Vietnam: In patients with severe dengue, compensatory reserve Index (CRI) may be a useful non-invasive method for monitoring intravascular volume status, states a recent study published in the journal BMC Medicine. It can predict re-shock onset in severe dengue within 12 h of measurement.
The findings imply that CRI can assist in the early detection of re-shock in dengue patients admitted to ICU and could guide individualized fluid resuscitation strategies in these patients.

Dengue shock syndrome (DSS), one of the major clinical phenotypes of severe dengue, is defined by significant plasma leak, leading to intravascular volume depletion and eventually cardiovascular collapse. The compensatory reserve index (CRI) is a new physiological parameter that is derived from feature analysis of the pulse arterial waveform that tracks real-time changes in central volume.
Based on the above, Huynh Trung Trieu, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam, and colleagues investigated the usefulness of CRI for predicting recurrent shock in severe dengue patients admitted to the ICU.
For this purpose, the researchers performed a prospective observational study in the pediatric and adult intensive care units at the Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. In addition to the continuous recording of the arterial waveform using pulse oximetry, the patients were monitored with hourly clinical parameters and vital signs. The waveform data was wirelessly transmitted to a laptop where it was synchronized with the patient's clinical data.
The researchers recruited 103 patients with suspected severe dengue. Sixty-three patients had the minimum required dataset for analysis. The median age was 11 years.
Following were the key findings of the study:
CRI had a negative correlation with heart rate and moderate negative association with blood pressure.
CRI was found to predict recurrent shock within 12 h of being measured (OR 2.24).
The median duration from CRI measurement to the first recurrent shock was 5.4 h (IQR 2.9–6.8).
A CRI cutoff of 0.4 provided the best combination of sensitivity and specificity for predicting recurrent shock (0.66 and 0.86 respectively).
To conclude, "CRI is a useful non-invasive method for monitoring intravascular volume status in patients with severe dengue."
Reference:
Trieu, H.T., Khanh, L.P., Ming, D.K.Y. et al. The compensatory reserve index predicts recurrent shock in patients with severe dengue. BMC Med 20, 109 (2022). https://doi.org/10.1186/s12916-022-02311-6