Correct!
5. All of the Above
The life expectancy of cystic fibrosis patients was less than 1 year when it was first described (8). However, there has been remarkable survival improvement, and patients with cystic fibrosis are now expected to live 50 years or longer (9). In many studies, maintenance of pulmonary function has been shown to be associated with survival (10), and aggressive treatment, especially during an acute exacerbation, has been associated with survival (11).
As such, several modalities have been demonstrated to improve pulmonary function or prevent its deterioration and reduce the risk of acute exacerbation. Elkins et al. (6) and Donaldson et al. (12) tested the hypothesis that hypertonic saline can hydrate airway surfaces and reduce the viscosity of mucus plugs based on the volume depletion hypothesis. In these studies, 7% of hypertonic saline compared to normal saline improved lung function (FEV1) and reduced the episode of acute exacerbations that resulted in significantly better exacerbation-free survival (13, 14). Fuchs et al. (15) showed that DNAse reduces the risk of exacerbations and improved pulmonary function as well as quality of life (15). As described in the previous section, constant inflammation is one of the pivotal pathophysiology causes of lung destruction in cystic fibrosis (3), and anti-inflammatory agents have been suggested to possibly preserving lung function. Saiman et al. (16) and Eigen et al. (17) demonstrated high dose ibuprofen and corticosteroids preserved pulmonary function and reduced the risk of acute exacerbation, although long term use of corticosteroids is discouraged due to its side effects. Moreover, bacterial colonization in the mucus plays an important role in disease progression, and prophylactic or maintenance antibiotic treatments with intermittent administration of inhaled tobramycin and azithromycin prevent acute exacerbations in cystic fibrosis patients chronically infected with Pseudomonas (18,19).
Not only pharmacological agents, but also non-pharmacological modalities including percussion and postural drainage, positive expiratory pressure devices, high frequency chest wall oscillating devices and nutrition support are essential components in the management of cystic fibrosis. Additionally, treatments of other diseases associated with cystic fibrosis such as pancreatic insufficiency, cystic fibrosis related diabetes, and osteoporosis/osteopenia are important to extend the life expectancy of cystic fibrosis as well (3).
Later, our patient developed severe hypoxemia and was put on BiPAP. However, hypoxemia was refractory requiring intubation and ICU transfer. The arterial blood gases (ABG) on BiPAP were as follows:
ABG: pH 7.15, pCO2 67.0 mmHg, pO2 77.0 mmHg HCO3- 23.3 meq/L, SaO2 89.2 % on BiPAP (PEEP of 5 cm H2O and pressure support 10 cm H2O)
More than 500 ml of thick secretion was suctioned over the 24 hours after intubation. Sputum culture showed MRSA and Pseudomonas aeruginosa. Subsequent bronchoalveolar lavage (BAL) showed elevated total cell counts of 228 X 106 /ml, WBC 11.4 X 106 /ml, neutrophils 70 %, macrophages 30 %, lymphocytes 7 %, and eosinophils 0 %. Cultures from the BAL sample also demonstrated MRSA, multi drug resistant Pseudomonas aeruginosa and intracellular bacteria (Figure 4).
Figure 4. Culture and sensitivities from the BAL.
What is the best antibiotic treatment in this patient? [(S)=Susceptible, (R)=Resistant] (Click on the correct answer to move to the next panel)