FoCUS I-AIM framework for the regional anesthesiologist
| Pathology | Clinical indication | Acquisition—optimal FoCUS view(s) | Interpretation | Medical decision-making |
| Local anesthetic systemic toxicity (LAST) | Delayed onset of hemodynamic instability following neuraxial or PNB in a patient with no known cardiac disease (±arrhythmias) | PSAX Alternative Acceptable Views: PLAX, A4C, SC4C | PSAX Sluggish, poorly contracting and potential dyssynchronous LV | Provide hemodynamic support (±inotropes or vasopressors) Follow LAST guidelines, including the use of lipid emulsion |
| Aortic stenosis | Urgent or emergent surgery (eg, hip fracture surgery) with inadequate medical workup and an audible systolic murmur on auscultation | PLAX PSAX at the level of AV* | PLAX and PSAX at level of AV* ↓AV cusp mobility ↑ AV cusp thickness/calcification | Urgent Case Formal TTE and cardiology consultation Emergent case Adjust perioperative management:+arterial line, maintain hemodynamics with vasopressors±inotropes throughout induction, escalate postoperative care to stepdown or ICU |
| Hypovolemia | Urgent or emergent surgery with concern for hypovolemia (eg, trauma patient or ESRD following dialysis) | SCIVC PSAX | SCIVC IVC diameter<1.5 cm, >50% collapse with ‘kissing wall sign’ PSAX Hyperdynamic LV with underfilled end-diastolic volume and end-systolic ‘touching’ of the myocardium Note: Emptying depends on afterload | Fluid resuscitation prior to induction Consider gradual induction with epidural over a subarachnoid block |
| Pulmonary embolism (PE) | Suspected massive PE in high-risk patient population (eg, orthopedics or trauma patient) | PSAX A4C or SC4C | PSAX D-shaped septal shift, RV>LV A4C or SC4C RV and RA dilation>LV Intraventricular septal bowing toward LV during systole | Cardiopulmonary resuscitation when necessary Initiate thrombolytic therapy and/or embolectomy |
*Advanced view not discussed in the recommendations.
A4C, apical four-chamber view; AV, aortic valve; ESRD, end-stage renal disease; FoCUS, focused cardiac ultrasound; I-AIM, Indication, Acquisition, Interpretation, and Medical Decision-Making Framework; ICU, intensive care unit; IVC, inferior vena cava view; LAST, local anesthetic systemic toxicity; LV, left ventricle; PLAX, parasternal long axis view; PNB, peripheral nerve block; PSAX, parasternal short axis view; RA, right atrium; RV, right ventricle; SC4C, subcostal four-chamber view; SCIVC, subcostal inferior vena cava view; TTE, transthoracic echocardiogram.