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.

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.

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.

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.

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.

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.