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O Okada

Publications and source records attributed to O Okada.

At least 37 records · Page 2Linked to original sources

Lipodermatosclerosis - report of three cases and review of the literature.

We report 3 cases of lipodermatosclerosis (LDS) and discuss the nosology of similar disorders caused by venous insufficiency of the legs. These cases are characterized by (1) occurrence in middle-aged or aged woman, (2) painful, indurated erythema with hyperpigmented scleroderma-like hardening on the lower leg, (3) lobular panniculitis with membranocystic fat necrosis and various degrees of septal fibrosis. Although the designation LDS has been used particularly in the UK and in the USA, this entity is not familiar in other countries including Japan. LDS clinically represents a wide spectrum from an acute, inflammatory phase to a chronic, fibrotic state. The clinicopathologic findings of LDS are similar or identical to the disease previously reported as chronic indurated cellulitis, hypodermitis sclerodermiformis, stasis panniculitis or sclerosing panniculitis. These diseases are probably related conditions, which depend upon the various stages.

Aged↗

Prediction of life expectancy in patients with primary pulmonary hypertension. A retrospective nationwide survey from 1980-1990.

Primary pulmonary hypertension (PPH) is a progressive disease of unknown etiology usually followed by death within 5 years after diagnosis. Although heart-lung or lung transplantation is now offered to patients with advanced PPH, adequate criteria assessing an accurate prediction of life expectancy in PPH has been difficult to establish. The aims of this study were to identify the characteristic features associated with a poor prognosis in patients with PPH, and to attempt to establish an individual prognostic index that predicts with great accuracy survival or death of PPH after one year, thereby helping to define criteria for patient selection for transplantation. In 1991, a retrospective nation-wide survey on PPH was conducted in Japan, and the clinical and cardiorespiratory variables of 223 PPH cases (female; 144, male; 79) in the period from 1980-1990 were obtained. The mean pulmonary arterial pressure (PPA) was 57.5+/-17.2 mm Hg (mean+/-SD), and the overall median survival time was 32.5 months since the first diagnostic catheterization. The characteristic features of 61 patients who died within one year of catheterization (Nonsurvivors group) were compared to 141 patients who survived one year or more from the time of catheterization (Survivors group). Among several clinical and cardiorespiratory variables, heart rate, PPA, right atrial pressure (PRA), stroke volume index (SI), pulmonary vascular resistance, and partial pressure of carbon dioxide (PaCO2) were significantly different between the two groups. As the independent factors, PPA, PRA, SI, and PaCO2 were selected for the multiple logistic analysis. Using a 0.7 probability cut-point to separate Nonsurvivors from Survivors, 84.6% of Nonsurvivors and Survivors could be correctly predicted from this logistic regression equation. Predictive equations like the present preliminary one can be used in the future to better assess life expectancy in patients with PPH in whom transplantation will be considered.

Adolescent↗

[Investigation of pulmonary hemodynamics and chest X-ray findings in patients with pulmonary tuberculosis sequelae and obstructive ventilatory impairment].

We investigated pulmonary hemodynamics and chest X-ray findings to explore significance of obstructive ventilatory impairment in patients with pulmonary tuberculosis sequelae. One hundred and two patients underwent examinations of blood gases, spirometry, and right cardiac catheterization. The patients were divided into two groups, according to forced expiratory volume in one second as the percentage of forced vital capacity (FVC), which was expressed as FEV1%. Group A (n = 38) had FEV1% of 55% or lower and Group B (n = 64), FEV1% above 55%. First, the values of blood gases and hemodynamics were compared between the two groups, regarding the percent predicted value of FVC as a covariate. Secondly, between 26 of Group A and 42 of Group B, the change of pulmonary arteriolar resistance (PAR) before and after 100% oxygen breathing for 10 minutes was compared. These comparisons were made by exploratory data analysis. Lastly, we described every case with five items of chest X-ray findings and the extent of each finding we had defined. The items were emphysematous change; fibrosis, bronchiectasis and/or cavity; pulmonary resection and/or atelectasis; pleural thickening; and thoracoplasty. We explored X-ray findings influenced on airway obstruction by ridit (abbreviation for "relative to an identified distribution") analysis, taking smoking status into consideration. The results were as follows. (1) The patients of Group A tended to show severer hypoxemia and tissue hypoxia than the patients of Group B. (2) The patients of Group A tended to show worse values of pulmonary hemodynamics than the patients of Group B. Under an even level of the arterial oxygen tension that was 60 Torr or lower, pulmonary artery mean pressure was higher in Group A than in Group B. (3) PAR after oxygen breathing was less likely to decrease in Group A than in Group B. (4) As any mean ridit was standardized and adjusted to 0.5 in Group B, every mean ridit of "emphysematous change" in Group A was the largest-0.63 in non-smokers, 0.74 in ex-smokers and 0.70 in current smokers. Therefore, "emphysematous change" was more influenced on airway obstruction than any other finding because of the largest mean ridit. We conclude as follows. Pulmonary hypertension is more serious in patients suffering from severe airway obstruction with pulmonary tuberculosis sequelae, and it may be attributable to reduction in capacity of anatomical pulmonary vascular bed rather than hypoxic pulmonary vasoconstriction. Pathological changes such as "emphysematous change" on the radiograph might be considered as an important cause of obstructive ventilatory impairment.

