Pneumoperitoneum Related to Cardiopulmonary Resuscitation: A Rare but Important Complication

Dear Editor, Out-of-hospital cardiac arrest (OHCA) is most of the time witnessed by nontrained healthcare personnel. Cardiopulmonary resuscitation (CPR) is started with trained emergency medical staff taking over on arrival. An adequate cardiac compression (CPR) with or without an external compression device is the sine qua non of providing and maintaining central nervous system perfusion. It is recommended to delay definitive airway to allow continued CPR and/or cardiac shock in an OHCA victim. This process is life-saving, an extremely important public health issue, and requires constant education. Like any other life-saving procedure, CPR has some complications related to that including but not limited to rib fractures, dislodgment of lines/tubes, fracture displacements, and cardiac injury. One injury which is rarely thought of and not diagnosed early is stomach perforation and pneumoperitoneum. Here, we describe a case and clinical course with this complication after OHCA. A 37-year-old female patient with a recent history of SARS-Cov2 infection discharged home 3 months ago from the hospital, collapsed at work. She was found to be apneic and unresponsive. Her coworker started the CPR and emergency services called. On arrival at emergency services, she was found to be in ventricular fibrillation. She was shocked and underwent CPR 7 times en route to the emergency department. In the emergency department, she required two more episodes of CPR and shock for return of spontaneous circulation. Her neurological examination after stabilization showed that she was unresponsive, pupils equal and reactive, able to trigger the ventilator, no response to a painful stimulus, and cough reflex was intact. The electrocardiogram did not show any acute myocardial infarction and serum electrolytes were normal. Further workup included imaging studies including computed tomography (CT) scans of the head, chest, and abdomen. Her abdominal CT with intravenous contrast showed a collection of free air next to her stomach [Figure 1]. There was no fluid collection or any pancreatic injury. Due to the question of stomach perforation and risk of worsening intra-abdominal process, targeted temperature management was not initiated and she was kept normothermic. Over the next 72 h, she gradually woke up and was extubated after a stable brain magnetic resonance imaging. Her abdomen was clinically stable and she was able to take a clear liquid diet. The only major injury was acute kidney injury, for which she was started on short-term dialysis.Figure 1: Computed tomography scan of the abdomen showing the presence of free air around the stomach, tracking anteriorly to the umbilical area (red arrows)Pneumoperitoneum especially restricted perforation is a rare and not usually thought of complication after OHCA.[1-4] There is no clear data on the inpatient cardiac arrest population. A recent review of 67 cases showed that this complication should be considered in these patients.[5] Several factors may contribute to these complications. One key factor is having a full stomach at the time of cardiac arrest. During CPR, the aggressive downward movement of the diaphragm can compress stomach contents. If air is present, this compression can lead to perforation [Figure 2]. Additionally, the presence of air in the stomach alone during CPR increases the risk of perforation. Forceful bagging and stomach distension further exacerbate the issue by causing significant dilation and compression. Unfortunately, there is often no opportunity to insert a gastric tube to relieve the trapped air, as the primary focus is on maintaining brain perfusion in the absence of cardiac contractions. The role of central obesity in this process cannot be overlooked. Our patient had a high body mass index (BMI) with central obesity. This condition likely contributed to the complications by combining three factors: a full stomach or air in the stomach, the forceful downward movement of the diaphragm, and the mechanical resistance caused by central obesity. Together, these elements played a critical role in the outcome.Figure 2: Combination impact of factors leading to pneumoperitoneum due to cardiopulmonary resuscitation during cardiac arrest resuscitation. CPR: Cardiopulmonary resuscitationBrain and chest imaging is routinely performed after cardiac arrest to rule out central causes, such as intracranial bleeding or pulmonary embolism. However, stomach imaging is not typically part of the standard evaluation. In our patient’s case, stomach imaging was conducted because the cause of the cardiac arrest remained unclear. Despite extensive published data supporting its use, targeted temperature management (TTM) is commonly employed after cardiac arrest in patients who do not regain consciousness following successful resuscitation. However, an active abdominal perforation should be considered a contraindication for TTM due to the increased risk of infection associated with cooling. This case raises an important question: should routine abdominal imaging be performed to rule out free air or perforation before initiating hypothermia? In conclusion, stomach perforation and pneumoperitoneum after cardiac arrest can be a serious complication, which is often not looked for and will lead to a catastrophic outcome. Doing adequate bag-mask ventilation, looking out for gastric dilatation, avoiding forceful CPR, and awareness of this complication will help clinicians to prevent and diagnose this condition. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for images and other clinical information to be reported in the journal. The guardian understands that names and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.