Quest for the Holy Grail: Assessment of Echo-Derived Dynamic Parameters as Predictors of Fluid Responsiveness in Patients with Acute Aneurysmal Subarachnoid Hemorrhage

BACKGROUND: Acute aneurysmal subarachnoid hemorrhage (aSAH) is a potentially devastating event often presenting with a plethora of hemodynamic fluctuations requiring meticulous fluid management. The aim of this study was to assess the utility of newer dynamic predictors of fluid responsiveness such as Delta down (DD), superior vena cava collapsibility index (SVCCI), and aortic velocity time integral variability (VTIAoV) in patients with SAH undergoing neurosurgery. MATERIALS AND METHODS: Fifteen individuals with SAH undergoing surgery for intracranial aneurysmal clipping were enrolled in this prospective study. Postinduction, vitals, anesthetic parameters, and the study variables were recorded as the baseline. Following this, patients received a fluid bolus of 10 ml/kg of colloid over 20 min, and measurements were repeated postfluid loading. Continuous variables were expressed as mean ± standard deviation and compared using Student's t-test, with a P < 0.05 considered statistically significant. The predictive ability of variables for fluid responsiveness was determined using Pearson's coefficient analysis (r). RESULTS: There were 12 volume responders and 3 nonresponders (NR). DD >5 mm Hg was efficient in differentiating the responders from NR (P < 0.05) with a sensitivity and specificity of 90% and 85%, respectively, with a good predictive ability to identify fluid responders and NR; r = 0.716. SVCCI of >38% was 100% sensitive and 95% specific in detecting the volume status and in differentiating the responders from NR (P < 0.05) and is an excellent predictor of fluid responsive status; r = 0.906. VTIAoV >20% too proved to be a good predictor of fluid responsiveness, with a sensitivity and specificity of 100% and 90%, respectively, with a predictive power; r = 0.732. CONCLUSION: Our study showed that 80% of patients presenting with aSAH for intracranial aneurysm clipping were fluid responders with normal hemodynamic parameters such as heart rate and blood pressure. Among the variables, SVCCI >38% appears to be an excellent predictor followed by VTIAoV >20% and DD >5 mmHg in assessing the fluid status in this population.