Adolescent↗

[Pulmonary hemodynamic and gas exchange effects of various oxygen concentrations in patients with severe pulmonary hypertension primarily affecting the pulmonary vasculature].

The aim of this study was to evaluate pulmonary hemodynamic and gas exchange response to oxygen inhalation in patients with severe pulmonary hypertension primarily affecting the pulmonary vasculature. This study included 7 patients with primary pulmonary hypertension (PPH), 11 with pulmonary hypertension related to collagen vascular diseases (CoPH), and 18 with chronic thromboembolic pulmonary hypertension (CTEPH). All patients had mean pulmonary arterial pressure (PPAm) of greater than 25 mm Hg. We divided the patients into two groups: a PPH + CoPH group comprising the 7 PPH and 11 CoPH patients, and the CTEPH group. We measured cardiopulmonary variables after 10 min inhalation of various oxygen concentrations (FiO2 0.24, 0.28, 0.4, 1.0). In the PPH + CoPH group, PPAm significantly decreased after the inhalation of oxygen concentrations of 40% or more. This was associated with a significant reduction in pulmonary arteriolar resistance (PAR), and suggested active pulmonary vasodilation was caused by oxygen inhalation. In the CTEPH group, on the other hand, PPAm significantly decreased after the inhalation of oxygen concentrations of 28% or more, apparently in association with a significant fall of cardiac output. However, PAR was unchanged regardless of the inspired oxygen concentration, indicating an absence of pulmonary vasodilation in the CTEPH group. When breathing room air, 7 patients in the PPH + CoPH group (38.9%) and 10 in the CTEPH group (55.6%) demonstrated mixed venous oxygen tension (PvO2) values of less than 35 Torr. Extra attention should be paid to PvO2 when administering oxygen therapy to patients with severe pulmonary hypertension.

Collagen Diseases↗

[Investigation of pulmonary hemodynamics and chest X-ray findings in hypercapnic patients with pulmonary tuberculosis sequelae].

We investigated pulmonary hemodynamics and chest X-ray findings to explore pathophysiological significance of chronic hypercapnia in patients with pulmonary tuberculosis sequelae. One hundred and seven patients underwent examinations of blood gases and right cardiac catheterization. The patients were divided into two groups, according to arterial carbon dioxide tension under room air breathing (PaCO2). Group I (n = 35) was defined as 45 Torr or lower of PaCO2, and Group II (n = 72) was the hypercapnic group whose PaCO2 was over 45 Torr. In addition, spirometry was done in 34 patients of Group I and 68 of Group II. First, the values of blood gases, spirometry and pulmonary hemodynamics were compared between the two groups. Secondly, between 22 of Group I and 50 of Group II, the values of pulmonary arteriolar resistance (PAR) before and after 100% oxygen breathing for 10 minutes were compared. These comparisons were made by exploratory data analysis. Lastly, we described in all cases with five items of chest X-ray findings and the extent of each finding we had defined. The items were emphysematous change; fibrosis, bronchiectasis, and/or cavity (hereafter abbreviated as "fibrosis"); lung resection and/or atelectasis; pleural thickening; and thoracoplasty. We explored the items of X-ray findings which may relate to hypercapnia by ridit (abbreviation for "relative to an identified distribution") analysis. The results were as follows. (1) Hypercapnic patients tended to have severer restrictive ventilatory impairment and hypoxemia. Under an even level of arterial oxygen tension (PaO2), tissue oxygenation was not poorer in Group II than in Group I. (2) Hypercapnic patients tended to have more unfavorable pulmonary hemodynamics. More than half of them had pulmonary hypertension defined as 20 mmHg or higher of pulmonary artery mean pressure (PAm). Under an even level of PaO2, PAm was higher in Group II. Although 34 patients of Group II showed PaO2 over 60 Torr, 23 of them had pulmonary hypertension. (3) PAR after oxygen breathing was more likely to decrease in Group II than in Group I. (4) As any mean ridit was standardized and adjusted to 0.5 in Group I, the maximum was the mean ridit of "pleural thickening" (= 0.67), next "fibrosis" (= 0.65) in Group II. The above two items of X-ray findings, in which each mean ridit was higher than in any other item, were more influential on hypercapnia. We conclude as follows. (1) Pulmonary hypertension is severer in hypercapnic patients with pulmonary tuberculosis sequelae; it may be mainly attributable to hypoxic pulmonary vasoconstriction. (2) An important cause of chronic hypercapnia may be pathological changes such as "pleural thickening" and "fibrosis" seen on the radiogram.

