Lung injury from inhaling butane hash oil mimics pneumonia

"Dabbing", a relatively new form of THC use which utilizes Butane Hash Oil (BHO), an extraction of dried cannabis containing high levels of butane and terpene byproducts. The extraction process yields a waxy substance that is heated, vaporized and inhaled. We describe a lung injury as a result of BHO use.

A previously healthy 18-year-old female presented to the ED with shortness of breath for 3-4 days. Initial oxygen saturation was 79% on room air. She was refractory to bronchodilators, steroids and supplemental O₂. She has a 1-pack year smoking history and daily BHO abuse. Chest x-ray was positive for bilateral patchy infiltrates with mild hyperinflation. CT was negative for Pulmonary Embolus or other acute pathologic process. Sputum gram stain and blood cultures were negative. Arterial blood gases confirmed a pO2 of 73 mmHg. On physical exam she was tachycardic and tachypneic. Respiratory auscultation showed decreased air entry bilaterally with diffuse expiratory wheezing, bilateral rhonchi and a prolonged expiratory phase. We concluded her severe pneumonitis was secondary to daily BHO inhalation.

Heating BHO to high temperatures, releases up to 75% of THC, compared to 5-20% THC in traditional smoked cannabis. At 978°F terpenes degrade into methacrolein and benzene. Methacrolein is structurally similar to acrolein, a pulmonary irritant, which causes acute lung injury and pulmonary edema in laboratory animals. We hypothesize a mechanism of lung injury and acute respiratory failure secondary to inhalation of high levels of methacrolein and benzene related to relatively novel phenomena of BHO use.