A 29‐year‐old man with type 1 diabetes of 10 years presented with abdominal pain for 2 days. The pain was located in the midepigastrium, was nonradiating, associated with nausea and bilious, nonbloody vomiting. No chest pain or shortness of breath was reported. He also complained of polyuria, polydipsia, and generalized weakness. The patient admitted to taking subcutaneous insulin sporadically, as needed. Evaluation revealed a somnolent, dehydrated male with a heart rate of 106 and a blood pressure of 118/65. The patient had Kussmaul's breathing at 31 breaths per minute with saturation of 96% on room air. Hypothermia was also noted. The patient had clear lungs and normal heart sounds. The abdominal bowel sounds were present, and abdomen was soft and nontender with no guarding or rebound tenderness. The patient had a serum glucose of 692, anion gap of 17, and a metabolic acidosis with arterial pH of 6.94. In addition, there were WBC of 22,000 and elevated creatinine. Admission chest x‐ray was normal. EKG was significant for with T‐wave inversions in inferior leads. An echocardiogram showed a normal ejection fraction and an echodensity causing extrinsic compression of the left atrium. Chest CT scan revealed a bilateral pneumomediastinum extending to the neck. Gastrografin study excluded esophageal rupture. Diagnosis of diabetic ketoacidosis with pneumomediastinum was made.
Pneumomediastinum, or air in the mediastinum, is caused by alveolar rupture, usually by conditions that increase intrathoracic pressure, such as vomiting, coughing, and seizure. The air can leak into pulmonary interstitium and along broncho‐vascular bundles into mediastinum and subcutaneous tissues of chest and neck. Despite that pneumomediastinum complicating DKA is rare, there are several mechanisms causing it. In addition to retching and vomiting, DKA and its deep, involuntary acidotic hyperventilation could create an adequate transalveolar pressure gradient to cause alveolar rupture. Interestingly, there have also been reported cases of pneumomediastinum in the absence of vomiting. Patients usually experience chest discomfort. Shortness of breath is usually attributed to the ketosis. Hamman's sign, a crunching sound heard over the chest, synchronous with heartbeat, has also been documented. The major differential diagnoses include esophageal rupture or Boerhaave's syndrome. This condition with high mortality should be excluded by contrast study or endoscopy. The prognosis for patients with pneumomediastinum complicating DKA is excellent. Treatment of underlying ketoacidosis results in rapid resolution of pneumomediastinum.
Diabetic ketoacidosis is a diagnosis frequently encountered by hospitalists. Physicians need to be aware of its rare complication, pneumomediastinum, and differentiate it from potentially dangerous esophageal rupture.
To cite this abstract:Sykora A, Chenouda D, Miller J. Diabetic Ketoacidosis Complicated by Pneumomediastinum. Abstract published at Hospital Medicine 2013, May 16-19, National Harbor, Md. Abstract 244. Journal of Hospital Medicine. 2013; 8 (suppl 2). https://www.shmabstracts.com/abstract/diabetic-ketoacidosis-complicated-by-pneumomediastinum/. Accessed September 16, 2019.