Preoperative Evaluation of Inferior Venae Cava Collapsibility Index to Predict Post Induction Hypotension Under General Anaesthesia

Post induction hypotension (PIH) is a largely debated topic in anaesthesia , without any definitive consensus on ideal method for its accurate identification. We hypothesized that inferior venae cava collapsibility index (IVCCI)measured pre-operatively before general anaesthesia could predict this hypotension .The patients were categorized on the basis of their American Society of Anaesthesiologists physical status classification(ASA) to find the optimal cutoff value and sensitivity of this index in predicting PIH.
In this prospective observational study, 157 patients (79 ASA I and 78 ASA II) undergoing routine general anesthesia for surgical procedures were enrolled and their preoperative IVCCI measurements were correlated with non-invasive hemodynamic parameters measured till 12 minutes post induction. The overall incidence of PIH was 46% (12.7% in ASA I and 79.49% in ASA II patients). The optimal cutoff value of IVCCI for predicting hypotension was 47% .The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) at 95%CI was 95% (87-98%), 97% (90-99%), 100% and (90%- 97.1%) with ROC (Receiver operating characteristic) of 0.972 (95%CI, P<0.0001). ASA status (β=2.924, OR (Odd ratio) 18.611;P<0.0001), baseline DBP (β=0.056, OR-0.946; p<0.004) and IVC-CI <50 (β=0.410, OR -1.506; p<0.0001) had significant correlation with PIH in linear regression logistic model.
Preoperative IVCCI measurements, baseline DBP and ASAII physical status of patients could significantly and accurately predict PIH before general anaesthesia.