To the Editor:
Volpicelli et al.1 recently published an article advocating the usefulness of B-line counts to differentiate and predict pulmonary congestion and hemodynamic congestion in intensive care patients. May I kindly ask the authors1 whether there is any evidence that, as the authors write, “the gross evaluation of left ventricular ejection fraction coupled with B-lines assessment is an easy-to-learn technique?” Experience dictates that this would not, in fact, be the case, as B-lines are poorly reproducible measures with different levels of reliability in different hands, in different clinical subsets, and with different equipment. The authors state that echocardiographic “advanced skill is more expensive in terms of cost and time,” but this is true of any medical expertise, and the cost/benefit ratio of B-line assessment needs to be carefully weighed. Can we really recommend B-line assessment and gross echocardiographic evaluation of ejection fraction (defined abnormal <55%) as a stand-by-alone method of “addressing fluid resuscitation to avoid deleterious effects on the lung function?”
The very wide clinical spectrum observed in this study, including cases of septic shock, liver transplant, cardiogenic pulmonary edema, respiratory failure from chronic pulmonary disease, pneumonia, cardiogenic shock or cardiac arrest, hemorrhagic shock from aortic rupture, respiratory failure (other), severe trauma, acute pancreatitis, and cerebral hemorrhage, may be perceived as a limitation in terms of interpreting the information provided by the results. Although it is true that we are still lacking any quick and easy definitive or established monitoring methods to guide fluid resuscitation, the results of this study cannot be reliably extrapolated to a wide variety of causes of respiratory and circulatory impairment, especially considering the limitations detailed above. Until these shortcomings are overcome, we therefore strongly advise adhering to tried and tested means, no matter how difficult they are to implement.
The author declares no competing interests.