Lung ultrasound to quantitatively evaluate extravascular lung water content and its clinical significance

Does Point-of-Care Ultrasound Affect Fluid Resuscitation Volume in Patients with Septic Shock: A Retrospective Review

Background

Fixed, large volume resuscitation with intravenous fluids (IVFs) in septic shock can cause inadvertent hypervolemia, increased medical interventions, and death when unguided by point-of-care ultrasound (POCUS). The primary study objective was to evaluate whether total IVF volume differs for emergency department (ED) septic shock patients receiving POCUS versus no POCUS.

Methods

We conducted a retrospective observational cohort study from 7/1/2018 to 8/31/2021 of atraumatic adult ED patients with septic shock. We agreed upon a priori variables and defined septic shock as lactate ≥4 and hypotension (SBP <90 or MAP <65). A sample size of 300 patients would provide 85% power to detect an IVF difference of 500 milliliters between POCUS and non-POCUS cohorts. Data are reported as frequencies, median (IQR), and associations from bivariate logistic models.

Results

304 patients met criteria and 26% (78/304) underwent POCUS. Cardiac POCUS demonstrated reduced ejection fraction in 15.4% of patients. Lung ultrasound showed normal findings in 53% of patients. The POCUS vs. non-POCUS cohorts had statistically significant differences for the following variables: higher median lactate (6.7 [IQR 5.2-8.7] vs. 5.6], p = 0.003), lower systolic blood pressure (77.5 [IQR 61-86] vs. 85.0, p < 0.001), more vasopressor use (51% vs. 34%, p = 0.006), and more positive pressure ventilation (38% vs. 24%, p = 0.017). However, there were no statistically significant differences between POCUS and non-POCUS cohorts in total IVF volume ml/kg (33.02 vs. 32.1, p = 0.47), new oxygen requirement (68% vs. 59%, p = 0.16), ED death (3% vs. 4%, p = 0.15), or hospital death (31% vs. 27%, p = 0.48). There were similar distributions of lactate, total fluids, and vasopressors in patients with CHF and severe renal failure.

Conclusions

Among ED patients with septic shock, POCUS was more likely to be used in sicker patients. Patients who had POCUS were given similar volume of crystalloids although these patients were more critically ill. There were no differences in new oxygen requirement or mortality in the POCUS group compared to the non-POCUS group.

Thoracic Fluid Content in Neonates Presented with Respiratory Distress as a Predictive Tool for Transient Tachypnea of Newborn

INTRODUCTION

 Respiratory conditions are the most common reason for admission of newborns to a neonatal care unit. The index of contractility (ICON) can be used to measure the thoracic fluid content (TFC) in neonates which is a significant parameter in cases presented with transient tachypnea of newborn (TTN).

OBJECTIVE

 The objective was to compare TFC between newborn infants with TTN compared with other causes of respiratory distress (RD). We tested the hypothesis that TFC would be higher in infants with TTN.

STUDY DESIGN

 In total, 105 newborns were enrolled at the delivery room and were categorized into three groups: TTN, other causes of RD, and control, according to physical examination and Chest X-Ray. TFC was measured within the first 6 hours for all infants and at 24 and 48 hours for the first two groups.

RESULTS

 Demographic data showed higher male participants and use of antenatal steroid therapy in RD groups. TFC within the first 6 hours was higher in RD groups. However, TFC at 24 hours of ≤24 mL/kg, and TFC drop rate at 24 hours of >12% are statistically significant discriminators of TTN from non-TTN, with sensitivity and specificity of 97.1 and 47.1%, and 60 and 82.4%, respectively (Fig 1 and 2).

CONCLUSION

 ICON can be used in conjunction with clinical parameters and CXR as a tool for differentiation between TTN and other causes of RD within the first 24 hours of life by using the cutoff value of TFC at 24 hours and TFC drop rate. This will allow earlier and optimum management of different causes of RD.

KEY POINTS

· Thoracic fluid content. · Neonatal respiratory distress. · Newborn.

Lung ultrasound-guided fluid resuscitation in neonatal septic shock: A randomized controlled trial

This randomized controlled trial aimed to determine whether lung ultrasound-guided fluid resuscitation improves the clinical outcomes of neonates with septic shock. Seventy-two patients were randomly assigned to undergo treatment with lung ultrasound-guided fluid resuscitation (LUGFR), or with usual fluid resuscitation (Control) in the first 6 h since the start of the sepsis treatment. The primary study outcome was 14-day mortality after randomization. Fourteen-day mortalities in the two groups were not significantly different (LUGFR group, 13.89%; control group, 16.67%; p = 0.76; hazard ratio 0.81 [95% CI 0.27-2.50]). The LUGFR group experienced shorter length of neonatal intensive care unit (NICU) stays (21 vs. 26 days, p = 0.04) and hospital stays (32 vs. 39 days, p = 0.01), and less fluid was used in the first 6 h (77 vs. 106 mL/kg, p = 0.02). Further, our study found that ultrasound-guided fluid resuscitation can significantly reduce the incidence of acute kidney injury (25% vs. 47.2%, p = 0.05) and intracranial hemorrhage (grades I-II) within 72 h (13.9% vs. 36.1%, p = 0.03). However, no significant difference was found in the resolution of shock within 1 h or 6 h, use of mechanical ventilation or vasopressor support, time to achieve lactate level < 2 mmol/L, and the number of participants developing hepatomegaly in the first 6 h.

CONCLUSION

Lung ultrasound is a noninvasive and convenient tool for predicting fluid overload in neonatal septic shock. Fluid resuscitation guided by lung ultrasound can shorten the length of hospital and NICU stays, reduce the amount of fluid used in the first 6 h, and reduce the risk of acute kidney injury and intracranial hemorrhage.

TRIAL REGISTRATION

Registered in Guangdong Second Provincial General Hospital: 2021-IIT-156-EK, date of registration: November 13, 2021. And ClinicalTrials.gov: NCT06144463 (retrospectively registered).

WHAT IS KNOWN

• Excessive fluid resuscitation in neonates with septic shock had worse outcomes.

WHAT IS NEW

• Lung ultrasound should be routinely used to guide fluid resuscitation in neonatal septic shock.

Lung Ultrasonography Does Not Distinguish between Interstitial and Alveolar Pulmonary Edema

For a long time, lung diseases have been considered the "forbidden zone" for ultrasound diagnosis because the lung is filled with gas, and the ultrasound waves are totally reflected when they encounter gas [...].

Case Report: Lung Ultrasound in Critically Ill Neonates With Lung Diseases: Experience From Several Typical Cases

Lung ultrasound (LUS) can be used to diagnose various neonatal lung diseases. It more sensitively diagnoses pulmonary edema, pneumothorax, pulmonary consolidation, and atelectasis than traditional X-ray and quickly determines the cause of dyspnea. As a component of severe ultrasound, LUS enables rapid bedside visualization of lung diseases and plays a major role in guiding the differential diagnosis of disease, ventilator treatment, and lung recruitment. This study introduced the application of LUS in the diagnosis and treatment of critically ill neonates with lung diseases.