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Biomedical subjects

T Akashiba

Publications and source records attributed to T Akashiba.

At least 19 recordsLinked to original sources
PubMed1999

Effects of nasal continuous positive airway pressure on pulmonary haemodynamics and tissue oxygenation in patients with obstructive sleep apnoea.

We investigated the acute effects of nasal continuous positive airway pressure (CPAP) on pulmonary haemodynamics and tissue oxygenation in eight men with obstructive sleep apnoea (OSA) by means of right heart catheterization. They were tested at four dosage levels of nasal CPAP: 0, 5, 10, and 15 cmH2O. Nasal CPAP significantly reduced the cardiac index at the 10 and 15 cmH2O doses. The mean pulmonary artery pressure was significantly elevated with 10 and 15 cmH2O, and pulmonary capillary wedge pressure was significantly increased with 15 cmH2O of nasal CPAP. Pulmonary vascular resistance was significantly increased with 10 cmH2O of nasal CPAP. The 5 cmH2O dose of nasal CPAP did not affect significantly these parameters. Mixed venous oxygen tension was unchanged at any pressure. We conclude that tissue oxygenation was maintained in the OSA patients during administration of nasal CPAP, even though a high CPAP clearly affected pulmonary haemodynamics.

Adult↗
PubMed1998

Acute effects of nasal continuous positive airway pressure on 24-hour blood pressure and catecholamines in patients with obstructive sleep apnea.

To assess the acute effects of nasal continuous positive airway pressure (CPAP) on the 24-hour blood pressure and the secretion of catecholamines in urine and plasma, we investigated the changes in the 24-hour blood pressure and urinary and plasma concentrations of epinephrine (E) and norepinephrine (NE) in 26 men with obstructive sleep apnea (OSA) with and without nasal CPAP. Nasal CPAP resulted in significant decreases in the daytime diastolic pressure (from 86 +/-16 mmHg to 83+/-12 mmHg), the nighttime diastolic pressure (from 81+/-12 mmHg to 77+/-9 mmHg) and the nighttime systolic pressures (from 125+/-15 mmHg to 120+/-10 mmHg). There was no significant difference between patients with and without CPAP in the daytime or nighttime urinary E level, but patients who received CPAP showed a significant decrease in daytime urinary NE level (from 156+/-112 microg/14h to 119+/-101 microg/14h) and nighttime urinary NE level (from 143+/-91 microg/10h to 112+/-65 microg/10h). The morning plasma level of NE also decreased (from 371+/-181 pg/ml to 273 +/-148 pg/ml) in patients who received nasal CPAP (p<0.02), but the plasma level of E remained unchanged. There were no correlations between PSG parameters and the reductions in blood pressure and the catecholamine levels induced by nasal CPAP. These findings suggest that OSA contributes, at least in part, to the development of systemic hypertension by increasing sympathetic nervous activity.

Biomarkers↗
PubMed1998

[Long-term effects of nasal continuous positive airway pressure on pulmonary function and blood gas data in patients with obstructive sleep apnea syndrome].

To evaluate the long-term effects of nasal continuous positive airway pressure (NCPAP) on pulmonary function and blood gas levels in patients with obstructive sleep apnea syndrome (OSAS), we examined the pulmonary functions and blood gases in 25 male patients with OSAS before and after NCPAP treatment. After 22 months of treatment (titration: 13 cm H2O), no significant changes were observed in the patients' spirograms, pulmonary gas volumes, or diffusion capacity. However, PaO2 levels increased significantly (p < 0.01), from 73.8 mmHg to 79.5 mmHg; PaCO2 levels decreased significantly (p < 0.05), from 45.6 mmHg to 44.2 mmHg; and A-aDO2 levels also decreased significantly (p < 0.05), from 18.7 mmHg to 15.0 mmHg. The patients were divided into a hypoventilated group (PaCO2 > 45 mmHg; 11 cases) and normoventilated group (PaCO2 < or = 45 mmHg; 14 cases). After NCPAP treatment, increased PaO2 and decreased PaCO2 levels were observed in the hypoventilated group, and increased PaO2 and decreased A-aDO2 levels were observed in the normoventilated group. These results suggest that long-term NCPAP treatment improves gas exchange in OSAS patients without influencing the results of pulmonary function tests.

Adult↗
PubMed1998

[Sleep apnea syndrome in Japan: analysis of pathophysiology and nasal continuous positive airway pressure effectiveness].

