Point-of-care lung ultrasound to diagnose the etiology of acute respiratory failure on admission to the pediatric intensive care unit. Online supplemental content.
A line artifact Multiple B line artifact Confluent B line
Sub-pleural consolidation Lobar consolidation Pleural effusion + air bronchograms
e-Figure 1. Sample ultrasound artifacts.
e-Table 1. PICU staff physician initial clinical diagnosis worksheet
Please select the primary etiology causing the patient’s acute respiratory failure
o Asthma o Pneumonia
o Viral pneumonia o Bacterial pneumonia o Aspiration pneumonia o Bronchiolitis
o Pulmonary edema
o Cardiogenic pulmonary edema
o Non-cardiogenic pulmonary edema/fluid overload o Acute respiratory distress syndrome
o Pleural effusion o Pneumothorax
o Other (write in etiology) __________________________________
e-Table 2. Diagnostic features to determine the final diagnosis
Diagnosis Historical and clinical findings Status
asthmaticus
History: Age typically >2 years; history of asthma or reactive airway disease; prior hospitalization or ED visit with wheezing; historically responsive to albuterol
Exam: Diffuse wheezing, typically polyphonic; prolonged, forced expiratory phase; decreased or minimal aeration; few or no
crackles/rhonchi; little nasal congestion or rhinorrhea; afebrile or low grade fever <38.3 C
Labs: Viral panel can be positive or negative; sputum culture typically negative
Imaging: CXR hyper-inflated without consolidation or opacity
Medications administered: Responsive to B-agonist therapy; requires steroids for management; may require adjunctive therapies (heliox, theophylline, magnesium, ipratropium, etc)
Bronchiolitis / viral
pneumonitis
History: No history of responsiveness to albuterol
Exam: Viral prodome may include profuse rhinorrhea and nasal congestion; febrile >38.3 C; migratory crackles with changing exam;
wheezing, though typically not dominant feature; may have decreased or limited aeration
Labs: WBC increased/decreased, can have increased platelets; viral panel typically positive; sputum culture can have elevated leukocytes with negative gram stain & culture
Imaging: CXR hyper-inflated with/without peri-bronchial thickening;
typically no consolidations
Medications administered: Unresponsive to B-agonist therapy; may benefit from hypertonic saline nebulization; naso-tracheal suctioning most helpful therapy
Pneumonia History: Possible history of recurrent aspiration
Exam: Febrile >38.3 C; purulent sputum, change in character of sputum or increased secretions; focal crackles or rhonchi which do not change between exams; may have decreased or limited aeration; typically no wheezing
Labs: WBC increased/decreased, can have increased platelets; viral panel typically negative; sputum culture typically with elevated leukocytes, no epithelial cells, and organism on gram stain; positive tracheal culture;
may have positive blood culture
Imaging: CXR with consolidation or opacity (typically lobar, can be peri- hilar, segmental, interstitial, or nodular) with or without pleural
effusion; persistent consolidation on serial CXR Medications administered: Requires antibiotics Acute
respiratory
History: Known precipitating event within prior 7 days
Exam: Typically febrile >38.3 C; CPAP ≥5 AND S/F ratio <264 OR P/F ratio
distress syndrome
<300; focal crackles or rhonchi which can change between exams;
wheezing typically not dominant feature; may have decreased or limited aeration
Labs: WBC increased/decreased, can have increased platelets; viral panel can be positive or negative depending on etiology; sputum culture can be positive or negative depending on etiology
Imaging: CXR with unilateral (less commonly) or bilateral (more commonly) patchy consolidation or opacity with or without pleural effusion; chest x-ray which is not fully explained by cardiac failure;
chest x-ray not fully explained by fluid overload
Medications administered: Typically fluid restricted with diuretic therapy Congestive heart
failure
History: Age typically ≤2 years and/or known cardiac disease
Exam: Afebrile <38 C; tachypnea with normal or mild WOB; diffuse crackles, typically no wheezing; abnormal heart sounds (murmur, S3, S4);
hepatomegaly
Labs: Normal CBC; viral panel typically negative; elevated BNP
Imaging: CXR with an enlarged heart with/without signs of pulmonary edema (peri-bronchial cuffing, prominent pulmonary vessels); ECHO with decreased LV function, typically EF <55%
Medications administered: Diuretics (typically loop or thiazide diuretics);
may require ACE-I or ARB, digoxin, or B-blocker
Key diagnostic features bolded; ACE-I = angiotensin converting enzyme inhibitor; ARB = angiotensin II receptor blocker; BNP = brain natriuretic peptide; C = Celsius; CBC = complete blood count; CPAP = continuous positive airway pressure; CXR = chest x-ray; ECHO = echocardiogram; EF = ejection fraction;
P/F ratio = ratio of partial pressure of arterial oxygen to fraction of inspired oxygen; S/F ratio = ratio of venous oxygen saturation to fraction of inspired oxygen; WBC = white blood cell count; (1-7).
