Biot's respiratory pattern under mechanical ventilation: Two case reports and literature review.

Background: Biot's breathing, first described in 1876, remains an underrecognized yet clinically relevant marker of pontomedullary dysfunction. In mechanically ventilated patients, its identification through ventilator waveforms provides an objective correlate of central respiratory control failure. Case presentation: We report two elderly female patients admitted to the intensive care unit for acute neurological deterioration, both requiring invasive mechanical ventilation initially delivered in controlled mandatory modes. After sedation withdrawal and transition to spontaneous ventilation, irregular clusters of breaths interspersed with apneic pauses were observed, consistent with Biot's respiratory pattern. In Case 1, neuroimaging showed a large hemispheric ischemic stroke without radiological evidence of brainstem involvement, suggesting a secondary or functional Biot-like pattern. In Case 2, brain MRI confirmed caudal brainstem ischemic involvement, correlating with the classic bulbar form of Biot's breathing. Both patients evolved with poor neurological outcomes. Conclusion: Mechanical ventilation enables objective documentation of Biot's breathing, transforming a historically clinical sign into a quantifiable physiological marker. Early recognition contributes to prognostic assessment and improves understanding of central respiratory control failure.