IVC:Ao index sensitive indicator for predicting Post-spinal Hypotension – Study

The incidence of post-spinal anesthesia hypotension (PSAH) in 25-75% of post-spinal anesthesia patients is impacted by the patient's preload or volume status. Co-loading with fluids is recommended to prevent PSAH. Predicting volume status and guiding fluid administration can be aided by using the inferior vena cava (IVC) collapsibility index (IVCCI) and caval aorta index (IVC:Ao index), helping to avoid blind fluid administration. Recent study examined the use of inferior vena cava (IVC) collapsibility index (IVCCI) and caval aorta index (IVC:Ao index) to predict the risk of PSAH in patients undergoing elective surgery under spinal anesthesia. The researchers conducted a prospective, single-center, observational study in a tertiary care hospital. They included 69 adult patients (ASA physical status 1 or 2) scheduled for elective surgery under spinal anesthesia. In the immediate pre-operative period, the researchers used ultrasound to measure the IVCCI and IVC:Ao index for each patient.

Study Results

The results showed that 23 out of 69 patients developed PSAH. The analysis revealed that the IVC:Ao index had better sensitivity (0.696 for IVC:Ao index ≤0.810) and specificity (0.717 for IVC:Ao index ≤0.810) in predicting PSAH compared to IVCCI (sensitivity 0.522 and specificity 0.630 for IVCCI ≥33.32%). The researchers also found that age and IVC:Ao index had a statistically significant contribution to the development of PSAH, whereas sex, ASA physical status, BMI, and IVCCI did not.

Conclusion

The study concluded that the IVC:Ao index is a better predictor of PSAH than IVCCI. Therefore, the IVC:Ao index may be used to assess volume status and guide fluid administration during spinal anesthesia to prevent hypotension. The researchers acknowledged that the sample size was limited due to the COVID-19 pandemic, and further studies with larger sample sizes may be required to investigate the role of all the variables separately.

Key Points

Here are the 6 key points from the research paper:

1. The study examined the use of inferior vena cava (IVC) collapsibility index (IVCCI) and caval aorta index (IVC:Ao index) to predict the risk of post-spinal anesthesia hypotension (PSAH) in patients undergoing elective surgery under spinal anesthesia.

2. The researchers conducted a prospective, single-center, observational study in a tertiary care hospital, including 69 adult patients (ASA physical status 1 or 2) scheduled for elective surgery under spinal anesthesia.

3. The results showed that 23 out of 69 patients developed PSAH, and the IVC:Ao index had better sensitivity (0.696 for IVC:Ao index ≤0.810) and specificity (0.717 for IVC:Ao index ≤0.810) in predicting PSAH compared to IVCCI (sensitivity 0.522 and specificity 0.630 for IVCCI ≥33.32%).

4. The researchers found that age and IVC:Ao index had a statistically significant contribution to the development of PSAH, whereas sex, ASA physical status, BMI, and IVCCI did not.

5. The study concluded that the IVC:Ao index is a better predictor of PSAH than IVCCI, and it may be used to assess volume status and guide fluid administration during spinal anesthesia to prevent hypotension.

6. The researchers acknowledged that the sample size was limited due to the COVID-19 pandemic, and further studies with larger sample sizes may be required to investigate the role of all the variables separately.

Reference –

Eeshwar MV, Chari A, Gaude YK, Kordcal AR. Estimating the usefulness of inferior vena cava collapsibility index and caval aorta index to predict hypotension after spinal anaesthesia in adult patients undergoing elective surgery in a tertiary care hospital. J Anaesthesiol Clin Pharmaco