Microcirculatory alterations characterize septic shock; increased blood lactate level has been described as markers of microcirculation alteration in patients with septic shock. Although useful, this serological analysis is not always feasible in all settings worldwide. To determine if a prolonged capillary refilling is a predictor of mortality in patients with septic shock. A 10-months prospective cohort study was carried out on 175 patients admitted to the Intensive Care Unit (ICU) with the diagnosis of septic shock. The capillary refilling time (CRT) was evaluated Immediately upon admission and after 6 hours post-resuscitation. Traditional tissue perfusion markers were also used to compare and analyze their predictive value on mortality at 28 days. The area under the ROC curve (AUC) to estimate mortality in patients with septic shock with CRT at admission was 0.666 (0.584-0.748), while at 6 hours was 0.819 (0.753-0.885), with a cut-off point of 4.5 seconds at admission (PPV 52.87% NPV 72.73%) and 3.5 sec at 6 hours (PPV 95.56% NPV 79.23%). In those with CRT > 3.5 seconds at 6 hours, they had a RR of 4.60, while a CRT > 4.5 seconds at admission had a RR of 1.94, with a non-survivor proportion of 95.56% for a CRT > 3.5 sec at 6 hours vs 20.77% for CRT ≤ 3.5 sec (P value < 0.001). The CRT at 6 hours showed significant differences in the survival curves with P-value < 0.001, where for values > 3.5 sec, survival at 28 days was 4.44% vs 79.20% for values ≤ 3.5 sec. CRT is a strong predictor of mortality in patients with septic shock. Evaluating changes in CRT during resuscitation from septic shock might be used as an important clinical tool to predict mortality; especially in low-resources settings where using other biomarkers might be sometimes difficult.

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. 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. 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.