In the Cystic Fibrosis Center at Johns Hopkins, pulmonologists Noah Lechtzin and Natalie West closely watch a young patient exhale into a spirometer, a hand-held device that measures airflow and how well lungs are breathing. They then check the reading on the device that represents this patient’s current peak expiratory flow in one second, or FEV1, a number that for CF patients means so much more than just a number.
“That’s the number we pay most attention to, how fast air can be blown out of the lungs after inhalation,” says Lechtzin. “It’s very predictive of how people are going to do over the long term."
Indeed, FEV1 is a very telling measurement that can signal a decline in lung function or a pending exacerbation, or send a message to the patient’s pulmonologist that aggressive treatments with airway clearance, mucolytics and antibiotics may be needed immediately if not sooner. In CF, the thinking goes, the earlier the detection and treatment of a problem the better the outcome.
But spirometry tests that can send such warning signs tend to be conducted in CF clinics and not patients’ living rooms. More often than not, CF exacerbations are typically detected only when patients are sick enough to seek care.
“When patients aren’t seeing us, we rely on them to call us if they’re having problems, and then we have them come in and measure their pulmonary function,” says Lechtzin. “But too often they run into problems they’re not even aware of, or haven’t bothered them enough where they feel they need to call us.”
Lechtzin and West are trying to turn such scenarios around through the use of spirometry in a different venue – the patient’s home. And it seems to be working. In their six-month pilot study, each of ten young adult patients was given a hand-held spirometry device and asked to measure their FEV1 twice daily and to record their symptoms daily. The results? There were 28 exacerbations detected through home monitoring, but only eight of these were reported by patients to their physicians and treated with antibiotics. Also, of the 28 exacerbations detected, 16 were detected by FEV1 alone, and 12 by both FEV1 and symptoms. Home monitoring detected exacerbations an average of 16 days before patients contacted their care center because of symptoms (Pediatric Pulmonology 2009;44(S32):343-44.)
“Looking at the data on lung function before and after,” Lechtzin says, “it turns out they did a little bit better during the time they were using the meter at home. There they required fewer courses of antibiotics for problems.”
But Lechtzin and West aren’t done. Now they’re parlaying what they’ve learned in a randomized study of adolescents, a group of patients particularly challenged by adherence. After patients record their FVE1 measurements, they will answer a series of multiple choice questions presented on a digital menu on the device itself. Among the questions: Have you changed your medication? Have you noticed more coughing? They will then send their answers via modem to Lechtzin and West, who will compare their data with that of patients receiving standard therapy in clinic.
“By getting feedback on the meters and keeping tabs on how well they’re doing, they’re more likely to use their prescribed therapies and stay healthy,” says West. “This has the potential to influence therapy and tailor therapy.”
“The goal is to catch problems early so we can intervene, keep them healthier without having to see them all the time, and without having them become very sick and hospitalized,” Lechtzin says.