The New Zealand 1986 very low birth weight cohort as young adults: mapping the road ahead.

BACKGROUND: Very low birth weight (less than 1500 g) is associated with increased morbidity and costs of health care in childhood. Emerging evidence suggests these infants face a range of health and social problems as young adults. We studied all New Zealand very low birth weight infants born in 1986 (when 58% were exposed to antenatal corticosteroids) in infancy, with later follow-up at 7 to 8 years and 23 to 24 years. We now aim to assess the cohort at 26-28 years compared with controls. METHODS/DESIGN: The case sample will comprise a minimum of 250 members of the 1986 New Zealand national very low birth weight cohort (77% of survivors). Outcomes will be compared with a control group of 100 young adults born at term in 1986. Following written informed consent, participants will travel to Christchurch for 2 days of assessments undertaken by experienced staff. Medical assessments include growth measures, vision, respiratory function, blood pressure and echocardiogram, renal function, dental examination and blood tests. Cognitive and neuropsychological functioning will be assessed with standard tests, and mental health and social functioning by participant interview. A telephone interview will be conducted with a parent or significant other person nominated by the respondent to gain a further perspective on the young person's health and functioning. All those born at less than 28 weeks' gestation, plus a random subset of the cohort to a total of 150 cases and 50 controls, will be offered cranial magnetic-resonance imaging. Statistical analysis will examine comparison with controls and long-term trajectories for the very low birth weight cohort. DISCUSSION: The research will provide crucial New Zealand data on the young adult outcomes for very low birth weight infants and address gaps in the international literature, particularly regarding cardiovascular, respiratory, visual and neurocognitive outcomes. These data will inform future neonatal care, provide evidence-based guidelines for care of preterm graduates transitioning to adult care, and help shape health education and social policies for this high risk group. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12612000995875 . Registered 1 October 2012.

Supplemental oxygen effect on hypoxemia at moderate altitude in patients with COPD.

INTRODUCTION: Altitude exposure will cause moderate to severe hypoxemia in patients with chronic obstructive pulmonary disease (COPD). Supplemental oxygen can be used to attenuate this hypoxemia; however, individual response is variable and difficult to predict. The aim of this study was to assess the efficacy of oxygen supplementation in patients with COPD at a barometric pressure similar to that of a commercial aircraft cabin. METHODS: Following sea-level (40 m) arterial blood gases measurements, 18 patients with COPD were driven to altitude (2086 m), where blood gases were repeated at rest and while on 2 L x min(-1) of supplementary oxygen (altitude O2). RESULTS: Ascent from sea level to altitude caused significant hypoxemia (75 +/- 9 vs. 51 +/- 6 mmHg), which was partially reversed by supplemental oxygen (64 +/- 9 mmHg). Oxygen supplementation did not significantly alter PaCO2 levels (vs. altitude PaCO2). There was a significant relationship between the sea-level CaO2 versus the altitude O2 CaO2 (r = 0.89, P < 0.001). There was a significant relationship (r = 0.81, P < 0.001) between altitude-induced desaturation and resaturation with the administration of oxygen. There was a significant negative correlation (r = -0.74, P < 0.001) between baseline K(CO) and the improvement in CaO2 with the administration of oxygen. CONCLUSION: Low-flow supplemental oxygen during acute altitude exposure will partially reverse altitude-induced hypoxemia in patients with COPD. Patients with diffusion impairments are likely to experience the greatest altitude desaturation, but will gain the most benefit from supplemental oxygen. Supplemental oxygen, delivered at 2 L x min(-1), should maintain clinically acceptable oxygenation during commercial air travel in patients with COPD.

Resting and exercise response to altitude in patients with chronic obstructive pulmonary disease.

INTRODUCTION: Exposure to altitude invariably involves some form of physical activity. There are limited data available to help predict the response to activity at altitude in patients with chronic obstructive pulmonary disease (COPD). The aim of the present study was to investigate the response to acute altitude exposure at rest and during exercise in patients with COPD. METHODS: Sea level measures of cardio-pulmonary function were compared to the resting and exercise hypoxemic response at the summit of the Mt. Hutt ski field (2086 m), New Zealand, in 18 patients with COPD. RESULTS: Ascent from sea level to altitude caused significant hypoxemia at rest (PaO2: 75 +/- 9 vs. 51 +/- 6 mmHg), and during a walk test (41 +/- 7 mmHg). At altitude, the walk test distance was reduced by 52%. Sea level PaO2 and SaO2 correlated with resting PaO2 (r = 0.69) and SaO2 (r = 0.79) at altitude. Diffusion capacity corrected for alveolar volume (K(CO)) correlated with resting SaO2 (r = 0.74) and exercise PaO2 (r = 0.75) at altitude. Aerobic capacity correlated with the walk test distance at altitude (r = 0.70). Spirometry, lung volumes, and ventilatory reserve did not correlate with the hypoxemic response to altitude. DISCUSSION: Baseline arterial oxygen levels and K(CO) are key measures in predicting the hypoxemic response to acute altitude exposure in patients with COPD. The impairment in gas exchange associated with COPD is a significant mechanism causing altitude-related hypoxemia in this group.

The development of a community-based spirometry service in the Canterbury region of New Zealand: observations on new service delivery.

In 2008, as part of the changes to develop integrated health care services in the Canterbury region of New Zealand, the local health board in collaboration with general practitioners, respiratory specialists and scientists introduced a programme for general practices to provide laboratory-quality spirometry in the community. The service adhered to the 2005 ATS/ERS international spirometry standards. The spirometry service was provided by trained practice nurses and community respiratory nurses, and was monitored and quality assured by certified respiratory scientists in the Respiratory Physiology Laboratory, Christchurch Hospital and CISO (Canterbury Initiative Services Organisation). These two organisations were responsible for organising training seminars and refresher courses on spirometry technique and interpretation of results. A total of 10 practices have now become approved spirometry providers, with the number of tests carried out in the primary care setting increasing gradually. Consistently high-quality spirometry tests have been obtained and are now presented on a centrally available results database for all hospital and community clinicians to review. Although the service has proved to be more convenient for patients, the tests have not been delivered as quickly as those carried out by the Respiratory Physiology Laboratory. However, the time scales for testing achieved by the community service is considered suitable for investigation of chronic disease. The success of the service has been dependent on several key factors including hospital and clinical support and a centralised quality assurance programme, a comprehensive training schedule and online clinical guidance and close integration between primary and secondary care clinicians.