Case Presentation by Dr. Megan Dougherty, MD
CC: unable to obtain due to clinical condition
HPI: The patient is a 19 years old male presenting to the ED from county jail for altered mental status. The patient has been in county jail for 5 days. He has a known history of psychiatric disease for which he was possibly given valproic acid (records are unclear). Per the officer escorting the patient, the patient has eaten or drank anything in several days and was found moaning on the floor shaking prior to arrival and that is why he is at the hospital.
Unable to obtain due to clinical condition
Past Medical History: Psychiatric disease
Surgical history: Unknown
Allergies: None known
Medications: Possibly valproic acid administered at the jail, but no officer was able to verify if and or what medications were administered daily
Family history: Unable to be obtained
Social history: Currently in county jail. Unclear as to whether the patient smokes tobacco, uses alcohol or illicit drugs.
Vitals: Temperature: 39.2, blood pressure: 189/122, heart rate 154, respiratory rate 27, pulse oximetry 92% on room air
Appearance: in acute distress, shaking all four extremities and looking at everyone in the room, moaning
Mental status: making good eye contact, does not speak but continues to moan
Eyes: Pupils are equal and are 4 mm.
HENMT: head: normocephalic, atraumatic. Nose: no nasal discharge or epistaxis. Mouth: mucous membranes are dry and chapped. Throat: mildly erythematous, no tonsillar hypertrophy
Cardiovascular: tachycardic, regular rhythm. There is a good S1 and S2 without any murmurs. 2+ pulses are felt in all extremities. There is no lower extremity edema.
Respiratory: Clear to auscultation bilaterally. There are no wheezes or crackles. The patient is mildly tachypneic but there are no retractions. The patient is moaning.
Abdomen: soft, non tender to palpation. There is no guarding or rigidity
Musculoskeletal: moving all four extremities. There is no tenderness to palpation of any joint.
Neurological: The patient does not follow commands. He has no facial asymmetry. He continues to have rhythmic jerking. He continues to moan incoherently. Patellar and biceps DTRs are 3+ bilaterally. There is no clonus.
Skin: hot and dry. There is no abrasion or rash.
EKG was obtained. It showed sinus tachycardia. Labs were sent. A CT of the head and a chest x-ray were ordered. The patient was given 4 mg of Ativan for agitation. The patient was also given four liters of fluid. He was given 650 mg of acetaminophen rectally.
After you return to the module, you get a call from radiology to come to their lair to help interpret the head CT. This is what they show you.
1. Based on this imaging, what other imaging do you need?
A. soft tissue neck
B. CT neck
C. chest x-ray
D. CT thorax
2. What is the likely source of the subcutaneous emphysema?
C. necrotizing fasciitis
D. injection drug use
3. If imaging modalities chosen do not show source of subcutaneous emphysema, what is the next step?
A. place chest tube
B. consult neurosurgery
C. consult the ICU
D. consult ENT
- C – Chest x-ray- Most common source of subcutaneous emphysema is from the chest.
- B – Pneumothorax
- D – Consult ENT- In the event that no obvious source is found on imaging, the next step would be evaluation of the airway for defects causing the subcutaneous air. ENT did scope the patient in the case and there was no source of the subcutaneous air found in the airway.
While the etiology of this patient’s alteration was not elucidated by the workup performed, the subcutaneous emphysema was cause for alarm for further workup into potential causes that may not have provided a unifying diagnosis. Certainly, infection, ammonia, NMS, or serotonin syndrome, and others were all a consideration in this altered, febrile patient with a history of psychiatric disorder.
Subcutaneous emphysema was first described in 1850, as a complication of a patient with asthma. Subcutaneous emphysema and pneumomediastinum are both known complications of asthma. First descriptions were by Dr. Laennec (who is known as the father of the stethoscope and was the authority on heart and lung sounds in his time) and also by Dr. Hamman. Most common cause of subcutaneous emphysema in modern days is found to be a pneumothorax and/or a chest tube that has become clogged.
Clinical findings of subcutaneous emphysema include soft tissue swelling as well as crepitus to palpation of affected areas. The crunch felt on palpation is sometimes describes as “rice krispies”. This emphysema is typically painless. The subcutaneous emphysema can spread along the soft tissue planes and can extend up to the neck and head if the chest is the primary source. If severe, the subcutaneous emphysema can cause compression of the upper airway and can also cause jugular venous compression. This can lead to airway compromise and possibly cardiovascular compromise. The patients can develop dysphonia and dysphagia when the subcutaneous air dissects into the tissues of the neck. In the most severe cases, the subcutaneous emphysema can be a cause of dyspnea and they may require a tracheostomy. If pneumomediastinum is present, auscultation of heart sounds will reveal Hamman’s sign (or Hamman’s crunch), which is heard on auscultation with heart, sounds a crunching or crackle sound. Pneumomediastinum also typically presents with severe chest pain.
Dr. Hamman first identified the presence of pneumomediastinum in postpartum women; hence Hamman’s sign is heard when there is pneumomediastinum. The pneumomediastinum is likely related to the increased intrathoracic pressure generated when the women is in labor.
There are many case reports of subcutaneous emphysema and pneumomediastinum. Most commonly reported are causes associated with positive pressure ventilation and those following tooth extraction, especially in musicians. Causes of subcutaneous emphysema include but are not limited to: labor and delivery, SCUBA diving, excessive phonation, excessive blowing, positive pressure ventilation, Valsalva type maneuver, asthma, pneumonia, bronchiolitis, tooth extraction, digestive tract surgery IVDA, necrotizing fasciitis, trauma including GSWs and stabbings. When no source of subcutaneous emphysema is found, called spontaneous subcutaneous emphysema. Careful investigation is warranted first before declaring spontaneous subcutaneous emphysema. CT Thorax is helpful in identifying sources in airway or GI tract. If imaging modalities do not show a source, it would be reasonable to have ENT scope the patient to evaluate the airway for any defects.
Management of subcutaneous emphysema is primarily supportive. Treatment of causes such as pneumothorax is warranted. There are case studies of treatment of severe subcutaneous emphysema with bilateral infraclavicular incisions down to the subcutaneous tissue that helps to provide a tract for the air to drain. There are also case reports of placing a subcutaneous drain.
Chotirmall, SH, Morgan, RK. (2014) Subcutaneous emphysema, BMJ Case Reports. doi: 10.1136/bcr-2013-20112
Choo, M, Shin S, Kim J. (1998) A Case of Spontaneous Cervical and Mediastinal Emphysema. J. Korean Medical Society, 13: 223-6.
O’Reilly, P, Chen, HK, Wiseman, R. (2013) Management of extensive subcutaneous emphysema with a subcutaneous drain. Respiratory Case Reports, 1(2): 28-30.
Roquin, A. (2006). Rene Theophile Hyacinthe Laennec (1781-1826): The Man Behind the Stehoscope. Clinical Med