According to the World Health Organization, drowning accounts for approximately 360,000 deaths annually, representing the third leading cause of unintentional injury death worldwide [1]. Seawater drowning induces specific pathophysiological mechanisms: aspiration of hypertonic fluid disrupts alveolar surfactant, promotes osmotic fluid shifts into the alveolar space, and precipitates severe hypoxemia and acidosis [2][3]. Acute respiratory distress syndrome (ARDS) is the most feared pulmonary complication and remains the primary driver of morbidity and mortality in hospitalized drowning victims [4].

Pneumoperitoneum as a complication of drowning is exceptional and has rarely been described in the literature. Its etiology in this context is complex: it may arise from barotrauma secondary to positive-pressure ventilation, from aerophagia during the drowning event, or—as in our case—from a traumatic visceral injury sustained during submersion [5][6]. We present this case given its rarity, the diagnostic challenge it posed, and the surgical management required.

Seawater drowning produces pathophysiological effects distinct from those of freshwater drowning. Aspiration of hypertonic saline (osmolarity ≈ 1000 mOsm/L) draws fluid from the pulmonary vasculature into the alveolar space, disrupts surfactant and causes severe hypoxaemia [2][7]. The expected profile combines intravascular volume depletion with hypernatraemia. Our patient was hypernatraemic and showed peripheral mottling, but he was normotensive on admission and never required vasopressor support, so overt hypovolaemic shock was not documented. The mixed acidosis, hyperlactataemia and hyperglycaemia at presentation reflect the combined effects of tissue hypoperfusion, anaerobic metabolism and the acute stress response.

ARDS is the principal pulmonary complication of drowning. The CT findings of bilateral ground-glass opacities and upper-lobe consolidation were consistent with early ARDS from aspiration-induced lung injury, as previously described [4][8], and the PaO₂/FiO₂ ratio of 196 mmHg under PEEP 5 cm H₂O corresponded to moderate ARDS. The elevations in troponin and creatine kinase are consistent with the hypoxia-related myocardial and skeletal muscle stress documented in severe drowning episodes.

Furosemide and methylprednisolone were administered in this case for suspected drowning-related pulmonary oedema according to the treatment practice used at the time. However, contemporary drowning guidance does not support routine corticosteroid administration and does not recommend routine diuretic therapy for drowning-related pulmonary oedema [3][9][10]. Their use should therefore be interpreted as part of the initial historical management of this patient rather than as evidence-based standard therapy.

The most distinctive feature of this case was the large compressive pneumoperitoneum arising from a gastric laceration—a rare and potentially fatal complication of drowning. Three pathophysiological mechanisms are proposed in the literature [5][6][11][12]:

1) Barotraumatic pneumoperitoneum (Macklin effect): alveolar rupture under positive-pressure ventilation drives air along broncho vascular fascial sheaths into the mediastinum and sub-diaphragmatic space.

2) Aerophagia-related gastric overdistension: panic-driven aerophagia or bag-mask ventilation during resuscitation rapidly inflates the stomach, potentially causing hydrostatic rupture.

3) Traumatic visceral injury: direct mechanical force during submersion causes full-thickness gastric or intestinal laceration.

Three published observations are informative. Petri et al. described a 37-year-old diver who sustained a 4 cm rupture of the lesser gastric curvature after a rapid ascent from 37 metres, attributed to expansion of swallowed air; the size and location of the lesion were identical to those in our patient [13]. Ayub et al. reported a 14-year-old boy with a complete gastro-oesophageal junction avulsion after near-drowning, in whom CT showed pneumomediastinum, pneumoperitoneum and free fluid concentrated at the oesophageal hiatus [14]. A third report described a 7 cm laceration extending from the abdominal oesophagus to the lesser curvature in a drowning victim after approximately two minutes of bystander cardiopulmonary resuscitation including mouth-to-mouth ventilation [15]. Together these reports show that gastric injury can occur in the absence of any obvious external abdominal trauma.

In the present patient, the operative finding of a 4 cm full-thickness lesser-curvature laceration establishes the injury but not its mechanism. The chronology is nevertheless informative: marked abdominal distension was documented on arrival, before intubation and mechanical ventilation, which argues against ventilator-associated barotrauma as the primary cause. No bystander resuscitation was performed, which distinguishes this case from the CPR-related reports and removes chest-compression and mouth-to-mouth hyperinflation from the differential. Acute gastric overdistension by swallowed seawater and air during the submersion is therefore the most plausible mechanism, although direct traumatic injury cannot be entirely excluded. Instrumentation-related injury is unlikely, given the atraumatic nasogastric insertion and the absence of any other lesion. The peri-oesophageal distribution of the pneumomediastinum may reflect a Macklin-type thoracic air dissection [6][16], but may equally represent air tracking upward from the gastric injury through the oesophageal hiatus, as illustrated by the case of Ayub et al. [14].

The distinction between surgical and non-surgical pneumoperitoneum is clinically important. Mechanical ventilation, cardiopulmonary resuscitation, pneumothorax, and other thoracic mechanisms can produce non-surgical pneumoperitoneum [12]. Conversely, free intraperitoneal air accompanied by marked abdominal distension, visceral displacement/compression, clinical deterioration, or evidence of gastrointestinal injury may indicate a surgical emergency. In this patient, the combination of marked abdominal distension and large-volume compressive pneumoperitoneum on CT prompted emergency laparotomy, which confirmed a gastric laceration. CT therefore contributed to the decision-making process but should be performed selectively according to clinical suspicion and patient stability rather than systematically in every drowning victim with abdominal distension.

This case exemplifies the complexity of managing simultaneously an acute respiratory emergency and an acute abdominal surgical emergency in the ICU setting. Close coordination between the intensivist and surgical team, combined with the Trauma Center infrastructure, was essential to the favorable outcome.

We report a rare and life-threatening case of seawater drowning complicated by aspiration-related acute lung injury, pneumomediastinum, and a large-volume pneumoperitoneum caused by a surgically confirmed gastric laceration. The operative lesion was confirmed, whereas its precise mechanism remains uncertain in the absence of external trauma. In drowning patients with marked abdominal distension, clinicians should consider both surgical and non-surgical causes of pneumoperitoneum. CT may be useful when clinical findings raise suspicion for an intra-abdominal complication and the patient’s condition permits imaging. Early multidisciplinary management involving intensive care, anesthesia, radiology, and surgery was central to the favorable outcome.

Written informed consent for publication of the case and associated clinical information was obtained from the patient’s parent. Institutional ethics review requirements were fulfilled according to the applicable institutional policy, with the case report covered by the institution’s approval.

Saile, A., Mouhaoui, B. and Aggoug, B. were responsible for the intensive care management and anesthesia management of the patient and they conceived the case report. Saile, A. performed the literature search and drafted the manuscript. Aggoug, B. supervised the work and critically revised the manuscript. All authors critically revised the manuscript for important intellectual content, read and approved the final version, and agree to be accountable for all aspects of the work.