Monica Avendano

Home mechanical ventilation: a Canadian Thoracic Society clinical practice guideline.

Increasing numbers of patients are surviving episodes of prolonged mechanical ventilation or benefitting from the recent availability of userfriendly noninvasive ventilators. Although many publications pertaining to specific aspects of home mechanical ventilation (HMV) exist, very few comprehensive guidelines that bring together all of the current literature on patients at risk for or using mechanical ventilatory support are available. The Canadian Thoracic Society HMV Guideline Committee has reviewed the available English literature on topics related to HMV in adults, and completed a detailed guideline that will help standardize and improve the assessment and management of individuals requiring noninvasive or invasive HMV. The guideline provides a disease-specific review of illnesses including amyotrophic lateral sclerosis, spinal cord injury, muscular dystrophies, myotonic dystrophy, kyphoscoliosis, post-polio syndrome, central hypoventilation syndrome, obesity hypoventilation syndrome, and chronic obstructive pulmonary disease as well as important common themes such as airway clearance and the process of transition to home. The guidelines have been extensively reviewed by international experts, allied health professionals and target audiences. They will be updated on a regular basis to incorporate any new information.

Tuberculosis Among Tibetan Refugee Claimants in Toronto: 1998 to 2000

BACKGROUND AND OBJECTIVES Between 1998 and 2000, approximately 525 Tibetan people previously living in the United States claimed refugee status in Canada, many of whom were referred to our centers for completion of tuberculosis (TB) screening. We reviewed TB-related outcomes in this cohort, to compare our experience with previously published work, and to assess follow-up after a stay in a low-incidence region. METHODS We performed a retrospective study of all patients of Tibetan origin assessed at our centers (St. Michaels Hospital and West Park Healthcare Centre, both in Toronto) for completion of TB screening, referred because of abnormal chest radiographic findings or positive tuberculin skin test (TST) result. We compared rates of active and drug-resistant TB in our cohort with local and national rates, as well as those previously published in similar groups. RESULTS One hundred eighty-nine individuals were referred to us for assessment, and 181 records were available for review. The mean duration of stay in Canada prior to presentation was 2.6 months, after having spent a mean of 11 months in the United States. Thirty-two percent of patients gave a history of previous TB, and 97% were TST positive. Culture-positive TB was diagnosed in 24 patients (13%, 4,571 per 100,000), 12 patients had at least one drug resistance (50% of cases), and 4 patients were resistant to at least isoniazid and rifampin (multidrug resistant, 17% of cases). INTERPRETATION People from highly TB endemic areas retain a very high risk of active TB and drug resistance, despite an intervening period in a low-prevalence country. It is important to maintain a high degree of suspicion for TB in all people from high-incidence areas. Treatment of all cases of latent TB infection or ongoing medical surveillance is likely justified in this population.

Long term follow-up of ventilated patients with thoracic restrictive or neuromuscular disease.

OBJECTIVE To evaluate the long term effects of home mechanical ventilation (HMV) on pulmonary function, nighttime gas exchange, daytime arterial blood gases, sleep architecture and functional exercise capacity (6 min walk). Patients with respiratory failure attributable to thoracic restrictive disease (TRD) (kyphoscoliosis) or neuromuscular disease (NMD) were assessed, ventilated, trained and followed in a dedicated unit for the care of patients requiring long term ventilation. DESIGN All patients admitted for home ventilation training since 1988 were reviewed. Measurements of lung function, gas exchange during wakefulness and sleep, as well as functional exercise capacity, were recorded before and immediately after the establishment of HMV. Measurements were repeated one to two years, five years and eight to 10 years later. PATIENTS Seventy-four individuals with TRD or NMD who completed the home ventilation training program and continued with HMV during all or part of the day for at least one year were studied. RESULTS Forty patients had TRD. The characteristics of these patients were (mean SE) as follows: age 58 2.4 years; vital capacity (VC) 27% 1.6% predicted, forced expiratory volume in 1 s (FEV1) 25% 1.5% predicted; FEV1/forced VC (FVC) 78% 1.8%. Thirty-four patients had NMD. The characteristics of these patients were as follows: age 44 3.1 years; VC 41% 4.9% predicted, FEV1 44 5.3% predicted; FEV1/FVC 83% 4.2%. There was a significant improvement in distance walked in 6 min (maximum change 51.2 m in patients with NMD and 93.0 m in patients with TRD), daytime partial pressure of arterial carbon dioxide (maximum change 12.9 mmHg in patients with NMD and 10.4 mmHg in patients with TRD) and nighttime partial pressure of arterial carbon dioxide (maximum change 11.7 mmHg in patients with NMD and 18.0 mmHg in patients with TRD) over time (P 0.004). Ventilation resulted in an improvement in partial pressure of arterial oxygen in patients with TRD (68.1 2.8 mmHg to 80.1 3.5 mmHg) and in patients with NMD (52.9 1.7 mmHg to 65.3 2.1 mmHg), although the change was not statistically significant in patients with NMD (P=0.001 in patients with TRD; P=0.105 in patients with NMD). The improvement after ventilation was maintained over several years. Sleep efficiency (75% 18%, 79% 2.2%), the arousal index (13.4 13 events/h, 28.2 17 events/h) and the apnea-hypopnea index (10.1 11.3 events/h, 13.9 9.5 events/h) did not change with time in either patients with TRD or patients with NMD, respectively (P 0.5). CONCLUSIONS HMV was associated with sustained, long term improvements in nighttime and daytime gas exchange in patients with TRD and NMD. Function exercise capacity increased in patients with TRD and in a subgroup of ambulatory patients with NMD. In patients with TRD, these improvements were maintained for up to 10 years after HMV was established.

