Effect of volume infusion on left atrial strain in acute circulatory failure.

BACKGROUND: Left atrial strain (LAS) is a measure of atrial wall deformation during cardiac cycle and reflects atrial contribution to cardiovascular performance. Pathophysiological significance of LAS in critically ill patients with hemodynamic instability has never been explored. This study aimed at describing LAS and its variation during volume expansion and to assess the relationship between LAS components and fluid responsiveness. METHODS: This prospective observational study was performed in a French ICU and included patients with acute circulatory failure, for whom the treating physician decided to proceed to volume expansion (rapid infusion of 500 mL of crystalloid solution). Trans-thoracic echocardiography was performed before and after the fluid infusion. LAS analysis was performed offline. Fluid responsiveness was defined as an increase in velocity-time integral (VTI) of left ventricular outflow tract ≥ 10%. RESULTS: Thirty-eight patients were included in the final analysis. Seventeen (45%) patients were fluid responders. LAS analysis had a good feasibility and reproducibility. Overall, LAS was markedly reduced in all its components, with values of 19 [15 - 32], -9 [-19 - -7] and - 9 [-13 - -5] % for LAS reservoir (LASr), conduit (LAScd) and contraction (LASct), respectively. LASr, LAScd and LASct significantly increased during volume expansion in the entire population. Baseline value of LAS did not predict fluid responsiveness and the changes in LAS and VTI during volume expansion were not significantly correlated. CONCLUSIONS: LAS is severely altered during acute circulatory failure. LAS components significantly increase during fluid administration, but cannot be used to predict or assess fluid responsiveness.

Expanding safety boundaries in pediatric robotic-assisted laparoscopic surgery: are we protecting our children?

Little is known about the effects of CO2 insufflation (CDI) on cerebral oxygen saturation (CrSO2) during laparoscopy in the pediatric population. In children undergoing robotic-assisted laparoscopic pyeloplasty (RALP), we prospectively assessed the effects of CDI using standard monitoring and cerebral near-infrared spectroscopy (NIRS). We also explored whether a correlation existed between CrSO2 and parameters known to affect cerebral blood flow. Between January 2021 and September 2023, a cohort of consecutive children older than 2 years underwent RALP at Necker-Enfants Malades Hospital in Paris. A ventilation protocol aimed to prevent hypercarbia was implemented. Data collected included standard monitoring parameters and CrSO2 by NIRS. Thirty patients (16 females), mean age 5.5 ± 3.9 (2.0-9.5) years, were included. Twenty-three patients underwent a retroperitoneal approach. The mean baseline CrSO2 value was 83.0 ± 9.8. Mean CrSO2 decreased during progressive CDI, never below baseline values, while standard-monitoring parameters did not significantly change. No significant correlation was detected between CrSO2 and end tidal CO2, or between CrSO2 and mean arterial pressure, at any operative time. During RALP, a gradual CDI doesn't cause pathological derangements of CrSO2. The lack of correlation between CrSO2 and standard parameters affecting cerebral blood flow suggests the likely presence of cerebral autoregulation in our population.