The effect of influenza vaccination on the incidence of chronic obstructive pulmonary disease exacerbations in the immediate postvaccination period.

BACKGROUND: Influenza vaccination is an important strategy in the prevention of exacerbations in patients with chronic obstructive pulmonary disease (COPD). Despite the proven benefits, there are patients who are reluctant to have this intervention for fear of triggering an exacerbation. There are very few studies looking at the effect of the vaccination on exacerbation rates of COPD in primary care. METHODS: Medical records were obtained from six primary care practices in the Derbyshire area (UK), and 293 pairs of patients were selected. All patients had a diagnosis of COPD based on post bronchodilator spirometry. Patients were matched according to age, sex, severity of COPD and comorbidities. The first group of patients received the influenza vaccination while the other group served as a control (either never received the vaccination or received it at a later date). The incidence of COPD exacerbations of both groups was recorded. RESULTS: There were 21 exacerbations in the control group compared to 11 in the vaccinated group. The difference in exacerbation rates between groups was not statistically significant (McNemar's p=0.11). In the 2 weeks after receiving the influenza vaccination, the risk of experiencing an exacerbation in this group of patients was 0.52 in the vaccinated group compared to the non-vaccinated group (OR 0.52, CI 0.29 to 1.14). CONCLUSION: Patients with COPD should be reassured that the influenza vaccination is safe and does not cause an increase in exacerbations. They should be encouraged to take up the vaccination annually before the onset of winter.

Bronchial inflammation in acute bacterial exacerbations of chronic bronchitis: the role of leukotriene B4.

Neutrophils recruited to the airways in chronic obstructive pulmonary disease (COPD) are thought to mediate tissue destruction. Neutrophil recruitment is increased during bacterial exacerbations. The inflammatory process was studied in patients with an acute exacerbation of COPD in order to ascertain the role of leukotriene B4 (LTB4). The sputum of eight subjects with a bacterial exacerbation of COPD was analysed for neutrophil products (myeloperoxidase, elastase) and chemoattractants (interleukin-8 (IL-8) and LTB4). The contribution of LTB4 to the chemotactic activity of the sputum sol phase was determined using the LTB4 receptor antagonist LY293111. The concentrations of the serum acute phase proteins alpha1-proteinase inhibitor, alpha1-antichymotrypsin and C-reactive protein were measured. All patients received appropriate broad-spectrum antibiotic treatment for 7-14 days. Initially, the sputum myeloperoxidase activity was high, indicating neutrophil influx; this was associated with high levels of IL-8 and LTB4. All these concentrations fell with treatment (p<0.01). The chemotactic activity of the sputum was raised on presentation and fell with treatment (p<0.01). LTB4 contributed approximately 30% of the total chemotactic activity on presentation; this diminished with therapy. All acute phase proteins were raised on presentation and fell with therapy (p<0.01). These findings suggest that leukotriene B4 contributes to neutrophil influx into the airway in chronic obstructive pulmonary disease and may influence disease progression.

Leukotriene B4.

Leukotriene B4 is a pro-inflammatory mediator synthesised in myeloid cells from arachidonic acid. Synthesis is catalysed by 5-lipoxygenase and leukotriene A4 hydrolase and is increased by inflammatory mediators including endotoxin, complement fragments, tumor necrosis factor and interleukins. A nuclear membrane protein, 5-lipoxygenase activating protein, is an essential co-factor for 5-lipoxygenase. Leukotriene B4 induces recruitment and activation of neutrophils, monocytes and eosinophils. It also stimulates the production of a number of proinflammatory cytokines and mediators indicating an ability to augment and prolong tissue inflammation. Elevated levels of leukotriene B4 have been found in a number of inflammatory diseases and levels are related to disease activity in some of these. Initial data from pharmacological inhibition studies support a role for leukotriene B4 in the pathogenesis of neutrophil mediated tissue damage, and treatments which reduce its production or block its effects may prove beneficial in neutrophil mediated inflammatory diseases.

Nalbuphine versus diamorphine early in the course of suspected myocardial infarction.

One hundred and seventy-six consecutive patients with moderate or severe pain of suspected myocardial infarction were randomized to receive nalbuphine less than or equal to 20 mg or diamorphine less than or equal to 5 mg intravenously with metoclopramide 10 mg and were observed over 2 hours. One hundred and forty-two patients (81%) received the test drug outside hospital. The median time from symptom onset to treatment was 135 minutes for the nalbuphine group and 125 minutes for the diamorphine group. Satisfactory pain relief (grade 0 or 1) was similar for both groups at each time assessment. In particular, within 10 minutes of the drug's administration 77% of those receiving nalbuphine and 68% who received diamorphine had satisfactory pain relief. The number of doses of each drug, the number of patients withdrawn from the trial because of unsatisfactory pain relief or recurrence of chest pain were similar for both groups. For those with myocardial infarction there was similar satisfactory pain relief with nalbuphine as diamorphine. No significant deleterious haemodynamic effects or other side-effects occurred. The noncontrolled classification and low addiction potential of nalbuphine allow for its more widespread use in the control of pain of suspected myocardial infarction.