To the Editor,
Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a
complex, multisystem and often debilitating disorder of unknown
etiology. (1) It is a complicated disease characterized by at least six
months (in pediatrics 3 months) of extreme fatigue that is not
alleviated by rest and a group of other symptoms that are constant for
a period of time. (1)
Post-exertional malaise (PEM) and delayed recovery are core symptoms and
the most useful when making a diagnosis. (2) PEM involves a
constellation of substantially disabling signs and symptoms that occur
in response to physical, mental, emotional, and spiritual over-exertion.
(2) The diagnosis of CFS/ME relies on the typical clinical presentation
and the exclusion of other causes of fatigue. Up until now there was no
test to confirm the diagnosis of CFS/ME. The two-day cardiopulmonary
exercise testing (CPET) is becoming a new diagnostic method that can be
used in case of suspicion of CFS/ME in attempt to evaluate presence of
PEM. (4) This test, used in centres for patients with CFS/ME, has not
yet published any data in pediatrics to support its use.
We present a case of a 13-year-old patient with chronic debilitating
fatigue who meets the criteria for CFS/ME. The patient was examined in
detail by a pediatrician (anamnestic unclear cause, resting tachycardia
in the physical examination, laboratory tests within normal limits),
endocrinologist (normal hormonal profile for a given age, Tanner stage
3), infectologist (serology for typical viruses negative), psychologist
(normal cognitive functions). For a history of resting tachycardia, the
patient was examined by a cardiologist where no cardiogenic cause of
fatigue was demonstrated, sinus tachycardia was present, and the patient
was recommended head-up-tilt test, which showed the presence of postural
orthostatic tachycardia. Due to the idiopathic nature of the
difficulties and the excluded secondary cause, a two-day protocol
examination by cardiopulmonary exercise testing was indicated. Written
consent was taken and documented. Before the examination, we performed
resting spirometry (physiological findings), resting ECG (sinus
tachycardia) and a shortened Schellong test with a tachycardic response
to orthostasis immediately after standing up and after 3 minutes of
standing. Subsequently, standard CPET using treadmill (Itam, Poland)
with individualized protocol with progressive increase in workload until
exhaustion and breath-by-breath analysis of exhaled gases (Geratherm,
Germany) was performed. On the first day, basal values were
determined, the patient subjectively tolerated the examination well, the
exercise ended prematurely due to subjective fatigue and a feeling of
lack of air. On the second day, under the same conditions, the CPET was
repeated, during which the patient also terminated the exercise
prematurely but a half minute later than on the first day (exercise
duration 6:32 min vs. 7:00 min; peak work rate 3,26W/kg vs. 3,68W/kg;
peak VO2 34,5 ml/kg/min vs. 36,5 ml/kg/min). Using this methodology,
patient did not meet diagnostic criteria for PEM and subsequently CFS/ME
(decrease in monitored values on the second day of the examinations). In
both days, during exercise, a bizarre pattern of respiration with
malposition of the respiratory act to the large airways was observed by
observing the flow-volume loop. Analysis of the respiratory pattern
identified an erratic respiratory pattern (figure 1A) with low resting
ETCO2 (26mmHg) and tachypnoea at maximal workload with dominant
ventilation of dead space (figure 1B, 1C, 1G). The consequence of this
pattern of respiration is a chronic state of hypocapnia and respiratory
alkalosis, which is metabolically compensated in the patient. Fatigue
and increased heart rate are expected clinical manifestations.
Respiratory rehabilitation was recommended to the patient in order to
fixate the correct breathing patterns (diaphragmatic breathing) and
psychological guidance. The patient was subsequently retested 3 months
after the start of physiotherapy and psychotherapy at the request of the
parents. Retesting showed significant improvements in the monitored
parameters (figure 1G) as well as in the clinical condition of the
patient. The patient’s overall fitness increased, an adequate resting
respiratory pattern was present (figure 1D), normal resting ETCO2
(36mmHg), ventilatory efficiency was adjusted (figure 1F, 1G), and the
patient reported a subjective increase in energy. Prior to the
examination, we performed a Schellong test on the patient, in which
there were no signs of postural orthostatic tachycardia.
Dysfunctional breathing (DB) is a condition of the airways characterized
by an irregular breathing pattern and changes in the airways that cannot
be attributed to a specific diagnosis and that causes respiratory and
non-respiratory problems. (3) It is not a disease process, but rather
changes in respiratory patterns that disrupt normal respiratory
processes. However, DB can coexist with diseases such as bronchial
asthma or heart disease. The main symptom is shortness of breath or air
hunger, associated with non-respiratory symptoms such as dizziness,
palpitations, cervical spine pain or fatigue. (5) It also plays a role
in chronic fatigue, neck and back pain, fibromyalgia, and some aspects
of anxiety and depression. (5)
The most common type of DB is hyperventilation syndrome, which is
defined as respiration exceeding metabolic requirements, reducing blood
carbon dioxide concentrations below normal values. (3) This changes the
pH of the blood, increases the alkalinity and thus triggers a number of
adaptive changes that cause symptoms. These conditions are non-somatic
in nature and their treatment consists of respiratory rehabilitation by
various techniques (diaphragmatic breathing, Feldenkrais method, Buteyko
method, Pilates) and psychotherapy in order to control impulsive changes
in the respiratory pattern in various situations. (5)
CPET confirmed the presence of DB in the patient based on the low
resting value of ETCO2, the presence of a chaotic pattern of respiration
during resting and exercise with the presence of tachypnoea (with very
low ventilatory efficiency) in maximal exertion. Diagnosis of DB using
CPET is one of the methods of DB diagnostics. Proper respiratory
rehabilitation and psychological guidance resulted in the patient fixing
the respiratory pattern and subsequently eliminating the primary cause
of the examination - chronic fatigue. Patients with CFS/ME are a common
pediatric problem. The current possibilities of diagnostics are enriched
by the possibility of performing CPET which can be a benefit in
differential diagnostics as well as in confirming the diagnosis.