Ultrasound appears to be best in most renal colic clinical scenarios. CT is best in older patients (especially with no stone history), those with tenderness on abdominal exam, and those with uncontrolled pain.
In this randomized trial of anesthetized patients, ultrasound-guided internal jugular venous catheters had a lower arterial puncture rate, pneumothorax rate, catheter misplacement, and access time compared to ultrasound-guided subclavian venous catheterization.
When faced with an equivocal appendix on ultrasound (US), use of secondary findings such as appendix diameter ≥ 7mm, presence of appendicolith, associated inflammatory changes, and WBC count greater than 10,000/mL can increase diagnostic certainty.
In intubated patients, respiratory variation of IVC diameter by 16% had fairly high diagnostic accuracy for predicting fluid responsiveness, but only when the tidal volume (TV) was ≥8 mL/kg and positive end-expiratory pressure (PEEP) ≤5 cm H2O.