Forty eight Japanese sleep apnea syndrome (SAS) patients, whose apnea-hypopnea index (AHI) was more than 30 times/hr. from 5 university hospitals (46 males, 2 females) were enrolled in this study to analyze the characteristics of the disorder and the effectiveness of nasal continuous positive airway pressure (nCPAP) effectiveness. Although the severity of excessive daytime sleepiness (EDS), depressive state, and ventricular premature beats caused by SAS seemed milder in Japanese than reported Caucasian patients, the prevalences of hypertension and glucose intolerance were quite high: 50 and 30% respectively. Treatment with nCPAP for 3 months was completed in 41 of 48 enrollees, a compliance rate of 85.4%, which was substantially higher than studies from Western countries. nCPAP treatment normalized about 50% of hypertensive patients and more than half of glucose intolerant patients. Moreover, EDS, driving ability, the severity of arrhythmia, and so forth were all improved with nCPAP. We, therefore, conclude that 1) SAS could differ between Japanese Caucasians in terms of clinical features resulting from SAS and 2) treatment with nCPAP is effective and should be considered as first-line treatment for patients with moderate to severe SAS, as reported in Western countries.

Adult↗
PubMed1995

Daytime hypertension and the effects of short-term nasal continuous positive airway pressure treatment in obstructive sleep apnea syndrome.

Daytime blood pressure (BP) in 31 male patients with obstructive sleep apnea syndrome (OSAS) was measured and the effects of nasal continuous positive airway pressure (CPAP) treatment on daytime BP were studied. Subjects were 48 +/- 10 (mean +/- SD) years old and weighed 80 +/- 13 kg. The mean systolic BP and diastolic BP were 135 +/- 15 mmHg and 88 +/- 14 mmHg, respectively and daytime hypertension was present in 12 (38%) subjects. Apnea index (AI) and the lowest oxygen saturation during sleep were significantly more severe in the hypertensive (HT) than in the non-hypertensive (NHT) patients (p < 0.05). AI was significantly correlated with diastolic BP (p < 0.05) and the mean and lowest oxygen saturation during sleep were significantly correlated with both systolic (p < 0.05) and diastolic BP (p < 0.01). After nasal CPAP treatment for two weeks, both systolic and diastolic BP were significantly reduced; the former from 135 +/- 15 mmHg to 126 +/- 10 mmHg (p < 0.005) and the latter from 88 +/- 14 mmHg to 78 +/- 6 mmHg (p < 0.001). These data form direct evidence that daytime hypertension is partially induced by OSAS and is reversible with nasal CPAP treatment.

Circadian Rhythm↗
PubMed1995

[Non-surgical treatment of obstructive sleep apnea].

We studied the clinical usefulness of nasal continuous positive airway pressure (CPAP) treatment of obstructive sleep apnea syndrome (OSAS). The subject were 56 men with OSAS. Their mean age, apnea index, and SaO2 were 51 +/- 8 years, 48 +/- 18, and SaO2 were 51 +/- 8 years, 48 +/- 18, and 81 +/- 7%, respectively. After titration of CPAP, they underwent nasal CPAP treatment at home every night. Symptoms, blood pressure, pulmonary function, compliance with the prescription and complications of treatment were evaluated every one or two months in an outpatient clinic. Blood pressure decreased significantly from 135 +/- 15 mmHg (systolic) and 88 +/- 14 mmHg (diastolic) to 126 +/- mmHg (systolic) and 78 +/- 6 mmHg (diastolic) in 51 cases after two weeks of treatment. No significant change in pulmonary function except for blood gases was observed after longterm treatment. Excessive daytime sleepiness disappeared and sleep quality improved after treatment in most cases. Thirty-six of 43 patients continued to use nasal CPAP for 34 +/- 16 months and 33% complied with the prescription. Although nasal mask discomfort and dryness of the nose and mouth occurred in several cases, there were no serious complications. These findings suggest that nasal CPAP is useful for treatment of patients with OSAS. However, the problem remains that the cost of nasal CPAP is not reimbursed by the public health insurance system in Japan.

Adult↗
PubMed1994

[Organ failure due to hypoxemia, and effects of oxygen therapy--effects of hypoxemia on pulmonary hemodynamics, and improvement with oxygenation].

To investigate pulmonary hemodynamics in patients with chronic respiratory failure, we performed right heart catheterization and also examined the effects of oxygen inhalation. Thirty-three patients were studied. Their mean age was 65 +/- 10 years, and FEV1.0% and PaO2 on room air were 47 +/- 16% and 63 +/- 14 mmHg, respectively. mPAP was 27 +/- 10 mmHg, and 26 (78%) had pulmonary hypertension. Although PVR was abnormally high, CI and PCWP were within normal limits. PaO2 was significant Significantly correlated with mPAP and PVR. Although oxygen inhalation (28%) for 30 minutes significantly changed PaO2, PaCO2, and PvO2, it did not significantly affect mPAP, PVR, CI, or PCWP. These results suggest that short-term oxygen inhalation does not affect pulmonary hemodynamics in patients with chronic respiratory failure. Radionuclid ventriculography was also done to evaluate cardiac function in 16 patients before and after home oxygen therapy (HOT). Both right ventricular ejection fraction (RVEP) and left ventricular ejection fraction (LVEF) were significantly increased by HOT, and the significant correlation between RVEF and LVEF that had been observed before HOT disappeared. These results suggest cardiac function improved and that the interdependence between the right and left ventricle was eliminated by HOT.

