Overview

Definition:
-Vaping-associated lung injury (VAPI), also known as E-cigarette or Vaping Product Use-Associated Lung Injury (EVALI), is an acute, severe pulmonary illness linked to the inhalation of certain substances contained in e-cigarettes or vaping products
-It is characterized by rapid onset of respiratory symptoms and evidence of lung inflammation.
Epidemiology:
-While initially observed in adults, a significant rise in VAPI cases has been reported among adolescents and young adults
-Prevalence data is evolving rapidly, but studies indicate a strong association with the use of tetrahydrocannabinol (THC)-containing vaping products, particularly those obtained from informal sources
-The CDC reported thousands of cases and dozens of deaths primarily in this age group.
Clinical Significance:
-VAPI poses a serious threat to adolescent respiratory health, potentially leading to acute respiratory failure, prolonged hospitalization, and long-term pulmonary sequelae
-Understanding its presentation, diagnosis, and management is critical for pediatricians and residents preparing for DNB and NEET SS examinations, enabling timely intervention and preventing adverse outcomes.

Clinical Presentation

Symptoms:
-Onset typically occurs within days to weeks of vaping
-Common symptoms include progressive dyspnea, cough (often non-productive initially, then may become productive), chest pain (pleuritic or diffuse), fever, chills, and malaise
-Gastrointestinal symptoms such as nausea, vomiting, abdominal pain, and diarrhea are also frequently reported.
Signs:
-Physical examination may reveal tachypnea, tachycardia, hypoxemia (SpO2 < 90% on room air), and diffuse crackles or wheezes on lung auscultation
-Some patients may present with signs of shock
-Cyanosis may be present in severe cases
-Abdominal tenderness can occur.
Diagnostic Criteria:
-The CDC has established case definitions for EVALI
-Key elements include: 1) History of vaping or e-cigarette product use within 90 days before symptom onset
-2) Pulmonary signs and symptoms consistent with VAPI
-3) Chest imaging showing bilateral opacities consistent with VAPI
-4) Exclusion of other infectious or alternative causes of pulmonary infiltrates
-5) No alternative physician-diagnosed condition sufficiently explaining the clinical presentation.

Diagnostic Approach

History Taking:
-A detailed history is paramount
-Inquire about: type of vaping device used (e-cigarette, vape pen, e-hookah)
-specific liquids or substances vaped (nicotine, THC, CBD, flavorings)
-source of vaping products (legal retail, informal market)
-frequency and duration of use
-recent changes in vaping habits
-any associated symptoms
-Red flags include recent initiation of vaping, use of illicit or black-market products, and co-use of other substances.
Physical Examination:
-A thorough respiratory examination is essential, focusing on respiratory rate, presence of accessory muscle use, auscultation for adventitious sounds (crackles, wheezes), and assessment for hypoxemia using pulse oximetry
-General assessment for signs of systemic illness, dehydration, and shock is also crucial.
Investigations:
-Laboratory investigations may include complete blood count (CBC) with differential, basic metabolic panel (BMP), liver function tests (LFTs), creatine kinase (CK), urinalysis, and inflammatory markers (e.g., C-reactive protein, erythrocyte sedimentation rate)
-Arterial blood gas (ABG) analysis is crucial for assessing oxygenation and ventilation
-Imaging includes chest X-ray (CXR) and CT scan of the chest, which typically show bilateral reticular or ground-glass opacities, often with a predilection for the bases
-DPLs may show a lymphocytic or neutrophilic exudate
-Viral and bacterial etiologies should be ruled out through sputum cultures, blood cultures, and respiratory viral panels.
Differential Diagnosis:
-Differential diagnoses include infectious pneumonia (bacterial, viral, fungal), acute respiratory distress syndrome (ARDS) from other causes, hypersensitivity pneumonitis, lipoid pneumonia, eosinophilic pneumonia, drug-induced lung disease, and interstitial lung diseases
-Careful exclusion of these conditions based on clinical, laboratory, and imaging findings is necessary.

Management

Initial Management:
-Immediate discontinuation of all vaping products is the cornerstone of management
-Patients with hypoxemia require supplemental oxygen to maintain adequate saturation
-Severe cases may necessitate intensive care unit (ICU) admission for close monitoring and respiratory support.
Medical Management:
-Corticosteroids are the mainstay of medical therapy, often initiated empirically in moderate to severe cases
-A typical regimen involves intravenous methylprednisolone (e.g., 1-2 mg/kg/day) followed by a slow oral taper, guided by clinical response and imaging
-Broad-spectrum antibiotics should be considered if infection is suspected, but stopped if cultures are negative
-Bronchodilators may be used for wheezing.
Surgical Management:
-Surgical intervention is generally not indicated for VAPI
-However, in extremely severe and refractory cases leading to respiratory failure, extracorporeal membrane oxygenation (ECMO) may be considered as a bridge to recovery or lung transplantation in select patients.
Supportive Care:
-Supportive care includes meticulous fluid management, nutritional support, and continuous cardiorespiratory monitoring
-Patients may require mechanical ventilation if respiratory failure progresses
-Careful management of electrolyte imbalances and pain control is also important.

Complications

Early Complications: Acute respiratory failure requiring mechanical ventilation, pneumothorax, pulmonary edema, ARDS, sepsis, electrolyte disturbances, and multi-organ dysfunction syndrome.
Late Complications:
-Long-term sequelae may include persistent pulmonary fibrosis, reduced lung function (e.g., decreased diffusing capacity), chronic cough, and increased susceptibility to respiratory infections
-Psychological impact and nicotine dependence also warrant consideration.
Prevention Strategies:
-Public health initiatives aimed at educating adolescents about the risks of vaping and the potential for VAPI are crucial
-Stricter regulation of vaping products, including ingredient disclosure and prohibition of certain additives, is essential
-Healthcare providers should routinely screen adolescents for vaping use and counsel them on cessation.

Prognosis

Factors Affecting Prognosis:
-Prognosis is variable and depends on the severity of illness, promptness of diagnosis and treatment, underlying health status, and the specific agents involved
-Patients with milder disease and prompt treatment generally have a good prognosis
-Severe ARDS, delayed treatment, and extensive lung involvement are associated with poorer outcomes.
Outcomes:
-Most adolescents with VAPI experience significant improvement with appropriate medical management and cessation of vaping
-However, a subset may develop chronic respiratory issues
-Mortality rates, though concerning, have decreased with increased awareness and improved management protocols.
Follow Up:
-Adolescents recovering from VAPI should have regular follow-up appointments to monitor for resolution of symptoms, assess lung function, and address any long-term sequelae
-This includes pulmonary function tests and imaging as indicated
-Continued counseling and support for vaping cessation are vital.

Key Points

Exam Focus:
-Recognize VAPI as a diagnosis of exclusion in adolescents with acute respiratory illness and a history of vaping
-Emphasize the role of THC-containing products and illicit sources
-Recall the CDC diagnostic criteria and the importance of corticosteroid therapy.
Clinical Pearls:
-Always ask adolescents about vaping history during respiratory complaints
-A high index of suspicion is needed, especially with a rapid onset of symptoms after starting new vaping products
-Early initiation of steroids in appropriate cases is key to a better outcome.
Common Mistakes:
-Failing to inquire about vaping history, attributing symptoms solely to infection without considering VAPI, delaying steroid initiation, or discharging patients with persistent hypoxemia without adequate follow-up
-Overlooking GI symptoms associated with VAPI.