Results
ascites, inferior vena cava collapsibility, depressed, hypotension, hypertensive, COPD
ASCITES, CHRONIC RENAL FAILURE, ISCHEMIC HEART DISEASE, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, COPD, IHD, CHRONIC ATRIAL FIBRILLATION
 Of 176 eligible patients, 17 patients were excluded due to treatment with ACEIs or ARBs, depressed ventricular function, ascites, chronic renal failure on dialysis, COPD or cancellation of surgery. Six patients were withdrawn due to difficult visualization of the IVC. One hundred fifty-three patients completed the study, and their data were considered for statistical analysis (Fig. Study flowchart. ACEIs: angiotensin-converting enzyme inhibitors, ARBS: angiotensin receptor blockers, COPD: chronic obstructive pulmonary disease, EF: ejection fraction, GA: general anesthesia, IVCCI: inferior vena cava collapsibility indexThe mean patients' age was 46.88 y ± 7.58 standard deviation (SD). The mean BMI was 28.01 kg/m2 ± 2.66 SD. A total of 45.6% of patients were males, and 54.2% of patients were females. A total of 92.2% of patients were ASA II, and 7.8% of patients were ASA III. 34% of the studied patients had a history of DM, 5.2% had a history of ischemic heart disease (IHD), and 2.6% had a history of chronic atrial fibrillation (AF). A total of 67.3% of patients were on calcium channel blockers, 24.8% of patients were on β blockers, and 30.7% of patients were on diuretics. Most patients underwent elective craniotomy, lumbar fusion surgery, thyroidectomy, and radical hysterectomy (22.2%, 22.2%, 13.1% and 10.5%, respectively). Other surgical interventions included cervical fusion surgery, mastectomy, discectomy, nephrectomy, tympanoplasty, hemicolectomy, rhinoplasty, splenectomy, and Whipple operation.The mean IVCCI for all patients was 40 ± 11%. The incidence of systemic hypotension after the induction of anesthesia was 40.5% among the studied population. There was no significant difference between patients who developed hypotension after the induction of anesthesia and those who did not regarding patient characteristics except for age. Patients who developed hypotension were significantly older than patients with no hypotension (Characteristics of patients who developed hypotension after induction of anesthesia versus those of patients who did not

 The significantly lowest SAP, MAP and HR values of all patients were those recorded after induction of GA and before tracheal intubation compared to baseline values. After intubation, the average SAP, MAP and HR values were comparable to those recorded as baseline values ((Baseline SAP and MAP values and those recorded after intubation were comparable between patients who developed hypotension after induction of GA and those who did not (Fig.  The average IVCCI of patients who developed hypotension was significantly higher than that of patients who did not (49 ± 8 vs. 33 ± 8% respectively) (The performance of IVCCI % as a predictor of hypotension after induction of GA in hypertensive patients
The performance of IVCCI % as a predictor of hypotension after induction of GA in hypertensive patients (There was a significant positive correlation between IVCCI% before induction of GA and the percentage of maximum SAP drop after induction of GA (