Amyotrophic lateral sclerosis: gender differences in the use of mechanical ventilation.

BACKGROUND AND PURPOSE: Invasive and non-invasive mechanical ventilation are therapeutic options in patients with amyotrophic lateral sclerosis (ALS). Related to known national ALS incidence figures, the study aims to examine gender aspects versus physiological data in patients with ALS commencing mechanical ventilation. METHODS: ata from two nationwide registers involving all patients with ALS in Norway and Sweden who started invasive and non-invasive mechanical ventilation during 2002-2007. RESULTS: The total ALS population on invasive and non-invasive mechanical ventilation comprised n = 308 subjects [Norway n = 96 (72% men), Sweden n = 212 (69% men)]. Compared to Swedish ALS incidence figures, our finding of a male/female ratio of 2.3/1 in patients with ALS on invasive and non-invasive mechanical ventilation shows a statistically significant male predominance in the use of mechanical ventilation (P-value 0.0084 Chi square). Only 6.7% of men and 3.8% of women had invasive (via tracheotomy) ventilation (P = 0.344). Initiation of mechanical ventilation was acute (not planned) in 18% of patients (no gender difference). Age distribution (mean age 62), pulmonary function tests (FVC%pred, FEV(1) %pred), daytime blood gas analyses (PaO(2), PaCO(2)) and survival revealed no statistically significant gender differences. CONCLUSION: In Norwegian and Swedish patients with ALS on invasive and non-invasive mechanical ventilation, two-thirds were men. Associated with known national ALS male/female incidence figures, our finding shows that statistically significantly more men than women with ALS are using mechanical ventilation. Physiological data and survival were equal in both genders. This may indicate the need for a more aggressive approach to stimulate mechanical ventilation in female patients with ALS.

Quality of life in patients with chronic alveolar hypoventilation.

Measurements of health-related quality of life (HRQL) have not been reported in patients with chronic alveolar hypoventilation (CAH) before starting home mechanical ventilation. The purpose of this study was to investigate quality of life in a population of such patients. Forty-four consecutive patients with CAH due to previous polio, scoliosis, healed pulmonary tuberculosis or neuromuscular disease answered a battery of condition specific and generic (Sickness Impact Profile, Hospital Anxiety and Depression scale, Mood Adjective Check List) self-report questionnaires. Spirometry, arterial blood gases and overnight oxygen saturation were measured. Patients with untreated CAH had significantly impaired HRQL compared to historical data from a healthy reference population. Sleep-related problems were frequent. Age, underlying disease, and standard bicarbonate correlated significantly with HRQL measures, albeit with modest levels of explained variance (8-37%). Patients with chronic alveolar hypoventilation due to neuromuscular or restrictive chest wall disorders had severely impaired health-related quality of life. Age, the underlying disease and severity of hypoventilation are each related to the health-related quality of life decrements. Health-related quality of life measurements add important information to traditional clinical observations.

Home mechanical ventilation in Sweden, with reference to Danish experiences. Swedish Society of Chest Medicine.

The Swedish Society of Chest Medicine has started a national register of patients on home mechanical ventilation, to establish reliable national prevalence data and to accurately document patient and treatment characteristics to enable a scientific evaluation of this treatment. In this first collection of retrospective register data, covering patients on home mechanical ventilation at the register start on 1 January 1996, we found 541 patients, corresponding to 6.1/100000 inhabitants, using home mechanical ventilation. Non-invasive ventilation, night-time ventilation and volume controlled ventilation dominated. We found four diagnosis categories of approximately equal size, namely post-polio, chest wall deformities, neuromuscular diseases and 'other diseases'. The age distribution was bimodal, with one small peak in the 20-29 year group and a large peak in the 60-69 year group. A survey of Danish patients on home mechanical ventilation showed that they were considerably younger and that almost half of them suffered from neuromuscular diseases. Further work will be done to follow the situation in Sweden and in Denmark to elucidate the obvious differences in the selection of patients for home mechanical ventilation.

[Artificial respiration at home seen in a 5-year perspective. Established treatment, but remarkable differences among the counties]. / Hemrespiratorbehandling i ett femårsperspektiv. Etablerad behandling, men anmärkningsvärda skillnader mellan landstingen.

The Swedish prevalence of home mechanical ventilation is 8.2 per 100.000 with 10% annual increase. There is a large span (20 vs 2 per 100.000) between "top level" and "low level" counties, in spite of Sweden's homogeneous publicly financed system for provision of health care. The largest prevalence difference was found in patients with obstructive sleep apnoea syndrome (Pickwickian type), but their blood gas and lung function data were identical in top-level vs low-level counties. These data refute the hypothesis of overprescription in top-level counties. We conclude that the most probable explanation is under-recognition of patients in low-level counties.

Lung function and clinical outcome in postpolio patients: a prospective cohort study during 11 years.

The object of this investigation was to prospectively study the annual decline in lung function in a cohort of postpolio patients, and to determine the usefulness of initial lung function tests in the prediction of a subsequent poor outcome. Cross-sectional data were analysed in 55 patients from the total cohort of 350 survivors of poliomyelitis in our admission area of 550,000 inhabitants. Longitudinal data (> 5 yrs, average 8.9 yrs) were available for 31 patients. Seventeen of the patients had a poor outcome (13 were started on domiciliary artificial ventilation and five died from respiratory failure; with one overlap). At the time of entry to the study (on average 4.3 years before the poor outcome), these patients had a lower vital capacity (VC) (43 vs 65% of predicted; p < 0.01) and arterial oxygen tension (Pa,O2) (9.9 vs 11 kPa; p < 0.05) and a higher arterial carbon dioxide tension (Pa,CO2) (6.0 vs 5.0 kPa; p < 0.01). They also had a more rapid increase in Pa,CO2 (0.3 vs 0.03 kPa.yr-1; p < 0.01), but the difference in decline in VC (40 vs 30 mL.yr-1) was not significant. Initial VC < 50% of predicted and/or Pa,CO2 > 6 kPa was associated with a poor prognosis. In conclusion, annual decline in vital capacity was not abnormally rapid but annual increase in arterial carbon dioxide tension was higher in patients with a poor outcome. Initial determination of vital capacity and initial and repeated blood gas analysis appear to be useful in identifying high-risk postpolio patients.

[Home respiratory therapy becomes more and more frequent. Increased quality of life via a simplified technique]. / Respiratorbehandling i hemmet allt vanligare. Okad livskvalitet genom förenklad teknik.

Long-term domiciliary ventilation is an effective treatment for chronic hypoventilation due to neuromuscular disease or thoracic deformity. As the majority of patients require assisted ventilation only at night, it is a simple means of improving quality of life, and even sometimes of prolonging life. According to a nationwide enquiry organised by the Swedish Thoracic Society in 1993, 460 patients (5.5 per 100,000 of the population) were using domiciliary ventilation (almost a doubling of the figure of 250 patients reported from a similar survey in 1990). The most prevalent indications were poliomyelitis sequelae (30%), followed by myopathy (21%), idiopathic scoliosis (13%) and tuberculosis sequelae (13%). Eighty per cent of the patients used assisted ventilation only at night, and 60 per cent used non-invasive devices such as a nasal mask.