Clinical judgment falls short of accurate hypotension prediction during intermittent haemodialysis

Clinical judgment of hypervolemia is often insufficient to predict hypotension during intermittent haemodialysis (IHD), a recent study has found. Using the vascular pedicle width (VPW) may help clinicians in this regard.

Researchers conducted a prospective, observational, single-centre analysis of 248 acute kidney injury patients (median age 68 years, 60.1 percent men) requiring IHD. Hypervolemia was determined through the clinical judgment of managing nephrologists and critical care physicians, who used patient history, symptoms, clinical examinations, and other diagnostic techniques in their analysis. A chest X-ray was used to measure VPW.

Overall, 79 patients developed hypotension during IHD, yielding an incidence rate of 31.9 percent. Sepsis, the use norepinephrine, higher lactate, VPW size, need for mechanical ventilation, and the presence of peripheral oedema were among the notable potential correlates of hypotension.

However, of these, multiple logistic regression found that only the need for norepinephrine (odds ratio [OR], 16, 95 percent confidence interval [CI], 4–65) and VPW size (OR, 0.73, 95 percent CI, 0.65–0.82) remained independent after controlling for covariates.

Nephrologists deemed 109 patients (43.9 percent) as hypervolemic, while intensivists identified 107 patients (43.1 percent) as such. The degree of agreement between the two groups of specialists was weak. Moreover, the specificity of the respective specialists’ clinical judgment for predicting hypotension was 45.6 percent and 15.6 percent, while corresponding sensitivity values were 21.5 percent and 55.4 percent.

Meanwhile, a VPW cutoff of >70 mm had a sensitivity of 86.1 percent and a specificity of 55 percent for predicting hypotension in IHD. Receiver operating characteristic curve analysis confirmed that VPW was the best predictor of hypotension, with an area under the curve of 0.81.