Narrative review of pediatric sepsis and septic shock: update on ultrasound-guided monitoring, diagnostic criteria and treatment.

Sepsis is a common cause of admission to pediatric intensive care and is associated with high morbidity and mortality. Since 2005, diagnostic criteria have evolved, culminating in the Phoenix Criteria (2023), which define sepsis as organ dysfunction secondary to a dysregulated immune response. Given its heterogeneity, monitoring and treatment should be tailored to the phase of shock. During resuscitation, the goal is to restore perfusion with fluids and vasopressors. In the optimization, stabilization, and de-escalation phases, the aim is to maintain perfusion and remove excess fluids without compromising tissue flow. Current strategies favor a more restrictive fluid approach and an early use of vasoactive drugs. Monitoring should be continuous and multimodal, integrating clinical signs, technology, and laboratory test parameters. In this context, ultrasound has become essential, allowing individualized assessment of volemia, cardiac function, fluid responsiveness, and fluid overload. Ultrasound plays a key role in decision-making throughout the management process.