Clinical InvestigationsTUBERCULOSISTuberculosis Among Tibetan Refugee Claimants in Toronto: 1998 to 2000

BACKGROUND AND OBJECTIVES Between 1998 and 2000, approximately 525 Tibetan people previously living in the United States claimed refugee status in Canada, many of whom were referred to our centers for completion of tuberculosis (TB) screening. We reviewed TB-related outcomes in this cohort, to compare our experience with previously published work, and to assess follow-up after a stay in a low-incidence region. METHODS We performed a retrospective study of all patients of Tibetan origin assessed at our centers (St. Michaels Hospital and West Park Healthcare Centre, both in Toronto) for completion of TB screening, referred because of abnormal chest radiographic findings or positive tuberculin skin test (TST) result. We compared rates of active and drug-resistant TB in our cohort with local and national rates, as well as those previously published in similar groups. RESULTS One hundred eighty-nine individuals were referred to us for assessment, and 181 records were available for review. The mean duration of stay in Canada prior to presentation was 2.6 months, after having spent a mean of 11 months in the United States. Thirty-two percent of patients gave a history of previous TB, and 97% were TST positive. Culture-positive TB was diagnosed in 24 patients (13%, 4,571 per 100,000), 12 patients had at least one drug resistance (50% of cases), and 4 patients were resistant to at least isoniazid and rifampin (multidrug resistant, 17% of cases). INTERPRETATION People from highly TB endemic areas retain a very high risk of active TB and drug resistance, despite an intervening period in a low-prevalence country. It is important to maintain a high degree of suspicion for TB in all people from high-incidence areas. Treatment of all cases of latent TB infection or ongoing medical surveillance is likely justified in this population.

Institutional care for long-term mechanical ventilation in Canada: A national survey

INTRODUCTION No national Canadian data define resource requirements and care delivery for ventilator-assisted individuals (VAIs) requiring long-term institutional care. Such data will assist in planning health care services to this population. OBJECTIVE To describe institutional and patient characteristics, prevalence, equipment used, care elements and admission barriers for VAIs requiring long-term institutional care. METHODS Centres were identified from a national inventory and snowball referrals. The survey weblink was provided from December 2012 to April 2013. Weekly reminders were sent for six weeks. RESULTS The response rate was 84% (54 of 64), with 44 adult and 10 pediatric centres providing data for 428 VAIs (301 invasive ventilation; 127 noninvasive ventilation [NIV]), equivalent to 1.3 VAIs per 100,000 population. An additional 106 VAIs were on wait lists in 18 centres. More VAIs with progressive neuromuscular disease received invasive ventilation than NIV (P<0.001); more VAIs with chronic obstructive pulmonary disease (P<0.001), obesity hypoventilation syndrome (P<0.001) and central hypoventilation syndrome (P=0.02) required NIV. All centres used positive pressure ventilators, 21% diaphragmatic pacing, 15% negative pressure and 13% phrenic nerve stimulation. Most centres used lung volume recruitment (55%), manually (71%) and mechanically assisted cough (55%). Lack of beds and provincial funding were common admission barriers.CONCLUSIONS: Variable models and care practices exist for institutionalized care of Canadian VAIs. Patient prevalence was 1.3 per 100,000 Canadians.