e-Table 3. Sensitivity and specificity of the ultrasound and clinical diagnosis for restricted cohort
Ultrasound Diagnosis Clinical Diagnosis P-value Bronchiolitis
1Sensitivity Specificity
0.46 (95% CI 0.32–0.61) 0.74 (95% CI 0.58–0.86)
0.83 (95% CI 0.69–0.91) 0.66 (95% CI 0.49–0.79)
0.001 0.581 Pneumonia
Sensitivity Specificity
0.76 (95% CI 0.57–0.89) 0.73 (95% CI 0.59–0.83)
0.52 (95% CI 0.33–0.70) 0.88 (95% CI 0.77–0.94)
0.070 0.077 Status Asthmaticus
Sensitivity Specificity
0.60 (95% CI 0.31–0.83) 0.86 (95% CI 0.76–0.93)
1.00 (95% CI 0.72–1.00) 0.98 (95% CI 0.92–1.00)
0.125
0.021
Restricted cohort, n=76. 1Bronchiolitis/viral pneumonitis. P-value <0.05 considered statistically significant.e-Table 4. Comparison of the ultrasound, clinical, and final diagnosis for restricted cohort
Ultrasound Diagnosis Clinical Diagnosis
Final Diagnosis Bronchiolitis
1Pneumonia SA
2Bronchiolitis
1Pneumonia SA
2Bronchiolitis
1n=41
19 14 8 34 6 1
Pneumonia n=25
5 19 1 12 13 0
SA
2n=10
4 0 6 0 0 10
Restricted cohort, n=76. Moderate agreement between ultrasound and final diagnosis with 58% correct (44/76; 95% CI 0.47–0.68), k=0.33 (95% CI 0.16–0.50), kmax=0.73, k/kmax=0.46 (95% CI 0.22–0.71).
Substantial agreement between the clinical diagnosis and final diagnosis with 75% correct (57/76; 95% CI 0.64–0.83), k=0.56 (95% CI 0.38–0.73), kmax=0.86, k/kmax=0.65 (95% CI 0.44–0.87). 1Bronchiolitis/viral pneumonitis; 2status asthmaticus; bold = correct diagnosis.
e-Table 5. Sensitivity and specificity of the ultrasound diagnosis in patients without and with BPD1
Ultrasound without BPD, n=73 Ultrasound with BPD,
n=14
P-value Bronchiolitis
2Sensitivity Specificity
0.40 (95% CI 0.26–0.55) 0.73 (95% CI 0.56–0.85)
0.62 (95% CI 0.31–0.86) 0.83 (95% CI 0.44–0.97)
0.308 0.776 Pneumonia
Sensitivity Specificity
0.74 (95% CI 0.54–0.87) 0.66 (95% CI 0.52–0.78)
0.83 (95% CI 0.44–0.97) 0.75 (95% CI 0.41–0.93)
0.825 0.776 Status
Asthmaticus Sensitivity Specificity
0.60 (95% CI 0.31–0.83) 0.87 (95% CI 0.77–0.93)
NA
0.93 (95% CI 0.69–0.99)
NA 0.693
1Bronchopulmonary dysplasia, chronic lung disease, chronic respiratory failure, or chronic aspiration diagnosis; 2bronchiolitis/viral pneumonitis; NA = not applicable, no true positive cases (final diagnosis). P- value <0.05 considered statistically significant.
e-Table 6. Comparison of the ultrasound and final diagnosis in patients without and with BPD1
Ultrasound without BPD Ultrasound with BPD Final Diagnosis Bronchiolitis
2Pneumonia SA
3Bronchiolitis
2Pneumonia SA
3Bronchiolitis
2n=40, 8
16 17 7 5 2 1
Pneumonia n=23, 6
5 17 1 1 5 0
SA
3n=10, 0
4 0 6 0 0 0
Fair agreement between ultrasound and final diagnosis in patients without history of BPD with 53%
correct (39/73; 95% CI 0.42–0.64), k=0.27 (95% CI 0.09–0.45), kmax=0.68, k/kmax=0.40 (95% CI 0.15–0.68).
