Ultrasound & Procedures study guide previews.

Central Venous Pressure Measurement Basics introduces the clinical pattern, physiology, and bedside decisions that matter for emergency and critical care practice.

IVC Assessment on US is bedside ultrasound assessment of the IVC diameter and its respiratory variation to estimate intravascular volume status. Why it matters includes simple, fast, non-invasive tool to complement clinical exam and guide resuscitation. Core principle includes the IVC reflects right atrial (RA) pressure and venous return. Collapsibility or distensibility during respiration gives clues about preload and intravascular filling. Use subxiphoid (subcostal) view with curvilinear or phased-array probe.

Measure IVC diameter in long-axis during inspiration & expiration. IVC variation (distensibility) > 18% often suggests fluid responsiveness. Not a stand-alone test - correlation with volume status is imperfect. Confounders include Increased intra-abdominal pressure (ascites, obesity), Elevated intrathoracic pressure (PEEP, high airway pressures), RV dysfunction, pulmonary hypertension, Spontaneous breathing effort (large swings cause overestimation of collapsibility), and Many patients fall in between leading to indeterminate results. Accuracy includes meta-analyses show IVC variation has moderate predictive value for fluid responsiveness, but less reliable than dynamic indices like PPV in ventilated patients.

Strength includes better at ruling out extreme states (very full vs very empty) than guiding fine-tuned fluid therapy. Guidelines includes most major societies recommend IVC assessment as an adjunct rather than sole determinant of fluid management.

The Rapid Ultrasound in Shock and Hypotension protocol is a bedside ultrasound framework for patients with undifferentiated shock. It does not replace clinical judgment or definitive testing, but it can rapidly narrow the differential and guide early resuscitation when the patient is unstable.

The guide organizes RUSH around the classic Pump, Tank, and Pipes approach. Pump evaluates cardiac function and pericardial effusion; Tank evaluates intravascular volume, lung findings, and free fluid; Pipes evaluates major vascular problems such as abdominal aortic aneurysm or venous thrombosis.

The study guide also emphasizes common pitfalls: overcalling volume status from a single IVC view, missing right ventricular strain, ignoring lung ultrasound, and treating RUSH as a one-time exam rather than a repeatable physiologic reassessment tool.

Traditional markers (CVP, edema, IVC alone) are inadequate. VEXUS solves this by include Integrating IVC + venous Doppler patterns, Detecting backward pressure transmission into organs, and VEXUS = multiorgan venous ultrasound assessment. Think include “IVC tells you pressure, Dopplers tell you consequences” and Step 1: IVC Assessment. Key cutoff include cm + minimal collapse leading to high venous pressure.