Authors: Naiki H et al.
Cureus, 17(6): e86591, June 2025 DOI: 10.7759/cureus.86591
Summary
This case report describes acute respiratory failure and severe hyperchloremic metabolic acidosis resulting from excessive intravascular absorption of normal saline during hysteroscopic myomectomy. Although isotonic saline is widely considered safer than hypotonic distension media, this case illustrates that large-volume absorption can still lead to life-threatening complications.
A 39-year-old woman undergoing hysteroscopic resection of a 40-mm submucosal myoma developed sudden tachypnea, hypotension, hypoxemia, and metabolic derangements approximately 60 minutes into the procedure. Fluid irrigation volume was not tracked intraoperatively. Arterial blood gas analysis revealed severe metabolic acidosis with marked hyperchloremia and impaired oxygenation. Imaging confirmed pulmonary edema. Progressive respiratory failure necessitated conversion to general anesthesia, endotracheal intubation, and mechanical ventilation with PEEP.
Postoperatively, a markedly positive fluid balance (+7.65 liters) was identified, implicating excessive saline absorption as the cause of pulmonary edema and metabolic acidosis. Cardiac dysfunction was excluded. Management consisted of ventilatory support with PEEP and diuresis using intravenous furosemide. The patient demonstrated rapid improvement in oxygenation and acid–base status, was extubated within 12 hours, and recovered fully without long-term sequelae.
The authors emphasize that while hypotonic irrigation fluids are classically associated with water intoxication syndromes, isotonic normal saline can also cause severe pulmonary and metabolic complications when absorbed in sufficient volumes. Hyperchloremic metabolic acidosis contributed to hemodynamic instability and respiratory compromise in this case, highlighting an underrecognized mechanism of deterioration during hysteroscopic surgery.
Key Points
• Excessive absorption of normal saline can cause pulmonary edema and severe hyperchloremic metabolic acidosis
• Isotonic irrigation fluids are not inherently risk-free during hysteroscopy
• Failure to monitor irrigation fluid balance was a critical contributing factor
• Early arterial blood gas analysis facilitated diagnosis of metabolic and respiratory failure
• Prompt ventilatory support and diuresis led to full recovery
What You Should Know
For anesthesiologists, this case reinforces that fluid overload during hysteroscopic surgery is a real threat regardless of irrigation fluid tonicity. Reliance on “normal saline is safe” can delay recognition of evolving pulmonary edema and metabolic acidosis. Strict fluid deficit monitoring, early physiologic assessment with ABGs, and a low threshold to stage procedures are essential to prevent catastrophic complications. Awareness of hyperchloremic metabolic acidosis as a contributor to hypotension and respiratory failure is particularly important in prolonged or technically difficult hysteroscopic cases.
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