Lung herniation post cardiopulmonary resuscitation

S Aggarwal, M Loehrke 
 Department of Internal Medicine, Western Michigan University School of Medicine, Kalamazoo, Michigan, United States

Correspondence Address:
Dr. S Aggarwal
Department of Internal Medicine, Western Michigan University School of Medicine, Kalamazoo, Michigan
United States

Full Text

Sir,

Chest compressions during cardiopulmonary resuscitation (CPR) can be traumatic to patients resulting in rib / sternum fractures. Sternal fractures occur in one out of five resuscitation attempts, and costal fractures occur in one out of three patients, with two-thirds of the patients with costal fractures having three or more fractures in adjacent ribs. [1] We report a rare complication of lung parenchymal herniation post CPR.

A 56-year-old, previously healthy male, had a ventricular fibrillation cardiac arrest and return of spontaneous circulation after 10 minutes of CPR and shocks. He was intubated and hemodynamically stabilized in the Intensive Care Unit (ICU). Therapeutic hypothermia was initiated and then rewarming done after 24 hours. His neurological and cardiorespiratory status gradually improved over the next seven days. He was eventually extubated and placed on Bilevel positive air pressure (BiPAP). However, he started having respiratory distress with decelerating oxygen saturation. He had asymmetric chest wall movements, with the right side expanding more than the left side. He was re-intubated and a computed tomography (CT) scan revealed displaced fractures from the third to the sixth ribs and a herniated right-sided upper and middle lobe of the lung tissue, outside of the rib cage into the pectoralis muscle [Figure 1]. He was immediately taken to the Operating Room (OR), where an emergency repair of a large right lung hernia with a right pectoralis major muscle flap, open-reduction and internal fixation of multiple right-sided rib fractures, and drainage of the right pleural effusion was done, followed by chest tube placement. He had an uneventful recovery, was re-extubated and transferred to the floor. {Figure 1}

The rib fractures our patient received during CPR causedthe patient's lung parenchyma to herniate which was complicated by the initiation of BiPAP therapy. CPR occasionally results in the fracture of the ribs, especially anteriorly at the costochondral junction, due to the absence of external intercostal muscles. Anterior lung herniation accounts for the most herniations post blunt trauma to the chest, especially seat belt-associated injury. Lung herniation post CPR has been very rarely described earlier, and a study conducted by Krischer et al. of 705 post-CPR autopsies did not report even a single case of lung herniation. [2] Most patients with lung herniation remain asymptomatic and a soft, reducible bulging mass may be noted in the chest wall or the neck that changes in size with the respiratory cycle, coughing, or straining. Lung parenchymal hernias may appear as loculated subcutaneous air pockets on the chest X-ray, however, CT is the preferred modality to identify the hernia. [3]

Management is largely conservative in asymptomatic patients, with careful monitoring of the respiratory function and follow-up imaging, to ensure resolution of the hernia. [4] On account of the potential complications, including risk of strangulation of the herniated parenchyma, incarceration, and risk of pneumothorax with the use of mechanical ventilation with positive end-expiratory pressure, surgical intervention may be chosen in appropriate patients, especially those symptomatic, with intractable pain, dyspnea, incarceration or ongoing effusion. [4]

In CPR-induced lung herniation, patients may also be asymptomatic, but clinical suspicion should be high, especially if rib fractures are suspected or confirmed radiographically. Lung herniation should be considered whenever a patient has a bulging mass in the anterior thorax, intractable pain at the site of a potential fracture, ongoing dyspnea with no definite etiology, subcutaneous emphysema, suspicious (especially bloody) pleural effusions or pneumothorax after CPR.

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