Aged↗
PubMed1993

Genetics and obstructive sleep apnea syndrome: a study of human leukocyte antigen (HLA) typing.

To investigate the possible influence of genetics in subjects with obstructive sleep apnea syndrome (OSAS), HLA-A, B, C, and DR antigens were studied in 32 Japanese subjects with OSAS. The frequency of HLA-A2 antigen was markedly increased in the patients with OSAS compared with normal controls (81.3% vs 40.6%) and compared with the Japanese population (40.7%), Pc < 0.035 and Pc < 0.007, respectively. HLA-B39 was found more frequently in OSAS patients than in the Japanese population (Pc < 0.018), but not in the controls. No significant deviation was observed in the frequencies of HLA-C and DR antigens between the OSAS patients and the controls. We conclude that genetics is important in the development of OSAS.

Adult↗
PubMed1993

[Improvement of biventricular heart failure in a case of obstructive sleep apnea syndrome by nasal CPAP therapy].

A 42-year-old male patient with obstructive sleep apnea syndrome (OSAS) suffering from biventricular heart failure is reported. He had been treated for OSAS with conventional therapy. However, he complained of severe dyspnea in association with extreme weight gain and general edema. Therefore, he was admitted to our department. He weighed 168 kg on admission, and marked edema was observed. Chest film revealed significant dilatation of the cardiac silhouette and pleural effusion. PaO2 was 37 mmHg and PaCO2 was 66 mmHg. Polysomnography showed an apnea index of 58.3 and severe oxygen desaturation during sleep. Right heart catheterization showed elevation of mean pulmonary artery pressure mPAP: 55 mmHg) and pulmonary capillary wedge pressure (Pcwp: 33 mmHg) suggesting biventricular heart failure. Digitalization and diuretic therapy were immediately initiated. In addition, nasal CPAP was applied to this patient during sleep, and sleep apnea and oxygen desaturation were almost completely reversed. Significant diuresis was observed, and blood gas data and sleep disturbance were improved. Fifty-nine days after admission, his weight had decreased to 96 kg, and mPAP and Pcwp decreased to 32 and 23 mmHg, respectively. This case demonstrates that nasal CPA is an effective tool for the treatment severe OSAS patients.

Adult↗
PubMed1993

[Traffic accidents in obstructive sleep apnea patients and effect of nasal CPAP treatment].

We studied the traffic accident rates and daytime sleepiness in obstructive sleep apnea syndrome (OSAS) patient, and evaluated the effectiveness of long-term nasal CPAP treatment. Traffic accidents were observed in 42% of 14 male OSAS patients (46 +/- 7 years old) and near-miss accidents were also observed in 64% during the past three years. Stanford Sleepiness Scale showed 4.7 +/- 1.0, suggesting marked excessive daytime sleepiness (EDS). During NCPAP treatment for 11 +/- 9 months, no traffic and near-miss accidents were reported. After NCPAP treatment, SSS decreased to 2.0 +/- 0.8, and the score of Uchida-Kraeplin test for the evaluation of working ability increased significantly. These results suggest the improvement of EDS and working ability following NCPAP treatment. We conclude that OSAS patients have the tendency of daytime sleepiness and high traffic accidents rates, and NCPAP treatment is effective to improve such problems.

Accidents, Traffic↗
PubMed1992

[Pulmonary function and exercise tolerance in patients treated with bone marrow transplantation (BMT)].

We assessed pulmonary function and exercise tolerance in 10 BMT patients. Their underlying disorders were as follows; chronic myeloid leukemia 5 cases, acute lymphoblastic leukemia 2 cases, aplastic anemia, acute myeloid leukemia and non-Hodgkin's lymphoma one case each. Their mean age was 26 +/- 9 years old. When the patients were healthy and free of serious complications and anemia, arterial blood gas examination, pulmonary function tests and incremental treadmill exercise test were examined repeatedly. Although %VC and FEV1.0% kept within normal range, PaO2 at rest, %DLCO, VO2max, VO2max/kg and O2-pulsemax remained low at one year after BMT. There were significant correlations between VO2max and O2-pulsemax [r = 0.955 (p < 0.001)], %VC [r = 0.758 (p < 0.02)], VE/VO2max [r = -0.749 (p < 0.02)] and delta SaO2/VO2/kg [r = -0.731 (p < 0.02)], suggesting that exercise intolerance in BMT patients may be based on both cardiac and gas exchange abnormalities. To evaluate cardiac dysfunction, we compared exercise parameters obtained at an exercise level of 75% predicted heart rate max in five age-matched normal subjects to those in six BMT patients who did not demonstrate desaturation during exercise. As a result, the mean values of VO2max/kg and O2-pulse/m2 in BMT patients were significantly lower than those in normal subjects, suggesting that cardiac dysfunction may be due to insufficiency of stroke volume during exercise. It is concluded that exercise intolerance in BMT patients may be mainly due to cardiac dysfunction.

Adolescent↗