Effect of natural oxygen enrichment at low altitude on oxygen-dependent patients with end-stage lung disease

Comparison between the 6-minute walk tests performed in patients with chronic obstructive pulmonary disease at different altitudes

Objective

To evaluate the influence of the altitude on the 6-minute walking test in patients with moderate to severe pulmonary disease.

Methods

Twenty-nine patients performed the 6-minute walk test at a pulmonary rehabilitation clinic in Santo André (above sea level), in São Paulo State, and at the Enseada Beach, in Guarujá (at sea level), also in São Paulo State. Of these 29 patients, 8 did the test both on hard sand and on asphalt to analyze if there were differences in performance during the tests. Data such as heart rate, oxygen saturation, test distance, and Borg scale were compared.

Results

We found no statistical difference in relation to oxygen saturation at rest before the beginning of the walking test in Santo André 94.67±2.26% and at sea level 95.56±2% (p=0.71). The minimum saturation measured during the test was 87.27±6.54% in Santo André and 89.10±5.41% in Guarujá (p=0.098). There were no differences in the performed distance between the different kinds of terrains; the distance on sand was 387.75±5.02m and on asphalt it was 375.00±6.54m (p=0.654). Regarding oxygen saturation during walking, the pulse oximetry on sand was 95.12±1.80% and on asphalt it was 96.87±1.64% (p=1.05).

Conclusion

Altitude did not affect the performance of the walking test in patients with moderate to severe pulmonary disease and the results were similar in both cases, on sand and on asphalt.

Inpatient paediatric rehabilitation in chronic respiratory disorders

Inpatient pulmonary rehabilitation programs have evolved from tuberculosis sanatoriums to modern medical centres providing standardized comprehensive care in a multidiciplinatory environment. Goals of rehabilitation programs for children and adolescents include restoration of professional activity, improvement of health condition, compliance and disease management as well as restoration of quality of life. Eligibility for an intervention is assessed by defined social and medical criteria. Comprehensive pulmonary rehabilitation programs provide a wide range of health care recourses, including diagnostic procedures, specific medical care, educational interventions and a multiprofessional team. Paediatric rehabilitation programs for chronic respiratory diseases, such as asthma or cystic fibrosis, have been shown to reduce symptoms, increase aerobic fitness and physical strength, improve pulmonary function and inflammation and enhance compliance, self-management, quality of life and psychological symptoms. Regional climatic effects have demonstrated an additional positive effect on the rehabilitation outcome. In addition, first evidence suggests an overall reduction of health care costs.

Effect of low altitude at the Dead Sea on exercise capacity and cardiopulmonary response to exercise in cystic fibrosis patients with moderate to severe lung disease

Oxygen supplementation may improve exercise tolerance and the physiological response to exercise in cystic fibrosis (CF) patients. Elevated barometric pressure at low altitude is a simple means of increasing the quantity of inspired oxygen. Our objectives were to examine the effect of natural oxygen enrichment (at the Dead Sea, 396 m below sea level) on exercise capacity, and the physiological responses to maximal and submaximal exercise in CF patients. Patients were tested twice: at sea level (barometric pressure, 754 +/- 6 mmHg, mean +/- SD), and at the Dead Sea (barometric pressure, 791 +/- 3 mmHg), in a randomized crossover design. We studied 14 CF patients (6 females, 8 males), aged 15-45 years, with moderate to severe lung disease (mean forced expired volume in 1 sec = 50.0 +/- 11.2% predicted). Tests at each site included resting spirometry, anthropometry, a graded submaximal exercise test, a maximal exercise test on a treadmill, and a 6-min walk test. Tests were performed in identical order at both sites. Tests at the Dead Sea were performed 72 hr after arrival. No differences between sites were observed in lung function at rest. Peak oxygen consumption was significantly improved at the Dead Sea compared with sea level (1.68 +/- 0.73 vs. 1.57 +/- 0.74 l/min, respectively, P = 0.05), along with an improvement in the ventilatory equivalent for oxygen (41.2 +/- 6.3 vs. 46.1 +/- 7.1, respectively, P < 0.05). During submaximal exercise, blood oxygen saturation improved at the Dead Sea compared with sea level at all exercise intensities (P < 0.05). In conclusion, these results suggest that even a brief stay at the Dead Sea area may have physiological benefits for CF patients with moderate to severe lung disease.

Assessing health status and quality of life in idiopathic pulmonary fibrosis: which measure should be used?

Many studies conducted on the health status and quality of life (QOL) of patients with certain chronic diseases have demonstrated that their disease had an impact on their lives. However, less is known about the QOL and health status of patients suffering from idiopathic pulmonary fibrosis (IPF). In the present study, three focus groups of IPF patients (n=10) were run to identify the aspects of QOL or health status that are relevant to this population and to establish which measure is preferable to assess these aspects. The patients completed and discussed the St. George's Respiratory Questionnaire (SGRQ) and the World Health Organization Quality of Life assessment instrument (WHOQOL-100). Results indicated that hobbies/leisure activities, mobility, transport, social relationships, working capacity, energy and doing things slower were aspects relevant to IPF patients' QOL. The WHOQOL-100, with an additional social support questionnaire, appeared to be preferable.

[High prevalence of long-term domiciliary oxygen therapy with a low percentage of inappropriate prescription in the Madrid health care area. Evaluation of the correct use]

The efficacy of long-term domiciliary oxygen therapy (DOT) has been confirmed in patients who comply with guidelines; however, the prevalence in different populations varies greatly although no satisfactory explanation has been found for this.

OBJECTIVES

To assess the prevalence of inappropriate use of DOT in the health care area of the Community of Madrid, where demographic and health care features are well-defined.

