To the Editor:

We have read with great interest the recent study “Changes in the corrected carotid flow time can predict spinal anesthesia-induced hypotension in patients undergoing cesarean delivery: an observational study”, published in the J Anesth [1]. However, the article overlooks a critical aspect.

The study mentions that carotid ultrasonography was performed unilaterally. Since carotid arteries are symmetrical structures in the body and blood flow on each side can vary due to different physiological or pathological conditions, conducting measurements on both sides would provide a more comprehensive evaluation.

Bilateral measurement, endorsed by established guidelines, yields a more thorough dataset by considering variations and potential pathologies between both carotid arteries. Such a detailed approach is crucial for precise clinical evaluations and research outcomes [2]. The methodology section of the study does not convincingly justify its preference for measuring one side, a crucial detail to prevent bias. A transparent explanation, whether for superior acoustic windows or a specific criterion like consistently selecting the right side, is essential for the study’s credibility and repeatability.

The study’s dependability is compromised by not providing a solid rationale for bypassing bilateral measurements, potentially leading to misleading clinical interpretations. We urge the authors to reflect on these methodological issues and encourage future studies to adopt a bilateral approach or thoroughly explain any unilateral choices.