Adult↗

[A case of preoperatively diagnosed primary pulmonary leiomyosarcoma].

A 29-year-old woman had been suffering from right back pain for 3 months. Chronic pulmonary thromboembolism was suspected and she was referred to our hospital. She presented with no risk factors for thromboembolism, and during the previous 6 months had lost 4 kg in body weight. Chest radiography showed nodular shadows in the lower field of the right lung. Contrast-enhanced computed tomography demonstrated a filling defect in the right pulmonary artery and nodular lesions in the lower field of the right lung, which were considered to be signs of pulmonary infarction. Absence of perfusion into the right lung was demonstrated by a perfusion scan. Right heart catheterization showed normal pressure in the pulmonary arteries, and pulmonary angiography showed an abrupt cutoff of the right pulmonary artery, which was similar to the finding of pulmonary thromboembolism. A transvenous catheter suction biopsy was performed in the right pulmonary artery and the histopathologic findings yielded a diagnosis of leiomyosarcoma. The patient underwent surgical resection under total cardiopulmonary bypass. A large tumor completely filled the right main pulmonary artery and invaded the posterior wall of the pulmonary trunk close to the left main pulmonary artery. Primary pulmonary leiomyosarcoma is a rare tumor and its prognosis is very poor. Radical surgical resection is the only effective treatment, but early diagnosis is very difficult. Transvenous catheter suction biopsy is a useful procedure for the early diagnosis of pulmonary artery sarcoma.

Adult↗

[Prognosis and management in patients with left main shock syndrome--emergency PTCA following CABG].

To clarify the optimal management and delineate the characteristics of patients with severe left main disease and cardiogenic shock as a result of an acute anterolateral myocardial infarction (left main shock syndrome), we analyzed the course of 13 such patients from September 1989 to June 1997. Of the 13 patients, 7 (53.8%) were managed with emergency coronary angioplasty (group A), 3 (23.1%) were treated with emergency coronary angioplsty following coronary bypass graft surgery (group B) and 3 (23.1%) underwent emergency coronary bypass graft surgery alone (group C). The interval from the beginning of myocardial ischemia to revascularization was 266 +/- 303 min. The degree of diameter stenosis found in the left main coronary artery was 98.1 +/- 1.8%. Overall in-hospital mortality for the 13 patient with left main shock syndrome was 76.9% (group A: 7/7; group B: 1/3; group C: 2/3, NS) and operative mortality was 61.5% (group A: 6/7; group B: 0/3; group C: 2/3, p = 0.03). When all 13 patients were examined together, the presence of ventricular tachycardia (VT) x ventricular fibrillation (Vf) was found to be the most powerful univariate predictor of operative death (p = 0.03). This is, 7 (87.5%) of the 8 patients with VT x Vf at presentation died within 30 postoperative days, and only 1 (20%) of the 5 patients without VT x Vf died (p = 0.03). Age, percent stenosis of the left main or right coronary arteries, the interval from the beginning of myocardial ischemia to revascularization, intubation, systolic pressure, fractional shortning, pulmonary artery pressure, pulmonary capillary wedge pressure, coronary risk factors, pulmonary edema, mitral regurgitation and percutaneous cardiopulmonary support failed to attain univariate significance at the P = .1 level. The postoperative peak CPK level was 15665 +/- 6710 IU/1 in operative death compared to 4733 +/- 2749 IU/1 in operative survival (p = 0.01). In conclusion, emergency coronary angioplasty following coronary bypass graft surgery for left main shock syndrome has been a very successful therapeutic option. Finally, for the entire group of 13 patients with left main shock syndrome, VT x Vf significantly decreased short-term survival.

