🔊 POCUS Corner

This single-blind RCT enrolled 123 patients admitted for acute heart failure and randomized them to LUS-guided follow-up (physicians adjusted diuretics based on B-line counts at visits on days 14, 30, 90, and 180) versus standard follow-up (no LUS results visible). Mean LVEF was 39%.

The hazard ratio for the primary composite outcome — urgent visit, hospitalization for worsening HF, or death — was 0.518 in the LUS group (95% CI 0.268–0.998, p=0.049). The number needed to treat to avoid one event was 5. LUS patients received more loop diuretics (91% vs 75%, p=0.02) and improved their 6-minute walk distance by 60 meters versus 37 meters in controls (p=0.023).

Clinical takeaway: When B-lines are visible, act. This proof-of-concept study shows that tracking subclinical congestion with LUS and adjusting diuretics proactively — not waiting for symptoms — cuts decompensation risk by half. The NNT of 5 is one of the most favorable numbers in heart failure management.

This pathophysiology study established the quantitative relationship between ultrasound B-lines and actual extravascular lung water (EVLW) — the direct measure of pulmonary edema severity — using lung gravimetry (the gold standard). Lung specimens from patients with acute lung injury were studied. B-line count correlated directly (r=0.87) with EVLW measured by gravimetry.

The study validated what clinicians had long assumed: B-lines are not a qualitative finding but a quantitative one. Each additional B-line zone with ≥3 B-lines corresponds to a measurable increment in interstitial fluid. A total B-line score of ≥30 across 28 intercostal spaces corresponded to severe pulmonary congestion. The correlation held across different underlying pathologies.

Clinical takeaway: B-lines are not just "present or absent" — they are a surrogate measure of lung water. More zones, more B-lines, more congestion. This provides the physiological rationale for using serial B-line counts to guide diuretic titration: as fluid is removed, B-lines should decrease. If they don't, the diagnosis or the adequacy of treatment should be reconsidered.

This retrospective study at a large academic tertiary care center evaluated emergency physician-performed FoCUS for the detection of regional wall motion abnormalities (RWMA) in patients presenting with suspected ACS, prior to coronary angiography or formal echocardiography. 69 patients were included, 82% of whom underwent urgent or emergency coronary angiography.

Emergency physician FoCUS for RWMA had a sensitivity of 94% (95% CI 82–98), specificity 35% (95% CI 15–61), and accuracy 78% (95% CI 66–87). In patients with angiography-proven occlusive MI (OMI), FoCUS identified RWMA in 87% of cases. Residents (PGY-1 to PGY-3) achieved sensitivity 86% and accuracy 77%; fellows and attendings achieved sensitivity 85% and accuracy 82%.

Clinical takeaway: A positive FoCUS finding (RWMA) in a patient with chest pain and equivocal ECG is a powerful rule-in for OMI — positive LR approaches 1.5, but more importantly, it provides independent visually compelling evidence that should prompt urgent cath lab activation. The absence of RWMA does not rule out OMI (sensitivity is not 100%), but its presence should never be dismissed, even by a trainee.

This prospective study enrolled 250 patients referred for standard TTE for common indications (cardiac function, murmur, stroke, arrhythmia, miscellaneous). Each patient underwent both handheld ultrasound (HHU) and physical examination by separate cardiologists blinded to each other's findings. Standard TTE served as the reference standard.

Of 142 patients with abnormal TTE findings, HHU correctly identified 117 (82%) versus physical examination identifying 67 (47%, p<0.0001). HHU was superior for both valvular disease (71% vs 31%, p=0.0003) and miscellaneous findings (47% vs 3%, p<0.0001). For normal TTE patients, HHU also prompted less unnecessary additional testing (56% vs 82%, p<0.0001), resulting in an estimated cost savings of $63 per patient.

Clinical takeaway: Point-of-care cardiac ultrasound, even with limited training, substantially outperforms the stethoscope and physical exam for detecting clinically relevant cardiac pathology. For the hospitalist or internist, a brief cardiac scan before ordering formal TTE can improve the signal-to-noise ratio of testing and potentially reduce unnecessary downstream imaging.

