousal index, PLM arousals and total number of arousals were all significantly higher in narcoleptics with PLM index >or= 5/hr than in those with PLM index <5/hr. Significant correlations were found between PLM index and arousal index, stage shifts, Stage 1 and average sleep latency on MSLT. CONCLUSIONS: Our findings demonstrated that narcolepsy patients with PLMs have a higher arousal index and increased PLM arousals compared with narcolepsy patients without PLMs. The contribution of the above to the perceived sleep quality and daytime sleepiness is not clear.

Sleep duration and its correlates in a sample of Saudi elementary school children.

INTRODUCTION: This study was conducted to estimate sleep duration in Saudi elementary school children, sleep habits and practices that may affect it, and compare our results to published data in other societies. METHODS: Parents of elementary school children were surveyed regarding their children's bedtime, rise time, sleep duration at night and daytime nap duration during weekdays and weekends. A questionnaire inquiring about demographical data, specific sleep problems and habits, and home environment was completed by the parents. RESULTS: The study comprised 511 (50.5 percent) boys and 501 (49.5 percent) girls. During weekdays, bedtime for the whole group was 21.3 +/- 1.8 hours, rise time was 5.9 +/- 0.5 hours, total sleep time (TST) was 8.4 +/- 1.1 hours, and TST and nap was 9.98 +/- 1.3 hours. Multivariate analysis revealed that TST was affected by regularity of bedtime, mother's level of education, daytime naps, and the habits of watching television (TV) and playing computer games after 20.00 hours. CONCLUSION: Nighttime sleep duration is shorter in Saudi school children compared to published data. Several factors appeared to affect sleep duration, including mother's educational level, daytime naps and watching TV at night.

Does Ramadan fasting affect sleep?

Experimental fasting has been shown to alter the sleep-wakefulness pattern in various species. As fasting during Ramadan is distinct from experimental fasting, the physiological and behavioural changes occurring during Ramadan fasting may differ from those occurring during experimental fasting. There has been increased interest in recent years in sleep changes and daytime sleepiness during Ramadan. Moreover, many of those who fast during Ramadan associate this fasting with increased daytime sleepiness and decreased performance. This raises the question of whether Ramadan fasting affects sleep. In this review, we discuss the findings of research conducted to assess changes in sleep pattern, chronobiology, circadian rhythms, daytime sleepiness and function and sleep architecture during the month of Ramadan. Where applicable, these findings are compared with those obtained during experimental fasting.

Behaviour and time-course of sleep disordered breathing in patients with acute coronary syndromes.

To our knowledge, no study has examined the persistence of sleep disordered breathing in acute coronary syndrome (ACS) patients. We examined the time course of SDB in ACS patients by assessing them within days of the acute event and again after 6 months. Consecutive patients with ACS were asked to voluntarily participate in the study. Patients underwent an overnight polysomnography (PSG) approximately 3 days after the acute event. Patients with an apnea hypopnea index (AHI) > 10/h then underwent another PSG after they were stable (approximately 6 months). Fifty patients were studied. First PSG showed an AHI was 23.1 +/- 3.6/h. A second PSG was performed 6.1 +/- 0.3 months later on 21 patients and showed an AHI > 10/h in the first assessment. The AHI and the obstructive apnea index did not change over the 6 months. However, the central apnea index all was lower at the second assessment.

Knowledge and attitude of Primary Health Care Physicians towards sleep disorders.

OBJECTIVE: Although sleep disorders are common, these are under-recognized and underestimated by many workers in the medical field due to lack of physician`s education in sleep and sleep disorders. We conducted this survey to assess the general knowledge and attitude of Primary Health Care Physicians in Riyadh, Saudi Arabia towards sleep disorders. METHODS: A self-administered questionnaire was distributed to all Primary Health Care physicians working in Primary Health Care centers of the Ministry of Health in Riyadh. The following factors were assessed: demographic data of the participating physicians, their background about sleep disorders and their recognition of possible presentations, consequences and diagnostic tests for sleep disorders. RESULTS: Complete data was available from 209 physicians. Fifty three percent were males and 47% were females. Only 57% agreed that sleep disorders are a distinct medical specialty and 40% felt that sleep disorders are common medical problems based on their practice. The recognition of some of the serious consequences of Obstructive Sleep Apnea Syndrome was poor; motor vehicle accidents (63%), ischemic heart disease (40%), hypertension (50%) and pulmonary hypertension (13%). Only 15% had attended lectures about sleep disorders during their postgraduate training or practice. Physicians who have attended lectures about sleep disorders referred significantly more patients than physicians who have not attended any (P=0.003). CONCLUSION: We conclude that Primary Health Care physicians in Riyadh do not completely recognize the importance and impact of Obstructive Sleep Apnea Syndrome and other sleep disorders. Education of Primary Health Care physicians about sleep disorders may increase detection of sleep disorders; and hence, the number of referrals, the provision of proper treatment and the prevention of complications.

