The Impact of Thoracic Ultrasound on Clinical Management of Critically Ill Patients (UltraMan): An International Prospective Observational Study

Ten Influential Point-of-Care Ultrasound Papers: 2023 in Review

In an effort to help keep busy clinicians up to date with the latest ultrasound research, our group of experts has selected 10 influential papers from the past 12 months and provided a short summary of each. We hope to provide emergency physicians, intensivists, and other acute care providers with a succinct update concerning some key areas of ultrasound interest.

Setting positive end-expiratory pressure: lung and diaphragm ultrasound

PURPOSE OF REVIEW

The purpose of this review is to summarize the role of lung ultrasound and diaphragm ultrasound in guiding ventilator settings with an emphasis on positive end-expiratory pressure (PEEP). Recent advances for using ultrasound to assess the effects of PEEP on the lungs and diaphragm are discussed.

RECENT FINDINGS

Lung ultrasound can accurately diagnose the cause of acute respiratory failure, including acute respiratory distress syndrome and can identify focal and nonfocal lung morphology in these patients. This is essential in determining optimal ventilator strategy and PEEP level. Assessment of the effect of PEEP on lung recruitment using lung ultrasound is promising, especially in the perioperative setting. Diaphragm ultrasound can monitor the effects of PEEP on the diaphragm, but this needs further validation. In patients with an acute exacerbation of chronic obstructive pulmonary disease, diaphragm ultrasound can be used to predict noninvasive ventilation failure. Lung and diaphragm ultrasound can be used to predict weaning outcome and accurately diagnose the cause of weaning failure.

SUMMARY

Lung and diaphragm ultrasound are useful for diagnosing the cause of respiratory failure and subsequently setting the ventilator including PEEP. Effects of PEEP on lung and diaphragm can be monitored using ultrasound.

Mechanical Power Delivered by Noninvasive Ventilation Contributes to Physio-Anatomical and Clinical Responses to Early Versus Late Proning in COVID-19 Pneumonia

OBJECTIVES

To study: 1) the effect of prone position (PP) on noninvasive ventilation (NIV)-delivered mechanical power (MP) and 2) the impact of MP on physio-anatomical and clinical responses to early versus late PP in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia.

DESIGN

Nonrandomized trial with inverse probability of treatment weighted-matched groups.

SETTING

HUMANITAS Gradenigo Sub-ICU.

PATIENTS

One hundred thirty-eight SARS-CoV-2 pneumonia patients with moderate-to-severe acute hypoxemic respiratory failure (Pa o2 /F io2 ratio < 200 mm Hg) receiving NIV from September 1, 2020, to February 28, 2021 (Ethics approval: ISRCTN23016116).

INTERVENTIONS

Early PP or late PP or supine position.

MEASUREMENTS AND MAIN RESULTS

Respiratory parameters were hourly recorded. Time-weighted average MP values were calculated for each ventilatory session. Gas exchange parameters and ventilatory ratio (VR) were measured 1 hour after each postural change. Lung ultrasonographic scores and circulating biomarkers were assessed daily. MP delivered during the initial 24 hours of NIV (MP [first 24 hr]) was the primary exposure variable. Primary outcomes: 28-day endotracheal intubation and death. Secondary outcomes: oxygen-response, C o2 -response, ultrasonographic, and systemic inflammatory biomarker responses after 24 hours of NIV. Fifty-eight patients received early PP + NIV, 26 late PP + NIV, and 54 supine NIV. Early PP group had lower 28-day intubation and death than late PP (hazard ratio [HR], 0.35; 95% CI, 0.19-0.69 and HR, 0.26; 95% CI, 0.07-0.67, respectively) and supine group. In Cox multivariate analysis, (MP [first 24 hr]) predicted 28-day intubation (HR, 1.70; 95% CI, 1.25-2.09; p = 0.009) and death (HR, 1.51; 95% CI, 1.19-1.91; p = 0.007). Compared with supine position, PP was associated with a 35% MP reduction. VR, ultrasonographic scores, and inflammatory biomarkers improved after 24 hours of NIV in the early PP, but not in late PP or supine group. A MP (first 24 hr) greater than or equal to 17.9 J/min was associated with 28-day death (area under the curve, 0.92; 95% CI, 0.88-0.96; p < 0.001); cumulative hours of MP greater than or equal to 17.9 J/min delivered before PP initiation attenuated VR, ultrasonographic, and biomarker responses to PP.

CONCLUSIONS

MP delivered by NIV during initial 24 hours predicts clinical outcomes. PP curtails MP, but cumulative hours of NIV with MP greater than or equal to 17.9 J/min delivered before PP initiation attenuate the benefits of PP.

Point-of-Care Ultrasonography in a Pulmonary Hypertension Clinic: A Randomized Pilot Study

Pulmonary arterial hypertension (PAH) is a rare condition with the potential to progress to right heart failure. Point-of-Care Ultrasonography (POCUS), used and interpreted in real time at the bedside to further the cardiopulmonary assessment, has the potential to improve the longitudinal care of PAH patients in the ambulatory setting. Patients from PAH clinics at two academic medical centers were randomized to either a POCUS assessment cohort or non-POCUS standard care (ClinicalTrials.gov identifier NCT05332847). The POCUS group received blinded heart, lung, and vascular ultrasound assessments. Thirty-six patients were randomized to the study and followed over time. Mean age was 65 in both groups and majority female (76.5% and 88.9% females in POCUS and control, respectively). Median time for POCUS assessment was 11 min (range 8-16). There were significantly more changes in management in the POCUS group than control (73% vs. 27%, p-value < 0.001). Multivariate analysis revealed that management changes were more likely to occur with a POCUS assessment, with an odds ratio (OR) of 12 when POCUS was added to physical exam vs. OR of 4.6 compared to physical examination alone (p < 0.001). POCUS in the PAH clinic is feasible and, when combined with physical examination, increases the number of findings and results in changes in management without significantly prolonging visit encounters. POCUS may help support clinical evaluation and decision making in ambulatory PAH clinics.