This landmark validation study prospectively enrolled 83 patients and correlated IVC respiratory motion on 2D subcostal echocardiography with right atrial (RA) pressure measured by right-heart flotation catheter within 24 hours. Expiratory and inspiratory IVC diameters and percent collapse (caval index) were measured 2 cm from the right atrium.

IVC caval index correlated with RA pressure (r=0.75, better than either diameter alone). A caval index ≥50% (IVC collapses more than halfway with inspiration) had an 86% positive predictive value for RA pressure <10 mmHg — consistent with no right-sided congestion. A caval index <50% predicted RA pressure ≥10 mmHg in 89% of patients. The 50% threshold was the optimal discriminator.

Clinical takeaway: IVC collapsibility index is the bedside hemodynamic exam you can do in under 60 seconds: subcostal probe, sniff maneuver, measure collapse. A fully collapsing IVC strongly suggests low-normal RA pressure. A plethoric non-collapsing IVC points toward elevated RA pressure — relevant in HF assessment, cardiac tamponade evaluation, and preload status. This is the paper every cardiologist uses, even if they don't know its name.

This PROSPERO-registered systematic review and meta-analysis searched 7 databases through February 2023 and included 10 studies (n=2,356) evaluating emergency physician-performed POCUS for the diagnosis of acute cholecystitis, compared with surgical pathology or radiology-confirmed final diagnosis as the reference standard.

Pooled sensitivity was 70.9% (95% CI 62.3–78.2%) and specificity was 94.4% (95% CI 88.2–97.5%). The positive likelihood ratio was 12.7 (95% CI 5.8–27.5) and negative likelihood ratio was 0.31 (95% CI 0.23–0.41). Importantly, the high positive LR means that a positive EP-performed POCUS markedly shifts the post-test probability of acute cholecystitis and may be sufficient to mobilize early surgical consultation.

Clinical takeaway: Bedside POCUS for RUQ pain is a powerful rule-in test — specificity 94%, positive LR 12.7. A positive POCUS in the right clinical context (fever, RUQ tenderness, leukocytosis) is compelling enough to call surgery. A negative POCUS does not rule out cholecystitis (sensitivity only 71%) — formal radiology ultrasound remains necessary if clinical suspicion is moderate to high despite a negative bedside scan.

This prospective study enrolled 5 final-year medical students and 3 junior doctors (no prior echocardiography experience) at a single cardiology center. Participants completed a standardized 2-hour bedside tutorial on pocket-sized handheld echocardiography (PHHE), then independently assessed 122 cardiology patients using history, physical examination, ECG, and PHHE — compared against a consultant echocardiographer's diagnosis as the reference standard.

Mean diagnostic accuracy improved from 0.49 ± 0.22 (history + physical exam + ECG alone) to 0.75 ± 0.28 with the addition of PHHE (p<0.001). For LV systolic dysfunction detection specifically, sensitivity improved from 25.9% to 74.1% after PHHE, with specificity maintained at 93.6%.

Clinical takeaway: Two hours of structured training produces a step-change in diagnostic accuracy that months of auscultation training cannot match. The implication is not that students should replace formal echocardiography — it's that the technical barrier to useful bedside cardiac ultrasound is much lower than most educators assume. Short, hands-on, supervised training is sufficient to meaningfully improve clinical assessment.

This systematic review and meta-analysis searched MEDLINE and EMBASE through October 2020 and included 33 studies with 6,062 participants evaluating handheld ultrasound devices (HUD) versus standard TTE for LV dysfunction, wall motion abnormality (WMA), LV dilatation, and LV hypertrophy. Operator experience level was a prespecified subgroup analysis variable.

In experienced operators: pooled sensitivity/specificity for reduced LVEF was 88%/96%; for WMA 85%/95%; for LV dilatation 89%/98%; for LV hypertrophy 85%/91%. Diagnostic odds ratios were substantially lower (but still significant) for inexperienced operators, with the largest gap in LV dilatation and WMA detection. This is the most comprehensive meta-analysis of handheld echo accuracy to date.

Clinical takeaway: Handheld cardiac ultrasound in trained hands is a powerful, near-definitive bedside tool for the most clinically important questions: Is the LV function preserved or reduced? Are there wall motion abnormalities? The high specificity means a positive finding can be trusted. Inexperienced users should focus on simple binary questions (is the LVEF grossly reduced or not?) and refer for formal TTE when more nuanced assessment is needed.