The following is a summary of “Capillary refill time response to a fluid challenge or a vasopressor test: an observational, proof-of-concept study,” published in the April 2024 issue of Critical Care by Hernández et al.
Capillary refill time (CRT) role in indicating tissue perfusion, many studies explore its response to a fluid challenge (FC) and vasopressor tests (VPT) aimed at improving mean arterial pressure (MAP) in septic shock patients with persistent CRT abnormalities.
Researchers conducted a retrospective study to investigate how an FC in fluid-responsive patients and a VPT targeting higher MAP in chronically hypertensive, fluid-unresponsive patients affect the direction and magnitude of CRT response.
They included 34 patients suffering from septic shock. Fluid responsiveness was assessed initially, and 9 fluid-responsive patients received a 500 ml FC over 30 minutes. A VPT was conducted by increasing the norepinephrine dose in 25 patients to achieve a MAP of 80–85 mmHg for 30 minutes. Patients underwent a multimodal perfusion and hemodynamic monitoring protocol, with evaluations at baseline and post-intervention.
The results showed a significant decrease in CRT with both tests (from 5 [3.5–7.6] to 4 [2.4–5.1] sec, P=0.008 after the FC; and from 4.0 [3.3–5.6] to 3 [2.6 -5] sec, P=0.03 after the VPT). A CRT response was seen in 7 out of 9 patients after the FC ann 14 out of 25 patients after the VPT. However, CRT worsened in 4 patients in the latter group, all of whom were given a low-dose vasopressin concurrently.
Investigators concluded that fluid boluses benefitted CRT in responsive septic shock patients, while norepinephrine for higher MAP in previously hypertensive patients showed variable effects, warranting further exploration.
Source: annalsofintensivecare.springeropen.com/articles/10.1186/s13613-024-01275-5