M. Lee

Effects of smoking cannabis on lung function

Although cannabis (or marijuana) is the world’s most widely-used illicit drug, there has been surprisingly little research into its effects on respiratory health. Part of the problem is the inherent difficulty of studying the long-term effects of an illegal habit. It has often been assumed that smoking cannabis will have similar long-term effects to smoking tobacco. Several recent observational studies suggest that this is not the case and that cannabis has quite different effects on the lung function. There are consistent findings that smoking cannabis is associated with large airway inflammation, symptoms of bronchitis, increased airway resistance and lung hyperinflation. The evidence that smoking cannabis leads to features of chronic obstructive pulmonary disease, such as airflow obstruction and emphysema is not convincing. However, there are numerous case reports of bullous emphysema among cannabis smokers. These findings have not been confirmed in systematic analytical studies and probably represent uncommon adverse effects in very heavy cannabis smokers. There is now additional controversial evidence that cannabis is at least an occasional cause of respiratory malignancies, but again the evidence is inconclusive.

Chest Pain Unit (CPU) in the Management of Low to Intermediate Risk Acute Coronary Syndrome: A Tertiary Hospital Experience from New Zealand

BACKGROUND A chest pain unit (CPU) for management of patients with chest pain at low to intermediate risk for acute coronary syndrome (ACS) appears safe and cost-effective. We report our experience with a CPU from March 2005 to July 2009. METHODS Prospective audit of patients presenting with chest pain suggestive of ACS but no high risk features and managed using a CPU, which included; serial cardiac troponins and electrocardiography and exercise tolerance test (ETT) if indicated. Outcomes assessed included three-month readmission rate and one year mortality. RESULTS 2358 patients were managed according to the CPU. Mean age 56 years (17-96 years), 59% men and median stay of 22h (IQR 17-26h). 1933 (82%) were diagnosed as non-cardiac chest pain. 1741 (74%) patients had an ETT. Median time from triage to ETT was 21h (IQR 16-24h). 64 (2.7%) were readmitted within three months. The majority of readmissions, 39 (61%) were for a non-cardiac cause. Twenty patients (1%) were readmitted with ACS. There was no cardiac death after one year of being discharged as non-cardiac chest pain. CONCLUSIONS This study confirms that a CPU with high usage of predischarge ETT is a safe and effective way of excluding ACS in patients without high risk features in a New Zealand setting.

Cardiac dysfunction and N-terminal pro-B-type natriuretic peptide in exacerbations of chronic obstructive pulmonary disease

Elevated levels of B‐type natriuretic peptides among patients with exacerbations of chronic obstructive pulmonary disease (COPD) are associated with higher mortality. The pathophysiology is unclear. To establish if elevated levels of N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) are due to right or left heart dysfunction, we performed echocardiograms in 18 patients admitted to hospital with COPD. Elevated levels of NT‐proBNP were associated with both right and left heart dysfunction and indicate that these patients have biventricular dysfunction rather than isolated right ventricular compromise.

Cardiac dysfunction in exacerbations of chronic obstructive pulmonary disease is often not detected by electrocardiogram and chest radiographs: ECG and chest xray in COPD exacerbations

Cardiac dysfunction is common in exacerbations of chronic obstructive pulmonary disease (COPD), even in patients without clinically suspected cardiac disorders.