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09.11.2018

UltraPro halts overprescription of antibiotics

Training of doctors for pulmonary ultrasound
Training of doctors for pulmonary ultrasound

UltraPro: The use of ultrasound by general practitioners and the cooperation of assistants are essential to the success of the new strategy.

​The study of the feasibility of implementing the UltraPro algorithm at the primary care level in surgeries is now completed. The study shows the importance of the use of lung ultrasound by GPs and as well as of cooperation by medical assistants.

Bacterial pneumonia accounts for only 1 out of every 20 acute cases of respiratory infection. However, suspecting this disease is one of the main reasons for overprescription of antibiotics, because it is difficult to distinguish bacterial pneumonia from a viral infection that usually resolves spontaneously. In fact, the two types of infections present with similar symptoms.

To tackle this issue, a team of physicians from different specialities – family medicine and radiology – led by Noémie Boillat-Blanco, a physician in the Infectious Diseases Unit at Lausanne University Hospital (CHUV), developed a new diagnostic method called “UltraPro”. This method uses an algorithm to combine ultrasound examination of the lungs (Ultra) with a procalcitonin test (Pro).

Precisely identifying patients with bacterial pneumonia

Procalcitonin has been used as a biomarker for some 20 years. It accumulates in the blood during a bacterial infection. When the level of procalcitonin is low (<0.25 µg/L), the doctor can avoid having to prescribe antibiotics. “However”, explains Boillat-Blanco, the level of procalcitonin is not a precise tool, because it can be elevated (>0.25 µg/L) in other circumstances, such as bacterial bronchitis, which don’t require taking antibiotics”. For this reason, it is necessary to combine the procalcitonin test with lung ultrasound, which is fast, painless and effective, and which can be done by physicians other than radiologists. Ultrasound can detect the presence of pulmonary infiltrates, which are a clinical sign of bacterial pneumonia.

Patients who have elevated procalcitonin and pulmonary infiltrates can thus be prescribed antibiotic therapy. Under other circumstances, GPs can avoid prescribing antibiotics. “Naturally”, says Boillat-Blanco, “each physician is free to prescribe additional tests in cases of doubt”.

To verify the feasibility of UltraPro in the primary care setting, Boillat-Blanco’s team carried out a pilot study between December 2017 and April 2018. Eight GPs from the polyclinic in Flon participated, and three of them also implemented the study in their primary care practices. The study comprised 20 patients who met pre-established criteria – age 18 or older, no current antibiotic treatment, a cough of less than 21 days’ duration and at least one of the following: fever lasting more than four days, dyspnoea, tachypnoea and/or abnormal lung sounds.

Proper physician training in lung ultrasound is critical

The first step was training the GPs. “We organised a day-long session to familiarise them with the issue of bacterial resistance, the theory of pneumonia as well as the rationale behind the choice of the UltraPro algorithm.” During this session, the physicians also learned how to do lung ultrasounds, says Boillat-Blanco.

The pilot study showed that physicians are well aware of the issue. Lung ultrasound training proved to be a critical step, because the GPs lacked experience, and only half of them felt confident enough to use it on patients. “We thus intensified the training in lung ultrasound and made it more practical”, says Boillat-Blanco. “We added two hours during which the doctors have a chance to practice on patients with bacterial pneumonia. We also provide doctors with a databank of lung ultrasound images to refer to. We encourage them to do ultrasounds on the patients in their routine work-ups to familiarise themselves with the technology.”

Medical assistants play a key role in implementing the UltraPro test

Loïc Lhopitallier, a physician in the Infectious Diseases Unit at CHUV, monitors implementation of the project on the ground. He delivers the UltraPro diagnostic equipment to GP surgeries and trains the doctors and medical assistants in the study procedures. “We provide a kit consisting of a device for testing for procalcitonin, an ultrasound connected to a tablet and software to enter study data”, explains Lhopitallier.

“Because each GP surgery is different, it is important to listen carefully and to adapt the procedure to each situation. We take into account the key role played by medical assistants, who have to take the bloods and do the procalcitonin testing. Once they understand the public health aspect of the study, they willingly accept training and contribute significantly to its effectiveness.”

All the more so, says Noémie Boillat-Blanco, as the medical assistants must also collect blood samples from patients to establish a biobank, which constitutes an important basis for answering other research questions regarding respiratory infections among the population.

The UltraPro diagnostic method is feasible

The pilot study showed that the procalcitonin test can be successfully done in 20 minutes and that GPs are able to perform a good-quality lung ultrasound and interpret it correctly in 15–20 minutes. “In our experience, patients are very cooperative”, explains Willy Gilgien, a family doctor who participated in the study. “In general, they are quite willing to give a little of their time, because they realise that the study can help to reduce the risk of taking antibiotics needlessly.”

Owing to the encouraging results of the pilot study with respect to the feasibility of the UltraPro algorithm in the primary care setting, a randomised clinical study with 42 doctors was begun at the end of August. Each GP will be asked to recruit 15 patients over a period of 15 months. This study will make it possible to assess the impact of the UltraPro algorithm on the prescription of antibiotics and on the clinical outcome of patients. “The study will cover two flu seasons”, says Gilgien, “which will increase the number of patients who qualify for inclusion. Given the sensitivity of the medical profession and patients to the issue of overprescription of antibiotics and the simplicity of the diagnostic method, there is a good chance that, over the next years, UltraPro will become a familiar tool in many GP surgeries”.

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Dr Noémie Boillat Blanco Service des maladies infectieuses
Centre Hospitalier Universitaire Vaudois
Rue du Bugnon 46 1011 Lausanne +41 79 556 16 86 noemie.boillat@chuv.ch