RESULTS
During the 13-years period, we registered 29 episodes of PE in 27
patients, with an average of 2.2 episodes per year, corresponding to
9.52 per 10.000 admissions. All the patients were Caucasian, with a mean
age of 14.1 ± 4.3 years and 17 (62.9%) were female (Table 1).
Twenty-four patients (88.9%) were adolescents.
One patient presented as a sudden death and autopsy revealed PE, but no
further data was possible to obtain. Twenty episodes occurred in
patients admitted for PE symptoms (outpatients), 18 from the ED and two
from the outpatient clinic. Thirteen (65%) were female and all were
teenagers (mean age 16.0 ± 0,86 years). In this group, the most frequent
presentations were thoracalgia (15/20, 75%), dyspnea (14/20, 70%), DVT
(8/20, 40%) and syncope (6/20, 30%). Other symptoms included fever
(4/20, 20%), anxiety (2/20, 10%), palpitations (1/20, 5%) and
hemoptysis (1/20, 5%). Thirteen patients were tachycardic (13/20, 65%)
and eight hypoxemic (8/20, 40%). In 10 of these patients, the diagnosis
was not established during previous medical examinations that had taken
place before admission, and five had been submitted to complementary
exams, including CXR, blood analysis and ECG, described as normal.
Respiratory infections (2/10, 20%), asthma flare (1/10, (10%)) and
anxiety (2/10, 20%) had been the main alternative diagnosis assumed.
Mean time lag from presentation to diagnosis was 4.8 days (range 0-42
days). All patients had at least one risk factor (average 1.55)
identifiable in clinical history, including oral contraception (13/20,
65%), positive family history (4/20, 20%), obesity (4/20, 20%),
immunomediated disorders (4/20, 20%). and thrombophilia history
(protein S deficiency) (1/20, 5%). Further investigation revealed seven
inherited thrombophilia (7/20, 35%) and two vascular anomalies
(May-Turner Syndrome) (2/20, 10%).
In the inpatient group (n=8), mean age was 9.49 ± 6.14 years, and 63%
(5/8) were male. Clinical presentation included respiratory failure
(4/8, 50%), hemodynamic compromise (2/8, 25%) and hemoptysis (1/8,
12.5%). Three PE (10.7%) were asymptomatic, corresponding to
imagological findings discovered during the investigation of underlying
pathologies (Table 2). Infections (6/8, 75%), reduced mobility (6/8,
75%), the presence of a central venous catheter (CVC) (5/8, 62.5%) and
complex chronic conditions (5/8, 62.5%), such as congenital heart
disease, oncologic or neurologic conditions, were the main risk factors
for PE in the inpatient group.
Details in complementary exams are displayed in Table 3. The diagnosis
was confirmed by CTPA in 82.1% PE (23/28). Nineteen emboli (67.9%) had
a central location. D-dimer assays were positive in all acute PE, not
being performed in three cases: two asymptomatic PE and in a severely
ill patient, in whom CTPA was directly performed. Most PE were
non-massive (46.4%, 13/28), 39.3% (11/28) were submassive and 14.3%
(4/28) were massive (Table 4). Tachycardia was more prevalent in
submassive and massive groups (p = 0.06) and didn´t correlate with
PE-mortality (p=0.519). There were two intra-cardiac thrombi, in
children with complex congenital cardiopathy. Twelve CXR were performed
and were normal in 83.3% of the cases (10/12). Pneumomediastinum (n=1)
and pleural effusions (n=2) were concomitantly described.
The application of the Wells criteria, assuming that an alternative
diagnosis was less likely except in asymptomatic cases, classified
71.4% (20/28) of our PE patients as high risk. The further D-dimer
testing recommended to the lower risk patients were positive, and thus,
would recommend performing CTPA in all but one (asymptomatic) PE
(sensitivity 96%). Application of the PERC criteria correctly
classified 26 patients as PE, except two asymptomatic (sensitivity
92.9%). Hennelly’s et al. pediatric PE model application misclassified
four of our patients as non-risk (sensitivity 85.7%) (two
asymptomatic), and Lee´s et al. model missed two PE, one asymptomatic
(sensitivity 92.9%).
Two patients with intracardiac thrombi underwent surgical thrombectomy.
Fibrinolysis with recombinant tissue plasminogen activator (alteplase)
was performed due to significant right ventricular dysfunction in four
patients, two with hemodynamic instability (massive PE). Anticoagulation
therapy was initiated in all but one patient, due to major simultaneous
hemorrhages. Unfractioned Heparin (UFH) (n=8), Low-molecular-weight
Heparin (LMWH) (n=13) or both (n=6) were initially used, followed by
warfarin. In addition, a patient received an argatroban perfusion due to
heparin-induced thrombocytopenia. Support treatment included
oxygenotherapy (n=12), aminergic support (n=3) and venoarterial
extracorporeal membrane oxygenation (ECMO) in a patient with refractory
hemodynamic instability and hypoxia.
During follow up, three patients started non–vitamin K antagonist oral
anticoagulants (NOAC) (n=2 apixaban, n=1 rivaroxaban), after a variable
period of warfarin. Eight patients were anticoagulated for a defined
period (average nine months).
The average length of hospitalization was 22.5 days (range 2-75). Eight
patients (8/28, 28.6%) were admitted in the PICU (average 12.1 days).
PE-mortality rate was 6.9% (2/29). A further dead occurred during
hospitalization in a patient with acute lymphocytic leukemia, due to
multisystemic dysfunction with multiple infarcts. During follow up (1
month to 12 years), two patients died from unascertained cause, 3.5 and
6 years after PE event (all-cause mortality 5/29,17.2%). Eighteen
patients (64.3%) were submitted to a control CTPA, in average 8.4
months after PE, one presenting a PE recurrence (new territory,
symptomatic). There were five recurrences of thrombotic events including
two PE recurrences and an ischemic cerebrovascular accident.
Furthermore, two patients had PST associated to May-Thurner syndrome and
were proposed for vascular surgery. No anticoagulation hemorrhagic
complications were registered.