A 44-year-old white man presented with a 3-month history of dry cough and weakness. He had already been treated with antibiotics without any relief. He did not report dyspnea, fever, or expectoration. The patient's medical history was significant for mild arterial hypertension and autoimmune thyroiditis with normal thyroid hormone levels. He was a nonsmoker and had been in excellent health until symptom onset.

A 29-year-old man presented with a 5-month history of worsening dry cough, exertional dyspnea, chest tightness, and palpitations. He had been treated by his primary care physician with trials of guaifenesin/codeine, azithromycin, albuterol, and omeprazole without improvement. He denied wheezing, fever, sweats, anorexia, joint pain, swelling, or rash. He had no past medical history. He denied a history of tobacco smoking or IV drug use. He kept no pets, worked as a manager in an office environment, and had no history of occupational inhalational exposure. He reported using aerosolized insect spray to eradicate bed bugs in his house shortly before the cough began but did not report any acute symptoms when using the spray.

Cystic fibrosis (CF) conductance transmembrane regulator functions as a chloride (Cl-) channel in multiple organs, including the lungs. More than 1,800 disease-associated mutations have been identified, which can be divided into six classes. In patients with CF due to class III gating mutations, ivacaftor produces significant improvement in lung function, weight, reduction in sweat chloride level, and pulmonary exacerbations by enhancing the probability of chloride channel opening (gating). Although the benefit of ivacaftor in CF due to gating mutations is established, its potential role in patients with CF due to class IV conductance mutations is emerging. We report 6 months' prospective stability of lung function, improved BMI, reduced pulmonary exacerbations, and reduction in sweat chloride level in a patient with severe CF and the class IV R117H mutation. High-resolution CT scan also improved, thus highlighting the potential usefulness of ivacaftor in patients with severe CF due to class IV mutations.

Although the benefits of early tracheostomy in patients dependent on ventilators are well established, the reasons for variation in time from intubation to tracheostomy remain unclear. We identified clinical and demographic disparities in time to tracheostomy.

IV fluid represents a basic therapeutic intervention for septic shock. Unfortunately, the optimal administration of IV fluid to maximize patient outcomes and prevent complications is largely unknown.

Oxygen saturation as measured by pulse oximetry/Fio2 (SF) ratio is highly correlated with the Pao2/Fio2 (PF) ratio in patients with ARDS. However, it remains uncertain whether SF ratio can be substituted for PF ratio for diagnosis of ARDS and whether SF ratio might identify patients who are systemically different from patients diagnosed by PF ratio.