Adult↗

Arterial and mixed venous oxygen desaturation during incremental exercise in patients with chronic pulmonary disease.

We evaluated arterial and mixed venous oxygen desaturation during symptom-limited exercise in patients with chronic pulmonary disease. Patients were divided into five groups according to disease: [chronic pulmonary emphysema (CPE), chronic bronchitis (CB), pulmonary tuberculosis sequalae (TB-seq), fibrosing lung disease (FLD), and pulmonary vascular disease (PVD)]. There were no significant difference in the values of arterial (PaO2) and mixed venous (PvO2) oxygen tension before and at the end of exercise among the five groups, whereas absolute decreases in PvO2 were significantly larger in PVD and FLD. The changes in PvO2 were similar to the changes in the coefficient of oxygen delivery (COD) which is equal to oxygen transport divided by oxygen consumption. These results suggest that the relative decrease in oxygen transport during exercise due to the high ratio of oxygen extraction by tissues is an important factor to determine decreases in PvO2 in pulmonary hypertensive disease and fibrosing lung disease.

Aged↗

[An aged patient with stage IV ovarian cancer successfully treated by intraperitoneal consecutive administration of cisplatin].

The patient was an aged woman with ovarian cancer stage IV that was classified as serous papillary adenocarcinoma. The primary lesion, 60 x 70 x 100 mm in size, was detected in the left ovary and the lymph node metastasis, 54 x 35 mm in the maximum size, expanded from the pelvic lymph node to the left supraclavicular lymph node. The patient underwent three courses of chemotherapy at intervals of three weeks. Cisplatin was intraperitoneally administered in a divided dose of 20 mg from day 1 to day 4, and cyclophosphamide was intravenously infused in a dose of 500 mg on day 1. As a result, histological efficacies of Grade III were recognized not only in the primary lesion but also in the metastatic lesions including lymph nodes. No adverse effects were observed, and the free Pt AUC in cubital blood measured after a course of chemotherapy (3.0 mg.hr/l) was higher than that measured after 2 hour-drip infusion of cisplatin 100 mg/day. The concentration of free Pt in ascites measured one hour after intraperitoneal administration was 2.8 micrograms/ml. These findings show that this method is a highly effective therapy with few adverse effects. In view of these advantages, this therapeutic technique should be considered as first-line chemotherapy for aged patients and those with serous adenocarcinoma who prefer in-home treatment.

Aged↗

Computer determination of perfusion patterns in pulmonary capillary networks.

Individual pulmonary capillaries are not steadily perfused. By using in vivo microscopy, it can readily be demonstrated that perfusion continually switches between capillary segments and between portions of the network within a single alveolar wall. These changes in capillary perfusion occur even when upstream pressure and flow are constant. Flow switching between capillary segments in the absence of hemodynamic changes in large upstream vessels suggests that capillary perfusion patterns could be random. To calculate the probability that perfusion patterns could occur by chance, it is necessary to know the total number of possible perfusion patterns in a given capillary network. We developed a computer program that can determine every possible perfusion pattern for any given capillary network, and from that information we can calculate whether perfusion of individual segments in the network is random. With the results of the computer program, we have obtained statistical evidence that some capillary segments in a network are nonrandomly perfused.

Animals↗

The efficacy of pulmonary thromboendarterectomy on long-term gas exchange.

It has not been delineated in detail how pulmonary thromboendarterectomy (PTE) affects gas exchange through long-term follow-up. In Japan, this surgery has been undertaken in a limited number of institutions, and the results of PTE have not been well publicized. A total of 25 patients were operated on during the period from 1985 to 1996 at our institution, and the overall mortality rate was 16%. Our criteria for PTE were based on the following: 1) thrombi surgically accessible as judged by angiographic study; 2) mean pulmonary arterial pressure > or = 30 mmHg. The efficacies of PTE were analysed on haemodynamics as well as gas exchange at one month postsurgery and during follow-up (6-24 months). Significant haemodynamic improvement was obtained as early as 1 month after surgery. Improvement of gas exchange lagged, but was then observed during follow-up, and the improvement level of pulmonary haemodynamics was sustained. The early postoperative restrictive impairment and ventilation-perfusion abnormality on lung perfusion scan resolved during the follow-up period. It was concluded that the early postoperative efficacy of pulmonary throm-boendarterectomy was mainly achieved due to the reduction of pulmonary hypertension, whereas improvement in gas exchange was obtained over the longer term.

