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Biomedical subjects

M Oswald

Publications and source records attributed to M Oswald.

48 records · Page 3Linked to original sources
PubMed1990

Treatment of patients with isolated axillary nodal metastases from an occult primary carcinoma consistent with breast origin.

The records of 42 patients who had axillary metastases compatible with a clinically occult breast primary were reviewed. Forty patients had mammography performed as part of their evaluations. Mastectomy yielded the primary tumor in one of 13 patients; biopsy yielded positive results in one of five. Among the 29 patients who did not undergo mastectomy, 16 received breast irradiation, and 13 were simply observed for signs of the primary tumor. For the patients who did not undergo mastectomy, the 5-year actuarial risk for appearance of a primary was 17% in the irradiated group versus 57% in the nonirradiated group (P = 0.06). Patterns of failure are correlated with stage and local and systemic therapy. The results affirm our belief that patients with axillary metastases histologically consistent with breast tumor should be treated identically to patients with similar nodal stages and proven breast primaries.

Adult↗
PubMed1990

Should patients have right heart catheterization prior to long-term oxygen treatment?

The presence of pulmonary hypertension (PH) is not an obligatory prerequisite for prescribing long-term oxygen therapy (LTO) in patients with chronic obstructive pulmonary disease (COPD), at least when PaO2 is repeatedly less than 55 mmHg in a stable state of the disease. It is generally accepted that LTO is indicated in patients whose PaO2 is in the range 55-59 mmHg, but exhibiting polycythaemia, "cor pulmonale", and (or) PH. The clinical signs of "cor pulmonale" occur late and the noninvasive diagnosis of PH is not yet satisfactory; it ensues that right heart catheterization is useful in these patients, before prescribing LTO. Pulmonary hypertension is probably the most important consequence of long-standing hypoxaemia and, in our opinion, the presence and the degree of PH should be assessed in every patient before starting such a heavy therapy as LTO.

Cardiac Catheterization↗
PubMed1990

Drug therapy of sleep-related hypoxaemia.

In patients with chronic obstructive pulmonary disease (COPD) exhibiting daytime hypoxaemia, a worsening of the latter occurs during sleep, particularly during REM sleep. The most efficient therapy of this sleep-related hypoxaemia is the nocturnal administration of O2 at a flow rate of 1.5-3 l/min. An alternative therapy, when daytime hypoxaemia is not too severe (PaO2 greater than 55 mmHg), is the use of almitrine (100 mg/day), a drug which improves daytime hypoxaemia in most COPD patients. The improvement of sleep hypoxaemia with almitrine is related to the increased daytime PaO2 and cannot be considered as a specific effect of almitrine on sleep-related respiratory events. It must be emphasized that almitrine is ineffective in about 25% of COPD patients ("nonresponders") and that almitrine can be used with conventional O2 therapy in patients with severe hypoxemia (daytime PaO2 less than 55 mmHg).

Almitrine↗
PubMed1989

[Development of pulmonary arterial hypertension in chronic obstructive bronchopneumopathies].

In chronic obstructive bronchopneumopathies (COBP), pulmonary artery hypertension (PAH) is usually mild but may markedly intensify during episodes of acute respiratory failure, muscular exercise, and sleep, PAH may, even if of low level, lead to right heart failure. The prognostic value of PAH and its degree in COBP patients has been well established by a number of recent studies. Chronologic changes in pulmonary artery pressure (PAP) tend to be minimal in the majority of COBP patients (of the order of +0.5-0.6 mm Hg/year in most studies). However, in a minority of patients (about 30%) pulmonary hypertension worsens seriously due to progressive deterioration of arterial blood gases. Longterm oxygen therapy (LOT) for 16 h/day rarely serves to normalize PAP but may reverse the progress of pulmonary hypertension, particularly in patients with progressive aggravation thereof. Recent studies have made it clear that LOT has beneficial hemodynamic effects in a relatively large percentage of COBP patients with PAH.

Heart Failure↗
PubMed1989

Evolution of pulmonary haemodynamics in COLD patients under long-term oxygen therapy.