Clinical profile of sleep apnea syndrome. A study at a university hospital.

OBJECTIVES: To review a series of patients with sleep apnea syndrome, to promote more awareness and alert local health professionals to early diagnosis and treatment. METHODS: We studied, prospectively, 48 consecutive patients who were managed at the university hospital from 1992 to 1996. RESULTS: The male:female ratio was 1.4:1. The mean interval between onset of symptoms and the diagnosis was 5.5 years (range 0.25 to 30). In over half of the patients the diagnosis was not suspected upon referral. The mean body mass index was 42.8 kg/m2, (range 25 to 76). Daytime hypoxemia was present in 28 patients (58%), while 26 (54%) had Pa CO2 > 45 mmHg, mainly as a result of obesity-hypoventilation syndrome. Significant proportions had systemic and pulmonary hypertension (60% and 23%), and 32% had ischemic heart disease. All patients, but one, tolerated continuous positive airway pressure, but cost of the equipment led some to prefer surgical treatment that is offered free. CONCLUSION: This series shows a bias towards female sex and frequent association with obesity-hypoventilation syndrome. In many cases the diagnosis was not suspected suggesting poor recognition and awareness of sleep apnea syndrome. Monitoring pulse oximetry during sleep was helpful in the diagnosis and titration of continuous positive airway pressure. Ways of providing continuous positive airway pressure under the health system need to be studied.

Knowledge and attitude of primary health care physicians towards sleep disorders.

OBJECTIVES: Although sleep disorders are common, these are under-recognized and underestimated by many workers in the medical field due to lack of physician's education in sleep and sleep disorders. We conducted this survey to assess the general knowledge and attitude of Primary Health Care Physicians in Riyadh, Saudi Arabia towards sleep disorders. METHODS: A self-administered questionnaire was distributed to all Primary Health Care physicians working in Primary Health Care centers of the Ministry of Health in Riyadh. The following factors were assessed: demographic data of the participating physicians, their background about sleep disorders and their recognition of possible presentations, consequences and diagnostic tests for sleep disorders. RESULTS: Complete data was available from 209 physicians. Fifty three percent were males and 47% were females. Only 57% agreed that sleep disorders are a distinct medical specialty and 40% felt that sleep disorders are common medical problems based on their practice. The recognition of some of the serious consequences of Obstructive Sleep Apnea Syndrome was poor; motor vehicle accidents (63%), ischemic heart disease (40%), hypertension (50%) and pulmonary hypertension (13%). Only 15% had attended lectures about sleep disorders during their postgraduate training or practice. Physicians who have attended lectures about sleep disorders referred significantly more patients than physicians who have not attended any (P=0.003). CONCLUSION: We conclude that Primary Health Care physicians in Riyadh do not completely recognize the importance and impact of Obstructive Sleep Apnea Syndrome and other sleep disorders. Education of Primary Health Care physicians about sleep disorders may increase detection of sleep disorders; and hence, the number of referrals, the provision of proper treatment and the prevention of complications.

Health care utilization in males with obstructive sleep apnea syndrome two years after diagnosis and treatment.

OBJECTIVE: To document changes in health care utilization (physician claims and hospitalizations) two years after diagnosis and treatment of patients with OSAS. DESIGN: Prospective observational cohort study. SETTING: The study was done in the Canadian Province of Manitoba. OSAS patients were selected from a University-based sleep disorders center. Control subjects were selected from the general population. PATIENTS AND CONTROLS: There were 344 OSAS patients on whom there was utilization data for the period of the study. They were matched to controls from the general population by gender, age, and geographic location. MEASUREMENTS AND RESULTS: The difference in physician claims between the patients and their matched controls two years after diagnosis and treatment ($174+/-32.4 (SE) per year in Canadian dollars) was significantly less than the difference in the year before diagnosis ($260+/-35.7 (SE), p=0.038). Examining the subgroups of patients adhering (PAT) or not adhering (PNAT) to treatment revealed that the changes were only significant in the patients adhering to treatment. Hospital stays for the entire OSAS group decreased from 1.27 days+0.25(SE) per patient per year one year before diagnosis to 0.54+0.13 per patient per year (p=0.01). The changes in the PAT group (1.25+0.28 per patient per year one year before diagnosis to 0.53+0.14 per patient per year (p=0.034) were significant while in the PNAT group they were not. CONCLUSIONS: Adherence to treatment in patients with OSAS results in a significant reduction in physician claims and hospital stays.

Upper airway resistance syndrome: effect of nasal dilation, sleep stage, and sleep position.