MATERIAL AND METHODS

Descriptive, transversal population study enrolling all patients with DOT in our health care area over a period of one year (May 1995 to Mayo 1995). Inappropriate use was defined as characterized by at least one of the following conditions: inappropriate prescription, poor compliance or continued smoking.

RESULTS

The total number of patients was 860, the prevalence of DOT use being 178.3 per 100,000 inhabitants for the period. Ninety-three refused to participate. Nearly half the patients ha been using oxygen therapy for over two years. Seventy percent were followed by pneumologists. Seventy-four percent were men, with a mean age of 70 +/- 9 yr. Criteria for prescription were not followed in 9.7% of the cases. Chronic obstructive pulmonary disease was the reason for prescribing DOT in 59.7%. Use was appropriate in 719 cases. Use was inappropriate in 337 (46.9%), related to poor compliance in 60.5%, current smoking in 11%, and inappropriate prescription in 5.6% and for more than one criterion in 22.8%.

CONCLUSIONS

The prevalence of DOT use in our health care area is very high. The percentage of inappropriate use is high, although similar to that of other populations, and highly related to poor compliance. The percentage of inappropriate prescription is low. Possible reasons for the high prevalence are discussed.

Effects of low altitude on exercise performance in patients with congestive heart failure after healing of acute myocardial infarction

Patients with chronic congestive heart failure (CHF) have impaired oxygen delivery to working muscles. The Dead Sea, the lowest site on earth, is distinguished by natural oxygen enrichment, low humidity, high barometric pressure, and temperature with increased bromide and magnesium concentrations in the inspired air. The aim of this study is to examine the effects of descent to the Dead Sea on patients with CHF. Twelve patients with CHF and 4 age-matched healthy controls underwent complete echocardiographic studies at rest as well as treadmill and metabolic stress tests, both in Haifa, 130 m above sea level and 3 days after descent to the Dead Sea, 402 m below sea level. Significant changes in parameters at the Dead Sea compared with Haifa included time on treadmill, which increased from 612+/-198 to 672+/-1 86 seconds (p <0.05); the Borg scale decreased by 1 to 2 grades (p <0.05); and oxygen saturation increased by 3% throughout exercise (p <0.05). Systolic blood pressure decreased by 9 mm Hg at rest (p <0.05) and increased by 14 mm Hg at peak exercise at the Dead Sea in patients with CHF (p <0.05). Cardiac output at rest increased by 300 ml/min (p <0.05). Maximum oxygen consumption (VO2max) increased by 126 ml/ min (p <0.05), and even more so in patients with more severe exercise-induced oxygen desaturations, which was associated with lower peak minute ventilation to CO2 production ratio (p <0.05). Thus, descent to the Dead Sea acutely improved exercise performance due to better oxygenation and loading conditions in patients with CHF.

Effect of low altitude (Dead Sea location) on exercise performance and wall motion in patients with coronary artery disease

To evaluate the effects of low altitude on exercise performance and myocardial ischemia, 12 patients with coronary artery disease and 6 normal controls underwent ergometric and exercise echocardiography in Haifa, 130 m above sea level, and at the Dead Sea, 402 m below sea level. At the Dead Sea, exercise duration increased by 15% (p <0.05) in the patient and control groups and wall motion score index was improved in patients at rest and after exercise, indicating that descent to the Dead Sea in patients with coronary disease is safe, improves exercise performance, and decreases ischemia.

Rehabilitation of hypoxemic patients with COPD at low altitude at the Dead Sea, the lowest place on earth

BACKGROUND

In patients with COPD, oxygen therapy has been shown to improve exercise capacity and survival. Increase in barometric pressure at low altitude can serve as a simple way to improve arterial oxygenation in hypoxemic patients. We have tried to evaluate the effect of staying at low altitude on arterial oxygenation and exercise performance in patients with COPD.

PATIENTS AND METHOD

Eleven patients with COPD (9 male, 2 female) aged 38 to 79 years (mean FEV1, 0.96 L; 36% predicted) with hypoxemia (mean PaO2, 54.2+/-8.9 mm Hg) at Jerusalem (altitude 800 m above sea level) were taken down to the Dead Sea area (altitude 402 m below sea level) for 3 weeks. At both locations we tested arterial blood gases, spirometry, progressive exercise, 6-minute walking distance, and sleep oximetry. The study was repeated 2 weeks after returning to Jerusalem.

RESULTS

Spirometry results were unchanged. Mean arterial PaO2 rose from 54.2+/-8.9 mm Hg to 69.5+/-11 at the first week and to 66.6+/-11 at the third week of stay (p<0.001). PaCO2 rose from 43.5+/-9.8 mm Hg to 47.7+/-9 and 49.5+/-8.4 (p<0.006). Six-minute walking distance rose from 337+/-107 m to 449+/-73 and 507+/-91 in the third week (p<0.005). Maximum oxygen consumption (VO2max) rose from 901+/-257 mL/min to 1,099+/-255 and 1,063+/-250 mL/min (p=0.01). Sleep oximetry showed an increase in mean sleep arterial oxygen saturation from 86.0+/-4.3% to 89.9+/-4.2% and 88.3+/-3.0 at 1 and 3 weeks, respectively (p<0.05). Following the return to Jerusalem, arterial gases returned to their baseline levels (PaO2, 52.9+/-9.4 mm Hg) but 6-min walking distance remained significantly high, 453+/-47 (p<0.02), and VO2max remained high as well (1,102+/-357 mL/min), although it did not reach statistical significance.

CONCLUSIONS

Decline to low altitude or staving at high oxygen environment improves arterial oxygenation and exercise capacity in hypoxemic patients residing in moderate or high altitude. Low altitude (or pressurized wards) can improve pulmonary rehabilitation of hypoxemic patients with COPD.