The North-American Trial (NOTT) and the British MRC study clearly indicated that long-term oxygen therapy (LTO) increases the survival rate of patients with severe chronic obstructive long disease (COLD), but O2 must be given for more than 15 h/24 h. At present OT is largely prescribed in COLD patients whose (stable) PaO2 less than or equal to 55 mmHg. The pulmonary haemodynamic effects of OT are still a matter of debate. The first studies, in 1967, indicated that continuous O2 for 6-8 weeks could markedly improve pulmonary hypertension (PH). In the MRC study there was no change in pulmonary artery mean pressure (PAP) in patients receiving O2 for more than 15 h/day, whereas patients not receiving O2 exhibited a progressive increase of PH. In the NOTT study there was a modest but significant improvement of PAP after 6 months in those patients receiving "continuous OT" (in fact greater than 18 h/day), but not in patients receiving only nocturnal OT. In our own study, we found that OT could reverse the progression of PH in COLD patients. In 16 carefully studied patients, PAP increased from 23.3 +/- 6.8 to 28.0 +/- 7.4 mmHg (p less than 0.01) before the initiation of OT (mean duration of follow-up = 48 months) and then decreased to 23.9 +/- 6.6 mmHg (p less than 0.05) during OT (mean duration of follow-up = 31 months). The average yearly change in PAP was +1.5 mmHg before OT, and -2.1 mmHg under OT and the difference was highly significant (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamics↗
PubMed1988

Daytime pulmonary hypertension in patients with obstructive sleep apnea syndrome.

The frequency of daytime pulmonary hypertension (PH) in patients with obstructive sleep apnea syndrome (OSAS) has not been well established and its mechanisms are still under debate. We have thus performed right heart catheterization, in addition to standard spirography and arterial blood gas measurements, in a series of 46 consecutive patients in whom OSAS was firmly diagnosed by whole-night polysomnography. Only 9 of the 46 patients (20%) had PH defined by a mean resting pulmonary arterial pressure (Ppa) greater than or equal to 20 mm Hg. Among the patients without resting PH, 14 had exercising PH (defined by a Ppa greater than 30 mm Hg during 40-watt, steady-state exercise). Patients with resting PH differed from the others by a lower daytime PaO2 (60.8 +/- 7.6 versus 76.2 +/- 9.4 mm Hg; p less than 0.001), a higher daytime PaCO2 (44.6 +/- 4.2 versus 38.0 +/- 4.0 mm Hg; p less than 0.001), and lower VC and FEV1 (p less than 0.001). There was no difference between the 2 groups with regard to apnea index (62 +/- 34 versus 65 +/- 40) or the lowest sleep SaO2 (59 +/- 21 versus 66 +/- 18%) or the time spent in apnea. For the group as a whole, there was a good correlation between Ppa and daytime PaO2 (r = -0.61; p less than 0.001), PaCO2 (r = 0.55; p less than 0.001), and FEV1 (r = -0.52; p less than 0.001), but there was no significant correlation between Ppa and the apnea index, the lowest sleep SaO2, or the time spent in apnea.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Assessment of thoracic gas volume by low-frequency ambient pressure changes in children.

The validity of a new method for measuring thoracic gas volume (TGV) was studied in 69 children, 4-16 yrs old, including twelve normal children and 57 children with an obstructive (n = 38) or restrictive (n = 19) respiratory disease. The method consisted of applying very slow (0.05 Hz) sinusoidal variations of ambient pressure around the body (delta Pam = 40 cmH2O peak to peak) and studying the relationship between delta Pam and the resulting gas displacement at the mouth (Vaw): TGVapc = PB.delta Vaw/delta Pam.cos phi, where PB is barometric minus alveolar water vapour pressure and phi the phase angle between Pam and Vaw. Functional residual capacities derived from TGVapc (FRCapc) were compared to the values obtained by plethysmography (FRCplet) and by helium dilution (FRCdil). FRCapc did not differ significantly from FRCplet in either the entire group (1.75 +/- 0.62 l vs 1.79 +/- 0.45 l) or in the patient subgroups. However, with the new method a trend to slightly lower FRCs was seen in patients with the most obstruction (p less than 0.05). FRCdil was significantly lower than both FRCapc and FRCplet (p less than 0.001), particularly in children with obstruction. Significant correlations were found between the three methods (p less than 0.001). On the other hand, the method investigated requires that the subject breathe very regularly for a period of several minutes. This was rarely achieved, so that the reproducibility of the measurements was unacceptably low. At present, the method cannot be recommended for routine use in 4-16 yr old children.

Adolescent↗
PubMed1985

The day hospital as entry point to a network of long-term services: a program evaluation.

One hundred twenty-six admissions to a time-limited day hospital program were studied to obtain evaluative and descriptive information about the program and its patients. Patients most likely to complete the program were older, lived with their families, had intermediate amounts of prior inpatient admissions, and had no arrest record. Among all study patients admitted to the day hospital (dropouts as well as graduates), 62 percent were still participating in at least one long-term treatment and rehabilitation program of the parent community mental health service six months after they left the day hospital. This high retention rate appears to result from the day hospital's focus as the entry point to a large and flexible network of long-term services in the same location and with familiar staff.

Adult↗