Primary pulmonary hypertension with central sleep apnea: sudden death after bilevel positive airway pressure therapy. (1/185)

An obese 23-year-old man with sleep-disordered breathing and primary pulmonary hypertension (PPH) had been administered oral beraprost sodium, anticoagulant warfarin, and home oxygen therapy, at another hospital as treatment for the PPH, but he had not experienced any symptomatic improvement. The patient had a body mass index of 32.4kg/m2, and complained of fatigue, shortness of breath on exertion, excessive daytime sleepiness, and snoring. Arterial blood gas analysis showed a PaO2 and a PaCO2 of 70.9 and 31.2mmHg, respectively. A polysomnographic study revealed central sleep apnea with an apnea-hypopnea index (AHI) of 29.7episodes/h. The patient showed improvement of daytime sleepiness after starting nocturnal nasal bilevel positive airway pressure (BiPAP) therapy for the central sleep apnea, but his pulmonary hypertension, measured in the daytime, worsened. The patient died suddenly while walking to the bathroom in the morning 1 month after initiation of BiPAP therapy. It is necessary to consider the possibility of sudden death when nasal BiPAP therapy is given to a PPH patient with central sleep apnea.  (+info)

Ventilatory response to CO2 re-breathing before and after nocturnal nasal intermittent positive pressure ventilation in patients with chronic alveolar hypoventilation. (2/185)

Long-term nocturnal nasal intermittent positive pressure ventilation (NIPPV) has beneficial effects on daytime PaCO2 in patients with chronic alveolar hypoventilation. Our aim was to investigate if these beneficial effects are related to improved respiratory drive as measured by ventilatory response to CO2. In 17 hypoventilated patients (mean age 62 years) we obtained daytime arterial blood gases, nocturnal transcutaneous oxygen saturation, nocturnal transcutaneous PaCO2 ventilatory response to CO2 re-breathing, spirometry and indices of respiratory muscle strength before and after 9 months of NIPPV. Patients served as their own controls. After 9 months of NIPPV day-time PaCO2 decreased from 7.1 kPa to 6.3 kPa, (P<0.001) and PaO2 increased from 8.1 kPa to 9.3 kPa, (P<0.01). The changes in morning and daytime PaCO2 and in nocturnal transcutaneous oxygen saturation were significantly correlated to the changes in several variables derived from the ventilatory response to CO2 re-breathing. In patients with substantial improvement in daytime PaCO2 we found significant improvements in ventilatory response to CO2 re-breathing. The present study confirms the beneficial effect of long-term NIPPV on daytime arterial blood gases. The results are consistent with the hypothesis that the improvement of daytime PaCO2 is related to improved respiratory drive observed after NIPPV.  (+info)

Overnight shift from obstructive to central apneas in patients with heart failure: role of PCO2 and circulatory delay. (3/185)

BACKGROUND: Obstructive (OSA) and central sleep apnea (CSA) can coexist in patients with congestive heart failure (CHF). However, the reason why OSA events occur at one time and CSA events at another has not been determined. We hypothesized that a change in PCO(2) would be associated with an alteration in apnea type: a decrease in PCO(2) should lead to CSA. METHODS AND RESULTS: To test this hypothesis, we evaluated minute ventilation (V(I)), transcutaneous PCO(2) (PtcCO(2)), circulation time, and periodic breathing cycle length during overnight polysomnography in 12 patients with CHF and coexisting OSA and CSA. V(I) was significantly greater (mean+/-SEM, 9.4+/-1.3 versus 8.0+/-0.9 L/min; P:<0.05) and PtcCO(2) was lower (39.4+/-1.0 versus 41.9+/-1.1 mm Hg, P:<0.01) during episodes of CSA than of OSA. These changes were associated with significant lengthening of circulation time (23.6+/-3.7 versus 21.1+/-3.6 seconds, P:<0.01) and periodic breathing cycle length (53.7+/-3.5 versus 49.6+/-2.9 seconds, P:<0.01). In addition, the proportion of obstructive events decreased (from 68.5+/-11.4% to 22.5+/-7.2%, P:<0.001) and of CSA events increased (from 31.5+/-11.4% to 77.5+/-7.2%, P:<0.001) from the first to the last quarter of the night in association with a significant decrease in PtcCO(2) (from 42.6+/-0.9 to 40.8+/-0.9 mm Hg, P:<0.01). CONCLUSIONS: In patients with CHF, the shift from OSA to CSA is associated with a reduction in PCO(2). This appears to be related to an overnight deterioration in cardiac function as suggested by the concurrent lengthening of circulation time. Therefore, in CHF patients, alterations in cardiac function may influence apnea type.  (+info)

Familial adult onset primary alveolar hypoventilation syndrome. (4/185)

A 41-year-old man fell into type II respiratory failure after catching a cold, and became dependent on a respirator. Chest radiography showed no abnormalities and the hyperventilation test showed improved arterial blood gas findings. His sleep study showed marked nocturnal desaturation due to hypopnea and apnea with a decrease of thoracic and abdominal movement during sleep. Therefore, we diagnosed him as primary alveolar hypoventilation syndrome (PAH). Seven years previously, his 2-year elder sister had suffered from similar respiratory failure during her second pregnancy and had been diagnosed as PAH. While myopathy was suspected in both cases, attenuation of muscle strength was slight and it appeared not to be the main cause of alveolar hypoventilation. Since medication was not effective in each case, they underwent non-invasive positive pressure ventilation (NIPPV). While sustained mild hypercapnia remained during the daytime, it improved their respiratory failure. To our knowledge, this is the first study of familial adult onset PAH.  (+info)

The effect of non-invasive positive pressure ventilation (NIPPV) on cognitive function in amyotrophic lateral sclerosis (ALS): a prospective study. (5/185)