Substantial agreement between the ultrasound and final diagnosis in patients with history of BPD with 71% correct (10/14; 95% CI 0.45–0.88), k=0.47 (95% CI 0.02–0.86), kmax=0.74, k/kmax=0.64 (95% CI 0.04
–
1.00
). 1Bronchopulmonary dysplasia, chronic lung disease, chronic respiratory failure, or chronic aspiration; 2bronchiolitis/viral pneumonitis; 3status asthmaticus; bold = correct diagnosis.e-Table 7. Sensitivity and specificity of the ultrasound and clinical diagnosis in ARDS1 removed cohort
Ultrasound Diagnosis Clinical Diagnosis P-value Bronchiolitis
2Sensitivity Specificity
0.48 (95% CI 0.34–0.62) 0.62 (95% CI 0.43–0.78)
0.68 (95% CI 0.53–0.80) 0.65 (95% CI 0.46–0.81)
0.064 1.000 Pneumonia
Sensitivity Specificity
0.56 (95% CI 0.33–0.77) 0.72 (95% CI 0.59–0.82)
0.31 (95% CI 0.14–0.56) 0.89 (95% CI 0.78–0.95)
0.219 0.049 Status
Asthmaticus Sensitivity Specificity
0.60 (95% CI 0.31–0.83) 0.85 (95% CI 0.74–0.92)
1.00 (95% CI 0.72–1.00) 0.98 (95% CI 0.91–1.00)
0.125 0.021
Patients with any diagnosis (ultrasound, clinical or final) of ARDS removed, n=70. 1Acute respiratory distress syndrome; 2Bronchiolitis/viral pneumonitis. P-value <0.05 considered statistically significant.
e-Table 8. Comparison of the ultrasound, clinical, and final diagnosis in ARDS1 removed cohort
Ultrasound Diagnosis Clinical Diagnosis
4, 5Final
Diagnosis
Bronchiolitis
2Pneumonia SA
3Bronchiolitis
2Pneumonia SA
3Bronchiolitis
2n=44
21 15 8 30 6 1
Pneumonia n=16
6 9 1 9 5 0
SA
3n=10
4 0 6 0 0 10
Patients with any diagnosis (ultrasound, clinical or final) of ARDS removed, n=70. Fair agreement between ultrasound and final diagnosis in patients without any diagnosis of ARDS with 51% correct (36/70; 95% CI 0.40-0.63), k=0.21 (95% CI 0.02–0.40), kmax=0.70, k/kmax=0.30 (95% CI 0.02–0.59).
Moderate agreement between clinical and final diagnosis in patients without any diagnosis of ARDS with 64% correct (45/70; 95% CI 0.53–0.74), k=0.40 (95% CI 0.20–0.58), kmax=0.76, k/kmax=0.52 (95% CI 0.29–
0.74). 1Acute respiratory distress syndrome; 2Bronchiolitis/viral pneumonitis; 3Status asthmaticus,
4Patients with final diagnosis of bronchiolitis also had chosen: undifferentiated respiratory failure (n=3), upper respiratory tract infection (n=1), mucous plugging (n=2), and apnea (n=1); 5Patients with final
diagnosis of pneumonia also had chosen: upper airway obstruction (n=1) and laryngotracheobronchitis (n=1); bold = correct diagnosis.
e-Table 9. Comparison of pediatric POC-LUS studies in the ED and PICU when expert physician, blinded to patient history and clinical course determined the ultrasound diagnosis.
Diagnosis
Varshney, 2016;
n=94
Ozkaya, 2019;
n=145
Tripathi, 2019;
n=91
Current Study;
n=87 Bronchiolitis
Sensitivity
Specificity
46%
(95% CI 34%–58%) 75%
(95% CI 50%–89%)
97%
(95% CI 86%–100%) 99%
(95% CI 95%–100%)
79%
(95% CI NP) NP (95% CI NP)
44%
(95% CI 31%–58%) 74%
(95% CI 59%–85%) Pneumonia
Sensitivity
Specificity
100%
(95% CI 40%–100%) 61%
(95% CI 50%–71%)
81%
(95% CI 67%–91%) 100%
(95% CI 96%–100%)
96%
(95% CI NP) NP (95% CI NP)
76%
(95% CI 58%–88%) 67%
(95% CI 54%–78%)
Asthma Sensitivity
Specificity
0%
(95% CI 0%–23%) 51%
(95% CI 40%–63%)
97%
(95% CI 85%–100%) 99%
(95% CI 95%–100%)
NP (95% CI NP)
NP (95% CI NP)
60%
(95% CI 31%–83%) 88%
(95% CI 79%–94%) Other
Sensitivity
Specificity
Asthma/
pneumonia 50%
(95% CI 7%–93%) 59%
(95% CI 48%–69%)
Non-pulmonary etiologies
100%
(95% CI 85%–100%) 93%
(95% CI 87%–97%)
Overall
63%
(95% CI NP) 43%
(95% CI NP)
NA
NA NP = not provided; NA = not applicable; (8-10)
Supplement references:
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8. Varshney T, Mok E, Shapiro AJ, Li P, et al: Point-of-care lung ultrasound in young children with respiratory tract infections and wheeze. Emerg Med J 2016; 33(9):603-610.
9. Özkaya AK, Başkan Vuralkan F, Ardıç Ş: Point-of-care lung ultrasound in children with non-cardiac respiratory distress or tachypnea. Am J Emerg Med 2019; 37(11):2102-2106.
10. Tripathi S, Ganatra H, Martinez E, Mannaa M, et al: Accuracy and reliability of bedside thoracic ultrasound in detecting pulmonary pathology in a heterogeneous pediatric intensive care unit population. J Clin Ultrasound 2019; 47(2):63-70.
