A medical examination performed by a doctor and a diagnosis based on it are the essential first steps of treatment. A quick and correct diagnosis may even save the patient’s life. Advanced diagnostic tests are of great importance in such situations.
Antibiotics The majority of patients are only subjected to a clinical examination in the doctor’s office. This includes interviewing the patient about any underlying conditions and medication and checking the visible symptoms.
“Doctors at the health centre learn through experience to evaluate the severity of the patient’s condition. At the emergency department, in particular, the doctor may have only ten minutes per patient, which means that it is not possible to send everyone to the lab for tests,” says Professor Ville Valtonen, head physician responsible for infectious diseases at the Helsinki and Uusimaa Hospital District (HUS).
According to Professor Valtonen, it would definitely be useful to perform more lab tests than is being done today, because mistakes do occur when you are playing with probabilities. For example, antibiotics are unnecessarily prescribed for acute upper respiratory tract infections, even though they are usually caused by a virus and antibiotics are of no use then.
Professor Valtonen says that diagnostic tests should be used at least when the risks of infections are high.
Valtonen says that limited resources force doctors to use diagnostic tests primarily on patients whose infections involve an elevated risk of death.
“We are getting more and more over 65-year-old patients with a primary disease or medication that impairs their resistance against infections. For example, confusion can be the only symptom of pneumonia in an older person. The diagnosis can go very wrong, if the confusion leads the doctor to suspect an ischemic stroke instead of an infection.”
Asthma patients
– a problematic group
Professor Valtonen says that a correct, quick treatment decision is essential particularly in sepsis infections. About 10,000 cases are diagnosed in Finland each year.
“These infections involve an immediate 15–20 per cent mortality risk. Appropriate treatment with antibiotics must be initiated within 24 hours of the onset of infection. This usually means that you have to make the decision when you first see the patient.”
Asthma patients are known to have a higher than normal risk of pneumonia.
CRP test to support
the decision
The CRP test – measurement of the concentration of the so-called C-reactive protein in a blood sample – is an important tool for finding the right treatment. An elevated CRP concentration often indicates a bacterial infection.
A higher CRP value indicates a more severe bacterial infection. In routine measurement, 5 mg/l or less is considered normal.
“A very high CRP concentration, such as above 100 mg/l, suggests a bacterial infection and speaks against a viral infection. This result as such may be a basis for starting antibiotics, providing that the patient’s other symptoms are considered as well. However, the situation is not always quite so simple. A viral infection may later develop into a bacterial infection,” Professor Valtonen admits.
Doctors must play with probabilities. Acute upper respiratory tract infections are many times caused by a virus.
He says that today the CRP test is the most common lab test, along with the blood count. It is also quite useful in the monitoring of the efficacy of antibiotic therapy.
“CRP is frequently used as an indicator of recovery from an infection. When the CRP level is completely normal, it is relatively safe to consider discontinuing the antibiotics.”
Antibiotics
only when necessary
CRP tests help hospitals manage their overall use of antibiotics. The tests are significant also in the prevention of resistance to antibiotics.
Resistance to antibiotics is a result from excessive use of antibiotics. Microbes gradually become resistant to them.
Finland, the other Nordic countries and the Netherlands are the world’s best countries having so far managed antibiotic resistance. As regards the amount of antibiotics used, Finland is in the middle category. About 2.5 million courses of antibiotics are prescribed each year in Finland.
Globally, the resistance problem has become increasingly difficult, while the development of new antibiotics has been stagnating and the costs have increased.
“Resistant E. coli type bacteria are increasing globally. Bacterial strains that can resist all antibiotics are found particularly in Southern Europe. In such circumstances, the treatment of a normal urinary tract infection becomes very difficult. We've already seen a few of these cases in Finland," Ville Valtonen explains.
Text Timo Nykänen | Photos Pekka Holmström