OBJECTIVES: Neuropsychological investigations have shown a degree of cognitive dysfunction in a proportion of non-demented patients with ALS. Respiratory muscle weakness in ALS can lead to nocturnal hypoventilation, resulting in sleep disturbance and daytime somnolence. Sleep deprivation of this type may cause impairments in cognitive function, but this has not been formally evaluated in ALS. METHODS: Cognitive functioning was evaluated in nine patients with ALS with sleep disturbance caused by nocturnal hypoventilation (NIPPV group), and in a comparison group of 10 similar patients without ventilation problems (control group). The NIPPV group then started non-invasive positive pressure ventilation (NIPPV) at night. After about 6 weeks, change in cognitive function was evaluated. RESULTS: Statistically significant improvement in scores on two of the seven cognitive tests was demonstrated in the NIPPV group postventilation, and a trend towards significant improvement was found for two further tests. Scores in the control group did not improve significantly for these four tests, although an improvement was found on one other test. CONCLUSIONS: Nocturnal hypoventilation and sleep disturbance may cause cognitive dysfunction in ALS. These deficits may be partially improved by NIPPV over a 6 week period. This has important implications for investigations of both cognitive dysfunction in non-demented patients with ALS, and the effect of ventilation on quality of life.  (+info)

Benefit of atrial pacing in sleep apnea syndrome. (6/185)

BACKGROUND: Many patients with sleep apnea syndrome have nocturnal bradycardia, paroxysmal tachyarrhythmias, or both, which can be prevented by permanent atrial pacing. We evaluated the effect of using cardiac pacing to increase the heart rate during sleep in patients with sleep apnea syndrome. METHODS: We studied 15 patients (11 men and 4 women; mean [+/-SD] age, 69+/-9 years) with central or obstructive sleep apnea who had received permanent atrial-synchronous ventricular pacemakers for symptomatic sinus bradycardia. All patients underwent three polysomnographic evaluations on consecutive nights, the first night for base-line evaluation and then, in random order, one night in spontaneous rhythm and one in dual-chamber pacing mode with atrial overdrive (basic rate, 15 beats per minute faster than the mean nocturnal sinus rate). The total duration and number of episodes of central or obstructive sleep apnea or hypopnea were analyzed and compared. RESULTS: The mean 24-hour sinus rate during spontaneous rhythm was 57 +/- 5 beats per minute at base line, as compared with 72 +/- 3 beats per minute with atrial overdrive pacing (P<0.001). The total duration of sleep was 321 +/- 49 minutes in spontaneous rhythm, as compared with 331 +/- 46 minutes with atrial overdrive pacing (P=0.48). The hypopnea index (the total number of episodes of hypopnea divided by the number of hours of sleep) was reduced from 9 +/- 4 in spontaneous rhythm to 3 +/-3 with atrial overdrive pacing (P<0.001). For both apnea and hypopnea, the value for the index was 28 +/- 22 in spontaneous rhythm, as compared with 11 +/- 14 with atrial overdrive pacing (P<0.001). CONCLUSIONS: In patients with sleep apnea syndrome, atrial overdrive pacing significantly reduces the number of episodes of central or obstructive sleep apnea without reducing the total sleep time.  (+info)

A case of diabetes, deafness, cardiomyopathy, and central sleep apnea: novel mitochondrial DNA polymorphisms. (7/185)

We describe a case of diabetes mellitus complicated by neurosensory hearing loss, cardiomyopathy, and sleep apnea syndrome. A 48-year-old man who was admitted for treatment of a lacerated tendon of the right shoulder was also found to require preoperative control of diabetes, a condition that had been diagnosed 4 years earlier. The family pedigree suggested maternal inheritance of diabetes. The patient also had neurosensory hearing loss and the central type of sleep apnea syndrome. His myocardium was hypertrophic and the ultrastructural analysis showed morphologically abnormal mitochondria. On the basis of the apparent characteristic manifestations, we speculated that he had a mitochondrial disease. To elucidate the responsible mutation of mitochondrial DNA, we sequenced the patient's entire mitochondrial DNA derived from blood leukocytes and found 40 sequence variants. Three of those, 5466 A/G, 7912 G/A, and 10601 T/C, have not yet been reported. Nine of the 40 variants were accompanied by an amino acid replacement, including 5466 A/G. Although we could not determine the most significant mutation, the variants of mitochondrial DNA may have been associated with this patient's unusually variable clinical manifestations.  (+info)

Congenital central hypoventilation syndrome: a novel mutation of the RET gene in an isolated case. (8/185)

Recently, a few genetic abnormalities were identified in congenital central hypoventilation syndrome (CCHS or Ondine's curse). CCHS is often associated with other neurocristopathies, especially with Hirschsprung's disease (HSCR). Mutations of the genes involved in the receptor tyrosine kinase RET (REarranged during Transfection) (RET)-glial cell line-derived neurotrophic factor (GDNF) and/or endothelin 3 (EDN3)-endothelin receptor-B (EDNRB) signaling pathway have been found in some of HSCR patients. In this study, we analyzed candidates for HSCR, namely the RET, GDNF, EDN3 and EDNRB genes in three isolated CCHS patients to confirm the hypothesis that some CCHS patients have a common genetic abnormality with patients having HSCR or other neurocristopathies. We found a novel R114H mutation of the RET gene in one patient. The R114H mutation is unlikely to be a polymorphism and appears to be associated with CCHS. In addition, we also examined the HOX11L2 (RNX) gene, for which knock-out mice showed CCHS-like syndrome in these isolated CCHS patients and did not detected any mutation. Further cases should be analyzed for more candidates to clarify the pathophysiology of CCHS.  (+info)