Adult↗

[A case of FIGO stage IV A vulvar cancer successfully treated by neoadjuvant chemotherapy with continuous intra-arterial infusion (cisplatin, 5-fluorouracil)].

The subject was a patient who had squamous cell carcinoma in the pudendum and the inguinal region (12.5 x 8.0 cm and 4.5 x 3.0 cm, respectively). A curative operation for FIGO IV A stage (T3N3M0) vulvar cancer is thought to be difficult to perform and is resistant to BOMP therapy, so continuous arterial infusion therapy consisting of cisplatin (CDDP, 10 mg/day, day 2-4, one shot) and 5-fluorouracil (5-FU, 250 mg/day, day 1-4, continuous) was performed weekly via bilateral femoral arteries to the lower end of the branches of bilateral superior gluteal arteries. In consequence, the tumor started to clearly shrink from the first week. After treatment with total doses of 210 mg of CDDP and 7,000 mg of 5-FU, the patient underwent complete resection of the tumor without skin grafting, and a histological efficacy of Grade 1-b or above was obtained. No adverse reactions were found, and the free Pt AUC in the peripheral blood was 0.85 mg.hr/l per course. Pt concentration in the pudendum 2 hours after CDDP therapy was 2.9 micrograms/g. Because of little adverse reaction and high efficacy, this method appeared to be a therapeutic method worth considering from the viewpoint of the quality of life of patients with the progressive vulvar cancer prevalent in elderly persons.

Aged↗

[Nocturnal pulmonary hypertension in patients with obstructive sleep apnea associated with daytime pulmonary hypertension].

We investigated the effect of state-specific changes associated with REM sleep on pulmonary artery pressure in patients with obstructive sleep apnea (OSAS). Six male patients with OSAS (age; 40 +/- 12 SD yrs, BMI; 39.0 +/- 8.6 kg/m2, AHI; 51.5 +/- 28.5) were examined throughout the night by polysomnography, while monitoring pulmonary artery pressure via right cardiac catheterization. All patients had pulmonary hypertension (PH) during periods of wakefulness, and their mean pulmonary artery pressure (PAPm) was 31.1 +/- 7.4 mmHg. PAPm was analyzed at two different points in each apneic episode. PAPbase was the baseline value when inspiratory effects during apnea were not elicited, and PAPpeak was the peak value observed just after the cessation of OSA. PAPpeak was higher in REM (56.3 +/- 12.4) than in NREM (41.4 +/- 6.9 mmHg; P < 0.01), and both values were significantly higher than those observed during periods of wakefulness. The magnitude of elevation of PAP (delta PAP; PAPpeak-PAPbase) in REM and NREM were 11.6 +/- 2.0 and 6.9 +/- 2.8 mmHg, respectively. Relative ratios in the response of PAP to a decrease in O2 desaturation (delta PAP/delta SpO2) showed almost the same value for REM (-0.57 +/- 0.27) and NREM sleep (-0.57 +/- 0.26 mmHg/%). The values of PAPm at SpO2 75% were significantly higher in REM than in NREM (48.7 +/- 11.2 vs. 41.6 +/- 6.2 mmHg). We conclude that transient pulmonary hypertension could be caused not only by hypoxia, but also by state-specific responses (which are unrelated to hypoxia) that occur during REM sleep.

Adult↗

Successful utilization of the median sternotomy approach in the management of descending necrotizing mediastinitis: report of a case.

We describe herein the case of a patient in whom a median sternotomy was successfully employed for mediastinal drainage in the treatment of descending necrotizing mediastinitis (DNM). Although most reports describe cervical or thoracotomy approaches, our experience strongly suggests that median sternotomy is a satisfactory alternative approach for treatment of this disease.

Adult↗

[Three cases of uterine cervical adenocarcinoma successfully treated by neoadjuvant chemotherapy with continuous intra-arterial infusion (cisplatin, 5-fluorouracil)].

Low-dose consecutive intra-arterial infusion therapy with cisplatin and 5-fluorouracil as neoadjuvant chemotherapy was performed on 3 cases of cervical adenocarcinoma (two stage IIb and one stage IIIb). Ten-day infusion of cisplatin 10 mg/day (one shot) and 5-fluorouracil 250 mg/day (continuous) into blood flow-altered bilateral internal iliac arteries, was carried out as one course and 2 times at intervals of 3 weeks. As a result, side effects were slight, and all of these 3 cases showed a tumor diminution rate of above 83.5%, making it possible to perform complete tumorectomy through radical hysterectomy. However, some postoperative additional treatment was thought to be necessary, considering that with the present method, the area under the curve of free Pt of cubital venous blood is 2.4 mg hr/l and that by the present method alone long-term survival cannot be expected in cervical adenocarcinoma.