Multidrug-resistant tuberculosis: Treatment and outcomes of 93 patients

BACKGROUND Tuberculosis (TB) remains a leading cause of death worldwide and the emergence of multidrug-resistant TB (MDR TB) poses a threat to its control. There is scanty evidence regarding optimal management of MDR TB. The majority of Canadian cases of MDR TB are diagnosed in Ontario; most are managed by the Tuberculosis Service at West Park Healthcare Centre in Toronto. The authors reviewed 93 cases of MDR TB admitted from January 1, 2000 to December 31, 2011. RESULTS Eighty-nine patients were foreign born. Fifty-six percent had a previous diagnosis of TB and most (70%) had only pulmonary involvement. Symptoms included productive cough, weight loss, fever and malaise. The average length of inpatient stay was 126 days. All patients had a peripherally inserted central catheter for the intensive treatment phase because medications were given intravenously. Treatment lasted for 24 months after bacteriologic conversion, and included a mean (± SD) of 5 ± 1 drugs. A successful outcome at the end of treatment was observed in 84% of patients. Bacteriological conversion was achieved in 98% of patients with initial positive sputum cultures; conversion occurred by four months in 91%. CONCLUSIONS MDR TB can be controlled with the available anti-TB drugs.

Pulmonary and Nonpulmonary Alterations in Duchenne Muscular Dystrophy

OBJECTIVE To describe our experience in managing patients with Duchenne muscular dystrophy. PATIENTS AND METHODS We analyzed the following variables in a group of 27 patients with Duchenne muscular dystrophy: arterial blood gases, lung function before and after mechanical ventilation, oxygen saturation (measured by pulse oximetry), nocturnal PaCO2 (measured transcutaneously by capnography), heart function, and dysphagia. RESULTS The mean (SD) age was 26 (6) years and the mean age at which mechanical ventilation had initiated in the patients was 21 (5) years. Sixty-two percent had undergone tracheostomy and invasive mechanical ventilation. Arterial blood gas levels returned to normal once mechanical ventilation was administered and remained so for the entire treatment period (mean duration of follow-up, 56 [49] months). Thirteen patients had cardiac symptoms and they all presented abnormal electrocardiograms and echocardiograms indicating dilated cardiomyopathy, left ventricular dysfunction, and posterior hypokinesis. Only 9 patients were receiving enteral nutrition (7 through a gastrostomy tube and 2 through a nasogastric tube). The videofluoroscopic swallowing study confirmed that dysphagia was related to neuromuscular disease rather than the presence or not of a tracheostomy. Five patients (18%), 4 of whom were receiving invasive mechanical ventilation, died during the follow-up period. Three patients had serious heart disease. CONCLUSIONS Mechanical ventilation confers clinical benefits and prolongs life expectancy in patients with Duchenne muscular dystrophy. Heart disease and feeding difficulties are determining factors in the prognosis of these patients.

Healthcare utilisation and costs of home mechanical ventilation

Background Individuals using home mechanical ventilation (HMV) frequently choose to live at home for quality of life, despite financial burden. Previous studies of healthcare utilisation and costs do not consider public and private expenditures, including caregiver time. Objectives To determine public and private healthcare utilisation and costs for HMV users living at home in two Canadian provinces, and examine factors associated with higher costs. Methods Longitudinal, prospective observational cost analysis study (April 2012 to August 2015) collecting data on public and private (out-of-pocket, third-party insurance, caregiving) costs every 2 weeks for 6 months using the Ambulatory and Home Care Record. Functional Independence Measure (FIM) was used at baseline and study completion. Regression models examined variables associated with total monthly costs selected a priori using Andersen and Newman’s framework for healthcare utilisation, relevant literature, and clinical expertise. Data are reported in 2015 Canadian dollars (

Clinical Features and Short-term Outcomes of 144 Patients With SARS in the Greater Toronto Area

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Influence of noninvasive positive pressure ventilation on inspiratory muscles.

0.78=₤0.51=€0.71). Results We enrolled 134 HMV users; 95 with family caregivers. Overall median (IQR) monthly healthcare cost was