BACKGROUND: The upper airway resistance syndrome (UARS) is one of the mild variants of obstructive sleep disordered breathing. Nasal obstruction is proposed as one of the mechanisms that lowers intrapharyngeal pressure and hence increases airway collapsibility. OBJECTIVE: We evaluated the effect of external nasal dilation and sleep position on sleep in UARS. METHOD: A double blind, randomized, controlled study with a crossover design (using therapeutic and placebo dilators) was conducted in 18 consecutive patients with UARS. Each patient had two overnight sleep studies one to two weeks apart. Cardiorespiratory parameters (AHI, percentage of time that SaO2 was more than 2% below awake [desaturation time] and mean overnight heart rate), sleep architecture (sleep stages, sleep efficiency, and arousal index), and body position were determined. RESULTS: Application of the external nasal dilator resulted in a significant increase in the nasal cross-sectional area (p < 0.001). Treatment reduced stage 1 sleep (as a percent of total sleep time) from 8.6 +/- 0.8% to 7.1 +/- 0.7 (SEM), p = 0.034). Desaturation time was significantly lower with treatment (12.2 +/- 2.2% on placebo versus 9.1 +/- 1.3 on treatment, p = 0.04). There were no additional significant effects on the cardiorespiratory parameters, sleep architecture, or MSLT when the entire night was examined. Controlling for interactions of sleep stage and position and treatment we found that treatment reduced desaturation time (p = 0.03) but not AHI or arousal index. AHI was significantly lower in the lateral position compared to the supine (p = 0.0001) and in NREM sleep compared to REM (p = 0.001). Desaturation time was significantly lower on the lateral compared to the supine position (p = 0.002) and in NREM sleep compared to REM (p = 0.006). Arousal index was highly dependent on sleep stage (p = 0.0001): the index was higher in stage 2 compared to slow wave sleep and REM. Sleep position and treatment had no significant effect on arousals. CONCLUSIONS: External nasal dilation reduced stage 1 sleep, an indirect marker of disrupted sleep, and desaturation time. There were no additional effects on sleep architecture or sleep disordered breathing. Both sleep position and sleep stage had a significant effect on sleep disordered breathing in UARS.

Decision making in obstructive sleep-disordered breathing: putting It all together

Obstructive sleep-disordered breathing consists of a spectrum ranging from the upper airway resistance syndrome to complete apnea. Although this disorder is relatively common, it is still under-recognized, resulting in a significant increase in morbidity and mortality. This article describes the rationale for treating this disorder. Then, using the best available evidence, develops a systemic approach to the problem, covering recognition, diagnosis, and treatment.

Health care utilization in the 10 years prior to diagnosis in obstructive sleep apnea syndrome patients.

Obstructive sleep apnea syndrome (OSAS) patients may have symptoms for years prior to recognition of their disorder, or they may be treated for the associated comorbidities. We hypothesized that such patients would be heavy consumers of health care resources for several years prior to diagnosis. We therefore compared health service utilization for a 10-year interval prior to diagnosis of 181 OSA patients to those of randomly selected age-, gender-, and geographically matched controls from the general population. OSAS patients used approximately twice as many health care services (as defined by physician claims and overnight stays in hospital) in the 10 years prior to their initial diagnostic evaluation for apnea. Physician claims for the OSA patients totaled $686,365 ($3972 per patient), compared to $356,376 ($1969 per patient) for the controls for the 10-year period examined in this study. Use of health services was significantly higher in 7 of 10 years prior to diagnosis. The OSAS patients also had more overnight hospitalizations: they spent 1118 nights (6.2 per patient) in hospital vs 676 nights (3.7 per patient) for controls in the decade prior to diagnosis. We conclude that by the time patients are finally diagnosed for sleep apnea, they have already been heavy users of health services for several years. It is possible that our findings reflect not OSAS per se, but the presence of some of the risk factors that predispose to OSAS, such as obesity, alcohol usage and perhaps tobacco consumption.

The validity of acid-fast smears of gastric aspirates as an indicator of pulmonary tuberculosis.