Adenocarcinoma↗

[Relation of pulmonary hemodynamics and ventilation to tissue hypoxia during exercise in patients with tuberculosis sequelae].

We examined a relationship between tissue hypoxia and pulmonary hemodynamics or ventilatory capacity during rest and exercise in patients with tuberculosis sequelae. Nine patients performed exercise test until their symptom limit. Mean pulmonary arterial pressure (PPA) during exercise was plotted against cardiac index (C.I.) from rest to maximum exercise in each patient. In most of the patients, the changes of PPA showed linear relation with the C.I., and a slope (P-F slope) was obtained from the regression equation in each patient, and it was used as an index of circulatory disability during exercise. At the same time a coefficient of oxygen delivery (COD) was calculated and mixed venous oxygen tension (PvO2) was measured to evaluate a tissue hypoxia at rest and during exercise. The changes of COD were similar to those of PvO2 during exercise. COD positively correlated with PvO2 (R = 0.873, P < 0.01) from rest to maximal exercise, indicating that the values of PvO2 depended on those of COD. P-F slope negatively correlated with S.I. (R = -0.887, P < 0.01), oxygen transport (R = -0.780, P < 0.01), COD (R = -0.827, P < 0.01) and PvO2 (R = -0.760, P < 0.01) at maximal exercise. Whereas no significant relationship between ventilatory variables and COD or PvO2 was noted at maximal exercise. In conclusion, the patients with pulmonary tuberculosis sequelae who had a step P-F slope showed low mixed venous oxygen tension during exercise as a result of limited oxygen transport in consequence of low stroke volume.

Cell Hypoxia↗

[Compliance with long-term home oxygen therapy].

Long-term home oxygen therapy has been shown to benefit patients with hypoxemic chronic obstructive pulmonary disease. However, to obtain the expected maximal benefit it is important for the oxygen to be used correctly and for a sufficient length of time. We examined compliance with home oxygen therapy in patients with chronic obstructive pulmonary disease, pulmonary fibrosis, late sequelae of pulmonary tuberculosis, and pulmonary hypertension who used oxygen concentrations. Compliance was defined as the ratio of the amount of oxygen used to the amount prescribed. The average daily length of time the concentrator actually ran was measured from the concentrator meters. These were read every 6 months by an engineer from the company that installed the concentrator. Factors thought to affect compliance were studied. These factors included age, the degree of dyspnea, arterial blood gases, and pulmonary function. Weak positive correlations were found between compliance and age and between compliance and PaCO2. A weak negative correlation was observed between compliance and PaO2. Compliance in patients with chronic obstructive pulmonary disease was higher than in patients with pulmonary fibrosis or pulmonary hypertension. Among those given prescriptions for 24-hr oxygen therapy, compliant patients had more severe dyspnea on excertion than did noncompliant patients. These data suggest that the compliant patients had more severe gas exchange problems.

Aged↗

[Prognostic value of acute pulmonary vascular response to oxygen inhalation in patients with chronic obstructive pulmonary disease].

Seventy-two patients with chronic obstructive pulmonary disease (COPD) underwent right heart catheterization when they were clinically stable and the relationship between length of survival and acute pulmonary vascular response to 100% oxygen inhalation was studied. Oxygen inhalation significantly reduced mean pulmonary arterial pressure (PPA), cardiac index (CI), and pulmonary arteriolar resistance (PAR). The percent change in PAR (% delta PAR) was used as an index of the acute pulmonary vascular response to 100% oxygen inhalation. Each patient was classified as a responder (% delta PAR > or = 15%) or a nonresponder (% delta PAR < 15%). The cumulative survival rates of these two groups were compared. Responders survived significantly longer than did nonresponders (mean survival times were 2571 days and 1432 days, respectively). The two groups did not differ significantly in anthropometic data, pulmonary hemodynamics, or blood gas data measured at base line during air inhalation. However, FEV1 and VC were significantly lower in nonresponders than in responders. The % delta PAR was not significantly related to age, PPA, PAR on air inhalation, FEV1, FEV1%, VC or VC%. We conclude that the pulmonary vascular response to oxygen inhalation (% delta PAR) may be an independent prognostic factor in patients with COPD.

Administration, Inhalation↗