Table 1.

POCUS protocol

Type of ultrasound	Instruments questions	Theoretic considerations
Optical behavior	Diameter optic nerve: right eye (mm); left eye (mm)	A diameter > 5.7 is a noninvasive indication of intracranial hypertension
Neck anatomy	Visualization of great vessels (jugular vein, carotid artery): normal or abnormal	Detection of patency (thrombosis) and anatomical variants or abnormalities
Pulmonary	Lung ultrasound score, 0–36 points	Score increases as pulmonary water increases; indicates pulmonary edema
Pleural	Presence of pleural occupation and estimation of pleural effusion (mL)	Confirmation of diagnosis, volume evaluation and follow-up
Echocardiography overall function	Estimation of left-ventricular systolic function by LVEF (%) and right-ventricular systolic function by TAPSE (mm)	LVEF > 50% and TAPSE > 15 mm is considered normal
Prediction of volume responsiveness	Distensibility index of inferior vena cava (%)	An index > 12% indicates response to intravenous fluid challenges
Estimation of CO	CO (L/min) estimated by left ventricular outflow tract by velocity time integral and diameter	Normal values, 4–6 L/min
Abdominal screening	FAST protocol for presence or absence of intraperitoneal free fluid	Presence of free fluid is abnormal
Biliary	Presence of lithiasis or dilated biliary tract	Biliary tract pathology may be an incidental finding or the cause of critical illness
Renal	Presence of urinary lithiasis or dilated urinary tract	Urinary tract pathology may be an incidental finding or the cause of critical illness
Ultrasound-guided invasive procedures	Venous or arterial access, pleural or abdominal drainage	Ultrasound-guided invasive procedures are more secure, with fewer adverse effects

CO cardiac output, FAST focused assessment with sonography in trauma, IH intracranial hypertension, LVEF left-ventricular ejection fraction, POCUS point-of-care ultrasound, TAPSE tricuspid annular plane systolic excursion