**10. Summary**

Some limitations of ultrasound include that it is operator or skill dependent and this is a real time diagnosis which might create an obstacle for radiologists to evaluate the ultrasounds retrospectively and in turn underlines the need for neonatologists to be more familiar with this tool. Currently most of the available literature are single center trials, retrospective observational cohorts. We still need more prospective studies doing head to head trials with abdominal radiograph to understand the true value and usefulness of abdominal US. More studies are required to fully validate these assessments in clinical care. Training of radiologist and their sonographers as well as other providers such as neonatologists and surgeons is

**Figure 7.** Sonographic appearance of NEC progression (figure from Epelman et al. 38 need permission).

Bladder aspiration through suprapubic urine collection is ideal to perform under ultrasound guidance over landmark techniques. Ultrasound of the bladder can help determine the size and location of the bladder and the volume of urine in the bladder. Portable ultrasound can significantly improve the diagnostic yield; a minimum volume on ultrasound of 10 mL is associated with a 90% successful bladder aspiration. If the cephalocaudal diameter of the bladder (sagittal view) is >20 mm and the anteroposterior diameter is >15 mm, the success rate approaches 100%.

Lumbar puncture (LP) is a relatively common procedure performed in emergency department and the NICU as part of a complete sepsis evaluation. The LP is typically performed using the "blind" surface landmark guidance. Anecdotally, this technique is reported to be have a high percentage of success. However successful identification of landmarks has been

required before broad adoption of bowel POCUS occurs.

**8. Bladder**

72 Current Topics in Intensive Care Medicine

**9. Lumbar puncture**

Existing and emerging POCUS applications are numerous and promising but more validation for clinical value is required in addition to larger scale training of individuals to learn and become competent in these techniques. Emphasis should be on training all incoming and existing fellows to learn POCUS.
