Pathological gas

Some medical conditions are characterized by the presence of pathological gas i.e. gas/air found in a space, tissue, or organ, where it would not normally be expected to be.

Terminology

• the prefix "pneumo" is common, especially when it refers to gas within a body space/cavity, e.g. pneumothorax

• the term "emphysematous" is common when gas is associated with an infectious/inflammatory process, e.g. emphysematous pyelonephritis

Pathology

Etiology

Pathological gas can originate from multiple causes:

• iatrogenic

  • a medical procedure introduces gas from the external environment

    • this might be intentional e.g. instillation of CO₂ as part of laparoscopic surgery

• trauma

• vacuum phenomenon: usually no clinical sequelae

• inflammation

  • via fistula/sinus formation

• gas-forming infection

  • rare despite what many trainees might think

• decompression, e.g. after deep sea diving

• idiopathic, e.g. pneumatosis intestinalis

Specific terms

• biliary tree - pneumobilia (aerobilia)

• bone - osseous pneumatosis

• brain - pneumocephalus

• colon - pneumatosis coli

• epididymis - emphysematous epididymo-orchitis

• gallbladder - emphysematous cholecystitis

• inner ear - pneumolabyrinth

• intracranial - pneumocranium

• joints - pneumarthrosis

• kidney - renal emphysema

• large bowel - pneumatosis coli

• liver - emphysematous hepatitis

• mediastinum - pneumomediastinum

• muscle - emphysematous myositis

• esophagus - emphysematous esophagitis

• orbit - orbital emphysema

• pancreas - emphysematous pancreatitis

• parotid gland - pneumoparotid

• pelvicalyceal system - emphysematous pyelitis

• pericardium - pneumopericardium

• perineum - pneumoperineum

• peritoneum - pneumoperitoneum

• pleural cavity - pneumothorax (rarely: aerothorax)

• prostate - emphysematous prostatitis

• retroperitoneum - pneumoretroperitoneum

• scrotum - pneumoscrotum

• small bowel - pneumatosis intestinalis

• soft tissue - subcutaneous emphysema (or surgical emphysema)

• spinal canal - pneumorrhachis

• stomach - emphysematous gastritis

• testis - emphysematous orchitis

• urinary bladder - emphysematous cystitis

• urine - pneumaturia

• uterus - pneumouterus

• vagina - pneumovagina

• vasculature - gas embolism (e.g. pulmonary)

See also

• emphysema (disambiguation)