Quest for the Holy Grail: Assessment of dynamic parameters of fluid responsiveness in patients with acute aneurysmal subarachnoid haemorrhage

Introduction: Delta down (DD) >5 mmHg, superior vena cava collapsibility index (SVCCI) >36% and aortic velocity time integral variability (VTI AoV) >20% are reliable predictors of fluid responsiveness in critically ill patients. The aim of this study was to assess the utility of DD, SVCCI, VTI AoV as predictors of fluid responsiveness in patients with acute subarachnoid haemorrhage (SAH) undergoing neurosurgery for clipping of intracranial aneurysm. Methods: After Institutional Ethics Committee approval, prospective pilot study was done on fifteen patients undergoing surgical management of intracranial aneurysm after informed consent. Post-recording baseline vitals, anaesthetic parameters, DD, SVC diameters, VTI AoV, stroke volume, cardiac output and cardiac index (CI), patients received fluid loading (FL) of 15 ml/kg of crystalloids over 30 min. Measurements were repeated post-FL. Response to FL was considered positive if CI increased > 15% from baseline. Statistics: Data expressed as mean ± standard deviation, continuous variables were compared using Student’s t-test. P < 0.05 was considered statistically significant. The predictive abilities of variables for fluid responsiveness determined using Pearson’s coefficient analysis. Results: SVCCI and VTI AoV had high index of sensitivity and specificity for predicting fluid responsiveness in SAH patients; expressing strong correlation with the CI variability. DD > 5 mmHg had high sensitivity and moderate specificity in differentiating responders and non-responders showing good correlation with CI variability. Conclusion: Aortic VTI variation >20% and SVCCI 1 >36% appears to be the more ‘reliable index of fluid responsiveness’ as compared to DD. SVCCI is an excellent predictor of fluid responsiveness and can be easily obtained with basic TEE views.

No conflict of interest has been declared by the author(s).