A Study Comparing Continuous Infusion Antibiotics to Standard Treatment for Lung Infections in Cystic Fibrosis

Inclusion Criteria: 1. Patients \>= 18 years of age, 2. Pseudomonas aeruginosa isolated in sputum within the last 12 months, 3. has an acute infective exacerbation, defined by international standards of 2 or more of the following in the last 2 weeks: * change sputum volume or colour, * increased cough, * increased dyspnoea, * increased malaise, fatigue or lethargy, * anorexia or weight loss, * decrease in pulmonary function by 10% or more, or * new radiographic changes Exclusion Criteria: 1. patients \< 18 yrs of age, 2. patients that do not meet the criteria for an acute infective exacerbation, 3. concurrent pulmonary embolism, significant haemoptysis, pneumothorax, or respiratory failure, 4. impaired renal function with an estimated creatinine clearance \< 60 mls/min, 5. patients allergic to ß-lactam antibiotics, 6. aminoglycoside contra-indicated, 7. intravenous antibiotics in the last 2 weeks, prior to this admission, 8. received more than 24 hours of intravenous antibiotics in this admission, 9. previous lung transplantation, 10. pregnancy or lactation, or 11. inability to consent.