Pneumothorax (induced by forceful inhalation or high preassure tank siphoning)
Typanic membrane rupture
Tracheal trauma
Air emboli
Bone marrow suppression (from long term exposure)
Leukopenia
Megaloblastic anemia
Thrombocytopenia
Leukopenia
Megaloblastic anemia
Thrombocytopenia
Nitrous oxide toxicity
Pneumothorax 
Chloroform toxicity
Typanic membrane rupture
Carbon disulfide toxicity
Tracheal trauma
Methane toxicity
Air emboli