SETTING: A tuberculosis referral hospital in Canada. OBJECTIVE: To determine the validity of acid-fast (AFB) smears of gastric aspirates (GA) in the diagnosis of pulmonary tuberculosis, and to assess the prevalence of nontuberculous mycobacteria (NTM) in GA isolates from such patients. DESIGN: A retrospective case review of our experience with AFB smears (Kinyoun) and cultures of GA and sputum over a 3-year period. RESULTS: From 1994 to 1996 inclusive, 1155 GA were performed in 889 patients. Mycobacteria were cultured from 109 (9%) GA. Thirteen of these were positive on smear (sensitivity 19%). All GA that were positive on smear were culture positive for Mycobacterium tuberculosis. There were no false positive smears (specificity 100%). The sensitivity and specificity of the sputum smear were 45% and 99%, respectively. Of the 96 culture positive, smear negative GA, 54 grew M. tuberculosis and 42 grew an NTM. Of 13 patients who had sputum and GA studied coincidentally, and in whom the sputum was both smear and culture positive, the GA culture was positive in 13 and the smear was positive in eight (66%). CONCLUSION: AFB smear of GA is a relatively insensitive but highly specific indicator of pulmonary tuberculosis warranting institution of antituberculosis treatment. Gastric AFB smear positivity appears to reflect a high bacillary burden within the respiratory tract.

Utility of gastric aspirates in screening for pulmonary tuberculosis in high risk subjects:The Manitoba experience.

BACKGROUND: Although gastric aspirates (GA) are one of the recommended screening procedures for asymptomatic individuals at high risk for developing tuberculosis (TB), little data exist on the utility of GA for this indication. OBJECTIVE: To determine the utility of GA as a screening tool in asymptomatic subjects who are at high risk for developing pulmonary TB. PATIENTS AND METHODS: The study population's clinical, radiographical and Mantoux skin test findings were correlated with a laboratory database of all patients who underwent GA in 1994. Subjects included in the study were those at high risk of developing TB, ie, immigrants placed under surveillance for TB postlanding in Canada (surveillance foreign-born), other foreign-born individuals from high prevalence countries, Status Indians and close contacts of patients with active pulmonary TB. RESULTS: Four hundred and twelve GAs were performed in 318 patients. Complete data were available in 243 patients. Canadian-born persons who were not Status Indians and foreign-born persons from nonendemic areas (n=37) were excluded. The remaining 206 patients had 261 GAs performed (1.27±0.7 per subject). This group consisted of surveillance foreign-born (n=57), other foreign-born (n=110) and Status Indians (n=39). Fifty-three (26%) were symptomatic and 153 (74%) were asymptomatic. Ninety-eight had a normal chest radiograph, and 108 had an abnormal chest radiograph. Fourteen subjects (26%) in the symptomatic group had Mycobacterium tuberculosis isolated from their GA versus one (0.65%) in the asymptomatic group (P<0.001). One subject (1%) in the normal chest radiograph group versus 14 (12%) in the abnormal chest radiograph group (P=0.005) had M tuberculosis isolated from their GA. Thirty-six subjects were both symptomatic and had abnormal chest radiographs. In this group, 12 (33%) had M tuberculosis isolated from their GA, while none of the patients who were asymptomatic and had normal chest radiographs had a positive M tuberculosis culture. There was no difference in the yield of GA between Mantoux skin test-positive and Mantoux skin test-negative groups. CONCLUSIONS: GAs have a low yield when used to screen asymptomatic high risk subjects. The results suggest that screening of asymptomatic individuals or those with normal chest radiographs may not be warranted. This will spare many asymptomatic subjects the discomfort of undergoing the procedure and produce a significant cost saving.

Susceptibility of LDL to oxidative stress in obstructive sleep apnea.

Cardiovascular diseases are more common in patients with obstructive sleep apnea (OSA) than in the general population. We hypothesized that severe hypoxemia during sleep in these patients may cause an imbalance between reactive oxygen species and the antioxidant reserve that is important for the detoxification of these molecules. We tested the hypothesis that low-density lipoproteins (LDL) in hypoxic OSA patients may be more susceptible to oxidative stress than LDL of nonhypoxic OSA patients and normal controls. Fifteen OSA patients were included in this study, six with severe hypoxia (hypoxic group) who spent more than 10 minutes during sleep with SaO2 < 85% (mean 96 minutes), and nine OSA patients (nonhypoxic group) who spent less than 10 minutes during sleep with SaO2 < 85% (mean 1.1 minutes). Six healthy nonsmoking males of the same age group were included as a control group. The susceptibility of each individual's LDL to oxidative stress was examined after free-radical challenge in vitro by assessing changes in levels of conjugated dienes. The LDL in OSA patients with severe hypoxia was not more susceptible to oxidative stress compared to the LDL of nonhypoxic OSA patients and normal controls. After 6 hours of exposure to an oxidative agent, the changes in the mean conjugated diene were not different among the three groups (p = 0.75). The time required to reach 50% of maximal absorbance was also not different, p = 0.199. Glutathione peroxidase and catalase activities in red blood cells in the hypoxic and nonhypoxic patient groups were not significantly different. One night of CPAP therapy in each patient group did not significantly change the level of the antioxidant enzymes. Our results did not show any difference in the susceptibility to oxidative stress between hypoxic and nonhypoxic OSA patients and normal controls.